Essentials of

Endodontics Second Edition

t.me/Dr_Mouayyad_AlbtousH
Essentials of
Endodontics Second Edition

Vimal K Sikri
MDS, DOOP(PU), DEME(AIU), FICD

former Professor and Head

Department of Conservative Dentistry and Endodontics, and
Principal, Punjab Government Dental College and Hospital
Amritsar, Punjab
India

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Disclaimer
Science and technology are constantly changing fields. New research and experience broaden the scope of
information and knowledge. The authors have tried their best in giving information available to them while
preparing the material for this book. Although, all efforts have been made to ensure optimum accuracy of the
material, yet it is quite possible some errors might have been left uncorrected. The publisher, the printer and
the authors will not be held responsible for any inadvertent errors, omissions or inaccuracies.

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 to
Divine energy of
learning and knowledge

I owe, the Almighty God, gratitude for all His blessing

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 Contributors
Ankit Sikri Gomty Mahajan
Associate professor Associate professor
Bhojia Dental College and Hospital Department of Microbiology
Baddi (Himachal Pradesh) 173205 Punjab Institute of Medical Sciences
Email: sikriankit@gmail.com Jalandhar, Punjab 144011
Email: drgomty@gmail.com
Annupriya Sikri
Reader Jyotsana Sikri
National Dental College and Hospital Senior lecturer
Gulabgarh
Sudha Rustagi College of Dental Sciences and Research
DeraBassi 140507 (Punjab)
Faridabad 121003
Email: annupriya05@gmail.com
Email: jyotsanasikri@gmail.com

Arathi Ganesh
Mahantesh Yeli
Professor and Head
Professor and Head
Sri Ramachandran Dental College
SRMC and RI (DU) SDM College of Dental Sciences and Hospital
Porur, Chennai 600116 Dharwad 580009
Email: drarthiganesh@gmail.com Email: mantuuu@yahoo.com

Arpit Sikri Mahima Mohit

Assistant Professor Professor
Sudha Rustagi College of Dental Sciences and Research SDM College of Dental Science
Faridabad 121003 Sattur, Dharwad 580009
Email: arpitsikri@gmail.com Email: mahima702002@yahoo.co.in

B Rajkumar Mamta Kaushik

Professor and Had Professor
BBD College of Dental Sciences Army College of Dental Sciences
BBD University, Faizabad Road ACDS Nagar (Chennapur–CRPF Road )
Lucknow 226028 Jai Jawahar Nagar, Secunderabad 500087
E mail: office@bbdcods.edu.in
Email: mamkaushik@gmail.com

Devendra Chopra
Puneet Girdhar
Reader
Assistant Professor
Saraswati Dental College and Hospital
Punjab Govt. Dental College and Hospital
233, Tiwari Ganj, Chinhat
Amritsar 143001
Lucknow (UP) 227105
Email: drdevendra45@gmail.com Email: puneetgirdhar@gmail.com

Faizal CP Rajesh Pillay

Professor and Head Professor and Head
Kannur Dental College PMS College of Dental Science and Research
Anjarakandy PO Golden Hills, Venkode
Kannur (Kerala) 670612 Trivandrum 695028
Email: drfaizalcp@gmail.com Email: pmscollege@gmail.com

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 viii Essentials of Endodontics

S Balagopal Vasudev Ballal

Vice Principal and Professor and Head of the Department Professor
Tagore Dental College and Hospital Department of Conservative Dentistry and Endodontics
Chennai 600127 Manipal College of Dental Sciences
Manipal 576104
Email: sbalagopal@yahoo.com
Email: drballal@yahoo.com

Shashirekha Govind
Viresh Chopra
Professor Faculty of Endodontology
Institute of Dental Sciences Oman Dental College
K-8, Kalinga Nagar PO Box-835, Mina Al Fahal, Postal Code 116
Bhubaneswar 751003 Sultanate of Oman
Email: shashirekha123@yahoo.com Email: info@omandentalcollege.org

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 Contents ix

Foreword
E ndodontics is fundamental to the modern clinical practice of dentistry. As evidenced by this timely, authorative
book Essentials of Endodontics has over the years, grown and expanded to become a multifaceted branch of the
art and science of dentistry.
As in all branches of dentistry, successful clinical outcomes are highly dependent on the knowledge,
understanding, skill and meticulous attention to detail by the clinician. This book provides the knowledge and
through the careful structuring and presentation by Dr Sikri and the many eminent contributors, the opportunity
to develop a sound understanding of contemporary endodontics. Given the appropriate application of this
knowledge and understanding, those who read and otherwise consult this ‘treasure house’ of information should
be able to look forward to practising highly effective and professionally rewarding endodontics. In this way
Dr Sikri and his colleagues will fulfil their mission in sharing their expert knowledge and understanding,
enthusiasm and quest for excellence in “principle-based” endodontics.
Dr Sikri and his colleagues who have contributed to this highly commendable book, together with the publishers
are to be congratulated on the way in which they have brought together and lucidly presented a considerable
mass of important information in respect of modern endodontics in an easy to read, user-friendly and extensively
illustrated text. This book is a great credit to all those involved in its preparation and publication.
This book is highly recommended to both students and practitioners wishing to provide their patients with
high quality, state-of-the-art endodontics. Endodontics as presented in this book will enhance clinical success in
the management of diseased and damaged teeth with a compromised, let alone nonvital pulpodentinal complex.

Nairn HF Wilson DSc (h.c.), PhD, MSc, BDS, FDS, FFD, FGDP (UK), DRD
Dean and Head of King’s College London
Dental Institute

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 Preface to the Second Edition
A ny book is considered worth reading if readers’ analysis is positively assessed by the author. A good number
of students, after analysing the first edition, suggested modifications in text and flow. Endodontics, being a
dynamic subject, need upgradation on periodic basis; coupled with incorporating wishes of the readers.
Tremendous changes have occurred since the first edition was published; both in our understanding of the
basic biology of the disease process as well as the development of techniques and gadgets used in endodontic
therapy. The focus of second edition is primarily to update the text incorporating all the advances in materials,
instruments and techniques, which have revolutionized endodontics in the past couple of years; and also add
valued knowledge to biological/biocompatible approach in the treatment phase. Recently, advances in microbial
dynamics and understanding of nuances of root canal variations have made endodontic prognosis more predictable.
The present edition is thoroughly updated. A few new chapters are added, viz. Drugs used in Endodontics,
Endodontic Case Selection: Treatment Planning, Ethics in Endodontics, etc. Another few chapters are bifurcated,
expanding text and figures, vis-à-vis the developments in the subject. The important sub-subjects are summarized
in boxes for ready reference of the readers. Many line diagrams and clinical photographs are added in every
chapter for easy to understanding of the text. The language of the text, as usual, is kept lucid and simple.
Summarily, the book will be an asset for the undergraduate and postgraduate students as well as teachers and
practitioners interested in the subject of ‘Endodontics’.
I am thankful to Dr Nitin Verma, Assistant Professor, GDC, Amritsar, for updating the chapter on Surgical
Endodontics. I am whole heartedly grateful to Dr Vivek Hegde (Pune) and Dr Mahalaxmi (Chennai) for
photographs of their endodontic cases. I am thankful to my students, Dr Tejinder, Dr Komal, and Dr Neha for
reading the manuscript.
Completing this book would not have been possible without contributions from multitude of academicians
and eminent teachers. My wife, Dr Poonam Sikri, my sons, Dr Ankit, Dr Arpit and my daughter-in-laws,
Dr Annupriya, Dr Jyotsana whole-heartedly supported me in this adventure.
Last but not the least, I am thankful to all those who helped me directly or indirectly in compiling the manuscript
of the book.
I look forward to your suggestions, comments and criticism for future improvement in the book.

Vimal K Sikri

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 Preface to the First Edition
O ver the years in my profession, I have realized that there is no limit to learning much more in the subject you
think you know well. In more than three decades of my teaching career, I have always encouraged my
students to raise more and more questions. Students’ queries have provided me with an enriching experience that
has endorsed my belief that learning is a never ending process. The knowledge that gathered in these years,
complimented with my long clinical experience is all enshrined in this book Essentials of Endodontics.
It has been rightly said that knowledge lies in the accumulation of the facts and wisdom in its simplification.
The book in your hand is simple and comprehensive, made to serve as an introductory text for students as well as
a useful guide for the practitioners. The concepts presented in the book have been developed over the time under
the influence of my teachers and co-operation of my colleagues and students.
Like all sciences, endodontic therapy is also based upon sound principles. Every effort has been invested to
make this book authentic, scholarly and self-evident. Color coded key information boxes serve as easy to use
navigational aids for the students. While going through the text the readers will find solutions to myriad endodontic
challenges. A chapter ‘Resinifying therapy in endodontics’—a solution to many endodontic problems has been
added for the benefit of clinicians and practitioners.
A loving heart is said to be the beginning of all knowledge. I am sincerely grateful to Almighty God, the
constant source of my strength for bestowing upon me that requisite heart. I have had the good fortune of working
under a great teacher, Dr SS Dua, whose blessings and continuous patronage have led this book to see the light of
the day.
I would like to extend special thanks to all those who have contributed their experiences in the form of text and
photographs in this book. I extend my gratitude to my colleagues in the department, Dr Renu Bala Sroa, Professor;
Dr Baljeet Sidhu, Demonstrator and Dr Jagan Jyot, Medical Officer whose suggestions have been carefully
considered and acted upon. Dr Nitin Verma has been of valuable help in re-organizing the chapter on ‘Surgical
Endodontics’. I am thankful to Mr Vipul for making beautiful Corel diagrams, to Mr Ashwani Mahajan for his
ready-to-help attitude and to Dr Puneet Girdhar and Dr Sachin Dev Mehta for bearing with my over-occupation
especially during travelling. I express my heartfelt thanks to Dr Anil Chandra of CSJM Medical University,
Lucknow, Dr Deepak Grover and Dr Gurpreet of National Dental College, DeraBassi, Dr Aamir of Govt. Dental
College, Srinagar, Dr lsha Narang of BHU, Varanasi and Dr Agam Bhatnagar of SGT Dental College, Gurgaon for
contributing in the form of photographs. I eulogize the efforts of my students Dr Gulvinder, Dr Payal, Dr Amrit
Preet, Dr Preeti Jain, Dr Meenu Garg, Dr Ruchika Arora, Dr Laxmi Gahlot, Dr lsha Sood, Dr Garima Malhotra,
Dr lbadat Preet Kaur, Dr Shalini Sinha, Dr Mandeep Kaur, Dr Priyanka Setia and Dr Shikha Sharma for organizing
manuscript and the photographs.
Last but not the least I am thankful to my wife, Dr Poonam and my dear sons, Dr Ankit and Arpit for their
encouragement during preparation of this manuscript and also during countless hours of organizing and editing
the text.
A book is a treasure house upon which we can draw again and again and I hope this book proves to be a real
one.

Vimal K Sikri

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 Contents
Contributors vii
Foreword by Nairn HF Wilson ix
Preface to the Second Edition xi
Preface to the First Edition xiii

1. Introduction to Endodontics 1 Non-narcotic/non-opioid analgesics 35

Definitions 1 Opioid analgesics 36
Scope of endodontics 1 Corticosteroids 37
Evolution of endodontics 1 Alternative analgesics (acupuncture) 39
Outcome of endodontic therapy 6 Management of infection (antibiotics) 40
Factors of prognosis 6 Antibiotic prophylaxis 43
Future of endodontics 7 Antibiotic use: Risk and precautions 44
2. Biology of Pulp–Dentin Complex 9 Drug resistance 45
Structure of dentin–pulp complex 9 Injudicious use of antibiotics (antibioma) 45
Development of dentin–pulp complex 10 Antiemetic drugs 46
Dentin 10 Vitamins and mineral supplements 46
Chemical composition 11 5. Diseases of Dental Pulp 48
Components of dentin 11 Pulpal inflammation 48
Dentin permeability 13 Causes of pulp diseases 49
Smear layer and smear plugs 14 Physical 49
Pulp 14
Chemical 51
Components of pulp 15
Bacterial 51
Vascularity of the pulp 16
Classification of pulp diseases 52
Interstitial fluid pressure 16
Hyperaemia 54
Nerve impulses in pulp 16
Pulpitis 55
Pulp–dentin complex regeneration: Biological cues 16
Pulp degeneration 59
3. Pathophysiology of Pain 19 Pulp necrosis 60
Odontogenic pain 19
Pre-endodontic pain 19 6. Diseases of Periradicular Tissues 63
Reversible pulpitis 19 Definition 63
Irreversible pulpitis 20 General features 63
Pulp necrosis 20 Periradicular diseases of endodontic origin 66
Periradicular inflammation (apical periodontitis) 21 Acute periradicular lesions 66
Referred pain 22 Chronic periradicular lesions 68
Inter-appointment endodontic pain (flare-up) 22 Periradicular lesion of non-odontogenic origin 74
Microbial and latrogenic causes 23
7. Rationale of Endodontic Treatment 78
Inflammatory events 24
Inflammation 78
Risk factors 24
Components of inflammation 78
Treatment 25
Cellular events 78
Post-endodontic pain
Vascular changes 80
Non-odontogenic pain 26
Tissue changes 81
4. Drugs used in Endodontics 30 Zones of inflammatory reactions 82
Sedative–hypnotic drugs 30 Implications of residual infection before and after
Anesthetic agents 32 root canal treatment 83

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xvi Essentials of Endodontics

Repair following endodontic treatment 84 Systemic diseases influencing treatment planning 142
Endodontic infections and systemic reactions 86 Periodontal diseases influencing treatment planning 144
Endodontic treatment and allergic reactions 86 Final phase of treatment planning 145
Healing of sinus tract 86 To refer or not to refer: Clinical protocol 146
8. Endodontic Microbiology 90 11. Endodontic Instruments 150
Microbes in endodontic diseases 90 Standardization of endodontic instruments 150
Rare endodontic infections 92 Make of endodontic instrument 151
Microflora of root filled teeth 93 Evolution of nickel-titanium instruments 152
Extraradicular infections 94 Terms used with endodontic instruments 152
Microbial diagnostic techniques 95 Fracture of Ni-Ti instruments 153
Culture 95 Classification of instruments 154
Microscopic examination 95 Diagnostic instruments 154
Immunological methods 95 Exploring instruments 154
Molecular methods 96 Extirpating instruments 155
Microbial interactions in infected root canals 99 Shaping instruments 156
Host-microbe interactions 99 Obturating instruments 159
Interaction among micro-organisms 99 Miscellaneous rotary systems 176
Biofilm in endodontic infections 100 Clinical recommendations (Do’s and Don’ts) 179
Enterococcus faecalis: Significance in endodontics 103 Newer rotary designs 179
Potential role of enterococci in unsuccessful root 12. Sterilization of Endodontic Instruments 187
canal treatment 104 Sterilization of operating room 187
9. Diagnosis and Diagnostic Aids 108 Sterilization of instruments 187
Patient assessment 108 Sterilization of handpiece and turbines 192
Clinical examination 110 Sterilization of miscellaneous instruments 193
Extraoral examination 110 13. Anatomy of Pulp Spaces 195
Intraoral examination 110 Relationship of pulp chamber to clinical crown 196
Clinical inspection methods 112 Anatomy of apical-third of root canal 197
Pulp vitality tests 115 Apical constriction 197
Tests assessing the neural status of pulp 116 Cementodentinal junction 197
Tests assessing the blood supply of pulp 119 Apical foramen 199
Radiographic techniques 121 Anatomic complexities in root canal system 199
Conventional radiography 121 Radix entomolaris and radix paramolaris 199
Radiovisiography 124 C-shaped canals 200
Xeroradiography 125 Accessory/lateral canals 202
Digital subtraction radiography 125 Apical delta 203
Computed tomography (CT) 126 Isthmus 203
Magnetic resonance imaging (MRI) 127 Root canal curvatures 203
Cone beam computed tomography (CBCT) 127 Horizontal dimensions of root canal 205
C-arm imaging 132 Classification of root canal anatomy 205
Tests measuring tooth temperature 132 Weine’s classification 205
Newer methods 133 Vertucci classification 206
Ultrasonic imaging 133 Ahmed and Dummer classification 207
Computer expert system 134 Configuration of pulp spaces in individual teeth 207
Laser optical disc storage 134 Maxillary teeth 207
Mandibular teeth 215
10. Endodontic Case Selection:
Development anomalies and root canal system 225
Treatment Planning 138
Endodontic treatment vs osseointegrated 14. Access Cavity Preparation 232
implants 138 Basic principles of endodontic treatment 232
Case selection (treatment planning) Pain management 232
in endodontics 139 Sterilization 232

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 Contents xvii

Drainage-trephination 232 Carbamide peroxide (glyoxide) 294

Immobilization 233 Maleic acid 294
Isolation (rubber dam application) 233 Chelating agents 294
Access cavity preparation 241 MTAD 295
Objective of access cavity preparation 241 Tetraclean 296
Rules for access cavity preparation 242 Bioactive glass 296
Armamentarium for access cavity preparation 242 Electrochemically activated solutions 296
Phases of access cavity preparation 243 Ozonated water 297
Pre-endodontic build-up technique 245 Carisolv 297
Conservative access cavity preparation 246 Photon-activated disinfection 297
Cavity design for individual teeth 247 Herbal irrigants 297
Maxillary anterior teeth 247 NanoCare plus 298
Mandibular anterior teeth 251 Efficacy of Irrigants 299
Access cavity preparation in difficult cases 254 Irrigating techniques 301
Conventional technique 301
15. Working Length and Working Width 256
Sonic irrigation 302
Anatomy of the root apex 256
Ultrasonic irrigation 303
Apical terminus of root canal preparation
Negative pressure irrigation 304
and obturation 257
Irrivac needle pressure system 305
Assessing apical constriction area 258
VATEA self-adjusting file (SAF) system 305
Types of apex locators 260
Intracanal aspiration technique 305
Endodontic working width 266
Complications during root canal irrigation 305
Need to enlarge apical constriction area 268
Intracanal medicaments 308
16. Cleaning and Shaping of Root Canals 270
19. Root Canal Sealers 314
Objectives of root canal preparation 270
Biophysical properties of root canal sealers 314
Instrument motions during root canal preparation 271
Classification 316
Root canal preparation: Concepts/terms 272
Individual sealers 316
Techniques of root canal preparation 273
Zinc oxide-based sealers 316
Apical-coronal techniques 273
Medicated zinc oxide eugenol sealers 319
Coronal-apical techniques 277
Resin-based sealers 320
17. Endodontic Smear Layer 281 Gutta-percha in organic solvents 324
Factors influencing formation of smear layer 282 Cements as sealers 324
Management of smear layer 282 Silicone-based sealers 324
Removal of smear layer 283 Calcium hydroxide-based sealers 325
Mechanical removal 283 Bioceramic-based root canal sealers 327
Chemical removal 284 Miscellaneous sealers 332
Ultrasonics 287 20. Obturation of Root Canal Spaces 335
Lasers 287 Apical termination of obturation 335
Overfilling and overextension 336
18. Root Canal Irrigants and Medicaments 290
Requisites for an ideal irrigant 290 Materials used for obturation: Classification 336
Classification of irrigating solutions 290 Gutta-percha 337
Silver cones 351
Commonly used irrigants 291
Miscellaneous obturating techniques 353
Normal saline 291
Obturation of apical third area 357
Sodium hypochlorite 291
Pastes as obturating materials 360
Chlorhexidine 292
Retrograde (root end) filling materials 361
QMix 293
Hydrogen peroxide 293 21. Single-visit Endodontics 366
Iodophors (iodine potassium iodide) 293 Indications and contraindications 370
Chlorine dioxide 294 Criteria for single visit endodontics 371

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xviii Essentials of Endodontics

22. Postendodontic Restorations 373 27. Root Resorption 489

Effect of root canal treatment on the tooth 373 Etiology 489
Selection of restoration for endodontically treated Pathogenesis 490
teeth 374 Classification 490
Tooth restorability index (TRI) 374 External resorption 491
Classification guiding the choice of restoration 377 External inflammatory resorption 491
Postcore restorations 378 External cervical resorption 492
Functions of post 379 External replacement resorption 494
Classification of post 379 External surface resorption 495
Types of post 379 External transient apical breakdown 495
Ferrule effect 389 External root resorption of non-dental origin 495
Cores 401 Internal resorption 496
Restoration of teeth after root amputation 403 Internal inflammatory resorption 496
internal surface resorption 496
23. Endodontic Emergencies 409 internal replacement resorption 497
Classification 409 internal transient apical breakdown 497
Pretreatment emergencies 410 Internal root resorption of non-dental origin 497
Mid-treatment emergencies 418 Idiopathic root resorption 498
Post-treatment emergencies 420
28. Pediatric Endodontics 501
24. Bleaching of Discolored Teeth 422 Differences in primary and permanent teeth 501
Tooth discoloration and staining 422 Diagnosis 503
Bleaching of teeth 424 Pulp therapy 504
Additional materials used during bleaching Apexification/apexogenesis 517
procedure 425 Use of antibiotics in pediatric endodontics 517
Techniques of nonvital in bleaching 432
29. Geriatric Endodontics 520
Adverse effects of bleaching 437
Changes due to ageing in oral-dental tissues 520
25. Vital Pulp Therapy 441 Endodontic treatment in elderly 521
Healthy pulp and primary trauma 441 History and clinical examination 521
Indirect pulp capping/indirect pulp treatment 443 Diagnosis 522
Direct pulp capping 446 Treatment planning 523
Pulp curettage 450 Preparation before endodontic treatment 523
Partial pulpotomy 452 Endodontic procedures 523
Challenges in treating elderly patients 524
Pulpotomy 454
Management of root exposure 524
Apexogenesis (root formation) 455
Apexification (root end closure) 456 30. Magnification in Endodontics 527
Magnification types 527
26. Traumatic Injuries and Management 461
Ergonomics 529
Traumatic Dental Injuries: Types and Common terms used in magnification 530
nomenclature 461
Parts of the microscope 530
Classification 462
Magnification 530
Root fractures 465 Illumination 532
Cracked tooth syndrome 470 Accessories 533
Management of patient with dental trauma 473 Uses of operating microscope in endodontics 524
Management of soft tissue injuries 474 Diagnosis 534
Management of hard tissue injuries 475 Non-surgical endodontic procedures 534
Healing of root fracture 481 Surgical endodontics 536
Storage medium 485 Documentation and patient education 538
Fracture of alveolar process 487 Marketing and practice management 538

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 Contents xix

31. Lasers in Endodontics 539 34. Endodontic–Periodontal Relationship 588

Principle of laser 539 Periodontal pulpal interrelationship 588
Components of laser device 539 Classification of endodontic periodontal lesions 589
Laser tissue interaction 541 Simon’s/Cohen’s classification 589
Classification of laser 541 Grossman’s classification 589
Types of lasers 542 Weine’s classification 590
Application of lasers technology in endodontics 545 Diagnosis 591
Laser hazards 551 Treatment 592
Laser safety 551
Primary endodontic lesions 594
32. Surgical Endodontics 553 Primary periodontal lesions 594
Indications and contraindications 553 Combined lesions 594
Classification of surgical endodontic procedures 553
35. Endodontic–Orthodontic Continuum 597
Preoperative assessment 554
Implications of orthodontic tooth movement 597
Presurgical evaluations 554
Effect of orthodontic tooth movement on pulp 597
Premedication 555
Orthodontic force and root resorption 598
Preparation of the surgeon and the patient 555
Orthodontic tooth movement and periapical
Preparation of the surgical site 555
lesions 599
Local anaesthesia 555
Endodontic surgery and orthodontic forces 599
Classification of local anesthetics 557
Orthodontic extrusion (forced orthodontic eruption) 600
Techniques of regional anaesthesia 558
Complications of anaesthesia 563 Orthodontic behaviour of endodontically treated
teeth 601
Advances in local anaesthesia 563
Failure of anaesthesia in endodontic procedures 564 36. Endodontic Failure and Retreatment 603
Principles of surgery 564 Basis of success and failure 603
Suture materials 569 Causes of failure 603
Surgical needles 570 Nonsurgical retreatment 605
Closure of surgical sites 571 Indications and contraindications 605
Methods of suturing 572 Objectives of retreatment 605
Surgical armamentarium 573
Treatment planning 605
Surgical procedures 574
Management of endodontic failures 606
Osseous entry (osteotomy) 574
Coronal leakage 606
Apicoectomy (root-end resection) 574
Inadequate root canal treatment 606
Guided tissue regeneration (GTR) 576
Missed canals 615
Autotransplantation 578
Decompression of large periradicular lesions 578 Canal blockage 615
Perforation repair 579 Ledges 616
Hemisection/bicuspidization/radisectomy 579 Canal transportation 616
Electrosurgry 580 Perforation 617
Cryosurgery 581
37. Resinifying Therapy in Endodontics 621
Postoperative care 581
Utility of resinifying therapy 622
33. Endodontic Implants 584 Resinifying agent as an obturating material 622
Indications 584 Resinifying agent as a direct pulp capping
Contraindications 584 material 624
Patient selection 585 Resinifying agent as a sealer 624
Implant materials and designs 585 Resinifying agent as a material for temporization 625
Implant placement 587 Resinifying agent in complications 625

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xx Essentials of Endodontics

38. Regenerative Endodontics 627 Ethical dilemmas 641

Important studies 627 Ethical principles 642
Tissue engineering 628 Advertising in dentistry 644
Triad of tissue engineering 629 Standard of care 645
Clinical applications of tissue engineering 632 Endodontic referrals 647
Negligence and malpractice 647
Limitations of regenerative procedures 637
Ethics in endodontic research 649
39. Ethics in Endodontics 640 Laws in dentistry 650
Modern version of the Hippocratic oath
(revised in 1964 by Louis Lasagna) 641 Index 653

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Chapter
1
Introduction to
Endodontics

Endodontics, the name derived from ‘Endo’ means • Surgical intervention of pulpal problems (apico-
inside, ‘Dont’ means the tooth and ‘ics’ means the study; ectomy, hemisection, etc.)
that is, the study of inside of the teeth. The pulp, which • Developmental anomalies of pulpal tissue.
is inside the tooth, is a specialized connective tissue
encased by dentin. The dentin is further covered by EVOLUTION OF ENDODONTICS
enamel in the coronal part and cementum in the
The evolution of scientific development in endodontics
radicular part. The collective study of physiology and
dates from the third decade of 17th century. Literature
pathology of pulpal tissue along with their sequalae is
on the early history of endodontics is sparse and
‘Endodontics’.
undocumented as early history of dentistry. The
beginning of endodontics is both slow and late. It was
DEFINITIONS further retarded by the focal infection theory. Only in
The science dealing with diseases of pulp and the peri- 1956, it attained a degree of acceptability and respect
apical tissues is endodontics. It is defined as ‘the division when the American Board of Endodontics was
of dental science that deals with etiology, diagnosis, treatment established.
and prevention of diseases of dental pulp and their sequelae’. An archaeological excavation by the department of
antiquities and museums in northern Negev desert
SCOPE OF ENDODONTICS (Israel) recovered the skeletal remains of 25 people
Pulpal and periapical diseases are common in dentistry. buried in a mass grave approximately in 200 BC.
Untreated cases lead to bone destruction and sub- Subsequent analysis of the dentition showed one
sequent extraction of the concerned tooth. Endodontics skeleton with a 2.5 mm bronze wire implanted in
provides treatment to such cases and the tooth can be maxillary right lateral incisor. This is the first
saved; protecting stomatognathic system in functions. archaeological evidence of endodontic procedure
Endodontics can be beneficial in variety of cases, such performed in ancient Israel, which is documented.
as: On the radiograph, the root canal appears to have
• Pulp exposures (complete or partial) been artificially widened to a depth of 2.5 mm in
• Periapical abscess preparation for insertion of the wire. This implies direct
• Root fractures intervention by a skilled dental practitioner rather than
a haphazard procedure performed by a layman.
• Root perforations
The pulp of an aching tooth was often cauterized
• Teeth with incomplete apical root development
either by a red-hot cautery or by means of a chemical
• Endodontic implants
or a weak acid. The use of a hot wire has been
• Replants mentioned by F. Hoffman (1753) in his book A Treatise
• Transplants (autotransplants or allotransplant) on the Teeth; their Disorders and Cure.
• Occlusal trauma causing reversible pulpitis Josiah Flagg of Boston, the first American to practice
• Overzealous root planing and curettage, leading to dentistry exclusively, relieved pain of an abscessed
pulpal sensitivity tooth by creating an opening into the crown, leading
• Extensive infrabony pocket formation extending to the pulp cavity. He named this operation as ‘tapping
beyond the root apex the pulp’.

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 2 Essentials of Endodontics

Although the pulp was left to die by cauterization, reported use of electric current to measure root canal
or intentionally devitalized by heat or chemicals; its working length. Eventually Sunada in 1962 introduced
intentional removal was not planned until 1824 when electronic apex locators.
Delmond of Paris devised a fine, hooked instrument In early 1930’s, silver cones were introduced for
for that purpose. The removal of the pulp was less filling root canals by H. Trebitsch and later modified
painful and effective with this instrument. by E. Jasper of St. Louis.
In 1838, Edwin Maynard took a watch spring and The first cement was used in dentistry in 1856. A crude
filed it down to make a four-sided broach, which can composition of zinc oxide and a solution of zinc chloride
entwine and remove the pulp easily. Robert Arthur cut known as oxychloride of zinc was popular at that time.
barbs on broaches with a penknife in 1853. In 1885, the Two outstanding English dentists, John Hunter, who
Gates Glidden drill and in 1904, the K-file were intro- wrote, ‘The Natural History of Human Teeth (1778)’,
duced. Standardization of instruments was proposed and Joseph Fox strongly advocated transplantation of
by Trebitsch in 1929 and again by Ingle in 1958 but again tooth. Hunter used to boil the teeth before transplan-
meant to be reviewed for rotary Ni-Ti instruments. tation. Since venereal diseases were rampant, boiling
Following removal of the entire pulp, radicular space of teeth was preferred. However, it was not done for
preparation was done by step-back or telescopic reasons of sterility but rather for removal of the attached
technique since 1969 as first described by Clem and soft tissue. Hunter first successfully implanted a human
Weine. Another major breakthrough for root canal tooth in a cock’s comb.
preparation as crown down technique was given by James Gardette, (1950) another Philadelphia dentist,
John Pappin and Marshall in 1980, followed by is given credit for intentional replantation of teeth in
“Balanced force” concept by Roane in 1985. America.
Philip Pfaff performed the conventional pulp In 1864, Stanford C. Barnum of New York invented
capping of diseased pulp in 1756. In 1874, Adolf Witzed rubber dam for keeping the operative field clear of
of Germany tried pulp mummification with different saliva and soft tissues.
materials. In 1836, in “Guide to sound Teeth”, Otto Walkoff in 1891 introduced camphorated
Shearjashub Spooner introduced a technique for pulp monochlorophenol as an intracanal medicament, which
devitalization of the pulp by arsenic. This technique he found to be more effective and less irritating.
continued for well over 100 years. Chapin A. Harris of Wilhelm Konrad Roentgen discovered X-ray in 1895.
Baltimore, one of the founders of the first dental school, Two weeks after Roentgen announced his discovery, a
who also used the drug at the same time; however, he pioneer in endodontics, Professor Otto Walkhoff, took
warned against its use because of arsenic potential to radiograph of his own teeth, exposing the plate for
damage the teeth and soft tissue. About the middle of 25 minutes.
the 19th century, efforts were made to conserve the pulp In 1906, Dr John P Buckley mixed cresol with
with medicaments such as creosote, Canada balsam and formalin, which became known as Formocresol, and is
alcohol. The agent used was wiped over the exposed still the favoured intracanal medicament among
pulp and it was capped with metal disk, oiled silk, practising endodontists.
asbestos, plaster of Paris, lead or tin foil, collodion, etc. Until the late 1850s, ice and heat had been used to
determine whether the pulp was dead or alive. In 1867,
Root canal filling actually preceded removal of the
Magitot of France, suggested the use of an electric
entire pulp. After the removal of the pulp, the canal
current to determine if vitality was present in a tooth.
was filled with some foreign substance often gold foil.
However, Marshall in 1891 popularized it. Focal
Documentary proof of gold foil fillings in 1809 by
infection theory promulgated by William Hunter in
Edward Hudson of Philadelphia is available. In 1890, 1910 was blindly followed in dentistry, particularly in
Gramm used copper points, which were plated with root canal treatment.
gold to prevent dissolution.
Local anesthesia was discovered in 1884, when at the
Guttapercha, an extract of trees of sapodilla family, suggestion of Sigmund Freud; Carl Koller, a Viennese
mixed with lime, quartz and feldspar; was introduced ophthalmologist, first used a solution of cocaine as a
in 1850 and marketed under the name of Hill’s stopping. topical anesthetic for eye surgery. In 1885, William S.
In 1867, GA Bowman of St. Louis used guttapercha Halsted of New York, made the first block injection (a
points for filling of root canals. mandibular bone) with the cocaine solution. Myer in

1 Working length determination was performed by

radiographic technique since 1908 as first described by
Meyer L. Rhein. In 1918, Custer for the first time
1904 developed ‘Myer Dental Obtunder’ a high-
pressure syringe for anesthetizing the pulp and in 1906
infiltration anesthesia was introduced by Vaughan.

t.me/Dr_Mouayyad_AlbtousH
 Introduction to Endodontics 3

The placement of calcium hydroxide as a sub-base in EDTA, Cetrimide, NaOH) in 1980. Salvizol another root
deep cavities where the removal of all decay would expose canal chelating agent with broad spectrum bactericidal
the pulp (indirect pulp capping) has been used success- activity (5.0% aminoquinaldinium diacetate) was
fully since its introduction by Walter Hess in 1951. introduced by Kaufman in 1981. Torabinejad first used
Numerous agents are being used for smear layer MTAD containing citric acid and doxycycline as
removal from the root canals, like EDTA (15% decalcifying substances in 2003.
Ethylenediaminetetraacetate acid) since 1957 by
The period of dentistry in the early part of 20th
Nygaard-Ostby followed by Fehr in 1963 who
introduced EDTAC (15% EDTA + Cetrimide) and century was characterized by the introduction of basic
Steward 1969 RC Prep (10% urea peroxide + 15% sciences, especially Endodontics. As we go back to
EDTA). Citric acid in 40% concentration was first used 200 years of progress in endodontics, it is almost like
by Tidmarsh in 1978 followed by 20% concentration comparing the stone age with the present technologies
by Wayman (1979) and 10% citric acid by Baugmgartner (Table 1.1). Various sciences have contributed to a much
(1984). Koskinen reported the success of several cases better understanding of the physiology and pathology
using Tubulicid (38% benzalkonium chloride, EDTA, of pulp, enabling us to examine and compare it in health
50% citric acid) in 1975 followed by Largal Ultra (15% and disease.

Table 1.1 Evolution of Endodontics

200 BC First evidence of endodontic dentistry with 2.5 mm bronze wire in maxillary right lateral incisor
500 AD Aetius first recorded endodontic surgical procedure (the incision and drainage of an acute abscess)
1725 Lazare Riviere used clove oil as obtundent, later used oil of cinnamon, camphor or turpentine
1728 Pierre Fauchard in his textbook “Le Chirurgien Dentiste” first described dental pulp
1746 Pierre Fauchard described removal of pulp
1753 F. Hoffman advocated cauterization of pulp with hot wire
1756 Philip Pfaff described pulp capping of diseased pulp
1757 Bourdet described a therapy of extracting carious teeth, followed by filling the canals with gold and re-implanting them
1778 John Hunter advocated re-implantation when crown was partially destroyed due to caries
1783 Woofendale used cautery for destroying the pulp to relieve pain
1809 Edward Hudson plugged root canal with gold foil in anterior teeth only
1820 Leonard Koecker used hot wire for cauterization of exposed pulp and covered with a lead foil for its cooling effect
1824 Delmond devised a fine, hooked instrument for pulp extirpation
1836 Shearjashub Spooner advised pulp devitalization by Arsenic
1838 Edwin Maynard filed an instrument into a four sided broach
1839 World’s first dental journal was introduced
1847 Edwin Truman introduced gutta-percha as a filling material
1850 Hill introduced Guttapercha mixed with lime, quartz and feldspar marketed under the name of Hill’s stopping
1850 WW Codman confirmed that the aim of pulp capping proposed by Koecker in 1821, was to form a dentin bridge
1853 Robert Arthur introduced barbs and handles on broaches
1864 Stanford C. Barnum introduced rubber dam
1866 Chase introduced pulp mummification
1867 GA Bowman introduced gutta-percha points for root canal filling
1867 Magitot suggested use of electric current to determine vitality of pulp
1879 Witzel introduced phenol
1880 Brophy used heat to check the status of pulp, traced sinus tract
1883 Perry used gutta-percha wrapped around a gold wire
1883 WE Harding differentiated between pulp capping of an accidental and intentional exposure

1
1884 Carl Koller firstly used topical local anaesthesia with cocaine
1885 Lepkoski advised use of formalin despite of arsenic to ‘dry’ pulp
(Contd…)

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 4 Essentials of Endodontics

Table 1.1 Evolution of Endodontics (Contd…)

1885 William S Halsted described first local anesthesia block injection, a mandibular nerve block with a cocaine solution
1890 Gramm introduced copper points for filling root canals, later gold plated them to prevent discoloration
1891 Otto Walkoff introduced camphorated monochlorophenol as intracanal medicament
1900 Price described periapical radiolucencies as ‘blind abscesses’ and advised use of radiographs for diagnosis of
pulpless teeth
1904 Frank Billings directed attention on relationship between oral sepsis and bacterial endocarditis
1904 Myer introduced High Pressure Syringe for anesthetizing the pulp, ‘Myer Dental Obtunder’
1906 Vaughan introduced infiltration anaesthesia
1906 John P Buckley introduced formocresol
1908 Meyer L Rhein introduced a technique for determining canal length and level of obturation
1909 EC Rosenow developed the theory of ‘focal infection’ in a study of bacterial aspects of root canal treatment
1910 William Hunter devised ‘focal infection theory’
1918 Custer investigated the electronic method for root length determination
1930 BW Hermann introduced calcium hydroxide
1930 H Trebitsch introduced silver cones for root canal filling
1955 Kuttler defined the apical anatomy of cemento-enamel junction with regard to working length determination
1957 Richman credited with the use of ultrasonics in endodontics
1957 Nygaard-Ostby introduced EDTA (ethylenediaminetetraacetate acid)
1960 Theodore H Maiman introduced LASER
1961 Ostby described role of blood clot in endodontic therapy
1962 Sunada introduced electronic apex locator
1963 Fehr introduced EDTAC (15% EDTA + Cetrimide)
1965 Leon Goldman first use laser on a tooth
1966 Frank described apexification technique
1969 Clem and Weine introduced ‘Step-back’ or telescopic technique for root canal preparation
1969 Steward introduced RC prep (10% Urea peroxide and 15% EDTA)
1971 Weichman first attempt to use laser in endodontic surgery
1971 Inoue developed electronic apex locator Sonoexplorer (low frequency electronic apex locator)
1974 Schilder described vertical compaction of guttapercha
1977 FS Yee introduced obtura unit for root canal filling
1977 Baumann described the use of operating microscope in endodontics
1978 Ben Johnson introduced Thermafil
1978 Apotheker and Jako: Concept of extreme magnification in the form of operating microscope
1979 McSpadden introduced the Thermomechanical compaction
1979 Detsch described the use of endoscope in endodontic diagnosis
1979 Cox and Cooke first described C shaped canal
1980 John Pappin and Marshall introduced ‘Crown-down’ preparation for canal preparation
1981 Chayes-Virginia Inc.: Dental operating microscope (named Dentiscope)
1983 Cvek introduced partial pulpotomy
1984 Baumgartner used citric acid (10%) for smear layer removal in root canals
1985 Roane introduced ‘Balance Force’ concept for canal preparation
1986 Hasegawa introduced Endocater (high frequency electronic apex locator)
1987 Harmeet Walia introduced Nickel-Titanium instruments in endodontics

1 1989 S Senia introduced light speed instruments

(Contd…)

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 Introduction to Endodontics 5

Table 1.1 Evolution of Endodontics (Contd…)

1990 Carlsen and Alexandersen described Radix entomolaris
1993 Torabinejad developed mineral trioxide aggregate (MTA)
1993 Lussi, Nussbacher Grosrey described non-instrumentation technique
1993 APIT/Endex (third gen Electronic apex locator) developed by Frank and Torabinejad
1994 Ben Johnson introduced Profile instruments
1995 McSpadden introduced Quantec instruments
1996 Buchanan introduced Hand Greater taper files
1996 Hoshino and Colleagues introduced Triple antibiotic paste
1999 Endox system was introduced by Haffner and colleagues
1999 Bingo 1020 (fourth generation apex locator)
2000 Edward Lynch and Aylin Bayson developed Healozone
2000 Arias introduced electrochemically activated water as irrigation solution
2001 Clifford Ruddle and team developed protaper system in co-operation with Dentsply
2001 Micro-mega developed Hero Shapers
2002 John McSpadden introduced K3 Endo
2003 Jai and Albert introduced Resilon as an obturating material
2003 Torabinejad introduced irrigant MTAD (4.25% citric acid, 3% doxycycline, 0.5% Tween 80)
2004 Dr Goodis introduced V-taper
2005 Zehnder introduced irrigant HEBP (7% 1-Hydroxyethylidene-1,1-bisphosphonate)
2005 Liberator was introduced by Miltex
2006 Protaper Universal system was introduced
2006 Fukumoto introduced intracanal aspiration technique
2006 Koch and Brave introduced Activ GP
2007 Franklin introduced Monobloc concept
2007 Endovac was introduced by Hoafs and D Edson
2007 Tulsa dental specialities introduced M wire technology
2007 Greater taper series X was introduced by Dr S Buchnan
2008 Dr Richard Mounce introduced Twisted file
2008 Ghassan Yared introduced a concept of canal preparation using only one NiTi rotary instruments
2009 Pierre Machtou, Bob Sharp and Cliff Ruddle introduced endoactivator irrigation system
2009 George Eliades introduced vibringe irrigation system
2009 Endosequence post preparation technique was developed by Dr Ali Nasseh
2010 Redent Nova introduced self adjusting file
2010 Ghasson Yared introduced Reciproc
2011 Dentsply introduced Wave One
2012 FKG Dentaire introduced RaCe
2012 Coltene-Whaledent introduced Hyflex-CM
2012 Micro-Mega introduced Revo-S file
2013 Micro-Mega introduced One shape
2013 Dentsply introduced ProTaper Next
2014 Neolix France introduced NeoNiTi file system
2015 Coltene-Whaledent introduced Canal Pro Cr-2 Endomotor with reverse motion
2015 File retrieval kit by Dr Yoshi Teruachi
2016
2017
Autosyringe introduced by vista dental
Carl Zeiss introduced Civil Zeiss extara 300
1

t.me/Dr_Mouayyad_AlbtousH
 6 Essentials of Endodontics

OUTCOME OF ENDODONTIC THERAPY d. Periodontal condition: The preoperative periodontal

In biology, the term ‘outcome’ can never be defined. condition of the tooth does not influence prognosis
Age old phrase ‘body tissues never follow text’ is true of the endodontic therapy. Periodontal diseases may
in all therapies; equally true in endodontics. The advance on its own rate, subsequently tooth loss
‘outcome’ is based on several factors, and taking care becomes imminent.
of each of these factors can minimize failures; however, e. Systemic health: The influence of systemic health has
one factor ‘iatrogenic’ is beyond the control of all of us. not been established to a great extent; however, it is
Therefore, the prognosis (the forecast of a disease) may seen that medically compromised patients are at high
not be definite. risk of developing infections.
In endodontic therapy, the term ‘prognosis’ applies Intraoperative Factors
to chances of healing; thereby, saving the tooth. The a. Apical extent of treatment: Extrusion of filling materials
outcome of the treatment is evaluated in terms of beyond the root end generally results in a poor
clinical normalcy (absence of symptoms) and prognosis. The impaired prognosis may result due
radiographic normalcy (reduction or disappearance of to over instrumentation and displacement of infected
radiolucency) associated with the tooth. These results debris into the periapical area.
are better stated and communicated in terms of healing b. Apical enlargement: It has been stated that a larger
as follows: apical preparation is associated with poor prognosis.
Healed: Follow-up reveals a combined clinical and Being technique sensitive, extensive apical
radiographic normalcy. enlargement is frequently associated with canal
transportation, jeopardising canal disinfection. But
Healing: Considering the fact that healing takes considering the importance of removing infected root
considerable time, it is described as a combination of dentin (harbouring intracanal micro-organism), an
clinical normalcy and reduced radiolucency. extensive apical preparation is believed to enhance
Functional: Follow-up reveals a residual radiolucency the disinfection, and favour improved prognosis.
combined with clinical normalcy. The residual Thus, apical enlargement, being technique sensitive,
radiolucency may have been either reduced or remain require considerable skill to achieve better results.
unchanged in size. c. Culturing: A negative culture obtained before root
The terms ‘healed’, ‘healing’ and ‘functional’ indicate filling may present better prognosis; however, the
the outcome of endodontic therapy; routinely used for technique is not followed in routine.
treatment success. d. Treatment sessions: The teeth treated in two sessions
or less have a better chance of healing than teeth
Factors of Prognosis treated in multiple sessions. It is established that teeth
treated at multiple visits are at a greater risk of
There are various preoperative, intraoperative and post- becoming infected with E. faecalis and developing
operative factors which influence the outcome of persistent apical periodontitis. Also, single visit root
endodontic therapy. canal treatment presents with a similar healing rate
as multiple visit treatment and patients experience
Preoperative Factors
less frequency of postobturation pain.
a. Tooth location: It has been observed that certain teeth e. Materials and technique:
(maxillary canines, maxillary second premolars and • Intracanal medicament: Teeth treated with calcium
mandibular canines) have a better prognosis than hydroxide heal better than teeth not medicated at
other teeth; however, any difference between anterior all or medicated with other material.
and posterior teeth has not been documented. • Instrumentation technique: Standardized technique
Maximum failure rate has been observed in gives better results than serial instrumentation
mandibular first premolar. technique.
b. Symptoms: Preoperative symptoms may be a f. Microbial elimination: Abundant use of sodium
reflection of the types and numbers of micro- hypochlorite, extensive apical enlargements and
organisms in root canal system. Nevertheless, the dressings with an effective intracanal medicament
healing rate is comparable for both symptomatic and such as calcium hydroxide provide maximal
asymptomatic teeth.
1 c. Size of the lesion: Smaller lesions up to 5.0 mm diameter
have shown better prognosis than the larger lesions.
microbial elimination. As micro-organisms are the
primary cause of persistent apical periodontitis;
microbial elimination significantly affects prognosis.

t.me/Dr_Mouayyad_AlbtousH
 Introduction to Endodontics 7

Postoperative Factors focal distance adapters are available, allowing for easier
Restoration: A well restored tooth that seals coronal adjustments during root canal procedures. Extendable
cavity effectively and prevents microbial ingress, (foldable) binoculars were introduced for better
favours a better prognosis. ergonomics. Magnetic arrest functions (clutch) are also
available for increased stability with use of microscope.
FUTURE OF ENDODONTICS LED lights (emission spectrum, 450–550 nm) offer a
significantly longer lifetime; however, brightness is
Endodontics is constantly evolving through improve- compromised as compared to xenon light.
ments in our understanding of the nuances of pulp
physiology and pathology, coupled with advances in
Root Canal Preparation
materials and other technological innovations. The
future of endodontics lies in exploring the different The concept of pericervical dentin (PCD) (defined as the
aspects of the principles of endodontics, facing the dentin near the alveolar crest; roughly 4.0 mm coronal to
challenges and taking the advantage of advancements the crestal bone and 4.0 mm apical to crestal bone), is a
in research and technology. critical structure and is crucial during transferring load
The important features are as follows. from the occlusal table to the root. The modification
in the traditional straight line access helps to preserve
Endodontic Imaging the pericervical dentin. With the modern endodontic
molar access, the coronal third of the crown can be
The advent of digital capture systems in the last couple
flared to gain access to the canal orifices instead of the
of years have revolutionized the endodontic diagnosis
straight line access. The Endoguide Burs (SS White)
and treatment
revolutionized the traditional access preparation
The advantages of digital imaging include significant
allowing shift from conservation to preservation.
dose reduction, relatively faster image acquisition,
Preserving the dentin thickness, right from the access
ability to enhance images, elimination of wet processing,
preparation to the root canal instrumentation is
easier transmission, and archival of images. The digital
considered mandatory for long-term success of
sensors are slightly smaller than film but sufficient for
treatment.
endodontic purposes.
The future of endodontic imaging relies on wireless Various rotary systems like Self-Adjusting File
sensors, including the newly introduced CMOS-APS System, V-Taper, Safe Siders, Hyflex Files, NeoNiTi,
sensors (in endodontics, instantaneous images are Protaper Next, Single File Systems (WaveOne, One
required, which is best served by CMOS sensors). Shape, Komet F360) have changed the sequence in
The advent of cone beam computed tomography endodontic instrumentation. Wizard Navigator is a
(CBCT) has resulted in widespread adoption of this newer file system, which the manufacturer claims to
technology for capturing three-dimensional image. face the endodontic canal challenges. Technologies and
CBCT is useful in diagnosing dental anomalies/ file design like the M-wire technology, controlled shape
developmental disturbances, anatomic variations, memory, hollow tube designs have great and direct
calcified canals, broken instruments, vertical root impact on the chemico-mechanical debridement. New
fractures, resorption (external and internal) etc. and devices are being designed in apex locator along with
especially useful in implant placement. the torque controlled gear reduction handpieces.

Endodontic Visualization Root Canal Disinfection

The use of optical magnification instruments enables The delivery of irrigant (irrigation dynamics) within
the endodontist to magnify a specified field, which is root canal system is crucial to achieve the requisite
usually difficult to perceive by the naked eye. The success in treatment. The mechanism by which fluid
recently introduced Endodontic Visualization System dynamics can be improved and also the development
(EVS) incorporates both endoscopy and orascopy into of newer-effective antimicrobials are under constant
one unit. The improved EVS II System combines the research.
fiber optic orascope and a rigid endoscope. EVS The improved delivery systems are Monoject
provides optimal magnification for visualization during endodontic needles, ProRinse probes, Micromega 1500,
endodontic procedures. CaviEndo systems, the Max-I-Probe, The Endo-Eze
A variety of additional upgrades for microscope
functions have been introduced. Instead of fixed focal
distances that limit the microscope to a certain distance,
system, etc. New irrigation technology will allow
clinicians to conveniently choose, dispense, and more
effectively irrigate root canal systems.
1

t.me/Dr_Mouayyad_AlbtousH
 8 Essentials of Endodontics

The use of ultrasonics along with dental operating BIBLIOGRAPHY

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t.me/Dr_Mouayyad_AlbtousH
Chapter
2
Biology of
Dentin–pulp Complex

Dentin is the mineralized connective tissue of the tooth

covered by enamel in coronal portion and cementum
in roots. The dental pulp is a loose specialized connec-
tive tissue in the central portion of the tooth, which is
enclosed on its outer surface by dentin. It comprises
cells, fibers, ground substance, blood vessels and
nerves. The pulp retains the vitality of dentin and dentin
provides the necessary support to pulp. The knowledge
of biology of these tissues is the basis of ‘restorative
dentistry’ and ‘preventive endodontics’. Since both the
tissues are inter-related, they are known as dentin–pulp
organ or dentin–pulp complex.
The functional grouping of pulp and dentin is
explained as follows:
• Pulp and dentin make physiological couple and Fig. 2.1 Low-power photomicrograph of the dentin–pulp
response collectively to external stimuli. complex of a tooth illustrating dentin, pulp, odontoblasts
• Pulp carries nerves; provides sensitivity to dentin. (arrow) and predentin (arrow)
• Pulpal connective tissues respond to dentinal
injuries, may not be directly stimulated. the other. The two tissues have a common embryonic
• Encapsulation in dentin creates a low compliance origin and also remain in an intimate relationship
environment that influences the defense potential of throughout the life of the vital tooth. When normal teeth
the pulp. are stimulated thermally, the dentinal fluid expands
or contracts causing hydrodynamic activation of
intradental nerves. Anything that influences dentin
STRUCTURE OF THE DENTIN–PULP COMPLEX affect the pulp and vice versa.
Dentin is composed of closely packed dentinal tubules If enamel and cementum are lost for any reason, pulp
containing dentinal fluid and the cytoplasmic processes and dentin become functionally continuous; dentin
of the cells (the odontoblasts). These most distinctive surface becomes a fluid filled continuum in such
cells of the dentin–pulp complex lie along the pre- conditions. This fluid medium along with micro-
dentin border forming the peripheral boundary of the organisms may diffuse across dentin to produce pulpal
dental pulp (Fig. 2.1). Under the odontoblasts, there is reactions. The pulp responds to the short term stimuli
cell-free zone and beneath that layer present a cell-rich by mounting an acute inflammatory response. In
zone. The pulp core with reduced cell density consists response to the long term stimuli, pulpal tissues
of connective tissue, blood vessels and nerves. The produce tertiary dentin as a biologic response in an
interdependence of dentin and pulp is responsible for attempt to reduce permeability of the dentin–pulp
dentin maturation and protection of tooth. complex. Thus, these two tissues function as an
Despite the differences in structure and composition, integrated unit. The concept that dentin–pulp complex
pulp and dentin are integrally connected; more so, the functions as an integrated unit is based on
physiologic and pathologic reactions in one tissue affect embryological and clinical evidences.

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 10 Essentials of Endodontics

DEVELOPMENT OF DENTIN–PULP COMPLEX

Tooth development, initiating at 6th week of intra-
uterine life, is a process characterized by a series of
sequential interactions between oral epithelium and the
underlying tissues. Dental epithelium provides
instructive signals for initiation of tooth development.
Under the influence of cell signals, epithelial cells of
the dental lamina at predetermined locations proliferate
and project into the underlying neural crest derived
ectomesenchyme. This projection gets pronounced in
to a cap shape due to proliferation of cells. Further
proliferation leads to the enamel organ assuming a bell
shape. Simultaneous with the proliferation, there also
occurs morpho-differentiation of the cells in the enamel Fig. 2.2a Longitudinal ground section of tooth illustrating
organ. The inner enamel epithelium differentiates into enamel, dentin and dentinoenamel junction (arrow)
specialized cells called ameloblasts, which lay down
enamel. The ectomesenchyme enclosed beneath enamel
organ condenses to form dental papilla whose outer-
most layer subjacent to inner enamel epithelium
differentiates into specialized cells called odontoblasts,
which lay down dentin. As dentin is laid down by
odontoblasts, the existing dental papilla matures into
dental pulp. Dental follicle is a mesenchymal tissue
surrounding the developing tooth germ. The inner and
outer epithelium grows apically to form a two cell
layers, called Hertwig’s epithelial root sheath, which
commences root formation and also determines the
shape of the roots. The Hertwig’s epithelial root sheath
signals adjacent mesenchyme of the dental papilla to
differentiate into odontoblasts, which lay down the root
dentin. Further, mesenchyme of the dental follicle Fig. 2.2b Dentinoenamel junction (arrow) in a ground
section. The scalloped nature of the junction when seen in
differentiates into cementoblasts, fibroblasts and
one plane is striking
osteoblasts.
During developmental processes, the growth i. Primary dentin: Primary dentin is the original tubular
factors/morphogens control the events, such as dentin largely formed prior to eruption of tooth. The
initiation, proliferation, morphogenesis, cyto- outer layer of primary dentin, called ‘mantle dentin’, is
differentiation and spatial distribution of cells. slightly less mineralized (about 4%) than regular
circumpulpal dentin. Mantle dentin is about 150 μ wide
DENTIN and comprises the first dentin laid down by newly
differentiated odontoblasts.
Dentin is the mineralized connective tissue of tooth. It
consists of apatite crystals, which act as filler particles ii. Secondary dentin: Secondary dentin is structurally
in a collagen matrix. This mineralized matrix was the same as primary dentin; however, secondary dentin
formed by odontoblasts, which began secreting collagen is formed after completion of root formation. The
at the dentinoenamel junction (Fig. 2.2a and b) and difference between secondary and primary dentin is
then grew centripetally while trailing odontoblastic that the secondary dentin is secreted slowly as
compared to primary dentin (Fig. 2.3a and b).
processes.
According to the formation, dentin is of three types: iii. Tertiary dentin: Tertiary dentin, known as ‘irritation
dentin’, is also known as reactionary, reparative or
i. Primary dentin

2 ii. Secondary dentin

iii. Tertiary dentin
irregular secondary dentin. It is formed only when
dentin has been subjected to trauma or irritation
(Fig. 2.4).

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 Biology of Dentin–pulp Complex 11

Chemical Composition
Dentin comprises 70% inorganic, 20% organic and 10%
water.
The inorganic phase is carbonate rich apatite crystals
of intertubular dentin. The apatite crystals are of small
size relative to large apatite crystals in enamel;
responsible for the high critical pH of dentin (pH 6.7).
The organic portion of dentin matrix is made up of
90% type I collagen and rest is non-collagenous
proteins, growth factors and proteoglycans.

Components of Dentin
i. Peritubular dentin: Dentin is traversed by 1.0–2.0 μ
Fig. 2.3a Section of dentin illustrating secondary dentin (*), diameter dentinal tubules. The dentinal tubules in the
dentin and pulpal space. The region where dentinal tubules coronal part of the tooth extend from the enamel to the
change direction delimits the junction between primary pulp and are 2.5 to 3.5 mm long. They contain
and secondary dentin odontoblastic processes and tissue fluid. The tubules
have a highly mineralized lining, along most of their
length known as the peritubular dentin. The peritubular
dentin is formed as a main part of coronal circumpulpal
dentin. It is not found in the most pulpal part of dentin
in newly erupted teeth. This feature is important in
restorative dentistry because the main part of deeply
prepared tooth in young individual will comprise
cytoplasmic material rather than mineralized dentin
matrix.
The continuous growth of the peritubular dentin in
the main bulk of dentin leads to obturation of the
tubules. Occluded dentinal tubules are referred to as
‘dentin sclerosis’. Sclerosed dentin reacts differently to
acid etching than normal dentin; causes differences in
the collagen mesh when exposed to acid etching. The
Fig. 2.3b Obliteration of pulpal space (*) by deposition of
etching time may have to be modified to provide an
secondary dentin
adequate hybrid layer of collagen and resin. Dead tracts
are also seen in dentin. These are the dentinal tubules
in which odontoblasts degenerate either due to caries,
trauma or injury during cavity preparation. Under
transmitted illumination, the tracts appear dark because
air in them refracts the light (Fig. 2.5).
ii. Intertubular dentin: Intertubular dentin (50 to 60 nm
long, 36.4 + 1.5 nm wide and 10.3 + 0.3 nm thick) is the
dentin presents in between the dentinal tubules. It is
less mineralized than peritubular dentin and can be
easily distinguished. Intertubular dentin matrix has a
dense collagen matrix; whereas, peritubular dentin
matrix contains little collagen. The mineral of
peritubular dentin is in the form of carbonate rich
hydroxyapatite crystals, having higher crystallinity and
Fig. 2.4 Tertiary (reparative) dentin with a regular tubular are harder than intertubular dentin.
pattern and no cellular inclusions. This dentin probably was
deposited slowly in response to a mild stimulus. (1) Tertiary
(reparative) dentin; (2) Secondary dentin
iii. Odontoblasts: Odontoblasts form a single layer of
cells between dentin and pulp; their number may vary
2

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 12 Essentials of Endodontics

that penetrates into mineralized dentin, falling the

lumen of dentinal tubules. The odontoblastic process
lacks cell organelle, but contains secretory vacuoles and
microtubules. Its diameter is 3–4 μ at the pulp predentin
border and gradually narrows as it passes within the
dentinal tubules.
The depth of penetration of cytoplasmic processes
is controversial. Various studies have observed
different depth of penetration. It is hypothesized that
in developing young teeth, the processes might be up
to dentin-enamel junction, while in other teeth, the
processes may only penetrate up to 0.3 mm into coronal
dentin (may be slightly more in root dentin).
It is hypothesized that the cytoplasmic process
extends about one-third of the distance from predentin
Fig. 2.5 Dead tracts in a ground section of a tooth. Under
transmitted illumination the tracts appear dark because
to enamel, indicating that vital tissue changes occur
air in them refracts the light only in the inner-third coronal dentin towards pulp.
Changes occurring in the outer two-thirds of the dentin
from 45000–55000 cells/mm 2 . The cell body of may be of physiochemical nature by precipitation of
odontoblasts is located on the pulp side of dentin and mineral salts within the tubules or growth of the
cytoplasmic processes are inserted into tubules of peritubular dentin via components secreted into the
mineralized dentin. A large nucleus is located in the periodontoblastic space. These components may
basal portion of the cell, close to the pulp along with diffuse peripherally to form a matrix that will
Golgi apparatus, mitochondria and endoplasmic mineralize.
reticulum. The cell body is 20–40 μ tall and 3.0–5.0 μ
v. Dentinal fluid: It has been hypothesized that a
wide, depending upon the dentinogenic activity. They
transport mechanism exists between blood circulation
produce the organic matrix of pre-dentin and dentin
and dentin. It is suggested that odontoblasts regulate
including Type I collagen and proteoglycans.
the transport of substances into dentin. Dentin contains
Odontoblasts intracellularly transport calcium ions to
several serum proteins, mainly in dentinal tubules. The
the mineralization front, and have the capacity to
origin of the fluid in dentinal tubules (either from pulp
degrade organic matrix.
tissue extracellular space or from blood vessel or both)
The cytoplasmic feature of the odontoblasts varies may not be clear, but the fluid present, containing
according to the functional activity of the cell. inorganic and organic constituents, is a significant
Odontoblasts have all the characteristic organelles, component of pulp-dentin complex. The space between
which are associated with protein and proteoglycans odontoblast process and the tubule wall is filled with
production. The activity of odontoblasts is reflected in fluid, commonly referred to as ‘dentinal fluid’. The
the number and types of organelles present in the dentinal fluid is under control of odontoblasts, until
cytoplasm. tissue is damaged because of caries, cavity preparation,
The adjacent odontoblasts are attached together with etc. It is established that the odontoblastic cell layer
extension junctional complexes and with gap junction. forms a functional barrier that restrains the passage of
The junctional complex consists of tight junction, fluid, ions and other molecules along the extracellular
known as zonula occludens. These tight junctions are pathway.
thought to contribute in the final polarization of It has been accepted that dentin sensitivity to
odontoblasts. Unlike other polarized cells, e.g. epithelial extrinsic irritants is mediated through alteration in
cells, the tight junctions in odontoblasts may be related hydraulic conductance of the dentinal fluid. The
to cell differentiation than to permeability of cell layers. accepted hydrodynamic theory implicate fluid
The interodontoblastic collagen fibers (von Korff’s movement through dentinal tubules as a transducing
fibers) may pass through the odontoblast-predentin mechanism, explaining dentin sensitivity (dentin is
layer from pulp into dentin. more sensitive to outward than inward flow).
2 iv. Odontoblastic processes: The odontoblastic processes
are the cytoplasmic extension, gradually narrowing,
Adhesive restorations are also dependent on the
dentinal fluid. Increased dentinal wetness and fluid

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 Biology of Dentin–pulp Complex 13

flow make successful bonding more difficult in deep Dentin Permeability

cavities than superficial dentin. Dentinal fluid The tubular structure of the dentin provides channels
movement is also affected by other extrinsic factors. A for the passage of solutes and solvents across dentin.
high sucrose diet may depress dentinal fluid flow. The number of dentinal tubules per square millimeter
Numerous studies have demonstrated that high sucrose varies from 15,000 at dentinoenamel junction to 65,000
diet reduce dentin formation during dentinogenesis. at the pulpal end. The density and the diameter of the
The dentinal fluid flow plays a protective role against tubules increase with dentin depth from the
bacterial acidogenic challenge. dentinoenamel junction to pulp. The permeability of
Caries does affect dentinal fluid. In carious teeth, dentin is lowest at dentinoenamel junction and highest
dentinal fluid act as a protective factor through the at the pulpal end.
occlusion of dentinal tubules and the innate response Dentin permeability depends on following factors:
of the dentin–pulp complex to the deposition of i. Movement of inorganic/organic substances
intratubular immunoglobulins [fluid may contain through dentinal tubules
superoxide dismutase 3 (SOD3), considered to be ii. Movements of exogenous substances into the
present in lymph and plasma]. The presence of ‘SOD3’ intertubular dentin
and the higher concentration of ‘Fetuin A’ in dentin as Dentin may be regarded both as barrier and as a
compared to serum indicate that the active transport permeable structure, depending on its thickness, age
system by the odontoblasts are involved for the serum and amount of inorganic materials. The rate of diffusion
proteins. The overall permeability of dentin depends of exogenous material across the dentin to the pulp is
upon the integrity of the odontoblastic layer, presence dependent upon dentin thickness and the hydraulic
of odontoblastic processes in dentinal tubules and the conductance of dentin. Thin dentin permits more
flow rate/viscosity of dentinal fluid. diffusion than thick dentin. It is established that the
inward diffusion of materials competes with the
Response of Odontoblasts to Injury outward fluid movement in exposed vital dentin (open
Depending on the nature, magnitude and duration of tubules). This competition may serve as a protective
the injury, the odontoblasts may be reversibly or function mitigating the flow of bacterial products into
irreversibly damaged. Irreversible injury to odontoblast exposed dentin.
may occur during cavity preparation or desiccation of The permeability of the dentin varies widely. Axial
exposed dentin surface. dentin is more permeable than occlusal dentin. The
New dentin may eventually laid down on the gingival floor/gingival extension of the finish lines in
dentinal wall corresponding to the site of injury by the tooth preparation are often considered as high dentin
action of secondary odontoblasts which are differen- permeability regions. The permeability of sclerotic
tiated from undifferentiated mesenchymal cells present dentin is very low.
in the pulp. The new dentin formed in response to an The permeability of root dentin and coronal dentin
is not uniform. The root dentin has a permeability about
injury is called ‘tertiary dentin’. When tertiary dentin is
3.0 to 8.0% as that of coronal dentin. It is likely that the
formed by newly differentiated odontoblasts, it is
relative impermeability of root dentin protects the
known as ‘reparative dentin’ and when tertiary dentin
periodontal tissues from wide variety of potentially
is formed by the surviving odontoblasts, it is known as
cytotoxic compounds that might be used as intracanal
‘reactionary dentin’. Tertiary dentin formation medicaments.
irrespective of type represents an important defense
The permeability of root dentin itself is not uniform
mechanism and a regenerative property of the pulp- but displays regional differences along its axial length.
dentin organ. The dentin formed locally may vary in Cervical and middle root dentin has higher permea-
structure and composition. The tubules are often more bility than apical dentin. The permeability of the floor
irregular, the dentin is less mineralized and it may have of pulp chamber in the region of furcation is also high
higher content of organic material than primary dentin. because of presence of accessory canals in the furcation
Interface dentin, often a tubular dentin forms a barrier area.
between the physiologic secondary dentin and tertiary Dentin permeability has numerous clinical implica-
dentin. This barrier reduces the permeability of the tions. The dentin disks when soaked in 5.0% sodium
affected dentin and may make it impermeable because
the tubules from primary dentin do not cross the
interface dentin.
hypochlorite solution for one hour produces 105%
increase in hydraulic conductance of dentin (important
during irrigation). During endodontic instrumentation
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 14 Essentials of Endodontics

of root canals, the softest inner dentin is removed. The and smear plugs prevents the entry of sealer or even
increase in diameter of the root canal, facilitates thermoplasticized gutta-percha into the dentinal tubules.
thinning of dentin and decreasing the number of the
tubules/mm. This may increase the permeability; PULP
however, preparation of root canal also creates smear Dental pulp is specialized, highly vascularized
plugs and smear layers on the dentinal surface that connective tissue and is in direct communication with
decreases its permeability. periodontium through apical foramen. Pulp is
The tubule density near the apical dentin is of great incompressible; volume within pulp cannot be
importance during apical surgery. During apical increased (during inflammation, tissue pressure is
surgery, resection of the root at an oblique angle may increased rather the volume). Pulp has the unique
be favoured to facilitate visibility and placement of a ability to form dentin even after the tooth is fully
reverse filling. But this angled resection may expose developed. The pulp is relatively rich source of stem
dentinal tubules beneath the retrofilling material, cells.
subsequently more chances of leakage. The greater the
The pulp is divided into four zones (Fig. 2.6a and b).
angle of resection, the greater the potential for
microleakage. Thus, minimal angled sections have been
advocated to prevent leakage through exposed dentinal
tubules.
Smear Layer and Smear Plugs
Smear plugs are composed of ground debris, whose
particle size is smaller than the tubule orifice. The pre-
sence of ground debris in the tubule orifice lowers the
permeability of dentin. It is pertinent to note that sodium
hypochlorite does not remove the smear layer because
it contains both organic component and inorganic
component (sodium hypochlorite removes organic
component). Only after removal of inorganic compo-
nent with ethylenediaminetetraacetic acid (EDTA) or
acids, sodium hypochlorite can remove the organic
portion. This is why sodium hypochlorite and EDTA
in combination are preferred as endodontic irrigants. Fig. 2.6a Micropictograph of pulp organ illustrating (1) pre-
Any instrument placed in contact with the root canal dentin; (2) odontoblast layer; (3) cell free zone and (4) cell
will create a smear layer. The presence of the smear layer rich zone

2 Fig. 2.6b Zones of pulp (diagrammatic)

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 Biology of Dentin–pulp Complex 15

i. Zone of odontoblasts: A layer of odontoblasts, pulp tissue is facilitated when the broach is passively
circumscribes the outermost part of the pulp. They form placed apically engaging these collagen bundles.
a single layer lining in the most peripheral portion of The ground substance in pulp, the extracellular
the pulp. The cytoplasmic extension (odontoblastic matrix, is consisted of polysaccharides, glycoproteins
process) extends into dentinal tubules. The shape of the and proteoglycans. The proteins bind to cell surfaces
cell body of odontoblasts is not uniform, rather these and other matrix molecules. The water content is
cells are tall and columnar in the coronal pulp, short approximately 90%, which may decrease in aged pulp.
and columnar in the mid portion of the tooth and The blood vessels and nerves are embedded in the
cuboidal to flat in root portion. The primary function of pulp matrix in the central portion of pulp, emanating
odontoblasts is to produce and deposit dentin. branching to the periphery of the pulp. The nerve fibers
enter through the apical foramen; whereas, lymphatics
ii. Zone of Weil (cell-free zone): Subjacent to odontoblast
and venules exit the pulp mainly through apical
layer, an area relatively free of cells, known as ‘cell-
foramen.
free zone’ or ‘zone of Weil’ is seen. Major constituents
of this zone are the rich network of mostly Components of Pulp
unmyelinated nerve fibers, blood capillaries and few
fibroblasts. The function of capillaries is to provide a. Cells
nutrition to the odontoblasts, especially during The main cells of pulp are:
dentinogenesis; the nerve plexus are involved in the
neural sensation of pulp. i. Odontoblasts: Odontoblasts are also part of pulp; the
highly differentiated cells of the pulp. The cell body of
iii. Cell-rich zone: Next is the cell-rich zone. The consti- odontoblasts is located on the pulp side of dentin and
tuents of this zone are ground substance, fibroblasts, cytoplasmic processes are inserted into tubules of
undifferentiated mesenchymal cells, defense cells mineralized dentin. The cell structure of odontoblasts
(macrophages and lymphocytes), blood capillaries and is described under ‘components of dentin’.
nerves. The higher density of fibroblasts in this zone is
ii. Fibroblasts: These are the most numerous connective
much more prominent in the coronal pulp than in root
tissue cells with the capacity to synthesize and maintain
pulp. The functions of cell-rich zone are:
connective tissue matrix. Synthesis of collagen is a main
• Fibroblasts form as well as degenerate collagen fibers
function of fibroblasts in the pulp. Fibroblasts are also
• By depositing calcified tissues, they help in responsible for synthesis and secretion of a wide range
reparative dentin formation of non-collagenous extracellular matrix components
• Collagen fibers secreted by odontoblasts form the such as proteoglycans and glycoproteins (fibronectin).
dentinal matrix; whereas; collagen fibers secreted by In addition to synthetic activity, fibroblasts are also
fibroblasts support the pulp. involved in the degradation of extracellular matrix.
• Ground substance acts as barrier against the spread Fibroblasts are able to phagocytose collagen fibrils and
of bacteria. It acts as transport medium for digest them intracellularly by lysosomal enzymes.
metabolites and other waste products.
iii. Undifferentiated mesenchymal cells: These are
• Collagen fibers collectively protect the neurovascular distributed throughout the cell-rich zone occupying the
bundle, especially in the apical third area. perivascular area. These cells appear as stellate shaped
• Undifferentiated mesenchymal cells may differen- cells with a relatively high nucleus to cytoplasmic ratio.
tiate into other cells during repair and regeneration, When stimulated, they may give rise to fibroblasts or
as per need. odontoblasts as per need (also known as reserve cells).
iv. Pulp proper: From the cell-rich zone inward is the In older pulps, the number of undifferentiated
central connective tissue mass known as pulp proper. mesenchymal cells may diminish, which reduces the
This zone contains fibroblasts, larger blood vessels and regenerative potential of pulp.
nerves. Undifferentiated mesenchymal cells and iv. Immunocompetent cells: The ability of connective
defense cells such as macrophages are frequently tissue to generate local inflammatory and immune
located in perivascular area. Collagen fiber bundles are reactions makes it an active participant in host defense.
more numerous in root pulp than coronal pulp. This capacity depends on immune-competent cells,
The clinical implication of this higher density of
collagen fiber bundles in apical region is the use of
barbed broach during removal of pulp. The removal of
which include lymphocyte, macrophages and dendritic
cells. They increase in number during inflammation and
may play role in repair process in the pulp.
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 16 Essentials of Endodontics

b. Vascularity of Pulp dependent on the hydraulic conductance of the dentinal

The most restrictive anatomic characteristic of the pulp fluid.
is that it is encased in rigid mineralized tissue. This
d. Nerve Impulses in Pulp
provides the pulp, a low-compliance environment in
which nutrition for the tissue is almost entirely supplied Myelinated and unmyelinated nerves enter the pulp
via vessels traversing the narrow apical foramen. through apical foramen and through accessory canals.
It is clinically important to recognize that many of They mainly follow the blood vessels as they branch
the capillaries in the pulp are largely non-functional in and form a network of terminal endings in the
the normal pulp. The blood flow to specific areas can odontoblastic–subodontoblastic region and in the peri-
be increased quickly because of capillaries, i.e. local and odontoblastic spaces of dentin tubules.
general hyperaemia in the pulp can occur almost Myelinated A fibers (A-β and A-δ fibers: Ratio is
instantaneously without requiring the ingrowth of the 10:90) and non-myelinated C-fibers constitute the
new capillaries. sympathetic nervous system. Both sensory and
Arterioles enter and venules and lymphatics leave sympathetic nerve endings may terminate in the
dental pulp through the apical foramen. Vessels also walls of the blood vessels in main pulp. They are
enter and leave the pulp via accessory lateral canals, activated at an early stage in the inflammatory process
which may be located anywhere on the root, but are and initiate vasodilation, which starts the protective
most commonly found in the apical region. Relatively response to injury by increasing blood volume and
large arterioles pass through the root pulp to supply vascular permeability in the affected area. A number
the coronal pulp. They branch and terminate as of neuroreactive peptides has been demonstrated in the
capillaries, which are particularly abundant in the pulpal nerve endings, including neurokinins, substance
coronal subodontoblastic region. P and calcitonin generelated peptide. Both sympathetic
The structure of blood vessels in the pulp is basically nerve fibers and sensory nerve fibers have effects on
similar to the other blood vessels of body; the blood pulpal circulation. The number of nerve fibers and the
vessels in pulp are thin walled as compared to the size associated neuropeptides decrease with age, which
of lumen. The structural characteristics include explains the reduced sensitivity of teeth in adults and
discontinuities in the endothelial walls and fenestration older individuals.
of capillaries. They facilitate the exchange of nutrients It has been suggested that some nerve fibers that
and waste products between the interstitial tissue fluid terminate in the dentinal tubules may be branches of
and blood plasma. This exchange is particularly the same nerves that terminate in the wall of blood
important at the time of injury, trauma and carious vessels. This phenomenon explains the difficulties in
lesions affecting the pulp and plays an important role localizing pulpal pain.
in maintaining the fluid balance. Nerve activity in the pulp can be modified by
The arterial supply of pulp is from posterior–superior anesthetic solutions and epinephrine, which may
alveolar arteries, infraorbital arteries and inferior decrease the releases of neuropeptides. Eugenol, known
alveolar branch of maxillary arteries. Pulp does not for its sedative effect on pulpal pain has been shown to
have a collateral blood supply. Coronal pulp has nearly have an inhibitory effect on sensory nerve action.
twice the capillary blood flow than the root pulp Sensory innervation of pulp through trigeminal
(maximum capillaries are in pulp horns). The arterio- ganglion is by means of maxillary nerve and the
vascular anastomosis connects the arterioles directly mandibular nerve. A-fibers transmit fast pain (sharp,
to venules, bypassing the capillary bed (small 10 piercing) and C-fibers transmit slow pain (dull, aching).
vessels). They play a vital role in regulation of blood A- fibers get stimulated first during electric pup testing,
flow. followed by C-fiber, if the intensity of stimulus is
increased.
c. Interstitial Fluid Pressure
The interstitial fluid pressure in the pulp is relatively Pulp–Dentin Complex Regeneration: Biological Cues
high and it plays a role in sudden pain experience when The pulp–dentin complex plays a key role in the
cavity preparation reaches unaffected dentin. The immune defense against the external stimuli and
exposure of dentin causes sudden movement of the stimulate tissue repair during infection or trauma. The

2 contents of the tubules, leading to the activation of

nerves adjacent to the odontoblasts and resulting in
pain. The fluid flow from the pulp to exposed dentin is
unique anatomic and physiologic nature of pulp–dentin
complex makes it a difficult tissue to regenerate. The
outcome of regenerative endodontic cases reflect only

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 Biology of Dentin–pulp Complex 17

the ectopic tissue formation in the root canal space. The controlled release of growth factors are useful in
formation of fibrous connective tissue in the root canal diverting cellular events towards regenerative rather
space has been documented. The successful regenera- than repair in regenerative endodontic treatment.
tive procedures have resulted in excellent healing of
periapical tissues, increased root lengths and to some
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canal space along with stem cells or progenitor cells, 7. Goldberg M and Septier D. Phospholipids in amelogenesis
because blood clot contains growth factors like TGF-β, and dentinogenesis. Crit. Rev. Oral Biol. Med.:2002; 13:
PDGF and IGF, etc. These factors activate the cells and 276–290.
help regeneration of pulp-dentin complex. 8. Goldberg M and Smith AJ. Cells and extracellular matrices
The exogenous biological cues are as good as of dentin and pulp: a biological basis for repair and tissue
endogenous cues. A few exogenous biological cues with engineering. Crit. Rev. Oral Biol. Med.: 2004; 15:13–27.
higher concentration, e.g. plasma rich platelet, may 9. Gong T, Heng BC, Lo EC and Zhang C. Current advance and
future prospects of tissue engineering approach to dentin/
augment the regeneration process (PRP has higher
pulp regenerative therapy. Stem Cells Int.: 2016; ID9204574.
concentration of blood-derived factors as compared to
10. Goracci G. Mori G. and Baldi M. Terminal end of the
apical bleeding). odontoblast process: a study using SEM and confocal
The biological molecules involved in cell differentia- microscopy. Clin. Oral Investig.: 1999; 3:126–132.
tion and tissue formation should have controlled 11. Grayson W and Marshall J. Dentin: Microstructure and
release, so that sustained biological effects can be characterization. Quintessence Int.: 1993; 24:606–617.
achieved, especially during later stage of regeneration. 12. Hahn CL and Best AM. The pulpal origin of immunoglobulins
The biological molecules involved in cell migration in dentin beneath caries: an immunohistochemical study. J.
Endod.: 2006; 32:178–182.
are not very critical as their role is limited in the initial
13. Henry B and Trowbridge O. Pulp Biology: Progress during
phase of regeneration (controlled release is referred to
the past 25 years. Aust. Endod. J.: 2003; 29:5–12.
as the release of biological factors as a specific rate in a 14. Heyeraas KJ. And Berggreen E. Interstitial fluid pressure in
given period of time). It has been established that at normal and inflamed pulps. Crit. Rev. Oral Biol. Med.: 1999;
the early stage of regeneration, cell mobilization is 10:328–336.
predominant; whereas, in the later stage cell differentia- 15. Holland GR. The odontoblast process: Form and function. J.
tion and tissue formation are predominant. Dent. Res.: 1985; 64:499–514.
The biological factors released from dentin or evoked 16. Howard C, Murray PE and Namerow KN. Dental pulp stem
bleeding usually have high initial burst followed by call migration. J. Endod.: 2010; 3:1963–1966.
rapid decrease in delivery. These may not be available 17. Ishizaka R, Lohara K and Murakami M. Regeneration of dental
pulp following pulpectomy by fractionated stem/progenitor
at the later stage of regeneration when tissue differentia-
cells from bone marrow and adipose tissue. Biomaterials:
tion and tissue formation are to take place; subsequently, 2012; 33:2109–2118.
leading to ectopic tissue formation in the root canal 18. Jang JH, Lee W, Cho KM, Shin HW, Kang MK Park SH and
spaces. The delivery of biological molecules requires a
scaffold or a carrier that allows controlled release of
the molecules. The biodegradable scaffold allowing
Kim E. In vitro characterization of human dental pulp stem
cells isolated by three different methods. Resto Dent Endod.:
2016, 41:283–295.
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19. Jontell M, Okiji T, Dahlgren U and Bergenholtz G. Immune 29. Roberts-Clark DJ and Smith AJ. Angiogenic growth factors in
defense mechanism of the dental pulp. Crit. Rev. Oral Biol. human dentine matrix. Arch. Oral Biol.: 2000; 45:1013–1016.
Med.: 1998; 9:179–200. 30. Simon SR, Berdal A, Cooper PR, Lumley PJ, Tomson PL and
20. Kim G. Biological molecules for the regeneration of the pulp- Smith AJ. Dentin–pulp complex regeneration: from lab to
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21. Kinney JH, Nalla RK, Peple JA, Breunig TM and Ritchie RO. 31. Smith AJ, Duncan HF and Diogenes A. Exploiting the
Age related transparent root dentin: Mineral concentration, bioactive properties of the dentin–pulp complex in
crystallite size and mechanical properties. Biomaterials: 2005; regenerative endodontics. J. Endod.: 2016; 42:47–56.
26:3363–3376. 32. Smith AJ, Murray PE, Sloan AJ, Matthews JB and Zhao S. Trans-
22. Magloire H, Maurin JC, Couble ML, Shibukawa Y, Tsumura dentinal stimulation of tertiary dentinogenesis. Adv. Dent.
M, Thivichon-Prince B and Bleicher F. Topical review. Dental Res.: 2001; 15:51–54.
pain and ondotoblasts: facts and hypotheses. J. Orofac. Pain: 33. Smith JA. Vitality of the dentin pulp complex in health and
2010; 24:335–349. disease: Growth factors as key mediators. J. Dent. Educ.: 2003;
23. Mjor IA, Sveen OB and Keyeraas KJ. Pulp dentin biology in 67:678–689.
restorative dentistry. Part I: normal structure and physiology. 34. Tjaderhane L and Haapasalo M. The dentin–pulp border: a
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pulp reactions and adhesive technology. Braz. Dent. J.: 2009; 35. Tjaderhane L, Marcela RC, Breschi L, Tay FR and Pashley
20:3–16. DH. Dentin basic structure and composition—an overview.
25. Morotomi T, Tabata Y and Kitamura C. Dentin–pulp complex Endod. Topics: 2012; 20:3–29.
regeneration therapy following pulp amputation. Adv. Tech. 36. Tziafas D. Belibasakis G, Veis A and Papadimitriou S. Dentin
Biol. Med.: 2015; 3:1–5. regeneration in vital pulp therapy: design principles. Adv.
26. Ninomiya M, Ohishi M, Kido J, Ohsaki Y and Nagata T. Dent. Res.: 2001; 15:96–100.
Osteopontin in human pulp stones. J. Endod.: 2001; 27:269– 37. Tziafas D. Dentinogenic potential of the dental pulp: facts
272. and hypotheses. Endod. Topics: 2010; 17:42–64.
27. Pashley DH. Dentin-predentin complex and its permeability: 38. Tziafas D. The future role of a molecular approach to pulp-
physiologic overview. J. Dent. Res.: 1985; 64:613–620. dentinal regeneration. Caries Res.: 2004; 38:314–320.
28. Pietrzak WS and Eppley BL. Platelet rich plasma: biology 39. Zhu X, Zhang C and Huang GT. Transplantation of dental
and new technology. J. Craniofac. Surg.: 2005; 16:1043– pulp stem cells and platelet-rich plasma for pulp regeneration.
1054. J. Endod.: 2012; 38:1604–1609.

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Chapter
3
Pathophysiology of Pain

Pain is unpleasant, sensational, subjective-emotional Reversible pulpitis require conservative treatment;

experience associated with actual or potential tissue whereas, irreversible pulpitis and/or pulp necrosis
damage. It has the function of a warning to tissue need root canal treatment.
damage and also activates the defense mechanism in
order to prevent further damage. Pain is not a disease; a. Reversible Pulpitis
additional manifestations may be fear, anxiety, pupil A pulp with reversible pulpitis, has mild inflammation
dilatation, nausea, vomiting, tachycardia etc. Pain and is capable of healing once the irritating stimulus is
perception is also not constant; varies considerably with removed. Pain is only felt when a stimulus (usually cold
environmental conditions. The most common reason or sweet foods but sometimes heat) is applied to the
for patients to visit dental clinic is pain, which may tooth, and the pain ceases within a few seconds or
originate from tooth and associated tissues or may be immediately upon removal of the stimulus. The pain
other non-odontogenic reasons. Thorough anamnesis is short and sharp in nature but not spontaneous. There
(recalling the past events) is important to know the are no significant radiographic changes in the periapical
history of pain, its frequency and periodicity, etc. region (radiographic findings may be the cause of the
Anamnesis should be complimented with clinical problem, such as caries, a deep restoration, etc.). The
examination and relevant tests, as need be, to reach out pulp’s response to cold or heat is exaggerated and brief.
at proper diagnosis. Pain in orofacial region can be Brannstrom described the hydrodynamic theory in
odontogenic or of non-odontogenic reasons. which the pathophysiology of dentin sensitivity is
related to the sudden rapid movement of fluid into and
ODONTOGENIC PAIN out of the dentinal tubules as a reaction to certain
stimulants. According to this theory, acute pain
Odontogenic pain has its source from pulp-dentin develops when fluid movement activates A-delta fibers
complex and/or periapical tissues (mainly endodontic). in the vicinity of pulp-dentin junction. These symptoms
It may be because of preendodontic, interappointment are resolved by removing the cause. The mild trauma/
or postendodontic reasons. The causes and effective stimulus can cause mild inflammation and sufficient
management of pain encountered at different stages of mechanical damage to stimulate a nerve reaction;
endodontic treatment are described. subsequently causing exaggerated response to vitality
tests, indicating severe inflammation. This state of pulp
A. Pre-endodontic Pain is called reversible as inflammation is mild and limited
The situations arising prior to the removal of the pulp to the area of A-delta nerves; if further infection is
are designated as pre-endodontic pain. Such kind of prevented, normal state of pulp can be achieved.
pain is caused by reparable or irreparable pulpal Dental caries is the most frequent cause of pulpitis.
diseases with or without periapical tissue involvement. As caries progresses, the pulp undergoes changes from
90% patients seeking dental treatment are suffering hyperaemia to pulpitis, and frequently to necrosis. The
from pain originating from either pulpal or periapical mechanism by which caries induces pulpitis is probably
region (10% may be periodontal or non-odontogenic a combination of direct toxic effects on the pulp and
pain). Based on treatment, pulpal pain can be either indirect immune reactions (antigen-antibody cellular
from reversible pulpitis or irreversible pulpitis types). As the lesion progresses, it causes opening of
(advanced stages may present as pulp necrosis). dentinal tubules, subsequently increasing dentin

19

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 20 Essentials of Endodontics

permeability. The increased permeability allows the canal. The relief with cold water is temporary and
odontoblasts to get affected by toxic bacterial products. the pain returns as soon as the tooth warms up and the
The early inflammatory reaction is containment of gases expand. It is hypothesized that the apical part of
bacterial growth within the pulp due to phagocytosis the pulp nerves are the last to necrose.
by neutrophils but at the expense of pulp tissue. At this When the carious lesion penetrates through the
stage, since the carious lesion has not penetrated into dentin and contacts the pulp, the nature of
the pulp, removal and restoration of the lesion will inflammatory response changes from a collection of
allow the pulp to heal. Certain chemical mediators mostly mononuclear leukocytes to a localized collection
(bradykinin, serotonin and substance P) sensitize the of polymorphonuclear leukocytes forming micro-
A-delta fibers and lower their threshold, thereby abscesses within the chronic inflammatory lesion. It is
increasing their response to stimulants. at this stage that reversible pulpitis becomes irreversible.
It is established that the inflammatory mediators, Eventually, initial microabscess leads to numerous
capable of causing pain, are released in the pulp in other microabscesses. When they are large enough to
direct proportion to the insult. Serotonin (5 HT), able coalesce, the pulp undergoes liquefaction necrosis.
to sensitize intra-dental A fibers and Bradykinin have A few authors suggested that inflammation alone
shown to be in significant higher concentration in would not cause pulp death. The injured pulp often
irreversibly inflamed human pulps. It has also been becomes necrotic even when the injury is minor and
demonstrated that neuropeptides from the nociceptive intrapulpal pressure rises very high (up to 80 mm Hg).
nerve fibers present in the pulp [calcitonin gene-related Others opined that the pulp pressure rises initially after
peptide (CGRP), Neurokinin A and substance P] are injury but declines to its normal level and the pulp may
found in significantly higher concentrations in recover.
symptomatic pulp compared with healthy pulps. Sharp The increase in pain from inflamed pulps at night or
pain due to external stimulus like cold which gets the transformation of the pain from a dull to a throbbing
relieved after the stimulus is removed, is associated ache has rational physiologic bases. The reduced
with the pulpodentinal myelinated A-delta neurofibres. pressure effect occurs as the head in normal upright
posture, is above the heart (gravity keeps the pressure
b. Irreversible Pulpitis low). When the patient lies down, the gravitational
The classic symptom of irreversible pulpitis is lingering effect disappears, significantly increasing the pulp
pain induced by thermal stimuli. Even mild tempera- pressure, over and above that caused by endogenous
ture changes (tap water, breathing cold air) may induce mediators of inflammation. In the supine position, a
pain. The initial reaction is a very sharp pain to hot or higher tissue pressure develops in the pulp, which
cold stimuli, which lingers for a couple of minutes to causes more pain. Another factor contributing to
hours even after the stimulus is removed. The lingering elevated pulp pressure on reclining is the effect of
pain is usually a dull ache or a throbbing pain. posture on the activity of the sympathetic nervous
Spontaneous (unprovoked) pain, which may wake the system. When a person is upright, the baroreceptors
patient at night and may become worse when lying (the so-called “carotid” sinus), located in the arch of
down, is another hallmark feature of irreversible the aorta and the bifurcation of the carotid arteries,
pulpitis. The more C-fiber-mediated pain (dull, throbbing, maintain a relatively high degree of sympathetic
poorly localized), the more severe the inflammation and stimulation to organs richly innervated by the
more likely to be irreversible in nature. Patients with sympathetic nervous system.
irreversible pulpitis may have difficulty locating the Irreversible pulpitis is difficult to diagnose until
precise tooth (source of pain). They may even confuse periradicular tissues are involved. As the periradicular
the maxillary and mandibular arches (but not the left tissues get involved, the tooth becomes sensitive to
and right sides of the mouth) because of the extensive percussion and the affected tooth can be identified.
branching of dental nerve axons and perhaps fewer
proprioceptive fibres in the pulp. c. Pulp Necrosis
Patients may complain of a dull continuous pain, The pulp inflammation leads to necrosis followed by
exacerbated by heat but relieved by cold. Exact infection and eventually loss of tissue because of its
mechanism is not clear; however, it is speculated that ingestion by bacteria. It has been reported that in

3 micro-organisms in the infected pulp produce gases,

which contract with cold water, relieving pressure on
the nerve endings, particularly in the apical portion of
50–60% cases, pulps can progress from vitality to
necrosis without pain. This phenomenon has been
termed as ‘painless pulpitis’. It is not known how

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 Pathophysiology of Pain 21

asymptomatic pulp death can happen; one hypothesis The clinical findings of pulpitis to periradicular
is that the progress of inflammation is so rapid that inflammation are sensitivity to bite and dull-persisting-
there is no pain or conversely the inflammation is so pulsating pain. As the inflammatory process progresses
slow that the classical inflammatory mediators that to alveolar bone, the patient may report fever, swelling,
participate in the pain process never reach a critical etc. The inflammation progressing to periosteum is the
level. It has also been suggested that there may be most painful phase.
effective modification by local as well as centrally Chronic apical periodontitis represents a dynamic
mediated systems present in pulp (endogenous opioid balance between exogenous root canal microbiota and
and adrenergic sympathetic systems do exist in the pulp their by-products, and the host’s defense mechanisms.
which may inhibit pulpal pain activation). The effects The chronic lesion, termed as ‘periapical granuloma’,
of the central nervous system (CNS) may be a is made up by mononuclear and polymorphonuclear
contributing factor. In pulp necrosis, the pulpal sensory leukocytes and fibrovascular elements.
neurons are damaged, that is why it does not respond The histological appearance of periapical granuloma
to thermal and electrical stimuli; however, in case of represent every event of periradicular inflammatory
partial necrosis, pulp can be reactive because C-fibers process from the acute response to the end-stage lesion.
are more resistant to hypoxia than A-δ fibers (such a Neighbouring histological features, i.e. necrotic, exuda-
phenomenon is common in multirooted teeth). tive, granulomatous and fibrous zones may penetrate
into surrounding alveolar bone. According to predomi-
d. Periradicular Inflammation (Apical Periodontitis) nant zones, the lesion can be classified as exudative,
Periradicular inflammation is the spread of infection granulomatous, granulofibrotic, etc. (Fig. 3.1).
from pulp into periradicular tissues.
The mountain pass concept: Kronfeld (1955) equated
The presence of bacteria within the root canal system
the micro-organisms in the root canal to an army in the
eventually cause a periapical inflammatory response,
‘mountains’ which enters the ‘plains’ through the
known as apical periodontitis. This is the response of
foramina or ‘the mountain pass’. The bacteria in the
the body’s defense system to the irritation created by
root canal can be compared to an army waiting behind
the bacteria and their by-products.
high, inaccessible mountains, the walls of the canal.
Periapical inflammation is the result of interactions Through the mountain pass (the apical foramen), the
between the bacteria in an untreated infected root canal bacteria (army) try to invade the plain beyond the pass
system and the host’s defense/immune system. As (the periodontium and the bone). The granulation tissue
there is no longer any blood supply to a necrotic pulp, (army of the host) tries to prevent the mountain army
the host’s defense cells cannot reach the source of the from progressing farther. The defending army is
irritation (i.e. the bacteria in the canal) and, therefore, represented by the white blood cells and other cells of
the body is unable to eliminate the infection. Hence, a the granulation tissue. They accumulate near the
chronic inflammatory response develops in the opening of the apical foramen. For a long time there
periapical region. Infections of the root canal system may be no action. Occasionally, a few soldiers of the
usually consist of multiple species of organisms; mountain army descend through the pass, the apical
complex interactions occur where the by-products of
some bacteria contribute to the supply of nutrients for
other species. Once an infection is established within
the root canal system, the number of micro-organisms
gradually increase through normal cell reproduction
and proliferation mechanisms. The nutritional
conditions in each root canal may vary; this explains
the different rates at which periapical tissues respond
and also why there are varying number of bacterias
that can be recovered from root canal system.
Although bacteria are the most common cause of
pulp diseases, dental pulps may also get necrosed
following trauma when the apical blood vessels are
severed. Necrotic debris alone, although stimulating
phagocytosis and tissue repair, may not produce
enough irritation to the periapical region. Fig. 3.1 Zones of sequelae of root canal infection
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 22 Essentials of Endodontics

foramen, but they are usually captured and destroyed The mechanism of referred pain is explained by the
by the defenders, the white blood cells. Then suddenly theory of convergence (the key location is spinal core
the mountain army makes a mass attack and a battle of trigeminal nerve: Spinal cord is divided into
occurs. Such a battle between invading bacteria and (i) Subnucleus oralis, (ii) Subnucleus interpolaris and
body tissues is known as acute inflammation. The (iii) Subnucleus candalis). The nociceptive nerve fibers,
outcome of this battle may vary. The bacteria may win conducting the stimuli from head and neck areas
and invade the plain; then the clinical manifestation converge in the subnucleus candalis (spinal core) of
will be an acute periapical abscess. If the defenders trigeminal nerve. Certain afferent fibers also belong to
(WBCs) are successful, they may overcome the invading other cranial nerves.
bacteria. The bacteria in the canal (mountain army) are When the pain (nerve impulses) gets activated and
eliminated by extraction of the tooth or by sterilization travel the brain centers; these centers may not identify
of the root canal (root canal treatment). the exact cause of painful stimuli.
The granulations shrink, and the white blood cells The clinical features of odontogenic pain are
(WBCs) leave and return into the general circulation. This tabulated in Table 3.1.
explains why the apical granulation tissue disappears
after extraction or after successful root canal treatment. B. Inter-appointment Endodontic Pain (Flare-up)
So the granuloma is a defense against spread of infection. Local anesthesia is an effective means of controlling
It is this tissue with its newly formed capillaries (the pain during endodontic treatment, except while
granulation tissue) which is responsible for repair. treating the ‘hot tooth’ (irreversible pulpitis).
Such patients often carry ice water to help control
e. Referred Pain the pain. Such teeth are mostly prevalent in mandibular
The term ‘referred pain’ implies the pain felt in any part arch. The inferior alveolar nerve block delivered to
of body away from the place of tissue damage. Another attain pulpal anesthesia in such teeth may not be
term ‘odontalgia’ refers to the pain caused by patho- adequate. Even asymptomatic teeth in a mandibular
logical changes in other tissues and reflected on teeth. arch are not properly anesthetized by such blocks.

Table 3.1 Clinical features of odontogenic pain

Disease process Symptoms Radiographic findings Response to pulp testing Response to percussion/
palpation
Pulp diseases
Reversible pulpitis Slight responsive to No change in periapical Respond to pulp tests Not sensitive to percussion/
thermal stimulus radiolucency palpation
Irreversible pulpitis Responsive to thermal No change in periapical Responds (possibly with May or may not have pain
stimulus: may be pain radiolucency extreme pain on thermal on percussion/palpation
stimulus)
Pulp necrosis Not responsive to No change till periapical No response Depends on status of
thermal stimulus areas involved periapical tissues
Periapical diseases
Acute apical Pain on mastication/ May be slight widening Usually not responsive Pain on percussion/
periodontitis chewing of periodontal ligament palpation
Chronic apical Mild discomfort on Apical radiolucency No response Mild discomfort on
periodontitis mastication or putting percussion/palpation
pressure
Acute abscess Significant pain: may Initiation of appearance No response Pain on percussion/
be swelling of radiolucency palpation
Chronic abscess No pain, if draining A radiolucent area No response Not sensitive to percussion/
sinus or pain and at the apex palpation
swelling

3
Condensing osteitis Symptom less: no pain Intermittent radiopacity Usually not responsive Usually not responsive
(increased trabecular
bone density)

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 Pathophysiology of Pain 23

Central core theory may explain the phenomenon: imbalance in host-bacteria relationship induced by
in the mandible; the outer nerves fibers of the inferior intracanal procedures.
alveolar nerve supply the molars while the nerve fibers
for anterior teeth lie deeper. Anesthetic solutions may a. Microbial Causes
not be able to diffuse into all the nerve fibers and The factors associated with precipitation of pain by
provide an adequate block. It is observed that local micro-organisms are:
anesthetic failure after a mandibular block was highest i. Presence of pathogenic bacteria: There is no evidence
in incisors, followed by premolars and molars. on the qualitative or quantitative shift in the
It has also been hypothesized that in symptomatic endodontic microbiota that can cause inter-
teeth the inflamed tissue have an altered resting appointment pain. It is hypothesized that the
potential and reduced threshold of excitability. It was bacterial species associated with such pain are the
shown that anesthetic agents were not able to prevent same as those involved with infected root canals.
the transmission of nerve impulses because of the The change in environment of the bacterial species
lowered excitability thresholds of inflamed nerves. may be a contributing factor.
Various strategies like changing the local anesthetic ii. Virulence of the pathogens: Virulence of endodontic
solution or the injection technique were not successful pathogens may not be a predisposing factor for
in anesthetizing ‘hot teeth’. Accessory nerves have also inter-appointment pain; only effective if conditions
been implicated as a potential reason for the failure of are created for them to exert pathogenicity. (If the
this nerve block (Fig. 3.2). The mylohyoid nerve is the root canal environmental conditions are in some
accessory nerve most often implicated as the cause for way altered by intracanal procedures and as a result
mandibular anesthesia failure. However, inferior become conducive to the expression of virulence
alveolar nerve block combined with mylohyoid nerve genes, microbial virulence can be enhanced and
block did not significantly improve the mandibular inter-appointment pain can ensue).
anesthesia. Combining intraligamentary injection with iii. Microbial synergism: Most of the endodontic
inferior alveolar nerve block injection was found to be pathogens may show virulence only when in
effective. association with other species (synergism), which
can certainly influence pain factor.
Causes of Inter-appointment Pain
iv. Host resistance: Individuals with poor resistance are
The frequency of inter-appointment pain is significantly
more susceptible to postoperative consequences
higher in teeth with periradicular lesions as compared
(prone to develop pain after root canal treatment).
to teeth with normal periradicular tissues. Microbial
Poor resistance can be because of varied factors.
insult is the major cause of inter-appointment pain;
Herpesvirus infection may be one factor that can
however, certain iatrogenic factors do play a key role.
diminish host resistance. Herpesviruses have the
Inter-appointment pain is considered a result of
ability to interfere with the host immune response,
which may trigger overgrowth of pathogenic
bacteria and/or diminish the host resistance to
infection. Herpesviruses may also induce the
release of proinflammatory cytokines by host
defense cells; subsequently, patients with decreased
resistance feel inter-appointment pain.

b. Iatrogenic Causes
Certain iatrogenic causes may lead to inter-appointment
pain; the main causes are:
i. Apical extrusion of debris/chemical agents/over-
extended obturating material: In asymptomatic
periradicular lesions associated with infected teeth,
there is a balance between infecting endodontic
microbiota and the host defense. If during root canal

Fig. 3.2 Failure of mandibular nerve block (implications of

accessory nerves)
preparation micro-organisms are extruded into the
periradicular tissues, the host will have to face a
larger number of irritants, disrupting the balance
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 24 Essentials of Endodontics

between aggression and defense; consequently, an tissues in response to the intensity of injury from the
acute inflammatory response and pain. The risks root canal system. The inflammatory response to tissue
of inter-appointment pain can be even higher in the injury may provide potential for repair of the diseased
event of over-instrumentation; lead to significant tissues. It may result in undesirable effects such as pain
extrusion of debris containing micro-organisms and intensified tissue damage. Chemical mediators
along with mechanical injury to the periradicular released after tissue injury may induce pain due to
tissues. The incidence of pain in re-treatment cases direct effect on the nerve fibers, or can cause pain
with periradicular lesions has been demonstrated indirectly by increasing the vascular permeability;
to be significantly high. Removal of filling material subsequently producing edema and swelling. Bacteria
and also the solvents used during removal of filling that suddenly gain access to the periradicular tissues
may contribute to exacerbation of the periradicular may face two lines of defense; complement system and
inflammation. Virtually, all instrumentation phagocytes (neutrophils and macrophages) present in
techniques promote apical extrusion of debris. the chronic inflamed tissue. The encounter of the
Crown-down techniques, irrespective by hand or bacteria with these host defense mechanisms trigger
engine-driven instrument, usually extrude less the production and release of chemical mediators of
debris; however, qualitative factor is difficult to inflammation, which will induce vascular changes in
control (even a small amount of infected debris with the microcirculation and recruit new phagocytic cells
virulent micro-organisms may exacerbate peri- to the site.
radicular inflammation). Increased vascular permeability along with increased
ii. Incomplete instrumentation/over-instrumentation: hydrostatic pressure is the hallmark of acute inflamma-
The microbiota associated with primary endodontic tion. The increase in the vascular permeability leads to
infections is usually established as a mixed consor- a marked outflow of fluid, which gets accumulated in
tium, and alteration of part of this consortium will the extravascular space. This fluid (inflammatory
affect both the environment and the remaining exudate) may elevate the tissue hydrostatic pressure
species. Incomplete preparation can disrupt the resulting in swelling and pain.
balance within the microbial community by Exudation induces an increase in tissue hydrostatic
eliminating some inhibitory species and leaving pressure, with resultant compression of nerve endings
behind other. Such bacteria, if overgrow, may lead causing pain and swelling.
to exacerbation of periradicular inflammation. A sudden egress of a large mass of bacteria into the
Environmental change (ingress of oxygen in the periradicular tissues represent bacterial cells and their
root canal) may alter the oxidation–reduction by-products that can cause a massive emigration of
potential (Eh) in the root canal; subsequently, lead neutrophils, which may be unable to phagocytose large
to acute exacerbation. This theory is based on the bacterial masses and die subsequently. Consequent
fact that the increase in Eh would induce microbial leakage of lysosomal enzymes and oxygen radicals into
growth pattern to change from anaerobic to aerobic, the surrounding tissues will lead to pus formation
with consequent overgrowth of facultative bacteria. (abscess).
Overgrowing facultative bacteria might precipitate Physical or chemical injury to the periradicular
acute periradicular inflammation. tissues during preparation of root canal can cause
iii. Secondary intra-radicular infections: Secondary degranulation of mast cells, with consequent release of
intra-radicular infections are caused by micro- histamine into the periradicular tissues. Activation of
organisms that were not present in the primary all these lead to pain and swelling.
infection. They may get entry into the root canal
system during treatment, between appointments, Risk Factors for Developing Inter-appointment
or even after the endodontic treatment. If the micro- Pain (Flare-up)
organisms that gain access to the root canal are
successful in surviving and colonizing in a new 1. Age and sex: Females are more prone to flare-up as
environment, a secondary infection will establish compared to males. Flare-up incidence may not be
and may be one of the causes of postoperative pain. related to age.
2. Pulp and periapical status: Teeth with pulpal necrosis
Inflammatory Events Leading to have a much higher incidence of flare-ups than teeth
Inter-appointment Pain
3 Inter-appointment pain is almost exclusively due to the
development of acute inflammation at the periradicular
with a vital pulp. The radiographic presence of a
periapical lesion, particularly larger lesions, also
considered as a risk factor for development of

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 Pathophysiology of Pain 25

flare-ups. The diagnosis of pulp necrosis and acute ii. Incision and drainage/trephination: The rationale for
apical abscess, is more likely to result in a flare-up an incision and drainage procedure is to facilitate the
than any other pulp and periapical disease. evacuation of pus, micro-organisms and toxic products
Interestingly, the presence of a sinus tract virtually from the periradicular tissues. Moreover, it allows for
ensures that a flare-up will not occur. The tract the decompression of the associated increased
functions as a relief valve, releases pressure, reduces periradicular tissue pressure and provides significant
inflammatory mediators and consequently prevents pain relief. Detail procedure of incision and drainage/
the sudden onset of pain. trephination is described in Chapter 23.
3. Patient’s signs and symptoms: A patient complaining iii. Intracanal medicaments: It is established that use
of pain is considerably more likely to experience an of intracanal steroids and a corticosteroid–antibiotic
inter-appointment flare-up than a patient without combination has been shown to reduce post-treatment
prior symptoms. It is established that patient in pain, pain.
which would also increase stress levels; subsequently
affect the immune functions. iv. Occlusal reduction: The teeth with flare-up
4. Treatment factors: There is no universal agreement as condition present with difficulty in biting and chewing,
to whether retreatment results in a higher incidence due to increased levels of inflammatory mediators that
of post-treatment pain/flare-ups than conventional stimulate periradicular nociceptors. Occlusal reduction
root canal treatment. Incomplete debridement has may alleviate the mechanical stimulation and relieve
been traditionally assumed to be a cause of flare-ups; pain.
however, not properly documented. Mostly, flare-
up/pain occurs before obturation phase. c. Drugs
Antibiotics are commonly administered to patients i. Antibiotics: The advancement in our understanding
prior to and after root canal treatment; however, of the biology of the inflammatory process, along with
prophylactic antibiotics are contraindicated for the known risks associated with antibiotics, it is advised
prevention of flare-ups. that the clinician should prescribe antibiotics only in
case of frank abscess.
Treatment of Inter-appointment Pain
ii. Analgesics: The NSAIDs have been shown to be very
The ‘3D’ approach; Diagnosis, Definitive treatment and effective for managing pulpal and periradicular pain.
Drugs has been accepted as treatment protocol for the In patients with known sensitivity to NSAIDs or
inter-appointment pain. aspirin, acetaminophen is preferred for post-treatment
pain. However, NSAIDs are effective in reducing pulpal
a. Diagnosis
and periradicular levels of the inflammatory mediator
The initial phase is diagnosis. Several conditions have PGE2. Ibuprofen is also effective for managing pulpal
been shown to mimic endodontic/odontogenic pain. and periradicular pain of inflammatory origin.
The current episode of pain may be initiating from
another tooth, an unrelated sinus or TMJ-related C.Post-endodontic Pain
condition, is to be thoroughly evaluated. The patient’s
Failure of root canal treatment or sequelae of residual
past history of treatment coupled with consultation
microbial infection leads to pain; soon after root canal
with the previous dental surgeon help reach out at
treatment or may be after prolonged duration.
diagnosis.

b. Definitive Treatment Management

i. Re-treatment: The involved tooth should be • Reducing nociceptive input from the site of injury:
anesthetized prior to re-treatment. The access cavity pretreating with NSAIDs.
should then be opened, cleaned and looked for any • Attenuating the perception of pain in the central
missed out canal orifice. Enhanced magnification and nervous system: pretreat with NSAIDs plus long
illumination are beneficial. The obturated material, if acting local anesthetic.
any, should be removed. Drainage can be established • Steroids can be given as an adjunct anti-inflamma-
through the root canal, reducing the localized tissue tory drug.
pressure. It is suggested that the apical constriction be
sufficiently enlarged to allow for drainage through the
canal.
Pretreatment with either ibuprofen (600 mg) or
flurbiprofen (100 mg) is effective for management of
post-treatment pain. Some patients do not tolerate
3

t.me/Dr_Mouayyad_AlbtousH
 26 Essentials of Endodontics

NSAIDs; pretreatment with acetaminophen (1000 mg) and source of pain, which will facilitate correct
is effective for reducing post-treatment pain in such diagnosis. Pain can be divided into two types:
patients.
a. Primary pain: The site and source of pain are
The long-acting local anesthetics (i.e. bupivacaine,
coincidental and in the same location.
ropivacaine, etc.) can provide an increased duration of
post-treatment analgesia beyond the period of b. Heterotopic pain: The site and source of pain are
anesthesia. The long-acting local anesthetics can different. It can be divided into three general types:
provide a duration of analgesia up to 8–10 hours. i. Central pain: Pain derived from the central nervous
system and perceived peripherally.
NON-ODONTOGENIC PAIN ii. Projected pain: Pain felt in peripheral distribution
Odontogenic pain is the most common pain in orofacial of the same nerve that mediated the primary
region; however, when clinical examination excludes nociceptive input.
odontogenic cause, other causes of orofacial pain should iii. Referred pain: Spontaneous heterotopic pain, felt at
be considered. Involvement of orofacial organs, such the site of pain with separate innervation to the
as nose, throat, eye, ear, glands, etc. should be evaluated primary source of pain.
thoroughly to reach out at diagnosis. Pain in the The most important non-odontogenic pains,
orofacial region may stimulate as odontogenic pain, indirectly related to teeth and surrounding tissues, are
posing a diagnostic dilemma for dental practitioner. described.
Orofacial pains can be acute (trigeminal neuralgia,
cluster headache, sinusitis, sialolithiasis, etc.) or chronic 1. Pericoronitis
(postherpetic neuralgia, TMJ disorder, cheek-muscle Pain commonly arise from gingiva/mucous membrane
pain, etc.). around any erupting teeth, which gets infected.
The nature and duration of acute and chronic non- Mandibular third molars are usually involved. The pain
odontogenic pain is depicted in Table 3.2. may be constant or intermittent; biting triggers pain.
Acute pericoronitis involves bacterial infection around
Clinical Characteristics semierupted mandibular third molar. Trismus may be
Clinical characteristics are usually varied and may mimic associated with this tooth because the tooth is close to
other pain disorders which may not originate in the oro- the mandibular insertion of temporalis muscle.
facial region. The extent of pain may vary from very mild Analgesics are prescribed to relieve pain and local
and intermittent pain to severe, sharp and continuous. irrigation of the tissues help in healing. Antibiotics are
Pain may not always originate from dental generally not indicated, unless there are signs of severe
structures; it is important to distinguish between site infection (fever, malaise, etc.).

Table 3.2 Non-odontogenic pain—nature and duration

Condition Nature of pain Trigger zone/stimulation Duration of pain
Acute
Trigeminal neuralgia Lancinating (episodic) Light touch triggers pain Few seconds
Cluster headache Severe ache (episodic) Rapid eye movement (REM) 30–45 minutes
sleep, alcohol
Acute otitis media Severe ache, throbbing Lowering head triggers pain Few hours; may linger for days
(non-episodic)
Sinusitis Moderate ache in maxillary Lowering head triggers pain Continuous for days
teeth (non-episodic)
Sialolithiasis Sharp pain (episodic) Biting induce pain Pain when triggered
Chronic
Postherpetic neuralgia Deep ache, burning Spontaneous For long duration
TMJ disorders Dull ache, sharp Opening mouth/chewing For long duration
triggers pain

3 Cheek-muscle pain
Myalgia
Dull ache, severe episodes
Dull ache
Spontaneous
Stress, clenching of teeth
Usually for few weeks
Usually for few weeks

t.me/Dr_Mouayyad_AlbtousH
 Pathophysiology of Pain 27

2. Alveolar osteitis temperature. When multiple maxillary teeth feel pain, it

The most common complication of extraction of indicates pain of sinus origin rather than odontogenic pain.
mandibular teeth is alveolar osteitis (dry socket), which Pain may be elicited by palpation of the infraorbital
is rarely seen in maxillary teeth. Unhealed socket results regions or when the patient is asked to bow the
in entrapment of food debris, which may aggravate maneuvering the head to the levels of the knees. The
bony nerve endings. Pain is dull and throbbing; usually absence of any inflammation around teeth may further
develops two-three days after extraction. lead to the conclusion that there is sinus inflammation.
Irrigating the socket with mild antiseptics along with Treatment should be directed towards the maxillary
analgesics are effective in pain control. An obtundent
sinus infection. Mostly acute sinusitis is of viral origin
dressing is given to promote healing. Antibiotics are
and requires nasal decongestants. In case of bacteria-
not indicated.
induced sinusitis, a regimen of antibiotics is additionally
3. Myofascial pain prescribed. Antiallergic drugs are also effective.
Myofascial pain is described as non-pulsating and
5. Migraine and trigeminal cephalgia
aching pain, which occurs continuously as compared
to pulpal pain. Patients are unable to locate the source Headache is the pain localized to cranium. Two primary
of pain and often believe pain is originating from the headache types that may present as toothache are
tooth. Tooth sensitivity to temperature, percussion or migraine and trigeminal cephalgia. Trigeminal
occlusal pressure may be felt as a result of referred pain cephalgia is further categorized as cluster headache,
from the offending muscle. Pain might be associated paroxysmal hemicranic and neuralgiform headache.
with extended muscle use and get exacerbated with Migraines are typically unilateral, moderate to severe
emotional stresses. Palpation of the trigger point (a pains of pulsatile and throbbing quality, which may
localized hyper-excitable area within the muscle) is able last between few hours and days. Migraine is often
to reproduce the toothache. accompanied by nausea, vomiting and may present
Anesthetizing the strained muscle rather than the with or without neurological symptoms.
tooth alleviates pain. Warm or cold compresses, muscle Cluster headache is common in young adults (age
stretching, massage, etc., facilitate relief of pain. 20–40 years). Pain being boring and severe, usually
located around orbits. Pain may last for few minutes
4. Pain of sinusitis and may linger for hours.
Sinusitis is a common ailment. The roots of the Collectively, such pains are referred to as neuro-
maxillary dentition are usually in intimate contact with vascular orofacial pain, which is usually treated with
and even may be protruding into the sinus cavity. The symptomatic drugs.
inflammation and infection in sinus have direct effect
on roots of maxillary teeth; and the infectious process 6. Trigeminal neuralgia
in the dentition may effect sinus as an acute or chronic The most common branch of trigeminal nerve involved
sinusitis. In such cases, patients may present with facial in neuralgia is the mandibular nerve followed by
pain and pressure in the maxillary posterior region. maxillary nerve. The pain in trigeminal neuralgia is
Other symptoms such as headache, nasal discharge or often severe and intense. There is often a trigger zone,
congestion and ear pain may also be recognized as sinus which when stimulated produces severe pain. Rarely,
disease. Sinus pain can also present as a continuous a tooth can be a trigger zone; if so, can pose a diagnostic
dull ache or diffuse lingering pain in the maxillary teeth challenge. The differences between trigeminal neuralgia
with sensitivity to percussion, mastication and/or and atypical facial pain are explained in Table 3.3.

Table 3.3 Differences between trigeminal neuralgia and atypical facial pain
Trigeminal neuralgia Atypical facial pain
Age and sex Older adults; female to male ratio is 2 to 3 Young adults; mostly females
Location of pain Along distribution of branches of the trigeminal One sided; may be on both sides
nerve. One sided usually.
Duration of pain Less; in minutes Constant and more
Quality of pain Severe (sharp, stabbing, lancinating) Moderate (diffuse, burning, aching, dull)
Trigger zones
Treatment of choice
Stimulation of trigger zones
Carbamazepine
No trigger zone
Tricyclic antidepressants 3

t.me/Dr_Mouayyad_AlbtousH
 28 Essentials of Endodontics

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t.me/Dr_Mouayyad_AlbtousH
Chapter
4
Drugs used
in Endodontics

The primary goal of endodontic treatment is to in alleviating fear and anxiety (discussion with patient
eradicate micro-organisms along with harbouring sites, identifying reasons of fear along with counseling will
so as to achieve requisite healing of the periapical minimize the fear level). In case psychosedation is not
tissues. The treatment may be accompanied by anxiety, achieved, certain drugs (pharmacosedation) are tried.
pain and/or problem of persistent infection. Certain Anxiolytic sedative-hypnotic drugs can be prescribed
drugs/medicaments are to be prescribed in such in routine; rarely anesthesia is required to manage fear
situations. The operator should be aware of the and anxiety.
indications, contraindications, actions/reactions and
also the side effects of the drugs, which can be A. Sedative-hypnotic Drugs
prescribed to control pain, anxiety and/or infections. Various drugs are used as sedative-hypnotic to control
WHO (1966) defined drug as ‘any substance or product fear and anxiety in a dental set-up. Apart from relieving
that is used or intended to be used to modify physiological anxiety, these drugs are also used for various clinical
systems or pathological state for the benefit of the recipient’. situations, such as:
A pharmaceutical medicine or medicinal product is • Insomnia
defined as ‘any chemical agent intended to be used in the • During treatment of epilepsy
diagnosis, cure, treatment or prevention of disease’. Various • As a component of balanced anesthesia
drugs are used before, during and after endodontic
• Control of ethanol or other sedative-hypnotic
procedures.
withdrawal state.
The drugs used in endodontics are broadly
• Muscle relaxant in specific neuromuscular disorders.
categorized as:
• Diagnostic aids for treatment in psychiatry.
I. Management of fear and anxiety
II. Effective pain control Side-effects
III. Management of infection • Dependence
IV. Miscellaneous • Depression of central nervous system functions
• Amnestic effects
I. MANAGEMENT OF FEAR AND ANXIETY • Cause depression when administered with other
drugs, including ethanol.
Fear and anxiety can be identified by either behavioural
changes or recognizing physical changes, such as Classification
dilated pupils, pale skin, excessive sweating, tingling
The sedative-hypnotic drugs are classified as:
of extremities and increase of blood pressure. The
reasons for fear in a dental clinic are fear of pain, a. Barbiturates
belonephobia (fear of needle and injection) and i. Ultrashort acting: Methohexital, thiopental sodium
unpleasant past experience of self and peer groups. ii. Short acting: Secobarbital (Seconal), pentobarbital
The initial management of fear and anxiety is iii. Intermediate acting: Amytal (amobarbital) and
psychosedation (an act of making calm through Tuinal (secobarbital and amobarbital)
psychological motivation). Psychosedation is mainly iv. Long acting: Phenobarbital and barbital.
through verbal and non-verbal (body language) b. Benzodiazepines
communication of the doctor, which affects the patient i. Short acting: Midazolam, triazolam, prazepam

30

t.me/Dr_Mouayyad_AlbtousH
 Drugs used in Endodontics 31

ii. Intermediate acting: Alprazolam, lorazepam, its long duration of action makes it a preferred
oxazepam choice for longer duration surgeries (intravenous
iii. Long acting: Diazepam, nitrazepam, flurazepam. and intramuscular injections are generally painful).
c. Non-benzodiazepines: Imidazopyridine derivatives; The elimination time is prolonged, which may lead
zolpidem, zaleplon, zopiclone. to some lingering effect (hangover) of sedation.
d. Antihistamines: Diphenhydramine, promethazine, ii. Midazolam (Versed): Midazolam is about 2.5 times
hydroxyzine. as potent as diazepam and is used both orally and
e. Anticholinergic: Glycopyrrolate, atropine/scopola- as intravenous injections. The recommended dose
mine. is 0.5–1.0 mg/kg orally and 0.05–0.15 mg/kg
intravenously. Midazolam has a significantly
f. Miscellaneous drugs: Opioids, propofol, chloral
shorter half-life than diazepam, making it an ideal
derivatives, meprobamate. agent for short procedures. It does not have any
a. Barbiturates ‘hangover’ effect. Respiratory depression is of
The varying dose of barbiturates produces different concern with the use of midazolam.
level of CNS depression, such as relaxation (sedation) iii. Triazolam (Halcion): Triazolam is a potent sedative
and drowsiness (hypnosis). Barbiturates enhance the agent. It is used mainly orally (0.25 to 0.50 mg). One
activity of neurotransmitter that inhibits the activity of hour prior intake of triazolam is quite effective in
nerve cells in the brain. At higher doses, barbiturates producing sedation and amnesia.
can produce general anesthesia and even coma. iv. Lorazepam (Ativan): Lorazepam has approximately
10–20 hours as half-life. The adult dose for dental
Barbiturates are mainly used as minor tranquilizers
sedation range from 0.5 to 4.0 mg depending upon
to reduce anxiety levels and mental acuity. Barbiturates
the procedure undertaken. The onset of action
were initially used in oral surgery for third-molar occurs within 60 minutes.
extraction; however, their tendency to cause respiratory
The dosage of drugs commonly used for sedation
depression has led to its limited use in the dental clinic. and hypnosis are tabulated in Table 4.1.
100–200 mg secobarbital and 15–30 mg pentobarbital
thrice daily are effective sedative-hypnotic drugs. c. Non-benzodiazepines
Non-benzodiazepines are chemically distinct drugs;
b. Benzodiazepines however, their effects and clinical profiles are
Benzodiazepines are categorized as non-barbiturate indistinguishable from benzodiazepines. The effects of
sedatives. These are less potent than barbiturates. The non-benzodiazepines can be reversed using benzodia-
main benefit of using benzodiazepine instead of zepines antagonist, flumazenil. It is hypothesized that
barbiturate is the decreased occurrence of hangover their action is selective (on one subunit out of five BZ
effect that often accompanies barbiturates. The receptors), which reduces their potential for cognitive
commonly used benzodiazepines are: impairment.
i. Diazepam (Valium): Diazepam effectively reduces The commonly used non-benzodiazepines are:
anxiety and is a profound amnestic. Diazepam is i. Zolpidem (Ambien): Zolpidem has rapid onset of action
safe and effective both orally and intravenously. (within 30 minutes) and has short half-life. The usual
5.0–10 mg dose is effective orally and 2.5–5.0 mg adult dose is 10 mg (5.0 mg is advised for geriatric
intravenously. In the case of intravenous sedation, patients). The ‘hangover’ effects are minimum.

Table 4.1 Dosages of drugs commonly used for sedation and hypnosis
Sedation Hypnosis
Drug Dosage Drug Dosage
Alprazolam (Xanax) 0.25–0.5 mg 2–3 times daily Chloral hydrate (Somnote) 500–1000 mg
Chlordiazepoxide (Equilibrium) 10–20 mg 2–3 times daily Estazolam (Prosom) 0.5–2.0 mg
Diazepam (Valium) 2.0–10.0 mg daily Lorazepam (Ativan) 0.25–4.0 mg
(5.0 mg twice daily)
Lorazepam (Ativan) 0.25–2.0 mg once or twice daily Secobarbital (Seconal) 100–200 mg
Oxazepam (Serepax) 15–30 mg 3–4 times daily Triazolam (Halcion) 0.125–0.5 mg
Phenobarbital (Luminal)
Propofol (Diprivan)
15–30 mg 2–3 times daily
2.0–2.5 mg/kg daily
Zaleplon (Sonata)
Zolpidem (Ambien)
5.0–20 mg
5.0–10 mg 4

t.me/Dr_Mouayyad_AlbtousH
 32 Essentials of Endodontics

ii. Zaleplon (Sonata): Zaleplon is available in 5.0 mg and ii. Propofol (Diprivan): Propofol in low dose is an
10.0 mg capsules (dose ranges from 5.0 to 20.0 mg). effective sedative. It is highly lipid-soluble, which
It has faster onset of action and short half-life. accounts for its rapid uptake and short duration of
iii. Zopiclone (Zimovane): The average adult dose is action. It is a potent amnestic and a powerful
7.5–15.0 mg (available as 5.0 mg and 7.5 mg tablets). antiemetic. In an adult, 2.0–2.5 mg/kg (maximum
It has rapid onset of action and short half-life. 250 mg) is the recommended dose. Propofol may
lead to mild itching/rashes or slight burning.
d. Antihistamines
Antihistamines cause sedation as a side effect (mainly Premedication with Sedative Drugs
used to manage allergic reactions). Diphenylhydramine
(Benadryl) is commonly used antihistamine for the Premedication is advised before any surgical procedure
treatment of allergic cough. It is also effective in the to minimise anxiety and other associated features. The
relief of nausea, vomiting and vertigo. The onset of sedatives are preferred as premedication agents prior
action is within 15–30 minutes and the adult dosage is to anesthesia.
20–25 mg for effective sedation. Promethazine Indications
(Phenergan) is also used as sedative. The adult dose • Patients undergoing surgical procedures
for sedation is 25–50 mg. Another commonly used
• Disabilities or special need patients, especially
antihistamine is hydroxyzine (Atarax), whose onset of
children (Autistic, Asperger’s, Down’s syndrome)
action is within 15–30 minutes and the adult dose is
50–100 mg. Hydroxyzine has minimal side effects on • Patients having past experience of emergency during
cardiovascular and respiratory functions. Mostly anesthesia.
antihistamines have anticholinergic properties. Contraindications
e. Anticholinergic • Anticipated airway difficulty
Anticholinergic drugs block acetylcholine from binding • Obstructive sleep apnea
to its receptors on certain nerve cells. They inhibit • Acute systemic illness, e.g. severe sepsis
parasympathetic nerve impulses (responsible for • Severe renal or hepatic impairment
involuntary movement in the gastrointestinal tract and • Previous allergy to sedative drugs
other parts of the body). The nerve impulses also control
functions such as salivation, digestion, urination, etc. Advantages
Atropine and scopolamine are effective in blocking • Reduces both patient and parental anxiety
short-term memory; depresses CNS, cause amnesia, • Provide effective anterograde amnesia
drowsiness and sleep. These drugs decrease salivary • Reduces postoperative behavioural changes
secretions. Glycopyrrolate may be preferred over
atropine/scopolamine for its superior anti-sialagogue Disadvantages
effects, less pronounced cardiac effects, and poor CNS • Non-compliance by the patient may worsen anxiety
penetration. The recommended dose of glycopyrrolate • Some drugs like midazolam may lead to paradoxical
is 0.1–0.3 mg intramuscular and 1.0–2.0 mg orally. reactions
Anticholinergic may lead to dry mouth and retention • May potentiate the effect of other sedative drugs, e.g.
of urine. opioids.
f. Miscellaneous drugs
B. Anesthetic Agents
i. Opioids (Morphine): Opioids are seldom used alone
for sedation. These are effective in producing Local anesthetics are the fastest and most effective
euphoria, sedation, and analgesia; however, may drugs for the management of fear and anxiety; best
be accompanied by nausea and respiratory suitable for pain control also. A variety of local
depression. Because of its slow onset and longer anesthetic agents is available for specific dental
duration of activity, it is commonly used in procedures, possessing requisite properties, such as
anesthesia for postoperative pain management time of onset and duration, hemostatic control and
rather than intravenous sedation. minimum side effects.
Meperidine hydrochloride and fentanyl citrate are The commonly employed anesthetic agents are:
the most commonly used opioids for intravenous i. Lidocaine/Lignocaine/Xylocaine: It is available in three

4 sedation and general anesthesia. The peak effect

occurs in 15–30 minutes and the analgesic effect
may last for 4 hours.
formulations: 2.0% without vasoconstrictor (plain),
2.0% with 1:100,000 epinephrine (vasoconstrictor),
and 2.0% with 1:50,000 epinephrine. The onset of

t.me/Dr_Mouayyad_AlbtousH
 Drugs used in Endodontics 33

action is fairly rapid (3–5 minutes). It is also These agents alone and in various combinations are
available as topical solution (20–40 mg/ml) with being used as topical anesthetic agent. A commercially
2.0% and 5.0% concentrations. Lidocaine without available EMLA cream (lignocaine and prilocaine: 2.5%
vasoconstrictor has anesthetic effect for 1–2 hours; each) is a common topical anesthetic agent.
however, pulpal anesthesia is only for 5 to 10
minutes, so not preferred for most dental proce- Anesthesia Delivery Systems
dures. The formulations with the epinephrine The intraoral local anesthesia is associated with certain
(vasoconstrictor) have anesthetic effect for 1–1.5 drawbacks, such as patient's fear of injection and the
hours on pulp. The 1:50,000 epinephrine concentra- perception of being painful. New injection delivery
tions are advantageous for hemostasis in surgical techniques, including the computer controlled local
sites; however, not useful for pulpal anesthesia. The anesthetic delivery vehicles, have been introduced that
overdose of lignocaine may lead to drowsiness, loss provide reliable anesthesia and do not result in undesir-
of consciousness and respiratory arrest. able extraoral soft tissue anesthesia.
ii. Mepivacaine: Mepivacaine is available in two The commonly employed delivery systems are:
formulations: 3.0% plain solution and 2.0% solution a. Computer controlled technology
with 1:20,000 levonordefrin (vasoconstrictor). The i. Wand system (Milestone Scientific)
plain solution has effective anesthetic duration of ii. Comfort Control Syringe (Dentsply).
20 to 40 minutes for pulpal lesions. The vaso-
constrictor containing solution provides the pulpal b. Intraosseous delivery system
anesthesia for 1–1.5 hours. The levonordefrin i. Stabident system (Fairfax Dental)
vasoconstrictor is less likely to produce cardiac side ii. X-Tip system (X-Tip technology)
effects (palpitations), than epinephrine; however, iii. Intraflow system (IntraVantage)
it has the potential to increase blood pressure.
a. Computer controlled technology
iii. Bupivacaine: Bupivacaine is four times potent than The systems, which employ computer controlled
lignocaine, mepivacaine and prilocaine. It is technology in administration of local anesthesia are:
available as 0.5% solution with 1:200,000 epine-
i. The Wand system utilizes computer microprocessor
phrine. Bupivacaine exhibits a remarkable increase
to control the flow rate and also the fluid pressure.
in the duration of anesthesia; however, it may
An electronically controlled motor delivers the
display a slightly slower time of onset (5–10
anesthetic solution at a slow rate. The delivery of
minutes). Bupivacaine is preferred in regional
anesthetic solution into any injection site is carried
nerve block injection techniques with mandibular
out at a rate below the threshold of pain. The small
blocks. As a block, pulpal anesthesia is effective
diameter of the syringe/handpiece facilitates stable
up to seven hours (preferred in lengthy dental
grip, subsequently less pain to the patient.
procedures).
ii. The Comfort Control Syringe is an electronic,
iv. Articaine: Articaine is one and a half time potent computer-controlled anesthetic delivery system.
than lignocaine. It is available as a 4.0% solution The Syringe houses the anesthetic cartridge directly
with 1:100,000 epinephrine. The anesthetic effect behind the needle, just as in a conventional syringe;
remains potent for less than one hour; usually not facilitating finger tips to control the delivery. It has
preferred in dental procedures. It has also shown five pre-programmed speeds for different injection
risk of nerve paresthesia, particularly for inferior techniques and can be used for all injection techniques.
alveolar and lingual nerve block injections. The
solution is avoided in females who are breast- b. Intraosseous delivery system
feeding; may be excreted in milk. The technique of delivering local anesthetics directly
v. Prilocaine: Prilocaine is slightly less potent and into alveolar bone (intraosseous) in close proximity to
considerably less toxic than lidocaine. The contra- root apices in not new; however, electronic delivery
indications for use of prilocaine, include patients methods have greatly improved the convenience of
with history of cardiac/respiratory failure due to intraosseous injections. The intraosseous technique is
hypoxia. Prilocaine is available as a 4.0% solution quite reliable for pulpal anesthesia for one or two teeth
with 1:200,000 epinephrine. The solution is effective and is particularly useful to anesthetize the ‘hot tooth’.
The systems used are:
for 40 to 60 minutes in case of pulpal involvement.
The main advantage is the decrease in side effects
due to the lower vasoconstrictor concentration.
i. The Stabident system is a two-part system with a
separate perforated needle. A bur is first used to
4

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 34 Essentials of Endodontics

penetrate the house using a slow speed handpiece observation and monitoring of the patient must be carried
after which the anesthetic injection needle is passed out during general anesthesia to manage the airway.
through the perforation directly into the cancellous
c. Oral sedation
bone.
ii. The X-Tip system is also a two-part system; in place Oral sedation is considered ideal for patients requiring
of the perforated needle, a cannular guide is used short and moderate duration dental procedures.
for insertion of the anesthetic injection needle into For an endodontic procedure, lasting up to one hour,
the cancellous bone. Triazolam, a short-acting benzodiazepine (0.25–0.5 mg),
iii. The Intraflow system is a one-step technique utilizes can be given one hour before the procedure. Triazolam
a low-speed handpiece with a foot-pedal control provides anxiolytic, hypnotic, and amnesic effects,
system that permits perforation and injection into which are desirable in endodontic patients. It has a
the site immediately. relatively short half-life with minor ‘hangover’ effects.
As the intraosseous injections are delivered into the The antihistamines have also been used as sedatives for
highly vascular cancellous bone tissue; use of endodontic procedures. Diphenhydramine (Benadryl
vasoconstrictor in anesthetic agents is not advised due 50 mg), hydroxyzine 50–100 mg, promethazine
to rapid uptake of the agent into the circulatory system, (Phenergan) 25–50 mg may be prescribed one hour prior
subsequently increasing patient's heart rate. to the endodontic procedure.
Advantages
Techniques of Anesthesia • Effective in endodontic procedures
a. Conscious sedation • Favourable patient acceptance
Sedation is a state of drowsiness or mental relaxation. • No fear of implication of intravenous route
The operator should evaluate the patient's level of • Safe when used in recommended dosages (rarely
anxiety in a dental clinic. Patients with a history of contraindicated)
claustrophobia, low pain tolerance, unpleasant dental
experiences in childhood are favourable candidates for Disadvantages
sedation. • Inability to modify dose of the drug for individual
Conscious sedation is a low level of sedation patients and in specific cases
produced by pharmacologic/nonpharmacologic d. Intramuscular/intravenous/intranasal sedation
method. It retains the patient's ability to preserve the
The intramuscular/intravenous route of drug adminis-
airway and the patient reacts to the physical stimulation
tration is preferred where oral administration is
as in routine. The drugs used in conscious sedation
difficult. Ketamine is an ideal drug to be used via intra-
should possess a safety margin, to prevent total loss of
muscular route. Midazolam is used for intramuscular
consciousness.
and intranasal sedation.
b. General anesthesia Benzodiazepines followed by an opioid are used to
General anesthesia is a state of controlled unconscious- intensify the level of sedation; also provide sufficient
ness, accompanied by loss of protective reflexes. This analgesia. A benzodiazepine-opioid combination for
form of anesthesia is the most dependable anesthesia intravenous sedation is preferred because both are
modality. It is indicated for management of highly reversible. An adult escort is required along with the
anxious and phobic patients undergoing endodontic patient because recovery from intramuscular/
surgical procedures. intravenous drugs may be prolonged. Sometimes
In endodontics, general anesthesia is indicated to intravenous administration of flumazenil/naloxone is
drain abscess of painful non-vital tooth. In such required to achieve reversal in intramuscular/
instances, a general anesthetic is administered on first intravenous drugs.
sitting; subsequently, after completion of the emergency Advantages
procedure, the endodontic procedures can be carried • Maintains control over the patient’s level of sedation
out in routine. (dose can be controlled by evaluating sedation).
The dental procedure, if expected to last longer than • Favourable patient’s acceptance.
an hour, or when considerable water spray is going to

4 be used, the airway can be protected with endotracheal e. Inhalation

intubation; however, for short duration cases endo- Nitrous oxide is a colourless and virtually odourless
tracheal intubation is rarely required. A continuous gas with a faint, sweet smell. It is an effective analgesic/

t.me/Dr_Mouayyad_AlbtousH
 Drugs used in Endodontics 35

anxiolytic agent causing central nervous system (CNS) reduced pain threshold. Blocking the development of
depression and euphoria with little effect on the hyperalgesia is the first step in management of pain.
respiratory system. Analgesic effect of nitrous oxide is Effective management of pain depends upon the
initiated by neuronal release of endogenous opioid following features:
peptides with subsequent activation of opioid receptors. • Diagnosing cause of the pain
The flow of oxygen is adjusted to 5–6 liters per minute • Use of analgesic as premedication along with
before initiating inhalation process. Nitrous oxide is sedative drugs
activated at a flow of one liter per minute; oxygen level
• Use of anesthesia, when required
is decreased simultaneously. Process is repeated till
sedation is achieved. • Acupuncture/laser acupuncture, as per need.
Inhalation process is practical and effective; however, The introduction and subsequent application of
it is contraindicated in certain conditions, such as: analgesic agents to eliminate the physical and
psychological effects of pain should be carefully
• Chronic obstructive pulmonary diseases.
assessed. The specific pathology of pain should be
• First trimester of pregnancy.
diagnosed before prescribing analgesics.
• Severe emotional disturbances or drug-related
The types of analgesics used in endodontics are:
dependency.
1. Non-narcotic/non-opioid analgesics
• Methylenetetrahydrofolate reductase deficiency.
• Cobalamin deficiency. 2. Opioid analgesics
3. Corticosteroids.
f. Hypnosis 4. Alternative analgesics (acupuncture)
Hypnosis implies inducing depression in central
nervous system, which resembles normal sleep. Agents 1. Non-narcotic/Non-opioid Analgesics
that produce these effects are referred to as sedative- Non-narcotic/non-opioid drugs are the class of drugs
hypnotics. which function by inhibiting cyclooxygenase enzymes
Various investigators have confirmed that hypno- (COX), which produces prostaglandins. There are two
therapy prior to dental surgery can significantly help types of COX enzymes, COX-1 and COX-2. Both
patients to overcome their apprehension and anxiety; enzymes produce prostaglandins, responsible for
also helps them minimize the use of analgesics inflammation and pain.
following the surgery. The non-narcotic/non-opioid analgesics are of
following types:
II. EFFECTIVE PAIN CONTROL a. Nonselective COX inhibitors [non-steroidal anti-
The International Association for the Study of pain inflammatory drugs (NSAIDs)]
defines pain as ‘an unpleasant sensory and emotional • Salicylates: Aspirin, sodium salicylate
experience arising from actual or potential tissue damage or • Propionic acid derivatives: Ibuprofen, naproxen,
described in terms of such damage’. ketoprofen.
Pain may be categorized as (i) acute pain and (ii) chronic • Anthranilic acid derivative: Mefenamic acid,
pain. flufenamic acid
Features of acute pain • Aryl-acetic acid derivatives: Diclofenac,
• Generally has a known cause aceclofenac.
• May last from seconds to hours • Oxicam derivatives: Piroxicam, tenoxicam.
• May be associated with tachycardia and anxiety • Pyrrolo-pyrrole derivative: Ketorolac
• Subsides after removal of the stimulus. • Indole derivative: Indomethacin.
Features of chronic pain • Pyrazolone derivative: Phenylbutazone, oxyphen-
butazone
• May last from months to years
• Usually associated with decreased functions • Aniline derivative: Acetaminophen (paracetamol)
(only analgesic effect)
Management of Pain b. Preferential COX-2 inhibitors
• Nimesulide
Acute inflammation is associated with a condition
known as hyperalgesia, characterized by spontaneous
pain, an exaggerated response to stimulation, and a
• Meloxicam
• Nabumetone.
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 36 Essentials of Endodontics

c. Selective COX-2 inhibitors analgesic onset and peak effect, but has a longer
• Celecoxib duration of action (longer half-life of 13 hours).
• Etoricoxib iv. Ibuprofen: Ibuprofen is one of the most predomi-
• Parecoxib nantly used analgesic. A 400 mg dose of ibuprofen
d. Analgesic-antipyretics with poor anti-inflammatory action has longer duration and greater peak analgesic
• Para-aminophenol derivatives: Paracetamol effect than 600 to 1,000 mg of aspirin or acetamino-
(acetaminophen) phen. Ibuprofen may cause gastric bleeding and
ulceration, especially with high doses and chronic use.
• Pyrazolone derivative: Metamizol, propyphenazone.
v. Indomethacin: Indomethacin is more effective than
• Benzoxazocine derivative: Nefopam.
aspirin and also more toxic. It is usually prescribed
a. Nonsteroidal anti-inflammatory drugs (NSAIDs) in severe pain, like osteoarthritis, etc. Indomethacin
(Non-selective COX inhibitors) is contraindicated in pregnancy.
Traditional NSAIDs produce analgesia by their actions b. Preferential COX-2 inhibitors
on peripherally inflamed tissues as well as on certain
Nimesulide is a weak inhibitor of synthesis of prosta-
regions of the brain and spinal cord. The NSAIDs have
glandins. 100 mg dose is effective in relieving mild pain.
been reported to be effective for managing pulpal and
It is not preferred in children.
periradicular pain. In patients with known sensitivity
to NSAIDs or aspirin, and in those who have c. Selective COX-2 inhibitors
gastrointestinal ulcerations or hypertension due to renal Rofecoxib, valdecoxib and celecoxib are commonly
effects of NSAIDs, acetaminophen should be preferred available COX-2 inhibitors as pain relieving drugs. The
for such pain. Pretreatment with NSAIDs has been adverse reactions, such as gastrointestinal ulceration
effective in irreversible pulpitis. and bleeding etc. are minimum with their use.
The commonly used nonsteroidal anti-inflammatory Rofecoxib is preferred in comparison to celecoxib and
drugs are: valdecoxib because of following advantages:
i. Salicylates (aspirin): Aspirin is considered as the • It is not contraindicated in patients with a history of
most common remedy for acute pain. It reversibly sulphonamide allergy.
inhibits cyclooxygenase enzyme, blocking synthesis • The duration of action of rofecoxib is sufficiently long
of prostaglandins. It inhibits migration of to allow single daily dose.
polymorphonuclear cells and macrophages into the • 50 mg rofecoxib is comparable to 400 mg of ibuprofen
site of inflammation. It is effective in patients in onset and peak pain relief.
susceptible to stroke and thromboembolic heart
attack. Prolonged use of aspirin may lead to d. Analgesic-antipyretics with poor anti-inflammatory
gastrointestinal problems and also bleeding from action
the gut. 300–600 mg, 6–8 hourly dose is effective. Acetaminophen and certain allied derivatives are
ii. Acetaminophen: Analgesic and antipyretic properties considered week anti-inflammatory agents, even
of acetaminophen are comparable to those of though they inhibit prostaglandins and reduce fever.
aspirin. Unlike aspirin, gastrointestinal irritation or Acetaminophens may not adequately block COX in the
prolong bleeding is not the problems with aceta- peripheral nervous system; action mainly on central
minophen. 300 gm of acetaminophen can effectively nervous system.
produce analgesic effect.
Commonly prescribed analgesics in endodontic clinic
Like opiates, acetaminophen has little anti-
• Ibuprofen 200 mg, 400 mg, 600 mg
inflammatory effect but provide analgesia and anti-
pyretic effects similar to aspirin. 90 to 95% • Paracetamol 650 mg
acetaminophens are metabolized in the liver. Four • Diclofenac 50 mg, 100 mg
percent may get metabolized into toxic metabolites. • Aceclofenac 250 mg
Because of this reason high dose and long-term use • Tramadol 50 mg
of acetaminophen may cause liver damage. One • Ketorol DT 10 mg
main advantage of acetaminophen is that it has no • Nimesulide 100 mg
effect on blood platelets.
2. Opioid Analgesics
4 iii. Naproxen: Naproxen is one of the effective analgesic.
A 220 mg dose of naproxen sodium (equivalent to
200 mg of ibuprofen) is effective in producing
Opioid analgesics activate receptors that inhibit
transmission of the nociceptive signals from the tri-

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 Drugs used in Endodontics 37

geminal nucleus to the higher brain centers and activate tinnitus, etc. Vomiting is less frequent. Pentazocine
peripheral receptors to reduce pain. Their use is limited is indicated for postoperative and moderate to
due to the adverse effects that include nausea, vomiting, severe pain in burns, trauma, fracture, cancer, etc.
drowsiness, dizziness, constipation and respiratory Recommended dose is 25 mg oral or 30 mg/ml
depression; however, by chronic use the patient may intramuscular, as and when required. Pentazocine
develop physical tolerance and dependence. is a ‘ceiling’ drug; dose cannot be increased in case
The opioid analgesics are classified as: of increasing pain.
a. Natural opium alkaloids: Morphine, codeine Safety and efficacy of pentazocine in children younger
b. Semisynthetic opiates: Diacetylmorphine (Heroin), than 12 years of age has not been established.
pholcodine. iv. Butorphanol (Butrum): Butorphanol is more potent
c. Synthetic opioids: Pethidine (Meperidine), propoxy- than pentazocine. It is indicated for postoperative
phene (Methadone), tramadol, fentanyl, pentazocine, and other short lasting painful conditions. It should
butorphanol. be avoided in patients with cardiac ischemia.The
duration of action is similar to morphine. The
Opioid analgesics: Key features recommended dose is 1.0 mg/ml or 2.0 mg/ml
• Opioids are good analgesics, but not good anti-inflammatory intramuscular or intravenous depending upon pain.
agents.
• Codeine is a standard opioid for oral administration. It may Combination of drugs
produce less analgesia than either aspirin (650 mg) or A meticulous approach is frequently exercised to
acetaminophen (600 mg). enhance the analgesic effects of oral medication by
• Pentazocine and related opioid have satisfactory analgesic combining two or more drugs having different
effect. Sedation is a common side effect. Respiratory mechanisms of action. A combination of ibuprofen and
depression effect may be similar to morphine. opioid is considered effective and safe analgesic.
• In addition to relieving pain, opioids may cause nausea,
vomiting and constipation.
Even diclofenac plus vitamin B has been more
• Overdoses lead to respiratory depression, and chronic use effective to relieve pain than diclofenac alone.
can culminate into physical dependence. The combination of acetaminophen/NSAID with an
• Opioid analgesics may decrease or inhibit salivary flow, opioid allows for increased analgesia because the drugs
contributing to the development of caries, periodontal act through dissimilar mechanisms. Aspirin-opioid
problems, oral candidiasis, etc. combinations are not preferred because of potential
NSAID-aspirin interactions.
The commonly used opioid-analgesics are:
The clinicians should be conscious about the benefits
i. Morphine: Morphine is a potent analgesic (visceral
and risks of the drug combination in the management
pain is relieved better than somatic pain). The
of pain.
associated features of pain are also relieved, such
as apprehension, fear, etc. The recommended dose Adverse effects of the combination
is 10–20 mg (2.0–10.0 mg intravenous) depending • Maximum pain relief is mostly accomplished by
upon the intensity of pain. The side effects of single agent. The combination usually leads to
morphine may be vomiting, respiratory depression, adverse effects.
urinary retention, etc. Morphine is not prescribed • Combination may lead to added side effects.
in renal diseases and hypothyroidism. • With opioids, the increased analgesia can be obtained
ii. Tramadol: Tramadol has weak opioid activity, by using a larger dose of a single drug; no use of
exhibiting less drug dependence, respiratory combining with other analgesics.
depression, as well as other side effects commonly • Combination of aspirin, phenacetin and caffeine (APC
associated with opioid use. Effective dose is 50– tablet) has been associated with kidney problems.
100 mg every six hours (maximum 400 mg/day).
Tramadol with acetaminophen is appropriate 3. Corticosteroids
option, especially for those patients who do not Steroids, also refer to as corticosteroids, are usually not
tolerate NSAIDs/opioid analgesics. used in endodontics because of its immunosuppressive
iii. Pentazocine (Fortwin): Pentazocine has weak effect (suppress the defence mechanism). It has been
antagonist and marked agonist actions. Sweating, established that a single oral dose or local use of steroids
tachycardia and rise in blood pressure are the
common side effects. Other adverse effects include
dry mouth, alteration in taste, urinary retention and
(intracanal medicament) might not have any specific
harmful effects. Two classes of enzymes, viz. Phospho-
lipase and cyclooxygenase are the basic target site, with
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 38 Essentials of Endodontics

intake of analgesics and anti-inflammatory drugs. pronounced (schizophrenic psychosis). The severity of
Phospholipase synthesizes arachidonic acid from adverse effects depends upon the duration and dose of
phospholipids. Cyclooxygenase synthesizes prosta- the steroid used.
glandins. Steroids are the group of drugs which func- Intraligamentary/intraosseous, intramuscular and
tion by inhibiting phospholipase A2, which reduces the oral administration of steroids have effectively reduced
production and concentration of prostaglandins and postendodontic pain. Steroids are effective in relieving
leukotrienes. pain associated with irreversible pulpitis and chronic
Corticosteroids refer to both glucocorticoids and inflammatory diseases. Intraoral intake of 6.0–8.0 mg
mineralocorticoid (both mimic hormone produced by of dexamethasone or 40 mg of methylprednisolone is
adrenal cortex). Mineralocorticoid is rarely used; gluco- sufficient as anti-inflammatory dose. Dexamethasone
corticoid is used as synonym with corticosteroid. is less potent than other corticosteroids, such as
The differences between glucocorticoids and triamcinolone.
mineralocorticoids are summarized in Table 4.2. Steroids have been used systemically to shorten
Glucocorticoids are frequently employed to reduce the course of nerve paraesthesia due to endodontic
or to eradicate inflammation. In addition, they can procedures. Intramuscular injections of steroids are also
inhibit the progression of inflammation, which prescribed for the treatment of sodium hypochlorite
ultimately leads to necrosis of pulp tissue. accidents.
The compounds of glucocorticoids and mineralo- Corticosteroids cause the adrenal glands to slow
corticoids and their dosage are tabulated in Table 4.3. down or stop the production of cortisol. Hence, they
Steroids should be used with caution in patients with cannot be discontinued abruptly. The adrenal glands
ulcerative colitis, peptic ulcer, diabetes, pregnancy and take some time to start producing cortisol again.
pyogenic infections. Tapering the dose of corticosteroids gradually allows
Glucocorticoids are contraindicated in patients with the body to start producing cortisol.
systemic fungal infections and those who are known
hypersensitive to the drug. Glucocorticoid therapy may Local application of steroids
lead to psychological disturbances, which can be mild Steroids have been widely used as an intracanal
and reversible (insomnia, euphoria/nervousness) or medicament. Hydrocortisone alone and in combination

Table 4.2 Difference between glucocorticoids and mineralocorticoids

Glucocorticoids Mineralocorticoids
• Glucocorticoids compounds are: Cortisol, cortisone, • Mineralocorticoids compounds are: Aldosterone, deoxy-
triamcinolone corticosterone
• Control carbohydrates, fat and protein metabolism • Control electrolyte and water balance of the body
• Secretion is under control of adenohypophyses • Secretion is under control of renin angiotensin system
• They are anti-inflammatory and anti-allergic • No such role
• Helpful in repairing injury and stress factor • Do not help repair and stress factor
• Reduce pain • Do not manage pain

Table 4.3 Glucocorticoid and mineralocorticoid—dosage and compound

Compound Dose
Glucocorticoids
Short acting • Hydrocortisone (cortisol) • 20 mg
Intermediate acting • Prednisolone • 5.0 mg
• Methylprednisolone • 4.0 mg
• Triamcinolone • 4.0 mg
Long acting • Dexamethasone • 0.75 mg
• Betamethasone • 075 mg
Mineralocorticoids • Deoxycorticosterone acetate • 2.5 mg (sublingual)

4
• Fludrocortisone (Florinef) • 0.2 mg
• Aldosterone • Not used clinically (necessary for regulation
of salt and water in the body)

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 Drugs used in Endodontics 39

with antibodies have shown favourable results. It has iv. Septomixine forte paste contains steroid and two
been established that the combination effectively antibiotics, neomycin and polymixin B sulphate.
reduces inflammation in the periapical areas. Both these antibiotics are not suitable against
The most commonly used steroid-antibiotic endodontic bacteria because of their inappropriate
combination for local applications are: spectra of activity. Neomycin is effective against
i. Ledermix is a combination of a steroid with an gram-negative rods, but ineffective against
antibiotic (1.0% triamcinolone (steroid) and 3.0% bacteroids, fungi, viruses, etc. Polymyxin B sulphate
demeclocycline (tetracycline in a polyethanol-glycol is bactericidal against gram-negative bacteria, but
base). It has been established that the dentinal not effective against gram-positive bacteria.
tubules are the major route of supply of the active The commonly employed anti-inflammatory drugs
components to the periradicular tissues than the are tabulated in Table 4.4.
apical foramen. The components of ledermix are
capable of diffusing through dentinal tubules and 4. Alternative Analgesic (Acupuncture)
cementum to reach periapical tissues. Demeclo- Acupuncture and laser acupuncture have been used
cycline is quite effective against susceptible bacteria successfully as an alternative form of analgesia.
in root canals. The effect of demeclocycline is Several studies have showed that acupuncture
achieved for all bacteria within the first day of treatment produced equivalent or better results than
application onto dentinal surface; however, this conventional treatments in the pain management in
effect may remain one-tenth after one week. dentistry.
Towards the cementum, the concentration of A study, wherein a laser acupuncture involving a
demeclocycline after one day is not sufficient to beam from a 2.8–6 mW Helium-Neon laser, was
eliminate most strains of endodontic bacteria. delivered and focused on the selected skin point of the
ii. Ledermix paste (1.0% triamcinolone and 3.0% patient. No other sedative or analgesic was adminis-
demeclocycline-calcium) and Ledermix cement tered before or during the operation. Out of total 610
patients studied, no one complained of any side effects.
(0.7% triamcinolone, 3.0% demeclocycline with
calcium based salts) are effective anti-inflammatory Factors affecting the prescription of analgesics
agents when used locally. Both cement and the base i. Age of the patient: As the age increases, less dose of
do not show any unfavourable side effects. analgesics are prescribed, especially in case of
iii. Ledermix and calcium hydroxide (50:50 mixture) has opioids (opioid sensitivity is common with
also been used as intracanal medicaments to eradicate advancing age). The regular dose of analgesics
endodontic micro-organisms from root canal walls. should be reduced by 50%.

Table 4.4 Commonly employed anti-inflammatory drugs

Drug Presentation Dosage
Acetylsalicylic acid Tablets—100 mg and 500 mg 1–2 tablet, 3–4 times/day
(maximum dosage 3 gm)
Ibuprofen Tablets—200 mg, 400 mg, 600 mg 1 to 2 tablets – 3–4 times/day
(Maximum – 320 mg/day)
Diclofenac Capsules/Tablets—50 and 100 mg 1 tablet (3–4 times/day )
Nimesulide Tablets—100 mg 1 tablet, twice daily
Betamethasone Tablets—0.5 and 2.0 mg 1 tablet (2–4 times daily)
Dexamethasone Tablets—0.5, 0.75 and 4.0 mg 0.75 to 15 mg/day (2–4 times daily)
Acetaminophen and Codeine Tablet 300 mg acetaminophen and 1–2 tablets (3–4 times daily)
30 mg codeine (Maximum 300 mg acetaminophen/
day and 300 mg codeine/day)
Tramadol Tablet 50 mg 1–2 tablets (3–4 times daily)
(Maximum 400 mg/day)

4
Tramadol and Acetaminophen 37.5 mg tramadol and 1–2 tablet (3–4 times daily)
325 mg acetaminophen (Maximum 3000 mg acetaminophen
400 mg tramadol)

t.me/Dr_Mouayyad_AlbtousH
 40 Essentials of Endodontics

ii. Paediatric patients: Ibuprofen oral suspension Table 4.5 Commonly reported endodontic microbes
(100 mg/5.0 ml) every four hours is the effective
Anaerobic bacteria
oral analgesic for children. The dose for 3 to 7 years
I. Gram-positive rods
old children is 5.0 ml (1 teaspoon) every six hours • Eubacterium spp.
and twice that for children 7 to 12 years old. • Propionibacterium propionicus
iii. Body size: The dosage is directly proportional to • Actinomyces spp.
body size.More the weight and circumference of • Filifactor alocis
the patient, more dose of the drug. • Pseudoramibacter alactolyticus
iv. Maintenance of effective drug concentration: The II. Gram-negative rods
patient should be directed to take the initial dose • Prevotella
as soon as feasible, followed by a fixed dose schedule • Porphyromonas
• Tannerella forsythia
for 3–5 days depending upon the procedure.
• Campylobacter rectus
v. Analgesics should be taken before onset of pain, • Fusobacterium spp.
followed by as per instructions of the operator. III. Gram-positive cocci
• Parvimonas micra
III. MANAGEMENT OF INFECTION • Peptococcus
It has been established that pulp-periapical infection IV. Gram-negative cocci
involves aerobic, facultative anaerobic and anaerobic • Veillonella
• Dialister spp.
micro-organisms. The dynamics of dental infections
warrants judicious use of antibiotics and that too as an V. Spirochetes
• Treponema denticola
adjunct along with other treatment modalities. Acute
• Treponema socranskii
lesions accompanied by pain and/or swelling, which • Treponema parvum
can be drained via root canal or soft tissues, do require
antibiotic therapy. Chronic infections generally do not Facultative anaerobic bacteria
require antibiotic therapy. Chronic alveolar infections I. Gram-positive rods
• Lactobacillus
are associated with pulpless teeth, which do not have
• Diphtheroids
blood supply reaching the pulp space. Following
II. Gram-positive cocci
systemic intake, the concentration of antibiotics
• Streptococcus viridans
reaching at the site (root canal) is negligible; therefore, • Beta haemolytic streptococcus
systemic antibiotic therapy is not beneficial. Antibiotics • Gamma haemolytic streptococcus
are chemical substances produced by either live micro- • Enterococcus spp.
organisms or synthetic process, aiming at inhibiting the III. Gram-negative cocci
growth and/or destroying the micro-organisms. • Neisseria dentiae
Odontogenic infection, including endodontic • Neisseria oralis
infections, are polymicrobial involving combination of
gram-positive, gram-negative, facultative anaerobes Indications
and strict anaerobic bacteria (Table 4.5). The indications of systemic use of antibiotics are:
It is hypothesized that microbial resistance to • Infection is bacterial and not viral (will respond to
antibiotics is increasing at an alarming rate. The major antibiotics)
cause of this problem is the use of antibiotics in an • Acute odontogenic and non-odontogenic infections
inappropriate manner, leading to dominance of • As prophylaxis in patients with infective endo-
resistant micro-organisms. When bacteria become carditis and replacement therapy
resistant to antibiotics they may transfer resistance
• As prophylaxis to avoid or minimize systemic spread
genes from antibiotic–resistance to antibiotic–
of infection
susceptible micro-organism.
Endodontic sensitivity of endodontic bacteria is Myths of using antibiotics
gradually decreasing with growing number of resistant 1. Antibiotics cure patients: Antibiotics are not curative;
strains (Porphyromonas spp. and Prevotella spp.). except in immunocompromised patients. They assist
Antibiotics should be employed only for the in the re-establishment of the balance between the

4 management of active infectious disease or the

prevention of metastatic infection such as infective
endocarditis in medically high-risk patients (Table 4.6).
host’s defence and the invasive agents.
2. Antibiotics are substitutes for surgical intervention:
Antibiotics do not provide an appropriate substitute

t.me/Dr_Mouayyad_AlbtousH
 Drugs used in Endodontics 41

Table 4.6 Antibiotics as an adjunct in endodontic lesions

• Acute apical periodontitis (pain on percussion/biting) • No need of antibiotics
• Acute apical abscess (periapical sinus) • No need of antibiotics
• Pulp necrosis (non-vital tooth) • No need of antibiotics
• Irreversible pulpitis (pain) • No need of antibiotics
• Apical abscess with systemic involvement (swelling with fever, • Antibiotics required
lymphadenopathy, etc.)
• Persistent infections (chronic exudate) • Antibiotics required
• Any lesion with medically compromised patient (systemic • Antibiotics required
diseases causing impaired immunologic functions)

for removal of the source of the infection. When the 8. All types of infections require a complete course of
clinical situation does not allow for immediate antibiotic therapy: A common belief is that prolonged
curative treatment, an appropriate antibacterial antibiotic therapy is necessary to prevent ‘rebound’
therapy can be implemented. infections. Orofacial infections usually do not
3. When and which antibiotic to be used: The knowledge ‘rebound’ if the source of the infection is eradicated.
of invading micro-organisms and their susceptibility Patients placed on antibiotic therapy for an orofacial
establish the choice of antibiotic. infection should be evaluated periodically.
4. Antibiotics increase the host defence: A few studies have
observed that antibiotics increase the host's defence Classification
to infection. Various postulates are: Antibiotics are mainly identified as of two types:
• Antibiotics that can penetrate into the mammalian (i) those that kill bacteria rapidly and (ii) those that kill
cell (erythromycin, tetracycline, clindamycin and bacteria slowly by retarding bacterial protein synthesis.
metronidazole) are more likely to affect the host The faster-killing antibacterial agents are preferred in
defence endodontic infections.
• Tetracycline may suppress white cell chemotaxis The antibiotics are classified as:
• Most antibiotics (except tetracycline) do not a. Beta-lactam antibiotics
depress phagocytosis i. Benzyl-penicillin (penicillin G)
• T- and B-lymphocyte transformation may be ii. Phenoxy-penicillin (penicillin V)
depressed by tetracycline. iii. Penicillinase-resistant penicillin/anti-staphylo-
5. Multiple antibiotics are superior to a single antibiotic: It coccal-penicillin (oxacillin)
is often assumed that a combination of antibiotics is iv. Aminobenzyl-penicillin (ampicillin, amoxicillin)
superior to a single antibacterial agent. The primary
v. Ureido-penicillin (broad-spectrum penicillin)
indication for combined antimicrobial therapy is a
(Mezlocillin, Piperacillin)
severe infection; major consequences may ensue if
b. Aminoglycosides (streptomycin, gentamicin,
antibiotic therapy is not instituted immediately.
amikacin)
6. Bactericidal agents are always superior to bacteriostatic
c. Nitroimidazole (metronidazole)
agents: Bactericidal agents are required for patients
with impaired host defence; however, bacteriostatic d. Macrolides (erythromycin, clarithromycin,
agents are equally effective when the host’s defence azithromycin)
against infections are unimpaired. Post antibiotic e. Lincosamide (clindamycin)
effects are more persistent with bacteriostatic agents f. Quinolones (norfloxacin, ofloxacin, ciprofloxacin,
(erythromycin, clindamycin) than with bactericidal levofloxacin, moxifloxacin)
agents (beta-lactamase). g. Cephalosporin (first generation—cefazolin, cefadroxil;
7. Antibiotic dose and duration of therapy for endodontic Second generation—cefuroxime, loracarbef; Third
infections: The proper dose and duration of therapy and fourth generation—cefotaxime, ceftriaxone,
depends upon the microbial pathogen(s) suspected ceftazidime)
in the infection lesion. In dentistry, the prescription Penicillin, cephalosporin, and metronidazole are the
of antibiotics is empirical, as exact nature of
pathogens is not known (broad spectrum antibiotics
are prescribed on presumptive basis).
bactericidal antibiotics commonly used against
endodontic micro-organisms. The first two kill by
integrating and weakening the cell wall; whereas, the
4

t.me/Dr_Mouayyad_AlbtousH
 42 Essentials of Endodontics

latter impedes DNA of the bacterial cell. Both are plus one day after to allow the drug to be eliminated
effective against actively growing organisms. properly.
Antibiotics that fight bacteria by slowing their protein The half-life of metronidazole is 8–10 hours and the
synthesis (bacteriostatic antibiotics) are generally not recommended dose is 500 mg thrice a day. Side effects
advised. include an unpleasant, metallic taste and brown
The commonly prescribed antibiotics in endodontic discoloration of the urine. Metronidazole has also been
infections are: associated with blood dyscrasias and hypersensitivity
reactions.
i. Penicillin
Penicillin, having a short half-life (about one hour) is a iv. Macrolides (Erythromycin, Clarithromycin,
narrow-spectrum antibiotic. The injectable penicillin is Azithromycin)
Procaine penicillin; whereas, Penicillin V (Phenoxymethyl Erythromycin, clarithromycin and azithromycin are
penicillin) is given by oral route.If penicillin is also called macrolides because of their large molecule.
prescribed by oral route, the patient is instructed to take Erythromycin kills bacteria by slowing down the
the required dose one hour before meal. Patients with synthesis of bacterial protein. Erythromycin is the drug
compromised kidney functions are given reduced dose, of choice for patients allergic to penicillin. The
since it is excreted through kidney. If the patient is macrolides kill many gram-positive bacteria but have
undergoing hemodialysis, the dose is fixed in a limited spectrum for gram-negative bacteria. Use of
consultation with the nephrologist. Penicillin is not well erythromycin may lead to gastric cramps; however,
absorbed from intestinal tract (70% wastage), with allergic reactions are rare. The wider-spectrum new
diarrhea as a frequent side effect. macrolides, azithromycin and clarithromycin, are
Penicillin is generally non-toxic. If the patient is not effective for endodontic infections.
allergic, there are no side effects from over-dosage. It should be noted that clarithromycin is metabolized
Amoxicillin is considered the drug of choice because by both the liver and the kidney. Caution is warranted,
of its better absorption from the gut. It is preferred for in patients with compromised kidney or liver, because
orofacial infection because it is readily absorbed and the half-life of the drug is prolonged (the half-life of
can be taken with food. One major disadvantage of erythromycin is in the range of 1 to 2 hours; whereas,
using penicillin is the possibility of allergic reactions clarithromycin’s half-life is 6 hours, and azithromycin
(may be in the form of stomach upset and diarrhea). has a remarkable 40-hour half-life). The recommended
The recommended dose of penicillin is 1.2–2.4 IV/ dose of azithromycin is 500 mg daily.
24 hours intramuscularly and amoxicillin is given orally
v. Clindamycin
as 500 mg thrice a day.
Clindamycin is frequently used in endodontic
ii. Cephalosporins infections, especially for patients allergic to penicillin.
Cephalosporins are improved version of penicillin with It is rapidly and completely absorbed and has a good
the ability to kill stubborn infections. Cephalosporins spectrum of killing endodontic pathogens. Patients
are classified as fuse generation; first-generation being treated with clindamycin who experience
cephalosporins are the most effective in endodontic diarrhea or any gut problem should immediately be
infections, since they kill most of the endodontic referred to their physician for evaluation.
pathogens; whereas, second- and third-generation The average half-life of clindamycin is about three
cephalosporins are preferred for respiratory infections. hours. The recommended dose of clindamycin is
300 mg thrice daily or 600 mg intravenous injection.
iii. Metronidazole The side effects include gastrointestinal problems,
Metronidazole is a preferred bactericidal drug because which may become fatal due to development of pseudo-
of its fast action. It attacks the bacteria’s DNA. This drug membranous colitis.
is more suitable against obligate anaerobe and not
against facultative bacteria/aerobes. Metronidazole is vi. Tetracycline (Doxycycline)
often used in combination with another antibiotic, Tetracycline is least affected by heavy metal ions,
usually amoxicillin, to combat the stomach ulcer- such as calcium; so the patient does not have to avoid
causing bacteria, Helicobacter pylori. This combination dairy products. Tetracycline has the ability to kill the

4 of two fast-killing drugs help in eradicating endodontic

infections. Patients taking metronidazole should be
cautioned not to take alcohol during days of drug intake
broadest spectrum of microbes. Half-life of most
tetracycline is about 10–16 hours, allowing dose twice
daily.

t.me/Dr_Mouayyad_AlbtousH
 Drugs used in Endodontics 43

Tetracycline may cause staining of developing teeth Antibiotic Prophylaxis

as they bind to calcium during formation of teeth and Systemic diseases compromising the immune system
bones. Their use should be avoided in children and preg- mainly call for consideration of prophylactic antibiotics.
nant women. A rare side effect is phototoxicity, where The goal of antibiotic prophylaxis is to prevent clinical
exposure to the sun causes severe sunburn or rash.
infection by destroying small numbers of bacteria
vii. Sulfa drugs present before or introduced during treatment. Oral
Sulfa drugs are frequently used for urinary tract bacteria, especially streptococci can cause heart and
infections. Sulfa drugs cannot kill rapidly because they artificial joint infections.
compete with a precursor in the bioformation of folic The protocol proposed by the American Heart
acid, which many bacteria cannot obtain from other Association states that antibiotics must be administered
sources. Sulfa drugs are the slowest and poorest of one hour (oral route) or 30 minutes (intravenous route)
bacteriostatic antibiotics. They are not generally used before the procedure. The antibiotics of choice are
in endodontic infections. amoxicillin 2.0 grams. Clindamycin 600 mg is preferred
for patients allergic to penicillin.
Use of antibiotics: Key features
The prophylaxis regime is tabulated in Table 4.8.
• Penicillin is the antibiotic of choice for endodontic infections
due to its effectiveness in polymicrobial infections, low toxicity The procedures for which antibiotic prophylaxis is
and low cost (only problem of allergic reactions). recommended are:
• Amoxicillin and amoxicillin plus clavulanic acid demonstrated • Periodontal procedures (periodontal surgery, deep
a higher antibacterial effectiveness than penicillin. curettage, scaling and root planing etc.)
• Clindamycin is the antibiotic of choice for patients allergic to
penicillin. • Implant placement
• Metronidazole demonstrated the greatest amount of bacterial • Difficult extractions
resistance and is only effective against anaerobes; should not • Replantation of avulsed teeth
be used alone (metronidazole in combination with amoxicillin
is preferred). • Endodontic surgery
• The host defence may be affected by antibiotics that easily • Intraligamentary/intraosseous injections
penetrate into the mammalian cell; whereas, bactericidal, non- • Postoperative suture removal (selected cases)
penetrating agents (penicillin and cephalosporin) affect the
least. • Prophylactic cleaning of teeth where bleeding is
anticipated
The commonly used antibiotics, their dosage and Flowchart 4.1 summarizes protocol of drugs used in
side effects are tabulated in Table 4.7. endodontics.

Table 4.7 Commonly used antibiotics: Dosage and side effects

Antibiotic Route of administration Dose Side effects
Penicillin Oral
Intramuscular/intravenous 1000 mg initially followed by Hypersensitivity reactions, gastric
500 mg every 6 hourly 1.2–2.4 problems
million IU/24 hours intramuscular
Amoxicillin Oral 500 mg/8 hours and 1000 mg/
12 hours
Combination of 250 mg amoxicillin Diarrhea, nausea, hypersensitivity
+ 125 gm clavulanic acid reactions
Amoxicillin-clavulanic Oral/intravenous 500–875 mg/8 hours orally Diarrhea, nausea, candidiasis,
acid (Augmentin) 1000–2000 mg/8 hours intravenous hypersensitivity reactions
Clindamycin Orally/intravenous 300 mg/8 hours orally 600 mg/ Pseudomembranous colitis
intravenous
Gentamicin Intramuscular/intravenous 240 mg/24 hours Ototoxicity/Nephrotoxicity
Ciprofloxacin Oral 500 mg/12 hours Gastrointestinal disorders
Azithromycin Oral 500 mg/24 hours Gastrointestinal disorders
Metronidazole Oral 500–750 mg/8 hours Anesthesia/paresthesia of the limbs,
incompatible with alcohol intake 4

t.me/Dr_Mouayyad_AlbtousH
 44 Essentials of Endodontics

Table 4.8 Antibiotic prophylactic regimens for dental procedures

Route of administration Antibiotic Dose
Adult Children
Oral Amoxicillin 2.0 g 50 mg
Oral route not feasible Ampicillin 2.0 g intramuscular/intravenous 50 mg intramuscular/
(intramuscular/intravenous intravenous
route) Cefazolin 1.0 g intramuscular/intravenous 50 mg intramuscular/
intravenous
Allergic to penicillin/ Cephalexin 2.0 gm 50 mg/kg
ampicillin (oral route) Clindamycin 600 mg 20 mg/kg
Azithromycin/Clarithromycin 500 mg 15 mg/kg
Allergic to penicillin/ampicillin Cefazolin 1.0 Gm IV, IM 50 mg
(oral route not feasible) Clindamycin 600 mg 20 mg

Flowchart 4.1: Protocol of drugs used in endodontics

Antibiotic Use: Risk and Precautions despite the potential risk (aminoglycosides,
Various clinical conditions warrants use of antibiotics; tetracycline, carbamazepine, lorazepam). (Oral
however, these should be cautiously and judiciously contraceptives may be rendered ineffective by penicillin
used, especially in certain systemic conditions, such as: and erythromycin. The patient taking these medicines
a. Pregnancy: Four level of risk during pregnancy has should be informed that the contraceptive will be
been established: ineffective for the duration and also 10 days after its use).
i. Category 1: No evident risk factor (no antibiotic b. Kidney failure: The dose of the antibiotics should be
corresponds to this group). A few studies reported adjusted according to the level of creatinine clearance.
no teratogenic effect with the use of penicillin and
erythromycin). c. Liver failure: Antibiotics which metabolized in liver,
should be restricted. The dose of erythromycin,
ii. Category 2: No effect in animals (azithromycin,
clindamycin and metronidazole should be adjusted
penicillin V, amoxicillin, erythromycin, metronida-
when administered to patients with liver failure.
zole).
iii. Category 3: Effect not established in either animals or The side effects of systemic antibiotics are:
human studies (morphine, atropine, corticosteroids, • Hypersensitivity reaction
• Alteration of the bacterial flora
4
clarithromycin, fluoroquinolones and sulfa drugs).
iv. Category 4: Teratogenic effects upon the fetus; • Toxic to host cells
however, the potential benefits may be acceptable • Development of resistant strains

t.me/Dr_Mouayyad_AlbtousH
 Drugs used in Endodontics 45

Drug Resistance An organism can also acquire resistance to an anti-

Drug resistance refers to unresponsiveness of a micro- biotic to which it was previously sensitive. This can be
organism to an antimicrobial activity; synonymous with due to chance mutation in the genetic material of the
the phenomenon of tolerance. cell, or the acquisition of resistance genes from other
Resistance can be natural or acquired. drug-resistant cells.
• Natural resistance: Some microbes lack the metabolic The main mechanisms by which micro-organisms
process or the target site which is affected by the exhibit resistance to antimicrobials are:
particular drug (for example, gram-negative bacilli are • Micro-organisms destroying/inactivating/modifying
normally unaffected by penicillin). the drug (enzymatic deactivation of penicillin G in
• Acquired resistance: The resistance developed by an some penicillin-resistant bacteria through the
organism due to the use of an antimicrobial over a production of β-lactamases).
period of time (for example, gonococci quickly • Micro-organisms making the drugs impermeable/
develops resistance to sulphonamides as compared alteration of target site (reduced drug accumulation
to penicillin. Staphylococci and tubercle bacilli by decreasing drug permeability and/or increasing
develop rapid resistance to penicillin). active efflux (pumping out) of the drugs across the
Antibiotic resistance can be microbiological or cell surface).
clinical. Microbiological resistance exists when an • Micro-organisms facilitating drug tolerance/
organism possesses any resistance mechanism; alteration of metabolic pathway (some sulfonamide-
whereas, clinical resistance is the failure to achieve a resistant bacteria do not require para-aminobenzoic
concentration of antimicrobial that inhibits the growth acid for the synthesis of folic acid and nucleic acids;
of the organism in a particular tissue or fluid. instead, they may utilize preformed folic acid).
Multiple drug resistance or multi-resistance is Prevention of drug resistance
antimicrobial resistance shown by a species of micro- The following features help prevent the drug resistance:
organism to multiple antimicrobial drugs (resistant • Inadequate/prolonged use of antimicrobials should
to multiple antifungal, antiviral, and antiparasitic be avoided.
drugs).
• Use the appropriate antimicrobial for an infection
Mechanism of Drug Resistance (no antibiotics for viral infections).
• Identify the causative organism.
Bacterial resistance may be developed by mutation of
the DNA molecule or can be acquired from other • Select an antimicrobial which targets effectively to
bacteria by DNA transfer (from one species to another). the specific organism (do not rely on broad-spectrum
In addition to enzymatic destruction of antibiotic antibiotics).
molecules, as with-lactamase, bacteria may get • Organisms notorious for developing resistance must
resistance by not allowing an antibiotic to pass through be treated accordingly.
the cell membrane. Another situation may also lead to • Complete an appropriate duration of antimicrobial
resistance when the bacteria can pump out antibiotic treatment (not too short and not too long).
molecule faster than it can enter. • Use the correct dose for bacterial eradication (sub-
Bacteria generally pass on their resistance genes to therapeutic dose may lead to resistance).
their offspring. In any clinical situation, it is mandatory • Use combination of antimicrobials, if prolonged
to limit antibiotic therapy; the patient should get benefit treatment is required.
from the antibiotics and should not facilitate developing
‘resistance’ amongst the micro-organisms. Injudicious use of Antibiotics (Antibioma)
Antimicrobial activity can be described in terms of Antibiotic resistance has been an established pheno-
minimum inhibitory concentration. Bacteria can be menon; overdose of antibiotics may contribute to
described as ‘sensitive’, ‘intermediate susceptible’ or development of resistance. Various studies have
‘resistant’, depending on the intensity of drug required reported resistance of Streptococcus viridians for
to inhibit growth of the micro-organism. The resistance antibiotics such as clindamycin and macrolides. Broad
is related to the serum concentration of a drug that is spectrum antibiotics are generally used in endodontics.
achieved at the site of infection/tissues. Serum Injudicious use of antibiotics for self-limiting infection
concentration in tissues might not be reproducible
between patients or even in the same patient at different
sites.
is a common feature.
‘Antibioma’ is a common sequelae of injudicious use
of antibiotics without concentrating on the underlying
4

t.me/Dr_Mouayyad_AlbtousH
 46 Essentials of Endodontics

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Curd F. An analysis of current analgesic preferences for endo- dentistry. J. Dent. Allied Sci.: 2015; 4:19–24.
dontic pain management. J. Endod.: 2006; 32:1146–1154. 41. Segura-Egea JJ, Gould K, Sen BH, Jonasson P, Cotti E, Mazzoni
27. Miles M. Anesthetics, analgesics, antibiotics and endodontics. A, Sunay H, Tjaderhane L and Dummer PMH. Antibiotics in
Dent. Clin. North Am.: 1984; 28:865–82. endodontics: a review. Int. Endod. J.: 2016; 1–16.
28. Mohammadi Z. Systemic and local applications of steroids 42. Selden HS. Patient empowerment. A strategy for pain
in endodontics: an update review. Int. Dent. J.: 2009; 59:297– management in endodontics. J. Endod.: 1993; 19:521–523.
304. 43. Silva NM. Systemic medication applied to endodontic
29. Nogueira BML, Silva LG, Mesquita CRM, Menezes SAF, treatment: a literature review. RSBO: 2014; 11:293–302.
Menezes TOA, Faria AGM and Porpino MTM.: Is the use of 44. Sivakumar NR. Steroids in root canal treatment. Int. J. Pharm.
dexamethasone effective in controlling pain associated with Pharma. Sci.: 2014; 6:17–19.
symptomatic irreversible pulpitis? A systematic review. J. 45. Stewart PS and Costerton JW. Antibiotic resistance of bacteria
Endod.:2018; 1-8. in biofilms. Lancet: 2001; 14:135–138.
30. Pak JG and White SN. Pain prevalence and severity before, 46. Tong DC and Rothwell BR. Antibiotic prophylaxis in dentistry.
during and after root canal treatment: a systematic review. J. A review and practice recommendation. JADA: 2000;
Endod.: 2011; 37:429–38. 131:366–374.
31. Pallasch TJ. Antibiotic prophylaxis. Endod. Topics: 2003; 47. Vera JRM and Gomez-LusCentelles ML. Antimicrobial
4:46–59. prophylaxis in oral surgery and dental procedures. Med. Oral
32. Parirokh M and Abbott PV. Various strategies for pain-free Patol. Circ. Buccal.: 2007; 12:44–52.
root canal treatment. Iran. Endod. J.: 2014; 9:1–14. 48. Walton RE and Chiappinelli J. Prophylactic penicillin: effect
33. Paxton K and Thome DE. Efficacy of articaine formulations: on post-treatment symptoms following root canal treatment of
quantitative reviews. Dent. Clin. North Am.: 2010; 54:643– asymptomatic periapical pathosis. J. Endod.:1993; 19:466–470.
653. 49. Wong JK. Adjuncts to local anesthesia: separating fact from
34. Pochapski MT, Santos FA, Andrade ED and Sidney GB. Effect friction. J. Can. Dent. Assoc.: 2001; 67:391–397.
of pre-treatment dexamethasone on post-endodontic pain. 50. Zahed M. Systemic, prophylactic and local applications of
Oral Surg., Oral Med., Oral Path., Oral Radiol. Endod.: 2009; antimicrobials in endodontics: an update review. Int. Dent.
108:790–795. J.: 2009; 59:175–186.

t.me/Dr_Mouayyad_AlbtousH
Chapter
5
Diseases of the
Dental Pulp

Dental pulp is the soft connective tissue of mesenchymal The features are:
origin located in the center of the tooth. It is situated in • Pulp can produce reparative dentin, which protects
an enclosure called pulp chamber in the crown and root pulp from injury and other irritants.
canal in the root covered with dentin. It contains • Pulp is surrounded by hard tissue (the dentin), which
odontoblasts, fibroblasts and defense cells. The does not allow the usual swelling associated with
fibroblasts represent the largest cell population, and the acute inflammatory process.
appear as both inactive and active cells; the latter • Pulp lacks collateral circulation (few vessels supply
producing the intercellular substances and collagen the pulp through the apical foramen and another few
precursors. The undifferentiated mesenchymal cells enter through lateral/accessory canals); compro-
may replace odontoblasts as well as defense cells, and mising healing capacity.
assume their functions; designated as replacement cells. During inflammation, exudates leave the vessels and
The primary function of the pulp is ‘formative’; it gives raise the interstitial pressure. Since the fluid is not
rise to odontoblasts that not only form dentin but compressible and there is little room for edema, this
interact with dental epithelium to initiate the formation may cause local tissue hypoxia leading to localized
of enamel. Pulp also provides several secondary functions necrosis. It is established that increase of pressure in
related to tooth sensitivity, hydration, defense, etc. one area does not affect the other areas of pulp. The
Certain anatomical features make the pulp a unique local inflammation results in increased tissue pressure
tissue which may be responsible for its vulnerability to in inflamed area and not the entire pulp cavity. Limited
various physical, chemical, and bacterial insults. Pulp increase in pressure within affected pulpal area is
reacts to these irritants as do other connective tissues. explained by the following features:
Pulpal injury may result in inflammation and • Increased pressure in inflamed area leads to net
subsequent cell death. The degree of inflammation is absorption of interstitial fluid from adjacent
proportional to the intensity and severity of the capillaries in uninflamed tissues.
irritants. Minor injuries, such as incipient caries or • Increased interstitial pressure lowers the trans-
shallow cavity preparations, cause little or no capillary hydrostatic tissue pressure difference, thus
inflammation in the pulp. In contrast, deep caries or limiting the filtration process.
extensive operative procedures, usually produce severe • Increase in interstitial fluid pressure results in
inflammatory changes. Depending on the severity and increased hydrostatic drainage and keep the pulpal
duration of the insult coupled with the host responses, volume almost constant.
the pulpal response ranges from transient inflammation • Break in endothelium of capillaries facilitates
to necrosis. These changes are usually very slow, exchange mechanisms.
without pain and remain unnoticed, till symptoms Continued spread of local inflammation may lead
warrant the patient. to total necrosis. Earlier, it was thought that the pulp
responded initially by acute inflammation, followed by
PULPAL INFLAMMATION chronic inflammation, regardless of the etiologic factor.
The process of inflammation in the pulp is basically It is established that the initial response might be due
the same as in other connective tissues of the body; to chronic inflammation (most of the irritants progress
however, certain features, unique of its kind in pulp, slowly; however, rapid irritation by operative
tend to alter the course of this response. procedures lead to acute inflammation).

48

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 Diseases of the Dental Pulp 49

Entry of Irritants to Pulp A. Physical

Potential antigens include bacteria and their degrada- a. Mechanical
tion by-products, which directly or via dentinal tubules,
The mechanical injuries leading to pulp diseases are:
can initiate inflammatory reactions. Irritations from any
source enter the pulpal tissue through the following i. Traumatic injuries
portals: Traumatic dental injuries may occur at any age;
i. Direct extension through the dentinal tubules, as however, mostly young children are affected. The
in case of caries or chemicals placed on the dentin. injuries can be because of fights, sports, automobile
ii. Extension of periodontal disease into the pulp; in accidents, house hold accidents, compulsive bruxism,
deep periodontal pockets, exposing the lateral nail biting and opening bobby pin with teeth (Fig. 5.1).
canals or apical foramen to the oral environment, Mainly incisors are affected, may be primary or
may lead to total pulp necrosis. permanent (fractured or displaced incisors).
iii. Extension by process of anachoresis, the localization The severity of trauma and degree of apical closure
of blood-borne bacteria within the pulp. This at the time of trauma are important factors in recovery
explains why some pulps become necrotic when of the pulp. Mild to moderate trauma or teeth with
there is no apparent etiologic factor. immature apex have a better chance of pulpal survival.
Completed root formation or severe injuries may lead
iv. In addition to nonspecific inflammatory reactions,
to irreversible changes. The dental procedures, if not
immune responses may also initiate and perpetuate
carried out properly, may injure the pulp. Such
pulpal diseases.
inflammation is usually reversible; however, if not
managed on time may lead to irreversible changes.
CAUSES OF PULP DISEASES
ii. Mechanical irritants
The causes of pulp diseases are categorized as:
The mechanical irritants are generally carried by
A. Physical occlusal trauma, curettage of deep periodontal pockets
a. Mechanical and use of dull burs/points during cavity preparation.
i. Traumatic injuries Continuous cavity preparation using heavy pressure
ii. Mechanical irritants also act as mechanical irritant. Irritation because of
mechanical separator and orthodontic movements also
iii. Pathologic/physiologic wear
affect pulpal tissues.
iv. Cracked tooth syndrome The damage to the subjacent odontoblast cells in the
v. Barodontalgia pulp tissue needs to be avoided. The number of dentinal
vi. Lasers tubules per unit surface area and their diameter
vii. Restorations increases as we move closer to the pulp. As a result,
dentinal permeability close to the pulp is higher than
b. Thermal near the dentinoenamel junction or cementodentinal
i. Cavity preparation junction. Therefore, potential for pulpal damage
ii. Exothermic setting of cements increases as more dentin is removed during the cavity
iii. Thermal conduction through restorations
iv. Polishing heat
c. Electrical
i. Galvanic current from dissimilar fillings

B. Chemical
i. Phosphoric acid, acrylic monomer, etc.
ii. Dental erosion (acids)

C. Bacterial
i. Toxins associated with caries
ii. Direct pulp invasion from caries/trauma
iii. By blood borne microbes (anachoresis) Fig. 5.1 Fracture of maxillary incisors due to trauma
5

t.me/Dr_Mouayyad_AlbtousH
 50 Essentials of Endodontics

preparation. The most critical factor is the ‘remaining condition can be experienced either during flight or
dentin thickness’. Minimal effects are transmitted to the during a test run in a decompression chamber.
pulp if the remaining dentin thickness is 2.0 mm or Barodontalgia can be observed in altitude of over 5000
more. Pulp damage is considered proportional to the feet, but attitude of 10,000 feet and above lead to
amount of dentin removed and also the depth of symptoms. A tooth with chronic pulpitis may not
removal as well. produce any symptoms at ground level but it may cause
pain at high altitude because of low atmospheric
iii. Pathologic/physiologic wear
pressure. Giving a layer of cavity varnish or liner under
Dental pulp has got an excellent reparative power of the restoration helps to prevent this problem. Although
laying down dentin reacting to clinical situation; the process of barodontalgia is not properly
however, in some conditions, the reparative capacity understood, it may be related to pulpal hyperaemia or
of the pulp does not keep pace with the stimulus. In to the gases which are trapped in the teeth following
such conditions, the pulp shows irreversible damage; root canal treatment.
for example, a severely attritioned mandibular incisor
may lead to pulpal necrosis. vi. Lasers
The abrasion caused by the dentifrices may also be Lasers, especially during cavity preparation may lead
so severe causing pulp exposure. Night clenching or to inflammation in pulp. The production of heat and
bruxism and occlusal trauma may also show similar rise in the pulpal temperature can damage the pulp.
involvement of the pulp. Electron microscopic studies have shown disruption
and degeneration of pulpal peripheral nerve endings,
iv. Cracked tooth syndrome subsequently leading to reduced sensitivity.
Incomplete hair line crack through the body of the tooth
(cracked tooth syndrome) may sometime cause severe vii. Restorations
pain. The patient usually complains of pain, ranging Pulpal pain and subsequent pulp tissue changes may
from mild to excruciating at the initiation and release result following the insertion of metallic restoration like
of biting pressure. The most common and reliable gold foil and silver amalgam restoration. Other
diagnostic method is to reproduce the pain. When the restorations viz. silicate cements and zinc oxide eugenol
patient bites on a cotton applicator, rubber wheels or cements may produce inflammatory reaction in pulp.
tooth slooth, the fractured fragments may separate and Glass-ionomer cements and/or composite resins,
the pain may be reproduced (Fig. 5.2a and b). Magnified especially in deep cavities, have also shown pulpal
examination of the crown of the tooth may disclose an changes.
enamel crack; using operating microscope or
transilluminating the tooth by using fiberoptic light. b. Thermal
The incomplete fracture of enamel and dentin usually The thermal injuries are usually due to following causes:
produces mild pain; eventually pain becomes severe
i. Cavity preparation
when the fracture line touches the pulp.
The inflammation following cavity preparation may
v. Barodontalgia (Aerodontalgia) range from reversible to irreversible changes. It is
The pain experienced by a patient in a recently restored established that deeper the preparation, more extensive
tooth during low atmospheric pressure usually at high is the pulpal inflammation. The main reason is heat
altitude is called Barodontalgia (aerodontalgia). This produced by cutting/grinding instrument during

5
a b

Fig. 5.2 (a) Tooth slooth (a small pyramid shaped plastic bite block with a small concavity at the apex of the pyramid).
(b) Patient biting on tooth slooth

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 Diseases of the Dental Pulp 51

cavity preparation, especially if used without coolant. B. Chemical

The generated heat may cause the irreparable damage Chemical causes of pulp injury are probably less
to the pulp. Constant drying with air syringe/chip common. Earlier, arsenic in silicate cement powder and
blowing may also contribute to pulp inflammation and the use of desensitizing paste containing paraformal-
subsequently the necrosis, particularly in a stressed pulp. dehyde accounted for pulp necrosis; however, these
The features contributing rise in the pulpal temperature materials are no longer in use. It is established that most
are: restorative materials, if properly used, do not cause any
• Amount of force applied by the operator. damage to the pulp. Some of the materials may
contribute to pulpal inflammation; however, the initial
• Size, shape and condition of the cutting tool.
inflammatory reaction may subside with time.
• The speed (revolution per minute) of cutting tool. A few restorative materials may cause chemical
• Continuous time of usage. insult to the pulp, such as:
ii. Exothermic setting of cements • Phosphoric acid of zinc phosphate cement.
• Acid etching with 37% ortho-phosphoric acid
Certain cements, viz. zinc phosphate cements create
• Calcium hydroxide, owing to its high alkaline pH,
exothermic reaction during setting; the heat so
produced will lead to changes in pulp tissues. produces low grade irritation.
• Eugenol in zinc oxide eugenol cement
iii. Thermal conduction through restorations • Dental erosions, if continued, may also lead to pulp
Metallic restorations are positive conductor of heat. involvement.
Restoration like silver amalgam and gold foil, especially The remaining dentin thickness plays a crucial role
if close to the pulp, may conduct temperature changes in determining the effect of chemicals on the pulp. The
to the pulp and cause irreparable damages. Sudden thickness of remaining dentin is inversely proportional
temperature changes because of ice cream/coffee, tea, to the effect; more the thickness, less detrimental effect.
etc. may contribute to pulpal damage. Remaining Certain restorative materials are hygroscopic; absorb
dentin thickness under the metallic restoration is the moisture from the dentin, leading to its desiccation. For
key factor in determining the type of inflammatory example, cavit placed over thin dentin causes
changes in the pulp. Dentin is the natural thermal desiccation.
insulator which protects the pulp from thermal insults.
The procedures which lead to removal of protective C. Bacterial
layer of the dentin over the pulp, lead to pulpal The role of bacteria in causing pulp inflammation is
inflammation and subsequent changes. well established. The ingress of bacteria in the
iv. Polishing heat mechanically exposed pulp determines the prognosis
of vital pulp therapy.
The abrasive instruments, because of their frictional
The bacteria may enter the pulp following different
working produce heat, especially when used without
ways as:
coolants. The routine polishing of the restoration
produces enough heat, which can be detrimental to • Caries
pulp. Even interproximal finishing and polishing of the • Fracture
restorations using the abrasive finishing strips without • Tooth anomalies (dens invaginatus and dens
a constant air coolant may also cause similar damage evaginatus)
to the pulp. • Palato-gingival or radicular lingual groove
• Infection caused via periodontal pocket/periodontal
c. Electrical abscess
Two chemically dissimilar metallic restorations, like • Haematogenic
silver amalgam and cast gold restoration, when come The micro-organisms present in the carious lesion
in contact in presence of saliva, produce electro- are the main sources of irritation of the dental pulp.
galvanism or galvanic shock. As both the restorations Bacterial invasion from a carious lesion and/or
are wet with saliva, an electric couple exists, with a traumatic exposure frequently cause pulp inflamma-
difference in potential between the dissimilar tion. Bacterial invasion is also possible through lateral
restorations. When two restorations come in contact,
the potential is suddenly short circuited, resulting in
acute changes in pulp and subsequent pain.
canals, or periodontal/periapical blood vessels. Once
bacteria invade the pulp, the damage is almost
irreparable. The species of bacteria recovered from
5

t.me/Dr_Mouayyad_AlbtousH
 52 Essentials of Endodontics

inflamed or infected pulps are many and varied in Flowchart 5.1 Pulp reactions to various irritants
nature. Although lactobacilli (acidogenic micro-
organism) are commonly found in carious dentin, they
are seldom recovered from the pulp because of their
low degree of invasiveness. Micro-organisms need not
be present in the pulp to produce inflammation; the
degradation by-products of bacteria are sufficiently
irritating to cause inflammatory reaction.
The bacteria most often recovered from infected pulps
are streptococci and staphylococci; however, many other
micro-organisms (mostly anaerobes) have been isolated
from the infected pulp. The molecular analysis of
pathogens, have identified several newer species.
Pulpal tissue may remain inflamed for a long period
of time; may and may not undergo necrosis. The factors
which stimulate pulp necrosis are:
• Virulence of bacteria
• Marked increase in intrapulpal pressure
• Host resistance
• Blood circulation
• Lymph drainage. blood vessels at the apical foramen. This in turn causes
the local tissue hypoxia, eventually leading to pulp
Once the pulp is exposed either by caries or trauma,
necrosis.
it is considered infected because micro-organisms gain
access immediately. The invading bacteria, however, Flowchart 5.1 depicts pulp reactions to various
may be confined entirely to the small area of pulp irritants.
exposure; the body and apical portion of the pulp may The diagnostic criteria for the assessment of pulp and
remain normal. The initial reaction of the pulp to periapical conditions are tabulated in Table 5.1.
bacterial invasion is an inflammatory response.
Polymorphonuclear cells reach the areas of initial insult, CLASSIFICATION OF PULP DISEASES
which prevent further dissemination of bacteria deeper There is no definite and accepted classification for
into the pulp. pulpal diseases. Usual classifications are based on
The pulpal reaction to an inflammation differs from (a) duration and severity of inflammation (acute,
other parts of the body as pulp is enclosed in a rigid subacute, chronic), (b) Presence/absence of symptoms
chamber. The inflammatory exudate facilitates rise in (symptomatic, asymptomatic) and (c) ability to heal
intrapulpal pressure, which strangulates the pulpal (reversible, irreversible).

Table 5.1 Diagnostic criteria for the assessment of pulp and periapical conditions
Stage Procedure Outcome
History Medical/Dental history
Description of present complain Provisional diagnosis
Previous treatment, if any
Clinical examination Extra-oral/intra-oral signs
Individual tooth assessment Identify and differentiate possible cause(s)
Clinical tests Pulp sensitivity tests Provisional diagnosis of the status of the
Palpation/percussion, etc. pulp and periapical tissues
Radiographic examination Periapical radiograph(s) Analysis of configuration of pulp
Provisional diagnosis of the periapical
status

5 Correlation of all above findings Combine the history, clinical examination,

clinical tests and radiographic examination
results
Definitive diagnosis

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 Diseases of the Dental Pulp 53

‘Acute inflammation’ implies inflammatory reactions B. Necrosis

which are closer to the source of the injury or infection; C. Pulp degeneration
peripheral chronic activity may and may not be evident. a. Denticles
As the intrapulpal or intraperiapical pressure increase b. Pulpal calcification
beyond the threshold limits of the sensory receptors, c. Pulp stones
varying degree of pain is felt. The absence of pain does D. Formation of secondary/irregular dentin in pulp
not mean that acute inflammatory response is absent. 3. Grossman’s classification
It means that the intrapulpal pressure is below the
A. Hyperaemia
threshold limits of the pain receptors.
B. Pulpitis
The predominant cells in the acute response are
a. Reversible pulpitis
polymorphonuclear leukocytes, neutrophils and tissue
i. Symptomatic (acute)
macrophages.
ii. Asymptomatic (chronic)
‘Subacute inflammation’ is a stage of hyperactivity
b. Irreversible pulpitis
between exudative (acute) and proliferative (chronic)
i. Acute
inflammatory components as in pulpitis and advanced
• Abnormal response to cold
form of apical periodontitis.
• Abnormal response to heat
This stage is characterized clinically by period of mild
ii. Chronic
to moderate symptoms.
• Hyperplastic pulpitis (pulp polyp)
‘Chronic inflammation’ is characterized by the
• Internal resorption
formation of granulation tissue in the area peripheral
to the exudative zone. This response may arise at the C. Pulp degeneration
end of acute inflammatory process or may develop from a. Calcific degeneration
the onset, when a low-grade irritation to the pulp or b. Atrophic degeneration
periapex is neutralized by effective tissue resistance. c. Fibrous degeneration
The intrapulpal pressure is below the threshold limits D. Pulp necrosis
of the pain receptors in chronic inflammation a. Coagulative necrosis
(asymptomatic or painless). When the strength of the b. Liquefactive necrosis
irritant is reduced, the granulomatous tissue c. Caseation necrosis
(granulation tissue plus chronic inflammatory cells) 4. Stock’s classification
becomes hyperactive, leading to repair and healing. A. Normal pulp
The predominant cells in chronic inflammation are B. Concussed pulp
lymphocytes, plasma cells and macrophages. C. Pulpitis
Pulpal diseases have been classified by various authors; a. Reversible
the accepted ones are described: b. Irreversible
1. Initially Gofung (1928) classified pulpal diseases as D. Pulp necrosis
A. Acute pulpitis E. Internal resorption
a. Partial 5. Walton’s and Torabinejad’s classification
b. General A. Pulpitis
c. Purulent a. Reversible
B. Chronic pulpitis b. Irreversible
a. Fibrous c. Hyperplastic
b. Hypertrophic
B. Pulp necrosis
c. Gangrenous
C. Pulp calcification
2. Classification by World Health Organization (WHO) D. Internal resorption
A. Pulpitis
a. Initial (hyperemia) 6. Abbot’s classification
b. Acute A. Clinically normal pulp (based on clinical
i. Suppurative (pulpal abscess) examination and test results)
c. Chronic B. Pulpitis
i. Ulcerative
ii. Hyperplastic (pulp polyp)
iii. Unspecified
a. Reversible pulpitis
i. Acute
ii. Chronic
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 54 Essentials of Endodontics

b. Irreversible pulpitis The pulp conditions following Grossman’s classifica-

i. Acute tion are described:
ii. Chronic 1. Hyperemia
C. Pulp necrosis Pulpal hyperemia implies excessive accumulation of the
a. Necrobiosis (part of pulp is necrotic and blood in the pulp with a predisposition to edema as a
inflamed; rest is irreversibly inflamed) result of prolonged vasodilation. An increased blood
b. No signs of infection volume in the confined environment of dental pulp
c. Infected increases the intrapulpal pressure especially in the
affected areas. Hyperemia is an initial and potentially
D. Pulpless, infected root canal system
reversible pulpal response that sets a stage for inflamma-
E. Degenerative changes tory cycle (Fig. 5.3). Hyperemia is not a disease entity
a. Atrophy but a symptom. There are two types of hyperemia:
b. Pulp canal calcification • Active hyperemia
i. Partial • Passive hyperemia
ii. Total In active hyperemia, there is an increased arterial
flow; whereas, in passive hyperemia, there is a
c. Hyperplasia
diminished venous flow. Clinically, both active and
d. Internal resorption passive hyperemia are indistinguishable.
i. Surface
Causative Factors
ii. Inflammatory
Various factors leading to hyperemia are:
iii. Replacement
• Trauma induced by dental procedures
F. Previous root canal treatment
• Excessive dehydration of cavity walls
a. No signs of infection • Irritation of exposed dentin from restorative materials
b. Infected • Injudicious use of mechanical separators/too rapid
c. Technical standard (based on radiographic orthodontic movements
appearance) • Trauma from high fillings
i. Adequate Management
ii. Inadequate Removal of the causative factor will lead to resolution
d. Other problems, e.g. perforations, fractured of hyperemia. The capability for resolution depends
instrument, missed canal, etc. upon strength and duration of irritant, extent of pulp
tissues affected and prior health status of the pulp itself.
SIGNS AND SYMPTOMS OF PULP CONDITIONS The prognosis for the pulp is favorable if the irritant
is removed early, otherwise the inflammatory process
Each condition of pulp is dynamic in nature; if not
sets in.
treated, progresses to another condition. Therefore, the
signs and symptoms overlap between various pulp
conditions. During diagnosis, the operator should keep
in mind the dynamic nature of pulp and also the
limitations of assessing the pulpal status. A ‘clinical’
normal healthy pulp implies that the pulp has no signs
and symptoms suggestive of any disease entity. The
term ‘clinical’ is used, since the pulp may exhibit some
histological changes. A clinically normal pulp does not
respond to heat stimuli; however it may react to cold
stimuli with mild pain, which can last for a minute or
so. Dentin sensitivity is also a separate entity, wherein,
no pulpal disease is noticed. The pain is consistent with

5 thermal, chemical, tactile or osmotic stimuli when

applied on dentin. The discomfort usually lingers till
the stimulus is removed. Fig. 5.3 Pulpal hyperaemia

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 Diseases of the Dental Pulp 55

2. Pulpitis
The pulp response in the form of inflammatory process
which is a defensive mechanism of the pulp is termed
as pulpitis. The inflammatory process in the pulp is
more prevalent in younger teeth with larger dentinal
tubules as compared to mature teeth with few and
occluded dentinal tubules. Pulpitis can be either
reversible or irreversible.
a. Reversible Pulpitis
It is a mild to moderate inflammation of the pulp which
is capable of returning to the normal state once the
stimuli is removed. Pain of brief duration may be
produced by stimuli, such as sweet and cold, rarely
heat; but the pain subsides as soon as the stimulus is
removed.
Fig. 5.4a Normal periapical areas
Etiology
The features causing reversible pulpitis are: Histopathology
• Accidental trauma/traumatic occlusion A mild to moderate inflammatory changes, limited to
• Quick thermal changes the area of involved dentinal tubules is seen histo-
• Excessive dehydration leading to desiccation of the pathologically. Reparative dentin, disruption of the
dentin odontoblast layer, dilated blood vessels, extravasation
• Oral galvanism of edema fluid and presence of immunocompetent
• Chemical insults chronic inflammatory cells are evident (Fig. 5.4b and c).

Clinical symptoms and diagnosis Treatment

‘Symptomatic reversible pulpitis’ is characterized by sharp The removal of irritants is the treatment preferred in
pain, last for a moment and generally disappears when reversible pulpitis. Insulating the exposed dentin results
the stimulus is removed. It is usually brought on by in diminished symptoms (if present) leading to reversal
cold, sweet/sour than hot food beverages. It does not of the inflammatory process in the pulpal tissue.
occur spontaneously and does not continue when the However, if irritation of pulp continues or increases in
cause has been removed. intensity, moderate to severe inflammation develops;
‘Asymptomatic reversible pulpitis’ may result from subsequently leading to irreversible pulpitis and
incipient caries and is resolved after removal of the eventually pulpal necrosis.
caries and restoration of the tooth.
Since the pulp is sensitive to temperature changes,
particularly cold; application of cold is an excellent
method of localizing and diagnosing the involved tooth.
A tooth with reversible pulpitis reacts normally to
percussion, palpation, and mobility test and the
periradicular tissues appear normal on radiographic
examination (Fig. 5.4a). The pulp may recover
completely, or the pain may last longer each time, and
intervals of relief may become shorter, until the pulp
finally succumbs.
The clinical difference between the reversible and
irreversible pulpitides is quantitative; the pain of
irreversible pulpitis is more severe and last longer. In
reversible pulpitis, the cause of the pain is generally
traceable to a stimulus, such as cold water; whereas in
irreversible pulpitis, the pain sets in without any
apparent stimulus.
Fig. 5.4b Acute pulpitis: Showing diffuse inflammation of
pulp
5

t.me/Dr_Mouayyad_AlbtousH
 56 Essentials of Endodontics

Fig. 5.4c Acute pulpitis: Core is composed of purulent

exudate consisting of polymorphonuclear leukocytes
against a background of fibrin, necrotic tissue debris, Fig 5.5a Widening of periodontal ligament along with
vascular dilatations and extravasated red blood cells initiation of rarefaction in the periapical area

The prognosis is usually favorable. The status of Clinical symptoms and diagnosis
the pulp is to be reviewed periodically (at least up to • In the early stages of irreversible pulpitis, pain may
3–6 months) to analyze clinical normal status of pulp. be caused by sudden temperature changes
If pulp is free of symptoms and respond normally to (particularly cold), sweet/acidic food. The pressure
pulp tests, it is to be designated as ‘normal’ (assuming of packing food into a cavity or even suction exerted
the inflammation has subsided).
by the tongue may also elicit pain.
b. Irreversible Pulpitis • The pain is continued and may linger for a longer
It is a persistent inflammatory condition of the pulp. period even after removal of the cause. Initially the
Irreversible pulpitis, if untreated, is categorized as pain is described as sharp, piercing and shooting. It
symptomatic (acute) or asymptomatic (chronic). The may be intermittent or continuous, depending on the
acutely inflamed pulp is symptomatic and the intensity of pulpal involvement. The change of
chronically inflamed pulp is asymptomatic. Acute posture (lying down or bending) exacerbates the pain
irreversible pulpitis exhibits spontaneous pain induced (changes in the intrapulpal pressure may be the
by hot/cold stimulus. The pain lingers on for several cause).
minutes, even after removal of the stimulus. Even mild • The pain can be referred to adjacent teeth, to the
temperature changes are sufficient to induce pain. temporal region when an upper posterior tooth is
Radiographs are usually not useful in diagnosis. The involved or to the postauricular/preauricular or
tooth can be tender on percussion, indicating spread
even to the lower border of the mandible, when a
of inflammation to periapical areas (pain on percussion
lower posterior tooth is involved.
may also indicate crack in the tooth). Chronic irrever-
sible pulpitis exhibits the same kind of symptoms; • The in-built pressure in the pulp, if continued, may
however, pain is less severe and intermittent than conti- lead to gnawing and/or throbbing pain (clinical
nuous as in acute case. Radiographically, periapical exposing the pulp provide immediate relief).
changes become evident at later stages (Fig. 5.5a). • Patients are often awake at night by the pain, which
Etiology continues to be intolerable. Pain is increased by heat
The irreversible pulpitis is usually a progression from and is sometimes relieved by cold. Apical perio-
reversible pulpitis. dontitis is absent except in the condition where the
The most common cause of the irreversible pulpitis pulpal inflammation has crossed the apical barrier
and involves the periradicular periodontium.
5 is the bacterial contamination; however, chemical,
thermal and/or mechanical factor may also cause
irreversible pulpitis.
The diagnostic features of pulp diseases are
summarized in Table 5.2.

t.me/Dr_Mouayyad_AlbtousH
 Diseases of the Dental Pulp 57

Pain in advanced Histopathology

responsive in late

Normal appea-
Irreversible pulpitis may be caused by a long standing

rance; may be

radiolucency
No response;
Pulp necrosis

No response noxious stimulus such as caries. As caries penetrates

stages only

periapical
deep into dentin, it causes a chronic inflammatory

stages
response in the underlying pulp. If the caries is not
removed, the inflammatory changes in the pulp may
increase in severity as the caries approaches the pulp.
Exaggerated response

The inflammatory reaction produces micro-abscess. The

to cold; pain lingers

ligament/thickening
Normal periodontal pulp, trying to protect itself, walls off the areas with
Spontaneous pain
Irreversible pulpitis

fibrous connective tissue. Microscopically, an area of the

May be positive
(symptomatic)

of periodontal abscess and a zone of necrotic tissue is evident (Fig. 5.5b).

ligament The micro-organisms present in the late carious stage
along with lymphocytes, plasma cells and tissue macro-
phages are also seen. No micro-organisms are present
in the center of the abscess because of the phagocytic
activity of the polymorphonuclear cells. If the carious
response; discomfort

ligament/ thickening
Normal periodontal

process continues to advance and penetrates the pulp,

Irreversible pulpitis

No history of pain

Quick and sharp

the histological picture changes. It has been established

(asymptomatic)

may not linger

of periodontal

that bacteria needed to be within 1.0 mm of the pulp

before inflammatory changes could be observed. Evidence
Negative

ligament

of irreversible pathosis may not be observed until the

reparative dentin is invaded. An area of ulceration
(chronic ulcerative pulpitis) is evident that drains
through the carious exposure into the oral cavity and
response; discomfort

reduces the intrapulpal pressure, and therefore, the

spontaneous pain
Reversible pulpitis

Quick and sharp

pain. An area of necrotic tissue and zone of proliferating

(symptomatic)

may not linger

fibroblasts forming the walls of the lesion is also seen.

No history of

Negative

Differential diagnosis: reversible/ irreversible pulpitis

Normal

In reversible pulpitis, the pain is transitory, lasting just

for a moment; whereas, in irreversible pulpitis, the pain
may last longer. Thermal tests are useful in locating
Mild response to cold

Normal; presence of

the affected tooth. The electric pulp test requires less

No history of pain
Reversible pulpitis

current to elicit a response than on a normal tooth.

(asymptomatic)

negative

caries
Table 5.2 Diagnostic features of pulpal diseases

No history of pain

Mild response to
cold; does not
Normal pulp

Negative

Normal
linger

Radiographic findings
Pain on percussion
Thermal (cold) test
Clinical features

Fig 5.5b Chronic pulpitis: Presence of loose, delicate

connective tissue with bundles of dense collagen and
5
History

diffuse infiltration of chronic inflammatory cells with

dystrophic calcification

t.me/Dr_Mouayyad_AlbtousH
 58 Essentials of Endodontics

Reversible pulpitis Irreversible pulpitis

• Pain traceable to stimulus • May not be traceable to
(cold water/air) stimulus (may be without
any apparent stimulus)
• Pain is transitory (last for • Pain lasts longer and severe
a moment)
• Symptoms subside • Pain usually lingers
immediately after
removal of cause
• Less current required to • Less current required to
elicit pain elicit pain initially; more
current in advanced cases
• Infrequent episodes of • Pain is increasing in fre-
pain/discomfort quency, to be continuous

Treatment
Root canal treatment is the treatment of choice. The Fig. 5.6 Pulp polyp
prognosis is favorable.
Pathophysiology
c. Chronic Hyperplastic Pulpitis (Pulp Polyp) The pulp polyp is the result of both mechanical
Chronic hyperplastic pulpitis or proliferative pulpitis irritation and bacterial invasion into the pulp chamber,
is generally recognized as pulp polyp. This is a specific mainly due to caries or trauma. The large exposure of
type of inflammatory hyperplasia, which occur in pulpal tissue to the oral environment followed by
young pulp (with abundant blood supply) due to bacterial invasion results in a chronic inflammatory
extensive carious exposure. This disorder is charac- response that stimulates an exuberant granulation
terized by overgrowth of granulation tissue, resulting tissue reaction. The chronically inflamed granulation
from long standing, low grade irritation. tissue proliferate from the pulp cavity and is covered
The hyperplastic pulpitis occurs almost exclusively by stratified squamous epithelium (Fig. 5.7).
in children and young adults, and both in primary and The hyperplastic tissue reaction occurs because the
permanent dentition. young dental pulp has a rich blood supply and
The clinical appearance of the polypoid tissue shows favorable immune response that is more resistant to
fleshy, reddish pulpal mass, filling most of the pulp bacterial infection. Furthermore, because the tooth is
chamber or even sometimes extends beyond the
open to the oral cavity, transudates and exudates from
confines of the tooth. Polypoid tissue is less sensitive
the inflamed pulpal tissue drain freely and do not
than normal pulp tissue and more sensitive than
accumulate within the restricted and rigid confines of
gingival tissue. Cutting of this tissue produces no pain,
but the pressure transmitted to the pulp may cause mild
pain. The tissue bleeds easily because of a rich network
of blood vessels.
The pulp polyp exhibits the following features:
• A spongy, soft tissue nodule extrudes from the
cavitated or fractured surface of a tooth (Fig. 5.6).
• The surface texture (color) varies from smooth (pink)
to granular (red and white).
• Polyps usually fill the entire pulpal chamber of the
tooth.
• Polyps usually develop in carious primary molars
and first permanent molars because, anatomically in
young persons, these teeth have large pulp chambers.
Less frequently, maxillary central incisors in both
dentitions are affected.
• A pulp polyp is a single lesion, but multiple teeth

5 may be affected.
• Teeth with open or incomplete apexification of the
root apices are the most susceptible.
Fig. 5.7 Chronic hyperplastic pulpitis: Chronically inflamed
granulation tissue proliferating from the pulp cavity and
covered by stratified squamous epithelium

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 Diseases of the Dental Pulp 59

the tooth. Tissue necrosis with destruction of the External root resorption is usually caused by the
microcirculation that usually accompanies irreversible transmission of bacterial toxins from infected pulp via
pulpitis may not occur because of lack of significant dentinal tubules to an external root surface that might
intrapulpal pressure. In young teeth with open apices, have been partly denuded of the cementum. Classic
the risk of pulpal necrosis is minimum. The presence cells are stimulated to the region by inflammatory
of a rich vascular network in the young pulpal tissue is mediators such as prostaglandins and cytokines, which
an important protective mechanism against the are liberated as part of the inflammatory process. The
inflammatory response that significantly decreases with breakdown of dentin further stimulates pulpal
age. inflammation (details in Chapter 27).
Etiology 3. Pulp Degeneration
A large open cavity, a young resistant pulp and a
The degeneration of the pulp is seldom recognized
chronic low grade stimulus are the causative agents for
clinically, especially at early stages. The degeneration
hyperplastic pulpitis. Mechanical irritation and bacterial
generally affects older people, though teeth of younger
invasion often provide the stimulus.
people, as a result of persistent and mild irritation, may
Symptoms also get affected.
• Pulp polyps reach a maximum size within a couple It may be induced by the attrition of teeth, erosion
of months and then remain static. and bacterial invasion, etc. Once the pulp gets
• Pulp polyps are usually asymptomatic; direct degenerated, the tooth becomes discolored and does
pressure during mastication may cause mild-to- not respond to pulp sensitivity tests; however, teeth
moderate tenderness. with partial degeneration respond to external stimuli.
• Localized bleeding may occur, especially when the The pulpal degeneration is categorized as:
tissue is traumatized. a. Calcific degeneration
• Mobility of the tooth and sensitivity to percussion b. Atrophic degeneration
are usually absent. c. Fibrous degeneration
Treatment a. Calcific Degeneration
The root canal treatment is preferred in pulp polyp;
Calcific degeneration (in the form of pulp stones or
however, formocresol pulpotomy has also been tried,
diffuse calcification) usually occur in response to
especially in primary teeth. The removal of hyperplastic
trauma, caries, periodontal disease, or other irritants
pulpal mass with a sharp spoon excavator, followed
(Fig. 5.8a to d). The calcification is generally initiated
by control of bleeding, formocresol dressing and filling
in the pulp chamber; may involve root canal partially
can be carried out in young teeth. The prognosis is
or complete. Complete calcification is referred to as
favorable.
‘canal obliteration’.
d. Internal/External Resorption
Trauma in the form of an accident or during cavity
preparation, are considered as triggering mechanism
for internal resorption. Internal resorption, if continued,
may lead to pulp necrosis. Internal resorption is
categorized in three forms, viz. surface, inflammatory
and replacement resorption. Surface resorption usually
remains undiagnosed and needs no treatment.
Inflammatory resorption is common; occurs because of
activation of odontoclasts within the inflamed pulp
tissue. Radiographically, an oval-shaped area is seen
along the canal walls. Apical periodontitis develops
once the canal becomes infected. Replacement
resorption is usually uncommon; dentin is resorbed and
replaced by bone like tissue. This condition is usually
asymptomatic; however, radiographically irregular
enlargement of pulp space filled with bone-like tissues
is evident.
Fig. 5.8a Complete calcification of the pulp chamber and
palatal root canal of maxillary first molar (may be due to
caries)
5

t.me/Dr_Mouayyad_AlbtousH
 60 Essentials of Endodontics

Calcific degeneration does not represent the

pathology of the pulp rather may occur with ageing or
low grade irritation. The condition is recognized
radiographically. Discrete areas of localized pulp
necrosis resulting from small infarctions may be caused
by deep scaling that interrupts the blood supply to a
lateral canal, often lead to localized calcification as a
defense reaction. The teeth are usually asymptomatic
but may exhibit less sparkling appearance or looks more
opaque and discolored.

Pulp canal obliteration: Key features

• Traumatized anterior teeth usually develop pulp canal
obliteration
• Mostly teeth are symptom-free
Fig. 5.8b Complete calcification of the pulp chamber and • Pulp vitality tests are unreliable
root canal of maxillary incisor (calcific degeneration of
• Discoloration is common clinical finding
pulp: Canal obliteration)
• Require no treatment in routine; if need of treatment,
calcification pose challenge

b. Atrophic Degeneration
Pulpal atrophy normally occurs with the advancing age.
With age, the number and size of cells decreases and
collagen fiber increases. The aged pulp seems less likely
to resist various insults than the young, healthy and
normal pulp. No significant clinical/radiographic signs
are present. The size of pulp chamber is reduced and
pulp may exhibit delayed response to pulp testing. No
treatment is indicated.

c. Fibrous Degeneration
In this condition, the cellular content of the pulp is
replaced by the fibrous connective tissue, which on
Fig. 5.8c Pulp stone in a coronal chamber under operating removal from pulp gives a leathery fibrous appearance.
microscope
4. Pulp Necrosis
Pulp necrosis can be partial or total, depending on
whether part or entire pulp is involved. The term
‘Necrobiosis’ is preferred in case of partial necrosis. It
implies presence of bacteria within the necrotic part of
the pulp, which may be invading the rest of the pulp
tissue. Pulp sensitivity tests are usually inconclusive at
this stage. The symptoms are mild/intermittent pain
lingering for the last over many weeks. Radio-
graphically signs of apical periodontitis are evident
(usual widening of periodontal ligament). Once the
pulp is invaded by bacteria, then the bacteria usually
spread along the pulp tissue. Micro-organisms grow
using pulp tissue as nutrient and slowly render the

5 Fig. 5.8d Pulp stones in an aged dental pulp

tooth pulpless. Necrosis is usually a sequel to
inflammation (untreated caries, leaking restorations,
failed pulp capping); may occur following traumatic

t.me/Dr_Mouayyad_AlbtousH
 Diseases of the Dental Pulp 61

injuries in which the pulp is destroyed before an Types of Pulp Necrosis

inflammatory reaction takes place. Trauma leads to a. Coagulative
severing of apical blood supply if the tooth is displaced
b. Liquefactive
(luxation/avulsion) or significant damage to apical
periodontal ligament (subluxation). The ischemic c. Caseation
infarction, which develops may lead to dry gangrenous a. Coagulative necrosis: It is a type of necrosis caused
necrotic pulp (Fig. 5.9a and b). Radiographic changes by irreversible focal injury of pulp, most commonly
are not significant unless there is apical involvement. due to ischemic cessation of blood flow. Soluble portion
Pain is also not present unless periodontal ligament is
of pulp tissue is precipitated or converted into a solid
affected. Long standing necrosis leads to dull,
mass.
continuous pain which increases with heat and
temporarily subsides by cold. This might be due to the b. Liquefactive necrosis: This type of necrosis of pulp
gases generated by bacteria in necrosed teeth, expands occurs following ischemic injury and bacterial infection.
by heating causing pain and contract with cold which Affected pulp becomes soft and liquefied in the centre
help to minimize the pain temporarily. containing necrotic debris.

c. Caseation necrosis: It is a form of necrosis wherein

combined features of both coagulation and liquefaction
necrosis is seen. The pulp tissue is soft, granular and
converted into a cheesy mass consisting of coagulated
proteins.
The summary of pulp condition and treatment
strategies is tabulated in Table 5.3.

Table 5.3 Pulp condition and treatment strategies

Condition of the pulp Treatment strategies
Dentin hypersensitivity • Occlusion of exposed dentinal
tubules with desensitizing agents.
Reversible pulpitis • Removal of the cause
(acute and chronic) • Follow-up to assess healing
Fig. 5.9a Chronic periapical abscess in relation to maxillary • If not healed, root canal treatment
right incisor with sinus formation (clinical) Irreversible pulpitis • Routine endodontic treatment
(acute and chronic)
Chronic hyperplastic • Conventional root canal treatment
pulpitis if apices are mature
• Formocresol pulpotomy in young
teeth
Pulp atrophy • No treatment required, if physio-
logical
• If pathological, remove the cause
Pulp calcification • No treatment required unless the
(partial and total) canal is infected
• If infected, conventional endodontic
treatment
Root resorption • Conventional endodontic treat-
(external/internal) ment with regenerative medica-
ments in the canal
Pulp necrosis • Conventional endodontic treat-

Fig. 5.9b Chronic periapical abscess in relation to maxillary

right incisor (radiological)
ment
• Surgical intervention, if necessary 5

t.me/Dr_Mouayyad_AlbtousH
 62 Essentials of Endodontics

The end products of pulp decomposition are those 9. Goga R, Chandler P and Oginni AO. Pulp stones: a review.
of protein decomposition, namely hydrogen sulfide, Int. Endod. J.: 2008; 41:457–468.
ammonia, fatty substances, water and carbon dioxide. 10. Jansson L, Ehnevid H, Lindskog S and Blomlof L. Development
The intermediate products such as indole, skatole, of periapical lesions. Swed. Dent. J.: 1993; 17:85–93.
putrescine and cadaverine, contribute to the unpleasant 11. Johnson RH, Dachi SF and Haley JV. Pulpal hyperaemia: a
odor sometimes emanating from the root canal. correlation of clinical and histologic data from 706 teeth. J.
Am. Dent. Assoc.: 1970; 81:108–117.
12. Levin LG, Law AS, Holland GR, Abbott PV and Roda RS.
BIBLIOGRAPHY Identify and define all diagnostic terms for pulpal health and
1. Abott PV and Yu C. A clinical classification of the status of disease states. J. Endod.: 2009; 35:1645–1657.
the pulp and the root canal system. Aust. Dent. J. Endod.: 13. Nair PN. Apical periodontitis: a dynamic encounter between
2007; 52:S17–S31. root canal infection and host response. Periodontol 2000:
1997; 13:121–148.
2. Abott PV. Assessing restored teeth with pulp and periapical
diseases for the presence of cracks, caries and marginal break- 14. Oginni AO, Sofowora CAA and Kolawole KA. Evaluation of
down. Aust. Dent. J.: 2004; 49:33–39. radiographs, clinical signs and symptoms associated with pulp
canal obliteration: an aid to treatment decision. Dent.
3. Abott PV. Classification, diagnosis and clinical manifestation
Traumatology.: 2009; 25:620–625.
of apical periodontitis. Endod. Topics: 2004; 8:36–54.
15. Paterson RC and Pountney SK. Pulp response to Streptococcus
4. Abott PV. The periapical space – dynamic interface. Ann. R mutans. Oral Surg., Oral Med., Oral Pathol.: 1987; 64:339–347.
Australas Coll. Dent. Surg.: 2000; 15:223–234.
16. Smith JW. Calcific metamorphosis: a treatment dilemma. Oral
5. Ali SG and Mulay S. Pulpitis: A review. IOSR J. Dent. and Surg., Oral Med., Oral Pathol.: 1982; 54:441–444.
Med. Sci.: 2015; 14:92–97.
17. Vibhute NA, Vibhute AH, Daule RT, Bsal PP and Aditi M.
6. Bender IB. Reversible and irreversible painful pulpitides: Hard facts about stones: pulpal calcifications: A review. J.
diagnosis and treatment. Aust. Endod. J.: 2000; 26:10–14. Pat. Care: 2016; 2:1–4.
7. Dummer PM, Hicks R and Huws D. Clinical signs and 18. Yu C and Abbott PV. An overview of the dental pulp: its functions
symptoms in pulp disease. Int. Endod. J.: 1980; 13:27–35. and responses to injury. Aust. Dent. J.: 2007; 52:84–116.
8. Dummer PM, Hicks R and Huws D. Clinical signs and 19. Zero DT, Zandona AF, Vail, MM and Spolnik KJ. Dental caries
symptoms in pulp disease. Int. Endod. J.: 1980; 13:27–35. and pulpal disease. Dent. Clin. North Am.: 2011; 29–46.

t.me/Dr_Mouayyad_AlbtousH
Chapter
6
Diseases of
Periradicular Tissues

The periradicular tissues have an unlimited source of or non-endodontic origin.’ The periradicular lesions
undifferentiated cells that participate in inflammation generally are of inflammatory origin; however, a few
and repair as well. These tissues do have rich collateral periradicular lesions may not be due to inflamed/
blood supply and lymphatic drainage. The rich blood necrotic pulps.
supply usually counter act the destructive activities of
the irritants from within and outside the root canal. GENERAL FEATURES
Depending on severity of irritation, duration and host The micro-organisms that cause dental caries do not
response, periradicular pathosis may range from mild confine to enamel only. The microbes invade dentin and
inflammation to extensive damage of periodontal the pulp as they progress and multiply. If caries is
attachment tissues. The injury leads to cellular damage, not treated during the initial stages, bacteria gain access
releasing specific and non-specific immunologic to the pulp through the dentinal tubules. As they
mediators of the inflammatory process. enter the pulp, an inflammatory reaction is produced,
Periradicular inflammation gets initiated during which leads to pulpal diseases and subsequently, pulp
pulpal inflammation and even before the pulp is necrosis. From the pulp, bacteria can enter the
completely necrotic. Micro-organisms, their degrada- surrounding bone through the apical foramen. The
tion products, mediators of inflammation and ensuing response of the tissues surrounding the apical
damaging pulpal tissues stimulate the inflammatory
foramina may result in periradicular diseases.
reaction in the periradicular tissues. That is why, many
a times, the pulp may remain partially vital, along with The periradicular diseases are mainly caused by
periradicular pathosis. bacteria prevalent in necrosed pulp. The necrosis of
The structures surrounding the apex of tooth roots pulp is generally the sequelae of bacterial invasion of
where the apical foramina are located, are known as pulp or in few cases the cracked teeth. The traumatic
the ‘periradicular tissues’ (peri = around, radicular = injuries, may be in later stages, also lead to pulp
root). The tissues around apical foramen/root apex are necrosis.
composed of cementum, periodontal ligament and the Since periradicular inflammation involves the
alveolar bone. The micro-organisms from infected pulp periodontal ligament and the alveolar process (two
tissues may invade these periapical tissues via apical important components of the periodontium), the term
foramen and/or lateral/accessory canals trespassing ‘periodontitis’ is used. More so, if the inflammation is
the root cementum. The lesions produced by periapical confined to the apical region, the term ‘apical
infection are generally in close proximity to the apices periodontitis’ is used, which can be acute or chronic.
of the teeth. Periapical lesions are mainly recognized The periradicular diseases can be of endodontic
during radiographic examination. Clinically, these (pulp) origin or non-endodontic origin. Pulp inflamma-
lesions can be diagnosed by patient’s symptoms; tion may invade the periapical tissues leading to
however, visual-intraoral examination may not be periradicular diseases; periapical tissues may get
adequate to identify these lesions. involved due to periodontal diseases, trauma and/or
remnants of odontogenic epithelium causing peri-
DEFINITION radicular cysts, etc. A few iatrogenic causes (chemical
Periradicular diseases are defined as ‘the diseases irrigants/medicaments, over-instrumentation of root
occurring around the apex of a tooth, may be of endodontic canals) also lead to periradicular diseases.

63

t.me/Dr_Mouayyad_AlbtousH
 64 Essentials of Endodontics

Grossman’s classification
Periradicular diseases: possible causes
1. Acute apical periodontitis
Bacterial
2. Acute alveolar abscess
• Infection from pulp
3. Chronic alveolar abscess
• Infection from periodontium
4. Subacute alveolar abscess
Traumatic 5. Granuloma
• Physical trauma (blow) 6. Cyst
• Traumatic occlusion
Later, the classification was modified as follows:
• Aggressive thermal stimulus
1. Acute periradicular disease
Chemical/Iatrogenic a. Acute apical periodontitis (vital and non-vital)
• Irrigants and intracanal medicaments b. Acute alveolar abscess
• Over-instrumentation/overfilling of root canals c. Phoenix abscess
2. Chronic periradicular diseases
CLASSIFICATION a. Chronic apical periodontitis
The earlier investigators classified periradicular • Chronic alveolar abscess
diseases as: • Cystic apical periodontitis/radicular cysts
i. Nonseptic pericementitis b. Persistent apical periodontitis
ii. Septic pericementitis 3. Condensing osteitis
iii. Pericemental abscess (inflammation of periapical 4. External root resorption
tissues without infection) 5. Diseases of non-endodontic origin
iv. Alveolar abscess (infection with or without sinus)
The term ‘pericementitis’ was later changed to WHO (World Health Organization) classification
‘periodontitis’. Three main categories of periodontitis WHO specified periradicular disease by coding; the
were recognized, viz. traumatic, chemical/iatrogenic codes are:
and bacterial. The diseases of periapical tissues have Code 4.4: Acute apical periodontitis (apical periodontitis
been identified on this categorization. of pulp origin)
Over the years the diseases of periapical tissues have
Code 4.5: Chronic apical periodontitis (granuloma)
been defined and classified by different authors.
Code 4.6: Periapical abscess with sinus to maxillary
The commonly referred classifications are: antrum
Prinz’s classification • Sinus with nasal cavity
1. Acute pericementitis
• Sinus with oral cavity
i. Acute apical pericementitis
• Sinus with skin
ii. Acute marginal pericementitis
iii. Acute diffuse suppurative pericementitis Code 4.7: Periapical abscess without sinus (dento-
iv. Acute intraradicular pericementitis alveolar abscess and periodontal abscess)
2. Chronic pericementitis Code 4.8: Radicular cyst (apical periodontal cyst,
i. Chronic apical suppurative pericementitis periapical cyst)
ii. Chronic proliferative pericementitis • Apical and lateral cyst
• Residual cyst
Coolidge’s classification • Inflammatory paradental cyst
1. Acute inflammation
i. Traumatic and chemical periodontitis Code 4.9: Unspecified diseases of pulp and periapical
tissues
ii. Apical periodontitis from infection
iii. Acute alveolar abscess WHO further subdivided the diseases of periapical tissues
2. Chronic inflammation into four categories:
i. Suppurative periodontitis i. Distribution of inflammatory cells in the lesion
ii. Proliferative periodontitis ii. Whether epithelial cells are present or absent

6
3. Granuloma iii. Whether the lesion is transformed to cyst
4. Radicular cyst iv. Relationship of cyst cavity to root canal of the
5. Condensing osteitis affected tooth

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 Diseases of Periradicular Tissues 65

Ingle’s classification 2. Non-painful periradicular diseases

Ingle’s classified periradicular diseases as painful and a. Condensing osteitis
non-painful. b. Chronic apical periodontitis
1. Painful periradicular diseases i. Incipient stage
a. Acute apical periodontitis ii. Advanced stage
b. Advanced apical periodontitis • Periapical granuloma
i. Acute apical abscess • Suppurative apical periodontitis
ii. Phoenix abscess • Apical cyst
iii. Chronic apical abscess (suppurative apical The definitions of commonly used terms associated
periodontitis) with periradicular diseases are briefed in Table 6.1.

Table 6.1 Periradicular lesions; definitions of commonly used terms

Terms Definition
Normal periapical tissues The lamina dura surrounding the tooth is intact along with uniform periodontal ligament
space (teeth will not be abnormally sensitive to percussion or palpation)
Acute periapical periodontitis Inflammation of the apical periodontium producing clinical symptoms, viz. painful
response to biting and percussion
Sub-acute periapical periodontitis Inflammation of the apical periodontium producing mild clinical symptoms as
compared to acute periapical periodontitis
Cellulitis Acute and edematous spread of an acute inflammatory process; abscess, which
cannot establish drainage, may spread diffusely through fascial planes of soft tissues
Parulis A mass of subacutely inflamed granulation tissue at the intraoral opening of a sinus tract
Abscess Localized collection of purulent exudate (pus) in a cavity formed by the disintegration
of tissues
Pus A product of inflammation consisting of leucocyte, degenerated tissue elements, tissue
fluids and micro-organisms
Sinus A hollow space in a bone or other tissues; literally, a hollow cavity in skull connecting
with nasal cavity
Sinus tract A tract leading to a suppurating cavity
Chronic periapical periodontitis Inflammation and destruction of apical periodontium that is of pulpal origin which
does not produce clinical symptoms (a periradicular radiolucent area may be present)
Acute periapical abscess/ An inflammatory reaction to pulpal infection characterized by rapid onset, spontaneous
Acute apical abscess/ pain, tenderness, pus formation and eventual swelling of the associated tissues
Acute periradicular abscess/
Acute alveolar abscess/
Dentoalveolar abscess
Chronic periradicular abscess/ An inflammatory reaction to pulpal infection and necrosis characterized by gradual
Suppurative periradicular periodontitis/ onset, little/no discomfort and the intermittent discharge of pus through an associated
Chronic periapical abscess/ sinus tract
Chronic alveolar abscess/
Chronic dentoalveolar abscess
Periapical scar The defect created by periapical inflammatory lesion may be filled with dense
collagenous tissues rather than normal bony tissue (usually occurs when both facial
and lingual cortical plates have been lost)
Condensing osteitis/ A diffuse radiopaque lesion, representing a localized bony reaction to a low grade
Sclerosing osteitis/ inflammatory stimulus, usually seen at the apex of a tooth (or its extraction site, where
Periradicular osteosclerosis/ there might be a long standing pulp pathosis)
Focal sclerosing osteomyelitis/
Sclerotic bone
Sequestrum A fragment of necrotic bone that has been separated from the adjacent vital bone 6

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 66 Essentials of Endodontics

A. PERIRADICULAR DISEASES OF ENDODONTIC ORIGIN • Forcing of irritating medicaments like formocresol

The periradicular lesions of endodontic origin are in the periradicular tissues.
mainly categorized as: • Extension of root canal filling material into the
1. Acute periradicular lesions periradicular tissues, which acts as a continuous
source of irritation.
2. Chronic periradicular lesions
Periradicular lesions of shorter duration associated Diagnosis
with symptoms such as pain are known as acute or Patient may inform as regard recently placed occlusal
symptomatic; whereas, those of longer duration with restoration. Application of pressure by finger tip or
mild or no symptoms are termed as chronic or asympto- lightly tapping the tooth with the butt end of the mouth
matic. mirror results in excruciating pain.
Acute apical periodontitis, as a sequel of pulp
1. Acute Periradicular Lesions necrosis, may not respond to pulp vitality tests;
The initial response of inflammation in periradicular whereas, acute apical periodontitis caused by an
tissues is pain. The polymorphonuclear cells and the abnormal occlusal contact responds normally to the
edematous fluid fill the space between the tooth and pulp vitality tests.
the bone, thereby increasing the pressure, which Differential diagnosis
compresses the nerve endings resulting in severe pain. A differential diagnosis should be made between the
The pain continues until bone is resorbed creating some acute apical periodontitis and acute apical abscess. The
space, which accommodates the fluid and releases the patient’s history, signs—symptoms and clinical
pressure. examination can differentiate between these two
Acute periradicular lesions are the following types: periradicular entities.
a. Acute apical periodontitis
Signs and symptoms
b. Acute apical/alveolar abscess
• Severe pain (throbbing/constant)
c. Acute exacerbation of chronic lesion (phoenix • Tender on percussion (pain on biting)
abscess)
• Tooth may be slightly elevated from its socket
because of pressure of fluid collected in the peri-
a. Acute Apical Periodontitis
radicular tissues
Acute apical periodontitis is the inflammation of the • Delayed vitality tests
periodontium as a result of trauma, bacterial infection
• No swelling
initiating from within the root canal space, regardless
of the pulp being vital or non-vital. The lesions are Radiographic features
painful, especially during biting and on percussion. The Lamina dura remains intact without any break in
continuity, especially in case of vital pulps. The
Causes of acute apical periodontitis in a vital pulp
periodontal ligament space may appear normal or
• Trauma caused by an abnormal or premature slightly enlarged (Fig. 6.1).
occlusal contact (seen in recently placed occlusal
restoration).
• Forceful wedging of an object between the teeth; for
example, tooth pick, wedge, use of separators during
restorative and orthodontic procedures, rubber dam
application etc.
• Blow on to the tooth.
Causes of acute apical periodontitis in a non-vital pulp
• As a sequel of pulpal diseases; diffusion of potential
irritants from within the pulp spaces.
• Over instrumentation during root canal cleaning and
shaping procedure.

6 • Micro-organism and debris are pushed inadvertently

into the periradicular tissues during root canal
preparation.
Fig. 6.1 Acute apical periodontitis (slight widening of
periodontal ligament in mandibular first molar)

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 Diseases of Periradicular Tissues 67

Histological features • Spontaneous or throbbing pain

Inflammatory reaction leads to dilatation of blood • Tender on percussion
vessels. Polymorphonuclear cells initiate inflammatory
Diagnosis
response (polymorphonuclear cells and macrophages
are visible within a localized area at the apex). Serous The affected tooth does not respond to electric and
exudate accumulates; subsequently leading to thermal tests. Clinical examination can be effective in
distension of periodontal ligament spaces. A small area diagnosing acute abscess. The tooth may be tender on
of liquefaction necrosis may be evident. In case irritation percussion; apical mucosa is tender on palpation and
continues, it may lead to bone/root resorption. Initial the tooth may be mobile and extruded.
bone and/or root resorption are not evident radio- Radiographic features
graphically; however, may be identified histologically. The radiographic features range from thickening of
Treatment periodontal ligament space to a frank resorptive lesion.
It is important to understand whether acute apical Initial lesions do not show much changes (only widened
periodontitis is associated with a vital or non vital pulp. periodontal ligament); as hard tissues get involved,
Determining the cause and relieving the patient's acute definite radiolucency can be seen (Fig. 6.2).
symptoms accordingly is the line of treatment. Root Histological features
canal treatment can be initiated, if pulp is involved. Increase in pressure leads to hypoxia of pulp tissues;
Appropriate anti-inflammatory analgesics can also be subsequently formation of pus because of breakdown
prescribed. of polymorphonuclear cells and lysis of pulp remnants.
Prognosis is usually favorable. Histological features show a localized lesion of lique-
faction necrosis containing numerous polymorpho-
Acute apical periodontitis: Key features nuclear cells, debris, cell remnants and an accumulation
• Tooth may be vital or non-vital of purulent exudates.
• Throbbing/constant pain
The abscess is usually surrounded by granulomatous
• No swelling
tissues; therefore, the lesion is categorized as an abscess
• Pain on percussion (pain on biting)
within a granuloma. Significantly, the abscess may not
• Pulp vitality tests can be negative
• Lamina dura remains intact; periodontal ligament can be
communicate directly with the apical foramen.
slightly widened Treatment
• Removal of cause should be the priority; root canal treatment
Usually, acute abscess is an emergency since the patient
in case tooth is non-vital
is in great agony. The main objective of emergency
b. Acute Apical/Alveolar Abscess management is to relieve the periradicular pressure by
establishing the drainage. Most common approach is
Acute apical/alveolar abscess is a localized collection
of pus in the alveolar bone around the root apex; the
infection following necrosis of pulp extends through
the apical foramen into the periapical tissues. The
abscess is sequel of the apical periodontitis.
Etiology
• Bacterial invasion from the necrotic pulp
• Traumatic/chemical involvement of pulp
• Mechanical irritation may also lead to acute apical
abscess
Signs and symptoms
Depending upon severity of the reaction, patients with
acute apical abscess usually have signs/symptoms as:
• Moderate to severe discomfort/swelling
• Systemic manifestations of an infective process such

6
as high temperature, malaise and leukocytosis
• The tooth is often elevated in its socket and interferes Fig. 6.2 Acute apical abscess (widening of periodontal
in occlusion. ligament in mandibular second premolar)

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 68 Essentials of Endodontics

to open the tooth and allow purulent exudates to escape

through the root canals. After the drainage, the
conventional endodontic treatment can be carried out.
In case, where the drainage is not established through
the root canal, surgical incision and drainage can be
carried out through the periapical tissues. Antibiotics
and anti-inflammatory analgesics can be prescribed.
The tooth should be dis-occluded slightly, if it is
extruded from its socket.
Prognosis is usually favourable.

Acute alveolar/apical abscess: Key features

• Non-vital tooth (do not respond to vitality tests)
• Palpable swelling
• Spontaneous/throbbing pain
• Tender on percussion
• Systemic manifestation (fever, malaise, etc.) Fig. 6.3 Phoenix abscess (clinical presentation)
• Tooth extruded from socket (not mobile)
• Widening of periodontal ligament to frank radiolucency Diagnosis
• Drainage through root canal or periapical tissues is effective; Lack of response to vitality test is indicative of necrotic
followed by root canal treatment pulp. In rare cases, a tooth may respond to the electric
• Good prognosis pulp test because of fluid in the root canal; or in a multi-
rooted tooth. Only history and associated symptoms
c. Acute Exacerbation of Chronic Lesion (Phoenix
distinguish phoenix abscess from acute alveolar
Abscess)
abscess. The tooth is tender on percussion. Cellulitis of
Phoenix Abscess is a condition in which acute the area is evident.
suppurative inflammation is superimposed on an
existing chronic apical periodontitis (acute exacerbation Radiographic features
of a chronic lesion). Radiographs show radiolucent areas as prevalent in
The chronic lesions like periradicular granuloma or chronic periradicular lesions. A well-defined peri-
the cyst, suddenly present acute inflammatory radicular lesion is evident.
symptoms. The spontaneous metamorphosis from Treatment
dormant chronicity to a sudden, acute condition gives
Only anti-inflammatory drugs including steroids are
the analogy of ‘Phoenix’. Phoenix, a mythological bird,
helpful. Antiallergic drugs (antihistamines) are also
was destroyed in fire that arose again from the ashes
effective. Surgical incision etc. is not advised.
to start another life. Chronic apical periodontitis was
equated to the ashes and an acute apical abscess was
Phoenix abscess: Key features
the Phoenix coming to life. • Acute exacerbation of existing chronic lesion
A phoenix abscess may develop spontaneously and • Change in equilibrium of microbes; initiation of root canal
immediately after the initiation of endodontic treatment treatment of long-standing chronic case facilitates ingress of
on an asymptomatic tooth. As the root canals are opened, micro-organisms/debris, etc. into periapical tissues
the equilibrium of environment of chronic periradicular • Cellulitis of the area
lesion gets altered; inadvertent entry of micro-organism • Radiographic picture of chronic lesion
and the debris into the periapical tissues subsequently • Pulp vitality tests are negative
leads to acute inflammation (the micro-organisms in • Anti-inflammatory analgesics and antihistamines are effective
chronic lesions remain in equilibrium with the
surrounding environment). 2. Chronic Periradicular Lesions
The periradicular lesions mainly develop due to the
Signs and symptoms infected pulp. As the micro-organisms grow and
• Swelling; acute and spontaneous multiply, they start extruding into the periapical area.
• Cellulitis of the area (Fig. 6.3)
6 • Recent history of initiating root canal treatment
• Patient in discomfort; facial asymmetry
When bacterial infection or by-products of the micro-
organisms enter periapical tissues, the patient's defense
usually cope with the irritants. If the micro-organisms

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 Diseases of Periradicular Tissues 69

are virulent and sufficient in number, acute inflamma-

tion (acute apical abscess) sets in; however, in case,
micro-organisms are less virulent and/or less in
number, the inflammation usually turns into a chronic
lesion. If the source of the irritants is not removed, the
periapical tissues are continually exposed to these
bacterial irritants. The initial acute inflammation, as
the time passes, may become chronic. Healing of the
periradicular lesion takes place only when the
continuous extrusion of the micro-organism is stopped
by performing the endodontic treatment procedure.
Occasionally, however, an area within a chronic
inflammatory reaction may exacerbate (flare up)
producing a focus of acute inflammation. If no treat-
ment is initiated, the inflammation progress; the
epithelial cell rests of Malassez, which are present in a
the apical area, start proliferating and the lesion turns
gradually into a granuloma. As the granuloma increases
in size because of the proliferation of cells within, the
central mass starts liquefying and forms an individual
small cystic spots. As these cystic spots grow, they
coalesce eventually and form a big cystic lesion.
Since, periapical chronic inflammation is long-
lasting and is stimulated by continual irritation;
different disease entities are possible.
The chronic periradicular lesions are:
a. Chronic apical/alveolar abscess (suppurative apical
periodontitis)
b. Periapical granuloma
c. Periapical cyst b
d. Apical scar
Fig. 6.4 (a) Chronic apical abscess (sinus in oral mucosa);
e. Condensing osteitis (b) Sinus tract being checked with gutta-percha

a. Chronic Apical/Alveolar Abscess

(Suppurative Apical Periodontitis)
Chronic apical/alveolar abscess is a long standing, low
grade infection from within the root canal space that
has resulted in an abscess.
Etiology
Chronic apical/alveolar abscess has a pathogenesis
similar to the acute apical/alveolar abscess, that is,
pulpal necrosis. The abscess may burrow through bone
and soft tissues to form a sinus tract on to the oral
mucosa (Fig. 6.4a and b) or sometimes, extra-orally
(Fig. 6.5). It may also drain through the periodontium
into the sulcus.
Signs and symptoms
The condition is usually asymptomatic. Such an abscess
is detected only during the routine radiographic
examination or because of presence of the sinus tract.
The sinus tract may be lined partially or completely by Fig. 6.5 Extra oral sinus
6

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 70 Essentials of Endodontics

epithelium surrounded by inflamed connective tissues. Treatment

The sinus tract prevents exacerbation or swelling by The routine endodontic treatment eliminates infection
providing continual drainage of the purulent exudates. from the root canal. The sinus tract also resolves
following root canal treatment. The extraoral sinus
Diagnosis
opening tract may need be surgically excised. Prognosis
The patient presents with past history of sudden sharp
is usually favourable.
pain which has subsided and not recurred. Clinical
examination may show a large open carious lesion or
Chronic apical/alveolar abscess: Key features
large leaky restoration under which the pulp might
• Long standing non-vital teeth
have necrosed.
• Pulp necrosis elements slowly and continuously irritating; turn
Usually, there is no pain on percussion and no to chronic abscess
tenderness on palpation.
• Usually asymptomatic
The tooth does not respond to vitality tests. • Mostly associated with sinus tract formation; may be mucosal
Radiographic features or extraoral skin
The radiograph shows a diffuse area of bone rarefaction; • Vitality tests negative
however, it is not a definite diagnosis. Origin of sinus tract • Conventional root canal treatment preferred
can be diagnosed by putting gutta-percha cone in to the • Surgical excision of extraoral sinus, if need be
sinus and getting a routine periapical radiograph (sinus • Source of sinus tract can be diagnosed by putting guttapercha
tracing, Fig. 6.6a and b). Accurate diagnosis can only be in the tract and getting it radiographed (sinus tracing)
confirmed by histopathological examination of the lesion.
b. Periapical Granuloma
Periapical granuloma is a mass of chronically inflamed
granulomatous tissues at the root apex resulting from
pulp necrosis and extrusion of the micro-organism and
their toxins into the periradicular tissues.
A granuloma contains granulation tissues and
chronic inflammatory cells infiltrating its fibrous
connective tissue stroma. This is why the term
‘granulomatous’ rather than ‘granulation’ is used in
referring the granuloma.
A granuloma may be seen as a chronic low grade
defensive reaction of the alveolar bone to the irritation
from the necrosed pulp. The granulomatous tissues
may vary in size from a fraction of millimeter to a
centimeter or even larger. It may consist of fibrous
a
capsule which is continuous with the periodontal
ligament and a central portion full of loose connective
tissues and blood vessels. It is characterized by the
presence of lymphocytes, plasma cells, mononuclear
and polymorphonuclear cells. The epithelial cells rest
of Malassez are also seen within the periodontal
ligament, which are derived from the Hertwig’s
epithelial root sheath.

Etiology
The granuloma is developed from infection/irritation
from necrosed pulp; subsequently stimulating cellular
reaction at the periapex.

Signs and symptoms

6
b

Fig. 6.6 (a) Sinus tracing in mandibular first molar, (b) Sinus It is usually asymptomatic, except in cases where it
tracing in maxillary premolars breaks down and undergoes suppuration.

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 Diseases of Periradicular Tissues 71

Diagnosis Histopathological features

The condition is generally discovered during the routine The lesion is characterized by predominance of lympho-
radiographic examination. The involved tooth is not tender cytes, plasma cells and macrophages surrounded by
on percussion. The mucosa overlying the apex of the relatively uninflamed fibrous capsule. The surrounding
concerned tooth may or may not be tender to palpation. coverage is made up of collagen, fibroblasts and rich
The tooth does not respond to pulp vitality tests. vascular network (Fig. 6.8). As the inflammatory
reaction continues, the exudates collect at the expense
Differential diagnosis of the surrounding alveolar bone. At the periphery,
A granuloma cannot be differentiated from other fibroblasts actively build fibrous wall. The alveolar bone
periradicular lesion unless the tissue is evaluated at the periphery may show resorption due to the
histopathologically. presence of osteoclast cells (neutrophils cause localized
tissue destruction, stimulating osteoclasts, which cause
Radiographic features resorption of bone; periodontal ligament space widens
Initially, periodontal ligament thickening is a common and radiolucency develops). Prolonged inflammation
finding. The tooth shows well-defined area of rare- without any treatment stimulates resorption of bone
faction at the periapex and there is break in the continuity in the affected tooth, resulting in loosening of the tooth.
of the lamina dura (Fig. 6.7a). Root resorption may also
Treatment
be seen at the apical area (Fig. 6.7b).
The conventional root canal therapy is the treatment
of choice. The patient is evaluated periodically to
observe the resolution of periradicular radiolucency.
Usually, the healing and establishment of normal
periradicular architecture is achieved in 6 months to
1 year. Surgical intervention may be necessary, if not
healed.
Prognosis is good.

Periapical granuloma: Key features

• Sequelae to chronic pulpal infection (long standing non-vital tooth)
• Mostly asymptomatic
• No pain on percussion (pain only if it turns to acute stage); no
tenderness on palpation
• Chronic inflamed tissue collected at root apex; plenty of cells
a and fibrous tissue
• Loss of continuity of lamina dura; well-defined area of rarefaction
• Conventional root canal therapy is effective
• Prognosis is good

Fig. 6.7 (a) Periapical granuloma in mandibular first molar;

(b) Periapical granuloma in mandibular anterior teeth;
(Note: Apical resorption) Fig. 6.8 Microphotograph of pyogenic granuloma (H&E x 40)
6

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 72 Essentials of Endodontics

c. Periapical Cyst swelling. The symptoms of necrosed pulp are, however,

Periapical cyst is a chronic inflammatory response of evident.
periapex that develops from a pre-existing granulo- Diagnosis
matous tissue. It is characterized by a central fluid filled The tooth may not respond to vitality tests; only radio-
epithelium lined cavity surrounded by granulomatous graphs are helpful. On radiographic examination, there
tissue and peripheral fibrous encapsulation (Fig. 6.9). is loss of continuity of lamina dura with an area of rare-
Periapical cyst is an acute inflammatory cyst with a faction.
distinct pathologic cavity completely enclosed in an
epithelial lining (no communication with the root Differential Diagnosis
canal); whereas, periapical pocket cyst is an apical The radiograph can be helpful in identifying whether the
inflammatory cyst containing a sac like epithelial lined lesion is granuloma or cyst. If a lesion is radiographically
cavity (communication with the root canal). Cyst may hazy, it is a granuloma; whereas, a well circumscribed
also develop after tooth extraction at the site of lesion with sclerotic border is a cyst (Fig. 6.11a and b).
extraction (Fig. 6.10).
Signs and symptoms
A periradicular cyst may not present any specific
symptom. It may become large enough and present as

Fig. 6.9 Lateral periodontal cyst

6 Fig. 6.10 Residual cyst after tooth extraction

b

Fig. 6.11a and b Periapical cyst (radiographic appearance)

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 Diseases of Periradicular Tissues 73

The radiographic picture of a small cyst may not be develops containing fluid along with number of cells
differentiated from that of a granuloma. Although in different stages of degeneration.
positive differentiation between cyst and granuloma
Treatment
cannot be made from radiographs, certain features may
suggest presence of cyst: The periapical cysts have least potential for healing
without surgical intervention as long standing cysts
• Cyst is larger than a granuloma.
show little evidence of granulomatous tissue. Treatment
• May cause spread of adjacent roots due to continuous
involves root canal treatment of involved tooth
pressure from cystic fluid.
followed by surgical removal of the cystic lesion
• A radiopaque band usually encircles the radiolucent (marsupialization).
area.
When a periradicular lesion is presented radio- Periapical cyst: Key features
graphically, it may not be a true cystic or granulo- • Chronic inflammatory response of granulomatous tissues at
matous lesion; rather, it is a mixed lesion containing the root apex
the elements of both the cyst and the granuloma. The • Swelling can be palpable at apex (small cysts are not palpable)
lesion can therefore be: • Negative response to vitality tests
• Cyst • A definite radiographic band encircling the radiolucent area
• Predominantly cystic with some granulomatous is a diagnostic feature
patches • A fluid cavity filled with cells at various stages of the cyst
development
• Granuloma
• Surgical intervention (excision of cyst) is the treatment of
• Predominantly granulomatous with few cystic choice
patches
Dystrophic calcifications may be seen in long The recommended guidelines for treatment of
standing cysts. Rarely, cyst may elevate the osseous periapical lesions are tabulated in Table 6.2.
floor of the sinus and protrude into maxillary sinus.
d. Condensing Osteitis
Histopathological features
Condensing osteitis is recognized by a well-defined
A cyst shows inflammation in periradicular tissue along
radiopacity at the apex of a non-vital tooth.
with proliferation of epithelial cell rests of Malassez
(Fig. 6.12). In chronically inflamed connective tissue, Inflammatory lesions of the periapical region
inadequate nutrition to epithelial cells may lead to their generally result in localized bone destruction and its
degeneration and death. Intercellular fluid gives the replacement with inflammatory tissues. In some cases,
epithelial cells a sponge like characteristic (spaces these inflammatory lesions may result in bone deposi-
between cells increase). A definite central cavity tion. When this happens, a radiopacity appears on radio-
graphic examination; it is known as ‘condensing osteitis’.
Condensing osteitis is caused by the same irritants
(necrotic pulps) that cause other types of periradicular
inflammatory disease. It is observed more often in
children and teenagers than in adults. Increased

Table 6.2 Recommended treatment for periapical lesions

Periapical lesions: Recommended
characteristics treatment
Lesion diameter less than Conventional root canal
5.0 mm treatment; periodic follow-up
Lesion diameter 5.0–10 mm Conventional root canal
(endodontic diagnosis) therapy; periodic follow-up for
long duration
Lesion diameter more than Surgical intervention; if not
10 mm feasible, resinifying therapy

6
No healing even 3 months Re-treatment; may opt for
Fig. 6.12 Microphotograph of radicular cyst (H&E x10)
after root canal treatment surgical intervention (retro-
illustrating stratified squamous epithelium in arcading
grade approach)
pattern and connective tissue

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 74 Essentials of Endodontics

resistance and more abundant blood supply are the

usual explanations. Intraoral examination cannot detect
condensing osteitis. The patient may have experienced
pain and discomfort in the past, which subsided with
time.
Radiographic features
The radiographic features are the most characteristic
features of condensing osteitis. The lesion is marked by
a periapical radiopacity (Fig. 6.13). The radiopacity is
usually well-circumscribed; it may be demarcated from
the surrounding bone by a narrow radiolucent border.
Histopathological features
Presence of bony tissue intermixed with a fibrous
connective tissue stroma along with chronic inflamma-
tory cells are the main histopathological features.
Treatment Fig. 6.14 Apical scar
The treatment of condensing osteitis is the same; root
canal treatment as recommended for other inflamma- by the persistence of a well-defined radiolucency in the
tory periapical lesions. Since the lesion may resolve with periapical regions following treatment of chronic apical
conservative means, surgical intervention may not be periodontitis. A scar can also form after periapical
necessary. Extraction would be the last choice. surgery (Fig. 6.14).
In majority of cases, the void created by lesion-
Condensing osteitis: Key features removal is filled with normal bone with time. In few
• Long standing non-vital tooth cases, the void may get filled with fibrous connective
• Prevalent in young permanent teeth tissue producing a scar. This occurs most frequently
• Chronic inflammation may occasionally lead to condensation when both facial and lingual cortical plates have been
of bony tissues along with fibrous connective tissue lost. The scar appears as radiolucent area. The periapical
(radiopaque on radiograph)
radiolucency creates a doubt whether the lesion has
• No pain on percussion
healed or the lesion recurred due to failure of the root
• Patient feel slight discomfort
canal filling. The size of radiolucency should be
• Conventional root canal treatment is effective; if not, extraction
evaluated periodically along with other signs and
e. Apical Scar symptoms to differentiate between healed and failed
cases. Retreatment is usually not required.
Chronic periapical lesions are treated in routine, both
surgically and non-surgically. Apical scar is recognized
B. PERIRADICULAR LESIONS OF NON-ENDODONTIC
ORIGIN
Periradicular lesions, though commonly linked with
pulp infections, may also develop from the remnants
of odontogenic epithelium. It has been established that
approximately 10–12% of periapical lesions have non-
endodontic origin. In such cases, biopsy and histological
evaluations can be helpful. The indications of biopsy
are tabulated in Table 6.3.
The characteristic features of periradicular lesions of
non-endodontic origin are:
• Vital teeth
• Intact lamina dura
• Distinct radiolucency around periapex
6 Fig. 6.13 Condensing osteitis in mandibular molar
• Organized bone loss/hard tissue loss
• Biopsy confirms the diagnosis

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 Diseases of Periradicular Tissues 75

Table 6.3 Indications for biopsy of periapical lesions

• Lesion adjacent to the root apex of vital tooth
• Persistent periapical lesion even after one year follow-up of
root canal treatment
• Lesion with irregular radiolucency
• Lesions effectively causing mobility without periodontal
disease
• Lesion, which separates from root apex by changing
radiation angle
• Lesion with unusual symptoms
• Progressively growing lesion with history of malignancy a

Most of the non-endodontic periradicular lesions are

cystic in nature or of benign jaw lesions. The common
ones are:
i. Traumatic bone cyst: Traumatic bone cyst is the fluid
containing cavity in the jaw bone, which may not
have the epithelial cover. The lesion usually mimics
chronic periapical inflammatory disease (Fig. 6.15).
The involved tooth is vital, without any external
resorption. The recommended treatment is the
surgical excision.
ii. Odontogenic keratocyst: Odontogenic keratocyst
arise from the cell rests of dental lamina. The lesion b
is commonly seen in young individuals between Fig. 6.16 Odontogenic keratocyst: (a) Bilateral; (b) At an
20 and 40 years of age. The lesion mainly involves angle
the posterior area of the mandible (ramus and
body) (Fig. 6.16a and b). The lesion is mostly iii. Calcifying odontogenic cyst: Calcifying odontogenic
asymptomatic; however, a few cases may present cyst, is mostly asymptomatic and frequently seen
with pain and/or swelling. The absence of caries in anterior region of both the jaws (Fig. 6.17).
and/or pulp involvement can help differentiate Radiographically, the cyst presents with well-
this lesion from apical periodontitis. Enucleation defined radiolucency with occasional diffuse
is the treatment of choice. Since recurrence is radiopaque areas. Ghost cells have been seen
common, long-term follow-up is mandatory. within the epithelial coverage. Enucleation is the
treatment of choice.
iv. Nasopalatine duct/cyst: Nasopalatine duct/cysts are
usually asymptomatic; rarely, may present with

Fig. 6.15: Traumatic cyst Fig. 6.17 Odontogenic cyst

6

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 76 Essentials of Endodontics

pain and/or swelling. The cystic lesion is often

confused with periapical lesion, especially when
the lesion is exhibited over the apex of maxillary
central incisors. The teeth are vital and the
radiolucency may change site with radiographs at
different angles. Surgical enucleation is preferred
treatment.
v. Periapical cemental dysplasia (cementoma): Periapical
cemental dysplasia (cementoma) is due to
proliferation of connective tissues within the
periodontal membrane. It usually involves the
Fig. 6.18 Ameloblastoma
periapical areas of mandibular anterior teeth. The
lesion is asymptomatic. The initial stage of the
lesion (well-defined unilocular radiolucency exhibit multilocular radiolucency with soap-bubble,
around root apex with loss of lamina dura) is spider-web or honey-comb shape appearance.
similar to the endodontic periapical lesions Variable resorption of bony cortex may be seen
(granuloma/cyst). As the lesion grows, radiopaque (Fig. 6.18). The tumor is resected completely along
components are seen within the radiolucent areas with additional resection of margins beyond the
(mixed radiolucent and radiopaque). Finally, the radiological limits of the tumor.
lesion becomes completely radiopaque. Histo- ix. Giant cell granuloma: Giant cell granuloma
pathological evaluation is important to diagnose frequently involves anterior segment of jaws.
the lesion. Radiographically, the lesion presents a well-
vi. Cementoblastoma: Cementoblastoma is the benign defined unilocular or multilocular radiolucency.
neoplasm of the jaw (neoplasm of cemental origin). Both slow growing and aggressive (fast-growing)
The slowly growing, asymptomatic lesions usually lesions are prevalent. The involved teeth are vital.
affect mandible than maxilla. The expansion of Periapical curettage is an effective treatment for
cortical plate of bone is the characteristic feature these lesions; however, radicular surgery is
of cementoblastoma. It presents with well-defined required in aggressive type of lesions.
radiopacity with cortical border confined by x. Myxoma: Myxoma is rare odontogenic tumor that
radiolucent margins. These teeth may and may not arises from mesenchymal cells. These are benign
respond to pulp vitality testing (later stages of in nature; however, may aggressively lead to
cementoblastoma affects pulp vitality). Hyper- resorption of adjacent roots. Smaller lesions are
cementosis is the smaller sized cementoma, unilocular, whereas larger lesions are multilocular.
wherein, there is no jaw expansion. Radiologically, the lesion presents with distinct or
vii. Ossifying fibroma: Ossifying fibroma is a benign jaw ill-defined borders. The internal architecture may
neoplasm affecting mainly the posterior region of exhibit irregular calcifications.
the mandible. The lesion is often asymptomatic and xi. Malignant jaw lesion: Several malignant lesions in
rarely swelling of the cortical plates is seen. the periapical region mimic endodontic periapical
Radiographically, diffuse radiopacity is seen lesions. Lesions such as lymphoma, multiple
within a radiolucent area. The lesion is fast myeloma, squamous cell carcinoma, chondro-
growing. Complete excision is the treatment of sarcoma, and osteosarcoma, etc. are to be properly
choice. diagnosed (most of them are misdiagnosed if only
viii. Ameloblastoma: Originating from odontogenic radiological findings are analyzed).
epithelium, ameloblastoma affects mainly the Radiographically, these lesions show ill-defined
posterior region of the mandible. These are benign radiolucency without any cortical border. Periodontal
in nature; however, may aggressively erode the ligament widening and loss of lamina dura are common
adjacent teeth. Mostly, pain and/or swelling may radiological features. It is opined that any unusual
occur. Various types of ameloblastomas have been symptom of bone destruction adjacent to vital teeth

6 recognized [multicystic (solid), unicystic,

extraosseous (peripheral) and desmoplastic]. The
multicystic form is the most common. Radiographs
should be considered for biopsy (Table 6.3). Both slow
and fast growing lesions are to be surgically removed
in consultation with the oncology surgeon.

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 Diseases of Periradicular Tissues 77

BIBLIOGRAPHY 21. Kahler B. Traumatic bone cyst suggestive of a chronic peri-

apical abscess: a case report. Aust. Endod. J.: 2011; 37:73–75.
1. Abbott PV and Yu C. A clinical classification of the status of
22. Khemaleelakul S, Baumgartner JC and Pruksakom S. Auto-
the pulp and the root canal system. Aust. Dent J.: 2007;
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23. Kuc I, Peters E and Pan J. Comparison of clinical and
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3. Abbott PV. The periapical space- a dynamic interface. Aust.
Endod. J.: 2002; 28:96–107. 24. Mehrazarin S, Alshaikh A and Kang MK. Molecular mecha-
nisms of apical periodontitis: Emerging role of epigenetic
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25. Morsani JM, Aminoshariae A and Han YW. Genetic
5. Bhaskar SN. Periapical lesions - types, incidence and clinical
predisposition to persistent apical periodontitis. J. Endod.:
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6. Buonavoglia A, Latronico F and Pirani C. Symptomatic and
asymptomatic apical periodontitis associated with red 26. Nair PN. Apical periodontitis- a dynamic encounter between
complex bacteria: clinical and microbiological evaluation. root canal infection and host response. Periodontol 2000:
Odontology: 2013; 101:84–88. 1997; 13:121–148.
7. Chala S, Abouqal R and Abdallaoui F. Prevalence of apical 27. Nair PN. On the causes of persistent apical periodontics: a
periodontitis and factors associated with the periradicular review. Int. Endod. J.: 2006; 39:249–281.
status. Acta. Odontol. Scand.: 2011; 69:355–359. 28. Ortega A, Farina V, Gallardo A, Espinoza I and Acosta S.
8. Chang CC, Hung HY, Chang JY, Yu CH, Wang YP and Liu Non-endodontic periapical lesions: a retrospective study in
BY. Central ossifying fibroma: a clinicopathologic study of Chile. Int. Endod. J.: 2007; 40:386–390.
28 cases. J. Formos. Med. Assoc.: 2008; 107:288–294. 29. Ostavik D, Kerckes K and Erikson HM. The periapical index:
9. Chapman MN, Nadgin RN, Akman AS, Saito N, Sekiya K a scoring system for radiographic assessment of apical
and Kaneda T. Periapical radiolucency around the tooth: periodontitis. Endod. Dent. Traumatol.: 1986; 2:20–34.
radiologic evaluation and differential diagnosis. 30. Pace R, Cairo F, Giuliani V, Prato LP and Pagavino G. A diagnostic
Radiographics: 2013; 33:e15–32. dilemma: endodontic lesion or odontogenic keratocyst? A
10. Damm DD. Interradicular radiolucency. Lateral periodontal case presentation. Int. Endod. J.: 2008; 41:800–806.
cyst. Gen. Dent.: 2011; 59:395. 31. Peters E and Lau M. Histopathologic examination to confirm
11. Eversike R, Su L and El Mofty S. Benign fibro-osseous lesions diagnosis of periapical lesions: a review. J. Can. Dent. Assoc.:
of the craniofacial complex. A review. Head Neck Pathol.: 2003; 69:598–600.
2008; 2:177–202. 32. Radics T, Kiss C and Tar I. Interleukin-6 and granulocyte-
12. Faitaroni LA, Bueno MR, Carvalhosa AA, Mendonca EF and macrophage colony-stimulating factor in apical periodontitis:
Estrela C. Differential diagnosis of apical periodontitis and correlation with clinical and histologic findings of the
nasopalatine duct cyst. J. Endod.:2011; 37:403–410. involved teeth. Oral Microbiol. Immunol.: 2003; 18:9–13.
13. Fuji R, Saito Y and Tokura Y. Characterization of bacterial 33. Razavi SM, Kiani S and Khalesi S. Periapical lesions: a review
flora in persistent apical periodontitis lesions. Oral Microbiol. of clinical, radiographic and histopathologic features.
Immunol.: 2009; 24:502–505. Avicenna J. Dent. Res.: 2015; 7:e19435.
14. Garcia CC, Sempere FV, Diago MP and Bowen EM. The post- 34. Ricucci D, Mannocci F and Ford TR. A study of periapical
endodontic periapical lesion: histologic and etiopathogenic lesions correlating the presence of a radiopaque lamina with
aspects. Med. Oral Patol. Oral Cir. Bucal.:2007; 12:585–590. histological findings. Oral Surg., Oral Med., Oral Pathol.,
15. Gutmann JL, Baumgartner C, Gluskin AH, Hartwell GR and Oral Radiol., Endod.: 2006; 101:389–394.
Walton RE. Identify and define all diagnostic terms for 35. Ricucci D, Siqueira JF and Lopes WS. Extraradicular infection
periapical/periradicular health and disease states. J. Endod.: as the cause of persistent symptoms: a case series. J. Endod.:
2009; 35:1658–1674. 2015; 41:265–273.
16. Huumonen S and Orstavik D. Radiological aspects of apical 36. Schultz M, von Arx T, Altermatt HJ and Bosshardt D. Histology
periodontitis. Endod. Topics: 2002; 1:3–25. of periapical lesions obtained during apical surgery. J. Endod.:
17. Iqbal M, Kim S and Yoon F. An investigation into differential 2009; 25:634–642.
diagnosis pulp and periapical pain-a PennEndo database
37. Slots J, Nowzari H and Sabeti M. Cytomegalovirus infection
study. J. Endod.: 2007; 33:548–551.
in symptomatic periapical pathosis. Int. Endod. J.: 2004;
18. Jacinto R, Gomes BP and Shah HN. Quantification of 37:519–524.
endotoxins in necrotic root canals from symptomatic and
38. Suomalainen A, Apajalahti S, Kuhlefelt M and Hagstrom J.
asymptomatic teeth. J. Med. Micro.: 2005; 54:77–83.
Simple bone cyst: a radiological dilemma. Dentomaxillofac.
19. Jakovljevic A, Knezevic A and Karalic D. Pro-inflammatory
Radiol.: 2009; 38:174–177.
cytokine levels in human apical periodontitis: correlation with
clinical and histological findings. Aust. Endod. J.: 2015; 39. Torabinejad M, Bakland LK and Linda L. Immunopathogenesis
41:72–77.
20. Jansson I, Ehnevid H, Lindskog S and Blomlof I. Development
of periapical lesions. Swed. Dent. J.: 1993; 17:85.
of chronic periapical lesions. Oral Surg.: 1978; 46:685–699.
40. West, J D.: Endodontic diagnosis. Mystery or mastery? Dent
Today: 2004, 23, 80–87.
6

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Chapter
7
Rationale of
Endodontic Treatment

Physical, chemical or bacterial noxious stimuli can Signs and Symptoms

produce reversible or irreversible changes in the dental The cardinal signs and symptoms of inflammation are:
pulp and periradicular tissues. The changes depend
1. Pain (dolor)
upon duration, intensity and pathogenicity of the
stimulus along with the host’s ability to resist and Pain is due to the action of cytotoxic agents released
subsequently repair the tissue damages. The mild-to- from humoral, cellular, and microbial elements
moderate noxious stimuli to the pulp may produce acting on the nerve endings.
sclerosis of the dentinal tubules, formation of repara- 2. Swelling (tumor)
tive dentin, or reversible inflammation; whereas, Swelling in affected tissues is due to the ingress of
irreversible inflammatory changes caused by severe macromolecules and fluid.
injury can lead to necrosis of the pulp and subsequent 3. Redness (rubor)
pathologic changes in the periradicular tissues. Since
The redness is due to vasodilatation of vessels
the pulp is encased in the rigid hard tissues with
(capillaries filled with more blood).
virtually no space for expansion coupled with limited
portals of entry and exit without any efficient collateral 4. Heat (calor)
circulation, a clear concept of the fundamentals of Heat is produced by vasodilatation of the vessels and
inflammation becomes mandatory for understanding rushing of blood to the affected tissues.
diseases of pulp and their extension to the periradicular 5. Disturbance of functions (immobility)
tissues. The functions are disturbed (loss of functions)
because of the changes in the affected tissue.
INFLAMMATION In an inflamed pulp, as in any other inflamed organ
Inflammation is the sequence of basic physiologic and of the body, all the symptoms are evident; however,
morphologic reactions occurring in the vascular, ‘pain’ and ‘disturbance of functions’ can be recognized
lymphatic, and connective tissues of the body. The clinically.
objective of inflammation is to remove/destroy the
irritants and to repair the damage caused to the tissues. COMPONENTS OF INFLAMMATION
Repair of the tissues depends on the severity of injury The characteristic components of inflammation are as
and host resistance. The injurious agent may cause follows.
reversible or irreversible changes to the tissues. Irrever-
sible changes lead to tissue damage; whereas, reversible A. Cellular Events
changes lead to repair. Removal of the irritants, In the pulp and periradicular tissues, inflammation may
exudates, and cellular debris enhance the reparative be either acute or chronic. These two states can be
process. Fibroblasts from adjacent tissues and capillary recognized only at the histological level and depend
buds from adjacent blood vessels proliferate in the area on predominance of cells in the lesion. The main cells
resulting in the production of new collagen fibers matrix of an acute inflammatory lesion are the polymorpho-
and also rich supply of blood vessels to the area of injury nuclear neutrophils. In chronic inflammation,
to form granulation tissue. The inflammatory process lymphocytes, plasma cells, monocytes, and macrophages
resolves when repair is completed. are predominant. As a rule, no definite demarcation

78

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 Rationale of Endodontic Treatment 79

exists between acute and chronic inflammation. Lesions surrounded by a thin band of cytoplasm containing
usually have both types of cells, with either acute or small granules. Two types of small lymphocytes, i.e. B
chronic cells predominating. cells and T cells, are known. Both these cells are derived
from the pluripotent haematopoetic stem cells. Stem
a. Polymorphonuclear Neutrophils (PMNs) cells are carried by the blood to the thymus to become
The polymorphonuclear neutrophils morphologically immunologically competent T cells. In contrast, B-cells
consist of a nucleus with three or more connected become immunocompetent in the bone marrow.
lobules and cytoplasm containing lysosomal and T cells have a long life span and are the most common
specific granules. They are present during the acute or cells of the lymphocytic series in the blood. They are
early stages of inflammation. Their main function is to responsible for cell mediated immunity and immune
phagocytize bacteria; may also phagocytize and lyse surveillance of an organism. They re-circulate through
fibrin and cellular debris. They are attracted to the area the lymphoid tissues and organs of the body, except
of inflammation by chemotactic factors produced by through the thymus, and are found in the paracortical
bacteria or by complement, and they are the first cells areas of the lymph nodes. When T cells are stimulated
to migrate from the blood vessels. Serum factors of by an antigen, they develop into sensitized T
complement and immunoglobulins called ‘opsonins’ lymphocytes. These T lymphocytes have various
bind bacteria to the surfaces of the polymorphonuclear immunologic manifestations, such as:
neutrophils. During this stage, the bacteria are • Memory T cells: They speed up immunologic reaction
encapsulated in vacuoles that move into the cytoplasm in subsequent encounters with the same antigen
of the polymorphonuclear neutrophils and come in • Helper or suppressor T cells: These stimulate or
contact with lysosomal granules, which degranulate suppress development of the effector T or B cells
and release lysosomal enzymes for lysis of the bacteria. • Effector T cells: They may produce cell-meditated
They have a narrow range of life; usually destroyed at immune reactions; for example, the delayed
the inflammatory site as the tissue fluids fall to a pH of hypersensitivity reaction.
6.5 due to the increased production of lactic acid during
• Lymphokine: The sensitized T lymphocytes also
phagocytosis and its release into the tissues during their
release chemical mediators called lymphokines.
death. Destruction of the polymorphonuclear
Lymphokines may activate macrophages, poly-
neutrophils also causes the release of the proteolytic
morphonuclear leukocytes, and non-sensitized T
enzymes, pepsin and cathepsin, with resulting tissue
cells, or they may produce interferon, which inhibits
lysis. PMNs with the by-products of cellular lysis and
viral replication required by the immune response.
debris, are the principal constituents of pus.
B cells have a shorter life span than T cells. They are
b. Monocytes/Macrophages found more in the cortical areas of the lymph nodes
Macrophages are derived from circulating monocytes. than in the blood. When activated by an antigen, B cells
Immature monocytes in extravascular areas, such as areas become larger cells called plasmablasts, which divide
of inflammation, differentiate into macrophages. Macro- to form plasma cells and memory B cells. The memory B
phages are phagocytic cells that ingest cellular debris, cells speed the immunologic reaction in subsequent
micro-organisms, and particulate matter. They secrete encounters with the same antigen. The plasma cells are
certain mediators of inflammation, such as lysosomal large, oval and round cells with eccentric nuclei
enzymes, complement proteins and prostaglandins. containing chromatic material arranged in a cartwheel
form. The plasma cells produce immunoglobulins,
Macrophages enhance the immunologic reaction by
called ‘antibodies’. B cells are responsible for the
ingesting, processing, and degrading antigen before it
humoral immunity of the human beings.
is presented to the lymphocytes. Their capacity to
remove debris from the area facilitates repair. Macro- The immunoglobulins (antibodies) have five major
phages are the mononucleated cells; may fuse with classes, i.e. IgM, IgG, IgA, IgD and IgE. These are involved
other macrophages to produce a multinucleated giant in different defense reactions such as:
cell at the time of action. • Neutralization of bacterial toxins by antitoxins
• Coating of bacteria by antibodies or opsonization to
c. Lymphocytes facilitate phagocytosis
Lymphocytes appear in the chronic stage of inflamma- • Lysis of bacteria by complement activation
tory reaction, which are related to the immunologic
system of the organism. Small lymphocytes have a
large, spherical or slightly indented nucleus
• Agglutination of bacteria
• Combining of the antibody with viruses to prevent
their entry into the cells.
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 80 Essentials of Endodontics

d. Eosinophils, Basophils and Mast Cells tissue plasma to produce kinins. These kinins, such as
Other cells found in pulp and periradicular tissues bradykinin, produce vasodilatation and increase the
during the inflammatory response are eosinophilic permeability of blood vessels. It also activates the
leukocytes, basophilic leukocytes and the mast cells. fibrinolytic and blood coagulating systems. Fibrinogen
The eosinophils are found largely in allergic and in the inflammatory exudates is acted on by the
parasitic reactions. During the immune response, they Hageman factor to produce fibrin, which confines the
are involved in phagocytosis of the antigen-antibody inflammatory reaction to a limited area. Plasminogen
complexes and in the detoxification of histamine. from the plasma found in the inflammatory exudates
Basophils and mast cells are considered similar cells; is activated to plasmin. Plasmin may activate the
basophils are found in the hemopoetic system, and the complement system, digests fibrin and thereby aids in
mast cells are found in tissues. They both contain the removal of blood clots or fibrin plugs, or it may
granules, which de-granulate and release chemical activate the kinin system. The inactive serum proteins
mediators, such as histamine (a vasodilator) and of complement are also released from the blood in the
heparin (an anticoagulant) that can initiate an inflammatory exudates. Immunoglobulins activate the
inflammatory or an allergic response. complement cascade to produce anaphylatoxin that acts
on mast cells and causes the release of histamine.
B. Vascular Changes Complement activation also results in the release of a
chemotactic factor, which aids in leukocytosis and lysis
The main characteristics of inflammation are the two
of bacteria.
vascular changes, i.e. vasodilation and increased
capillary permeability, which lead to a series of The fluid leaked from the vessels into the tissues
physiologic and morphologic changes in the system. A accumulates to produce edema. The subsequent
brief vasoconstriction is followed by vasodilatation of increase in tissue pressure causes the venules to collapse
the arteries caused by relaxation of the arteriolar and and reduces both the venous drainage and the blood
capillary sphincters. This opens dormant capillary beds flow from that area. The stasis of blood in the venules
and increases the blood supply to the affected area. due to increased viscosity of blood and the increased
Proteolytic enzymes released from injured cells, pressure resistance of the venules cause the leukocytes
bacterial toxins, coupled with traumatic forces are the to migrate from the center of the blood vessels to the
injurious agents that may release histamine from mast periphery. This process is called margination of
cells, facilitating vasodilatation of the vessels. leukocytes. After margination, the leukocytes start
The vasodilatation is accompanied by an increased adhering to the vessel walls, known as pavementation.
rate of blood flow and a decrease in flow resistance. The next step in the inflammatory reaction is the
These changes increase intravascular pressure, and emigration of the leukocytes. The leukocytes are
permeability of capillaries. Histamine enhances the attracted by complement to the site of inflammation
permeability reaction by contracting the endothelial and migrate through the vessel walls by amoeboid
cells of the venules and producing intracellular gaps. movement. This migration process is called chemotaxis.
This process favors the filtration of plasma and The polymorphonuclear neutrophils migrate first,
macromolecules from the venules. The blood plasma followed by the monocytes and lymphocytes.
escaping through the vessel walls is usually less viscous Chemotaxis is also caused by complement,
and contains less protein than blood plasma remaining prostaglandins, kallikrein and bacterial products.
in the blood vessels. In inflammation, the blood plasma Prostaglandins, thromboxanes and leukotrienes are the
that leaks into the tissues and contains plasma proteins mediators of inflammation that are derived from
such as albumins, fibrinogen, and immunoglobulins is membrane phospholipids. Phospholipase, a lysosomal
referred to as ‘inflammatory exudate’. This exudate brings enzyme produced by polymorphonuclear leukocytes,
the chemical mediators and inflammatory cells to the reacts with the cell membrane phospholipids to
inflamed site; dilutes bacterial toxins, thereby reducing produce arachidonic acid, which in turn, produces
the potential of tissue damage and helps to form fibrin prostaglandins, thromboxanes, and leukotrienes. The
to complete the inflammatory reaction. polymorphonuclear neutrophils also produce
Hageman factor or factor XII of the blood clotting lysosomal enzymes, which give rise to chemotactic
system is released into the tissues in the inflammatory substances that attract more leukocytes to the area of
inflammation.
7 exudates. This factor is activated by collagen, damaged
basement membrane of blood vessels, or by an antigen-
antibody complex and reacts with prekallikrein of the
The vascular response continues with the
aggregation of red blood cells in the vessels. This

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 Rationale of Endodontic Treatment 81

aggregation increases the resistance of the blood to flow. hypersensitivity reactions may occur in the
This resistance, along with the increase in blood periradicular area. It is hypothesized that endodontic
viscosity produced by the loss of plasma, causes flare-ups might be mediated by IgE reactions and that
metabolic changes, such as decrease in the oxygen bone resorption is mediated by a lymphokine called
concentration, an increase in carbon dioxide levels and ‘osteoclastic activating factor’. The osteoclastic factor
a lower pH in the inflammatory site. These changes are confirmed the role of immunologic reactions in the
detrimental to the metabolism of the pulpal tissue, as physiology and pathology of the periradicular tissues.
elsewhere in the body, because they prevent the
removal of waste products. The aforementioned C. Tissue Changes
changes may spread inflammation to the adjacent Tissue changes following inflammation are either
tissues; this vicious cycle of inflammation may lead to degenerative or proliferative.
total necrosis of the pulp.
a. Degenerative Changes
Syngcuk Kim’s Hypothetic Model
Degenerative changes in the pulp may be resorptive or
The migration of monocytes and lymphocytes renders
calcific. Thrombosis of the blood vessels and release of
the inflammatory site capable of an immunologic
leukotoxins from the damaged tissue cells lead to
reaction. As the inflammatory reaction progresses,
degenerative changes; subsequently necrosis of pulp.
macrophages necessary to process the antigen, plasma
Another form of degeneration is suppuration. When
cells derived from B lymphocytes and immuno-
the polymorphonuclear cells are injured, they release
globulin/lymphocyte mediators of the immune system
proteolytic enzymes that cause the liquefaction of the
can be found at the inflammatory site. Extravascular
dead tissues resulting in suppuration or formation of
immunoglobulins found in the inflamed pulp tissues
pus.
and plasma cells are predominantly IgG type, although
Three requisites necessary for suppuration are:
IgA, IgE and IgM containing plasma cells are also
present. The presence of these immunoglobulins i. Necrosis of tissue cells
indicates that the pulp possesses the mechanism for ii. Presence of a sufficient number of polymorpho-
immunologic reaction that contributes to pulpal and nuclear leukocytes
periradicular disorders. iii. Digestion of the dead material by proteolytic
The recovery of the pulp to insult can be explained enzymes
by some unique vascular responses. Arteriovenous If the reaction is not intense, because of weak irritant;
anastomoses and ‘U-turn loops’ open in the pulpal the result will be an exudation consisting chiefly of
vasculature, reduce the blood flow to the area of serum, lymph, and fibrin (serous exudates).
inflammation and thereby decrease the vascular All dead cells, particularly polymorphonuclear cells,
pressure. The increased tissue pressure allows the liberate proteolytic enzymes. Since the enzymes digest
return of macromolecules and fluids to the venules. not only the leukocytes, but also the adjacent dead
These two changes return vascular pressure and tissue, it results in abscess formation. Micro-organisms
stimulate the repair process. are not necessary for development of an abscess; a
sterile abscess may result from chemical or physical
Manifestations of Periradicular Inflammation irritation in the absence of micro-organisms.
An inflammatory response may result in partial or
complete necrosis of the pulpal tissue. In such cases, b. Proliferative Changes
the root canal serves as a pathway for the noxious Proliferative changes are produced by mild irritants.
products and antigens to the periradicular area. The Within the same area, a substance acts both as an irritant
inflammatory and immunologic responses in the and a stimulant; for example, calcium hydroxide and
periradicular area also occur in a similar way as in the its effect on adjacent tissues. In the center of the
pulp. On reaching the periradicular area, these noxious inflammatory area, the irritant may be strong enough
products produce granulation tissue in place of normal to produce degeneration or destruction; whereas, at the
periradicular tissues. The periradicular pathologic periphery, the irritant may be mild enough to stimulate
tissues contain polymorphonuclear neutrophils, proliferation. Generally, if the tissue is in apposition,
lymphocytes, plasma cells, macrophages and mast cells, as in the case of an incision for root resection,
along with the immunoglobulins IgG, IgA, IgM, IgE
and complement. In the presence of these anaphylactic,
cytotoxic, antigen-antibody complex, delayed
fibroblastic repair will take place. When a gap is present
between two parts of the tissue, granulation tissue
repair will predominate. Granulation tissue, itself is
7

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 82 Essentials of Endodontics

resistant to infection. The principal cells of repair are

the fibroblasts, which lay down cellular fibrous tissue.
If the collagen fibers get substituted, dense acellular
tissue is formed. In either case, fibrous repair is the
result. Destroyed bone is not always replaced by new
bone, but it may be replaced by fibrous tissue.
Endodontic Implications
The reaction of the periradicular tissues to noxious
products of tissue necrosis, bacterial products and
antigenic agents from the root canal has been described
by Fish’s phenomenon of foci of infection. He experi-
mented with guinea pigs by drilling in the bone and
packing wool fibers saturated with a broth culture of
Fig. 7.1 Zones of reaction (diagrammatic): (a) Infected
micro-organisms. Four well defined zones of reaction pulp, (b) zone of infection, (c) zone of contamination,
(Fig. 7.1) were found (Zones are considered as the basics (d) zone of irritation, (e) zone of stimulation
of inflammatory reaction in any part of the body; so as
in periradicular areas):
1. Zone of infection
1. Zone of infection
This zone is characterized by polymorphonuclear
2. Zone of contamination
leukocytes. In Fish’s study, infection was seen in the
3. Zone of irritation
center of the lesion; micro-organisms were found only
4. Zone of stimulation in that area. The micro-organisms not disposed off by
polymorphonuclear leukocytes were found in
Zone of infection • Presence of micro-organisms
haversian canals or in the fissures made in the bone
• Presence of polymorphonuclear leuco-
cyte cells matrix by the drill.
• Micro-organisms may invade peri-
radicular areas 2. Zone of contamination
• Micro-organisms present in the center This zone is characterized by infiltration of round cells.
of the lesion Around the central zone, cellular destruction, not from
Zone of • Cellular destruction around the central bacteria themselves but from the toxins discharged
contamination zone caused by bacterial toxins from the bacteria was observed. Whether the toxins
• Bacterial toxins may lead to death of were tissue breakdown products or exotoxins was not
bone cells (autolysis) established. In this area, bone cells had died and had
• Infiltration of lymphocytes and round
undergone autolysis, so the lacunae appeared empty.
cells
Lymphocytes were prevalent everywhere.
Zone of irritation • Presence of macrophages and osteo-
clasts
• Bacterial toxins get diluted
3. Zone of irritation
• Normal bone cells and osteoclasts can This zone is characterized by macrophages and
survive osteoclasts. Evidence of irritation farther from the
• Macrophages digest collagen; bone central lesion was observed as the toxins became more
filled with polymorphonuclear cells diluted as the distance increased. In this area, the small
(sign of repair) round cells, normal bone cells and osteoclasts were
Zone of stimulation • Abundance of fibroblasts and osteo- found in small numbers. The collagen framework was
blasts
digested by phagocytic cells, (macrophages), while
• Bacterial toxins get diluted and do not
act as irritant osteoclasts attacked the bone tissue. The interesting
• Fibroblasts laid down collagen fibres; result of their activity is that they open up a gap in the
act as wall of defence around zone of bone all around the center of the lesion; as trees fell to
irritation isolate a forest fire. The space, thus obtained gets filled
• Epithelial rests of Malassez; if stimulated, with polymorphonuclear leukocytes and until that has

7 taken place, the danger of widespread necrosis remains.

can form a cyst, otherwise, granulo-
matous tissue may be observed This area presents the histological picture of prepara-
showing signs of healing
tory activity to repair.

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 Rationale of Endodontic Treatment 83

4. Zone of stimulation spaces. During cleaning and shaping, this objective is

This zone is characterized by fibroblasts and osteoblasts. achieved with inherent limitations of cleaning the
At the periphery, the toxins were mild enough to be a hidden areas occupied by the micro-organisms. Even
stimulant. In response to this stimulation, collagen after the obturation, some species of micro-organisms
fibers were laid down by the fibroblasts, which acted survive; especially in apical third of root canals. The
both as a wall of defense around the zone of irritation possible events in apical area can be:
and as a scaffolding on which the osteoblasts build new i. The apical segment may have ‘vital’ pulp tissue.
bone. This new bone was built in an irregular fashion. Such tissue, over a period of time, may get infected
The basis of Fish’s experiment can be applied to and lead to failure of the treatment. It is established
understand the reaction of the periradicular tissues to that the outcome of treatment would depend upon
a pulpless tooth. The infected root canal is the seat of virulence and the number of bacteria along with
infection. The micro-organisms in the root canal are host resistance.
rarely motile and do not move from the root canal to ii. The apical segment can be blocked by the dentinal
the periradicular tissues; however, they can multiply chips during canal preparation. In case, the
sufficiently to move out of the root canal. As the micro- blockage occurs after canal preparation, or during
organisms gain access to the periradicular tissues, a preparation of vital pulps/non-infected pulp, the
chronic abscess results. The toxic products of micro- dentinal chips can function as a nidus for
organisms and the necrotic pulp in the root canal are calcification and closure of the apical foramen. In
irritating and destructive to the periradicular tissues case of infected pulp, this area of dentinal chips
and together with the proteolytic enzymes released by debris can contain micro-organisms, which may
the dead polymorphonuclear leukocytes, help to affect the outcome of the treatment.
produce pus.
At the periphery of the destroyed area of osseous iii. The apical segment of the canal may remain
tissue, toxic bacterial products may be diluted enough unfilled. It is established that 1.0 mm of unfilled
to act as a stimulant. The toxic products from the root canal may harbor 80,000 micro-organisms; however,
canal are diffused from the apical foramen and destroy in non-infected canal, the free space can be occupied
bone in the immediate vicinity of the root apex. Further by ingrowth of periodontal ligament tissues. If
away, the toxins are so diluted that they act as a infection persists, inflammation will set in and
stimulant and form a granuloma. Fibroblasts then build hinder with the treatment outcome.
fibrous tissue and osteoblasts around it to delimit the iv. The apical segment can be filled with sealers or
area with a wall of sclerotic bone. If, in addition, the pastes. Most endodontic sealers have some
Epithelial rests of Malassez are stimulated, a cyst forms. antibacterial activity; may help eliminate remaining
Micro-organisms are usually transient in peri- micro-organisms. The sealer/paste may get
radicular tissue, even when an area of rarefaction is solubilized or phagocytized and the space is filled
present radiographically. These transient bacteria can by ingrowth of periodontal tissues. One should also
be destroyed by polymorphonuclear leukocytes. keep in mind that such sealer/paste, if extruded
Although this phenomenon explains the development out of apex may cause transient discomfort.
of radiolucent areas as a result of infection of the pulp, It is accepted that the length of instrumentation of
it may not clarify the development of radiolucent areas infected canal is critical; should be cleaned up to the
following trauma. The pulp may be sterile, even then a terminus. It may involve the possibility of over-
radiolucent area may develop because of tissue instrumentation, which can force infected debris into
breakdown products of the pulp that irritate the the periradicular areas.
periradicular tissues. The apical area of the root canal harbors most of the
After the completion of root canal treatment, the micro-organisms, which remain in contact with the host
reservoir of bacteria or noxious products has been tissues through apical foramen and other accessory
eliminated; repair is initiated and the destroyed peri- foramen prevalent in that area. Micro-organisms of the
apical bone heals in time. apical area, especially in infected cases, are predomi-
nantly anaerobic. It has been established that 90% of
Implications of Residual Infection before and after bacterial cells remain anaerobic after 8–12 weeks in the
Root Canal Treatment
One of the objectives of root canal treatment is to
eradicate all types of micro-organisms from the pulp
apical area; prevalent species being Prevotella intermedia,
Prevotella buccalis, Peptostreptococcus anaerobius and
Veillonella parvula.
7

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 84 Essentials of Endodontics

The apical portion of the root canal system is infection. Extraradicular infection can also be due to
considered ‘critical’, with regard to cleaning and the attached bacteria around root tip surface or
obturating the area. The quality and quantity of bacteria independent formation of cohesive colonies within the
remaining in this area, whether can be managed by host body of the periapical inflammation. It is established
defense, is not known to the operator. It is mandatory that the extraradicular infection may be dependent on
to prepare the canal to its apical limits so as to achieve root canal infection (egress of bacteria from the root
‘no-bacteria’ environment conducive for healing and canal) or independent of the root canal infection
repair. (bacterial colonies in the form of biofilm around
To effectively clean and disinfect the apical portion external root tip surface or persistence of certain
of canal, it is recommended to use patency files, which bacteria even after resolution of periradicular
can breach the apical area or even pass through the inflammation).
dentinal debris created during instrumentation. A small It has been hypothesized that a few species of
size file (no. 8 or 10) is placed 1.0 mm beyond the apical endodontic microflora have the ability to challenge the
terminus area in an attempt to remove dentinal debris host defense and subsequently survive independently
from the apical portion of the root canal. It is advised in the inflamed periradicular tissues and cause extra-
that the smaller files should be passively moved radicular infection. Many types of putative pathogens
through the apical constriction area without widening have been detected in persistent extraradicular
the same. It is accepted that patency files keep the apical infections, such as Porphyromonas endodontalis,
foramen patent and unblocked; maintaining control Porphyromonas propionicum, Fusobacterium nucleatum,
over the working length. Treponema spp. and Prevotella spp. A persistent
Since patency files dislodge debris accumulated in periradicular infection caused by Actinomyces spp. is
the apical portion, it is speculated that the debris is ‘periradicular actinomycosis’, which can successfully
pushed into the periapical areas. The extruded debris be treated by surgical intervention.
can play a role in inducing postoperative pain and even As the success rate of non-surgical root canal
persistence of periapical lesions. However, the influence treatment is fairly high, it is presumed that the incidence
of small patency files on the extrusion of debris is of extraradicular infections is quite low. It has been seen
questionable; many authors have opined that passive that much of the persistent infections can be resolved
action of patency files do not allow debris extrusion with retreatment of the root canal system. Higher
and subsequently pain and discomfort. percentage of healing after retreatment proves that the
In case of retreatment of failed root canal treated main cause is located within the root canal spaces. Root
teeth, the persistent infection in the apical portion is canal procedures may sometimes favor establishment
considered as the major cause of failure. Residual micro- of extraradicular infection (extrusion of debris: over-
organisms can be located in instrumented areas and instrumentation), which should be prevented by all
even in dentinal tubules. If these micro-organisms could means, preferably sticking to the accurate working
not be counteracted by host’s defense; and if in length.
sufficient number and virulence, can develop an
inflammatory lesion in the periapical areas. Repair Following Endodontic Treatment
It has been established that enlarging the root canal, The radiographic picture of periapical tissues of a
without disturbing the apical terminus, would lead to pulpless tooth; if normal prior to treatment, should
sufficient removal of micro-organisms and their by- remain normal after the root canal treatment.
products, thereby improving the chances of better Occasionally, immediately after endodontic treatment,
outcome of the treatment. the radiograph may show a slight rarefied area,
indicating a response to previous irritation, whether
Implications of extraradicular infections mechanical, chemical or bacterial. This is generally
The most common form of extraradicular infection is considered a prelude to repair. Repair begins as soon
the acute periradicular abscess, which is the result of as infection is controlled (Fig. 7.2a and b).
egress of virulent bacteria from the root canal. In normal The stages of repair may be described as follows:
circumstances (host response), the periradicular a. Organization of the blood clot
inflammation succeed in preventing micro-organisms b. Formation of granulation tissue: During this stage, the

7 from gaining access to the periradicular tissues;

however, in certain cases, the micro-organisms can
overcome the resistance and establish extraradicular
endothelial loops become canalized by the increased
pressure of the blood and open new channels for the
circulation. Anastomosis of these loops now occurs,

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 Rationale of Endodontic Treatment 85

Osteoblastic activity is stimulated by stresses and

strains, such as exercise of jaw bones during mastica-
tion. If a pulpless tooth is already completely out of
occlusion, the potential for repair of the periapical tissue
is reduced. Moreover, corticosteroids, if given for a
prolonged period, inhibit the fibroblastic activity
during repair and delay the development of granulation
tissue, thus retarding the repair process.
A chronic inflammatory reaction of the periapical
tissue is common in the presence of an infected root
canal. Shortly after the root canal has been sterilized,
the inflammatory reaction subsides, and fibroblasts and
osteoblasts become more prominent. Even though some
periodontal fibers might have detached, reattachment
Fig. 7.2a Preoperative
occurs as the source of infection is removed. Meanwhile,
if areas of resorption have developed on the root surface
in the region of the destroyed bone, they will be
repaired by cementoblasts and these areas will become
anchor points for attachment of new periodontal fibers.
Resorption and deposition of bone may occur simulta-
neously. In fact, new bone may even be deposited on
old one (new lamellae interwoven with old lamellae
can be seen).
It has been observed that when the radiographic
examination showed repair, the accuracy of the
radiographic interpretation is in concurrence with the
histopathologic findings in almost 85% of cases. A
reduction in periapical radiolucency and reappearance
of bone trabeculae are dependable signs of repair.
Fig. 7.2b Signs of healing after root canal treatment The question is often asked whether incompletely
developed young teeth will continue to erupt after root
forming a rich network of small blood vessels. When canal treatment. It has been observed that endodontic
an area of rarefaction is present, this stage has already treatment seldom interferes with tooth eruption.
occurred in most cases. Whether to do root canal treatment before or during
c. Development of scar tissue: This stage is present in the orthodontic movement is also a question that is
soft tissues. Fibroblasts grow along the fibrin strands occasionally asked. Orthodontic tooth movements do
and help to form the protein matrix by laying down not interfere with the physiology of tooth, even during
collagen fibers. Both the fibroblasts and the or after the orthodontic treatment. In most cases, the
capillaries become fewer in number and vascular bands can be left on the teeth because they did not
fibrous tissue or scar tissue is formed. interfere with endodontic treatment. When non-vital
In bone, the process is not different; however, it is teeth are moved with gentle pressure, the tissues remain
complicated because soft tissue is to be converted to normal and the repair process is not disturbed. The
hard tissue. The protein matrix of bone is formed by periodontal ligament is even less likely to be disturbed
osteoblasts, which are specialized fibroblastic cells. The following endodontic treatment, except when
bone matrix fluid is sub-saturated with calcium salts. inflammation occurred during treatment. In such cases,
The osteoblasts produce an enzyme, alkaline it is preferred to elapse at least one week before
phosphatase, which splits off inorganic phosphorous continuing the orthodontic treatment.
from organically bound phosphorous. The increase in Following endodontic treatment, repair generally
phosphate ions form a saturated solution of calcium occurs in 6 months to one year, depending on the
phosphate that is precipitated into the matrix. These
areas of islands in which the calcium phosphate is
precipitated unite to form spongy trabeculae.
intensity of damage prior to treatment. In some cases,
repair may take longer; the area of rarefaction did not
disappear completely even after 8 years of endodontic
7

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 86 Essentials of Endodontics

treatment as reported in few studies (areas refer to as prophylaxis is advised in patients at risk to develop
‘apical scar’). infective endocarditis. Antibiotic prophylaxis should
A persistent area of rarefaction following endodontic also be considered for immunosuppressed patients or
treatment is not necessarily indicative of infection as patients who have undergone surgical procedures in
repair might have been completed by connective tissues the recent past.
rather than by bone regeneration. In some cases, the
connective tissue matures into dense fibrous tissue Endodontic Treatment and Allergic Reactions
instead of bone. Once this occurs, trabeculated bone will Endodontic treatment involves series of biomaterials
not be formed. Clinical cases have been described, in with varying degree of contact with soft tissues and
which an area of rarefaction was present, but histological blood circulation. Endodontics may have limited risk
examination depicted dense avascular fibrous connec- of provoking allergic reactions associated with
tive tissue. Such areas are designated as ‘Apical scar’. materials; however, ingredients of various materials
have been classified as allergens. Materials like iodine,
Endodontic Infections and Systemic Reactions chlorhexidine, sodium hypochlorite, formaldehyde,
The theory of focal infection, as regard causal relation- chloramine, zinc oxide preparation, resin preparations,
ship between oral infections and systemic conditions, etc. have allergenic potential.
remained controversial due to lack of substantial The most frequent allergic reactions have been
evidence. There is no definite evidence that bacteria observed after application of sodium hypochlorite and
from infected root canals can cause bacteremia; formaldehyde solutions. Systemic reactions, both
however, some specific patients may be at risk. immediate and delayed, have been reported in
It has been established that bacteremia can occur as literature. The immediate reactions are based on the
a result of routine activities like chewing, brushing, etc. encounter between the intruding allergens and the
Since bacteremia can occur from daily activities, it is antibodies released by plasma cells. Type 1 reactions
not possible to exactly determine whether the are usually involved; based on release of active
bacteremia emanated from root canal infection or from mediators by interaction between IgE immunoglobulins
other activities. Whatever the origin, bacteremia is in mast cells, eosinophils, platelets and the intruding
usually transient; however, it is prudent to avoid certain allergens. Delayed responses may be elicited by
situations that could predispose to bacteremia, such as haptenic substances, such as metal ions in the
over-instrumentation in endodontics. endodontic materials (cell mediated delayed reactions).
Infected root canals and also oral micro-organisms Metal ions (excluding instruments) are limited to silver
have been considered as potential foci of infection. It is alloy used in core material and as retrograde filling
documented that these foci are co-related with systemic materials. In addition, metal salts may be present in
diseases, such as coronary heart diseases, bacterial endodontic sealers (added to enhance radiopacity).
endocarditis, brain abscess, etc. during endodontic It is hypothesized that minute quantities of chemical
procedures; studies have confirmed that bacteremia substances associated with endodontic therapy may
occur only in case of over-instrumentation and if instru- establish contact with immunocompetent host tissue
ments remain in confines of root canals, bacteremia do via apical foramen. The direct soft tissue contact is
not occur. A few authors, however, opined that limited to the apical end or accessory canals; overfilled
bacteremia can occur even if instrumentation is sealers and retrograde fillings, increase the contact
maintained within the canal system; hypothesizing that considerably.
apical debris extrusion is induced by all instrumenta- It is established that sensitization of non-allergic
tion techniques (quantity may vary). Such debris, if patient by the endodontic materials is least likely;
infected, can get into periradicular tissues and however, allergic reactions in a previously sensitized
subsequently into the blood circulation. individual is possible. The apparently low prevalence
It is established that root canal infection may lead to of such reactions are explained by three factors; small
bacteremia, but whether that bacteremia is sufficient apical exposure, limited possibility of passage through
to cause diseases or subside with time, has not been dentinal tubules and the availability of minute quantity
confirmed (very few bacterial species of root canal of allergens.
origin survive for longer time in other parts of body).
Healing of Sinus Tract
7 Further research is warranted to confirm whether
bacteria from oral cavity can be involved in focal
infections (other body locations); however, antibiotic
Sinus is a tract leading from an enclosed area of
inflammation to an epithelial surface, and is one of the

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 Rationale of Endodontic Treatment 87

sequelae of inflammatory disease. A sinus tract is a

drainage duct for the suppuration produced by
abscesses (Fig. 7.3a and b). The suppuration from the
periapical inflammatory process may be resorbed by
the host organism. Otherwise, it will flow through the
less resistant tissue area, creating winding trajectories.
Then it will spread through the bone marrow,
periosteum, loose connective tissue among the muscle
fascias, and finally drain onto the epithelial tissue
through either a mucosal or, occasionally, a cutaneous
sinus tract. Cutaneous sinus tracts cause discomfort to
the patient due to frequent drainage on the face and an
unpleasant aesthetic appearance. Cutaneous sinus
tracts are seen more often in adults than in children. a
They are usually present on the chin and cheek and
80% of the reported cases are associated with the
mandibular teeth. Cutaneous sinus tracts of dental
origin are encountered more frequently than sinus
tracts of other pathological conditions; therefore, dental
infection must be the primary suspect in the differential
diagnosis of sinus tracts of the face and neck.
Sinus tract adjacent to teeth or near the apex of the
tooth is usually considered to be of endodontic origin
and root canal therapy is the primary treatment to
achieve its healing. However, stoma of a sinus tract may
not always exit opposite the lesion; at times, it may have
associated periodontal lesion and require combined
endodontic periodontal treatment. Rarely, the etiologic
factor may be involving or aggravated by orthodontic b
reasons. Slutzky-Goldberg et al. found chronic Fig. 7.3 (a) Draining sinus; (b) Sinus tract being checked
periapical abscess as the most prevalent cause for the with gutta-percha
origin and existence of the sinus (71.0%) followed by
broken restoration (53.0%). The most frequent site of peripherally, spreading along the whole trajectory, and
orifices was buccal (82.4%), followed by lingual or its surgical removal is necessary.
palatal (12.0%). According to them, lesions mainly
originated from maxillary teeth (63.1%) while Clinical Assessment
mandibular teeth were found responsible for only Clinically the sinus opening resembles a small ulcer,
38.9% cases. The presence of a sinus tract in the oral but its appearance varies according to the phase of the
cavity is usually considered of pulpal origin, but it can periapical abscess. During the active phase, the sinus
also be caused by periodontal disease, however, the tract is patent and discharges pus. Water soluble
prevalence and incidence of periodontal abscess is lesser radiopaque media can be injected into the patent sinus
than periapical abscess. tract or occasionally, the tract may allow the insertion
The sinus tract itself has been treated with several of a gutta-percha cone or a diagnostic probe (Fig. 7.4).
different therapies, ranging from phenol cauterisation
Table 7.1 Draining sinus v/s healed sinus
to apicoectomy combined with fistulous trajectory
curettage. Draining sinus Healed sinus

Currently, cutaneous sinus tracts of endodontic • Sinus is active with pus • Sinus has healed with pus dis-
discharge charge absent
origin, as well as sinus tracts with either mucosal or
nasal drainage, require no special therapy because they • Surrounding mucosa is • Surrounding mucosa presents

7
reddish pink in color normal tissue coloration
heal after appropriate endodontic therapy. A fibrosis
of the sinus tract trajectory is not uncommon, mainly • Gutta-percha point can • Gutta-percha point cannot
be inserted be inserted
in the older sinus tract. In these cases, fibrosis develops

t.me/Dr_Mouayyad_AlbtousH
 88 Essentials of Endodontics

outcome. Oral Surg., Oral Med., Oral Pathol., Oral Radiol.

Endod.: 2003; 96:81–90.
5. Dandakis C, Lamrianidis T and Boura P. Immunologic
evaluation of dental patient with history of hypersensitivity
to sodium hypochlorite. Endod. Dent. Traumatol.: 2000;
16:184–187.
6. Flanders DH. Endodontic patency. How to get it. How to keep
it. Why it is so important. NY. State Dent. J.:2002; 68:30–32.
7. Goldman M, Rankin C, Mehlman R and Santa CA.
Immunological implications and clinical management of
prophylactic endodontic treatment. Compendium: 1989;
10:462–464.
8. Hamann C, Rodgers PA, Alenius H, Halsey JF and Sullivan
K. Cross-reactivity between guttapercha and natural rubber
Fig. 7.4 Sinus tracing with gutta-percha latex. Assumption vs. reality. J. Am. Dent. Assoc.: 2002;
133:1357–1367.
Periapical and lateral radiographs taken at this time 9. Hensten A and Jacobsen N. Allergic reactions in endodontic
will clearly demonstrate the course and extent of the practice. Endod. Topics: 2005; 12:44–51.
sinus tract. Once the periapical abscess has discharged 10. Hensten-Pettersen A, Orstavik D and Wennberg A. Allergic
its contents, it goes into an inactive phase and the sinus potential of root canal sealers. Endod. Dent. Traumatol.: 1986;
tract tends to heal. When there is another exacerbation 1:61–65.
of the abscess, the sinus tract once again becomes patent 11. Kunisada M, Adachi A, Asano H and Horikawa T. Anaphylaxis
and discharges pus. The offending tooth will be non- due to formaldehyde released from root canal disinfectant.
vital and may be tender. It may have a fracture or caries Contact Dermatitis: 2002; 47:215–218.
extending to the pulp, or, the patient will at least give a 12. Orstavik D, Qvist V and Stoltze K. A multivariate analysis of
history of trauma to the tooth or surrounding area. the outcome of endodontic treatment. Eur. J. Oral Sci.:2004;
Treatment is directed towards elimination of the source 112:224–230.
of infection. The offending tooth is removed if it is too 13. Penick EC. Periapical repair by dense fibrous connective tissue
badly/grossly decayed, or if there is extensive loss of following conservative endodontic therapy. Oral Surg., Oral
the surrounding alveolar bone. In most cases, the Med., Oral Pathol.: 1966; 14:239.
sinus tract heals spontaneously if the infected pulp
14. Seltzer S, Soltanoff W, Sinai I, Goldenberg A and Bender IB.
is removed, and the root canal debrided and filled Biologic aspects of endodontics. Part III. Periapical tissue
(Table 7.1). Some chronic sinus tracts heal leaving reactions to root canal instrumentation. Oral Surg., Oral Med.,
behind a small residual scar. Excision of the residual Oral Pathol.: 1968; 26:694–705.
scar may not be required unless its appearance is of 15. Sinai I, Seltzer S, Soltanoff W, Goldenberg A and Bender IB.
concern to the patient. Biologic aspects of endodontics. Part II. Periapical tissue
reactions to pulp extirpation. Oral Surg., Oral Med., Oral
BIBLIOGRAPHY Pathol.: 1967; 23:664–679.
16. Siqueira JF. Strategies to treat infected root canals. J. Calif.
1. Baumgartner JC and Fakler WA. Bacteria in the apical 5 mm
Dent. Assoc.:2001; 29:825–837.
of infected root canals. J. Endod.: 1991; 17:380–383.
17. Siqueira JF. Reaction of periradicular tissues to root canal
2. Bystrom A, Happonen RP, Sjogren U and Sundqvist G. treatment: benefits and drawbacks. Endod. Topics: 2005;
Healing of periapical lesions of pulpless teeth after endodontic 10:123–147.
treatment with controlled asepsis. Endod. Dent. Traumatol.:
1987; 3:58–63. 18. Siqueira JF and Lopes HP. Bacteria on the apical root surfaces
of untreated teeth with periradicular lesions: a scanning
3. Card SJ, Sigurdsson A, Orstavik D and Trope M. The electrone microscopy study. Int. Endod. J.:2001; 34:216–220.
effectiveness of increased apical enlargement in reducing
19. Siqueira JF and Rocas IN. Polymerase chain reaction-based
intracanal bacteria. J. Endod.: 2002; 28:779–783.

7 4. Chugal NM, Clive JM and Spangberg LSW. Endodontic

infection: some biologic and treatment factors associated with
analysis of microorganisms associated with failed endodontic
treatment. Oral Surg., Oral Med., Oral Pathol., Oral Radiol.:
2004; 97:85–94.

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 Rationale of Endodontic Treatment 89

20. Siqueira JF, Rocas IN. Aves FRF and Santos KRN. Selected 24. Sundqvist G and Figdor D. Life is an endodontic pathogen.
endodontic pathogens in the apical third of infected root canals. Ecological differences between the untreated and root-filled
A molecular investigation. J. Endod.: 2004; 30:638–643. root canals. Endod. Topics: 2003; 6:3–28.
21. Siqueira JF, Rocas IN, Favieri A, Machado AG, Gahyva SM, 25. Tronstad L, Barnett F, Riso K and Slots J. Extraradicular
Oliveira JCM and Abad EC. Incidence of postoperative pain endodontic infections. Endod. Dent. Traumatol.: 1987; 3:86.
following intracanal procedures based on an antimicrobial 26. Wu MK, Wesselink PR and Walton RE. Apical terminus
strategy. J. Endod.: 2002; 28:457–460. locations of root canal treatment procedures. Oral Surg.,
22. Stock C. Endodontics-position of the apical seal. Br. Dent. J.: Oral Med., Oral Pathol., Oral Radiol. Endod.: 2000; 89:
1994; 176:329. 99–103.
23. Spangberg LSW and Haapasalo M. Rationale and efficacy of 27. Yusuf H. The significance of the presence of foreign material
root canal medicaments and root filling materials with emphasis periapically as a cause of failure of root treatment. Oral Surg.,
on treatment outcomes. Endod. Topics: 2002; 2:35–58. Oral Med., Oral Pathol.:1984; 54:566.

t.me/Dr_Mouayyad_AlbtousH
Chapter
8
Endodontic Microbiology

The root cause of virtually all diseases of pulp and 85% of the total volume, consists of exopolysaccharides,
periapical tissues is micro-organisms. Knowledge of the proteins, salts and cell material. The morphology of root
quality of micro-organisms coupled with their canal favors this type of growth.
pathological potential is necessary to understand
endodontic disease process and to effectively manage MICROBES IN ENDODONTIC DISEASE
such infections.
WD Miller, the father of oral microbiology, was the first
Molecular biology analysis has established the
researcher to associate presence of bacteria with pulpal
involvement of both gram-positive and gram-negative
disease. Leeuwenhoek, the inventor of a single-lens
bacteria in intraradicular and periradicular infections.
microscope, was the first to observe oral microbiota
In addition to bacteria, fungi, archaea, and viruses have
from dental plaque and from an exposed pulp cavity.
also been observed in intracanal infections. Viruses
usually do not survive in necrotic pulp environment Invasion of the pulp cavity by bacteria is most often
(replication depends upon viable host cells); however, associated with dental caries. Bacteria invade and
human cytomegalovirus and Epstein-Barr virus have multiply within the dentinal tubules. Dentinal tubules
been observed in intracanal infections. range in size from 1.0–4.0 μ in diameter, whereas the
The microbes in the normal oral flora are opportu- majority of bacteria are less than 1.0 μ in diameter.
nistic pathogens, that is, if they gain access to a normal A tooth with a vital pulp is resistant to microbial
sterile area of the body such as dental pulp, they may invasion. Movement of bacteria in dentinal tubules is
produce disease. The steps in the development of an restricted by viable odontoblastic processes, minera-
endodontic infection include microbial invasion, lized crystals, and various macromolecules within the
multiplication and pathogenic activity. The intensity tubules. Caries remains the most common portal of
of the pathogenic activity is dependent upon host entry for bacteria and bacterial by-products into the
response. It has been reported that endodontic bacteria pulpal space.
might be involved in extraoral complications, such as Many studies demonstrated inflammatory reactions
maxillary sinusitis, orbital cellulitis, infective endo- adjacent to the exposed dentinal tubules. Although the
carditis, etc. inflammatory reactions could result in pulpal necrosis,
‘Pathogenicity’ is a term used to describe the capacity the majority of pulps were able to undergo healing and
of a microbe to produce disease; whereas, ‘virulence’ repair. Following trauma and direct exposure of the
describes the degree of pathogenicity. Bacteria have a pulp, inflammation and bacterial penetration may not
number of virulence factors that may be associated with be more than 2.0 mm into the pulp. In contrast, a necrotic
the disease process. Failure in endodontic therapy may pulp is rapidly invaded and colonized. Peritubular and
be due to the persistence of infections. The problem is reparative dentin may impede the progress of the
not of the presence of the bacteria, but the specificity of micro-organisms. However, the empty dentinal tubules,
microbial species. Another important concern is that following dissolution of the odontoblastic processes,
microbes in root canal, despite of growing in aggregate, may allow easy passage of the microbes into the pulp
may form biofilms consisting of a network of different cavity.
micro-organisms. Biofilms are thin layered condensation Microbes may reach the pulp via direct exposure of
of microbes, composed of different bacterial colonies the pulp from restorative procedures or trauma or
distributed in a matrix. The matrix, constituting about from pathways associated with anomalous tooth

90

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 Endodontic Microbiology 91

development. It is established that changes in the pulp

may have correlation with periodontal disease, but
pulpal necrosis occurs only if the apical foramen is
involved. A few authors are of the opinion that bacteria
concurrent in both root canal and periodontal pocket
suggests that the periodontal pocket is the source of
bacteria in root canal infections.
Anachoresis is the phenomenon by which blood-borne
bacteria, dyes, pigments and other materials are
attracted and fixed to specific areas of inflammation Fig. 8.1a Smear showing Acinetobacter (gram-negative
(process by which microbes may be transported in the cocci)
blood/lymph to an area of inflammation). It may be
the mechanism through which traumatized teeth with
intact crowns become infected. The process of
anachoresis has been associated with bacteremia and
infective endocarditis.
Although more than 150 species of bacteria have been
identified in infected root canals, a considerable
variation is observed in different individuals with
distinct clinical conditions (Fig. 8.1a to d).
Most of the bacteria in an endodontic infection are
strict anaerobes. These bacteria grew only in the absence
of oxygen but vary in their sensitivity to oxygen. They
function at low oxidation-reduction potentials and Fig. 8.1b Smear showing Staphylococcus aureus (gram-
generally lack the enzymes superoxide dismutase and positive cocci)
catalase. Microaerophilic bacteria can grow in an
environment with oxygen but predominantly derive
their energy from anaerobic energy pathways.
Facultative anaerobes grow in the presence or absence
of oxygen; possess the enzymes superoxide dismutase
and catalase. Obligate aerobes require oxygen for
growth; possess the enzyme superoxide dismutase and
catalase.
The root canal system is a selective habitat that allows
growth of certain bacterial species in preference to
others. Tissue fluid and the breakdown products of
necrotic pulp provide the requisite nutrients. The
nutrients (polypeptides and amino acids), low oxygen
tension, and bacterial by-products determine the Fig. 8.1c Smear showing Clostridium (gram-positive bacilli)
preferential presence of the bacteria.
A difference exists between the flora of infected root
canals, which are open to environment and the one
which are closed or freshly opened. The flora is usually
polymicrobial, dominated by obligate anaerobic
bacteria. Among aerobic micro-organisms, α-hemolytic
streptococci are the most commonly recovered
organisms. Streptococci mitis and Streptococcus
salivarius are commonly present in infected root canals.
Although absolute correlation could not be made
between any species of bacteria and severity of endo-
dontic infections, several species have been implicated
with different clinical signs and symptoms. These species
Fig. 8.1d Smear showing Escherichia coli (gram-negative
bacilli)
8

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 92 Essentials of Endodontics

include dark-pigmented bacteria, such as, Peptostrepto- Catonella morbid, a saccharolytic obligate anaerobic
coccus, Eubacterium, Fusobacterium and Actinomyces. gram-negative rod associated with marginal perio-
It is established that Prevotella nigrescens is the dontitis, has been found in about 1/4th of the cases of
commonly identified dark pigmented bacteria from root primary endodontic infections. Other bacteria detected
canals and periapical abscesses of endodontic origin. sporadically in primary infections include Veillonella
The endodontic microbiota presents a high inter- parvular, Eikenella corrodens, Granulicatella adiacens,
individual variation; that is the diversity and abun- Neisseria mucosa, Centipede periodontii, Gemella
dance of microbial species varies from individual to morbillorum, Capnocytophaga gingivalis, Corynebacterium
individual. The commonly prevalent anaerobic bacteria matruchotii, Bifidobacterium dentium and anaerobic
are: Black-pigmented gram-negative anaerobic rods, lactobacilli.
which include species formerly known as Bacteroides Gemella morbillorum and Gemella haemolysans have
melaninogenicus. Later, these bacteria were reclassified been isolated from primary endodontic infections
into two genera: the saccharolytic species (Prevotella) although they do present in persistent infections also.
and asaccharolytic species (Porphyromonas). Prevotella Studies using broad range PCR associated with clone
species frequently detected in primary endodontic library analysis or P-RFLP have indicated that many
infections include, Prevotella intermedia, Prevotella yet-to-be cultivated bacteria can participate in endo-
nigrescens, Prevotella tannerae, Prevotella multi- dontic infection. More than 40–50% of the endodontic
sacharivorax, Prevotella baroniae and Prevotella denticola. microbiota is composed of bacterial phylotypes that are
Out of Porphyromonas species, Porphyromonas yet to be cultivated belonging to genera synergist, TM7
endodontalis and Porphyromonas gingivalis are Dialister, Megapharea, Solobacterium, Olsenella,
consistently present in apical periodontitis lesions. Eubacterium, cytophaga as well as phytotypes related
Fusobacterium species are also common members to family lachnospiraceae.
of the endodontic microbiota in primary infections, with
Fusobacterium nucleatum being the most prevalent. Yet-to-be cultivated species:
Spirochetes are highly mobile spiral-shaped bacteria, • Synergistes oral clone Ba121
falling under genera, Treponema. The most prevalent • Synergistes oral clone BH017
Treponema species are Treponema denticola and Treponema • Synergistes oral clone Wo90
socranskii. • TM7
To differentiate the abscess of periodontal origin from that • Dailister invisus
of endodontic origin, the key factor is the enumeration of • Dialister pneumosintes
spirochetes. The periodontal abscess may contain plenty of • Solobacterium
spirochetes (30–58%); whereas, endodontic abscess contain • Olsenella spp.
less spirochetes (0–10%). • Megaspharea spp. Oral clone CS025
Gram-positive anaerobic rods have also been • Eubacterium oral clone BP1-89
identified. Of these, Pseudoramibacter alactolyticus is • Eubacterium infirmum
the most prevalent gram-negative species. Filifactor • Eubacterium saphenum
alocis, an obligate anaerobic rod is present in about one- • Cytophaga
half of the cases of primary endodontic infections. A • Lachnospiraceas oral clone 55A34
high prevalence of Actinomyces species, Propioni- • Lachnospiraceas oral clone MCE760
bacterium propionicum, Olsenella species, Slackia exigua,
Mogibacterium timidum, and Eubacterium species have Endodontic bacteria, broadly belong to 8 of the 12
also been observed in infected root canals. phyla that have oral representatives, namely firmicutes,
Some gram-positive cocci are frequently present in bacteroides, spirochetes, fusobacteria, actinobacteria,
infected root canals. Parvimonas micra (previously called proteobacteria, synergistes and TM7. Member of the
Peptostreptococcus micros) is present in about one-third two latter phyla and several representatives of the other
of primarily infected canals. Streptococci are most phyla still remain to be cultivated.
prevalent; however, Streptococcus gordonii, Streptococcus
mitis and Streptococcus sanguis are often detected. Rare Endodontic Infections
Enterococcus faecalis has been found in association with
The micro-organisms rarely seen in endodontic infections
root-filled teeth and not frequently in primary infec-
tions. Campylobacter species including Campylobacter are:

8 rectus and Campylobacter gracilis, and gram-negative

anaerobic rods have been detected in primary
endodontic infections; however, their prevalence is low.
Fungi: Candida species have been occasionally found in
primary root canal infections; mainly identified from
persistent root canal infections.

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 Endodontic Microbiology 93

Archaea: It is a highly diverse group of prokaryotes. presence of bacteria in the root canals, especially at the
Archaea, usually not described as a human pathogen, root canal filling stage. This suggests that persistent
has been detected in 25% root canals of teeth with bacteria can survive in treated root canals and sustain
chronic apical periodontitis. periapical tissue inflammation.
Virus: Viruses rarely infect root canals. Of the 8 human It is important to understand some aspects related
herpes viruses currently identified, the human cyto- to the significance of bacteria found in post-treatment
samples. Studies investigating bacteria remaining in the
megalovirus (HCMV) and Epstein-Barr virus (EBV)
canals after chemomechanical procedures or intra-canal
have been linked to pathogenesis of periodontal diseases.
medication provide a prospective view; that is, bacteria
found in these samples have the potential to influence
MICROFLORA OF ROOT FILLED TEETH the treatment outcome. The percentage of most
It has also been established that the outcome of the prevalent bacteria after use of different irrigants and
endodontic treatment is significantly influenced by the intracanal medicaments is depicted in Table 8.1.

Table 8.1 Studies showing percentage of bacteria after use of various irrigants and intracanal medicaments
Study (author Irrigant Intracanal Sample taken Most prevalent Presence of
and year) used medicament after species bacteria
used (percent)
Brystrom and Saline No Chemomechanical Peptostreptococcus anaerobius 70
Sundquist (1981) preparation Lactobacillus species
Bystrom and 0.5% Sodium No Chemomechanical Fusobacterium species 45
Sundquist (1985) hypochlorite preparation Streptococcus species
Eubacterium species
Porphyromonas gingivalis
Prevotella species
Bystrom and 5% Sodium No Chemomechanical Streptococcus species 50
Sundquist (1985) hypochlorite preparation Fusobacterium nucleatum
Bystrom and 5% Sodium No Chemomechanical Streptococci species 75
Sundquist (1985) hypochlorite preparation
and EDTA
Gomes et al 2.5% Sodium No Chemomechanical Streptococci species 80
(1996) hypochlorite preparation Peptostreptococcus micros
Lactobacillus species
Sjögren et al 0.5% Sodium No Chemomechanical Pseudoramibacter alactolyticus 62
(1997) hypochlorite preparation Fusobacterium nucleatum
Campylobacter rectus
Peptostreptococcus micros
Peters et al 2.0% Sodium No Chemomechanical Actinomyces species 58
(2002) hypochlorite preparation Prevotella intermedia
Peptostreptococcus micros
Eggerthella center
Prevotella oralis
Peters et al 2.0% Sodium Calcium Intracanal medication Propionibacterium species 61
(2002) hypochlorite hydroxide Peptostreptococcus micros
Veillonella species
Bifidobacterium species
Capnocytophaga species
Chavez de Paz 0.5% Sodium Calcium Intracanal medication Lactobacillus species 88
et al (2003) hypochlorite hydroxide Enterococcus species
Propionibacterium species
Chu et al (2006) 0.5% Sodium Calcium Intracanal medication Neisseria species 60

8
hypochlorite hydroxide Staphylococcus species
Capnocytophaga species
Actinomyces species

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 94 Essentials of Endodontics

It is established that the major factor influencing the of the root filled teeth. Certain species present in normal
outcome of the endodontic treatment is the presence of endodontic infections are capable to survive under
micro-organisms in the canal at the time of filling. When nutrient-deficient conditions of the root filled teeth. The
no bacteria are recovered from the canal at the filling microflora of teeth with persistent disease can be
stage, healing of apical periodontitis occurs unevent- enterococci, streptococci followed by lactobacilli,
fully. Therefore, the discussion on the topic “One visit Actinomyces, Propionibacterium, Dialister and
versus multiple visits” should focus on how many visits Filifactor. The endodontically treated teeth requiring
are required for the canal to be predictably disinfected. re-treatment have shown a higher prevalence of
Total eradication of bacteria can practically be achieved facultative bacteria, especially Enterococcus faecalis,
after chemomechanical procedures; however, certain instead of strict anaerobes. In untreated root canal,
micro-organisms may be able to survive the chemo- Enterococci constitute about 5.0% of micro-organisms.
mechanical effects. Due to change in root canal environment, this micro-
organism grow in higher and recoverable proportion.
Studies have reported that Enterococcus faecalis has some
EXTRARADICULAR INFECTIONS
special characteristics which allow them to survive under
Apical periodontitis lesions are formed in response to unfavorable conditions. Enterococcus faecalis and allied
intraradicular infections. In most situations, apical species enter the canal during treatment, especially
periodontitis inflammatory lesions succeed in when the canal is left open. It is also reported that
preventing micro-organisms from gaining access to the capacity to withstand wide pH range (up to 11.5) of
periapical tissues. The most common form of extra- intracanal medicaments such as calcium hydroxide,
radicular infection is the apical abscess, characterized make enterococci more viable in root filled teeth. Another
by purulent inflammation in the periapical tissues in characteristic of enterococci is an ability to survive even
response to a massive egress of virulent bacteria from in the environment of low nutritional supply.
the root canal. Most oral micro-organisms are opportu- Another micro-organism which has been identified
nistic pathogens and only a few species have the ability in persistent periapical lesions is Candida albicans. Such
to challenge and overcome host defense mechanism and infections are same in untreated root canals, unless
establish an extraradicular infection. these canals are open to oral environment. Candida
For instance, it is recognized that some Actinomyces species can also grow in low-nutrient environment and
species and Propionibacterium propionicum have the can resist calcium hydroxide medicaments.
ability to participate in extraradicular infections and Actinomyces are also prevalent in resistant retreat-
cause a pathological entity called ‘apical actinomycosis’. ment cases. Actinomyces israelii and Actinomyces meyeri
Some other putative oral pathogens, such as Treponema are more frequently found in resistant cases and may
species, Porphyromonas endodontalis, Porphyromonas involve in periapical actinomyces. Recently, Actino-
gingivalis, Prevotella species and Fusobacterium myces radicidentis has been identified. Propionibacterium
nucleatum, have also been detected in persistent apical propionicus (Arachnia propionica), a facultative anaerobe,
periodontitis lesions. has been associated with persistent infections that
The major cause of failure after root canal treatment do not respond to conventional root canal treatment
is the persistence of micro-organisms in the apical part (Table 8.2).

Table 8.2 Bacterial species commonly found in infected root canals

Gram-positive cocci Gram-positive rods Gram-negative cocci Gram-negative rods
• Streptococcus anginosus • Actinomyces israeli • Veillonella parvula • Prevotella intermedia
• Streptococcus sanguis • Actinomyces naeslundii • Acidaminococcus spp. • Prevotella melaninogenica
• Streptococcus mitis • Prevotella denticola
• Streptococcus mutans • Prevotella buccalis
• Prevotella oralis
• Eubacterium alactolyticum • Neisseria mucosa • Porphyromonas endodontalis
• Eubacterium nodatum • Porphyromonas gingivalis
• Eubacterium limosum
• Enterococcus faecalis • Propionibacterium propionicus • Fusobacterium nucleatum
• Enterococcus faecium • Propionibacterium granulosum
• Parvimonas micra • Lactobacillus spp. • Bacteroides gracilis

8
• Corynebacterium matruchotii • Campylactobacter rectus
• Campylobacter curvus
• Capnocytophaga ochracea

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 Endodontic Microbiology 95

MICROBIAL DIAGNOSTIC TECHNIQUES • Low sensitivity.

Endodontic infections, being polymicrobial in nature, • Strict dependence on the mode of sample transport.
present problems in identification. Previous studies • Samples require immediate processing.
utilized only aerobic cultivation method, ignoring • Identification of anaerobic bacteria may take several
anaerobic bacteria. Recent techniques revealed broader days.
spectrum of bacteria, including viruses, archaea and • Costly, time-consuming and laborious.
fungi etc. • Cultivation of strict anaerobe is difficult.
Several methodologies have been used for identifica-
Reasons for bacterial unculturability
tion of endodontic infections. Sample collection is
important feature for analyzing any endodontic • Lack of essential nutrients/growth factors in the
infection. artificial culture medium.
• Toxicity of the culture medium may inhibit bacterial
Sample Collection growth.
• Other species present in a mixed consortium may
The patient is asked to rinse thoroughly. Isolate the
produce substances inhibitory to the target micro-
tooth with rubber dam. Disinfect both tooth and the
organisms.
rubber dam using 5–10% tincture iodine. The nearby
environment is also kept sterile (a live flame is kept in • Metabolic dependence on other species for growth.
the nearest vicinity of the tooth). To sample a dry canal, • Disruption of bacterial intercommunication systems
a syringe is used to place culture medium into the canal. induced on culture media.
A file is then used to scrape the canal walls to suspend • Bacterial dormancy (a state of low metabolic activity
micro-organisms with the medium. In case of draining that some bacteria develop under stressful conditions/
canals, a paper point can be kept in the root canal for starvation) in bacterial cells do not allow them to
30 seconds and shifted to the medium. A syringe after divide or to form colonies on culture medium.
air aspiration can also be used.
II. Microscopic Examination
A small gauge needle is used to aspirate and collect
sample in case of abscess. If aspiration is not possible, Microscopic examination observes the presence/
the exudates can be collected on a swab. The sample is absence of micro-organisms (infection). Gram stains
quickly transferred to the requisite medium. reveal morphology of microbes; whereas, gram reaction
reveals the gram-positive or negative of microbes. Phase
I. Culture contrast microscopy and dark field microscopy are
better tools for identifying various species of micro-
The type of culture medium influences the results of
organisms, including spirochetes.
root canal cultures. Various media have been used in
endodontics. These include, brain heart infusion broth Advantages
(with and without 0.1% agar), thioglycollate broth, • Supplements culture method.
glucose ascites, cooked meat and Moller’s medium. • Provides rapid information about the flora.
Glucose ascites medium is preferred since agar allows
for growth of aerobes and anaerobes and the ascitic Limitations
fluid stimulates the growth of fastidious organisms; and • Has limited sensitivity (relatively large number of cells
glucose help growth of acidogenic species. are required before they are seen under microscope).
• Has limited specificity (inability to specify micro-
Advantages organisms based on pleomorphic morphology).
• Broad range; unexpected species can be identified.
• Allow quantification of major viable micro-organisms. III. Immunological Methods
• Physiological and pathogenicity studies are possible. The enzyme linked immunosorbent assay (ELISA) and
• Widely accepted. the direct or indirect immunofluorescence tests are
commonly used immunological methods for microbial
Limitations identification.
• Large number of bacterial species cannot be
cultured. Advantages
• Takes few hours to identify the microbial species.
8
• All viable bacteria may not be recovered.
• Once isolated, bacteria require further identification • Low cost.
using a number of techniques. • Can detect dead micro-organisms.

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 96 Essentials of Endodontics

Limitations
• Detect only the target species.
• Low sensitivity.
• Specificity is variable.

IV. Molecular Methods

The commonly encountered micro-organisms are
categorized as:
a. Prokaryocytes (prokaryotes)
• Examples are bacteria, archaea
• Does not have membrane binding nuclei
• No mitochondria and Golgi apparatus present
• Cells have 70s ribosomes (30s–50s subunits
containing 16S rRNA and 23S rRNA molecules)
b. Eukaryocytes (eukaryotes)
Fig. 8.2 Exponential amplification
• Example is fungi
• Membrane bound nucleus • Denaturation of target nucleic acid occurs at 90–95°C,
• Cells have 80s ribosomes (40s–60s subunits whereby DNA strands get separated.
containing 185 rRNA and 25s rRNA molecules). • Primer annealing occurs at lower temperature
The limitations of culture method have led to the (55–60°C) whereby short sequence nucleotide is
introduction of molecular method for identifying annealed to a particular nucleic acid target, resulting
uncultivable species. A number of bacteria, such as in duplex formation.
Bacteroids and Treponemas could be identified from • Extension of primer-target occurs at 70–75°C,
root canals following molecular methods. whereby two duplex strands are formed with the
It has been established that more than 50% bacterial help of enzyme polymerase.
species are uncultivable. Molecular methods could Reverse transcription polymerase chain reaction (RT-
identify many previously unknown pathogens. PCR), a variant of polymerase chain reaction (PCR), is
Molecular approaches rely on the fact that certain genes a technique commonly used in molecular biology to
contain the microbial identity (ribosomes are detect RNA expression (Fig. 8.3). Reverse transcriptase
intracellular particles composed of rRNA and proteins; PCR (RT-PCR), involves exploiting the ability of reverse
sizes are represented by Svedberg (s) units; bacterial transcriptase enzyme to synthesize complementary
cells may have 40s ribosomes with small and large DNA (cDNA) from mRNA transcripts, and then using
subunits genes. These genes are used in molecular PCR to amplify regions of interest. RT-PCR is used to
analysis). clone expressed genes by reverse transcribing the RNA
There are a plethora of molecular methods for the of interest into its DNA complement through the use
study of micro-organisms; main being Polymerase of reverse transcriptase. Subsequently, the newly
chain reaction (PCR) and DNA-DNA hybridization. synthesized cDNA is amplified using traditional PCR.
Various derivatives of PCR technology have been
Polymerase Chain Reaction (PCR)/ developed; the commonly used PCR-derived assays are:
Molecular Amplification i. Multiplex PCR: Multiplex PCR assay permits the
Polymerase chain reaction/molecular amplification is simultaneous detection of different microbial species.
able to amplify one gene to millions of copies of that Two or more sets of primers specific for different
gene. The strategies are, target nucleic acid amplifica- targets are introduced. Primers having similar anneal-
tion, nucleic acid probe amplification and amplification ing temperatures are selected for multiplication.
of the probe signal. PCR has the ability to locate and ii. Nested PCR: This approach provides increased
amplify small quantity of specific nucleotide sequence, sensitivity. The first PCR product is subjected to
which might have lost in large ground of nucleic acid second round of amplification with a separate
(Fig. 8.2). primer set and anneals accordingly. However,

8 The PCR method, based on DNA replication,

involves three steps, viz. denaturation of target nucleic
acid, primer annealing and extension of primer-targets.
Nested PCR has one drawback; high probability of
contamination during transfer of first round
product to the second one.

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 Endodontic Microbiology 97

Fig. 8.3 Reverse transcriptase-PCR (RT-PCR)

iii. Real time PCR: Real time PCR assay allows for Denatured Gradient Gel Electrophoresis (DGGE)
quantification of individual target species and also The genetic fingerprinting of complex microbial
the total number of bacteria in a clinical sample. communities implies extracting and amplification of
The process is fast and contamination of nucleic rDNA using broad range primers and then analyzing
acid is limited as no manipulation is carried out the amplified PCR products by denaturing gradient gel
after initial amplification (overcome disadvantage electrophoresis (DGGE). The DGGE technique is based
of Nested PCR). on electrophoresis of PCR amplified rDNA fragments
iv. Arbitrarily primed-PCR (AP-PCR): AP-PCR is relatively in polysaccharide gel containing increasing gradients
fast PCR based fingerprinting (genomic) technique of DNA denaturants.
used to determine whether two isolates of the same In DGGE technique, multiple samples can be analyzed
species are epidemiologically related. The technique concurrently and possible to compare the structures of
is also known as random amplified polymorphic microbial community of different areas. Temperature
DNA (RAPD). The advantage of AP-PCR includes gradient get electrophoresis (TGGE) uses the same
its ability to furnish specific DNA profiles without principle as of DGGE, but temperature gradient is used
knowing the DNA sequences. Clonal analysis of in TGGE as compared to chemical denaturants in DGGE.
micro-organisms may help to know whether certain
strains of a given species are associated with a Terminal Restriction Fragment Length Polymorphism
disease process and also help tracking the origin of (T-RFLP)
micro-organism infecting a particular site. Terminal restriction fragment length polymorphism, a
v. Broad-range PCR: Broad-range PCR can identify modified version of conventional RFLP, wherein rDNA
several novel, unexpected and uncultivable bacterial from different species in a community is PCR amplified
pathogens directly from the diverse human sites. using primers labelled with fluorescent dye. (The fluore-
The technology is used to investigate the whole scent dyed primer limits the analysis to only the terminal
microbial diversity in a given environment. In PCR fragment of the enzymatic process.) T-RFLP has greater
broad-range technique, primers are so designed resolution than gel based techniques (DGGE/TGGE).
that are complementary to conserved regions of a
particular gene that are shared by a group of micro-
organisms.
The technique effectively assesses genetic differences
between microbial strains and also provide insight into
the structure and function of microbial communities.
8

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 98 Essentials of Endodontics

Advantages of PCR Derived Techniques definitive identification of the organisms. It involves

• Detect both cultivable and uncultivable species. detecting the presence of a gene, or may be a part of it,
• High specificity and accurate identification of strains. or RNA product, that is specific for a particular
• Identification of microbial species takes minimum organisms.
time (fast). In hybridization, single-strand nucleic acid compo-
• Do not require controlled anaerobic conditions nents are hybridized to form duplex-strand, depending
during sampling and transportation. upon the specific design of the hybridization assay
(DNA-DNA, DNA-RNA, RNA-RNA duplex may form;
• Handling and expertise for anaerobic conditions not
however, DNA-DNA duplex hybridization is formed
required.
in routine).
• Samples can be frozen and stored for later analysis.
The process of hybridization includes:
• DNA can be transported easily between laboratories.
• Production of single-strand nucleic acid: Specially
• Detect dead micro-organisms.
designed DNA probes (selection and design of probe
Limitations of PCR Derived Techniques depends upon its intended use; for example, if a
probe is to be used for recognizing only gram-
• Most assays are qualitative/semi-quantitative
positive bacteria, the probe’s nucleic acid sequence
(exceptions: real-time PCR assays).
should be so designed as to identify gram-positive
• Most assays detect only one species at a time (broad- only) are selected depending upon the intended
range PCR analysis may provide information about target nucleic acid. The preparation involves
the identity of virtually all species). enzymatic/chemical destruction of microbial cell
• Like DNA-DNA hybridization, most PCR assays detect coverings to release target nucleic acid (certain cell
only target species (do not detect unexpected species). walls are thick, as in fungi; need more time for
This can be overcome by broad-range PCR assays. chemical/enzymatic action).
• Micro-organisms with thick cell walls, such as fungi, • Hybridization of target and probe nucleic acid:
may be difficult to break open and may require addi- Hybridization involves radiography (mixing in
tional steps for lysis and consequent release of DNA. radiographic film) or non-radioactive means, such
• Some assays can be laborious and costly. as, colorimetry and fluorescence.
• Hybridization assays using whole genome probes In DNA-DNA hybridization technology, the microbial
detect only cultivable species. species are not cultivated, nor their DNA amplified.
• Possibility of false positive and false negative results. The method permits simultaneous determination of the
presence of multitude of bacterial species in single/
DNA-DNA Hybridization multiple samples (check-board method).
The basic principle is the presence of a specific gene/ The main features of microbial identification
particular nucleic acid sequence, interpreted as a methods are tabulated in Table 8.3.

Table 8.3 Microbial identification methods: Main features

Culture method Microscopic examination Immunological method Molecular analysis
• Easily identifies bacterial • Identify location and density • Enzyme linked assays detect • Accurately analyze microbial
number of micro-organisms even dead cells virulence, and gene
expressions
• Effective in study of micro- • Especially useful for some • Low sensitivity, allow detection • Protein expression can esti-
bial virulence and antibiotic fastidious organisms of specific micro-organisms mate the total bacterial load
resistance (spirochetes are observed
under dark-field microscope)
• Shows microbial viability • Allows determination of live • Better sensitivity of microbial
and dead cells detection, taxonomy of micro-
organisms and identification
of pathogenic strains

8
• Facilitate in vitro testing • Allows differentiating micro-
and experiments bial forms, shapes and other
features

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 Endodontic Microbiology 99

MICROBIAL INTERACTIONS IN INFECTED ROOT CANALS A couple of virulent factors, such as polyamines, fatty
acids, capsule and extracellular vesicles also participate
a. Host–Microbe Interactions
in host-microbe interactions.
As the carious activities progress, inflammatory
reaction develops in the pulp. The dentin permeability b. Interaction among Micro-organisms
help carry bacterial products to the pulp.
Another mechanism by which the micro-organisms
Several physiochemical factors in the root canal have modulate the infection process include ability of some
the potential to influence the pathogenicity of bacteria bacteria to inactivate killing mechanism of phagocytic
and may modulate the host defense mechanism. cells. A few bacteria may even genetically vary their
The immune competent cells of pulp provide the surface antigens, causing difficulty for immune system
necessary signals to activate T-lymphocytes, respon- to target these bacteria.
sible for local immune defense. Human dental pulps
have immune competent cells, such as, helper/inducer i. Gene Transfer Systems
T cells, cytotoxic/suppressor T cells, macrophages and Chromosomal DNA usually carries genes necessary for
class II antigen-expressing cells essential for the cell survival. Bacteria also carry accessory genetic
initiation of immune responses. elements, collectively describes as ‘horizontal gene pool’,
When the host immune system is compromised, or which include plasmids, bacteriophages, transposons
the invading micro-organisms are pathogenic, disease and insertion sequences. These provide movement of
can develop (Pathogenicity implies ability of an organism genetic information between different bacteria.
to cause disease in another organism). The pathogens in Plasmids can carry genes that code for antibiotic
any form (bacteria, fungi, virus, etc.) can cause tissue resistance and also genes capable of transfer from one
destruction directly or indirectly. bacterial cell to another. Transposons, a segment of
Endotoxins, enzymes and associated metabolites DNA, can move from one location to another (jump
affect directly; whereas, indirect damage is caused by from one DNA molecule to another, refer to as ‘jumping
disturbing host defense mechanism, induced by genes’). The basic methods by which bacteria can
bacterial components, which include lipopoly- transfer DNA are transformation, transduction and
saccharide (LPS), peptidoglycans (PG), lipoteichoic acid conjugation (cells providing DNA are ‘donor’ cells and
(LTA), fimbriae, exotoxins and certain cell membrane cells receiving DNA are ‘recipient’).
proteins. The degree of depth of pathogenicity (disease The genetic transformation of bacteria involve active
producing ability) is known as ‘virulence’. The uptake of DNA and incorporation into the recipient (the
characteristics of certain virulence factors playing recipient cell gets transformed). Natural transformation
effective role in endodontic infections are: has been observed in gram-positive bacteria, viz.
• Lipopolysaccharide (LPS), also known as endotoxin, Streptococcus mutans, Streptococcus gordonii, and
is a part of cell wall of gram-negative micro- Streptococcus pneumoniae.
organisms. Transduction involves bacteriophages, which have
• Peptidoglycans (PG), a part of cell wall of gram- been isolated from Actinomyces actinomycetemcomitans
positive micro-organisms, react with innate immune and other Actinomyces species in dental plaque and
system inducing inflammatory cytokines in T cells. from E. faecalis in saliva. Conjugation is considered as
• Lipoteichoic acid (LTA), a part of cell wall of gram- the most efficient principle in gene transfer; DNA is
positive micro-organisms, composed of lipids and transferred between cells that are in cell-to-cell
echoic acid; binds with target cells and interact with (physical) contact. Conjugative plasmids and conjuga-
circulating antibodies. tive transposons (jumping genes) are transferred
between cells that are in physical contact. They are
• Exotoxins, released by living cell, can trigger aberrant ubiquitous in gram-negative bacteria as well as in gram-
activation of T cells (can be bactericidal to other positive enterococci, streptococci, staphylococci,
bacteria). Listeria, Bacillus, Clostridium, and Rhodococcus.
• Fimbriae, thin hair like projections made up of Conjugation can occur between bacteria and eukaryotic
proteins found on cell surface of many gram-negative cells. Two groups of conjugative plasmids (pAM 1 and
bacteria; involved in interactions with other bacteria. pIP501) have been recognized in gram-positive bacteria
• Extracellular proteins, released during bacterial cell
lysis; neutralize immunoglobulins and complement
components.
(earlier, studies observed conjugative plasmids only in
gram-negative bacteria). The conjugate plasmids can
transfer from prokaryote E. coli to eukaryote yeast,
8

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 100 Essentials of Endodontics

Saccharomyces cerevisiae, as well as to high eukaryotes are the cells. It is established that biofilms assume a
such as Chinese hamster ovary cells (CHOC). stronger pathogenic potential as compared to organisms
The pheromones are secreted by a potential in planktonic stage. Formation of biofilms challenge the
‘recipient’ cell which ‘activates’ the transfer system of host-defense system and also therapeutic anti-microbial
a potential ‘donor’ cell. Pheromone-responding treatment measures.
plasmids in E. faecalis can carry genes related to The scanning microscopic evaluation observed
antibiotic resistance as well as virulent traits. micro-colonies of micro-organisms in the biofilms that
contain open water channels, within which flow of
ii. Antibiotic Resistance and Virulence associated water and nutrients occurs. Bacteria living in community
with Plasmids life style has several advantages, as bacteria functioning
In addition to antibiotic resistance, a diverse range of together in biofilm are able to degrade large complex
products that may potentially contribute towards nutrient molecule that would not be degraded by an
‘Virulence’ such as cytotoxins, adhesions, and certain individual bacteria. Glycoproteins and other proteins
metabolic enzymes are also often encoded by plasmids. supplied by oral fluids act as source of nutrition for the
Genes on plasmids that encode cytolysins have been microbial communities.
observed in E. faecalis, in most of clinical samples. The sessile micro-organisms in biofilm are 1000 times
resistant to anti-microbial agents as compared to same
iii. Plasmids in the Oral/Endodontic Microbiota
organisms in planktonic form. It is established that the
In the oral microbiota, studies have focused on the physiological properties of bacteria in biofilms are
identification and epidemiology of plasmids in different from those of same bacteria in other
streptococci, black-pigmented anaerobic bacteria, environment (Phenotype of biofilms bacteria is distinct
P. nigrescens, F. nucleatum, oral spirochetes and from that of planktonic bacteria). Oral micro-organisms
E. faecalis. Plasmids were found in 26.7% F. nucleatum have the capacity to adapt to changing environment.
strains. Plasmids were isolated from 7 to 11 oral With respect to environmental heterogenicity within
E. faecalis strains recovered from endodontic patients. biofilm, it is likely that different biofilm harbor different
It is also shown that gene transfer can occur from T. phenotypes of micro-organisms. The diverse physical-
denticola to S. gordonii in experimental biofilms. chemical nature depends upon concentration of
Several studies have reported the positive and nutrients, available of end-products, oxygen and
negative association of bacteria and pairs of bacteria associated growth factors.
with various clinical signs and symptoms. For example,
Another important feature of biofilm is ‘Quorum
positive associations were found between F. nucleatum sensing’, a bacterial cell-to-cell communication
and P. micra, P. endodontalis, Selenomonas sputigena, and mechanism for controlling cellular function in a dense
Campylobacter rectus in teeth with apical periodontitis. aggregates of bacteria. Quorum sensing is useful in
In contradiction, species of Streptococci, P. propionicum, controlling environmental stresses and is involved in
Capnocytophaga ochracea and Vibrio spp. could not show the regulation of several microbial properties. Micro-
any association with other bacteria. organisms like Streptococci, Porphyromonas, Fuso-
bacterium, etc. possess the ability of quorum sensing
BIOFILMS IN ENDODONTIC INFECTIONS and subsequently effectively optimize phenotype
properties of biofilm bacteria in root canals.
Biofilm is defined as ‘a sessile, multicellular microbial
community, characterized by cells that are attached to a The biofilm matrix also contain extracellular DNA
surface and collectively enmeshed in a matrix of polymeric (eDNA). It is reported that eDNA originates from the
substances (usually polysaccharides), their own secretions’. intracellular DNA under conditions where lysis is not
observed. eDNA is mostly due to native secretion and
Literally, biofilm implies a thin layer of condensed
not due to cell death; however, high concentration of
microbes, which may occur in any surface structure in
eDNA is attributed to cell lysis leading to release of
nature. The primary source for organization of this
DNA into extracellular medium.
biofilm is the free-floating bacteria (called planktonic
bacteria), which exist in any aqueous environment. The
Development of Biofilm
excreted products of these bacteria, especially the
adhesive substances like polysaccharides and proteins The stages involved in biofilm formation are:

8 are the pre-requisite for initial attachment of organisms

and also binding different bacteria in the film. The
matrix constitutes approximately 85% of biofilm, rest
Stage I: The first stage involves absorption of organic
and inorganic molecules in the planktonic stage to
the surface, known as 'conditioning layer'. This

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 Endodontic Microbiology 101

conditioning layer is composed of proteins and • Enterococcus faecalis can develop biofilm under any
glycoproteins from saliva and gingival crevicular fluid. condition of root canal (Fig. 8.5a and b); i.e. aerobic,
It promotes adhesion of newer micro-organisms on anaerobic. Nutrient rich (aerobic/anaerobic)
selective bases, influencing the microbial composition environment facilitates E. faecalis to produce typical
of biofilm. biofilms with aggregate of bacterial cells and water
channels; whereas, nutrient deficient (aerobic/
Stage II: Second stage involves the adhesion and co-
anaerobic) environment facilitate formation of
adhesion of micro-organisms to the conditioning layer.
biofilm, which is irregular, unorganized and may
The early colonizers are important and crucial for
contain dead cells along with viable cells.
additional adhesion of micro-organisms.
Mineralization/calcification of E. faecalis biofilms has
Stage III: Third stage involves multiplication and been observed because of interaction of root dentin
metabolism of attached micro-organisms. The charac- structure with E. faecalis (pressure of calcium and
teristics of micro-organisms and the environment phosphate ions help precipitation of bacterial-
influence the growth and multiplication of micro- induced apatite ion mature biofilm). The ability of
organisms in the biofilm (Fig. 8.4). E. faecalis to form calcified biofilm on root canal
Stage IV: Fourth stage involves detachment of micro-
organisms from the biofilm; concurrently with
attachment process. The localized detachment of micro-
organisms starts with initial adhesion and increases as
the number of micro-organisms increase with time. The
detachment of micro-colonies can be because of
‘erosion’ of small portion of biofilm and because of
‘sloughing’, whereby invasive area of biofilm is lost.
The detachment of micro-organisms leads to spreading
and colonizing other sites.

Types of Biofilm
Biofilms in endodontics are divided into (i) intracanal
biofilm, (ii) external root (cementum) surface biofilms,
(iii) periapical biofilm and (iv) biomaterial surface
biofilms.
i. Intracanal Biofilm
The characteristics of intracanal biofilm (attached to
root dentin) are:
• Multilayer biofilm attachment on dentinal wall of
root (attachment thickness vary at different sites) Fig. 8.5a Enterococcus faecalis biofilm (initial stage)
• Major bulk of organisms existed as loose collection
of cocci, rods, filaments, etc.
• Dense aggregates of micro-organisms also observed
• Extracellular matrix of bacterial origin can fill the
spaces between bacterial species and colonies

Fig. 8.4 Stages of biofilm formation Fig. 8.5b Enterococcus faecalis biofilm (late stage)
8

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 102 Essentials of Endodontics

dentin may be a contributing factor for its persis- in equilibrium with host tissues and do not induce
tence. Co-aggregation interactions of other micro- persistent infection; mostly lead to chronic periapical
organisms, especially Fusobacterium nucleatum, also inflammation).
contribute to persistent endodontic infections.
iv. Biomaterial Surface Biofilms
ii. External Root (cementum) Surface Biofilms
Biomaterial surface biofilms implies formation of
The characteristics of external root (cementum) surface bacterial adhesive layers onto a biomaterial surface,
biofilms are: which may be inside or outside the root canal. Such
• Formed on external surface (cementum) of root apex. biofilms are known as foreign body centered biofilm
• Apex of root adjacent of apical foramen is coated with or biomaterial centered infections.
continuous, smooth layer of variety of micro- The characteristic features are:
organisms held together by extracellular matrix • Biomaterial surface biofilm is mainly associated with
material. root canal obturating materials, posts, implants and
• Calcified biofilms on the apical root surfaces have implant supported prosthesis.
also been reported in case of persistent apical • Bacterial adhesion on biomaterial surface involves
infective and delayed healing of periapical lesions. conventional stage, viz. transport of bacteria to
• A few authors opined that external root surface biomaterial surface, non-specific adhesion process
aggregation of bacteria might not be a common followed by specific adhesion phase.
occurrence in teeth with infected pulps (biofilm • Biofilm on root canal obturating materials, may be
composed of cocci, bacilli, and filaments present only intraradicular or extraradicular, involves mainly E.
on teeth with apical periodontitis). faecalis, Streptococcus spp. and Staphylococcus spp. on
gutta-percha points; whereas, Propionibacterium spp.
iii. Periapical Biofilms
and Fusobacterium spp. do not form biofilm on gutta-
The characteristic features of periapical biofilm are: percha (mainly gram-positive facultative anaerobes
• Periapical biofilms may and may not be dependent colonies on gutta-percha points).
on the root canal infections (usually root canal
microbiota are opportunistic pathogens and do not Characteristics of Biofilm as a Community
survive host’s defense in the periapical area).
Considering biofilm as a community of micro-
• Rarely, a few microbial species or their strains may organisms, it should possess the following features:
survive and infect periapical tissues (Actinomyces spp.
• Ability to self-organize (autopoiesis)
and Propionibacterium spp. have been observed in
periapical tissues after endodontic treatment). • Ability to resist environmental disturbances
• The microbial adherence can be as in external root (homeostasis)
surface biofilm or within the body of the inflamma- • Should be effective in association than singly
tory lesion. (synergy)
• Actinomyces spp. usually have fimbrial structure that • Face environmental challenges collectively and not
help in bacterial congregation, which survive in in isolation (communality)
periapical environment by clinging to host cells and The differences between biofilm and planktonic cells
other bacteria, if present (Actinomyces usually live are tabulated in Table 8.4.

Table 8.4 Differences between biofilms and planktonic (free-cells)

Biofilm (community structure) Planktonic (free-cells)
• Community of various micro-organisms co-operating each • Free-moving micro-organisms do not cooperate
other
• Arranged in microcolonies • No such colonies
• Micro-organisms adhered in matrix of lipopolysaccharide/ • No adherence
glycoproteins, etc.
• Intraspecies and interspecies communicate with each other • No such communication

8 • Gradient of pH, nutrient and oxygen tension

• Effective resistance to antibiotics
• No such gradient
• Less resistance to antibiotics

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 Endodontic Microbiology 103

ENTEROCOCCUS FAECALIS:
SIGNIFICANCE IN ENDODONTICS
Enterococcus faecalis (E. faecalis) is the most commonly
implicated micro-organisms in persistent endodontic
infections. It is established that major cause of failure
of root canal treatment is the survival of micro-
organisms in the apical end of root filled teeth. E.
faecalis has been found in high percentage of root canal
failures and is able to survive in the post-filled
challenges.

Characteristics and Strains

Enterococci are gram-positive cocci that can occur
singly or in pairs. They are facultative anaerobes (ability
to grow in absence and presence of oxygen) seen in Fig. 8.6b Enterococcus faecalis
human intestinal lumen and faeces (Fig. 8.6a and b).
They are also prevalent in female genital tracts and are utilizes serum as the nutritional source (originates
normal inhabitant of oral cavity. E. faecalis is associated from periodontal ligaments and alveolar bone). It has
with both primary endodontic infections and persistent the ability to suppress the action of lymphocytes,
infections (prevalence in persistent infections are much subsequently altering the host-immune system. E.
more; nine times more than primary infections). faecalis biofilms are much resistant to phagocytosis and
Enterococci can survive harsh environment, viz. salt antimicrobial.
concentration and alkaline pH. They can survive at
temperature of 60°C (usually 10–45°C is the comfort Virulent factors are summarized as:
zone temperature for E. faecalis). Molecular studies have • Survive prolonged periods of nutritional deprivation
confirmed 23 Enterococci spp. A few subtypes of E. • Binds to dentinal surface and invade dentinal tubules from
faecalis have also been identified by molecular analysis 1000 to 1500 μ depending upon availability of nutrition
techniques. • Suppresses action of lymphocytes, subsequently alters host-
defense response
E. faecalis can survive prolonged periods of
• Utilize serum from alveolar bone and periodontal ligament
nutritional deprivation. It exhibits widespread genetic as nutritional source
polymorphism (possesses protease, gelatinase and • Possesses lytic enzymes like cytolysin and lipoteichoic acid
collagen binding proteins, which help them binding to • Compete with other cells
dentin and invading even the dentinal tubules). It • Helps in biofilm formation and get associated
• Resist intracanal medicament by maintaining hemostasis

E. faecalis biofilms include formation of microcolonies

and adherence of micro-organisms followed by
dissolution of mineral (calcium and phosphate) fraction
from dentin, resulting in initial calcification. Later, E.
faecalis biofilms show carbonated-apatite structure,
which are resistant to eradicate. These micro-organisms
can effectively inactivate antimicrobial agents. E. faecalis
co-aggregates with Fusobacterium nucleatum resulting
in further aggravation of endodontic infections. E.
faecalis biofilms have been observed to be thicker than
biofilms produced by other organisms.

Methods of Eradication
Enterococcus faecalis may enter root canal system during

Fig. 8.6a Colonies of Enterococcus faecalis

treatment, in-between appointments and even after the
completion of the treatment. It is important to prevent
entry of E. faecalis at any phase of the treatment and the
8

t.me/Dr_Mouayyad_AlbtousH
 104 Essentials of Endodontics

treatment regime should be aimed at completely E. faecalis should be prevented from re-entering root
eradicating the micro-organisms from the root canal canal system during or after treatment. Oral rinsing
system. with 2.0% chlorhexidine, disinfecting gutta-percha with
The effective eradication of E. faecalis is carried out sodium hypochlorite before obturating root canals
at each phase of the treatment, mainly during irrigation. along with completely sealing the coronal aspects of
• Preparing apical portion of the root canal to a larger the tooth are the effective measures.
instrument size than initial master apical file (large Potential role of Enterococci in unsuccessful root canal
preparation facilitate removal of micro-organisms treatment
from apical dentin substrate; removes intratubular It has been hypothesized that in periapical infections
dentin, which further allows penetration of anti- that involve E. faecalis, tissue damage may be
microbials). predominantly caused by the host response to the
• Irrigating the root canal spaces with various irrigants bacteria rather than direct damage from bacterial
available. EDTA and citric acid solutions have little products. Viable but not culturable E. faecalis produces
antimicrobial activity; however, their use removes stress proteins in adverse environmental factors, such
the smear layer, which facilitates irrigation solution as sodium hypochlorite, salt, bile salts, acid and heat,
access to dentinal tubules. alkaline stress, glucose starvation, elevated tempera-
– 2.0% chlorhexidine is effective in eliminating or tures, and in tap water.
at least minimizing E. faecalis from the root canal Enterococci have low sensitivity to antimicrobial
spaces and dentinal tubules. agents. It is established that the proficiency with which
– 3.0 to 5.35% sodium hypochlorite, when used in E. faecalis can invade dentinal tubules facilitates
adequate amount, has the ability to destroy E. protection from chemomechanical root canal
faecalis. preparation and intracanal dressing technique. In the
– MTAD (tetracycline isomer, an acid and a presence of human serum, E. faecalis bound better to
detergent) effectively destroys E. faecalis because collagen.
of its anticollagenase activity, low pH and ability Co-aggregation (formed by E. faecalis) interactions
to be released gradually with time. occurring in biofilms may provide an effective means
– Combination of two irrigants has been tried by which E. faecalis remain in root canals; as these
successfully. Combining 2.0% chlorhexidine with biofilm mature, they exhibit the ability to calcify which
calcium hydroxide can achieve pH of 12.8, which may facilitate their stability.
can eradicate E. faecalis (calcium hydroxide alone Virulence factors identified in Enterococci recovered
is not effective to that extent). from infected root canals are: Enterococcus surface
– Other irrigants as ozonated and superoxide water protein and collagen-binding protein, which contribute
and lasers are also effective in eradicating E. to ability to bind the dentin.
faecalis. Stannous fluoride has also shown great Pheromones from E. faecalis, chemotactic for
efficacy. neutrophils may trigger superoxide formation. Overall,
– Intracanal medicaments, such as Metapex (silicone possession of the above ‘virulence traits’ might provide
oil based calcium hydroxide paste containing 38% advantage over other species enabling survival in the
iodoform effectively disinfect dentinal tubules. infected root canals.
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73. Siqueira J and Rocas CI. Molecular detection of black
pigmented bacteria in infection of endodontic origin. J.
Endod.: 2001; 27:563–566.

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74. Siqueira J and Rocas I. Cultivable bacteria in infected root 87. Siqueira JF. Periapical actinomycosis and infection with
canals as identified by 16S rRNA gene sequencing. Oral Propionibacterium propionicum. Endod. Topics: 2003; 6:
microbiology and Immunology: 2007; 22:266–271. 78–95.
75. Siqueira J and Rocas I. Oral Treponemas in primary root 88. Spratt DA. Significance of bacterial identification by
canal infections as detected by nested PCR. Int. Endod. J.: molecular biology methods. Endod. Topics: 2004; 9:5–14.
2003; 36:20–26. 89. Steinberger RE and Holden PA. Extracellular DNA in single-
76. Siqueira J and Rocas I. Peptostreptococcus micros in primary and multiple-species unsaturated biofilms. Appl.
endodontic infections as detected by 16sr DNA based PCR. Environment. Microbiol.: 2005; 71: 5404–5410.
J. Endod.: 2003; 29:111–113. 90. Stuart CH, Schwartz SA, Beeson TJ and Owatz CB. Entero-
77. Siqueira J and Rocas IN. Polymerase chain reaction-bases coccus faecalis: its role in root canal treatment failure and
analysis of micro-organisms associated with failed current concepts in retreatment. J. Endod.: 2006; 32:93–98.
endodontic treatment. Oral Surg., Oral Med., Oral Pathol., 91. Sunde PT, Tronstad L, Eribe ER, Lind PO and Olsen I.
Oral Radiol. Endod.: 2004; 97:85–94. Assessment of periradicular microbiota by DNA-DNA
78. Siqueira J and Rocas IN. The oral microbiota: general hybridization. Endod. Dent. Traumatol.: 2000; 16:191–196.
overview, taxonomy, and nucleic acid techniques. Methods 92. Svensater G. and Bergerholtz G. Biofilms in endodontic
Mol. Biol.: 2010; 666:55–69, infections. Endod. Topics: 2004; 9:27–36.
79. Siqueira J, Alves KRF and Rocas IN. Pyrosequencing analysis 93. Thoma VC, Hiromasa Y, Harms N, Thurlow L, Tomich J
of the apical root canal microbiota. J. Endod.: 2011; and Hancock LE. A fratricidal mechanism is responsible for
37:1499–1503. eDNA release and contributes to biofilm development of
80. Siqueira J, Rocas IN, Cunha CD and Rosado AS. Novel Enterococcus faecalis. Mol. Microbiol.: 2009; 72:1022–1036.
bacterial phylotypes in endodontic infections. J. Dent. Res.: 94. Tronstad L and Sunde PT. The evolving new understanding
2005; 84:565–569. of endodontic infections. Endodontic topics: 2003; 6:57–77.
81. Siqueira JF and Rocas IN. Bacteroides Forsythus in primary 95. Usha HL, Kaiwar A and Mehta D. Biofilm in endodontics:
endodontic infections as detected by nested PCR. J. Endod.: New understanding to an old problem. Int. J. Contemp.
2003; 29:390–393. Dent.: 2010; 1:44–51.
82. Siqueira JF and Rocas IN. PCR-based identification of 96. Vineet RV, Nayak M and Kotigadde S. Association of endo-
Treponema maltophilum T. amylovorum, T. medium and T. dontic signs and symptoms with root canal pathogens: A
lecithimolyticum in primary root canal infections. Arch. Oral clinical comparative study. Saudi Endod. J.: 2016; 6:82–86.
Biol.: 2003; 48:495–502. 97. Waltimo T, Haapsalo M, Zehnder M and Meyer J. Clinical
83. Siqueira JF and Rocas IN. Uncultivated phylotypes and newly aspects related to endodontic yeast infections. Endod. Topics:
named species associated with primary and persistent endo- 2005; 9:66–78.
dontic infections. J. Clin. Microbiol.: 2005; 43:3314–3319. 98. Wang BY, Chi B and Kuramitsu HK. Genetic exchange
84. Siqueira JF and Sen BH. Fungi in endodontic infections. O. between Treponema denticola and Streptococcus gordonii
Surg., O. Med., O. Path.: 2004; 97:632–641. in biofilms. Oral Micorbiol. Immunol.: 2002; 17:108–112.
85. Siqueira JF, Rocas IN, Moraes SR and Santos KR. Direct 99. Williamson A, Cardon JW and Drake DR. Antimicrobial
amplification of rRNA gene sequences for detection of susceptibility of monoculture biofilms of a clinical isolate
putative oral pathogens in root canal infetions. Int. Endod. of Enterococcus faecalis. J. Endod.: 2009; 35:95–97.
J.: 2002; 35:345–351. 100. Zehnder M and Belibasakis GN. On the dynamics of root
86. Siqueira JF. Endodontic infections: concepts, paradigms and canal infections—what we understand and what we don’t.
perspectives. O. Surg., O. Med., O. Pathol.: 2002; 94:281–293. Virulence: 2015; 6:216–222.

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Chapter
9
Diagnosis and
Diagnostic Aids

The success in endodontic treatment depends upon body; who is authorized to identify the disease process
correct diagnosis, meticulous preparation and three- by taking relevant history, performing thorough clinical
dimensional obturation of root canal system. The examination and is able to analyze the data obtained
Hippocratic Oath, ‘do no harm’ should be strictly from various diagnostic aids.
followed by the operator. Dental treatment in any form, The diagnostician should have sympathetic ears to
should never be embarked upon until the diagnosis is hear, eyes to see, hands to feel, nose to smell, brain to
established. Diagnosis is the most critical aspect of analyze and clinical experience to derive proper
patient care since adequate treatment planning depends diagnosis. He/she should have:
on accurate diagnosis. The process of diagnosis involves
• Knowledge of disease process
collection of information, observing signs and
symptoms, thorough clinical examination and accurate • Interest in the subject
interpretation of objective testing. Various scientific • Concern for patient care
devices can be used to gather information and the • Curiosity to find the details
thoughtful interpretation of the collected information • Intuition to suspect unusual
help arriving at diagnosis. An accurate diagnosis is a
result of the synthesis of scientific knowledge, clinical • Patience to finalize the diagnosis.
experience, intuition and also common sense.
PATIENT ASSESSMENT
Diagnosis and Prognosis The moment patient enter the dental clinic, the process
Diagnosis is considered as the cornerstone in the of patient’s assessment starts. The doctor should
practice of healing art. It is the correct determination observe and analyze the patient as regard his/her gait,
and logical appraisal of conditions observed during the posture and attitude. The patient’s dress sense and also
examination, as evidenced by distinct signs and the way of communication at the front office should
characteristics of health/disease. This is accomplished also be evaluated. All these features are carefully
through sensory and mental processes used in observed and managed in a friendly manner; affects
evaluation of the findings observed during treatment outcome.
examination. Diagnosis is defined as ‘the utilization of
scientific knowledge for identifying a diseased process and Personal record
to differentiate it from other diseased processes’. Literally, Patient record is usually maintained for identification,
the art of identifying a disease from its signs and legal and medical record purposes.
symptoms is ‘diagnosis’; whereas, prognosis is pre- This record should have all personal details, medical
determination of the probable course and outcome of history, past dental experience and the patient’s
the disease. expectation. The informed consent should be secured
in one note.
Diagnostician With digitalization, the patient data, fingerprints and
Diagnostician is a qualified person, who has the scientific signature can be kept on a computer; alternatively a
knowledge of normal and abnormal conditions of the scanned sheet can be attached to the patient's file.

108

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 Diagnosis and Diagnostic Aids 109

Social and psychological review swellings related to pulp necrosis and/or

• Attitude of the patient traumatized teeth imply endodontic involvement
• Financial status of the tooth; but, non-odontogenic pain should also
• Patient’s expectations be considered.
• Patient’s motivation. ii. Onset: Chronicity of the problem may indicate
underlying histopathologic changes in the pulp or
Personal history
periradicular tissues. Onset being spontaneous or
• Diet (vegetarian or non-vegetarian): Non-vegetarian provoked, sudden or gradual should also be
diet requires more chewing that may affect teeth and analyzed. (Reversible pulpitis is characterized by pain
muscles of mastication
which is caused by a specific irritant and the pain
• Brushing habits (faulty tooth brushing may lead to subsides when the irritant is removed. In case of
damage to teeth and gums)
irreversible pulpitis, the pain lingers on.)
• Alcohol and smoking habits.
iii. Intensity: Dull, aching, pulsating, throbbing,
Past dental history radiating, stabbing, etc. are descriptions of pain
• Previous visit to a general practitioner and/or usually associated with irreversible pulpal changes.
endodontist After pulp necrosis, the intensity of pain may be
• What procedure was carried out? mild or none; still indicating endodontic interven-
• Frequency of visiting dental surgeon tion. (Diagnosis is a combination of all subjective
• Past dental experience (difficulty in tolerating certain and objective tests.)
procedure) iv. Duration: Episodes of pain of long duration are
• Attitude of the patient towards dental treatment usually associated with irreversible pulpitis or
Occupational history partial pulpal necrosis. Reversible pulpitis is usually
• Occupation may lead to some dental problems, such characterized by pain of short duration.
as: v. Frequency: More frequent the occurrence of painful
– Abrasion cavities in tailors and cobblers due to episodes; more severe the pathologic condition of
pin holding habit in between front teeth the pulp.
– Erosion in acid factory workers. vi. Aggravating factors: Factors like cold, hot, sweet,
Family history sour, chewing, etc. may aggravate pain; viz. dentin
• Assess family attitude towards oral health exposure (sensitivity type of pain), reversible
pulpitis (pain to cold stimulus or sweets).
• Assess inherited problems, as:
– Malocclusion vii. Relieving factors: Factors such as cold, hot water
– Dentinogenesis imperfecta/amelogenesis imper- bath, analgesics, etc. may relieve pain, viz.
fecta, etc. reversible pulpitis (pain relieved by removal of
stimulus), irreversible pulpitis (pain lingering even
Chief complaint after removal of stimulus).
Chief complaint(s) of the patient should be recorded in
patient’s own words which helps the clinician to History of present illness: Key features
concentrate on the problem for which patient seeks • Nature of the problem: Pain, swelling, etc. (endodontic or
dental treatment. non-odontogenic)
The patient must be encouraged to discuss his/her • Onset: When did the problem start?(acute or chronic)
problems for developing good rapport; subsequently • Intensity: How painful is it? (mild, moderate or severe)
adequately diagnosing the disease process. • Duration: How long it hurts? (pain of short or long duration)
“Listen to your patient; presenting you the diagnosis” • Frequency: How often does it hurt?
• Aggravating factors: Cold, hot, sweet, sour, etc.
History of present illness • Relieving factors: Cold, hot water bath, analgesics, etc.
History taking is a very important phase of the
diagnostic procedure. The operator should analyze the Medical history
following aspects:
i. Nature of the problem: Generally the problem is pain,
swelling, and loss of function or esthetics. Pain and
Thorough medical history is mandatory as it affects
dental diagnosis and also the treatment outcome.
Details given in Chapter 10.
9

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 110 Essentials of Endodontics

Clinical Examination • Temporomandibular joint—any deviation, clicking

Clinical examination implies careful inspection and sound, pain in the morning (especially in patients
accurate investigation of the condition prevailing in a with occlusal disturbances and bruxers).
patient. It is ‘hands on’ process of observing both normal • Salivary glands (swelling, blockage, etc.).
and abnormal conditions in the patient’s oral cavity. • Lymph nodes (size, mobility, tenderness).
Vital signs such as blood pressure, pulse rate, • Muscles of mastication (palpation of these muscles
respiratory rate and temperature should be recorded may reveal muscle fatigue, common in patients with
prior to clinical examination. bruxism).
The intraoral and extraoral tissues are thoroughly
examined and properly recorded. The recorded data Intraoral Examination
provides following features: Examination of soft tissues (Fig. 9.1a to d)
a. Provides information for accurate/comprehensive • Buccal mucosa: Any ulceration (lichenoid reaction,
treatment plan white patch etc.)
b. Help in third party communication • Buccal vestibule (swelling or sinus opening)
c. Assessing quality of infrastructure/instrumentation • The intraoral sinus tract should be traced to its
in clinic origin
d. May be required in legal proceedings • Hard palate/soft palate: Swelling, ulceration,
smoker’s palate
e. Useful for forensic matters, if need be
• Frenum: Size and configuration (important during
The recorded data should be: diastema closure)
• Uncomplicated: Should be effective and accurate
means of recording oral conditions (easily under-
stood by others)
• Comprehensive: All oral conditions, both normal
and abnormal along with associated tissues to be
noted
• Accessible: The patient record should be easily
accessible for reference, during and on recall appoint-
ments
• Current: Continually updating the patient’s features
as the treatment is progressed.

SOAP format of recording

• S: Subjective (patient symptoms) a
• O: Objective (signs)
• A: Assessment
• P: Planning of treatment

Extraoral Examination
The operator should examine:
• Eyes—for fear, apprehension and systemic disease
like anemia, etc.
• Facial asymmetry or distentions—for swellings or
other abnormality.
• Lip (competency, ulcerations, presence of mucocele,
9 lip line, mobility, etc.)—provides information for
esthetics.
b

Fig. 9.1a and b Gingival examination

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 Diagnosis and Diagnostic Aids 111

• Floor of mouth and tongue (dorsal, ventral and Examination of hard tissue (teeth) (Fig. 9.2a and b)
lateral aspects) Teeth are recorded using any denotation system.
• Gingiva (color, contour, consistency, surface texture, Number of missing restored, retained and deciduous
size and shape) teeth are noted. Teeth are carefully examined for caries,
• Oropharynx. enamel fracture, discoloration, etc.
The various methods which can be used in
endodontic diagnosis are tabulated in Table 9.1.

c Fig. 9.2a Generalized discoloration

Fig. 9.1c and d Examining the palatal surface Fig. 9.2b Microcracks in mesiobuccal cusp

Table 9.1 Methods used in endodontic diagnosis

Clinical inspection methods Radiographic techniques
• Visual inspection • Conventional radiography
• Magnification • Radiovisiography (RVG)
• Dyes • Xeroradiography
• Palpation • Digital subtraction radiography
• Percussion • Computerized tomography (CT)
• Mobility and depressibility • Magnetic resonance imaging (MRI)
• Periodontal Probing • Cone beam computerized tomography (CBCT)
• Bite test (occlusal pressure test) • C-arm imaging
• Test cavity
• Anesthesia test

9
• Videography/Intraoral camera
• Fiberoptic transillumination
(Contd…)

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 112 Essentials of Endodontics

Table 9.1 Methods used in endodontic diagnosis (Contd.)

Clinical inspection methods Radiographic techniques
Pulp vitality tests Tests measuring tooth temperature
Tests assessing the neural status of pulp • Cholesteric liquid crystal
• Thermal test • Electronic thermography
– Cold test • Infrared thermography (Hughes probeye camera)
– Heat test
• Electric pulp testing
Tests assessing the blood supply of pulp
• LASER Doppler flowmetry
• Pulse oximetry
• Dual wavelength spectrophotometry
• Optical reflection vitalometer
• Photoplethysmography

Newer methods
• Ultrasound imaging
• Computer expert system (COMENDEX)
• LASER optical disc storage

CLINICAL INSPECTION METHODS

1. Visual inspection: It involves visual examination of
teeth and associated structures, evaluating the
following features:
• Color: Discoloration of the teeth, uniform or localized
caries, fractures/craze lines
• Contour: Unusual anatomy, defective restorations,
cervical lesions/non-carious lesions
• Consistency: Caries, resorption, etc.
• Supra-eruption: Extrusion of teeth.

2. Magnification: The use of optical magnification

instruments such as loupes, microscopes, endoscopes
and orascopes enables the operator to magnify a Fig. 9.3 Palpation
specified treatment field beyond that perceived by the
naked eye. • Aids in locating a swelling, intensity and location of
pain
3. Dyes: Use of dyes helps in the detection of caries and • Evaluate presence of lymphadenopathy
fractures. Methylene blue dye, India ink, crystal violet • Evaluate presence of bony crepitus.
and erythrosine red are used to diagnose the presence
of crown or root fractures. 5. Percussion: Percussion implies striking the tooth with
(A very small amount of the dye is placed on a small a quick, moderate blow of low intensity with finger,
cotton pellet and the crown/root is coated with it. The followed by mirror handle to determine tenderness
dye on the surface is washed away; in case of fracture, (Fig. 9.4). The contralateral tooth is percussed prior to
the dye remains within the crack and can be observed the questionable tooth. Percussion evaluates following
through loupes or a dental operating microscope.) features:
• Periodontal status (periodontal ligament)
4. Palpation: Palpation implies moving index finger • Pain on percussion can be due to periradicular
tip around the soft tissues to identify tissue consistency pathosis, fractures, periodontal disease, traumatic
and any discomfort, etc. (Fig. 9.3). The features of
9 palpation are:
• Should be carried out bilaterally at the same time
occlusion, sinusitis (pain in two or more teeth in the
upper jaw), or any other condition that affects the
periodontal ligament.

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 Diagnosis and Diagnostic Aids 113

Grades of mobility
Grade I: Noticeable movement within the socket
Grade II: Lateral movement within 1.0 mm range
Grade III: More than 1.0 mm lateral movement and/or
depressibility
The mobility may be due to apical abscess, perio-
dontal disease, horizontal fracture in the middle/
coronal third of the root, vertical fracture, chronic
bruxism or clenching.

Palpation, percussion, mobility and depressibility check the

integrity of the attachment apparatus; not the condition of
pulp
Fig. 9.4 Percussion

Key features of percussion test are summarized in 7. Periodontal probing: Periodontal probing evaluates:
Flowchart 9.1. • Health of periodontium (Fig. 9.6a and b)
• Furcation involvement, palatogingival groove,
Percussion test: Key features etc.
Positive response • Differentiate disease of periodontal origin from pulp
• Rapid orthodontic movement origin.
• High points on restorations
• Occlusal trauma 8. Bite test (occlusal pressure test): Bite test is useful in
• Lateral periodontal abscess identifying teeth with symptoms of apical periodontitis,
• Apical periodontitis, periapical abscess abscess or cracks.
Negative response
• Healthy tooth
Sounds during percussion
• Dull note (abscess formation)
• Sharp note (inflammation)
• Metallic note (ankylosis)

6. Mobility and depressibility: The tooth is moved

buccally/lingually using handles of two instruments
(Fig. 9.5).
Two index fingers can be used, but effective only in
grade III mobility. To evaluate depressibility, apply
pressure apically on the occlusal or incisal aspects.
Mobility and depressibility evaluate the integrity of
the attachment apparatus. Fig. 9.5 Mobility and depressibility

Flowchart 9.1: Key features of percussion test

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 114 Essentials of Endodontics

Fig. 9.7 Tooth slooth placed in posterior region

b
Fig. 9.6a and b Periodontal probing

Orangewood stick, rubber wheel or tooth slooth is

placed on occlusal/incisal aspect of the tooth and
patient is asked to bite and then release the bite
(Fig. 9.7). If patient experiences sharp pain on release
rather than biting, it indicates a cracked tooth.
9. Test cavity
• A cavity is prepared deep into dentin without
anesthesia and without coolant (Fig. 9.8a and b)
• Pain/sensitivity during cavity preparation indicates
vital pulp a
• If pulp is reached without pain/sensitivity, proceed
with root canal treatment
• The cavity test is used as the last resort, being subjective.
10. Anesthesia test
• Anesthesia test is carried out when other tests have
failed
• Restricted to patients where pain could not be
localized
• Single tooth is anesthetized at a time
• Infiltration/intraligamentary injection is preferred
(0.2 ml anesthetic solution is deposited in distal

9 sulcus of the tooth)

• The process is carried out until pain disappears and
the tooth is localized.
b

Fig. 9.8a and b Test cavity

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 Diagnosis and Diagnostic Aids 115

11. Videography/intraoral camera: Miniature color

charged coupled devices (CCD) with fiberoptic probes
(video camera) are used to examine teeth and the
surrounding soft tissues in the oral cavity. The smaller
probes can be inserted into root canals to view root canal
intricacies. Images are captured and then displayed on
TV screen.

12. Fiberoptic transillumination: Fiberoptics (optical

fibers) refers to flexible, thin cylindrical fibers of high
quality glass/plastic (0.1 mm). Individual fibers are
grouped together to form fiberoptic bundles. Fiberoptic
transillumination works on the principle that caries,
calculus, restorative materials, sound tooth structure,
a
inflammatory exudates and healthy periodontium have
different indices of light transmission.
Since caries has a lower index of light transmission
than sound tooth structure, an area of decay and its
spread along the path of dentinal tubules will be
displayed as a dark shadow.
Periapical tissue may be similarly transilluminated;
teeth with a periapical pathology reveal a shadow
around the apex.
Fiberoptic transillumination is primarily used to:
• Detect cracks, discolorations, calcification in crown
(a calcified crown will appear more dull/opaque
than a tooth with a healthy pulp chamber).
• Aid in the determination of pulp vitality. In teeth b
with necrotic pulps, the shadow of the pulp chamber
Fig. 9.9a and b Transillumination
will appear darker.
• Detect caries, calculus and soft tissue lesions.
In clinical practice, the key areas of pulp testing are:
The fiberoptic probe should be held on the linguo-
i. Localization of pain: The origin of pain in tooth is
cervical area and an observation should be made by
mainly because of involvement of pulp. The pain
direct vision (Fig. 9.9a and b). If the probe is held on
is to be identified (testing pulp status), differen-
the labio-cervical area, then lingual surface should be
tiating from other non-odontogenic pains (normal
viewed with a mirror. During transillumination, the
response to pulp testing eliminates the diagnosis
main lights of the clinic and the dental unit should be
of pulp pathology).
switched off.
ii. Identifying radiolucent areas: Radiolucent areas at the
periapical region are generally indicative of pulp
PULP VITALITY TESTS pathology. If pulp response is normal, other
Pulp vitality testing is an important aid in the diagnosis reasons, such as periodontal abscess, cysts, etc. can
of pulp and periapical diseases (apical periodontitis). be considered. Normal anatomical structures, such
The ideal test should be accurate, reproducible and non- as mental foramen may also present as periapical
injurious. The commonly used tests are thermal and radiolucency.
electrical tests, indicative of the neural status of the iii. Preoperative assessment: Vitality tests are important
pulp; also called ‘Pulp Sensibility Tests’. to assess the pulp status prior to planning any
treatment for pulp/periapical pathology.
9
The pulp vitality tests, indicative of the blood supply
of pulp, are laser Doppler flowmetry, pulse oximetry, iv. Postoperative assessment: The teeth treated with pulp
etc. capping/pulpotomy procedures are periodically

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 116 Essentials of Endodontics

tested for pulp vitality. In case of no response, the In cases of advanced acute pulpitis, indicating
treatment is considered as ‘failed’, and other varying degrees of necrosis, cold may not exacerbate
treatment modality can be planned. the painful symptoms. If the peripheral coronal A-δ
v. Vitality testing is important in finalizing the fibers are not viable, they cannot be activated by fluid
treatment plan in traumatized teeth (traumatic teeth movement.
need to be assessed periodically). The cold may relieve symptoms of acute pain; the
vasoconstriction will reduce the blood volume thereby
The commonly employed tests are categorized as
reducing the high intrapulpal pressure.
follows.
Hot stimulation causes vasodilation and subsequent
increase in intrapulpal pressure. Intrapulpal pressure
A. Tests Assessing the Neural Status of Pulp rises when heat is applied to the tooth. In an intact pulp,
a. Thermal Test a specific pulpal temperature should be reached before
pain is felt.
Thermal tests are carried out to assess the status of the
In normal teeth, there is a delayed response to heat;
pulp. The patient’s response help to decide whether
whereas, in inflamed pulp, an increased intrapulpal
the pulp is healthy or inflamed; identifying the
pressure already exists. Therefore, the immediate
offending tooth when the patient is unable to locate
painful response to sudden/gradual heat is expected.
the source of the pain (results of thermal tests should
be correlated with other tests to ensure vitality). Thermal tests can be conducted as:
Advantages i. Cold test
• Easily performed The cold test (Fig. 9.10) helps:
• More reliable than electric pulp testing. • To differentiate between reversible and irreversible
pulpitis
Guidelines • To identify the necrosed teeth
Before commencing the thermal tests, follow the • If the pain subsides immediately after removing the
guidelines as: stimulus; suggestive of hypersensitivity or reversible
• Explain the implications of test to the patient. pulpitis
Demonstrate on a normal tooth. Explain the type of • Lingering pain (even after the stimulus is removed),
sensation, which patient may feel. suggests irreversible pulpitis.
• The site of performing the test is cervical-third of
the buccal surface of the posterior tooth and in Agents used in cold test
anterior teeth, center of middle and cervical-third of • Air blast
labial surface (thermal tests are not effective in posterior • Ice water bath
teeth; amount of dentin may act as insulator). • Ice stick
• The pain may be replicated by the tests; so be • Ethyl chloride spray (4°C), dichlorodifluoromethane (–21°C),
prepared to relieve the pain, if sets in. tetrafluoroethane (refrigerant spray) (–15°C to –26°C)
• There may be delayed response from few teeth. Wait • Carbon dioxide snow (dry ice) (–78°C)
for a minute before testing the next tooth.
• The response from crowned teeth will vary.
• Instruct patient on how to respond (e.g. raise your
finger when pain is felt).
• The concerned teeth should be isolated, dried with a
gauze or cotton (should not be dried with a blast of
air); salivary ejector is placed.
• The results should be recorded.
The response of thermal tests (heat and cold) is attri-
buted to different phenomena in pulp. The response to
cold stimulus is attributed to the hydrodynamic theory
(contraction of fluid in the dentinal tubules and the

9 subjacent pulpal tissues). Such a movement deforms

intratubular and peripheral (A-δ) nerves fibers, which
activates an action potential.
Fig. 9.10 Cold test—endo-ice (refrigerant spray: Tetra-
fluoroethane)

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 Diagnosis and Diagnostic Aids 117

The routinely used agents in cold test are: The routinely used agents in heat tests are:
 Ice stick: It should be applied at the junction of cervical  Hot burnisher/gutta-percha: The tooth is lubricated
and middle third of labial surface of tooth. Pencils with thin layer of cocoa butter/petroleum jelly. The
of ice can be made by filling discarded anesthetic tip of gutta-percha stick is heated for two seconds
carpules with water and kept in refrigerator. till it becomes shiny and placed at the junction of
cervical and middle third of labial surface (Fig. 9.11).
Disadvantages The test is convenient and easily manipulated.
• Cold water may drip onto the gingiva (false  Hot water technique: Isolate the tooth with rubber
positive) dam, pour hot water from a conventional syringe
for five seconds or until patient begins to feel
• Not as cold as other agents, viz. pain.
Ethyl chloride spray (4°C) dichlorodifluoromethane
Advantages
(–21°C) and tetrafluoroethane (refrigerant spray)
(–15°C to –26°C) • Simulates the existing conditions experienced by the
patient on taking hot food
The agent is sprayed on cotton pellet held in cotton • Effective in penetrating porcelain fused to metal
pliers and applied on tooth surface at the stipulated crowns
site. Spraying these agents directly on tooth surface  Heating devices and LASER: Heating devices, viz.
is not recommended. Gutta-percha cutters, system B and pulsed Nd:YAG
 Carbon dioxide snow (dry ice): Solid stick of carbon Laser are accepted alternative to hot gutta-percha
dioxide is prepared by delivering carbon dioxide gas method.
into a specially designed plastic cylinder. The carbon The pain produced is mild and tolerable.
dioxide stick (–78°C) is applied to the stipulated site
on the natural tooth or over the crown for five b. Electric Pulp Testing
seconds. The parts of electric pulp tester are: main device,
Disadvantages electrode probe tip and lip clip attachment (Fig. 9.12).
• May cause infarction lines on enamel, causing It is available either as battery operated or with
pitting even in five seconds.
• May damage the surface of ceramic restora-
tions.

ii. Heat test

Agents used in heat test (preferred temperature: 65°C)

• Hot water bath
• Hot air
• Hot burnisher
• Hot gutta-percha Fig. 9.11 Heat test with gutta-percha stick
• Hot impression compound
• Rubber wheel mounted on a mandrel
• Heating devices (system B – 150°F)
• LASER

Response to thermal test

• No response: Non-vital pulp or false negative
• Mild to moderate response, subsides within one to two seconds
after removal of stimulus: Healthy pulp
• Strong momentary painful response, subsides within one to
two seconds after removal of stimulus: Reversible pulpitis
• Moderate to painful response that lingers for several seconds
after removal of stimulus: Irreversible pulpitis
Fig. 9.12 Electric pulp tester
9

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 118 Essentials of Endodontics

• Inadequate contact with tooth surface (inadequate

conductor, composite restoration, large restoration
with bases)
• Recently traumatized teeth
• Young teeth with immature apices
• Older teeth with sclerotic dentin
• Excessive calcification in the canals
• No current (dead batteries).

Electric Pulp Testing Technique

Fig. 9.13 Electric pulp testing
Check the gadget prior to use
cords that plug into electric outlets; it stimulates
↓
response by electrical excitation of the neural elements
(Aδ fibers) within pulp. It does not provide any clue Coat electrode with good conductor gel
on the vascular supply of the tooth which is a real ↓
indicator of pulp vitality. Electric pulp testers are
Adjust lip clip attachment
difficult in teeth restored with full crowns and are
contraindicated in patients with cardiac pacemakers ↓
(Fig. 9.13). Adjust the rheostat to minimum current
(gradually increase the current during use)
Advantages
↓
• Electric stimulus is comfortable
• Digital display on electric pulp testers is instant, easy Ask the patient to indicate tingling sensation
and reliable (raising hand or any other sign)
• Provides a quantitative reading ↓
Start the procedure on control tooth
Disadvantages (antagonist or adjacent tooth)
• Cannot be used in patients with pace makers
↓
• False reading in immature teeth
Place the electrode tip at the junction of cervical and
• False negative response in recently traumatized
middle third of labial/buccal surface (less effective
teeth
in posterior teeth)
• No indication regarding vascular supply
↓
• Reading from multi-rooted teeth may be misleading
(partial necrosis). (Junction of middle and cervical third of anterior
teeth and the mesiobuccal cuspal tip on molar
False positive response (pulp is necrotic, but patient gives a teeth is the optimal site to determine
response) the lowest response threshold)
• Teeth involved in splints or bridges
↓
• Electrode contacting a large metal restoration
Gradually increase the current (up to 4.0 mA)
• Electrode contacting the gingiva
• Saliva acting as a conductor due to improper isolation ↓
• Patient’s anxiety Note the patient’s response
• Transfer of current to attachment apparatus due to ↓
liquefaction necrosis.
Take at least two readings and record the average
False negative response (pulp is vital, but no response from ↓
patient)
9 • Heavily pre-medicated patient (tranquilizers,
narcotics, etc.)
Do not repeat the stimulus for more than twice;
nerve tissue may react at a lower threshold

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 Diagnosis and Diagnostic Aids 119

Limitations of Pulp Sensibility

(Thermal and Electrical) Tests
• Tests remain inconclusive in children. Children do
not respond to a stimulus and the subjective
symptoms. Children avoid painful stimulus and their
ability to properly respond to pulp testing is limited.
• Thermal and electrical tests measure only nerve
responses and not the blood flow. a b
• Not effective in aged patients (reduced neural Fig. 9.14 Laser Doppler flowmetry: (a) Laser Doppler
component, reduced volume and deposition of flowmetry (clinical); (b) Laser Doppler flowmeter
secondary dentin making dentinal tubules narrow).
The response is weaker as compared to more carries light by one fiber and receives back the scattered
innervated and less calcified dentinal tubules in (reflected) light by another fiber to the instrument.
younger individuals. Fraction of light which is scattered back (Doppler
• Less reliable in immature teeth; also in teeth shift) is detected; output is proportional to the number
following traumatic injuries. and velocity of blood cells and produce a signal that is
• The response is different on different days, even at a function of the red cell flux (volume of cells
different hours of the same day (tests lack illuminated × mean cell velocity).
reproducibility). Color power Doppler flowmetry, a modified version,
• Extensive restorations, pulp calcification, pulp detects and elicits direction of blood flow within the
recession may create difficulty in interpreting pulp tissues (contrast media is injected to improve
status. observation). Power Doppler enhances the sensitivity
• The results of the tests may not correspond to the of the technique measuring blood flow.
histopathological studies.
Laser Doppler Flowmetry Technique
B. Tests Assessing the Blood Supply of Pulp
Place rubber dam to avoid interference of gingival tissues
The thermal and electric tests assess the response of
↓
Aδ nerve fibers in pulp-dentin complex. If Aδ nerve
Place fiberoptic probe on the tooth surface
fibers get stimulated, the patient responds as feeling
↓
pain/tingling from the tooth. A positive response
Project monochromatic laser beam on to
indicates functioning of Aδ fibers; however, no
the crown to the pulp
indication of blood flow in pulp tissues. In case of no
↓
blood flow, Aδ fibers cease to function; however, there
The reflected light in accordance with movement of
are instances, such as trauma, where there is blood flow
blood cells is received by the meter
in pulp, but A fibers are not functioning.
↓
Consequently, tests which measure blood flow are
Scattered light is processed producing output signal
considered ideal. Tests assessing the pulpal vascularity
↓
are:
Output signal can be displayed on digital board
a. Laser Doppler Flowmetry and/or printed
The laser Doppler flowmetry is a noninvasive technique Advantages
that detects red blood cell movement in a small volume
• Reflects vascularity of pulp
of tissue (about 10 mm3). It can measure blood flow in
• No problems with apprehensive patients
very small blood vessels of pulp; measuring micro-
circulation of pulp (Fig. 9.14a and b). • Noninvasive procedure
• Provides accurate reading in case of recently erupted
Principle teeth or traumatized teeth (effective in pulp testing
It utilizes light beam from a He-Ne laser (632.8 nm),
which is carried to the tissues by a fiberoptic probe that
of children)
• Effectively monitor revascularization of replanted teeth.
9

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Disadvantages Tooth is sandwiched between a photoelectric

• Systemic medications may alter blood flow in pulp; detector and an LED of red/infrared lights. It measures
subsequently, the readings oxygen pressure of erythrocytes (providing pulp
• Sensitivity to motion vitality), following two principles:
• Difficult to obtain laser reflection from certain teeth i. Light absorbance of oxygenated hemoglobin
(molar teeth with thicker enamel and dentin and is different from that of reduced hemoglobin, at
variability in the position of pulp within the tooth, the oximeter's two wavelengths, red and infrared
may cause variations in pulpal blood flow) light.
• Differences in sensor output and inadequate calibra- ii. The absorbance of both wavelengths has a pulsatile
tion by the manufacturer may dictate use of multiple component, which is due to the fluctuations in the
probes for accurate assessment volume of arterial blood between source and the
detector.
• Gingival blood vessels can give false readings
The relationship between the pulsatile change in the
• Need custom fabricated jig to hold sensor
absorption of red light and infrared light is assessed
• Equipment is expensive. by the oximeter to show the saturation of arterial
b. Pulse Oximetry blood.
Pulse oximetry determines the oxygen saturation of Advantages
circulating arterial blood. It analyzes changes in light • Effectively detects pulpal blood flow
transmission through any pulsating vascular area; the • Pulp circulation can be detected independent of
changes calculate pulse rate and the oxygen saturation. gingival circulation
As the hemoglobin is oxygenated, it increases
• Useful in traumatic injuries
transmission of light. Well-oxygenated blood appears
bright red. • Easy to reproduce pulp pulse reading.
The device consists of a probe containing two light Disadvantages
emitting diodes that emit light in two wavelengths; • Reliability—mixed results
(i) Red light (660 nm) and (ii) Infrared light (800 nm)
• Pulpal blood flow is not pulsed, as arterioles are
to measure the absorption of oxygenated and
present
deoxygenated blood respectively.
• Pulp is insulated by enamel and dentin, difficult to
The device may be ‘reflectance’ type or ‘transmission’
detect pulsations by the probe
type depending upon the type of light incident on the
detector (Fig. 9.15). • In addition to the absorption; refraction and
reflection also occur; some light reaches photo
detector diode without passing through the tissue
bed
• Only detect bound hemoglobin (hemoglobin bound
to other gases may give false results).

c. Dual Wavelength Spectrophotometry

Dual wavelength spectrophotometry measures
oxygenation changes in the capillary bed rather than
in the supply vessels. It does not depend on a pulsatile
blood flow. The presence of arterioles in pulp, coupled
with its covering by dentin, make it difficult to detect a
pulse in the pulp. However, various studies have
approved the efficacy of dual wavelength spectro-
photometry in pulp testing (Fig. 9.16).
Advantages
9 Fig. 9.15 Pulse oximetry
• Yield objective test results
• Instrument is small, portable and inexpensive

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 Diagnosis and Diagnostic Aids 121

a photoconductive cell with peak intensity for red and

infrared light to detect optical density changes. The
technique is used to detect circulating anomalies in the
human dental pulp. The components required are: a
light source to illuminate the tissue (tooth) and a photo-
detector to measure the changes, if any. A selected band
of light is passed through tooth, while continuously
monitoring the intensity of transmitted light. The
specific wavelength of light is absorbed by hemoglobin,
while the remaining light is passed through the tooth
Fig. 9.16 Dual wavelength spectrophotometry and is detected by the receptor.
• Uses visible light that is filtered and guided to tooth
by fiberoptics (eye protection not required as in laser RADIOGRAPHIC TECHNIQUES
light). Various radiographic techniques are employed to
diagnose pathological changes in teeth and the
d. Optical Reflection Vitalometer surrounding tissues (refer to Fundamentals of Dental
Optical reflection vitalometer (ORV) is based on the Radiology; 4th ed: Vimal K Sikri, for details of
same principle of pulse oximetry; uses reflected light radiographic techniques).
instead of transmitted light.
It measures oxygen in tissues by means of light, 1. Conventional Radiography
which is based on the fact that photons passing through Use of conventional radiography is vital for diagnosis
the human tissue are attenuated by absorption. Absorp- and follow-up in endodontics. It is a reliable source for
tion is spectrally sensitive especially infrared range gaining information regarding the pulp canal space and
where organometallic molecules such as hemoglobin the periapical tissues.
have characteristic absorption spectra that shifts with
oxygenation. Ideal Requirements of a Radiograph
• Image of tooth to be evaluated should be in centre
Difference between Optical Reflection Vitalometer (ORV) and of radiograph.
pulse oximetry; ORV uses reflected light instead of transmitted • Image should show 4.0–5.0 mm beyond the apex of
light as in Pulse oximetry the tooth and the surrounding bone or the pathologic
condition.
e. Photoplethysmography
• Should present an accurate image of the tooth; no
Photoplethysmograhy is a non-invasive method to elongation or fore-shortening.
detect vascularity (Fig. 9.17). It uses a light source and • Should exhibit good contrast, so that all pertinent
structures are readily identifiable?
• In multi-rooted teeth with curved canals, at least two
radiographs should be taken; one at a normal vertical
and horizontal angulations and other with a 20°
horizontal angulations, either in mesial or distal
direction.

How to ‘Read’ a Radiograph

Proper illumination and magnification gadgets (X-ray
viewer with magnification lens) are essential for reading
a radiograph. A radiograph should be thoroughly
evaluated from one corner to the other.
The radiographs provide information as:
i. Integrity of the crown and the roots

Fig. 9.17 Photoplethysmography

• Proximal caries, secondary caries, root caries
• Number of roots/extra roots
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 122 Essentials of Endodontics

• External resorption Mesial/distal angulations further reveal:

• Crown/root fracture. • Number of roots
• Number of root canals
ii. Internal anatomy of the tooth
• Presence of buccal/lingual canal curvature
• Size of the pulp chamber and its proximity to the
• Differentiate the true dental lesions from the false
restoration/caries
ones.
• Depth of the restoration: pulp capping, pulpotomy
(remaining dentin over pulp) The techniques used in conventional radiography are:
• Pulp stones a. Paralleling cone technique/long cone technique:
• Dystrophic calcifications X-ray film is supported parallel to long axis of the teeth
• Internal resorption and central ray of the X-ray beam is directed at right
• Blunderbuss canals angles to the teeth and film. Placing X-ray film parallel
to long-axis in maxillary posterior teeth is difficult; a
• Root canal system
cotton pellet is placed in between film and the tooth to
– Length of the root make the technique semi-parallel. This modified
– Mesiodistal width of the pulp canal space paralleling technique is preferred in maxillary molars
– Position of canal (s) (Fig. 9.18a and b).
– Mesial/distal curvature of the root
Advantages
– Hint towards position of the apical foramen
i. Dimensional accuracy
– Apical radiolucency
• Minimal distortion
– Lateral radiolucency (indicating lateral canals)
• No superimposition of shadow of zygomatic arch
– Physiological radiolucency (mental foramen, etc.)
on maxillary molars
• Periodontal defects.
• Teeth apices and maxillary sinus better visualized
iii. Integrity of the lamina dura: The lamina dura is a
thin white line seen around the root with the radio- • Length of teeth can be easily measured.
lucent periodontal ligament in between. It is the thin ii. Simplicity: Beam alignment device eliminates the need
cortical bone into which the periodontal fibers are for dental radiographer to determine horizontal and
embedded. vertical angulation.
The strain on the teeth or expansion of pulpal
disease can be observed as a thickening of the lamina
dura.
There may be break in continuity of lamina dura,
which indicates spread of the disease with visible
breach in the cortical bone plate.
iv. Trabecular pattern of bone and the surrounding
structures: It is important to be familiar with normal
bone trabecular pattern; to be able to identify the
changes which may occur due to diseases. a
The height and pattern of alveolar crest, the appea-
rance of normal radiographic features and other regular
findings will help in identifying the abnormal findings.

Buccal Object/SLOB/Clark’s Rule

This rule is based on the principle that, the root or canal
farthest from the film (buccal) moves the greatest
distance on a radiograph taken with the cone angled in
the horizontal plane. If the cone is pointed from the
mesial aspect toward the distal when a bi-canaled b

9 bicuspid is radiographed, the buccal root image will

move more than lingual and appear distal to the lingual
root image on the film.
Fig. 9.18 (a) Radiograph of maxillary molar by bisecting
technique; (b) Radiograph of same tooth by modified
paralleling technique

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 Diagnosis and Diagnostic Aids 123

iii. Duplication: Easy to standardise; can be accurately image of the crown and the alveolar crest. The technique
duplicated when serial radiographs are indicated. is useful for diagnosing proximal caries and morpho-
logy of coronal pulp (Fig. 9.20).
Disadvantages
• Difficulty in film placement in child patient and also Limitations of conventional radiography
in adult patient with a small mouth opening or • Two-dimensional image of three-dimensional object
shallow palate. • State of pulpal health cannot be ascertained
• Discomfort (film holding device may impinge on oral • Periapical pathology can be evident only after 33%
tissues) of bone destruction
• Expensive. • Vertical root fractures cannot be diagnosed
• Anatomic structures can mimic radiolucency
b. Bisecting technique/short cone technique: The • Extent of caries or periapical pathology is much
central ray is directed perpendicular to the bisector larger than what is seen on the radiographs
of the angle between film and the tooth (Fig. 9.19a
• Bony trabeculae can be misinterpreted for horizontal
to d).
root fractures.
Advantage Sinus tracing: The presence of long-standing chronic
• Can be used in patients with shallow palate, bony periradicular diseases may lead to sinus formation with
growths. opening in the vestibule. It is essential to locate the
Disadvantages origin of the sinus tract (the offending tooth) so
that proper treatment can be carried out. In this
• Image distortion
technique, gutta-percha point is inserted through the
• Difficulty in determining the angulation: any error
sinus tract opening till it moves towards the lesion,
in vertical angulations lead to image distortion.
followed by intraoral radiograph to determine the exact
• Unnecessary exposure of the patient’s hand to X-rays. point of origin of the lesion (Fig. 9.21). Sinus tracing
c. Bitewing technique: Bitewing radiographs are used helps:
to evaluate mainly the changes in the coronal tooth • To localize endodontic lesion to a specific tooth
structure. The cone, kept parallel to the film, provides • To differentiate endodontic from periodontal lesions.

a c

9
b d

Fig. 9.19 Bisecting technique: (a) Radiograph of maxillary molars; (b) Diagnostic radiograph of maxillary first molar;
(c) Radiograph of mandibular molar; (d) Obturated mandibular molar

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 124 Essentials of Endodontics

2. Radiovisiography (RVG)
Radiovisiography digitizes ionizing radiation that
provides instant image on a video monitor. The
technique reduces radiation exposure by 80%.

It has three components:

• Radio: Consists of a hypersensitive intraoral sensor and
an X-ray unit
• Visio: Video monitor and display processing unit
Fig. 9.20 Bite wing radiograph (arrow showing caries) • Graphy: High resolution video printer.

Two kinds of detectors are used in radiovisiography:

• Charged coupled device (CCD)
• Photo-stimulable phosphor (PSP).
Image is captured directly on charged couple device
(CCD) placed in a patient’s oral cavity.
Signal from the CCD computer is digitized into 256
gray levels, displaying the image on monitor; enhanced
by varying contrast (Fig. 9.22).

Advantages
• Elimination of X-ray film and processing errors
• Decreased radiation exposure (up to 80% less)
• Manipulation of image as varying contrast is possible
• Image can be duplicated and stored in a computer
Fig. 9.21 Sinus tracing in maxillary first molar • Lesser time for images.

9 Fig. 9.22 Radiovisiography image and their modified forms

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 Diagnosis and Diagnostic Aids 125

Disadvantages
• High cost
• Size of the sensor
• Low doses can impair image quality
• Inability to sterilize the sensor
• Manipulation of data possible
• Incompatibility with some existing X-ray machines.
3. Xeroradiography
Xeroradiography involves the production of a visible
image utilizing a charged surface of a photoconductor
as the detecting medium (selenium applied to sheet of
aluminium known as xerographic plate); partially
dissipating the charge by exposure to X-rays (25
seconds) to form a latent image and making the latent a
image visible by xerographic processing.
It is a complex electrostatic process and needs a
photoconductor.
Advantages
• High contrast
• Edge enhancement
• Greater ability to resolve fine structure
• Choice of positive and negative display
• Display fine details of bone and teeth.
Disadvantage
• High chances of artefacts.
4. Digital Subtraction Radiography
Digital subtraction radiography depicts diagnostic b
information without background noise (those struc-
tures with no diagnostic importance). It is performed
by subtracting the gray level values of one radiograph
from the corresponding gray levels of another radio-
graph; what remains after subtraction is an image of
the differences between the two images (Fig. 9.23 a to c).
The technique is mainly used for reviewing the
progress of caries and periapical lesions.
Advantages
• Ability to remove structured noise
• Detection of changes
• Reduces sources of error
• Can detect loss of cancellous bone
• Helps in monitoring bone healing c
• Evaluation of internal and external resorption
Fig. 9.23a to c Digital subtraction radiography: (a) Pre-
• Evaluation of periapical scars. operative radiograph before periodontal surgery showing
Disadvantages bone loss mesial to first molar; (b) Postoperative radiograph
after periodontal surgery (four months) showing bone
• No geographic reproducibility of X-ray source-to-
object relationship (intraoral stent to X-ray source)
• Expensive.
mineralization mesial to first molar; (c) Digitally subtracted
radiograph showing detailed areas of bone mineralization
(white areas—arrows)
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 126 Essentials of Endodontics

(In digital subtraction radiography, it is difficult to Micro Computed Tomography

improve sensitivity or speed of detecting periapical changes. In micro computed tomography (Micro CT), X-radiations
The densitometry assessment of separate radiograph, where are converged over the sample and captured by a
the gray value measurements are used to provide numerical sensor. The projected rays are converted to digital
data on the progress/healing of apical lesions). images. The volumetric pixel (voxel) provided by
micro CT ranges between 5 and 50 μm. Micro CT allows
5. Computed Tomography (CT) the use of same sample for different tests without
Computed tomography (CT) provides three- destruction of sample; however, it permits the
dimensional image of an object. CT images have the examination of specimens of limited size, limited to in
ability to evaluate the target tissue in thin slices vitro specimens.
(1.0–2.0 mm thick). The location of the slides can be The technique is useful for in vitro analysis of internal
predetermined by the operator. Earlier CT scanners anatomy of teeth, root canal instrumentation, retreat-
utilized single detector to capture X-ray beams. Later, ment of failed root canals, etc. (preferred in preclinical
more than one detector were popularized with arc- training of students for learning endodontic procedures).
shaped and circular detectors. Current CT scanners use
Spiral Computed Tomography
multiple (64) detectors, which simultaneously detect
images. Computed tomography detects mesiodistal as Spiral computed tomography acquires projection data
with a spiral sampling three dimensional reconstruc-
well as labiolingual extent of the pathology. In
tion. This technique is useful to reconstruct overlapping
endodontics, it is useful in diagnosing number of canals,
structure at arbitrary intervals, increasing the ability
morphological abnormalities, calcification of root canal,
to resolve small objects.
three-dimensional image of root canal, such as root
The technique is used in endodontic applications,
curvature and diameter of root canal (Fig. 9.24a and b).
such as evaluation of root fracture, analysis of root
Advantages resorption, location of extra/aberrant root canals and
other pulp space anomalies.
• Detects three-dimensional image of root canals
• Reveals thickness of the cortical bone Tuned-aperture Computed Tomography (TACT)
• Eliminates anatomical noise. Tuned-aperture computed tomography (TACT) is
advantageous because the images produced have
Disadvantages less anatomical noise and absence of artefacts.
• Radiation dose is high The technique has been utilized to detect vertical
fractures and also aberrations in root canal anatomy;
• Geometric resolution is inadequate however, TACT is rarely used for endodontic
• Expensive. applications.

9 a b
Fig. 9.24a and b Computed tomography (CT) scanners

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 Diagnosis and Diagnostic Aids 127

6. Magnetic Resonance Imaging (MRI) images at a low cost and least radiation exposure. It
Magnetic resonance imaging (MRI) is a noninvasive utilizes a cone beam instead of a fan-shaped beam of
conventional CT, acquiring images of the volume as
imaging technique, which uses radio waves in spite of
desired. Limited volume CBCT scanners can capture
ionizing radiations. MRI is best suited in evaluating soft
40 mm × 40 mm volume of the data (data acquired is
tissues; whereas, it does not provide good details of captured in term of ‘volume’, which is made up of
bony structures. voxels (3D pixels)). The technique elicits a high
In endodontics, MRI is effective in differentiating spatial resolution of bone and teeth along with adjacent
small branches of neurovascular bundle entering apical tissues.
foramen. It also evaluates periapical lesions as well as The limited volume CBCT machines are most appro-
thickening of cortical bone. MRI scans are not affected priate for examining individual teeth for fracture/peri-
by artefacts caused by metallic restorations, contrary apical disease/endodontic applications and are
to the CT technology. preferred over large volume CBCT for the following
reasons:
Advantages • Provides objective and accurate representation of
• No ionizing radiation involved osseous changes overtime.
• Direct multiplane image is possible without re- • Increased spatial resolution to improve the accuracy
orienting the patient of endodontic-specific tasks like visualization of
• Resolution of soft tissues is good accessory canals and root fractures.
• Safe in pregnant ladies and infants • Least radiation exposure to the patient.
• Image can be manipulated. • Time saving.
Disadvantages Limitations of CBCT
• Imaging time is long • CBCT images lack resolution of conventional radio-
• Metal present in the vicinity of the imaging magnet graphs
can be hazardous • Metal crowns and posts affect the image quality and
• Contraindicated in patients with pace makers diagnostic efficacy
• Expensive. • Presence of artefacts
A recently developed MRI method, SWIFT (sweep • Radiation dose is higher than conventional radio-
imaging with Fourier transformation), overcomes many graphic level.
difficulties of detecting fast relaxing signals. The
technique offers three-dimensional analysis of hard and Utility of CBCT in Endodontics
soft tissues without subjecting the patients to ionizing a. Hidden periapical lesion: The clinical and radio-
radiations. graphic assessment, many a times remain inconclusive
to differentiate the offending tooth (Fig. 9. 26). Limited
7. Cone Beam Computed Tomography (CBCT)
Cone Beam Computed Tomography (CBCT) serves as
a bridge from 2D to 3D with lower irradiation than
computed tomography (Fig. 9.25). CBCT produces 3D

9
a b

Fig. 9.25a and b Cone beam computed tomography Fig. 9.26 Periapical radiograph not showing any periapical
(CBCT) pathosis

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 128 Essentials of Endodontics

Fig. 9.27 CBCT showing periapical radiolucency (maxillary

canine)

Fig. 9.29: No pathology in conventional CT

Fig. 9.28 Root canal treated maxillary canine

volume CBCT clearly showed a lesion at the apex of Fig. 9.30 No pathology in periapical radiograph
upper left canine (Fig. 9. 27). The length of the tooth
was accurately measured using the CBCT, thus
allowing precise placement of the root canal filling
material (Fig. 9.28).
b. Sinus infection secondary to periapical infection:
The conventional CT scan could not reveal definite
pathological lesion (Fig. 9.29). The periapical radio-
graph of the region also did not clearly show any
pathosis (Fig. 9.30 ). Cone beam CT scan of the region
(Fig. 9.31) showed a periapical lesion at the apex of
upper first molar. The lesion had perforated the floor
of the maxillary sinus suggesting that the maxillary
sinus infection was secondary to an infected pulp and
periapical abscess associated with upper left first molar. Fig. 9.31 CBCT showing perforation in maxillary sinus
Endodontic treatment was carried out on the tooth. This
illustrates an intimate relationship between maxillary
posterior teeth and the maxillary sinus.
c. Hidden lesion and missed canals: The periapical radio-
graph shows a radiolucent periapical lesion in endo-
dontically treated upper first molar (Fig. 9.32a and b).

9
Limited volume CBCT revealed a missed fourth a b
canal in the mesial buccal root of upper first molar Fig. 9.32 (a) Preoperative (maxillary first molar); (b) Root
(Fig. 9.33) and also radiolucent lesion and four canals canal treated (maxillary first molar)

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 Diagnosis and Diagnostic Aids 129

Fig. 9. 33 CBCT showing missed fourth canal

Fig. 9.36a Extra canal treated
associated with roots of upper right second molar.
CBCT is useful to locate hidden periapical lesions
and also to determine the number of roots and root
canals.
The periapical radiograph did not reveal extra root
canal in mandibular first molar (Fig. 9.34). Limited field
view CBCT revealed that mandibular first molar had
five canals and an additional canal (distolingual) was
missed (Fig. 9.35). The tooth was accordingly retreated
(Fig. 9.36a and b).
d. Additional roots: The periapical radiograph of
maxillary left lateral incisor shows a diffuse radio-
lucency in the cervical region of upper left lateral
incisor, which was endodontically treated (Fig. 9.37a Fig. 9.36b Tooth retreated
and b). CBCT axial, reformatted panoramic and cross-
sectional images showed a second untreated missed
root, mesial and buccal to the treated root (Fig. 9.38a
and b ). When the second root was treated and filled,
the tooth healed uneventfully (Fig. 9.39).

a b

Fig. 9.37 Maxillary lateral incisor: (a) Preoperative; (b) Root

canal treated

e. Dehiscence: The periapical radiograph of maxillary

molar does not show any definite finding (Fig. 9.40);
whereas, CBCT coronal slices (Fig. 9.41) revealed that
Fig. 9.34 Preoperative the apices of the buccal roots were outside the buccal
cortical plate of bone. Apicoectomy was performed on
both the roots (Fig. 9.42) and the patient was relieved
of symptoms.

Fig. 9.35 CBCT showing extra canal

f. Planning endodontic surgery: The periapical
radiograph shows proximity of the apices of first and
second molars to the mandibular canal (Fig. 9.43). CBCT
9

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 130 Essentials of Endodontics

Fig. 9.41 CBCT showing roots outside buccal cortical plate

Fig. 9.38a and b CBCT showing extra canal in lateral incisor

Fig. 9.42 Tooth after apicoectomy

Fig. 9.39 Treated tooth

Fig. 9.43 Proximity to mandibular canal

Fig. 9.40 No definite finding in maxillary molar

imaging (cross-sectional view) shows widening of
periodontal ligament at the apex of distal root of second

9 molar and its close proximity to the mandibular canal

(Fig. 9.44). Apical surgery could be risky, so extraction
was planned.
Fig. 9.44 CBCT confirming close proximity to mandibular
canal

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 Diagnosis and Diagnostic Aids 131

g. Evaluating vertical fracture: The periapical radio-

graph of lower left first molar (Fig. 9.45) failed to show
any pathosis; whereas, CBCT (cross-section view) of
the region showed the loss of bone all along the distal
surface of the mesial root of mandibular left first molar
consistent with vertical root fracture (Fig. 9.46). This case
clearly illustrates the value of CBCT when compared
to 2D intraoral periapical radiography for detecting
bone loss secondary to vertical root fracture.
h. Cervical root resorption: The periapical radiographs
of the tooth shows a diffuse area of radiolucency in the
cervical region of the tooth (Fig. 9.47). CBCT images
(cross-section view) shows areas of resorption both on
the facial and the lingual surfaces (Fig. 9.48). The lesion Fig. 9.47 Diffuse radiolucency in cervical areas of maxillary
on the lingual aspect of the tooth was not detected canine and first premolar
clinically and its location could not be predicted from
the periapical radiograph.
i. Internal root resorption: The periapical radiograph
of lower first molar revealed an area of decreased
density in the coronal region (Fig. 9.49). CBCT images
(cross-section view) revealed a large resorptive
defect which had perforated the lingual aspect of the
tooth below the crest of bone (Fig. 9.50). The different

Fig. 9.48 CBCT (cross-section view) showing resorption

Fig. 9.45 Mandibular first molar (no pathological finding)

Fig. 9.49 Decreased density in coronal region of

mandibular first molar

Fig. 9.46: CBCT (cross-section view) showing vertical root

fracture Fig. 9.50 CBCT (cross-section view) revealing resorption
9

t.me/Dr_Mouayyad_AlbtousH
 132 Essentials of Endodontics

slices reveal the extent and location of the defect provide high positioning flexibility and excellent
which could not be determined by the periapical radio- patient access.
graph. C-arm imaging systems with automated exposure
control adjust X-ray exposure parameters, such as
8. C-Arm Imaging detector entrance dose (detector entrance dose is the
C-arm imaging is a new, dynamic, innovative and X-ray dose measured behind the antiscatter grid; whereas,
moving real time imaging technique, that differs from system dose is the detector entrance dose evaluated at a
conventional dental radiography which is static. reference detector zoom format). The detector entrance
Clinicians can observe live imaging event, while in dose for C-arm imaging is about half the system
previous imaging techniques, the operator could dose.
monitor treatment progress by making radiographs C-arm 3D real time imaging is helpful in routine
before and after the procedure. C-arm imaging system treatments, especially in aberrant canal anatomy. The
in endodontic practice provides a cutting edge over technique is also useful in by-passing the separated
existing methods because of its advantage of real time instruments and instrument (post) retrieval during
imaging. retreatment procedures. Procedural errors are also
C-arm cone beam computed tomography (CT) is an effectively managed by this system (Fig. 9.51a to d).
advanced imaging technique that uses C-arm flat-panel
fluoroscopy systems to acquire and display three-
dimensional (3D) images. It provides high and low
contrast soft tissues (CT-like) images in multiple
viewing planes.
Images intensifying principles have considerably
reduced harmful effects of radiations. An image
intensifier, also provides real-time imaging, facilitating
position of the patient and to visualize pathology of
interest. To keep the radiation dose from becoming a
health hazard, the exposure rate in C-arm CT image a c

intensification is much less than in conventional radio-

graphy. As per the manufacturers, the maximum
radiation dose for the present system used is 0.25 mSv
for 5 second exposure time.
In case of analog image intensifiers, the X-ray strikes
a fluorescent surface after being attenuated to different
degrees through the patient body. Depending upon the
strength of radiation, the surface can glow more or less
bright. A vacuum tube captures the glow and displays b d
this on the monitor. Due to curved surface of the tube,
Fig. 9.51 C-arm imaging: (a) Preoperative (mandibular first
the accuracy of image diminishes towards the edges,
molar); (b) Negotiating separated instr ument; (c)
leading to distortions. Endosonic file widening the dentin around separated
The modern flat-panel technology is the digital instrument; (d) Postobturation
development of image intensifier technology. The
intensity of the incoming X-rays is converted directly TESTS MEASURING TOOTH TEMPERATURE
into a digital value. Dispensing with electron optics
The temperature measurement of teeth provides
allows distortion free images, hence improving the
valuable information of the integrity of the underlying
overall image quality.
pulp. The underlying principle is that the teeth with
C-arm imaging (capturing 3D images) comprises a vital pulps (effective blood flow) are warmer as
stand and a C-arm to which the detector, X-ray tube compared to nonvital teeth (no blood flow). A few

9 and collimator are attached. The C-arm keeps the

X-ray tube, collimator, and a flat-panel detector exactly
aligned under varying view angles. C-arm systems
authors (Fenibunda, 1986) reported that there was
no difference in the surface temperature of vital and
non-vital teeth. He opined that the effect of blood supply

t.me/Dr_Mouayyad_AlbtousH
 Diagnosis and Diagnostic Aids 133

in a tooth is masked by the environmental factors. He

further stressed that the time taken to reach equilibrium
(rate of return of surface temperature to normal after
the application of thermal change) depended upon the
pulp blood supply. The gadgets used in measuring
surface temperature are thermocouple, thermistor,
infrared thermometer and cholesteric liquid crystals.

1. Cholesteric Liquid Crystals

Howell et al (1970) employed color change of cholesteric
liquid crystals applied to surfaces of the teeth as
diagnostic modality (Table 9. 2 ). Crystalline cholesteric
crystals (cholesteric compounds in 10% solution in
Fig. 9.52 Electronic thermography
chlorinated hydrocarbon solvent) heated to its melting
point become cloudy liquid, exhibiting crystal like
NEWER METHODS
properties under polarized light. Changes in tempera-
ture alter the pitch and period of helical structure; 1. Ultrasonic Imaging
subsequently new colors are produced. Ultrasound imaging or ultrasonography is being tried
The major advantages of cholesteric liquid crystal in endodontics to overcome the limitations of computed
technique include simplicity of use. It is hypothesized tomography (high cost and greater dose of radiations).
that vital pulp even in apical third area can maintain It is based on the reflection of sound waves (the interface
the surface temperature of tooth. This technique is no of tissues have different acoustic properties); the
longer advocated now. frequency is above the range of human hearing
(1–20 kHz). The echoes are converted into electrical
2. Electronic Thermography signal by the transducer, producing white and gray
The components of electronic thermography are shades on the screen. Hard tissues (bone and teeth)
infrared sensor, control unit, thermal image computer, produce high echo intensity (hyperechoic) and are
software, color monitor and printer (Fig. 9. 52). It is used white; whereas, soft tissues, which do not reflect
to check pulp vitality by electronically measuring the ultrasound energy (anechoic) are dark in reflection.
change in temperature onto the tooth surface. • Low echo signal: Dark spots
• High echo signal: Bright/white spots.
3. Infrared thermography (Hughes Probeye Camera)
Infrared thermography can detect temperature changes • Hypoechoic/transonic: Low echo intensity
as small as 0.1°C, measuring the pulp vitality. It consists • Anechoic: No reflection of echoes (occurs in any area filled
of thermal video system and the silicon close-up lens. with fluid)
• Hyperechoic: High echo intensity (bone)
The disadvantages of surface temperature measure-
ment technique are that the patient should be at rest
Ultrasound imaging is considered as a safe method,
and get acclimatized prior to testing. Proper isolation but the ultrasound energy which produces heat in
is also necessary. the tissue should be controlled. This limitation is quite
less as compared to techniques using ionizing radiations.
In endodontics, the technique can be useful in
Color changes and pulp vitality status using evaluating periapical lesions and also the vascular
Table 9.2
cholesteric liquid crystals
supply of these lesions; however, lesions covered by
Color change Vitality status cortical plates are difficult to evaluate.
Blue-green
Green-blue Vital Ultrasound imaging differentiates between cyst and
Red-green granulomas; reveals nature of bony lesion content:
Green Vital • Cystic lesion: Hypoechoic, well contoured cavity surrounded
by bony walls, filled with fluids (do not exhibit vascular supply

9
Red in color Doppler examination)
Yellow-red Nonvital • Granulomas: Poorly defined lesion, can be hypo or hyper-
Yellow echoic (exhibit vascular supply in color Doppler examination)

t.me/Dr_Mouayyad_AlbtousH
 134 Essentials of Endodontics

Advantages 2. Computer Expert System (COMENDEX)

• Accurately identify the underlying disease process In computer expert system, diagnostic case facts are
• No harmful effects of ultrasound waves entered into the computer and then computer analyzes
and report the diagnosis.
• Does not produce superimposition of structures. It helps in diagnosis of selected pulp pathology (rever-
Disadvantages sible pulpitis, irreversible pulpitis, and necrotic pulp).
• Ultrasound image cannot evaluate periapical lesion 3. LASER Optical Disc Storage
unless there is discontinuity in the buccal cortical Laser optical disc storage has superior diagnostic
bone advantage. It can store 10,000 images on 8 inches optical
• Provides two-dimensional picture; however, disc with 0.5 seconds retrieval and display time. Image
certain software may convert the image to three- is recorded by a focused LASER beam, heating a thin
dimensions. film of tellurium suboxide at specific points on the
• Not feasible in posterior region because of thick optical disc.
cortical plate (thick cortical plate prevents ultrasound The clinical usage and limitations of various diagnostic
waves from traversing in those areas). tools used in endodontics are summarized in Table 9.3.

Table 9.3 Clinical usage and limitations of diagnostic tools in Endodontics

Diagnostic technique Clinical usage Limitations
Thermal tests • Assess vitality of pulp (neural based) • Assess only neural aspects and not
• Help in identifying the offending tooth when patient is blood supply
unable to locate the source of pain • Difficult in posterior teeth
• Difficult in crowned teeth
Electrical tests • Assess vitality of pulp (neural based) • No clue of vascular supply
• Electric stimulus is considered comfortable as compared • Difficult in teeth restored with full crowns
to thermal and even in normal posterior teeth
Pulse oximetry • Determines oxygen saturation of pulp blood • Blood in arteries is not pulsed; may not
• Effectively detects pulp blood flow even in traumatized be effective
teeth • Some refracted light may give false
response
Laser Doppler • Detects red blood cell movement even in smaller tissues • Systemic medication affect blood
flowmetry • Effectively measures microcirculation of pulp flow in pulp; may give false response
• Different sensors may need multiple
probes for accurate assessment
Computed • The clinical usage include excellent visualization of • High radiation dose
tomography (CT) maxillary sinus and adjacent teeth • Expensive software
• Evaluate periodontal ligament vis-à-vis periodontitis • Low resolution of image
• Detects vertical root fractures or split teeth (periapical • Metallic crowns/posts affect quality of
radiographs can rarely detect such lesion) image
• Can be used to localize foreign bodies in the jaws
Cone beam computed • Diagnosis of endodontic lesions • Artifact formation
tomography (CBCT) • Assessment of the non-endodontic lesions and hidden • Less resolution
lesions, evaluation of root fractures and trauma • Metal crowns/post affect image quality
• Analysis of external, internal root resorption
• Analysis of cracks, dehiscence, etc.
Magnetic resonance • Smaller branches of the neurovascular bundle can be • Poor resolutions as compared to
imaging (MRI) identified entering apical foramina conventional radiographs
• Assess the nature of endodontic lesions before and after • Long scanning times
periapical surgery
Ultrasound imaging • Detects soft tissue lesions (assess lesion before and after
surgery)
• Differentiates between cyst and granuloma (reveals nature Difficult to use in the posterior region

9
of bony lesion contents) because of thick cortical plate (thick
plate prevents ultrasound waves from
traversing on that area)

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 Diagnosis and Diagnostic Aids 135

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t.me/Dr_Mouayyad_AlbtousH
Chapter
10
Endodontic Case Selection:
Treatment Planning
Case selection and treatment plan are important aspects extraction and implant as replacement. Till date, there
of endodontic treatment. The treatment plan is based is no definite documentation comparing endodontic
upon the knowledge and skill of the operator coupled therapy with single-tooth implant. Both are predictable
with patient’s preference. Each case is to be treated as procedures when treatment is appropriately planned
‘individual’, since there is no definite principle, which and executed.
can be applicable to every patient. It is emphasized that every effort is to be made to
Once appropriate diagnostic tests have confirmed the retain the natural tooth and the implant is planned only
pulpal and/or periradicular lesion, immediate if the root canal is contraindicated or the prognosis is
treatment should be directed towards relieving the questionable.
pain. After the emergency treatment, the operator
The teeth with reasonable coronal structure and
should decide as regard the prognosis of the concerned
adequate root with sufficient surrounding alveolar bone
tooth. Two important questions the operator must ask
are considered appropriate candidate for root canal
himself/herself are (i) whether root canal treatment is
treatment. The outcome of primary root canal therapy
the best suited approach as compared to implant
depends upon the conditions, such as, absence of peri-
placement and (ii) whether the operator is competent
apical radiolucency, root obturated three-dimensionally
enough to manage the case or some ‘specialist’ is to be
within the working length and also satisfactory coronal
called or the patient be referred to the skilled operator.
restoration. Various studies have confirmed that
The increasing number of dental surgeons are now
primary endodontic treatment was more successful in
opting for extraction and implant placement rather than
teeth without apical periodontitis than in teeth with
root canal treatment and postendodontic restorations.
apical periodontitis. Even teeth that have failed initial
High commercial gains might be one of the reasons for
endodontic treatment can be successfully retreated
the same; or root canal treatment being technique
using non-surgical/surgical procedures. Re-treatment
sensitive and time consuming, might not be as viable
has also been successful as long-term treatment
as implants.
outcomes. The major technological and biological
Efficiency, profitability and also patient’s satisfaction advances have resulted in the development of new
are the results of well-planned procedures. Endodontic treatment modalities in both surgical and non-surgical
treatment results are a by-product of the clinicians’ endodontics. Over the year, the success rate in
knowledge, planning and execution of the procedures. endodontic treatment has improved.
It is essential to consider patient’s needs, attitude and
willingness to undergo the specific treatment regime. In osseointegrated implants, sufficient quantity and
The patient’s general health and the medical conditions quality of bone, free from any disease, should be
should also be taken into account during planning a available for implant placement. It is important to
case for endodontic procedure. evaluate the location of vital anatomical structures that
can interfere with implant placement (inferior alveolar
canal, mental foramen, maxillary sinus, etc.). Immediate
ENDODONTIC TREATMENT VS placement of implants offers advantages over delayed
OSSEOINTEGRATED IMPLANTS placement techniques. The advantages include
It is always challenging to decide whether to pursue preservation of existing bone and maintenance of the
endodontics (especially for a complicated tooth) or gingival form and contours.

138

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 Endodontic Case Selection: Treatment Planning 139

In certain situations, implants are considered better Flowchart 10.1: Endodontic treatment vs osseointegrated
therapeutic alternative than compromised restorations. implant: Decision-making
A large number of factors, which facilitate the clinician
to take right decision are mandatory to be considered
in the beginning.
The factors are:
• Patient’s need and expectations, finances, esthetics
and also the patient’s compliance
• Severity of periodontal conditions; pocket depth,
tooth mobility and bone loss, etc.
• Furcation involvement; severity of furcation defects,
anomalies of root and root canals, etc.
• Treatment factors; unfavorable crown-root ratio,
faulty restorations, fractures, lack of remaining tooth
structure, etc.
• Systemic diseases affecting the healing process;
radiation therapy, Parkinson’s disease, multiple
myeloma, etc.
It is also emphasized that implants resist dental caries,
periodontal diseases and are able to restore structural
deficiencies. Endodontic therapy with adequate restora-
tion present better way to preserve function as compared
to implants, which can be placed only where prognosis
of endodontic treatment is poor. Another advantage of
endodontic therapy is early restoration of the patient’s
function and esthetics (in implants, restoration may be
delayed while waiting for bone integration).
Before deciding for extraction, possibility of ‘dental
implant’ should also be considered, which can be a
predictable alternative procedure depending upon the
condition of the concerned tooth and the patient’s
systemic health. All options should be considered on
the basis of sound biologic principles and finalized
on case to case basis.
The decision-making as regard endodontic treatment
or osseointegrated implants is depicted in Flowchart 10.1.
The choice of postendodontic restoration may also
CASE SELECTION (TREATMENT PLANNING) influence the outcome of endodontic treatment. The
IN ENDODONTICS restoration should provide adequate coverage to
Many root canals are treated today than before because reinforce and protect the endodontically treated tooth.
of a greater interest of operators to save endodontically Improper restoration may allow microorganisms to
involved teeth, which can be restored as a single unit invade the filled root canal spaces. It has been
and/or can be used as abutments for fixed prosthesis. established that both root canal filling and the coronal
The treatment plan remains simple if only one tooth is restoration serve as a barrier against fluid and bacterial
involved and the status of rest of the dentition is accept- penetration into the periapical area. A number of
able. It is mandatory to provide symptomatic relief of studies have shown that inadequate root canal filing
the pain and swelling prior to root canal treatment. and coronal restorations were associated with an
The remaining tooth structure should be analyzed increased incidence of apical periodontitis; however,
thoroughly after removing the existing restoration/ the technical quality of the root canal preparation and

10
filling, if any. The presence of residual caries, cracks/ obturation has definite impact on the outcome of
fracture lines should also be examined before planning treatment as compared to technical quality of the
the root canal treatment. coronal restoration.

t.me/Dr_Mouayyad_AlbtousH
 140 Essentials of Endodontics

The prognosis of the tooth/teeth after endodontic • Restoration of the treated tooth (leakage-resistant
treatment must be taken into account in the treatment restoration preferred)
planning. Although the operator would like to • Measures to prevent the recurrence.
anticipate the prognosis as accurate as possible; Flowchart 10.2 displays the sequence of treatment
however, procedural errors and/or iatrogenic problems planning.
during endodontic procedures may change the
anticipated prognosis. The healing pattern may also Indications and Contraindications
vary in individuals; therefore correct prognosis might Endodontic treatment may be carried out in any tooth,
be difficult to predict. except when it is not contraindicated by the patient's
The treatment sequence (stages) may be planned as health; also the anatomy of that tooth permits the
follows: requisite instrumentation. The root canal treatment is
• Symptomatic relief of pain/swelling indicated where pulp and periapical tissues are
• Emergency pulp extirpation involved. It may be due to infection or traumatic
• Initiating root canal treatment (root canal opening injuries. In rare cases, intentional endodontic treatment
relieves pressure) is carried out to facilitate placement of restoration. It is
• Completion of root canal treatment (meticulous easy to enumerate the contraindications to root canal
preparation and adequate obturation) treatment than to list the indications.

Flowchart 10.2: Sequence of treatment planning

10

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 Endodontic Case Selection: Treatment Planning 141

The main contraindications are: 3. Incomplete development of the root apex (immature
• Non-restorable tooth: If the tooth cannot be restored apex). In such cases, achievement of hermetic apical
to function following root canal treatment (extensive seal is difficult due to persistent seepage from the
root caries, massive resorption, unfavorable periapical areas. Apexification should be attempted
crown-root ratio), extraction is inevitable followed and as the apical stop is created, the root canal can
by replacement options. be obturated. The tooth has to be kept under
observation. Regenerative treatment procedures are
• Grade III mobility and/or insufficient periodontal
also being tried to achieve vascularization in such
support.
teeth.
• Vertical root fracture; such teeth have poor 4. Root perforation: Perforation of the root surface can
endodontic prognosis. be accidental/iatrogenic or as sequel to internal/
• Tooth with no strategic importance even in future external resorption. In case of perforation, an effort
should not be root canal treated. should be made to induce repair by means of
The major contraindication in endodontics is ‘where mineral trioxide aggregate (MTA) and other
the tooth cannot be restored’; however, certain cases bioceramic materials. A surgical approach may be
warrant the operator to take extra care to carry out the necessary to wall off the perforation in some cases.
endodontic procedures. Additional treatment modalities 5. Uncontrolled/persistent periapical exudates: The
should be considered to achieve successful outcome of uncontrolled/persistent periapical exudate hinders
the treatment. The cases which warrant additional care with the success of root canal treatment. This is
are: generally managed by repeated dressings of
1. Extensive destruction of the periapical tissues: The calcium hydroxide/iodoform, creating alkaline
statement ‘excessive destruction’ is arbitrary; since, environment in the root canal. If seepage cannot be
an area of rarefaction of any extent can undergo controlled with an iodoform/calcium hydroxide
repair. It has been observed that the greater the dressings, then surgical intervention is warranted.
amount of bone destroyed, the less will be the likeli- 6. Root canal treated tooth exhibiting an acute infection: If
hood of repair. It is established that the periapical the infection persists, the root canal is to be re-
lesions less than 10 mm in diameter are more likely treated. The old filling is removed, the canals are
to show evidence of repair than those over 10 mm. enlarged, prepared and obturated again. Surgical
The involved tooth should be treated non-surgically intervention may be necessary in some failed cases.
and monitored until repair occurs; if no signs of 7. Foreign body in the periapical tissues: The presence of
healing, surgical intervention becomes necessary. a foreign body increases the difficulty of eliminating
In young individuals, repair of any rarefied area infection by intracanal treatment alone. Periapical
occurs more readily than in older ones. curettage should be carried out along with the root
2. Root canal obstructions (secondary dentin, a pulp stone canal treatment.
that cannot be removed/bypassed, a calcified/partially 8. Root fractures: Root fracture may not be a good
calcified canal, a malformed tooth, or a broken instrument): reason for endodontic treatment. The extraction of
In such cases, it is difficult to clean, disinfect and fractured segment is contraindicated if the pulp is
fill the root canal properly; subsequently, the vital and the tooth can be stabilized. When the
prognosis remains doubtful. The apical third of the fracture is in the apical third, with nonvital pulp,
root canal is critical and therefore must be prepared endodontic treatment should be carried out. When
and disinfected properly so that the micro- the apical fragment cannot be placed in line with
organisms harbouring in apical areas cannot reach the main root canal, the endodontic treatment is
the periapical tissues. If the apical portion of the completed till the fractured segment, and apical
canal is blocked, repair of the damaged bone is root tip is removed surgically. If an area of
unlikely to occur because microorganisms can rarefaction develops, the root fragment should be
egress into the periapical tissues and hinder with removed. The fractured segments can be stabilized
the repair process. In such cases, endodontic by using endodontic stabilizers.
treatment of the patent portion of the root canal is 9. Existing restorations: Full veneer crowns may not
completed and a retrograde apical filling is placed exhibit same anatomy as of the underlying crown,
to seal the remainder of the inaccessible root canal;
alternatively the blocked part of the root is removed
surgically.
creating difficulty in orifice location during
retreatment of failed endodontic case. In case of
long span bridges, it is always difficult to gain
10

t.me/Dr_Mouayyad_AlbtousH
 142 Essentials of Endodontics

access from the overlying restoration. All kinds of Systemic conditions affecting Endodontic treatment
existing restorations should be removed before • Asthma
initiating endodontic procedures. • Bleeding disorders
10. Malpositioning of tooth: Third molars, mostly • Cardiovascular diseases
maxillary third molars, are difficult to treat, • Diabetes
especially in patients with limited mouth opening. • Hypertension
Such teeth are usually tipped or rotated and pose • Medication
• Liver and kidney problem
difficulties in executing endodontic treatment. In
• Immunosuppressive drugs
extreme cases, extraction is the only option for the
• Pregnancy
clinicians.
11. Patient motivation: Patients should be self-motivated Physiological changes with age
and understand the importance of retaining a tooth • Behavior changes
in the arch. He/she should also be aware of the • Diet intake may be less
implications involved during and after endodontic • Oral and systemic health may deteriorate
treatment, including financial liabilities. Patients • Skin and blood vessels lose elasticity
must be convinced and fully trust the operator as • Delayed healing
regard outcome of the endodontic procedure. • Bones become brittle
• Alteration in taste/smell
SYSTEMIC DISEASES INFLUENCING • Change in tooth anatomy
• Variations in pulpal physiology
TREATMENT PLANNING
• Color changes
It has always been an area of concern for the dental • Continuous thickening of cementum
surgeons, precisely the endodontists, to decide whether • Gingiva becomes edematous and friable; loss of stippling
the tooth with necrosed pulp should be extracted or • Salivary flow decreases
treated. The focal infection theory is no longer accepted
as ‘explanatory’ for associating oral infection with The patient’s physician should be consulted before
systemic diseases. Certain systemic diseases do affect initiating endodontic treatment, especially elderly
pulp and periapical tissues, may be directly or patients and others suspected of any systemic involve-
indirectly. ment.
In deciding whether to retain or to extract a pulpless The systemic conditions which warrant extra
tooth, following features should be considered: attention before endodontic treatment are:
• Pulpless teeth generally do not contribute to systemic a. Cardiovascular diseases: When a patient has a history
disease. of rheumatic fever with valvular heart damage,
• Systemic diseases, such as active diabetes, tuber- endodontic treatment should be preferred rather than
culosis, etc. may affect healing pattern; potential for the extraction. Hypertensive and patient taking
repair is reduced in such patients, compromising anticoagulants are generally treated with utmost care.
with the treatment outcomes. Special consideration should be given to all such
• Extraction may be contraindicated because of an patients. In any case where the patient is at risk,
existing systemic condition of the patient, such as endodontic treatment should be carried out under
leukemia or radiation necrosis. antibiotic premedication. The recommended antibiotic
regime (Table 10.1) is as follows:
A thorough medical history should be recorded,
• 2.0 gm penicillin V, one hour before the procedure
analyzing the probability of any systemic disease.
followed by 1.0 gm every 6 hours postoperatively; or
Communicable diseases are also to be identified.
Table 10.1 Antibiotics regimen for cardiac patients
Communicable diseases
• Herpes Patient Drug (Dose)
• Hepatitis-B Conventional Er ythromycin (500 gm ever y
• HIV 6 hourly)
• Tuberculosis Ampicillin (1.0 gm every 6 hourly)
• Mumps Allergic to conventional Clindamycin (600 mg ever y

10
• Oral candidiasis medication 12 hourly)
(Transmissible through body fluids, such as blood and saliva, Azithromycin (500 mg ever y
pose great risk to the doctor and the staff.) 12 hourly)

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 Endodontic Case Selection: Treatment Planning 143

• 1.0 gm erythromycin, one hour before the procedure Patient’s gynecologist should be consulted as regard
and 500 mg every 6 hours postoperatively. treatment needs of the patient and also the drug regime.
Mouthwash with 5.0% betadine/chlorhexidine is • Proper chair position for the comfort of the patient.
advised before rubber dam placement to avoid any • Organogenesis is taking place in first trimester; any
possibility of bacteremia due to injury to gums. medication has to be cleared by the gynecologist.
Vasoconstrictors should not be administered to Second trimester is relatively safe. Third trimester is
patients with unstable angina, recent myocardial also safe but care has to taken with chair position as
infarction, recent stroke, recent arrhythmias and the fetus is growing and postural hypotension may
hypertensive patients. Local anesthetic agents without develop.
vasoconstrictor or minimal vasoconstrictors are
• To prevent supine hypotensive syndrome in the
preferred for nonsurgical endodontic procedures.
dental chair, the pregnant woman should have the
Vasoconstrictors should also be minimized in right hip elevated 10 to 12 cm or placing the patient
patient’s undergone coronary bypass surgery, in a 5.0 to 15% tilt on her left side can relieve pressure
especially in first three months. These patients may not on the inferior vena cava. If hypotension is still not
require antibiotic prophylaxis unless there are other relieved, a full left lateral position may be needed.
complications.
Patients with artificial heart valves are considered c. Malignant lesions: The presence of a well-defined
highly susceptible to bacterial endocarditis. Such apical radiolucency is assumed to be because of non-
patients should be given prophylactic antibiotics before vital pulp. Many a times, the radiolucency can be due
initiating endodontic treatment. to malignant lesions of the jaws mimicking periapical
It is a common belief that endodontic treatment radiolucency. For example, a definitive diagnosis of a
should be delayed in patients taking anticoagulant periradicular osteitis can be made only after biopsy.
therapy to prevent hematologic complications. Various Whenever, there is a discrepancy between initial
investigators do not support the routine withdrawal diagnosis and the clinical findings, the patient should
of anticoagulant therapy before endodontic treatment. be referred for second opinion. Patient undergoing
The endodontist must be familiar with local methods chemotherapy and/or radiation to the head and neck
of controlling hemostasis both during surgery and post- may have impaired healing responses (endodontic
operatively. The patient’s physicians should be treatment can be performed if the platelet count is more
consulted to alter the anticoagulant regime if need be. than 50,000/mm). The endodontic treatment should be
The patient should also be informed of the possible initiated in consultation with patient’s physician/
complications associated with anticoagulants and/or oncologist.
bleeding.
d. Human immunodeficiency virus (HIV): It has been
• Check whether hypertension is under control or not established that the potential of developing hepatitis
• Carefully administer local anesthesia. B/hepatitis C from a needle-stick injury is much higher
[Even though adrenaline is contraindicated in hyper- than developing HIV. A major consideration for the
tensives, amount available in 1:100000 solutions is safe. management of patients with HIV/acquired immuno-
As anesthetics without vasoconstrictors have a less deficiency syndrome (AIDS) is the CD4 lymphocyte
profound effect and shorter duration of action, slow count. Patients with CD4 count above 400 mm3 are
injection (one minute for 1.8 ml) using 26 or 27 gauge considered asymptomatic HIV candidates and can be
needle is preferred.] treated in routine. The endodontic procedures for HIV
infected patients can be initiated in consultation with
b. Pregnancy: Unless emergency treatment is warranted,
the medical specialist. The intake of medicine should
it is advisable to defer elective endodontic treatment,
also be noted and can be modified during endodontic
especially during the first trimester because of the
procedures.
potential vulnerability of the fetus. The second
trimester is the safest period during which any proce- e. Renal diseases (dialysis): Patient with renal failure
dure can be carried out. Treatment planning should and other kidney dysfunction may not be able to
be directed at eliminating pain symptoms during metabolize certain drugs. Hemodialysis tends to
pregnancy. aggravate bleeding tendencies through physical
The postpartum period, wherein the mother breast-
feed the child should also be considered. The clinician
should avoid any drug harmful to the infant.
destruction of platelets. It is important to review the
patient’s undergoing dialysis before initiating
endodontic procedures. The patients, who have had
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t.me/Dr_Mouayyad_AlbtousH
 144 Essentials of Endodontics

hemodialysis session generally have bleeding i. Blood dyscrasia: It is opined that endodontic proce-
tendencies and are fatigued. The elective endodontic dures are preferred in case of blood dyscrasias
treatment should be postponed till a day after (hemophilia, hyperthyroidism, Paget’s disease, etc.) as
hemodialysis. The operator should also be aware of the compared to extraction. Also, in patients with acute/
fact that hemodialysis removes certain drugs from the chronic leukemia and rheumatic heart diseases, the
circulating blood and can shorten the effect of endodontic treatment is preferred. The systemic dis-
prescribed medications. The drugs used during orders are not definite contraindications for executing
endodontic procedures may have to be avoided or their endodontic procedures; however, the operator should
doses are to be adjusted. Penicillin V and cephalexin be conscious of the implications of these diseases.
requires increase in dosage; however, erythromycin • Check bleeding and clotting time
requires no adjustment. The patient’s physician should • Less traumatic procedure should be carried out.
be consulted as regard specific drug requirements (Most challenging is to treat a patient with hemophilia as
during endodontic treatment. there is always the risk of puncturing blood vessel and
f. Epilepsy: Epileptic patients should take proper inducing internal bleeding particularly with inferior
medication before endodontic procedures. The alveolar nerve blocks. If vital pulp extirpation has to be
possibility of attack is to be minimized. Inadvertent carried out, gradual fixation of pulp tissue followed by
injection of local anesthetic into vein may trigger an removal in multiple visits is the preferred choice. Care
attack of epilepsy. should be exercised in placing rubber dam clamps so that
they do not impinge on gingival tissue. Notches may be
g. Diseases of adrenal cortex and thyroid: In case of placed on the labial and lingual surfaces into which the
low level of corticosteroids (Addison’s disease) and in clamps prongs will fit).
high level of corticosteroids (Cushing’s disease), the
j. Asthma
patient is unable to handle stress; also the healing is
impaired making the patient susceptible to infections. • Asthma, hay fever, skin rashes etc. indicate hyper-
In hypothyroidism, patients have diminished resistance sensitivity problems and the patients should be
to infection and in hyperthyroidism, epinephrine in managed accordingly.
local anesthetic may contribute to thyroid crisis. • The patient’s medication and nebulizer should be
Prophylactic antibiotics are effective during endodontic kept ready. The rubber dam application should be
procedures. modified and removed after short interval of time.
• Clinic set up should be aerosol free.
h. Diabetes: The controlled diabetic patients, free from • Patients with very high blood pressure need physician
complications like renal failure, hypertension and/or clearance and medication before anesthesia and even
coronary atherosclerotic disease, can be endodontically in routine procedures.
treated in routine. The standard protocol is followed,
wherein prophylactic antibiotics are prescribed. In case k. Medications
the patient does not respond to the prescribed • Whether patient is on medication: if yes, for which
antibiotics, culture sensitivity tests can be performed; problem?
subsequently, modifying the antibiotic prescription. • Whether the medication was prescribed by any
The appointments in endodontic clinic should be qualified doctor? This helps in identifying patient
scheduled considering the patient’s normal meal and attitude towards his/her ailments.
insulin schedule protocol. A treatment plan that (Some medication may be interfering with the antibiotics
includes periradicular surgery requires consultation and analgesics, need to be analyzed.)
with the patient’s physician to review the systemic • Allergic to any drug.
implications and also the schedule of drugs.
• Check whether diabetes is under control or not (stage PERIODONTAL DISEASES INFLUENCING TREATMENT
of diabetes) PLANNING
• Patients with diabetes are prone to infection and Certain cases, such as a combined periodontic-
delayed healing; hence, necessary precautions endodontic lesion (an infected pulpless tooth
should be taken communicates with the periodontal tissues or

10 • Schedule early morning appointments where the

patient has had medication and meals, so that the
risk of hypoglycemia is minimized.
periodontal infections communicate to the pulp tissues)
should be planned keeping in mind the timings of
treating one tissue and its effect on the other tissue. It

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 Endodontic Case Selection: Treatment Planning 145

is established that if destruction of the periodontal When more than one focus of infection is present
attachment is considerable, the periodontal fibres may in the oral cavity, each one should be treated in
not get repaired even after endodontic treatment. coordination. Such a situation arises when two adjacent
In case of severe periodontal involvement, extensive untreated pulpless teeth are present, or when pulpal
alveolar resorption and/or unfavorable crown-root and periodontal disease of the same tooth are coexistent,
ratio, the planning should be aimed at improving the or when sinus is also involved along with rarefaction,
periodontal status of the tooth. In case of class III especially in molars.
mobility, extraction of the tooth should be preferred The existing ailments should be treated in coordina-
because the prognosis of the periodontal repair may tion to achieve better treatment outcome.
remain poor even after the endodontic treatment. The treatment planning is summarized in
However, if the tooth is firm despite of the radiographic Flowchart 10.3.
evidence of bone resorption, endodontic treatment is
not contraindicated. FINAL PHASE OF TREATMENT PLANNING
An effort should be made to determine whether the
concerned tooth is strategically important or not. This The final phase of case selection and treatment planning
is important in case the patient is already wearing a involves considering the following factors:
partial denture, or a partial denture is being planned i. Restorability of the tooth
for the patient. Extraction of the tooth in such cases may ii. Strategic value of tooth in the oral cavity
allow for a better design of denture, save time and be iii. Periodontal factors
more economical in the long run. iv. Patient preference
Flowchart 10.3 Treatment planning

10

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 146 Essentials of Endodontics

i. Restorability of the tooth: The purpose of endodontic important decision that impacts the quality of the
therapy is to provide biologically acceptable restoration patient care. Similarly, the beginners in the field of
that will support the stomatognathic system. endodontics should also assess the patient accordingly.
The tooth must be assessed for any restorative The decision depends on case to case by taking into
challenges that may create difficulty in restoration or account the local and systemic conditions of the patient
make the tooth unrestorable following root canal as well as the prognosis of the planned treatment.
treatment. If the tooth cannot be restored to its functions To provide guidance on how to evaluate an endo-
(reasons may be extensive root caries, massive dontic case, the American Association of Endodontists
resorption or unfavorable crown-root ratio), the (AAE) has created an Endodontic Case Difficulty
endodontic treatment should not be planned. Assessment Form (the assessment form is modified for
convenience) that helps the operator to evaluate the
ii. Strategic value of tooth in the oral cavity: The
difficulty of each case and weight it against their endo-
strategic considerations include structural integrity,
dontic experience.
morphology and dimensions of the root, level of
The level of difficulties are categorized as minimum,
surrounding bone/periodontal support and the
moderate and high difficulty.
remaining tooth structure. The tooth having no function
in the oral cavity or even in future should not be • Minimum difficulty: Patient is cooperative; no
planned for endodontic treatment. The strategic value systemic, physical or psychological problems. Patient
of tooth vis-à-vis overall functioning of the exhibiting normal morphological features; conven-
stomatognathic system should be given priority in tional diagnosis along with normal associated
treatment planning. tissues. (Budding clinician with limited experience
can achieve predictable treatment results.)
iii. Periodontal factors: The health of the periodontium • Moderate difficulty: Patient is cooperative, but anxious,
affects the long-term prognosis of the endodontic treat- with mild/moderate systemic, physical and psycho-
ment. Insufficient periodontal support is considered as logical problems. Presence of aberrant root canal
contraindication to root canal treatment. Periodontal morphology, curved canals, etc.; periodontal tissues
management of the concerned tooth and the rest of may involve (only experienced and skilled clinician
dentition is important for long-term success of the can achieve predictable treatment results).
planned endodontic procedure. • High difficulty: Uncooperative patient with moderate/
iv. Patient factors: Many a times, may be because of severe systemic, physical and psychological
lack of awareness or financial constraints, patient prefer problems. Presence of extremely inclined teeth/
extraction rather than curative treatment. Medical severely curved canals; previously failed treatment
conditions may also complicate the healing process or (separated instruments, perforations, etc.); perio-
may make the patient unable to open mouth or sit for dontal tissues also involved (clinician should assess
long. Medical conditions are usually not contra- his/her skill, otherwise patient can be referred to
indicated; however, certain modifications may be skilled/experienced operator).
required. The operator should take into consideration Each case is assessed to determine the level of difficulty.
whether the patient will be able to tolerate the If the level of difficult exceeds the skill and expertise of
treatment, patient’s expectation and also the patient's the operator, the patient can be considered for referral.
ability to afford the professional fee, before planning The modified Endodontic Case Difficulty Assessment
for endodontic procedure. Form (Table 10.2) can quickly discover what factors
make root canal treatment more complex; provide
Issues to consider judgment for referral, so as to improve quality care to
• Restorability of the tooth the patients.
• Strategic value of tooth in the oral cavity The assessment form makes case selection efficient,
• Periodontal factors consistent and easier to document. The same can be
used for record keeping and also for the purpose of
• Patient factors
‘referral’.
The assessment form describes certain conditions,
TO REFER OR NOT TO REFER: CLINICAL PROTOCOL which can complicate the root canal treatment or can

10 The general practitioner frequently encounter patients

requiring root canal treatment. Whether these patients
be referred to an endodontist or be treated locally is an
adversely affect the treatment outcome. The risk factors
can influence the ability of operator to provide adequate
care at a consistently predictable level.

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 Endodontic Case Selection: Treatment Planning 147

Table 10.2 Endodontic Case Difficulty Assessment Form (Adapted from American Association of Endodontists)
Criteria Minimum difficulty Moderate difficulty High difficulty
A. Patient considerations
Medical history No medical problem One/few medical problems Complex medical problem/serious
illness/disability
History of allergies • No history of reactions to • Intolerance to vasoconstrictors • Anesthetic medicaments not
anesthetic agents • Allergic to certain drugs suitable
• No history of allergy • Allergic to plenty of objects/drugs
Patient cooperation • Cooperative and compliant • Anxious but cooperative • Uncooperative
• No problem of mouth • Slight limitation in mouth • Significant limitation in mouth
opening opening opening
• No problem of gag reflex • Gags occasionally • Extreme gag reflex
Emergency conditions Minimum discomfort (pain/ Moderate pain/swelling Severe pain/swelling
swelling)

B. Treatment considerations
Diagnosis Signs and symptoms consistent Extensive differential features Complex signs and symptoms
with diagnosis (diagnosis easily (diagnosis not easily achieved at) (difficult to diagnose)
arrived at)
Radiographic Obtaining/interpreting radio- Difficulty in obtaining/interpreting Superimposed anatomical structure;
assessment graphs easy radiographs (problem of mouth pose difficulty in interpreting radio-
opening) graphs
Position of tooth Anterior teeth (may be slight Premolars/first molar [may be 2nd or 3rd molar [may be extreme
inclination/ rotation moderate inclination/rotation inclination/rotation (more than 30°)]
(less than 10°) (10–30°)]
Ease of Isolation Rubber dam placement in Modification required for rubber Extensive modification required or
routine dam placement rubber dam placement not feasible
Accessibility Normal crown morphology • Full coverage restoration Significant deviation from normal
• Extensive coronal destruction tooth (dens-in-dente, fusion, etc.)
Root canals morphology • Straight or curvature less • Moderate curvature (10–30°) • Extreme curvature (more than 30°)
than 10° • Canals partially visible or S-shaped curve
• Canals visible in radiographs • Canal divides in the middle or
apical third
• Deviated canal morphology
• Canals not visible
Resorption No resorption Minimal apical/ Internal/External Extensive apical/internal/external
resorption resorption

C. Miscellaneous considerations
Traumatic injuries • No fracture • Complicated crown fracture • Complicated crown fracture
• Uncomplicated crown fracture • Subluxation/Intrusion • Horizontal root fracture
• Luxation
• Avulsion
Endodontic treatment No previous treatment Previous treatment without • Previous treatment with complica-
complications tions (e.g. Per foration, non-
negotiated canal, ledge, separa-
ted instrument)
• Surgical intervention required
Periodontal-endodontic None or mild periodontal Moderate endodontic/ • Concurrent endodontic/perio-
condition involvement periodontal involvement dontal involvement
(may be concurrent) • Root amputation/hemisection
prior to endodontic treatment 10

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 148 Essentials of Endodontics

A few clinicians prefer to concentrate on restorative The ASA classification is widely used to assess pre-
dentistry and avoid endodontics; whereas, others opt anesthetic condition of the patient. The clinician should
to treat endodontic cases of minimal to moderate also consider associated factors such as age, obesity,
difficulty. Even budding endodontists do not prefer etc. before initiating endodontic procedures under
‘enthusiastic endodontic intervention’. general anesthesia.
Over the years, with the advent of operating micro-
scope and other gadgets, the clinicians are now BIBLIOGRAPHY
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difficult and warrant the clinician to opt for referral planning. Br. Dent. J.: 2004; 197:231–238.
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3. Curtis DA, Lacy A and Chu R. Treatment planning in the 21st
• Extreme inclination/rotation of the tooth century: what's new? J. Calif. Dent. Assoc.: 2002; 30:503–510.
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• Radiographic obliteration of pulp chamber and root implantology: To extirpate or integrate? Aust. Endod. J.: 2006;
32:57–63.
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5. Friedman S and Mor C. The success of endodontic therapy –
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healing and functionality. J. Calif. Dent. Assoc.: 2004;
anatomy 32:493–503.
• Retreatment of a case restored with post-core 6. Friedman S. Considerations and concepts of case selection
restoration. in the management of post-treatment endodontic disease
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too under general anesthesia, the anesthetist should 7. Friedman S. Prognosis of initial endodontic therapy. Endod.
be consulted in every case; surgery should be carried Topics: 2002; 2:59–88.
out under the supervision and instructions of the 8. Heling I, Gorfil C, Slutzky H, Kopolovic K, Zalkind M, Slutzky-
anesthetist. Golberg I. Endodontic failure caused by inadequate
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tions. J. Prosth. Dent.: 2002; 87:674–678.
classified patients undergoing surgical interventions
with general anesthesia. 9. Iqbal MK and Kim S. A review of factors influencing treatment
planning decisions of single-tooth implants versus preserving
Class 1: No systemic illness. Patient healthy: No natural teeth with non-surgical endodontic therapy. J. Endod.:
modification required in dental treatment. 2008; 34:519–529.

Class 2: Patient with mild degree of systemic illness; 10. John V, Chen S and Parashos P. Implant or the natural tooth
– A contemporary treatment planning dilemma? Aust. Dent.
but without functional restrictions (well-controlled
J.; 2007; 52:S138–50.
hypertension, diabetic, asthma, etc.): Usually no
modification required in dental management. 11. Kirkevang LL and Horsted BP. Technical aspects of treatment in
relation to treatment outcome. Endod. Topics: 2002; 89–102.
Class 3: Patient with severe degree of systemic illness 12. Marshall FJ. Planning endodontic treatment. Dent. Clinic.
which limits activities; but does not immobilize the North Am.: 1979; 23:495–518.
patient (cardiovascular diseases, unstable angina, 13. Messer HH. Clinical judgement and decision making in
hemophilia, etc.): Require modifications in dental endodontics. Aust. Endod. J.: 1992; 25:124–132.
management and in drug intake.
14. Ng Y, Mann V, Rahbaran S, Lewsey J and Gulabivala K.
Class 4: Patient with severe systemic illness that Outcome of primary root canal treatment: Systematic review
immobilizes the patient; may sometimes be life of the literature-Part I. Effects of study characteristics on
threatening (kidney failure, liver failure, etc.): Require probability of success. Int. Endod. J.: 2007; 40:921–939.
definite modifications in dental management. 15. Ng Y, Mann V, Rahbaran S, Lewsey J and Gulabivala K.

10 Class 5: Patient may not survive for more than 24 hours;

whether or no surgery.
Outcome of primary root canal treatment: Systematic review
of the literature-Part 2. Influence of clinical factors. Int. Endod.
J.: 2008; 41:6–31.

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 Endodontic Case Selection: Treatment Planning 149

16. Ng YL, Mann V and Gulabivala K. Outcome of secondary 20. Ree MH, Timmerman MF and Wesselink PR. An evaluation
root canal treatment: a systematic review of the literature. of the usefulness of two endodontic case assessment forms
Int. Endod. J.: 2008; 41:1026–1046. by general dentists. Int. Endod. J.: 2003; 36:545–555.
17. Ng YL, Mann V and Gulabivala K. Tooth survival following 21. Ricucci D, Grondahl K and Bergenholtz G. Periapical status
non-surgical root canal treatment: a systematic review of the of root-filled teeth exposed to the oral environment by loss
literature. Int. Endod. J.: 2010; 43:171–189. of restoration of caries. Oral Surg., Oral Med., Oral Pathol.,
Oral Radiol. Endod.: 2000; 90:354–359.
18. Parirokh M, Zarifian A and Ghoddusi J. Choice of treatment
plant based on root canal therapy versus extraction and 22. Saunders WP. Treatment planning the endodontic-implant
implant placement: a mini-review. Iran. Endod. J.: 2015; interface. Br. Dent. J.: 2014; 216:325–330.
10:152–155. 23. Tang CS and Naylor AE. Single-unit implants versus
19. Pothukuchi K. Case assessment and treatment planning: what conventional treatments for compromised teeth: a brief review
governs your decision to treat, refer or replace a tooth that of the evidence. J. Dent. Educ.: 2005; 69:414–418.
potentially requires endodontic treatment? Aust. Endod. 24. Yeng T, Messer HH and Parashos P. Treatment planning the endo-
J.:2006; 32:79–84. dontic case. Aust. Dent. J. Endod. Suppl.: 2007; 52:S32–S37.

10

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Chapter
11
Endodontic Instruments

The successful endodontic procedures are being Ingle proposed standardization of instruments after
achieved by use of various instruments, strictly getting consent from other manufacturing units. The
following the biological principles. Over the years, the proposal was:
hand instruments with one make or the other, have been • Instruments shall be numbered from 10 to 100, the
successful in achieving the biological healing of numbers to advance by 5 units to size 60 then by
periapical tissues. In the recent past, automated and 10 units to size 100 (later number up to 140 were
mechanized instruments are being tried to improve accepted).
upon the speed and efficiency of the treatment. The • Each number shall be representative of diameter of
design of basic hand instrument was patented by Kerr instrument in 100th of mm at the tip (No. 10 is 10/
company in 1915, comprising 2% taper and 16 mm long 100 or 0.1 mm at tip).
cutting surfaces. • The flutes shall begin at the tip [designated as D1(D0)]
Later, flexible nickel-titanium (Ni-Ti) instruments and shall exactly extend 16 mm up the shaft,
were introduced. They are both engine driven and hand [designated as D2(D16)] [D0 and D16 denote length while
instruments. The advent of rotary instruments with D1, D2 denote diameter]. The diameter of D2 shall be
respective advantages and disadvantages, have 0.32 mm greater than D1. This sizing ensures a constant
revolutionized the endodontic treatment procedures. increase in taper of 0.02 mm per mm (Fig. 11.1).
The knowledge of anatomy and basic biological • The tip angle of an instrument should be 75° ± 15°.
principles coupled with use of modern instruments has • Instrument size should increase by 0.05 mm at D1
led to predictably better quality of root canal treatment. between no. 10 and 60. The increase is 0.1 mm from
The International Organization for Standardization no. 60 to 100.
(ISO) and American National Standard Institute (ANSI) • Instrument handles be color coded (Fig. 11.2).
pertain to standardization of endodontic instruments. Later, the greater taper instruments having taper
ISO deals with instruments for preparation (No. 3630-1) more than 2% were introduced. They were available in
and obturation (No. 3630-3) of root canal; whereas, 4, 6, 8 and 10% taper. This means that for every mm
ANSI denotes different numbers for different gain in length of cutting blade, width of instrument
instruments. ANSI designated instruments as: K-type increases by 0.04, 0.06 and 0.08 mm/mm rather than
files and reamers (no. 28). Hedstrom files (no. 58). earlier standard of 0.02 mm/mm. These new
Barbed broaches and Rasps (no. 63) and condensers, instrument allow for greater coronal flaring than 0.02
pluggers and spreaders (no. 71). instrument. Instrument having half sizes, i.e. 12.5, 17.5,
22.5, 27.5, 32.5 and 37.5 have also been introduced.
STANDARDIZATION OF ENDODONTIC INSTRUMENTS
Earlier the root canal instruments were manufactured
without adhering to any pre-established criteria. No
definite specification regarding diameter, taper or
length of cutting blades were followed. Significant
differences in configuration of instrument of same sizes
were observed when they were measured with a μm-
measuring scope. Fig. 11.1 ISO standardization

150

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 Endodontic Instruments 151

MAKE OF ENDODONTIC INSTRUMENT

Earlier instruments were made of carbon steel and
stainless steel. These instruments were having good
cutting efficiency; however, they lack flexibility. Nickel-
titanium alloy was introduced in dentistry by Naval
Ordinance Laboratory, earlier known as nitinol. Earlier
nickel and titanium were added in the ratio of 50 : 50.
Later nickel (54–56%) and titanium (44–46%) were
found to be more effective and useful for endodontic
use. Traces of cobalt and boron have been added to
improve surface hardness. 5.0% aluminium was added
at the expense of nickel to improve upon the cutting
efficiency; however, these instruments did not show
much improvement in cutting efficiency, more so, they
lack super-elasticity.
Fig. 11.2 Color coding of K-files There are two basic categories of Ni-Ti rotary
instruments: Active and passive. ‘Active instruments’
The full extent of shaft (up to handle) comes in
have active cutting blades; whereas, ‘passive instruments’
3 lengths, i.e. short (21 mm), standard (25 mm) and long
have a radial land between cutting edge and flute.
(31 mm). The size of the instrument, their corres-
ponding color and diameter at D1 and D2 is depicted in Active instruments cut more effectively and
Table 11.1. aggressively and have a tendency to straighten the canal
curvature. Passive instruments perform a scrapping or
Instrument sizes, diameter at D1 and D2 and color
burnishing rather than a real cutting action; remove
Table 11.1
coding dentin slower and have less tendency of canal
Instrument size D1 (mm) D2 (mm) Color of handle
straightening. Profile, light speed, etc. are ‘passive
instruments’ and Flexmaster, RaCe, Protaper, Hero 642,
06 0.06 0.38 Pink
K3 etc. are ‘Active instruments’.
08 0.08 0.40 Gray
The comparison of stainless steel and Ni-Ti instru-
10 0.10 0.42 Purple
ments is tabulated in Table 11.2.
15 0.15 0.47 White
20 0.20 0.52 Yellow
25 0.25 0.57 Red Table 11.2 Comparison of Ni-Ti and stainless steel instruments
30 0.30 0.62 Blue Ni-Ti Stainless steel
35 0.35 0.67 Green Softer than stainless steel Harder than Ni-Ti
40 0.40 0.72 Black Not heat treatable Heat treatable
45 0.45 0.77 White
Have low modulus of elasticity Have high modulus of
50 0.50 0.82 Yellow elasticity
55 0.55 0.87 Red
Show super-elasticity and shape Do not show elasticity and
60 0.60 0.92 Blue
memory sharp memory
70 0.70 1.02 Green
More flexible (two to three times Not flexible
80 0.80 1.12 Black
than stainless steel)
90 0.90 1.22 White
Resist fracture Fracture easily
100 1.00 1.32 Yellow
Good corrosion resistance Corrosion resistance fair
110 1.10 1.42 Red
120 1.20 1.52 Blue Better biocompatibility Biocompatibility fair
130 1.30 1.62 Green Cutting efficiency less Cutting efficiency more
140
150
1.40
1.50
1.72
1.82
Black
White Gives no indication of fracture
(60% more than Ni-Ti)
Gives indication of fracture 11

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 152 Essentials of Endodontics

EVOLUTION OF NICKEL-TITANIUM INSTRUMENTS clockwise and counter clockwise movement may not
Over the years the researchers have been trying to cut as efficiently as a same-size rotary file. The augering
improve upon the make and shape of Ni-Ti instruments of debris with these files is also limited.
so as to achieve the requisite root canal preparation Self-adjusting files (SAF) were introduced, having
without any procedural error; and also without compressible open tube design that exerts uniform
affecting the surrounding periodontium. The evolution pressure on the dentinal walls, regardless of the cross-
is categorized as: sectional configuration of the canal.
The single-file concept, WaveOne and RECIPROC
First Generation (VDW), drives the file in unequal clockwise and counter
The first generation Ni-Ti files have passive cutting clockwise direction. This reciprocating movement
radial lands and tapers of 4 and 6%. The passive radial allows a file to efficiently cut along with augering the
land facilitates a file to stay centered in canal curvatures debris effectively.
during root canal preparation. Earlier instruments
Fifth Generation
required numerous files to achieve the preparation
objectives; later greater taper (GT) files became The fifth generation design is such that the center of
available, (taper of 6, 8, 10 and 12%). The ‘passive radial mass and/or the center of rotation are offset. In rotation,
land’ is the important characteristics in first generation offset design produce a mechanical wave of motion that
instruments. travels along the active length of the file. Such
instruments enhance augering debris out of the canal
Second Generation and improves flexibility.
The second generation of Ni-Ti rotary files require fewer The examples of such designs are Revo-S (Medidenta),
instruments to prepare a canal. To minimize screw One Shape, and ProTaper next.
effect, EndoSequence and RaCe instrument system
provide files with alternating contact points. These files TERMS USED WITH ENDODONTIC INSTRUMENTS
have fixed taper along the active blades. The advent of The reader should have clear concept of the 'terms' used
ProTaper (multiple increasing/decreasing percentage with endodontic instruments for better understanding
tapers) revolutionized the file design. The system of the working of these instruments.
provides shorter sequence of files to adequately shape The terms are:
the canal walls. Elastic limit: Elastic limit is the maximum stress that
To increase resistance to fracture, the files are can be applied to a metal without producing permanent
electropolished to remove surface irregularities; deformation. When external forces act on a metal, they
however, electropolishing may lead to dullness of the tend to form internal stresses, which cause deformation.
sharp cutting edges. Different cross-sectional designs If the stresses are not much, the metal will return to its
were tried to improve upon the cutting efficiency of original dimensions on removal of the stresses.
these instruments.
Stress: The force acting across a unit area in a solid
Third Generation material (stress is quotient of force divided by an area).
The third generation instruments focused on utilizing Strain: The amount of deformation a metal undergoes
heating and cooling methods to reduce cyclic fatigue is termed strain.
and improve safety. The desired phase transition Elastic deformation: The reversible deformation that
between martensite and austenite can be utilized to does not exceed the elastic limit.
produce a more optimal metal. Examples of files that Shape memory: Shape memory is the property whereby
offer heat treatment technology are twisted file (Axis/ the alloys when heated returns to their original shape
SybronEndo), HyFlex (Coltene), Vortex, and WaveOne after having been deformed.
(Dentsply Tulsa Dental).
Taper: Taper is the amount of instrument diameter
Fourth Generation increase each millimeter along its working surface from
The next generation Ni-Ti instruments utilizes tip to the handle.
reciprocation (repetitive up and down/back-and-forth Core: Core is the cylindrical center part of the instru-

11 motion). M4 (Axis/SybronEndo), and Endo-Eze

(ultradent products) are examples of systems that use
reciprocation. A reciprocating file that utilizes an equal
ment. The circumference is bordered by the depth of
flutes. The diameter of the core is important in
determining the flexibility and resistance to torsion.

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 Endodontic Instruments 153

Helix angle: The angle that the cutting edge makes with susceptible to fracture. The stress concentration in alloy
the long-axis of the instrument is called helix angle. metallurgy lead to flexure fatigue and subsequent
fracture.
Flute: Flute is the groove in the working surface
between the cutting blades. The soft tissues and dentin b. Factors predisposing to fracture
tips are collected here from the canal walls. The rotary Ni-Ti instrument can fracture because of
incorrect or excessive use. Many other factors also
Land: The land is the surface that projects axially from
predispose to fracture of these instruments. The factors
the central axis as far as cutting edge between the flutes
affecting susceptibility for fracture of rotary Ni-Ti
(plane surface immediately following the cutting edge).
instruments are:
It is also known as marginal width.
i. Manufacturing process: During manufacturing of
Relief: The surface area of the land that rotates against Ni-Ti alloy, a variety of inclusions (oxide particles),
the canal wall may be reduced to form relief. The relief may get incorporated into the metal resulting in
reduces the frictional resistance and also aid in protecting their weakness. Manufacturing process even results
the instrument from over engagement and separation. in many irregularities, which act as areas of stress
concentrations and crack initiation during use. Ion
Pitch: It is the space or distance between one cutting implantation and electropolishing methods are
edge and the corresponding adjacent cutting edge along used to improve the strength of rotary Ni-Ti
the working area. The smaller the pitch, the more spirals instruments.
the file will have and also the greater helix angle.
ii. Instrument design: The design of instrument may
Rake angle: If is the instrument is sectioned perpendi- affect its resistance to fracture, especially when
cular to the long-axis, the angle formed by cutting edge subjected to flexural/torsional load. An increase in
and the radius of the instrument is the rake angle. The cross-sectional area may contribute to increased
cutting edge has two surfaces: the rake face (surface of resistance to torsional failure. It has been reported
the cutting blade on the leading edge) and the clearance that instrument with a U-flute design and smaller
face (surface of the blade on the trailing side). If the cross-section area are more flexible than the
angle formed by the cutting edge (rake face) and the triangular helix design.
surface to be cut is obtuse, it is ‘positive rake angle’. If The design features that affect instrument fracture
the so angle is acute it is ‘negative rake angle’. If the angle include instrument taper, size of cutting blade,
is 90°, this is radial rake angle (neutral rake angle). The number and depth of flutes, etc.
positive rake angle is for ‘cutting’ and the negative rake iii. Frequency and speed of instrument use: The speed
angle is for ‘scrapping’. at which instruments operate may not have any
Sometimes the term ‘cutting angle’ is used, which is effect on the number of cycles to fracture; however,
the angle formed by the cutting edge and the radius higher speed reduces the period of time required
when the instrument is sectioned perpendicular to the to reach the maximum number of cycles before
cutting edge. fracture.
Light apical pressure and brief use in the canal
FRACTURE OF Ni-Ti INSTRUMENTS may contribute to prevention of fracture of rotary
The prevalence of mean clinical fracture frequency of Ni-Ti instruments.
rotary Ni-Ti instruments is approximately 1.0% with a iv. Preparation technique: The clinician need to
range of 0.4 to 3.7%. develop modified instrumentation sequences to
Considerable research has been carried out to under- avoid binding and threading of instruments in the
stand mechanism of alloy failure and also to minimize root canal; sequential use of instruments is
operator related issues of fracture of instruments. The preferred in routine. Preflaring of the root canal
main causes of fracture of endodontic instruments with hand instruments before use of rotary Ni-Ti
(Ni-Ti) are: instrument creates a glide path for instrument tip
and is a major factor in reducing the fracture rate
a. Metallurgy of Alloy of rotary Ni-Ti instruments.
Nickel-titanium alloys are popular because of their v. Root canal curvatures: As the radius of curvature
biocompatibility and corrosion resistance. One of the
disadvantage of Ni-Ti alloy is its low tensile and yield
strength compared with stainless steel, making it more
decreases or the angle of curvature increases, the
chances of file fracture, even with fever rotation is
increased.
11

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 154 Essentials of Endodontics

The prolonged clinical use of rotary Ni-Ti instru- The easy way to classify endodontic instruments is
ments significantly reduces their cyclic flexural according to their sequence of usage. The instruments
fatigue resistance. Partially fatigued instruments are classified as:
when flexed, reveal fractures associated with A. Diagnostic instruments
surface flaws. No correlation has been found B. Exploring instruments
between number of uses and frequency of fracture C. Extirpating instruments
of instruments. D. Shaping instruments
vi. Sterilization procedures: The influence of steriliza- E. Obturating instruments
tion of instruments on their resistance to fracture is
F. Miscellaneous.
still uncertain; may not be an important factor as
regards fracture of Ni-Ti instruments.
A. DIAGNOSTIC INSTRUMENTS
Traditional instruments used in conventional operatory
CLASSIFICATION OF ENDODONTIC INSTRUMENTS
are modified for endodontic use. A typical set of endo-
Different classifications for endodontic instruments dontic instruments include a mouth mirror, endodontic
have been proposed by various authors; however, explorer, cotton pliers, spoon excavators, spreaders/
none is universally accepted. The earlier classifications pluggers, plastic instrument, hemostat, periodontal
are: probe and a ruler.
A number of specialized devices are necessary to
a. Harty’s classification
evaluate the status of pulp and the surrounding tissues.
i. Instruments used for access cavity preparation Magnifying loops and microscopes are used to enhance
• Basic instruments the visibility and improve upon the diagnostic skills.
• Rubber dam Pulp vitality testers and the radiographic equipment is
• Burs described in Chapter 9.
ii. Instruments used for root canal preparation
B. EXPLORING INSTRUMENTS
• Hand instruments
• Power assisted instruments i. Smooth broach: The smooth broaches are used to
explore the patency of root canals (Fig. 11.3). These
• Electronic measuring devices
are tapered instruments made of soft steel. The
• Instruments for retrieving broken instruments/ conventional taper is 0.007–0.01 mm/mm with
posts variable lengths.
iii. Instruments used for filling root canals ii. DG16 and JW17 microexplorer: Conventionally DG-
iv. Equipment used for storing instruments 16 explorer (named after the scientist, David green)
v. Equipment for sterilization of endodontic instru- was used to explore the root canals; however, its
ments diameter at the tip was large enough to penetrate
vi. Equipment for improving visibility. narrow canals (Fig. 11.4). JW 17 microexplorer is
narrower than DG16 and easily penetrates the
b. Grossman’s classification canals (Fig. 11.5). It slides through the mud or
i. Exploring instruments collagen collected at the opening of the canal;
• Smooth barbed broach whereas, DG16 may push the mud/collagen more
apically. Modified forms of DG16 explorer are also
• DG-16 explorer
being used. (DG 16/17 and DG 16/23). Another
ii. Debriding instruments
• Barbed broaches
iii. Shaping instruments
• Reamers
• Files
iv. Obturating instruments
• Plugger
11 • Spreader
• Lentulo spirals. Fig. 11.3 Smooth broach

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 Endodontic Instruments 155

C. EXTIRPATING INSTRUMENTS
i. Barbed broaches and rasps
Broach is a tapered instrument made of soft steel. In
case of barbed broach, the shaft is notched by a shredder
Fig. 11.4 DG 16 microexplorer
to produce sharp barbs extending outward from the
shaft.
The barbed broaches are used to remove soft tissues,
cotton and paper points, etc. (Fig. 11.8). The barbed
broaches are available in three sizes depending upon
the configuration of barbs. These are ‘X’ (coarse), ‘XX’
Fig. 11.5 JW microexplorer
(medium) and ‘XXX’ (fine). Recently, seven types of
color coded broaches have been introduced. Black
(coarse), green (medium), blue (fine), red (extra
fine – XF), yellow (double extra fine – XXF), white (triple
extra fine – XXXF) and purple (quadri extra fine
XXXXF).
The instrument is carefully inserted through the
access cavity, till approximate canal length is reached.
The broach is slightly withdrawn, then rotated a few
revolutions and removed. The soft tissue and debris
get engaged on barbs and is removed. The canal is
débrided of bulk contents before further preparation.
The instrument should never be inserted with force.
Once the dentin wall is felt, the broach should not be
Fig. 11.6 Pathfinder pushed further. The broach should be used in canals
which are at least 20–25 number file size. Vital pulps,
explorer KC-33, much heavier and sturdier, is also being low in collagen, are difficult to remove in toto
available for canal exploring. with broaches. Formaldehyde treated pulps become
fibrous and can be removed easily using barbed
iii. Pathfinder files: The smaller number files (No. 6 and 8)
broaches.
are used to negotiate the patency of root canals,
known as pathfinders (Fig. 11.6). Size of the broach is important. Too wide a broach
may push the pulpal tissue apically and may bind in
iv. Micro-opener: Micro-opener is K-file having greater
the canal and subsequently break. Too narrow a broach
taper characterized by a shank that is bent at an
may not be able to engage the pulpal tissue properly.
angle of about 200° along with a long plastic handle.
Many a times, two small broaches are inserted and
It is ideal for the posterior teeth. The Micro-opener
twisted in the root canal, thereby engaging and
series comprises three instruments with tip
removing the pulp tissue.
diameter 0.10, 0.15 and 0.20 mm and a taper of 0.02,
0.04 and 0.06 respectively (Fig. 11.7a).
v. Micro-debrider: Micro-débrider is Hedstrom file
characterized by a shank that is bent at an angle of
200° along with a long plastic handle. They are
available in ISO sizes, 20 and 30 and taper 0.02
(Fig. 11.7b).

11
b

Fig. 11.7 (a) Micro-opener; (b) Micro-debrider Fig. 11.8 Barbed broach

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 156 Essentials of Endodontics

Barbed broaches and rasps, although similar in

design, have significant differences in taper and barb
size. The barbed broach has a taper of 0.007–0.010 mm/
mm and rasp has a taper of 0.015–0.020 mm/mm. The
barb height is much larger in broach than in rasp. The
barb of broach comes out of instrument core, so barb is
a much weaker instrument than rasp (Table 11.3).
Disadvantages
• Barbs are the weak links; may break within the canal
• Do not help in preparation of root canal.

D. SHAPING INSTRUMENTS
The basic instruments used for cleaning and shaping,
as designed by Kerr Company are reamers, files and
Hedstrom files.
Fig. 11.9 Reamer (left) has lesser flutes than file (right)
i. Reamers
different color of the number, e.g. in size 30 reamer,
Reamers are identified by a ‘triangle’ symbol on the 30 is written in white color on top of the handle;
handle. These are manufactured by twisting stainless whereas, in flexoreamer, 30 is written in blue color on
steel wire into triangular blanks to produce cutting top of the handle.
edges. Because each angle of blank is approximately
60°, a sharp knife edge is available to shave the canal ii. Files
walls. The cross-sectional area of blank allows a fair
Files are identified by a ‘square’ symbol on the handle.
degree of flexibility in the reamer. The reamer has lesser
The triangular blank of reamer is replaced with square
flutes per unit length than file (Fig. 11.9). Being less
blank in files and was twisted more to give greater
twisted, it is more flexible than file. The instrument has
number of cutting edges (Fig. 11.10).
cutting tip which makes the reamer suitable for straight
The square blank has an angle of 90°; the cutting
canals only. In curved canals, ledge can occur if the
efficiency is less than reamer. A reamer has one to one
instrument is not precurved.
and a half flute per mm; whereas, files have one and
How to Use
The reamer is used with pushing and rotating motion.
Reaming involves placement of instrument towards
apex until some binding is felt and then revolving the
handle clockwise. Clockwise turning will remove
dentin chips and debris from the canal wall; however,
counter-clockwise turning may force the same apically.
Flexoreamer, a modified version of reamer, is usually
used in curved canals. Flexoreamer has non-cutting tip.
It is distinguished from the normal reamer by having

Table 11.3 Differences between broach and rasp

Broach Rasp
Taper is 0.007–0.01 mm/mm Taper is 0.015–0.02 mm/mm
Usual barb height is half the Usual barb height is one-third
core diameter (other sizes the core diameter
available)
Barbs are deep and sharp Barbs are shallow and round Fig. 11.10 Symbols on the handle of files: a. H-file (round);

11 Weaker as compared to rasp Stronger as compared to

broach
b. Reamer (triangular); c. K-file (square); d. K-flexo file
(square with same color of size code); e. Ni-Ti file (square
with half colored)

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 Endodontic Instruments 157

half to two and a half flutes per mm and thus having moved slightly mesially; then, towards the lingual
many more cutting edges. The cross-sectional area of aspect and finally to the distal. This is known as
file (from one angle to opposite angle in the blank) is ‘circumferential filing’.
greater than that of reamer, making it less susceptible It is established that the instrument, rather than its
to breakage. The greater cross-sectional diameter of file use, determines the general shape of canal preparation.
decreases its flexibility. Therefore, reaming action produces a canal that is
The progressive taper may enhance the cutting action relatively round in shape; whereas, filing action may
while decreasing rotational friction between blade of produce irregular and eccentric canal shape. Smaller
the file and the dentin. size files (up to number 20) have sufficient flexibility to
The non-cutting tip design allows each instrument retain canal shape. However, larger files, being not
to safely follow the secured portion in the canal, while flexible, may alter the canal shape.
small flat area on the tip enhances its ability to find its Flexofiles, a modified version of files, is usually used
way through soft tissue and debris. for curved canals. Flexofile has non-cutting tip. It is
The differences between reamers and files are distinguished from the normal file by having different
summarized in Table 11.4. color of the number on top of the handle (Fig. 11.11);
for example, in size 30 file, ‘30’ is written in white color
How to Use on top of the handle; whereas, in flexofile, ‘30’ is written
The file is used with pulling motion. Filing involves in blue color on top of the handle.
placement of instrument in the root canal until some
binding is felt. The instrument is removed by scrapping iii. Hedstrom Files
against the side wall with little or no revolution. The Hedstrom files are identified by the ‘circle’ symbol on
dragging against one side of the wall is also referred to the handle. These files were manufactured with the idea
as rasping action. The withdrawal of instrument by of having superior cutting efficiency. These files have
dragging the flutes on dentin walls effectively prepares flutes that resemble successively smaller triangles set
the canal. on one another (Fig. 11.12). They are manufactured by
‘Pistoning’ the file (moving up and down) forcefully using sharp rotating cutter that gouges triangular
in the canal should be avoided. This motion tends to segments out of a round shaft. This produces sharp
pack dentinal filings at the apex and may create ledges, cutting edges at the base of each cone, which cut tooth
etc.
The instrument should preferably be moved first
towards the buccal side of canal, then reinserted and

Table 11.4 Differences between reamers and files

Reamers Files
• Made from triangular blank • Made from square blank
of wire of wire
• Number of flutes are 1–1½ • Number of flutes are 1–2½
per mm per mm
• Cutting angle is 60° (sharp • Cutting angle is 90° (less
cutting) sharp cutting)
• Used with reaming motion • Can be used with reaming
and rasping motion
• Chip space is 60% (more • Chip space is 36% (does
clearing space) not allow much removal of
loosened material: less
clearing space)
• Produce canal round in • Produce canal irregular in
shape shape
• Less efficient
• More flexible
• More efficient
• Less flexible
Fig. 11.11 K-flexo file (right): Blue color code on top of
handle; K-file (left): White color code on top of handle
11

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 158 Essentials of Endodontics

i. Modification in Instrument Design

• Flex-R file: The square cross-section of file was
modified to triangular cross-section. The modified
form provides advantages such as, increase in cutting
efficiency, increase in flexibility and holding more
debris. The tip is flattened, i.e. non-cutting tip. The
non-cutting tip decreases the chances of canal
transportation and ledging during enlarging curved
canals.
• K-flex file: The square cross-section of the K-file is
changed to rhomboid cross-section. The cutting edge
is formed of two acute angles and two obtuse angles.
The acute angle increases sharpness, whereas obtuse
Fig. 11.12 Apical end of H-file angle provides more space for debris removal. The
overall flexibility is also increased.
structure on pulling only. The cross-section of H-file • S-file/Uni-file: A second blade is added to the single
shows coma-shaped (tear drop) appearance with one blade of the H-file. A third blade addition (Helifile)
cutting edge. As the cutting efficiency is increased, the is also tried. These files are more aggressive in cutting
efficiency; however, flexibility is poor. The decreased
flexibility is compromised (flexibility is minimum).
depth of S-file/Uni-file significantly decreases the
Indications tendency of these files to break inside the canal.
• U-file: The U-file has two 90° cutting edges at each
• Instrumentation of immature teeth with wide canals,
of the three points of the blade. The flat cutting
which may harbor considerable debris.
surface, referred to as ‘radial’, allow instrument to
• To remove silver points or loose broken instruments be used in 360° motion.
from canals. The file is placed alongside the • Canal master file: The cutting segment of the
instrument, rotated and pulled occlusally. instrument is reduced from 16 to 1.0–3.0 mm. Such
• To widen coronal portion of curved canals. reduction in cutting segment reduce the chance of
• For widening the orifices of any canals for easy canal transportation and ledging during enlargement
manipulation during preparation and obturation. of the curved canals.
• C-files: These files are ideally suited for sharply
Drawbacks curved or calcified canals. These are available in ISO
• Gouging in the root canal may lead to fracture if bind sizes 8, 10 and 15 with lengths of 18, 21 and 25 mm.
in dentin (only ‘pull’ stroke is allowed; rotation lead The files are of stainless steel, having a square cross-
to fracture). section and a blunt, non-aggressive tip, which allow
• If screwed apically with force, the susceptibility of the instrument to safely follow the canal to the apex
root fracture increases. (Fig. 11.13).
R-file (Rat-tail file), though not commonly used, is
similar to barbed broach having metal projections
perpendicular to the instrument shaft with pointed
polyhedron cross-section. The file fracture easily during
working, so not used in routine.

Modification in Files
The initial designs could not clean and shape the entire
canal space while retaining the preoperative shape of
the canal. The modifications in file system are:
i. Modification in instrument design
ii. Modification in numbering system
11 iii. Modification in method of manufacturing
iv. Modification in instrument material Fig. 11.13 C-file

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 Endodontic Instruments 159

• Path finder files: The smaller number K files (K6 and is recommended in those canals, which need
K8) are used to negotiate the patency of root canals, intermediary file sizes.
known as ‘path finders’. Profinder system provides • Series 29: Another file system is ‘Series 29’, whereby
files numbering 10, 13 and 17. instead of increasing each small file by 0.05 mm
• Triple-flex files: The Triple-flex file is obtained by between sizes, it should be increased by 29%
twisting a steel wire with triangular cross-section. (Schilder named it as Profile 29 series). Let us keep
Triangular design offers exceptional flexibility and file number 10 as a key size. The file smaller than it
efficient cutting ability. The Triple-flex file is would be 0.071 mm at D0 and file larger would be
available in ISO sizes from 08 to 80 and lengths 0.129 mm at D0. This system works well in small
21, 25 and 31 mm. sizes; however, in larger sizes this much increase was
not possible. The system provides two advantages: first
ii. Modification in Numbering System constant increase in instrument diameter and second,
• Intermediate size files: Many a times, the standard size it provides fewer number of instruments as
of the file is to be modified as per requirement of the compared to ISO system.
operator. 1.0 mm apical cutting of the file number
10 makes it number 12 file and size 15 becomes size iii. Modification in Method of Manufacturing
17 (Fig. 11.14). Such files are made available in sizes Instead of instrument twisting, the flutes are created
of 12, 17, 22, 27 and so on. Later, these odd number by grinding or milling to decrease the internal stresses
files were manufactured so that, the operator did not induced in the instrument during twisting process.
have to clip the file. The drawback in this file system Later computer assisted milling technique provided
is that every file may not be, exactly of the standard files with sharper flutes and also deeper spaces between
size, since a deviation of 0.02 mm is acceptable. the flutes.
Therefore, a size no. 10 instrument may be as small • Flex-R file: These files are manufactured following
as 0.08 or as large as 0.12 mm. This explains why the computer assisted milling technique. The flutes are
operator may have difficulty moving from one size sharper and the tip is rounded.
to next size, especially in narrow/curved canals. • Ultra-flex file: These files are also manufactured
• Golden mediums: The files are identical to the K- following computer assisted milling technique using
Flexofiles, except that they have intermediate sizes Ni-Ti alloy. The flutes are less sharp than Flex-R file.
as compared to ISO standard sizes. The files are pre- • Sure-flex file: Similar to ultra flex with sharper
sterilized with color-coded, plastic handle. They are flutes.
only available in sizes 12, 17, 22, 27, 32 and 37;
the lengths remain 21, 25 and 31 mm. Their use iv. Modification in Instrument Material
Initial instruments were fabricated from carbon
steel; however, due to decreased flexibility and low
corrosion resistance of carbon steel, instruments were
fabricated in stainless steel. Path finder is the only
instrument that is still manufactured from carbon
steel. The poor flexibility of stainless steel led to the
advent of Ni-Ti instruments. Ni-Ti instruments
offer better flexibility; however, its cutting ability is
compromised.

E. OBTURATING INSTRUMENTS
i. Spreaders and Pluggers
Spreaders and pluggers are used for root canal
obturation. Spreaders are designed for lateral conden-
sation, while pluggers are for vertical condensation.
They are made of stainless steel or chromium plated

Fig. 11.14 Modification of instrument

brass and generally have long handle. These instru-
ments can either be of a uniangular or bayonet style.
Root canal spreaders are usually of the bayonet style.
11

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 160 Essentials of Endodontics

The instrument with long handles are potentially • Spreader dryer: The spreader dryer has a metal heat
dangerous, because the tips of the working ends are retention bulb for longer working time. It is made of
offset from the long-axes of the handles. This may result stainless steel and available in sizes #2(30), #3(40) and
in strong lateral wedging forces on the working end if #5(50). The vertical and lateral condensation in warm
the instrument is not operated carefully. gutta-percha technique is better performed using
Finger Pluggers and Finger Spreaders were these spreaders.
introduced having small handle (Fig. 11.15). These
• Roeko spreader and plugger: Roeko spreaders are
are manufactured both in Ni-Ti and stainless steel.
available in stainless steel (size 20 to 50) and Ni-Ti
These are available in ISO sizes 15 to 80. The length
(size 15–35) having rings on the handle, which
is 21 mm and 25 mm and the taper is 2%. Pluggers
signifies their size. The flexible tips of Ni-Ti spreaders
have flat tip, whereas spreaders have sharp tip
(Fig. 11.16). facilitate lateral condensation of gutta-percha even
in curved canals. The spreaders have mm length
Modifications graduation on the tip.
• Heat carriers and pluggers: The heat carrier and • M-series pluggers and spreaders: The M-series is the
pluggers are designed exclusively for the warm first calibrated plugger and spreader system sized
vertical gutta-percha technique. These are machined to match standard ISO files and gutta-percha points.
from a special stainless steel and are angled inward The ISO-sizing and tapering virtually eliminate
for easy insertion. They are available in anterior and binding and allow deeper penetration for better
posterior configurations to allow for easier access. apical seal. The ISO color-coded instruments are
available in either a single-ended or double-ended
spreader/plugger combination.

ii. Paste Fillers (Lentulo Spiral)

The routinely used paste filler is Lentulo spiral,
which is available in three lengths, 17, 21 and 25 mm
with size 15–40. The metal handle is color coded. Both
hand and rotary versions are available (Fig. 11.17).
The modified version of paste filler has also been
introduced, viz. DYNA (length 21, 25 mm; size 25–40),
Medidenta (length 21, 25 mm; size 25–70), Sensipast
(length 21 mm; size 25–40) and Roydent (length 21 mm
and 25 mm; size 25–40). Short length (18 mm) paste
fillers are also available.
Fig. 11.15 Spreaders

11 Fig. 11.16 Spreader (top) and plugger (bottom) Fig. 11.17 Lentulo spiral

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 Endodontic Instruments 161

Automated Devices handpiece also has a quarter-turn reciprocating

Automated devices are the instruments which revolve motion along with a vertical stroke.
fully/partially or reciprocate around an axis and work
1. Reciprocating Instruments
under higher speeds.
a. Giromatic
Advantages
• Significantly quicker Girofiles and Girobroaches are used along with
Giromatic handpiece (Fig. 11.18a and b). The handpiece
• Canal shape is smooth, well-centered
is designed to rotate the instrument a quarter-turn in an
• Better removal of smear layer alternate direction. The root canal instruments are
• Less debris extruded apically activated in the root canal at a speed of up to 3000
• Less operators’ fatigue. cycles/minute. Manufacturers claim that the working
Disadvantages is fast with Giromatic; however, studies could not
observe much difference between Giromatic and the
• Lack of tactile sensation
hand files. The loss of tactile sensation, as with other
• Susceptible of perforation/ledges, etc.
power driven handpieces, may lead to zipping, over
• Susceptible of file breakage. instrumentation and even breakage of the instrument.
The automated devices are categorized into three M4 safety handpiece and Endo-grapper are modified
variants: versions of Giromatic handpiece.
1. Reciprocating: Imparts partial rotation and/or back
and forth movement to cutting instruments
(Giromatic, Canal finder system/Endo pulse, etc.)
2. Vibratory: The instrument vibrates in the canal
[Ultrasonic (Cavi Endo) and Sonic ( MM 1500)]
3. Rotary: Provides continuous rotation of cutting
instruments at a fixed speed (Profile, Light speed,
RaCe, etc.)
The rotation/reciprocation is carried out with the
help of another gadget known as ‘Handpiece’. The
handpiece gets rotational energy from engine driven
motors. Three types of contra-angle handpiece are
usually used, viz. (i) a full rotary handpiece either latch
or friction grip; (ii) a reciprocating/quarter-turn Fig. 11.18a Giromatic handpiece
handpiece and (iii) special handpiece that imparts a
vertical stroke along with reciprocating quarter-turn.
i. A full rotary handpiece allows straight line drilling
and/or side cutting. The burs or diamond points
used with full rotary contra-angle handpieces can
be used to achieve coronal access.
ii. A reciprocating handpiece provides quarter-turn
to the instrument. It accepts only latch type
instruments. Recently, M4 Safety handpiece having
300 reciprocating motions has been introduced. It
has unique chuck that locks regular hand files in
place by their handle. Safety Hedstrom instruments
are recommended to be used with M4 handpiece.
The Endo-grapper is a similar handpiece, with a
10:1 gear ratio and a 450 turning motion.
iii. A vertical stroke handpiece (canal finder) delivers
a vertical stroke ranging from 0.3–1.0 mm. The
depth of vertical stroke depends upon the free
movement of the instrument in the canal. The Fig. 11.18b Girofiles
11

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 162 Essentials of Endodontics

b. Canal Finder System/Endo Pulse motion or upward brushing stroke against the canal
The canal finder system utilizes handpiece, which runs walls. The preparation is completed following Endo-
the instrument in a 0.4 mm up and down motion with Eze files in sequence. Continuous irrigation and
an additional full turn movement when pressure is recapitulation is mandatory.
applied. The handpiece offers continued irrigation to • The apical one-third is prepared using Ni-Ti
flush out dentinal chips and can be operated in a wide transitional files. The apical preparation is completed
range of reciprocal speeds. with hand Ni-Ti files, usually three to four sizes
The file used with canal finder system is A-file. The larger than the initial apical instrument.
file has 40° helical angle; which provides efficient Advantages
cutting. It has non-cutting tip; allows the file to follow • Simple and reliable.
the canal lumen without encroaching the outer walls.
• Anatomical variations and pathological conditions
The tip is longer and more rounded than traditional
seldom affect its results.
files. The canal finder system is used for other purposes
• Hybridization concept uses technology and rapidity
also, such as, root canal obturation, removal of broken
of the systems; maximizing the traditional nature of
instruments, etc.
hand instrumentation.
The vertical reciprocation has the following
• Non-circular instrumentation and ability to adapt/
advantages:
follow the natural anatomy of coronal and middle-
• Reduction of file separation
third of the canal length virtually eliminates the
• Ni-Ti files are not required (stainless steel files are used) complications like ledging, zipping, canal transpor-
• Elimination of file torque strain. tation, unnecessary tooth structure removal and file
separation, etc.
c. Endo-Eze System
• Because of small tip diameter of the active portion,
Endo-Eze system is a hybridized system designed for the files are very much flexible and permit
the preparation of curved, ribbon-shaped or flattened instrumentation without deviations, especially in
canals along with the straight canals. The system curved canals.
combines the benefit of stainless steel and Ni-Ti
instruments. These files are used in reciprocating/ d. EZ-Fill Safesider
oscillating motion in each direction. The hybridization These are series of non-circular instruments having a
system combines the merits of both hand instruments flat side, which extends the entire length of cutting edge.
and rotary instruments along with the merits of Ni-Ti These are available as a file or reamer (length 21 and
files and stainless steel files. 25 mm), both for manual and reciprocating (Endoexpress
The system consists of the following: handpiece) use. Both stainless steel (size 08 to 40) and
• Three stainless steel shaping files, viz. Purple (10/02), Ni-Ti (30/04: Orange, 25/08: Brown and 25/06: Pink)
white (13/03) and yellow (13/04) with respective size variants are available. The size, taper, make and color
and taper. are tabulated in Table 11.5.
• Three Ni-Ti transitional files (25 mm and tapers 0.08,
0.04 and 0.02) and two hand K-type stainless steel
Table 11.5 Size, make, color and taper of EZ-Fill Safesiders
files (size 15 and 20) are also provided.
• Endo-Eze contra-angle handpiece, reciprocating at Size Make Color Taper
30° with 4:1 reduction motor at the speed of 5000 rpm. 08 SS Grey 02
10 SS Purple 02
Technique
15 SS White 02
• The glide path is achieved with stainless steel file,
followed by Ni-Ti files, especially in curved apical 20 SS Yellow 02
areas. 25 SS Red 02
• Working length is determined using small number 30 SS Blue 02
hand files. 35 SS Green 02
• The first instrument (apical instrument) that feels 40 SS Black 02
resistance at the working length is determined. Once 30 Ni-Ti Orange 04

11 the canal is negotiated, mechanical reciprocating

instrumentation is begun using Endo-Eze handpiece.
The reciprocating shaping files are used in a circular
25
25
Ni-Ti
Ni-Ti
Pink
Brown
06
08

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 Endodontic Instruments 163

The flat surface makes the instrument easy to use, This causes breaking of cells leading to their destruc-
prevents accumulation of debris, reduces stress and tion. The broken cell parts are washed out and removed
increases the flexibility of the instrument. from the canal system.
With this system, coronal one-third of canal is shaped Removal of dentin for canal preparation and
with peeso reamers leaving the apical one-third for elimination of unwanted intracanal materials is
Safesiders and hand files. A peeso reamer called accomplished in less time and with better efficiency
‘Pleezer’ (size 2 of peeso reamer) is provided, which with ultrasonic files (Fig. 11.19) as compared to hand
straighten the coronal curves of the canal more easily files. Ultrasonic endodontics is particularly effective for
and with less resistance. larger canals and canals that are interconnected.
Ultrasonic tips have been broadly classified as
Significance of flat surface
follows:
• Flat surface reduces the amount of cutting surface
in contact with the canal wall. It may decrease the a. Non-surgical
efficiency for time being, but the manipulation is • Access refinement tips (used for access preparation
much easier and with less fatigue. and refinement)
• Dentin debris created can be removed easily. • Vibratory tips (used to remove post and core)
• Because less instrument is cutting at any time, less • Bulk removal tips (remove dentin and core
stress is given to the instrument; subsequently, less material quickly)
chances of breakage. • Troughing tips (used for instrument retrieval)
• Increases the flexibility of the instrument. b. Surgical
• Surgical retro-tips (used for root end preparation).
2. Vibratory Instruments The most frequently used ultrasonic electromagnetic
a. Ultrasonic unit is ‘Cavi-endo’. For dental use, piezoelectric units
are much more powerful than electromagnetic units.
The endodontic treatment by ultrasonic, sonic or
They are effective in removing silver points and posts
subsonic systems is termed ‘Endosonic’. The equipment
from root canal space. The most frequently used
creates a synergistic system, whereby canal preparation
piezoelectric unit is ‘Enac’.
cleaning, irrigation, disinfection, and filling are all
accomplished with the same device. An ultrasonic Removal of smear layer may be accomplished more
device converts electrical energy into ultrasonic waves readily with ultrasonics, but site where the tip actually
of certain frequency by magnetostriction and by touches the canal wall produces a new smear layer. It
Piezoelectricity. is suggested that ultrasonic device should be used after
Ultrasonic endodontics is based on a system in which canal preparation by hand and the file should remain
sound as an energy source at 20–25 kHz activates an in the center of canal away from walls. File must be
endodontic file, resulting in three-dimensional small and loose in canal, particularly in curved canals,
activation of the file in the surrounding medium. to achieve optimum cleaning.
The ultrasonic devices derive energy from instru-
ments vibrating and using either electromagnetic or
piezoelectric power sources. Magnetostriction is
generated by deformation of ferromagnetic material
subjected to a magnetic field; whereas, piezoelectricity
is the generation of stress in dielectric crystals subjected
to an applied voltage. Magnetostrictive transducers
produce an elliptical motion at the working tip, while
piezoelectric transducer produces longitudinal or
transverse linear motions.
Method of action: Ultrasonic cleaning was described
initially as implosion or cavitation. Cavitation occurs
when ultrasonic file vibrates in a liquid to produce
alternate compressions and rarefactions of pressure. A
negative pressure develops within the exposed cells of
intracanal materials (pulp tissue, bacteria, debris, etc.). Fig. 11.19 Ultrasonic files
11

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 164 Essentials of Endodontics

Sonic handpieces: The sonic endodontic handpiece diamond, which allows access into the pulp chamber
available is Micromega 1500 (or 1400). Like air rotor and also prepares the chamber walls (Fig. 11.20).
handpiece, it attaches to regular airline at a specified
air pressure. The air pressure may be raised with an Endo-Z bur: It is a long, tapered bur for easy access in
adjustable ring on the handpiece to give an oscillatory pulp chamber after initial preparation. It has a non-
range of 1500–3000 cycles per second. The irrigant/ cutting safe tip, which prevents its penetration in the
coolant is delivered into preparation site from the pulp chamber. The cutting surface length is 9.0 mm and
handpiece. The three types of files that are used with total length is 21 mm (Fig. 11.21).
Micromega 1500 are Heliosonic, Shaper and Rispisonic. Munce Discovery bur: It has long, narrow, stiffer shaft
The Shaper and Rispisonic are barbed while Heliosonic design (Fig. 11.22) for better visibility, reduced
has a fluted cutting edge. The Heliosonic and Shaper
impingement on deep walls and positive troughing
files are numbered 15–40; whereas, Rispisonic files are
control (34 mm for deep troughing and 31 mm for
numbered 1–6. All these instruments have safe ended
shallow troughing). It is available in 6 head sizes (#¼,
non-cutting tips.
#½, #1, #2, #3, #4).
Sonic instruments produce an elliptical pattern of
transverse oscillation when operated in air, a pattern LN bur: It is a unique ½ round bur on a long neck (length
similar to those powered ultrasonically (magneto- 28 mm). Its design allows for deep drilling along side
strictive). However, this large transverse motion is post or broken instruments (Fig. 11.23).
eliminated entirely and replaced by a true longitudinal
vibration of the file, when the file is activated and
loaded in the canal.
Ultrasonic and sonic instruments are similar in
design in that they consist of a driver onto which
endosonic file is clamped. The oscillatory pattern of the
driver determines the nature of movement of the
attached file. Although, the main driver oscillates
longitudinally, the file vibrates transversely. This sets
up a characteristic pattern of nodes and antinodes.
Ultrasonic files of varying lengths are available to be
used with the ultrasonic unit.

3. Rotary Instruments
Rotary instruments are constantly rotated at a fixed
speed. They require another gadget known as hand- Fig. 11.20 Endo Access bur
piece for carrying the rotation. The rotary instrument
can mainly be divided into two categories.
I. Instruments used for access cavity/coronal
preparation
The following instruments are commonly used for
access cavity/coronal preparation: Fig. 11.21 Endo-Z bur

a. Burs
Conventional burs are used initially for access cavity
preparation. Long shank burs and extra long shank burs
are used in endodontics during preparation of deep
pulp chamber and even preparation of coronal pulp
spaces. These burs can also be used to remove the gutta-
percha from the coronal aspect of the root canal.

11
The modified burs used in endodontics are:
Endo Access bur: A specially designed bur ‘Endo Access
Bur’, is a combination of round and cone-shaped coarse Fig. 11.22 Munce Discovery bur

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 Endodontic Instruments 165

Fig. 11.23 LN bur

Fig. 11.24 Transmetal bur

Transmetal Bur: It is an extra fine cross-cut shape bur,

which is designed to remove an old amalgam filling or Fig. 11.26 Peeso Reamer
to cut through metal/metal fused to porcelain crowns
without shattering the porcelain or breaking the bur.
The cutting surface is 5.0 mm and total length is 19 mm
(Fig. 11.24).

b. Gates Glidden (GG) Drills

Gates Glidden drills are made of stainless steel and are
available in two sizes, viz. short (28 mm) and regular
(32 mm). They are number 1–6 (Fig. 11.25). The number
on both the Gates and Peeso are denoted by the number
of circumferential grooves located on the shaft just
below the cut-out for the latch. The Gates Glidden drill
is used to expand the canal orifice for easier instrumen-
tation and obturation. It may be used to expand the
coronal portion of root canals. Judicious use of the
instrument is mandatory, since, it is liable to fracture.

c. Peeso Reamers
The make and number of the Peeso Reamers are same
as that of Gates Glidden drill (flute length 8.5–9.0 mm).
Fig. 11.27 Gates Glidden drill (right) has smaller head than
Peeso reamer is stiff instrument and does not follow peeso reamer (left)
root canal even if there is slight curvature. Its main use
is to prepare the root canal for post and core preparation
because of its effective lateral cutting. The recommended speed is 400–800 rpm. Gates Glidden drill and Peeso
reamers are not end-cutting instruments (by definition
they should be reamers and not drills). There is a nipple
at the end of these instruments, which prevents cutting
at the tip. When the nipple engages the wall of a curved
canal, the drill just spins and does not cut apically
(Fig. 11.26).
The differences between Gates Glidden drills and
Peeso reamers are:
i. Cutting head is much smaller on Gates Glidden drill
as compared to Peeso reamers (Fig. 11.27)
ii. The shaft is thinner on Gates Glidden drill
iii. The diameter of heads are different for the same

Fig. 11.25 Gates Glidden drills

number instrument (Table 11.6) (Peeso reamer
number 2 and Gates glidden drill number 3 are
equivalent to size 90 files)
11

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 166 Essentials of Endodontics

Difference of sizes of Gates glidden drill and

Table 11.6
Peeso Reamer
Size No. Gates glidden drill (mm) Peeso Reamer (mm)
1 0.5 0.7
2 0.7 0.9
3 0.9 1.1
4 1.1 1.3
5 1.3 1.5
6 1.5 1.7

II. Instruments used for root canal preparation

There are numerous rotary systems currently being
used for preparation of root canals. Some systems also
provide irrigation and obturation facility. The main are:

a. Profile System Fig. 11.28 Profile system

Profile instruments, available both in stainless steel and
Ni-Ti are the first product of Series 29 (Table 11.7). • It has 20° negative rake angle at cutting edge. The
Initially hand instruments with 0.02 taper were non-cutting tip guides the instrument into canal.
marketed. Later, rotary instruments with 0.02 taper and
Clinical Performance
also with 0.04 and 0.06 taper were developed (Fig. 11. 28).
The size varies from 2 (0.129) to 10 (1.0 mm). The greater The clinical performance of the instrument is based on
taper instruments were designated as ‘orifice shaper’. following features, viz. cutting efficiency, shaping
Later, a series of greater taper files having 0.06, 0.08, ability, cleaning efficacy and effect of sodium hypo-
0.10 and 0.12 taper were designed, which provide chlorite.
continuous shape and requisite flare in the coronal one- i. Cutting efficiency: Cutting efficiency has been
third area. defined as ‘the procedure of removal of simulated canal/
The characteristic features are: tooth structure with fluted instrument’.
• The cross-sectional geometry is created by machining The profile system has passive cutting blades. The
three equally spaced U-shaped grooves around the slight negative rake angle and radial lands make
shaft of a tapered Ni-Ti wire. file cut less aggressively than those having active
• It has symmetric radial lands, which allow file to cutting blades (Protaper, Hero 642, RaCe and POW-
remain self-centered in the canal. R) and those having semi-active cutting blades
• There is a central parallel core that may account for (Quantec).
enhanced flexibility compared with ‘Quantec’ and ii. Shaping ability: It is established that the Ni-Ti rotary
‘Protaper’, which possesses a tapered central core. files stay centered and maintain canal curvature
better than stainless steel hand files.
Canal shaping with profile usually result in a
Table 11.7 Series 29 instruments
round preparation and smear layer formation. It is
Number Size (mm) Color code shown that about 35–40% of canal surface remains
2 0.129 Silver untouched after complete instrumentation.
3 0.167 Gold iii. Cleaning efficiency: The cleaning efficiency is
4 0.216 Red comparable to hand files. The profile ‘Series 29’ files
5 0.279 Blue can be effective up to 70%, if used along with
6 0.360 Green irrigant.
7 0.465 Brown iv. Effect of sodium hypochlorite: Sodium hypochlorite
8 0.600 Silver irrigation may corrode the Ni-Ti instrument.

11 9
10
0.775
1.000
Orange
Red
The micropitting on instrument surface may
lead to areas of stress concentration and crack
formation.

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 Endodontic Instruments 167

Technique
The recommended sequence of use of profile
instruments is as follows:
• Estimate working length of the canal.
• Create a glide path with a size 10–15 stainless steel
K-files.
• Use appropriate sized ‘Orifice Shapers’ in coronal one-
third.
• Prepare root canal following crown-down technique
[use profile instrument (taper/size) of 0.06/30, 0.06/
25, 0.04/30 and 0.04/25 up to the resistance].
• Perform apical preparation with taper/size of 0.04/
25 and 0.04/30.
• Finish with taper/size (0.06/25) short of working
Fig. 11.30 Rotary protaper
length, blending middle and apical portion.

b. Protaper System Shaping file S1 has a purple identification ring and

S2 has a white ring. The diameter at tip of S1 is
The Protaper system provided less number of files. The
0.19 mm and of S2 is 0.20 mm. Both instruments have
number of files with a progressive taper (Protaper) was
an increasing taper over whole working range,
decreased to a set of six instruments: three shaping files
although the increase is not as aggressive as that of SX.
for crown-down procedure and three finishing files
S1 is designed to shape mainly in coronal section of
for apical shaping. They are available as both hand
root canal and S2 for middle section.
(Fig. 11.29) and rotary files (Fig. 11.30).
The three shaping files are characterized by The finishing files F1, F2 and F3 are marked with
increasing taper over the whole length of their cutting a yellow, red and blue ring respectively. Their
blades. The finishing files are available in different dimensions at D 0 are 0.20, 0.25 and 0.30 mm
diameters and a fixed taper over 3.0 mm to finish apical respectively.
preparation. The characteristic features are:
The file design provides ideal and efficient shaping • The convex triangular cross-section reduces the
of coronal aspects of root canal. contact area between blade of file and dentin, and
The first file of Protaper system is called shaper X or serves to enhance the cutting action and improve
SX. It lacks identification ring and is given gold colored safety by decreasing the torsional load.
handle. SX is available with cutting blade of 14 mm • These files have a continuously changing helical
and a tip diameter of 0.19 mm. angle and pitch over 14 mm of cutting blades. This
effectively allows its blades to auger debris out of
canal and prevents the instruments from inadvertently
screwing into the canals.
• The shaping files have progressively tapered design
which clinically improves flexibility and cutting
efficiency.
• Increasing D 0 diameter and percentage taper
correspondingly increases the stiffness of the
instrument.
• All protaper shaping files have a progressively
increasing taper; SX has the highest increase. At D6,
D7, D8 and D9 the cross-sectional diameter increases
from 0.50, 0.70, 0.90 and 1.10 mm respectively. The
total increase of taper in SX from D0 to D9 is nine

Fig. 11.29 Hand protaper

different tapers from 3.5 to 19%. S1 has an increasing
taper from 2% on D 1 to 11% on D 14. S2 has an
increasing taper from 4% on D1 to 11.5% on D14.
11

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 168 Essentials of Endodontics

• The three finishing files have a fixed taper in first

3.0 mm from D0 to D3. (F1 7%, taper F2 8% taper and
F3 of 9% taper. The remaining length of cutting blade
has the reverse taper. The decreasing taper ensures
a continuing flexibility within a file. The instruments
provide better apical preparation in addition to
shaping middle section also.
• The modified tip allows the instrument to follow the
canal and find its way through loose tissues without
damaging root canal walls.
• Protaper files have short (1.25 mm) handles as
compared to other standard files (1.5 mm). Short
handle serves to improve access into posterior
regions.

Technique
• Initially 10 or 15 size hand file is used to negotiate Fig. 11.31 Light speed instruments
the patency of the canal. The working length is
established following routine procedures. • The cutting heads are 0.25 mm (size 20) and 2.25 mm
• Coronal shaping is carried out with SX file. If a light (size 40) long. Light speed is only rotary system
resistance is felt, the file is withdrawn and worked whose cutting heads have three different geometric
in a brushing motion against the root canal walls. shapes. The first five light speed instruments have
• S2 file is inserted preparing the middle half of the short, non-cutting pilot tip and 75° cutting angle. The
root canal. It can be used for apical preparation also. size 32.5 instrument has a slightly longer non-cutting
Apical preparation is carried out with finishing pilot tip and 33° cutting angle. All other instruments
files. have longer non-cutting pilot tips and a 21° cutting
• A uniform taper of 7% is produced in apical portion angle.
of canal using finishing files. The apical diameter of • The instruments have thin, taperless, non-cutting
root canal is gauged with size 20 K-file. The shafts (this design maximizes flexibility and enables
instrument is inserted passively into the canal to the instrument to negotiate curves.)
working length. If the file binds in apical region, • The shank is marked with rings that indicate distances
preparation is completed. If file is loose, F2 is used from the instrument’s tip. For 21 and 25 mm instru-
up to working length. ments, junction of shaft and shank is 18 mm from tip
Protaper can be helpful in retreatment cases; and for 31 mm instrument, distance is 22 mm.
finishing files are useful in complete removal of gutta- • 21 mm instruments have only one ring in shank
percha. (20 mm from tip) and 25 mm instruments have three
rings indicating distance of 20, 22 and 24 mm from
c. Light Speed (LSX) System tip. In contrast, 31 mm instruments have four rings
The light speed instruments are available in different indicating distance of 24, 26 and 28 and 30 from tip
sizes (size varies from 20 to 140). In between sizes such junctions.
as 22.5, 27.5 and 32.5 respectively between 20 and 25, The differences in light speed and conventional hand
25 and 30 and between 30 and 35 and so on are also files are tabulated in Table 11.8.
available. The half sizes are color coded exactly as
previous size along with white or black markings or Technique
engraved rings on instrument handles (Fig. 11.31). The Light speed instruments require a straight line access
instruments are available in three lengths, viz. 21, 25 to mid-root areas. The root canal walls are shaped using
and 31 mm. H-files, which facilitate rotating instruments unhindered
The characteristic features are: to mid-root area. The working length should be recorded
using small sized K-files.
11 • Light speed cutting heads are short and have three
radial lands and three U-shaped special grooves
between radial lands.
Once a light speed instrument has reached its desired
length, do not linger at that point and immediately

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 Endodontic Instruments 169

Table 11.8 Differences in light speed and conventional hand files

Light speed instrument Conventional hand files
Metal/alloy Ni-Ti Stainless steel
Length of cutting head 0.25 to 2.25 mm 16 mm
Tip angles Varies 21, 33 and 75° Similar for all files
Non-cutting pilot tip Present Absent
Intermediate sizes Available Not available
Minimum size 20 08
Maximum size 140 140

withdraw the rotating instrument from the canal. Step 4. Recapitulation: The canal is recapitulated using
Sequence of instrument is important as for other respective master apical instrument to working
techniques. length.
There are three methods of using light speed
instruments: ii. Zurich technique
i. Conventional technique The steps followed in this technique are:
ii. Zurich technique
Step 1. Coronal pre-flaring: After canal orifices are
iii. Hybrid technique located, their coronal openings are enlarged using Gates
i. Conventional technique glidden drills. Initially, 4.0–6.0 mm coronal flaring is
The conventional technique involves four steps: achieved.
Step 1. Determining initial light speed size: A light sped Step 2. Determining initial apical instrument: Working
instrument can reach working length if its cutting head length is determined using size 15 stainless steel K-files.
is smaller than canal’s diameter at the constriction. For Then light speed instruments are used. The first few
example, size 25 light speed instrument if reaches light speed instruments may not bind within the canal.
working length indicates that canal’s diameter is larger The instrument which first feels resistance in the canal
than size 25. Gauging continues with sequentially larger is termed ‘Initial apical instrument’.
sizes until a light speed instrument does not reach
working length. If size 25 reaches working length but Step 3. Determining master apical instrument: All light
size 27.5 does not, then size 27.5 is termed ‘first light speed instruments used after initial apical instruments
speed instrument’. are called ‘binding instruments’. They are used with
controlled forward (1.0–2.0 mm) and backward (2.0–
Step 2. Determine master apical size: After determining
4.0 mm) ‘pecking movement’. The forward motion reams
the first light speed instrument size, appropriate size
the canal; whereas, backward motion tends to clean as
of instrument required for apical preparation is
it retreats into fresh irrigant. These instruments are used
determined. The instrument that takes at least 12 pecks
sequentially from smaller to large size. The last
to reach working length is ‘master apical instrument’.
instrument used to prepare apical area (may be 6–12
This is known as “12 Pecks Rule”.
light speed instruments larger than the initial
Step 3. Complete apical instrumentation: After determining instrument) termed ‘Master apical instrument’.
master apical instrument size, complete the apical
preparation by using next light speed size that is Step 4. Step back and recapitulation: After master apical
4.0 mm shorter than working length. If obturating with instrument is finalized, the step back preparation is
standard gutta-percha cones, step-back 4.0 mm with initiated. The last step-back instrument is termed ‘Final
sequentially larger light speed instrument so that each instrument’.
length is 1.0 mm shorter than previous instrument. This Finally, the canal is recapitulated using respective
prepares the apical 5.0 mm of canal with a taper master apical instrument to working length.
matching that of a standardized cone. Half size
instrumentation is also carried out in routine. iii. Hybrid technique
If master apical size is 40, step back in 1.0 mm
increment to at least size 65 (25 plus initial master apical
size).
As the name indicates, initial preparation is carried out
with hand instruments and final preparation with light
speed ones.
11

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 170 Essentials of Endodontics

d. Quantec System Technique

The Quantec system provides graduated taper • Crown-down technique is followed in routine.
technique, whereby a series of varying tapers are used • Half of the working length is prepared using 0.06
to prepare a single canal. The instruments are used in taper.
high torque, gear reduction and slow speed handpiece. • 0.04 taper is used 3.0–4.0 mm short of apex and 0.02
Quantec files consist of series of 10 graduated Ni-Ti taper is used at the apical end.
taper files; taper ranges from 0.02 to 0.12. The files are In difficult canals, smaller size of instrument is
used in conventional crown-down fashion. Taper preferred.
design 0.08, 0.10 and 0.12 are used for coronal flaring
and others for middle and apical areas accordingly. f. K3 System
These are available in two types of tip design, viz. non-
The K3 system (Ni-Ti instrument, triple fluted and
cutting (LX) and safe-cutting (SC). The LX (non-cutting)
asymmetrical) includes K3 files and K3 body shapers
tip is ideal for routine cases and in delicate apical areas,
(Fig. 11.32). The files are available in taper 0.02, 0.04
whereas SC (safe-cutting) tip is utilized for calcified and
and 0.06; whereas, body shapers have taper 0.08, 0.10
constricted canals.
and 0.12. The body shapers have a shorter taper length
The characteristic features are: (apical 8.0 mm). The fluting on straight (non-tapered)
• Slightly positive rake or blade angle (designed to shank do not cut effectively. The remaining flutes are
shave rather than scrap dentin). parallel, which increase file flexibility. A modified
• Flute design includes a 30° helical angle. version, K3 XF, provides better flexibility and resistance
• Wide radial lands prevent crack formation and to cyclic fatigue (R-phase technology). The differences
reduce the rotational friction. of U-file and K3 file are tabulated in Table 11.9.

e. Hero 642
As the name implies, the files are available in 0.06, 0.04
and 0.02 taper (642). 0.06 taper is available in 21 and
25 mm length; whereas, 0.04 and 0.02 taper are available
in 21, 25 and 29 mm length. The routinely used speed
is 300–600 rpm. The progressively increasing diameter
and distance between the flutes facilitate smooth
guiding without binding in the canal wall. Hero 642
can be combined with sonic MM 1500 handpiece.
The characteristic features are:
• Triangular cutting edges with no radial land
• Positive rake angle (effective cutting)
• Bigger inner core (better resistance to fracture)
• Variable pitch
• Safe tip (stays in centre of the canal).

Hero apical: Hero apical instruments are used for the Fig. 11.32 K3 system
enlargement of apical one-third of root canals, espe-
cially where greater diameters and tapers is required
then offered by Hero 642 and Hero shapers. The Hero Table 11.9 Differences in U-file and K3 file
apical series comprises two instruments both with size U-file (profile, GT, light speed) K3 file
of 0.30 mm with a taper of 0.06 and 0.08 respectively. • Symmetrically placed lands • Asymmetrically placed
lands
Endoflare: Endoflare is Ni-Ti instrument used for
• Equal land widths, flute widths • Unequal land widths;
coronal flaring. The Endoflare is limited to the coronal-
and depths flute widths and depth
third of the canal. The instrument has tip diameter of

11
• Negative rake angle • Positive rake angle
0.25 mm and 0.12 taper. The endoflare has same
characteristics as that of Hero shaper. It has a safe non- • Symmetrical cross-section • Asymmetrical cross-
active tip. section

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 Endodontic Instruments 171

The characteristic features are: The characteristic features are:

• Color coding to distinguish between different tip • The file design provides for alternating contact
sizes and tapers [0.04 (green) 0.06 (orange)]. points, along the instrument's cutting length. The
• A slight positive rake angle provides more effective alternate contact points limit its contact with the
cutting. dentinal walls (thereby reducing torque) and
• A variable core diameter enhances flexibility over simultaneously promote disengagement.
the entire cutting length. • The file has precision non-cutting tip that becomes
• A series of three radial lands with a relief behind fully engaged 1.0 mm from the tip (D1).
two of three lands reduces friction on canal walls. • The file utilizes variable pitch and variable helical
• Asymmetrical flutes provide superior canal tracking; angles. The files with a constant pitch have a tendency
virtually eliminating transportation and aid in to create ‘suck-down’ (tendency of the file to be pulled
preventing the file from screwing into canal. apically as it engages the canal walls). Constant helical
• A safe-ended cutting tip. angles may lead to debris accumulation, subsequently
• Short file handle (access handle—5.0 mm short) leading to file separation. Variable helical angles aid
without affecting working length of file. in removing debris coronally out of the canal.

Technique Technique
• K3 body shapers are used to enlarge coronal one- • The patency of root canal is confirmed with a small
thirds of the root canal. Different taper can be utilized sized file.
in varying diameter of canals. • The expeditor is introduced into the canal and taken
• Initial exploration should be carried out in the to initial engagement. If engagement is met within
presence of EDTA gel along with repeated irrigation. the apical half of the Expeditor’s cutting shank, the
The initial chosen body shaper is followed by ‘small’ Endo Sequence package is opened. If Expeditor
successively smaller body shaper. Used in advance to midway point before engagement is met,
succession, K3 files may take the operator to junction then a ‘medium’ package is selected. If the Expeditor
of middle and apical third. The subsequent K3 files does not meet any engagement, or is loose at full
(0.02, 0.04 and 0.06 taper) allow greater penetration insertion, then a ‘large’ package is utilized.
into apical area. • Begin the crown-down process with the largest file
• The apical area is explored first with hand instrument from the selected package. After the second largest
to determine the apical canal diameter, curvatures, rotary file has been used, determine the working
calcification, patency and ease of negotiation. length with a size 10 hand file (working length is
Beginning with size 6 to 10 K files, operator should generally determined after the second rotary file).
slowly and gently attempt to reach estimated • Once the working length has been determined,
working length as determined by tactile sense and complete the preparation in a straight crown-down
radiographic interpretation. fashion, taking each rotary file to engagement. The
• After true working length is established, a glide path first Endo Sequence file to reach working length with
for subsequent K3 files is established to approximate resistance completes the preparation.
size 15 to 20 K files. Irrigation and recapitulation
should be frequent during apical preparation. K3 h. RaCe
files are introduced with larger to smaller tip sizes ‘RaCe’, is acronym for reamer (R) with alternating (a)
till working length is reached. cutting (C) edges (e). The instrument is available in 0.02,
0.04, 0.06, 0.08 and 0.10 taper design (Fig. 11.33a and b).
g. Endo Sequence System The cross-section of the instrument is triangular with
The Endo Sequence system is available in both 0.04 (size large flutes. These instruments are flexible. The electro-
15–60) and 0.06 (size 15–50) taper files, with lengths of chemical surface polishing decreases distortion and
21, 25 and 31 mm. It is also available in both single fatigue.
instrument packs and procedural packs (small, medium The flutes of RaCe instruments with regular helical
and large). An initial rotary instrument called an angles will only touch the inner surface of elbow of a
‘Expeditor’ is included with the system, which canal curvature for a short distance. The straight part
determines the initial canal diameter. The expeditor is
a size-27 file (length 21.0 mm and taper 0.011). These
files are best suited at a speed of 500–600 rpm.
(straight flutes, no helical angles) of a RaCe instrument
might touch the inner surface of an elbow, which causes
file strengthening.
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 172 Essentials of Endodontics

a b
Fig. 11.33a and b RaCe file

The characteristic features are:

• Special torque controlled motor not required.
• Alternate cutting edges provide anti-screwing
design.
• The safety tip ensures guidance/centering in the
canal.
• Safety memory disc help discarding the instrument
at right time (Fig 11.34).

Technique
• The manufacturer has provided the gadget
(Fig. 11.35), which measures the curvature of the root
canal. Only three types of curvatures are recognized,
viz. simple (S), medium (M) and difficult (D). The
gadget is placed over the preoperative radiograph and
the coinciding curvature is noted (Fig. 11.36). Fig. 11.35 Gadget to measure curvature

11 Fig. 11.34 Components of RaCe file (blue-safety memory disc) Fig. 11.36 Measuring curvature

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 Endodontic Instruments 173

• The manufacturer has also provided the charts,

which signifies the timings as to when the instrument
is to be discarded (Fig. 11.37a and b). For example,
using 0.02 taper RaCe instrument (no. 15), in simple
curvature canals, two petals of safety memory disc
are to be torn. (This means such an instrument in these
similar conditions can be used only for four times,
since safety memory disc has only eight petals.) a
Similarly, 0.04 taper RaCe instrument (no. 25) in
difficult curvature can be used for only once, since
all eight petals need to be torn after use.
• The coronal flaring is carried out with 0.10 taper
instrument, followed by 0.08 taper. Subsequently,
mid preparation is carried out with 0.06, 0.04 taper
and apical preparation with 0.04 and 0.02 taper [the
initial instrument can be modified depending upon b
the canal dimensions; however, sequence must be Fig. 11.37a and b Charts guiding the operator as to when
followed (Fig. 11.38a to f)]. discard the instrument

a b

c d

e f

Fig. 11.38 Clinical use of RaCe: (a) Preoperative; (b) Canal preparation with 0.10 taper RaCe file; (c) Canal preparation
with 0.08 taper RaCe file; (d) Canal preparation with 0.06 taper RaCe file; (e) Canal preparation with 0.04 taper RaCe
file; (f) Canal preparation with 0.02 taper RaCe file
11

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 174 Essentials of Endodontics

i. Variable Taper (V-taper)

The variable taper (V-taper) files, available in both hand
and rotary versions, are having short handle and color
coding (Fig. 11.39). The instrument facilitates deeper
apical shapes with more conservative access. Files are
available in three sizes (length 21, 25 and 29 mm) and
apical diameter 0.2, 0.25 and 0.3. The files are designated
as V10 (from 0 to 4 mm 10% taper; from 4 to 8 mm 5%
taper and from 8 to 12 mm 2% taper), V8 (from 0 to
4 mm 8% taper; from 4 to 8 mm 4% taper and from 8 to
12 mm 2% taper) and V6 (from 0 to 4 mm 6% taper;
from 4 to 8 mm 3% taper and from 8 to 12 mm 2%
taper).
The characteristic features are:
• Parabolic cross-section makes the instrument
extremely safe, resistance to fracture, efficient and
flexible.
• Tip is non-cutting (prevent ledging and transpor-
tation)
• Neutral rake angle
Fig. 11.40 Liberator rotary files
• Variable pitch eliminates screw-in effect and
breakage
• No radial land (land causes dragging, friction and and separation decrease with the use of liberator
heat build-up). (Fig. 11.40). Helical flutes are responsible for self-
threading of the instrument into the canal, subsequently
Technique separation. Usually used for retreatment, since gutta-
The preparation is completed with less number of files percha removal is easy.
[30/10, 25/08, 20/06], for large, medium and small The characteristic features are:
canal respectively. • Cross-section is triangular and lacks radial land,
which provides sharp cutting edges.
j. Liberators
• File operates at higher speeds (1000–2000 rpm).
Liberator is a straight fluted file (all rotary files are • Tip is non-cutting, which minimizes ledging,
helical fluted). The chances of self-threading into canal transportation and helps centering the file in the
canal.
• Debris removal is easy.

Technique
The liberator can be used both for step-back technique
and crown-down technique.
• Initial exploration/glide path is achieved by smaller
number hand files.
• Gates glidden drills are used for coronal preparation,
starting from larger number to smaller number.
• The middle and apical-third is prepared following
the sequence as followed in routine crown-down
technique.
• For step-back technique, the sequence apical to
coronal is followed, with smaller number files to
11 Fig. 11.39 V-taper rotary files
larger number files.
• Continuous irrigation is preferred.

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 Endodontic Instruments 175

k. MTwo Technique
These are Ni-Ti files; the initial set includes four instru- • Instrument is used at the speed of 300 rpm.
ments with variable tip sizes ranging from size 10 to • Glide path is established using small stainless steel
size 25 and taper ranging from 0.04 to 0.06 (Fig. 11.41a K-files.
and b). The instrument is available in three sizes; i.e. • The basic sequence of MTwo files is followed, which
21, 25 and 31 mm with 16 mm cutting blade. Extended provides 25/06 shape to the canal. If need be, larger
cutting blades up to 21 mm are also available for instruments with 0.07 taper can also be used. The
simultaneous cutting of coronal and middle parts.
technique employed with MTwo is designated as
MTwo retreatment files are also available, viz. MTwo
‘simultaneous technique’, wherein crown to apex
R 15/0.05 and MTwo R 25/0.05 with active tip, which
preparation protocol is followed (using smaller
penetrates better in obturating material.
instruments before using larger instrument as is
The characteristic features are:
carried out in step-back technique).
• Colored ring on handle identifies the size.
• Number of groove rings on handle identifies l. EndoWave System
instrument taper [one ring (04 taper), two rings (05 The EndoWave system provides improved quality and
taper), three rings (06 taper) and four rings (07 taper)]. increased efficiency. The files can adapt to different
• Tip is non-cutting, minimizing ledging, transpor- shapes of canal, reducing the risk of canal aberrations
tation, etc. even in curved canals.
• Helical angle is variable and spiral pitch is constant The files are available in sizes 15 to 35 for normal
for smaller instruments. canals and 15 to 25 for curved canals. Corresponding
taper 0.02 to 0.08 is available for normal canal and taper
0.02 to 0.06 for curved canal. The usual length of the
file is 19, 21 and 25 mm. The ISO color coding identifies
the size.
The characteristic features are:
• Triangular design provides sharp cutting edges.
• Negative rake angle.
• Rounded (non-cutting) tip ensures maximum
safety.
• Files are conditioned electrochemically, making
them smooth and harder (can be used at higher
speed).

Fig. 11.41a MTwo motor and handpiece Technique

Crown-down technique is followed with EndoWave
files. Coronal preparation is carried out with size 35|08
taper followed by middle and apical preparation with
30|06 and 25|06 files. Curved canals can be prepared
with 0.04 taper or 0.02 taper depending upon the need.

m. FlexMaster
Flexmaster is a rotary Ni-Ti instrument having a convex
triangular cross-section with sharp cutting edges. The
instrument is available in three tapers, viz. 0.02, 0.04
and 0.06. A FlexMaster initial instrument (Introfile) has
a taper of 11. The tip is rounded and self-centric. Taper
0.02 instruments are available in size 20 to 70, while

11
taper 0.04 and 0.06 are in sizes 20 to 40. The different
tapers are identified by the number of grooves/rings
Fig. 11.41b MTwo files in the shaft. The sizes are ISO color coded.

t.me/Dr_Mouayyad_AlbtousH
 176 Essentials of Endodontics

Technique • Cross-cut design incorporated into middle and

• A torque control motor is required (the recommended coronal one-third of instrument, results in rapid
speed is 150–300 rpm). débridement with no pressure. It makes the
• The usual sequence followed is size 30|06 followed instrument highly efficient and fast.
by 25/06, 20/06 and 30/04. The same can be • Triangular cross-section ensures efficient cutting.
modified depending upon the canal size.
iv. Hyflex X-file
• The apical shaping is carried out with 20/02, 25/02,
30/02 and 35/02 size taper of files. Hyflex X-file provides unique double-fluting, which
enhances cutting efficiency for quick and easy
n. Miscellaneous Rotary Systems instrumentation. The file is available in sizes 8 to 80 in
21 or 25 mm length with ISO color coded handles. The
i. Rigid Body Shapers (RBS) tip is non-cutting and the rake angle is negative
Rigid body shapers consist of a series of four Ni-Ti rotary (Fig. 11.42).
reamer, viz. No.1 (0.61 mm at tip), No. 2 (0.66 mm at
tip), No. 3 (0.76 mm at tip) and No. 4 (0.86 mm at tip). v. Xtreme Reamer with Rapid Safe Shaping
These instruments develop a parallel canal shape. The instrument is meant for aggressive use even at
higher revolutions because of hybrid cutting flute
ii. Pow-R Files design and annular groove safety feature. The annular
Pow-R files are available in both 0.02 and 0.04 taper. ring is present near shaft where fracture normally
These instruments are available in standard ISO sizes occurs.
as well as in half sizes 17.5, 22.5, 27.5, 32.5 and 37.5. The routine crown-down technique is followed.
They follow standard ISO color codes as well. Orifice opener (30/0.09 taper) can be used to create a
funnel shape coronal aspect. Appropriate sized reamer
iii. Titanium Rotary Files
is used to shape the canal; For example, no. 25 (red) for
The files are having a gradual taper to accommodate small canals, no. 30 (blue) for medium canals and
the cross-cut design in middle and coronal one-third no. 35 (green) for large canals. No. 40 (black) is also
of file which optimizes canal flare and increases flexural available for very large canals.
strength. This design makes the instrument highly
efficient. All the instruments and stoppers are color vi. Plastic Endo
coded with groove marked shanks and depth markers. Plastic Endo is polymer endodontic instruments
The files are available in a box containing six instru-
covered with diamond coatings. The available
ments. The box has a measurement gauge incorporated
instruments are F-file, P-file, P-Tip Surgical and Vibe
on one side.
Ultrasonic Piezo unit. The files are for single use only.
The usual taper of the file is: The files have unique design and diamond coating;
• For shaping coronal one-third enable the file to agitate sodium hypochlorite and
– Orifice widener (14% taper) remove remaining dentinal debris without further
– Coronal shaper (9% taper) enlarging the canal.
• For shaping middle one-third The design features of current rotary systems are
summarized in Table 11.10.
– M file (4–7% taper)
• For shaping apical-third
– (Blue) A-file (apical finisher for straight canals)
(3–6%)
– (Red) AF file (apical finisher for curved canals)
(3–6%)
– (Yellow) AXF file (apical finisher for severely
curved canals) (3–6%).
The characteristic features are:
• Non-cutting tip which minimizes risk of apical and
lateral perforations as well as ledge formation.
11 • Variable helical angle which prevents wedging
during canal preparation. Fig. 11.42 Hyflex file

t.me/Dr_Mouayyad_AlbtousH
 Table 11.10 Current rotary systems: cross-section design, taper and other characteristic features
Rotary system Manufacturer Cross-sectional design Diagrammatic Tip design Taper Characteristic features
representation
ProFile Dentsply • Triple-U shape Non-cutting Fixed taper (2, 4 and 6%) • 20-degree helix angle
• Neutral rake angle • Constant pitch
ProTaper Dentsply • Triangular cutting edges Non-cutting Variable taper • Balanced pitch and helix
• No radial lands angle
• F3, F4, F5 files (finishing • Better flexibility
files) have U-flutes • No problem of screw-in
effect in the root canal
ProTaper Next Dentsply • Variable cross-section Non-cutting PT Next 1 Tip 0.17 mm/04 • M-wire technology
(increasing and taper reduces fatigue and
decreasing taper design) PT Next 2 Tip 0.25 mm/06 resist fracture
• Rectangular cross-section taper • Improved flexibility
except in Protaper next 1, PT Next 3 Tip 0.3 mm/07
which has square cross- taper
section PT Next 4 Tip 0.4 mm/06
taper
PT Next 5 Tip 0.5 mm/06
taper
Light speed San AntonioTX • Triple-U shape Non-cutting Uniform taper • Thin, flexible non-cutting
instruments • Radial lands Produces a tapered shape shaft
• Short cutting head
Quantec Series Sybron Endo • S-shape design Cutting (SC) Fixed taper (2, 4, 6, 8, 10 • Progressively larger flute
• Double helical flute Non-cutting (LX) and 12%) space as moved towards
• Positive rake angle distal to the cutting blade
• Two wide radial lands

t.me/Dr_Mouayyad_AlbtousH
Hero 642 MicroMega • Triangular shape Non-cutting Fixed taper (2, 4 and 6%) • Variable pitch
• No radial land • 12–16 mm cutting portion
• Positive rake angle • Improved cutting
efficiency
K3 Sybron Endo • Positive rake angle Non-cutting Fixed taper (2, 4 and 6%) • Variable pitch
• Three radial lands • Variable core diameter
• Improved cutting
efficiency and minimum
friction
FlexMaster VDW • Triangular shape Non-cutting Fixed taper (2, 4 and 6%) • Individual helical angles
• No radial lands 11% taper in initial file prevents screw-in effect
RaCe FKG • Triangular shape (except Non-cutting Fixed taper (2, 4, 6, 8 and • Alternating cutting edges
RaCe 15/02 and 20/02 10%) improves cutting efficiency
which have a square • Flexibility is not effective,
Endodontic Instruments

shape) especially in large files

• Two alternating cutting edges
177

• No radial lands

(Contd…)

11
 11
Table 11.10 Current rotary systems: cross-section design, taper and other characteristic features (Contd.)
Rotary system Manufacturer Cross-sectional design Diagrammatic Tip design Taper Characteristic features
representation
EndoWave J. Morita • Triangular shape Non-cutting Fixed taper (2, 4, 6 and • Continuous wave design
• Negative rake angle 8%) (reduce screw-in effect)
Mtwo Padova • S-shape design Non-cutting Fixed taper (4, 5, 6 and • Variable pitch
• No radial lands 7%) • Steep helical angle
• Minimum core width
Endosequence Brasseler • Triangular shape Non-cutting Fixed taper (4 and 6%) • Alternating contact points
• Variable pitch
178 Essentials of Endodontics

• Variable helical angle

• Precision tip
V-taper Guidance endo • Safe core parabolic Non-cutting • Variable taper • Variable pitch
• No radial land
Liberator Miltex • Triangular shape Non-cutting Fixed taper (2, 4, 6, 8 • Straight fluted file
and 10%) • Variable pitch, no radial
land
WaveOne/Wave Dentsply • Convex triangular Non-cutting • Sizes 21, 25, 31 mm • Wave One Gold has
One Gold cross-section • Taper (6 and 8%) improved flexibility
• Tips modified to follow • Reciprocation prevents
canal curvatures instrument advancing to
• Reciprocation movements its plastic limits
Reciproc system VDW • S-shaped cross-section Non-cutting • Three sizes R25, R40, R50 • Instrument provide greater
• Two cutting edges • Taper 08, 06, 05 flexibility
• Increases resistance to
cyclic fatigue and

t.me/Dr_Mouayyad_AlbtousH
improved cutting
efficiency
Twisted Files Kerr • Triangular cross-section Non-cutting • Available in five tapers • Improved flexibility with
• Positive rake angle 04, 06, 08, 010 and 012 less resistance in the
• Length 23 and 27 mm canal
• R-phase technology resist
fracture
OneShape file Micromega • Variable cross-section Non-cutting • One shape Endoflare • Minimum risk of separation
along the blade 25 mm/012 • Flexible, preferred in
• 3-cutting edge (apical) • One shape glide path curved canals
2-cutting edge (coronal) 14 mm/03
• One shape shaping
25 mm/06, 30/06, 37/06
 Endodontic Instruments 179

Clinical Recommendations • It is advisable to use new instruments/system on

The operator should follow certain principles in order extracted teeth before routine clinical use.
to avoid or minimize fracture and other associated The Do’s and Don’ts for the clinicians are
problems with the use of instruments: summarized in Table 11.11.
• New instruments should be checked for any metal
residues or surface debris prior to use. Such residue o. Newer Rotary Designs
may act as areas of stress concentration and lead to i. One Shape Single Rotary File
fracture. One shape single rotary file system is Ni-Ti with
• The angle and canal curvature should be assessed innovative design features. It is preferred in curved
properly. The operator should proceed cautiously canal negotiation with an easy dynamic. Its non-
during preparation of curved canals. working (safety) tip ensures an effective apical
• A straight line access should be achieved prior to progression avoiding obstructions which may lead to
instrumentation. instrument separation. The single file system works in
• The patency of the canal is to be established using continuous rotation. The preparation is rapid (four
glide path. This will reduce the torsional stresses times faster than conventional rotary system). The
acting on the tip of the file. In case of delicate apical conventional rotary motor is used in a simplified
anatomy or acute curvatures, prefer hand instru- manner.
ments (avoid rotary instruments). One shape files are available in different sizes and
• Torque control electric motors should be used. The taper.
torque settings and manufacturer’s instructions are One shape Endoflare (25 mm/012)
to be followed strictly for better results. One shape Glide path (14 mm/03)
• A crown-down sequence should be followed. This One shape shaping (25 mm/06, 30 mm/06 and
will result in less vertical force and torque; also 37 mm/06).
minimizes stress on tip of the instrument.
• The rotary instrumentation should be limited to Design features
about 5 to 10 seconds. The instrument presents a variable cross-section along
• The files should not be apically forced and clinician the blade. The three different cross-section zones are:
should pull back at the first sign of resistance in the • First zone presents 3 cutting-edge design.
canal. The files should be used in approximately 1.0 to • Second (middle) zone has a cross-section that pro-
2.0 mm deeper increments relative to the last instrument. gressively changes from 3 to 2 cutting edges.
• Adequate irrigation and lubrication should be used • Last (coronal) zone has 2 cutting edges.
during preparation to avoid clogging and frictional
resistance. Advantages
• The flutes of the file should be wiped after every use. • Minimum fatigue along the length of the file
Dipping in 6% hydrogen peroxide and wiping with eliminating the risk of separation.
sterilized cloth will be beneficial. • No prior sterilization before use (economical).
• Examine files regularly before, during and after use • One file is used for the treatment of one tooth.
under magnification. If the file is stretched or has a • Controls risk of infections: Safety for patients and staff.
shiny spot, it should be discarded. • Easy handling.

Table 11.11 Do’s and Don’ts for clinicians

Do’s Don’ts
• Assess canal anatomy thoroughly • Forceful instrumentation
• Achieve straight line access prior to instrumentation • Dry instrumentation
• Use glide path for patency of canal • Rotation for long
• Follow crown-down sequence • Staying in the canal for long
• Use files for 5–10 seconds • Use of same files repeatedly
• Adequate irrigation and lubrication • Use of unclean files
• Wipe flutes after each use (dip in hydrogen peroxide)
• Examine files before, during and after use 11

t.me/Dr_Mouayyad_AlbtousH
 180 Essentials of Endodontics

ii. ProTaper Next iii. Self-Adjusting File (SAF)

The ProTaper Next system comprises five instruments. The Self-Adjusting File (ReDentNova) is a hollow file,
The file design depicts an increasing and decreasing designed as a compressible, thin-walled pointed
percentage tapered design. The multiple progressive cylinder (hollow tube—1.5 or 2.0 mm in diameter), with
taper helps to reduce contact between the cutting flutes a rough outer surface (Fig. 11.44). SAF does not have
of the instrument and the dentin wall, subsequently a solid metal shaft. The internal part of the hollow
reducing the possibility of screw-in effect. It also tube is composed of Ni-Ti lattice. The file has an
increases flexibility and cutting efficiency. asymmetrically positioned tip (conventional Ni-Ti
The first instrument in the system is the ProTaper rotary files tip is symmetrically centered). The
Next X1 with a tip size of 0.17 mm and a 4% taper. This continuous flow of irrigant is provided through the
instrument is used after achieving glide path preferably hollow tube. SAF files have been approved for clinical
by means of hand instruments. The ProTaper Next X2 use. Initial clinical studies have observed better canal
(0.25 mm tip with 6% taper) is used to prepare root preparation with minimum chances of the separation.
canal with adequate shape and taper for optimal The radiographic picture of root canal obturations using
irrigation and root canal obturation. Both X1 and X2 SAF were comparable to other rotary systems.
have an increasing and decreasing percentage tapered Procedure
design over the cutting areas. • The 1.5 mm file may easily be compressed and
The last three finishing instruments are the ProTaper inserted into any canal previously prepared/
Next X3 (0.3 mm tip with 7 % taper); ProTaper Next X4 negotiated with a # 20 K-file. The 2.0 mm file will
(0.4 mm tip with 6% taper); and ProTaper Next X5 easily compress into a canal that was prepared with
(0.5 mm tip with 6% taper). All three have a decreasing a #30 K-file.
percentage taper from the tip to the shank. These files • The file attempts to regain its original dimensions,
are used to either create more taper in a root canal or to thus applying a constant delicate pressure on the
prepare wider root canals (Fig. 11.43). canal walls.
The ProTaper Next files have a bilateral symmetrical • When inserted into a root canal, it adapts itself to
rectangular cross-section offset from the central axis of the canal’s shape, both longitudinally (as will any
rotation (except in the last 3.0 mm of the instrument). Ni-Ti file) and along the cross-section. In a round
The exception is the Pro-Taper Next X1, which has a canal, it will attain a round cross-section; whereas,
square cross-section in the last 3.0 mm segment in an oval or flat canal it will attain a flat or oval
providing core strength in the apical half. cross-section, providing a three-dimensional
The files are manufactured from M-Wire (not from adaptation.
a traditional Ni-Ti alloy), reducing the cyclic fatigue • The surface of the lattice threads is lightly abrasive,
by 400%. These files are more flexible and resist fracture which allows it to remove dentin with a back-and-
during preparation. forth grinding motion.
• The SAF is operated with transline (in and out)
vibrating handpieces with 3,000 to 5,000 vibrations
per minute and an amplitude of 0.4 mm. Such a
handpiece may be the GENTLEpower (360° free

11 Fig. 11.43 ProTaper Next Fig. 11.44 Self-adjusting file (SAF)

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 Endodontic Instruments 181

rotation; Kavo, Germany), MK-Dent head (360° free • Prevention of canal transportation: The SAF file
rotation; MK-Dent, Germany) or RDT3 head (80 rpm being extremely flexible and pliable, does not impose
when free and stops rotating when engaging the its shape on the canal, rather complies with its
canal walls, ReDentNova). original shape. The rotary Ni-Ti files have a tendency
• The irrigation tube is connected to a continuous-flow to transport the canal to the outer side of the
source and has an on-off switch. curvature, especially in curved canals. SAF maintains
• The vibrating movement combined with intimate the apical part of curved canals closer to its original
contact along the entire circumference and length of shape and configuration.
the canal removes a layer of dentin with a grinding • High durability: The SAF file does not have a core
motion. as do other Ni-Ti instruments. Any strain applied to
• The hollow design allows for continuous irrigation it is distributed along the delicate lattice structure.
throughout the procedure. A special irrigation device Fatigue tests have confirmed that SAF can be rotated
(VATEA, ReDent-Nova) is connected by a silicon for more than 150 hours at 900 rpm with a 5.0 mm
tube and provides continuous flow of the irrigant deflection with no mechanical failure; whereas, some
(irrigant is the choice of the operator) at a low of the Ni-Ti rotary instruments separated within the
pressure and at flow rates of 1.0 to 10 ml/minute. first hour. It is also important that the structural
• Alternatively, any physiodispenser type of irrigation failure was not of the separation type that is
device that is primarily designed for implantology, encountered with other nickel-titanium files.
may also be used. Detachment of one of the arches at one of its ends
• The SAF is inserted into the canal while vibrating was the typical mechanical failure. The damaged file
and is delicately pushed in until it reaches the can be retrieved from the canal without any
predetermined working length. difficulty.
• It is then operated with in-and-out manual motion • Continuous irrigation: The SAF operates with a
and with continuous irrigation using two cycles of continuous flow of the irrigant during preparation.
2 minutes each for a total of 4 minutes per canal. The vibration of the file’s metal lattice within the
• This procedure will remove a uniform dentin layer irrigant facilitates its cleaning and débridement
(60–75 mm thick) from the canal circumference. effects. Any irrigant solution can be used along with
• The SAF file is designed for single use. SAF. Vibrating action of the metal lattice facilitates
irrigant supply at the critical apical areas.
Advantages and characteristics • Removal of the smear layer: Smear layer should be
• Adapts itself to the three-dimensional anatomy of removed in order to allow intimate, unobstructed
root canals: Most rotary file systems follow the contact of irrigants with bacteria at the orifices of
widest part of the canal and gradually machine it; dentinal tubules and also to facilitate sealer’s
whereas, the SAF is used as a single file (1.5–2.0 mm adaptation to the canal walls. When 3.0% sodium
diameter) that is narrow and compressed shaped, hypochlorite and 17% EDTA were used as
gradually expands in the canal while removing a alternating irrigants with the SAF file, the root canal
uniform layer of dentin from its walls. Because the surface (including its apical third) was rendered
file adapts itself to the cross-section of a given canal, clean of debris and the smear layer (SAF allows
a canal with a round cross-section is enlarged as a uniform distribution of irrigant solution).
round canal; whereas, an oval canal is enlarged as
an oval canal.
iv. WaveOne/WaveOne Gold
• Uniform removal of the remaining dentin wall
thickness: Ni-Ti rotary files may result in uneven The WaveOneNi-Ti file system utilizes single file to
thickness of the remaining dentin wall especially in prepare the root canal.WaveOne Gold replaces original
flat canals. In places where round bore has been WaveOne series, by improving upon its flexibility
created, the remaining dentin will be thinner in the (Fig. 11.45).
mesial and distal aspects than in the untreated The specially designed WaveOneNi-Ti files work on
areas, which is a predisposing factor for vertical reverse ‘balanced force’ action using a preprogrammed
root fractures. On the other hand, SAF removes a motor to move the files in a back and forth ‘reciprocal
uniform layer of dentin from the canal walls, thus
resulting in a relatively uniform remaining dentin
thickness.
motion’. The files are manufactured using M-Wire
technology, improving strength and resistance to cyclic
fatigue.
11

t.me/Dr_Mouayyad_AlbtousH
 182 Essentials of Endodontics

cross-section at the coronal end. This design improves

instrument flexibility; the variable pitch improves
safety. The tips are modified to follow canal curvature
accurately.
It is hypothesized that root canal instruments cannot
be sterilized property; therefore, the concept of root
canal files in single use became popular. The plastic
colour coding in the handle become deformed once
sterilized, preventing the file from being placed back
into the handpiece.
The single use file has the advantage of reducing
instrument fatigue (one file can carry out preparation,
which in routine performed by three or more rotary
Ni-Ti files).
The WaveOne motor, as supplied by manufacturer is
rechargeable; battery operated with a 6 : 1 reduction
handpiece. The motor work on the principles of
reciprocation, which can be preprogrammed. The
counter-clockwise movement (advances the instrument/
cutting the dentin) is greater than the clockwise
(disengages the instrument). Three reciprocating cycles
complete one reverse rotation; the instrument advances
into the canal with minimum apical pressure.
Selection of WaveOne files
The resistance of first hand file into the root canal aids
in selection of the WaveOne file as:
• If a 10 K-file feels resistant, use WaveOne small file.
• If a 10 K-file moves to working length easily (loose
at constriction), use WaveOne primary file.
• If a 20 K-file or larger touches working length, use
WaveOne large file.
Irrigation is continually carried out during root canal
preparation. The hand file is inserted to working length
and confirm with an apex locator and radiograph. Take
WaveOne file to working length.Confirm apical area
preparation with hand file and the same size as
Fig. 11.45 WaveOne Gold files WaveOne file; if snugly fit, the preparation is complete.
If foramen diameter is larger than WaveOne primary
There are three files available in lengths of 21, 25 and file, consider the next larger WaveOne file.
31 mm in the WaveOne single-file reciprocating system:
Guidelines
• WaveOne Small file is used in fine canals. The file size
is 21 mm with a continuous taper of 6%. • WaveOne files should be used with a progressive
up and down movement with little pressure (not
• WaveOne Primary file is used in the majority of canals.
more than three to four times).
The file size is 25 mm with an apical taper of 8% that
reduces towards the coronal end. • The field should be cleaned continuously.
• WaveOne Large file is used in large canals. The file • Smaller WaveOne file should be used first, followed
size is 31 mm with an apical taper of 8% that reduces by the next in size.
towards the coronal end. • Glide path can be used, if required.

11 The WaveOne files are designed to work with a • In curved canals, apical area is prepared by hand files.
reverse cutting action. All instruments have a modified • Constant irrigation is mandatory throughout the
convex triangular cross-section at the tip and a triangular preparation.

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 Endodontic Instruments 183

Advantages RECIPROC® instruments are designed (S-shaped

• One Ni-Ti file is required per root canal/per tooth. cross-section) using M-wire technology with Ni-Ti. The
• Single use file overcomes the problem of sterilization instrument provides increased resistance to cyclic
and cross-contamination. fatigue and greater flexibility. The deeper flutes
• Less instrument separation (reciprocating movement facilitate excellent removing of debris from the root
prevents the instrument advancing to its plastic limit). canal. The S-shaped cross-section with two cutting
• The canals can be shaped as per requirements. edges provides high cutting ability.
• Eliminates procedural errors by using a single file
rather than using multiple files. vi. Twisted Files
• Easy to manipulate. The twisted files are created by taking a raw Ni-Ti wire
• Cost-effective. in the austenitic crystalline form and transforming the
same into the rhombohedral (R-) phase by a heat
v. RECIPROC® System treatment process. The transformation of the wire from
The RECIPROC system utilizes reciprocation movement austenite to R-phase takes place on cooling to the
wherein the root canal is prepared by using only one file. R-phase transition temperature. R-phase technology
RECIPROC Endomotor is also available for reciprocating provides good superelasticity and shape memory effect;
movements. The use of glide path is also not advised. Young’s modulus is also lower than that of austenite,
The file is available in three sizes R25, R40 and R50. making it more flexible. It also provides adequate
strength to the file.
R25 (Taper 08) color–red
R40 (Taper 06) color–black Twisted files track the root canal with excellent tactile
R50 (Taper 05) color–yellow; non-cutting lips control and the canal can be shaped in limited
insertions.
The RECIPROC file is moved in a cutting direction
and then reverses to release the file. The 360° rotation Twisted files are available in five tapers (0.12, 0.10,
is completed in several reciprocating movements. The 0.08, 0.06, 0.04); and two lengths, 23 and 27 mm.
centering ability of the reciprocation technique allows Large pack includes 0.10, 0.08, 0.06 tapers and small
the instrument to follow the path of least resistance, pack 0.04, 0.06, 0.08 taper. Generally, the large pack is
especially in curvatures (Fig. 11.46). used in straight and easily negotiable canals; whereas,
small pack is used in small and curved canals.
Tip: Non-cutting pilot tip
Rake angle: Positive rake angle
Speed: 500 rpm
Cross-section: Triangular

Advantages of twisted files

• Triangular cross-section enhance flexibility and
generates less friction inside the canal.
• Variable pitch minimizes ‘screw-in’ effect and
appropriate flute width and flute depth effectively
collect debris from the canal.
• One piece design (file is manufactured from one
piece Ni-Ti) minimize ‘wobble’ during rotation. One
piece file provides more structural integrity.
• Surface conditioning maintains the surface hardness
and the sharpness of edges.

Advantages of R phase technology

• Overcomes limitations of grinding file technology.
• Improves properties of Ni-Ti alloy.

Fig. 11.46 RECIPROC system

• Crystalline structural modification provide maximum
flexibility and resistance to breakage.
11

t.me/Dr_Mouayyad_AlbtousH
 184 Essentials of Endodontics

vii. TRUShape 3D Conforming Files • Greater resistance to fracture due to cyclic fatigue.
TRUShape 3D is a new file system that preserves more • Increased torque strength.
tooth structure (removes 36% less dentin as compared
to conventional files).The file prevents apical ix. F360 file system
transportation, producing predictable apical shape. F360 file system is designed with a unique double-S
It has ‘S’-shaped design facilitating flexibility and shape cross-section, sharp cutting edges and larger flute
creating an envelope of motion that better disrupts spaces. The design ensure better cutting efficiency and
polymicrobial biofilms. removal of infected debris. The system utilizes two files
It is used in conjunction with TRUShape orifice for preparation of most of the root canals (size 25/04 –
modifiers. The file design provide active cutting cross- red and size 35/04 – green). Additional file sizes (size
section, a fluted length of 7.0 mm, fluted diameter of 45/04 – white and size 55/04 – red) are used for wider
0.75 mm and Ni-Ti for strength and flexibility. The files canals. The length available are: 21, 25 and 31 mm.
are available in four tip sizes of 20, 25, 30, 40 and lengths Corresponding sized paper points and gutta-percha are
21, 25 and 31 mm. also available.
The presterilized, single-use files are designed to
viii. Vortex Blue prevent cross-contamination, easy to maintain sterility
Vortex blue is a new file system, which provides greater and less chances of fracture due to cyclic fatigue.
resistance to cyclic fatigue, greater strength and reduced Advantages
shape memory; also conforms to canal curvatures.
• Improved flexibility
The ‘Blue Color’ of the file is due to an optical effect,
created by light rays interacting with a Titanium oxide • No canal transportation or other procedural errors
layer on the surface of the file. • Resist fracture
It is triangular in cross-section with safe ended tip and • Single-use (saves time and cross-contamination)
variable helical angle. The lower helical angle (less flutes) • No need to sterilize the file.
in the coronal portion of the file facilitates efficient
debris removal and higher helical angle (more flutes) x. NeoNi-Ti
in the apical portion of file provides increased strength. NeoNi-Ti is a new file system having rectangular
The files are available in lengths 21, 25 and 30 mm section along the blade, which provides progressive
and 4 and 6% taper (packs of six files: color varies with flexibility to better negotiate the root canal curves. The
file number, Table 11.12). file also provides better cutting efficiency and less smear
In conventional canals, 30/04 file is used up to layer formation.
working length; 40/04 file is used in wider canals and Appropriate heat treatment of the files can increase
15–20/04 file is preferred in narrow canals. If resistance the flexibility and resistance to fatigue. The single
is encountered before working length, the next smaller file technique is easy to use. Recommended speed is
file is chosen following same protocol until working 300–500 rpm.
length is achieved. Between each rotary files, Two variants are available:
recapitulate with no. 10 or 15 hand file to maintain glide
path. NeoNi-Ti C1: It is an orifice-opener. Diameter at tip:
0.25 mm with taper of 12%. Length of file: 15 mm.
Advantages
NeoNi-Ti A1: Single file used for shaping of root canal
• Vortex blue files remain centered in the canal, due in continuous rotation. Diameter at tip can be 0.20, 0.25,
to reduced shape memory effect. and 0.40 mm with taper 8%. Length of file: 21 and 25 mm.

Table 11.12 File number and color (Vortex blue) xi. ProTaper Gold Rotary Files
4% and 6% taper ProTaper Gold files have same features and predictable
White 15 performance as ProTaper Universal (Fig. 11.47).
Yellow 20 The files provide greater flexibility and have greater
Red 25
resistance to cyclic fatigue and enhanced durability.
The 11 mm short handle provides better accessibility.
Blue 30

11 Green
Black
35
40
The system includes series of ‘shaping’ and
‘finishing’ files that create the predictable ProTaper
Shape (Table 11.13).

t.me/Dr_Mouayyad_AlbtousH
 Endodontic Instruments 185

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2. Alapati SB, Brantley WA, Svec TA, Powers JM, Nusstein JM
and Daehn GS. Proposed role of embedded dentin chips for
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i. Endobox: A small box, an organizer for placement
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fragmented/separated instruments from the self-adjusting file (SAF) Part 1: Respecting the root canal
coronal half of the root canal. anatomy—a new concept of endodontic files and its
v. Perf paddles: Perf paddles are mainly available in implementation. J. Endod.: 2010; 36:679–690.
two sizes, viz. 1 and 2; used to repair perforations 16. Metzger Z, Teperovich E, Zary R, Cohen R, Paque F,
inside root canal. Hulsmann M and Hof R. The self-adjusting file (SAF) Part 3:
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vi. LC-condenser: LC-condenser, available in two sizes, microscope study. J. Endod.: 2010; 36:697–702.
is used to condense material in root-end cavities
17. Montalvao D, Alcada FS, Fernandes FM and Vilaverde-
(surgically prepared cavities).
Correia S. Structural characterization and mechanical FE
vii. Flap retractors, needle holder, burnishers, currettes,
etc. of various shapes and sizes are available for
respective usage.
analysis of conventional and M-wire Ni-Ti alloys used in
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ID976459:1–8.
11

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 186 Essentials of Endodontics

18. Paque F, Barbakow F and Peters A. Root canal preparation 25. Shen Y, Jeffrey MC, John A, Wang Z, Hieawy A, Yang Y and
with Endo Eze AET: Changes in root canal shape assessed by Haapasalo M. WaveOne rotary instruments after clinical use.
micro-computed tomography. Int. Endod. J.: 2005; 38:456. J. Endod.: 2016; 42:186–189.
19. Parasbos P. Rotary Ni-Ti instrument fracture and its 26. Shen Y, Zhou H and Zheng YF. Metallurgical characterization
consequences. J. Endod.: 2006; 32:1031–1043. of controlled memory wire nickel-titanium rotary instruments.
J. Endod.: 2011; 37:1566–71.
20. Peters OA and Paque F. Current developments in rotary root
canal instrument technology and clinical use: A review. 27. Shen Y, Zhou H and Zheng YF. Current challenges and
Quint. Int.: 2010; 41:479–488. concepts of the thermomechanical treatment of nickel-
titanium instruments. J. Endod.: 2013; 39:163–172.
21. Plotino G, Grande NM and Porciani PF. Deformation and
28. Shen Y, Zhou H, Coil JM, Aljazaeri B, Buttar R, Wang Z,
fracture incidence of Reciproc instruments: a clinical
Zheng Y and Haapasalo M. ProFile Vortex and Vortex Blue
evaluation. Int. Endod. J.: 2015; 48:199–205.
Nickel-Titanium rotary instruments after clinical use. J.
22. Plotino G, Pameijer CH, Grende NM and Somma F. Ultrsonics Endod.: 2015; 41:937–942.
in endodontics. A review of literature. J. Endod.: 2007; 29. Thompson SA. An overview of Nickel-Titanium alloy used
33:81. in dentistry. Int. Endod. J.: 2000; 33:297–310.
23. Saber SEM. Factors influencing the fracture of rotary nickel- 30. Vallabhaneni S, More GR and Gogineni R. Single File
titanium instruments. Endod. Practice: 2008; 2:273. Endodontics. Ind. J. Dent. Adv.:2012; 4:822–826.
24. Sattapan B, Nervo GJ, Palamara JEA and Messer HH. Defects 31. Varela-Patino P. Alternating versus continuous rotation: a
in rotary nickel-titanium files after clinical use. J. Endod.: comparative study of the effect on instrument life. J. Endod.:
2000; 26:161–165. 2010; 36:157–159.

11

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Chapter
12
Sterilization of
Endodontic Instruments

The word ‘sterile’ means absence of any living Formalin use (fumigation) is obsolete in many
organisms. A disinfectant is a chemical substance that countries because of its potentially carcinogenic
kills microorganisms on any object, may be instruments, nature. Frequent use of inhalation is hazardous.
tables, lights, etc. An antiseptic is a chemical that is Newer agents are being used to sterilize the room.
applied to inhibit the growth of microorganisms
iv. Newer agents for sterilization of operating area
(asepsis is absence of micro-organisms in living tissues).
are:
Sterilization of operating field and the instruments is
mandatory for any successful procedure. It is manda- • Bacillocid rasant (composition: Glutaraldehyde,
tory to sterilize endodontic instruments so as to achieve Benzalkonium chloride and dimethyl ammonia).
successful results. The wide range of endodontic It is formalin-free disinfectant with excellent
instruments are sterilized following different modalities cleaning properties and is cost-effective. It
and kept in a sterile field prior to use on patients. The provides complete asepsis within one hour;
effectiveness of sterilization is the beginning of closing the room for 12 hours is not required.
successful endodontic procedures. Aseptic techniques • Virkon: It is non-aldehyde compound (composition
were performed in early nineteenth century; later, the potassium monosulphate, sulfamic acid and
use of surgical gloves, masks and gowns became a sodium dodecyl-sulfonate), considered safe
routine procedure. virucidal and fungicidal. It is effective within
30–40 minutes.
STERILIZATION OF OPERATING ROOM
The operating area/chamber is to be sterilized for better STERILIZATION OF INSTRUMENTS
clinical outcome. The complete eradication of bacteria
The sterilization of instruments involves the following
may not be possible in operating room. The source of
bacteria can be from air, patients attending the area, features:
articles in the room, working equipment, etc.
Processing of Instruments Prior to Sterilization
The methods used to keep the operating area
bacteriologically safe are: This includes pre-soaking and cleaning, rinsing, drying
i. Air flow is filtered; circulating purified air and and packaging before the instruments are being
continuously removing the contaminated air. The sterilized.
patients are allowed in the area ‘off shoes’ and
preferably in sterilized gowns. Presoaking and Cleaning
ii. Standard cleaning and disinfection procedures should Presoaking of contaminated instruments keeps them
be followed, which minimizes the bacterial growth. wet until a thorough cleaning can be carried out. This
iii. Fumigation of the area with formalin fumes. Since prevents drying of blood, saliva and debris on
formalin is pungent, the procedure is carried out instruments, which facilitates cleaning. In endodontics,
overnight in a closed environment. The room is kept all debris must be removed from instruments prior to
closed for 12–14 hours and is ready for use once all sterilization, since it may interfere with the effectiveness
the fumes are out. Formalin is usually neutralized of the procedure. The files possess complex design,
with ammonia (2-hour contact) prior to use of the which facilitates the debris accumulation along the
room. flutes.

187

t.me/Dr_Mouayyad_AlbtousH
 188 Essentials of Endodontics

The methods used for cleaning are: The detergent used in washer disinfector should
have:
i. Manual Scrubbing
• Anti-lipid action at high temperatures
Manual scrubbing involves:
• Anti-protein action at low temperatures
• Use of stiff nylon cleaning brushes
• Enzymatic action.
• Use of neutral pH detergents
For disinfection process, the temperature of water is
• Brush delicate instruments carefully and slowly; the
elevated gradually to almost its boiling point. The
general instruments are cleaned separately
phases of disinfection are:
• Wipe the endodontic instruments with suitable sized
gauze moistened with hydrogen peroxide/alcohol • Initial microbial activation phase (45 to 52°C):
Endospores enter vegetative phase.
• Heavy utility gloves should be worn while pro-
cessing contaminated instruments • Microbial inactivation phase (85 to 95°C): Pathogenic
• The instrument surfaces should be visibly clean and microorganisms are inactivated or killed. Vegetative
free from stains and tissues. endospores are also killed. The contact time is
reduced as the temperature increases.
ii. Ultrasonic Cleaners
Disadvantage
The ultrasonic cleaners use vibratory energy, carried
• Maintenance of disinfected instruments is difficult
as sound waves in the fluid, creating suction, which in
since, they are obtained in a wet and unwrapped state.
turn removes biological matter from the instruments.
An ultrasonic cleaning device should have a lid, a iv. Enzyme Cleaners
well-designed basket and an audible timer. The device
Enzymes are powerful tools for cleaning endodontic
should prevent electronic interferences with other
instruments. A properly selected enzyme cleaner can
electronic equipment and office communication
effectively improve cleaning of instruments. Enzymes
systems (Fig. 12.1).
accelerate the biological process of the chemicals, and
Advantages are specific in their catalytic behavior. Some enzymes
• Faster: Easier in cleaning are effective on specific proteins while others may act
• Removes dried blood and saliva on a broad-spectrum of proteins, e.g. KLENZYME
• Minimizes the direct handling of contaminated cleaners.
instruments, subsequently the accidental injuries to Since, the enzymes normally used for instruments
hands. cleaning do not attack metals; they are well-suited for
cleaning the reusable instruments.
iii. Washer Disinfector
Disadvantages
Washer disinfector helps in effective physical cleaning
due to high flow of water, (both volume and pressure), • Enzymes may lead to corrosion, rust, discoloration
which is sprayed all over the instruments. Temperature and loss of elasticity of the instruments.
is maintained below 45°C to avoid any protein • Improper use of cleaning solutions can also lead to
coagulation during the flushing stage. stained surfaces.
• Another important attribute of enzyme cleaners is
their rinsability. In case enzymes cling to instrument
surface, rather than rinse off easily under running
water, they can interfere with sterilization process
by hiding bacterial contamination. The residual
enzymes may also interfere with sterilization.

Packaging
After cleaned instruments have been rinsed and dried,
they are to be packed in functional sets before steriliza-
tion. This packaging protects the instruments from
contamination after sterilization and before use at chair-

12 Fig. 12.1 Ultrasonic cleaner

side. A variety of packaging materials are available,
with self-sealing paper-plastic and peel pouches being
the most convenient.

t.me/Dr_Mouayyad_AlbtousH
 Sterilization of Endodontic Instruments 189

Studies have shown that it is difficult to remove

organic debris from endodontic files despite using
automated cleaning devices. It is important to ensure
that instrument holders, such as cassettes or file holders
have perforations and allow adequate space between
instruments to allow access to all instrument surfaces
during the cleaning process.
Because of the challenges of cleaning files, deteriora-
tion of the cutting surfaces during cleaning and
sterilization, and wear during normal use, the Centre
for Disease Control and Prevention (CDC) suggest
considering endodontic files as single-use devices.

Sterilization
The techniques used for sterilization of instruments are:
1. Flaming
2. Boiling
3. Cold sterilization
4. Autoclave
5. Dry heat sterilization
6. Glass bead sterilizer
7. Hot salt sterilizer Fig. 12.2 Cold sterilizer
8. Ethylene oxide sterilization
9. Plasma sterilization v. Sporicidin (phenol 7.05%, sodium tetraborate 2.35%,
Glutaraldehyde 2% and sodium phenate 1.2%):
1. Flaming
Disinfects instruments in 10 minutes at room
The instruments are sterilized by dipping in alcohol temperature and sterilizes in 6.75 hours.
(3 parts of ethyl alcohol and 1 part formalin) and
passing over the flame 2–3 times. The process destroys Disadvantages
even spores. The tips of tweezers, scissors, etc. can be • Not effective against all varieties of microbial life
sterilized using this method; however, root canal files • Time taken is long (minimum 20 minutes for proper
reamers, etc. should not be sterilized by this method. sterilization).
2. Boiling 4. Autoclave
Boiling in water for fifteen minutes will kill most Autoclaving is one of the most rapid and effective
vegetative bacteria and inactivate viruses; however, method for sterilization.
boiling is ineffective against many bacterial and fungal Sterilization in an autoclave (Fig. 12.3) is carried
spores. It is considered unsuitable for complete out with steam (250°F or 121°C) under pressure (15 lb).
sterilization. For a light load of instruments, the time required is
3. Cold Sterilization fifteen minutes. The burs can be protected by keeping
them submerged in a small amount of 2.0% sodium
Cold sterilization (Fig. 12.2) uses chemical solutions
nitrite solution. Carbon steel instruments tend to rust
such as:
with autoclaving. Handles of endodontic hand
i. Quaternary ammonia compounds: Useful for vegeta-
instruments are made up of high quality plastic which
tive microorganisms.
can bear high temperature exposures. A few
ii. Ethyl alcohol and isopropyl alcohol: Useful for vegeta- manufacturers claim that the plastic of their instruments
tive bacteria and tubercle bacilli. are high heat resistant which can be used even in dry
iii. Alcohol-formalin solution: Useful for vegetative heat sterilizers.
bacteria, tubercle bacilli and spores.
Advantages
iv. Orthophenylphenol and benzyl-para chlorophenol:
Useful for vegetative bacteria, tubercle bacilli, certain
fungi and viruses, but not on spores.
• Most rapid and effective method
• Good penetration of heat.
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t.me/Dr_Mouayyad_AlbtousH
 190 Essentials of Endodontics

6. Glass Bead Sterilizer

Glass bead sterilizer (Fig. 12.5) contains glass beads,
less than 1.0 mm in size because larger beads are not
effective in transferring heat due to large air spaces
between the beads. The instruments to be sterilized are
immersed into the heat-up glass beads (temperature
218–280°C) and left for a specific period of time. The
time specified for each instrument is:
• Root canal instruments: 5 seconds
• Absorbent points and cotton pellets: 10 seconds
• Long-handled instruments, tips of cotton pliers,
blades of scissors and tips of other surgical instru-
Fig. 12.3 Autoclave
ments: 5 seconds.
Disadvantages Disadvantages
• Plastic and rubber cannot be sterilized
• The glass beads (less than 1.0 mm in diameter),
• Tend to rust carbon steel instruments. sometimes get stuck in the instruments like broaches
5. Dry Heat Sterilization or cotton pellets, which may get introduced into the
root canal and hamper root canal preparation.
Dry heat sterilization effectively kills bacteria without
• Costlier than the salt sterilizer.
changing the sharpness of the instruments. It works
without pressure, steam or chemicals, which increases • Considered effective only as auxiliary method of
safety (Fig. 12.4). Utility trays can be sterilized with lids sterilization.
on and stored without contamination. It is economical
to use and requires no routine cleaning. 7. Hot Salt Sterilizer
Hot salt sterilizer is used to sterilize absorbent points,
Advantages broaches, files, reamers and other root canal instru-
• Maintenance of sharp edges of cutting instruments ments. The method is preferred to sterilize root
• No corrosion of instruments canal instruments immediately before start of the
• Packs are dry after sterilization treatment.
• Rapid cycles at higher temperature possible
• Less expensive.
Disadvantages
• Poor heat conduction by air (prolonged time)
• High heat damages plastic and rubber items
• Sterilization prolonged at lower temperature.

12 Fig. 12.4 Dry heat sterilizer Fig. 12.5 Glass bead sterilizer

t.me/Dr_Mouayyad_AlbtousH
 Sterilization of Endodontic Instruments 191

Technique
The instruments desired to be sterilized are put into
the sterilizer and left for a stipulated period of time
(different instruments have different time limits);
Broaches, files and reamers are sterilized in 5 seconds;
whereas absorbent points and cotton pellets in 10
seconds. The hottest part of the salt bath is along the
outer rim, starting at the bottom. Immerse instrument
at least a quarter inch below salt’s surface and in the
peripheral area. It consists of a metal cup in which table
salt is kept at a temperature of 425°F [218°C] to 475°F
[246°C]. Use of thermometer to monitor temperature
of the salt is necessary. It is considered superior to
molten metal sterilizer and glass bead sterilizer because
the metal or the glass beads occasionally cling to the
wet instrument and tend to clog the root canals.
Advantages
• Use of table salt (readily available).
• Contains small amounts of sodium silicoaluminate,
magnesium carbonate or sodium carbonate, so it
Fig. 12.6 Ethylene oxide sterilizer
pours readily and does not become fused under
heat.
• Any salt carried into root canal can be irrigated
easily.
• Salt should be changed every week; or more often
depending on the degree of humidity.
• Cost-effective (salt is cheap and easily available).

8. Ethylene Oxide (ETO) Sterilization

Ethylene oxide sterilization is a lengthy process. It is
generally carried out at temperatures (30 and 60°C) with
relative humidity above 30%. The gas concentration is
maintained between 200–800 mg/l for at least
3 hours (Fig. 12.6). The process also involves a period
of poststerilization to remove any toxic residues. The
gas is extremely dangerous at ambient oxygen levels
and its mixtures with air are explosive. When heated,
it may rapidly expand causing fire and explosion.
Hence, its use has been discarded.

9. Plasma Sterilization
Plasma is basically ionized gas. Plasma sterilization is Fig. 12.7 Plasma sterilizer
fast evolving into a promising alternative to standard
sterilization techniques. It uses a technique, which Advantages
involves UV irradiation, photodesorption and chemical • The process is carried out usually at room tempera-
etching. The spores are made up of atoms like carbon, ture and hence poses no dangers associated with high
oxygen, hydrogen, nitrogen and the like. The radicals temperatures.
react with these atoms to form compounds like carbon • It does not involve any chemicals and hence is non-
toxic (unlike ethylene oxide).
dioxide, which can be subsequently flushed out. When
the organism loses such atoms that are intrinsic to its
survival, it dies (Fig. 12.7).
• Time of treatment is fast (one minute or less).
• It is versatile and can sterilize almost any instrument.
12

t.me/Dr_Mouayyad_AlbtousH
 192 Essentials of Endodontics

10. Laser Sterilization

Carbon dioxide laser has been widely used as one mode
of sterilization. It is considered effective in complete
eradication of the bacteria from the instrument surfaces.
Argon layer and ND:YAG have also been used to
sterilize endodontic instruments. Argon Laser is
considered better than the other two lasers.

STERILIZATION OF HANDPIECE AND TURBINES

The dental handpiece and turbines (waterlines) due to
constant contact with oral fluids are contaminated on
both external and internal surfaces.

a. Sterilization of Handpiece
Sterilization of handpiece is carried out as:
• Wipe the handpiece clean with an alcohol soaked
soft tissue.
Fig. 12.8 Ultraviolet lamp
• Never clean the handpiece with boiling water, chemical
solution, ultrasonic cleaner or with wire brushes.
b. Sterilization of Dental Unit Waterlines
• The manufacturer’s instructions for cleaning and
lubrication must be followed to reduce the risk of It is established that dental personnel are constantly
turbine degradation. Various cleaning solutions and exposed to water borne microorganisms. There are
foam are available to lubricate inner surfaces. various ways by which waterborne microorganisms can
Automate devices are also available for cleaning and cause infection in a patient undergoing dental
lubricating. Failure to lubricate handpiece (except treatment, viz. homogenous spread during surgical
tube-free handpiece) contribute significantly to early procedures, local mucosal contact, ingestion and
bearing failure. inhalation. A range of microbiological flora has been
• It is best sterilized by autoclaving for no longer than identified in dental unit waterline samples which holds
20 minutes at 121°C (250° F) or 15 minutes at 132°C potential to infect healthy dental patients.
(270°F). A number of products are being used to help control
• Keep the handpiece away from water vapour or mist the problem:
that may settle and cause premature damage to the • Filters: Filters provide physical barrier to the passage
bearings. of microorganisms. Filters do purify water before it
• Ethylene trioxide has been used as an alternative enters the dental unit. Certain fillers are impregnated
method for sterilization of dental handpiece as it is with iodine, which is gradually released into the
less corrosive than steam. However, its effectiveness water during use of the handpiece; minimizing
has not been established. bacterial counts.
• Most handpieces require lubrication before steriliza- • Supply of autoclaved water: The sterile water is
tion (except tube-free handpiece). supplied in each component of the delivery system.
• It is advised to wrap the handpiece in a piece of cloth Practically this method is difficult and not cost-
before placing it in the autoclave. An unwrapped effective; moreover, sterile water in pipes becomes
handpiece should be used immediately or sterilize contaminated soon, because of inherent biofilm
again before use. inside the pipes.
• Chemical vapour pressure sterilization (chemiclave) • Chemical disinfectant: The disinfectants are allowed
is recommended for ceramic bearing handpieces. to remain in waterlines overnight and then powder,
• Dry heat sterilization of handpieces is generally not if used, should be kept in the pipes for shorter time
recommended.
12
and then rinsed with fresh water. Rinsing out water
• Ultraviolet radiations are used for maintenance of lines of the unit with Tween 80 and Ponceau 4R dye
previously sterilized handpieces (Fig. 12.8). lead to a marked reduction in microorganisms.

t.me/Dr_Mouayyad_AlbtousH
 Sterilization of Endodontic Instruments 193

Canadian Dental Association guidelines for maintenance of Indicators for Sterilization

dental unit waterlines 1. Biological indicators: The spores of Geobacillus
• Avoid heating water for the dental unit stearothermophilus ATCC 7953 and Bacillus atrophaeus
• At the beginning and after each patient, purge all lines by ATCC 9372 are exposed to sterilization and thereafter
removing handpiece, air/water syringe, ultrasonic tips etc. incubated. There should be no trace of living spores
Flushed thoroughly with water (decrease in bacterial count
in case of effective sterilization.
with purging is established).
• Run high speed handpiece for 20–30 seconds after each 2. Chemical indicators (integrators): These are chemical
patient to purge all air and water. compounds which indicate process completion by a
• Use sterile water/saline when flushing open vascular sites and/ color change. As compared to biological indicators
or cutting bone during invasive surgical procedures. these give instant results. These are available in the
• Follow manufacturer’s instructions for daily/weekly form of chemical indicator tapes although the change
maintenance, if using bottled water or other special delivery in color does not signify effective sterilization; it
system. merely signifies process completion.
3. Process challenge device: The hollow devices, such
STERILIZATION OF MISCELLANEOUS INSTRUMENTS as catheters, needles, aspiration syringes, drills, etc.
need both outer surface and inside to be sterilized.
• Burs must be clean before sterilization. The burs
Hence, this device was created to simulate hollow
should be presoaked in a container of soapy water
instruments. It has a long tube connected to a capsule.
to loosen debris. The enzymatic solution is used to
A chemical integrator is placed inside the capsule
clean the diamond points. Ultrasonic system can also
and then closed. It thus takes the shape of one end
be used. After rinsing, the burs must be thoroughly
open device. A successful change in color of the
dried by placing them on absorbent towel. Burs,
chemical integrator inside the process challenge
especially the surgical burs, are sterilized by heat.
device on completion of the process of sterilization,
Cold sterilization is not recommended for burs, since
guarantees sterilization of inside of all hollow devices.
the oxidizing agents may weaken carbide burs.
The presence of all parameters of sterilization inside
Steam autoclaves effectively sterilize burs.
the sterilizer, further guarantees sterilization of both
• Glass slab can be sterilized by swabbing with tincture the surfaces.
of thimerosal, followed by a double swabbing with Biological indicator needs to be used after certain interval
alcohol. of time or after major maintenance and repair of the sterilizer
• Gutta-percha cones may be kept in sterile screw capped as part of process of Validation. Routine monitoring on day
vials containing alcohol. (To sterilize gutta-percha to day basis is best carried out by chemical integrators
cone freshly removed from the box-immerse in 5.2% through process challenge device.
sodium hypochlorite for one minute, then rinse with
hydrogen peroxide and dry between two layers of BIBLIOGRAPHY
sterile gauze.)
1. Dallolio L,Scuderi A, Rini MS, Valente S, Farruggia P, Sabattini
• Silver cones are sterilized by passing them through a MA, Pasquinelli G, Acacci A, Roncarati G and Leoni E. Effect
flame 3–4 times or by immersion in hot salt sterilizer of different disinfection protocol on microbial and biofilm
for 5 seconds. contamination of dental unit waterlines in community dental
practices. Int. J Environ. Res. Public Health: 2014; 11:2064–
• Dappen dishes can be sterilized before use by
2076.
swabbing with tincture of thimerosal under pressure.
2. Gasparini R, Pozzi T, Mangeli R and Fatighenti D. Evaluation
• Infected endodontic instruments exposed to three of in vitro efficacy of the disinfectant Virkon. Eur. J Epidemiol.:
seconds to a laser beam destroys microorganisms 1995; 11:193–197.
including spores. 3. Ghinzelli GC, Souza MA, Cecchin D, Farina AP and de
Figueiredo JA. Influences of ultrasonic activation on
How does an effective sterilization take place? photodynamic therapy over root canal system infected with
Enterococcus faecalis—an in vitro study. Photodiagnosis
Each process of sterilization has certain parameters such Photodyn. Ther.: 2014; 11:472–478.
as temperature, time, humidity and saturation/ 4. Harsoor SS and Bhaskar SB. Designing an ideal operating
concentration of chemical agent, if used. If an effective room complex. Indian J Anaesth.: 2007; 51:193–197.
sterilization is to be achieved, running a full cycle is
not enough; it must also be established that the cycle
was run under conditions following all the parameters.
5. Herd S, Chin J, Palenik CJ and Ofner S. The in vivo contamina-
tion of air-driven low-speed handpieces with prophylaxis
angles. J Am. Dent. Assoc.: 2007; 138:1360–1365.
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6. Hooks TW, Adrian JC, Gross A and Bernier WE. Use of carbon 16. Nagi M and Takakuda K. Influence of number of dental
dioxide laser in sterilization of endodontic reamers. Oral autoclave treatment cycles on rotational performance of
Surg.: 1980; 49:263–265. commercially available air-turbine handpieces. J Med. Dent.
7. Hurt CA and Rossman LE. The sterilization of endodontic Sci.: 2006; 53:93–101.
hand files. J Endod.: 1996; 22:321–322. 17. Neelakantan P, Cheng CQ, Mohanraj R, Sriraman P, Subbarao C
8. Johnson MA, Primack PD, Lushine RJ and Craft DW. Cleaning and Sharma S. Antibiofilm activity of three irrigation protocols
of endodontic instruments. Part 1. The effect of bioburden activated by ultrasonic, diode laser or Er: YAG laser in vitro.
on the sterilization of endodontic instruments. J Endod.: 1997; Int. Endod. J:2015; 48:602–610.
23:32–34. 18. Parker HH and Johnson RB. Effectiveness of ethylene oxide for
sterilization of dental handpiece. J Dent.: 1995; 23:113–115.
9. Kabbin JS, Shwetha JV, Sathyanarayan MS and Nargarathnamma T.
Disinfection and sterilization techniques of operation theatre: 19. Perakaki K, Mellor AC and Qualtrough AJ. Comparison of an
a review. Int. J Curr. Res.: 2014; 6:6622–6626. ultrasonic cleaner and a washer disinfector in the cleaning
of endodontic files. J Hospital Infect.: 2007; 67:355–359.
10. Linsuwanont P, Parashos P and Messer HH. Cleaning of rotary
nickel-titanium endodontic instruments. Int. Endod. J.: 2004; 20. Rutala WA and Weber DJ. Health care infection control
37:19–28. practices advisory committee. Guidelines for disinfection and
sterilization in health care facilities. cdc.gov/ncidod/
11. Mayur L, Adish S, Ashish M, Deepak J, Sudha M and guidelines/Disinfection.
Rushikesh M. Endodontic instrument sterilization procedures
21. TanomaruFilho MT, Leonardo MR, Bunifacio KC, Dametto FR
followed by dental practitioner. Uniq. J Med. and Dent. Sci.:
and Silva IA. The use of ultrasound for cleaning the surface
2014; 2:106–111.
of stainless steel and nickel-titanium endodontic instruments.
12. Miller C. Tips on preparing instruments for sterilization. Am. Int. Endod. J: 2001; 34:581–585.
J Dent.: 2002; 16:66.
22. Todd RP, Scuott WI and Stephen WG. Microbial
13. Miller CH and Sheldrake MA. Sterilization beneath rings on contamination of endodontic files received from the
dental instruments. Am. J Dent.: 1991; 4:291–294. manufacturer. J Endod.: 2006; 32:649–651.
14. Miller CH. Presence of micro-organisms in used ultrasonic 23. Whitworth CL, Martin MV, Gallagher M and Worthington HV.
cleaning solution. Am. J Dent.: 1993; 6:27–31. A comparison of decontamination methods used for dental
15. Morrison A. Dental burs and endodontic files: Are routine burs. Br. Dent. J: 2004; 197:635–640.
sterilization procedures effective? J Can. Dent. Assoc.: 2009; 24. Zmener O and Spielberg C. Cleaning of endodontic instruments
75:39a–39d. before use. Endod. Dent. Traumat. :1995; 11:10–14.

12

t.me/Dr_Mouayyad_AlbtousH
Chapter
13
Anatomy of
Pulp Spaces

The pulp cavity is the cavity within a tooth, which is

entirely enclosed by dentin, except at apical foramen.
The pulp tissue in the coronal portion is known as pulp
chamber and in radicular portion as the root canal. In
anterior teeth, the pulp chamber gradually merges into
root canal making no distinction. In multirooted teeth,
the pulp cavity consists of a single pulp chamber and
varying number of root canals.
Much of knowledge of anatomy of pulp spaces is
based on the exhaustive work by Hess. The vulcanite
preparation of almost 3000 permanent teeth showed
minute detail of extensions, ramifications and
branching as well as shape, size and number of root
canals in different teeth.
For convenience, pulp space is divided into two: Fig. 13.1 Components of root canal system a. coronal pulp;
a. Coronal pulp (lies within the crown of the tooth) b. radicular pulp
b. Radicular pulp (lies in the anatomic root).
b. Radicular Pulp
a. Coronal Pulp
The portion of pulp tissue from the canal orifice to
The coronal pulp chamber is a box like space apical foramen is the root canal (radicular pulp). It may
surrounded by dentin and located in the anatomical be sectioned as coronal, middle and apical third.
crown. The outer (towards cusps) surface is known as Accessory/lateral canals are branching of main root
‘roof’ and the inner (towards root) is known as ‘floor’. canal. The distinction between an accessory canal and
Influx of the pulp chamber directly under a cusp or a a lateral canal is that lateral canal is a canal that branches
developmental lobe is known as ‘pulp horn’. These pulp to lateral surfaces of the root (usually visible on a
horns can extend just under cusp tips or incisal edges radiograph); whereas, accessory canal is branch of main
in young individuals but as the age advances these canal at apical third/furcation area (usually not visible
become less prominent. The floor of the pulp chamber on radiograph) (Fig. 13.1).
lies perpendicular to the long-axis of the tooth and is The root canal begins as a funnel shaped orifice,
formed as a result of fusion of the diaphragm during generally at the level or slightly apical to the cervical
the development of the tooth. The canal orifices line and ends at the apical foramen. Most canals tend
originate in this pulpal floor. The canal orifices are not to curve in the faciolingual direction. These curvatures
separate structures but are continuous with both pulp can be viewed in a radiograph taken at different angles.
chamber and root canals (Fig. 13.1). The walls of pulp A straight root canal extending the entire length of
chamber derive their names from corresponding walls root is not a common feature. Usually, the canals are
of tooth surfaces, such as the buccal wall of a pulp curved; the curvature may be a uniform curvature of
chamber. entire canal or a sharp curvature of canal near apex.

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 196 Essentials of Endodontics

Double curvature in form of letter ‘S’ may also occur.

Curvature in narrow root canals may be difficult to
negotiate; whereas, curvature of even 30° can be
negotiated in wider root canals.
In most cases, number of root canals corresponds with
number of roots, but a root may have more than one canal.
Relationships of Pulp Chamber to Clinical Crown
Krasner and Rankow (2004) proposed certain anatomic
laws, which correlate the relationships of pulp chamber
to the clinical crown:
• Law of centrality: The floor of the pulp chamber is
always located in the centre of the tooth at the level
of cementoenamel junction (Fig. 13.2). a
• Law of concentricity: The walls of the pulp chamber
are always concentric to the external surface of the
tooth at the level of the cementoenamel junction
(Fig. 13.3a and b).
• Law of cementoenamel junction: The cementoenamel
junction is the most consistent, repeatable landmark
for locating the position of the pulp chamber (Fig. 13.4).
• Law of symmetry:
– First law: Except for maxillary molars, the orifices
of the canals are equidistant from a line drawn
across the floor of the pulp chamber in a direction
from mesial to distal (Fig. 13.5a).
– Second law: Except for the maxillary molars, the
orifices of the mesial canals can be found on a line
perpendicular to a line drawn in a mesiodistal
direction in the middle of floor of the pulp
chamber (Fig. 13.5b).
• Law of color change: The color of floor of pulp chamber
is always darker than the walls (Fig. 13.6).
• Law of orifice location b
– The orifices of root canals are always found at the Fig. 13.3 Law of concentricity: (a) Diagrammatic;
junction of walls and the floor (Fig. 13.7). (b) Clinical

13 Fig. 13.2 Law of centrality (diagrammatic) Fig. 13.4 Law of cementoenamel junction (diagrammatic)

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 Anatomy of Pulp Spaces 197

a b

Fig. 13.5 Law of symmetry (diagrammatic): (a) Orifices are equidistant from the mesiodistal line; (b) Orifices are
perpendicular to the mesiodistal line

Fig. 13.6 Law of color change (dark at floor of pulp Fig. 13.7 Law of orifice location (orifices at the junction of
chamber) wall and the floor)

– The orifices are located at the angles of two walls Dummer et al described the configuration of apical
and the floor, coinciding with the developmental constriction as of following shapes (Fig. 13.10):
fusion lines of the root. • Type A. Typical single constriction.
• Type B. Tapering constriction with the narrowest
Anatomy of Apical-third of Root Canal
portion near the actual apex.
The knowledge of anatomy of apical-third of root canal
• Type C. Constriction followed by another constriction
(Fig. 13.8) is mandatory to carry out successful
(multiconstrictions).
endodontic procedures. The apical root canal anatomy
can be differentiated into three landmarks (Fig. 13.9): • Type D. Long parallel constriction.
A fifth type has also been reported, wherein the canal
a. Apical constriction is completely blocked with secondary denting and/or
The apical constriction is the apical portion of the root cementum.
canal system having the narrowest diameter, usually
referred to as the ‘Minor apical diameter’ or ‘apical stop’. It b. Cementodentinal junction
generally lies 0.5 to 1.5 mm short of the apical foramen. The cementodentinal junction is the meeting point of
Violation of this area by root canal instruments lead to dentin and cementum, where the pulp tissue ends and
postoperative discomfort and also delay healing. The root
canal instrumentation and obturation should be up to this
constriction as it would serve as ‘apical dentin matrix’.
periodontal tissue begins. Due to deposition of
cementum, the location and diameter of the cemento-
dentinal junction differ considerably (Fig. 13.11). The
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Fig. 13.8 Apical-third of root canal: Diagrammatic representation

Fig. 13.9 Root end anaomy diagrammatic: (a) Cementum, Fig. 13.10 Shapes of apical constriction: Type A: Single
(b) apical formation, (c) cementodentinal junction, constriction, Type B: Tapering constriction, Type C: Multiple
(d) minor constriction, (e) root canal, (f) major opening constrictions, Type D: Parallel constriction

13 Fig. 13.11 Location of cementum-dentin junction (CDJ). Level may vary on opposite side of the root canal wall, not
coinciding with the apical constriction

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exact position of the cementodentinal junction can only cementum, which changes the shape and location of the
be determined histologically, but for clinical purpose, foramen. The size of apical foramen vary considerably
it is accepted that it almost coincides with the apical (average size in maxillary permanent teeth is 0.4 mm
constriction (minor apical diameter). The location may and in mandibular permanent teeth is 0.3 mm).
not be the same as apical constriction area; on an
average 1.0 mm short of apical foramen. The diameter ANATOMIC COMPLEXITIES IN ROOT CANAL SYSTEM
of canal at cementodentinal junction vary considerably
in different teeth. 1. Radix Entomolaris and Radix Paramolaris
An extra root present distolingual to mesial root of
c. Apical foramen mandibular molar is termed ‘Radix entomolaris’
The apical foramen is defined as ‘an edge or end that differen- (Fig. 13.13a and b); whereas, additional root at the
tiates the termination of canal to the exterior surface of root’. mesiobuccal side of the distal root of mandibular molar
Apical foramen, also known as ‘major apical diameter’, is called ‘Radix paramolaris’. In case of radix entomolaris,
is an opening at or near the apex of the root, through the extra root is usually smaller, lingually placed and
which blood vessels and nerves of the pulp enter and more curved. It often has a sharp apical hook toward
exit the canal (Fig. 13.12). Generally, the apical foramen the buccal. It has 100% (1-1) canal configuration. The
do not exit at apex (mostly 0.5–1.0 mm offset from canal exits the pulp chamber with a marked lingual
centre), may be mesial, distal, lingual or labial. In young orientation. Radix paramolaris occurs less frequently
incompletely developed tooth, the apical foramen is than radix entomolaris.
funnel shaped, with the wider portion extending Maxillary first molar may have four roots; two
outward known as ‘Blunder buss apex’. At that stage, palatal, mesiobuccal and distobuccal.
the mouth of the funnel is filled with periodontal tissue The two palatal roots (one is normal and the other is
that is later replaced by dentin and cementum. As the supernumerary) are referred to as mesiopalatal or
root develops the apical foramen become narrower and distopalatal. They have also been referred to as ‘radix
farther from the apex. The space between the apical mesiolingualis’ and ‘radix distolingualis’.
constriction and apical foramen takes a hyperbolic
shape that resembles a ‘morning glory’ flower. The Classification
mean distance between major and minor apical Carlsen and Alexandersen (1990) classified radix
diameter (apical foramen and apical constriction) has entomolaris into following four types according to the
been found to be 0.5 mm in young teeth and 0.65 mm location of the cervical part of radix entomolaris:
in older teeth. Type A: Distally located cervical part of radix ento-
Apical foramen is usually asymmetrical. This occurs molaris with two distal root components.
due to functional influences on the tooth, viz. occlusal
stress, tongue pressure, mesial/distal drift, etc. This Type B: Distally located cervical part of radix ento-
leads to exertion of pressure on the surrounding walls, molaris with one distal root component.
subsequently causing resorption and laying down of Type C: Mesially located cervical part.

Fig. 13.12 Anatomy of the apical root

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Type III: Initial curve in the coronal third of the root

canal; second curve beginning in the middle and
continuing to the apical third.
Carlsen and Alexandersen (1991) classified radix
paramolaris into following two types:
Type A: Mesial part of root complex consists of three
cone-shaped macrostructures: Facial, medial and
lingual. It can be separate or non-separate.
Type B: Facial part of the root complex consist of three
cone-shaped structures: central, mesial and distal. It can
be separate or non-separate.
Versiani et al (2012) classified maxillary molars with
two palatal roots into following three types:
Type 1: Palatal roots widely divergent, longer and
tortuous (buccal roots may be ‘cow-horn’ shaped).
Type 2: Palatal roots run parallel to each other and
comparatively shorter.
Type 3: Palatal roots are less divergent and often shorter
Fig. 13.13a Radix entomolaris (preoperative)
than buccal roots.

2. C-shaped Canals
C-shaped canal is one of the important anatomic varia-
tion of root canal system. First documented by Cooks
and Cox (1979), C-shaped canals are so named because
of the cross-sectional morphology of the root canals.
• These are mostly seen in mandibular second molar
followed by other mandibular molars and maxillary
molars respectively (Fig. 13.14a and b).
• Formed due to failure of Hertwig’s epithelial root
sheath to fuse on buccal or lingual root surface,
leading to fusion of mesial and distal root on buccal
and lingual aspect. The C-shaped root may also be
formed by coalescence because of deposition of
cementum in-between.
• Roots with C-shaped canals usually have conical or
square configuration.
• With interrupted/irregular fusion, the two roots stay
connected by an interradicular ribbon.
Fig. 13.13b Radix entomolaris (postoperative) • The shape ‘C’ can be continuous throughout the root
length or two/three distinct canals may be seen in
Type AC: Central location (between distal and the mesial C-shaped groove.
root components).
De Moor et al (2004) also classified radix entomolaris Classification of C-shaped Canals
into following three types based on the curvature of C-shaped canals have been classified by various
the separate radix entomolaris variants in buccolingual authors. The accepted classifications are:
orientation.
a. Melton classification
Type I: Straight root/straight root canal.
13 Type II: Initially curved entrance, which continues as a
straight root canal.
Melton et al (1991) classified C-shaped canals, based
on cross-sectional canal configuration, into three types
(Fig. 13.15).

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Type I (C1): The continuous C-shaped canal from pulp

chamber to the apex without any separation.
Type II (C2): The semicolon shaped canal, where dentin
separates one main distinct canal from a mesial/buccal/
lingual canal.
Type III (C3): Two or more (usually two) discrete and
separate canals.
• Subdivision 1: C-shaped orifice in coronal third, which
divides into two or more canals, joining apically.
• Subdivision 2: C-shaped orifice in coronal third, which
divides into two or more canals from mid-root to
the apex.
• Subdivision 3: C-shaped orifice in coronal third, which
divides into two or more canals from coronal to the
apex.

b. Fan classification
Fan et al (2004) modified Melton’s classification and
categorized C-shaped canals based on anatomic and
Fig. 13.14a C-shaped canal (clinical) radiological appearances.

i. Anatomical consideration (Fig. 13.16)

Category I (C1): Uninterrupted C-shape with no
separation/division.
Category II (C2): Discontinuation of shape ‘C’ (semicolon
shape); angle β should not be less than 60° (Fig. 13.17a).
Category III (C3): Two/three separate canals; both angles
α and β less than 60° (Fig. 13.17b).
Category IV (C4): Only one round/oval canal in the
cross-section.
Category V (C5): Canal lumen not visible (mostly in
apical area only).

Fig. 13.14b C-shaped canal (obturated)

Fig. 13.15 Melton’s classification Fig. 13.16 Fan’s classification (anatomic)

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a
Fig. 13.18 Fan’s classification (radiological)
Fig. 13.17a Measurement of angles for C2 canal. Angle β
is more than 60°. (A and B) End of one canal cross-section:
anywhere along the root surface, they are most
M, middle point of line AD: α, angle between line AM and
line BM; β, angle between CM and DM
prominent at the apical third. They contain shreds of
connective tissue and blood vessels but do not supply
the pulp with collateral circulation.
Accessory foramina are the openings of accessory
and lateral canal on root surface. These openings are
very small; average mean diameter is 6.0–60 μ. The
periodontal vessels curve around the root apex of a
developing tooth and often become entrapped in
Hertwig’s epithelial root sheath with resulting
formation of lateral canals and accessory foramina
during calcification. Lateral canals may also occur in
area of bifurcation or trifurcation of multi-rooted teeth
as a result of entrapment of periodontal vessels during
fusion of parts of the diaphragm that become floor of
b
the chamber. Incidence of lateral canals ranges from
27 to 35% (the apical one-third 70–75%, middle one-
third 12–14% and the cervical one-third 15–18%).
Fig. 13.17b Measurement of the angles for C3 canal. Both
angle α and β are less than 60°. (A and B) End of one canal Minute canals may also be present in the bifurcation
cross-section, (C and D) ends of the other canal cross- or trifurcation area of a multi-rooted tooth as a result
section: M, middle point of line AD: α, angle between line of entrapment of periodontal vessels during fusion of
AM and line BM; β, angle between CM and DM the diaphragm, known as furcation canals.
The following radiological findings indicate the
ii. Radiographic consideration (Fig. 13.18)
presence of accessory/lateral canals:
Type I: Conical or square root with a vague, radiolucent
longitudinal line separating the root into mesial and • Widening of periodontal ligament space in the
distal parts. There are mesial and distal canals that merge middle of root (usually an ovoid radiolucent area is
into a single canal before exiting at the apical foramen. evident at the exit point of accessory canal).
Type II: The two canals are separate all along the root • Bulbous root tip (pulp forming extradentin) is clear
and exit separately. indication of extracanal.
• In oral-shaped root and root canal; if file is not in
Type III: One canal superimposes on the separation line
center, there is possibility of accessory canals.
and the other canal appears to continue to the apex.
• Sudden disappearance of radiolucency also indicates
3. Accessory/Lateral Canals furcated canals.
13 These are minute canals that extend haphazardly from
the radicular pulp to the periodontium. Though found
• Inner curvature of root, mainly at the apical area;
mostly presence of accessory and tortuous canals.

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4. Apical Delta from apex). Incidence varies in other teeth; 16% in

Apical delta refers to a condition where the root canal maxillary premolars (1.0 mm from apex), 52% in
exits through more than one tiny canals, instead of a maxillary premolars at 6.0 mm from apex, 30–40%
single canal. If root canal break-up into many tiny canals mandibular premolars at varying levels from apex.
at the exit point, the complexity is known as ‘Apical delta’. Mehrvarzfar et al (2014) evaluated isthmus
Usually, these canals cannot be observed on radiographs. prevalence, location and types in mesial roots of
mandibular molars in an Iranian population and
5. Isthmus observed as: 83% mandibular molars had isthmus in
An isthmus is a narrow, ribbon-shaped communication mesial root; 90% at 6.0 mm from the apex and 70% at
between the root canals that contains pulp or pulpally 2.0 mm from the apex. They emphasized upon using
derived tissues. A few authors have named it as newer technologies to clean and fill these areas.
‘transverse anastomosis’, ‘corridor’ and simply as Isthmus is of great importance during apicoectomies
‘lateral connection’. Since, the isthmus houses pulpal of molars as well as other teeth. The retrograde cleaning
tissue, it might serve as a potential site for bacterial of these areas is usually difficult; however, with the
growth. Usually isthmuses merge into main canal advent of microultrasonics coupled with better viewing,
within 3.0 mm from the apex. Whenever two canals are these areas are cleaned and obturated for better
present in one tooth, an isthmus should be suspected treatment results.
and attempt should be made to débride the same.
6. Root Canal Curvatures
Classification Root canal curvature is quite common in radicular pulp
Hsu and Kim (1997) classified isthmus into following space. The curvature can be uniform (gradual) in the
five types (Fig. 13.19): entire canal; abrupt curve (sharp curvature) near
Type 1: An incomplete isthmus with a faint communica- the apical half or even S-shaped (double curvature) in the
tion between two canals (barely traceable). middle of root canal (Fig. 13.20).
Type 2: A complete/definite connection between two Root canal curvatures should be determined prior to
canals (may be straight or C-shaped). start of root canal procedures so as to avoid procedural
errors and subsequent failure of root canal treatment.
Type 3: A complete, but short connection between two
Various authors have classified root canal curvatures
canals.
based on their devices to measure the curvature. The
Type 4: An incomplete or complete connection between accepted methods of measuring root canal curvatures
three or more canals. are:
Type 5: Two or more canal openings without any visible
connection. a. Schneider’s Method
Studies have reported higher incidence of isthmus Preoperative radiograph of the concerned tooth is
in mesial root of mandibular molars (80% at 4.0 mm scanned. A midpoint is market at the center of canal

Fig. 13.19 Hsu and Kim’s classification of isthmus

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a b c d

Fig. 13.20 Root canal curvatures: (a) Straight; (b) Minor curvature at apex; (c) Acute curvature in apical area; (d) Double
curvature

orifice as ‘A’. Another point ‘B’ is marked at the b. Weine’s Method

deviation of the canal. A third point ‘C’ is marked at Weine simplified the method by taking long-axis of
the apical foramen. Line AB and BC are joined coronal canal as line AB and long-axis of canal from
intersecting each other. Angle formed by this apex to deviation as CD. The intersection of the two is
angulation (α) is the angle of curvature (Fig. 13.21a). the angle of root canal curvature (Fig. 13.21b).
Based on angle (α), the curvature is classified as:
• Straight: Angle is less than 50°. c. Lutein Method
• Moderately curved: Angle is 5–20°. Lutein modified Schneider method by identifying four
• Severely curved: Angle is more than 20°. geometrical points. Point A is marked at the center of
The double curvatures have also been determined canal orifice and point B is marked 2.0 mm below the
following Schneider’s method; whereby, angle ‘X’ is for orifice along the long-axis of canal. Point A and B are
first curvature and angle ‘Y’ is for second curvature joined and extended. Point C is marked 1.0 mm coronal
(Cunningham and Sonia).

13 Fig. 13.21a Schneider’s method Fig. 13.21b Weine’s method

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 Anatomy of Pulp Spaces 205

Fig. 13.22 Horizontal dimensions of root canal

Fig. 13.21c Lutein method

to the apical foramen. Point D is marked at the apical

foramen and the line CD is joined and extended. The
angle formed by intersection of these two lines is the
angle (α) of curvature. He used the same classification
as of Schneider (Fig. 13.21c).
d. CBCT Imaging
CBCT provides better view of canal morphology as
compared to periapical radiographs (3D imaging of Fig. 13.23 Horizontal dimension of root canal (after obturation)
canal curvature; buccolingual curvatures are better seen
The horizontal dimensions are classified as:
in CBCT imaging).
• Round (maximum initial working width is equal to
A software, provided with CBCT, can measure the
minimum initial working width).
radius of root canal curvatures. The smaller the radius,
• Oval (maximum initial working width is up to two
the greater the curvature; more complexities in pulp
times greater than minimum initial width).
space anatomy. Based on curvature, the canal curvature
is classified as: • Long oval (maximum initial working width is up to four
times more than the minimum initial working width).
Large radius (more than 8.0 mm): Mild curvature
• Flattened (maximum initial working width is more
Intermediary radius (between 4.0 and 8.0 mm):
than four times greater than the minimum initial
Moderate curve
working width).
Small radius (less than 4.0 mm): Severe curvature
• Irregular (unspecified maximum and minimum
A few authors prefer simple terms for curvatures as
working widths).
apical curve, sickle-shaped curve, bayonet curve and
Circumferential filing is preferred to clean and shape
dilacerated curve; and also I (straight), J (apical curve),
the horizontal dimensions of canal spaces.
C (entirely curved) and S (multicurve).
Classifications of Root Canal Anatomy
7. Horizontal Dimensions of Root Canals
The root canal anatomy has been classified by various
Very few studies have documented horizontal status
authors. The accepted classifications are:
of root canals at varying levels of root. Horizontal
dimensions are important parameters, for effective
cleaning and shaping of the canal spaces so as to achieve
successful results (Figs 13.22 and 13.23).
a. Weine’s classification (Fig. 13.24)
Type I: A single root canal extends from the pulp
chamber to the apex (1-1)
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Fig. 13.24 Weine’s classification

Type II: Two separate root canals leave the pulp chamber Type III (1-2-1): One canal leaves the pulp chamber and
and join short of the apex to form one canal (2-1) divides into two in the root; the two then merge to exit
Type III: Two separate canals leaving the chamber and as one canal.
exiting the root in separate apical foramina (2-2) Type IV (2-2): Two separate, distinct canals extend from
Type IV: One canal leaving the pulp chamber but the pulp chamber to the apex.
dividing short of the apex into two separate and distinct Type V (1-2): One canal leaves the pulp chamber and
canals with separate apical foramina (1-2). divides short of the apex into two separate, distinct
canals with separate apical foramina.
b. Vertucci classification (Fig. 13.25)
Type VI (2-1-2): Two separate canals leave the pulp
Type I (1-1): A single canal extends from the pulp chamber, merge in the body of the root, and re-divide
chamber to the apex. short of the apex to exit as two distinct canals.
Type II (2-1): Two separate canals leave the pulp Type VII (1-2-1-2): One canal leaves the pulp chamber,
chamber and join short of the apex to form one canal. divides and then rejoins in the body of the root, and
finally redivides into two distinct canals short of the
apex.
Type VIII (3-3): Three separate, distinct canals extend
from the pulp chamber to the apex.
Gulabivala et al extended the types as follows:
Type IX (3-1): Three separate canals merging into one
at apex.
Type X (2-1-2-1): Two canals join to form one canal,
again bifurcate into two and join at apex (exit as one).
Type XI (4-2): Four separate root canals, merging into
two and existing as two at apex.
Type XII (3-2): Three separate canals, exiting two at apex.
Type XIII (2-3): Two separate canals, bifurcate and exit
on three at apex.
Type XIV (4-4): Four separate canals, exiting separately
at apex.
Type XV (5-4): Five separate canals exiting as four at apex.

13 Fig. 13.25 Vertucci classification

Sert et al added two more types:
Type XVI (1-3): One root canal, bifurcating into three at
apex (exiting as three).

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Type XVII (1-2-3-2): One canal separating to two, than

three and exiting as two at apex.
Peiris et al added another two types:
Type XVIII (1-2-3): One canal bifurcating to two and
exiting as three at apex.
Type XIX (3-1-2): Three canals merge as one in middle
and exiting as two at apex.
Al-Qudah and Awandeh further added four types:
Type XX (2-3-1): Two canals bifurcating into three and
exiting as one at apex.
Type XXI (2-3-2): Two canals bifurcating into three and
exiting as two at apex.
Type XXII (3-2-1): Three canals bifurcating into two and Fig. 13.26 Maxillary central incisor
exiting as one at apex.
Type XXIII (3-2-3): Three canals bifurcating into two configuration can further be referred as 1-1, 2-2, 1-2, 2-
and exiting as three at apex. 1, etc. Accessory canals are shown as A1, A2 etc.

Rather than following the classification system, the variations in CONFIGURATION OF PULP SPACES
root canals should simply be designated as 1-1, 1-2, 2-1, 2-2 IN INDIVIDUAL TEETH
and so on; i.e. the number of canals extending from pulp chamber
(if one: write ‘1’; if two: write ‘2’ and so on) to the number of A. MAXILLARY TEETH
canals exiting from the roots (if one: write ‘1’; if two: write ‘2’
and so on). This becomes 1-1, 1-2, etc. In case it divides further a. Maxillary Central Incisor
in between, the expression can be 1-2-1, 2-1-2, etc. • In labiolingual section, the pulp cavity is pointed near
the incisal edge; wider at the centre and then tapers
c. Ahmed and Dummer classification: Citing limitations
from cervical area up to apex.
of present classification system (Weine and Vertucci),
Ahmed and Dummer (2017) proposed a new classifica- • In mesiodistal section, the pulp cavity is wider in the
tion, describing details of number of roots, root canals, centre, with pulp horns (usually three) extending
their deviation and even presence of accessory canals. towards the incisal area. The canal tapers from
cervical area up to apex (Fig. 13.26).
In Vertucci’s classification, buccal and palatal posts
of maxillary premolars are not specified; for example, • Pulp floor is oval; root canal is continuous with pulp
one rooted maxillary premolar with two separate canal chamber without any distinction.
and double rooted premolar with one canal each are • Cross-section of root canals is ovoid at cervical end;
designed as Type V (2-2). whereas, round in middle and apical area.
The proposed classification describes as number of • Variation includes fusion/germination and dens
tooth (11, 12, 13 etc.), number of roots (113, 213, etc.) invagination.
and number of canals (1142, 214 B1P1, etc.). For example, • Rarely two or more canals present.
symbol 215B1P2 describes as, maxillary second premolar • The configuration of roots, root canals, their devia-
(15), with two roots (215), one canal in buccal root and tions and ramifications, curvatures and inclination,
two canals in palatal root (B 1 P 2 ). These canal etc. are depicted below.

Maxillary Central Incisor

Length of tooth Number of Number Lateral/ Apical Cross-section Root Inclination
roots of root accessory ramifi- of root curvature
canals canals cations
23.3 mm (average) 1 1 20–45% 13–15% Coronal (ovoid) Straight: 75% Mesial-axial: 2%
25.6 mm (maximum) +1 (rare) Middle (round) Distal: 8% Palatal-axial: 10%
21.0 mm (minimum) Apical (round) Mesial: 4%
Labial: 9%
Lingual: 4% 13

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Kasahara et al (1990) evaluated root canal anatomy

of 510 extracted maxillary central incisors after making
them transparent. They observed accessory canals in
60% specimens (branches were usually very small; only
(3%) thicker than the size 40 file). 45% teeth showed
apical foramen away from apex (within 1.0 mm from
the apex). Vast majority of canal were straight
(curvature less than 10°); few were curved towards the
labial surface.
Almeida-Gomes et al (2012) reported a rare case of one-
rooted maxillary central incisor with four root canals.
a b
b. Maxillary Lateral Incisor
• Pulp chamber is similar to maxillary central incisors
but smaller. It has two pulp horns corresponding to
developmental mamelons (pulp horns may be absent).
• Cross-section of root canal at the cervical area is
ovoid (sometimes round); whereas round at middle
and apical area (Fig. 13.27).
• Variation includes fusion/germination, dens
invagination (dens in dente).
• One root and more than one canal or two roots and
two canals may be present.
• Deviation of root canal system is depicted in c
Fig. 13.28a to c. Fig. 13.28a to c Two root canals in maxillary lateral incisor

• The configuration of roots, root canals, their devia-

tions and ramifications, curvatures and inclination,
etc. are depicted below.
Peix-Sachez and Minana-Latiga (1999) reported
maxillary lateral incisor with three canals.
Mupparapu and Singer (2004) reported a rare case
of bilateral dens invagination (dens in dente) in
maxillary lateral incisors (same patient exhibited dens
invagination in mandibular lateral incisor also).
Mohan et al (2012) reported a case of maxillary lateral
incisor with two curved roots and two separate canals.
Lee et al (2013) reported three cases of maxillary lateral
incisors evaluated by CBCT imaging (i) one root and
two canals (ii) two roots and two canals (iii) one root
Fig. 13.27 Maxillary lateral incisor and three canals.

Maxillary Lateral Incisor

Length of tooth Number of Number Lateral/ Apical Cross-section Root Inclination
roots of root accessory ramifi- of root curvature
canals canals cations
22.3 mm (average) 1 1 10–12% 12–15% Coronal (ovoid) Straight: 30% Mesial-axial: 16%
25.1 mm (maximum) +1 (rare) Middle (ovoid) Distal: 53% Palatal-axial: 29%
20.5 mm (minimum) Apical (round) Mesial: 3%

13
Labial: 4%
Bayonet
curve: 6%

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 Anatomy of Pulp Spaces 209

Maxillary Canine
Length of tooth Number of Number Lateral/ Apical Cross-section Root Inclination
roots of root accessory ramifi- of root curvature
canals canals cations
26.0 mm (average) 1 1 20–25% 8–10% Coronal (ovoid) Straight: 39% Mesial-axial: 6%
28.9 mm (maximum) +1 (Rare) Middle (ovoid) Distal: 32% Palatal-axial: 21%
23.1 mm (minimum) Apical (round) Mesial: 0%
Labial: 13%
Lingual: 7%
Bayonet
curve: 7%

11.6% (1-2-1), 2.8% (2-1), 2% (1-2), 1.2% (2-1-2-1) and

0.08% (2-2).
Mupalla et al (2015) reported unusually lengthy
canine (31 mm) with two separated root canals (labial-
palatal canal orifice) which joined at the apical third
(2-1 configuration).

d. Maxillary First Premolar

• In the labiolingual section, pulp horn usually extend
farther incisally under the buccal cusp as latter is
usually better developed than the lingual cusp.
• In mesiodistal section, pulp horns appear blunt and
pulp chamber is in continuation with the root canals.
Fig. 13.29 Maxillary canine
(Fig. 13.30).
• Root canals are generally curved in apical third area.
c. Maxillary Canine • Cross-section in cervical area is ovoid or kidney-
• Pulp chamber wider labiolingual than mesiodistal, shaped; whereas, slight ovoid in mid-root and round
without any pulp horns. in apical area.
• Cross-section at cervical area is oval labiolingually. • Apical end of roots may be nearing maxillary sinus
It is also oval-shaped in middle and round at the (thin bony separation); judicious instrumentation is
apical area (Fig. 13.29). advised.
• Variation includes two roots and two root canals; • The incidence of one canal is 10–15%.
roots may be dilacerated and presence of dens • Mostly two canals are present (80%) and the
invagination (dens in dente). possibility of third canal is 0.5–1.0%.
• The configuration of roots, root canals, their • Deviations of root canal system of maxillary first
deviations and ramifications, curvatures and premolar are depicted in Fig. 13.31a and b.
inclination, etc. are depicted below.
A number of studies have reported two canals in
maxillary canines.
Shin et al (2011) reported a case of maxillary canine
evaluated with CT scans, showing two separated root
canals (root canals also showed communication at the
mid-point).
Nagesh and Sharat (2011) reported single root canal
morphology of 250 permanent maxillary canines using
CBCT imaging. They observed 81.6% samples exhibited
1-1 canal configuration; 11.6% (1-2-1), 2.8% (2-1), 2%
(1-2) and 1.6% (2-1-2-1).
Nikhita et al (2014) studied root canal morphology
of 250 permanent maxillary canines using CBCT
imaging. They observed 81.6%, 1-1 canal configuration, Fig. 13.30 Maxillary first premolar
13

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 210 Essentials of Endodontics

Fig. 13.31a Three canals in maxillar y first premolar Fig. 13.31b Three canals in maxillar y first premolar
(diagnostic) (obturated)

Maxillary First Premolar

Length of tooth Number of Number of Cross-section Root Inclination
roots root canals of root curvature
21.8 mm (average) 1 Root: 1-1: 8–10% Coronal (ovoid) Single root Distal-axial: 10%
23.8 mm (maximum) 20–30% 2:1: 1–1.5% Middle (ovoid) Straight: 38% Buccal-axial: 6%
18.8 mm (minimum) 2 Roots: 1–2: 72% Apical (round) Distal: 37%
50–75% 3–3: 6% Labial: 15%
3 Roots: Lingual: 3%
0–6% Double root
Buccal
Straight: 28%
Distal: 14%
Labial: 36%
Bayonet
curve: 8%
Palatal
Straight: 45%
Distal: 14%
Labial: 9%
Lingual: 9%

• The configuration of tooth roots, root canals, their • In majority of cases, a single canal is present. Two
deviations, curvatures and inclination, etc. are canals are also prevalent in 30% cases.
depicted above. • The pulp chamber is large and is continuous with
Pecora et al (1991) studied internal anatomy of 240 the canal. At the cervical level, the pulp cavity is
extracted maxillary first premolars and observed single elliptical and wide buccolingually (Fig. 13.32).
canal in 17.1%, two canals in 80.4% and three canals in
• As first premolar, the apical third of the root may
2.5% cases.
curve considerably to distal (rarely to buccal).
e. Maxillary Second Premolar • Deviations of root canal system of maxillary second
• The occlusal pulp chamber is similar to that of the premolar are depicted in Fig. 13.33a and b.
• The configuration of tooth roots, root canals, their
13 first premolar, but the pulpal canal floor is deeper.
Buccal and palatal pulp horns present (buccal pulp
horn is larger).
deviations, curvatures, inclinations, etc. are depicted
as follows.

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 Anatomy of Pulp Spaces 211

Maxillary Second Premolar

Length of tooth Number of Number of Cross-section Root Inclination
roots root canals of root curvature
21.0 mm (average) 1 Root: 1-1: 8–10% Coronal (ovoid) Straight: 9.5% Distal-axial: 6%
23.0 mm (maximum) 20–30% Middle (ovoid) Distal: 27% Lingual-axial: 21%
19.0 mm (minimum) 2 Roots: 2-1: 5% Apical (round) Mesial: 16%
50–75% 1-1: 5% Labial: 12.7%
3 Roots: 2-2: 72% Lingual: 4%
0–6% 3-3: 6% Bayonet
curve: 20.6%

Fig. 13.32 Maxillary second premolar Fig. 13.33b Maxillary second premolar with three canals
(obturated)

Udaykumar and Sumitha (2010) studied root canal

morphology of 200 maxillary second premolars in an
Indian population and observed 1-1 canal configuration
in 29.2%; 2-1 in 33.6%; 2-2 in 31.1% and 2-1-2-1 in few
cases. They also observed apical deltas in 14% and
isthmi in 19% samples studied.

f. Maxillary First Molar

• The maxillary first molar has three separate roots:
two buccal and one palatal. The roots may be straight
or slightly curved at the apical area (mesiobuccal
distally curved; distobuccal, distal/mesial curved
and palate curved buccally). Any root can have an
extra canal, prevalence is more in the mesiobuccal
root. The palatal canal is wider than either of the
Fig. 13.33a Maxillary second premolar with three canals
(diagrammatic) buccal canals (Fig. 13.34). The palatal orifice is largest,
round or oval in shape and is easily accessible for
exploration. It lies near the central pit, mesial to
Pecora et al (1992) studied internal anatomy of 300 oblique ridge. Mesiobuccal orifice lies under mesio-
maxillary second premolars. They observed one canal buccal cusp and is longer buccopalatally. The orifice
in 90.3% cases; two canals in 32.4% and three canals in of a fourth canal (extra MB) may be present (Fig. 13.35a
0.3% of the samples studied (one root was present in to c) mesial-palatal to the main orifice or lie on a line

13
90.3% and two roots in 9.7%). A predominance of root drawn from the main mesiobuccal orifice to the
curvature towards distal was also observed (similar to palatal orifice. Distobuccal orifice is located slightly
first). distal and palatal to the mesiobuccal orifice.

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Fig. 13.34 Maxillary first molar

Fig. 13.36a Maxillary first molar with eight canals (see canal
orifices)

Fig. 13.35a Location of fourth canal (MB2)

Fig. 13.36b Maxillary first molar with eight canals (diagnostic)

Fig. 13.35b MB2 Fig. 13.35c MB3

• Each root has one canal mostly; the pulp chamber is

in mesial half of the tooth.
• Deviations of root canal system of maxillary molars
are depicted in Fig. 13.36a to c.

13 • The incidence of anomalies have been reported by

many authors in their case reports.
– Four rooted maxillary molars (Christie, 1991) Fig. 13.36c Maxillary first molar with eight canals (obturated)

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 Anatomy of Pulp Spaces 213

– Two palatal canal in three rooted teeth (Stone 1981, the canal along that depression (thin dentin wall
Hartwell, 1982) along that area).
– Two palatal canals and two palatal roots (Baratto- • The incidence of two canals in mesiobuccal root is
Filho, 2002) 55% and one canal 45%. With the use of microscopes,
– Three palatal canals in one root (Maggiore et al 2002) the studies have reported higher percentage of
– Root fusion second mesiobuccal canal.
 Fusion of palatal and distobuccal root (De Moor, • In distobuccal root, one canal is prevalent in 94% of
2002) teeth and in palatal, it is more than 99%.
 Fusion of mesiobuccal and distobuccal root • The selected studies as regard root canals in mesio-
(Fava, 2001) buccal root of maxillary first molar is summarized
• C-shaped canals (Danker et al 1990) in Table 13.1.
• Two canals in distobuccal root (Hulsmann, 1997) • The configuration of tooth, roots, root canals,
• 41% maxillary first molars have three root canals; their deviations and curvatures, etc. are depicted
56% four canals and 3–4% more than four root canals, below.
6, 7 and 8 canals have also been reported in literature Ahmad and Al-Jadaa (2014) reported three root
(pulp chamber is triangular, if three canals present and canals in mesiobuccal root of maxillary first molars (two
rhomboidal, if four or more canals present). case reports). They observed 1.3–2.4% maxillary first
• Mesiobuccal root has concavity on one side (usually molar had three canals in mesiobuccal root (3-2 canal
distal). Judicious instrumentation is mandatory in configuration is common).

Table 13.1 Mesiobuccal root and root canals (selected studies)

Author Type of Number of One canal Two canals One apical Two apical
(year) study teeth studied (%) (%) opening (%) openings (%)
Vertussi (1984) Vitro 100 45 55 82 18
Pineda and Kutler (1972) Vitro 262 39.3 60.7 51.50 48.50
Caliskan et al (1995) Vitro 100 34.4 65.6 75.4 24.60
Imura et al (1998) Vitro 42 19 80.9 11.80 88.20
Weine et al (1999) Vitro 293 42.0 58 66.20 33.80
Sert and Bayirli (2004) Vitro 200 6.5 93.5 60.50 37.50
Neaverth et al (1987) Clinical 228 19.3 80.3 35.60 64.40
Slowey (1974) Clinical 103 49.6 50.4 — —
Wolcott et al (2002) Clinical 1193 39.0 61.0 — —
Stropko (1999) Clinical 1096 26.6 73.2 45.10 54.90
Zactar et al (1997) Clinical 133 59.4 40.6 85 15

Maxillary First Molar

Length of tooth Number of Number of Root curvature
roots root canals
Mesiobuccal Distobuccal Palatal 2 roots: 3 Canals: 41% Palatal Mesial Distal
19.9 mm 19.4 mm 20.6 mm 4–5% 4 Canals: 56% Straight: 40% Straight: 21% Straight: 54%
(average) (average) (average) 3 roots: 5 Canals: 2.5% Mesial: 4% Distal: 78% Mesial: 19%
21.6 mm 21.2 mm 22.5 mm 95% More than 5 Distal: 1% Bayonet: 1% Distal: 17%
(maximum) (maximum) (maximum) Four roots: canals: 10% Buccal: 55% Buccal : 1%
18.2 mm 17.6 mm 17.6 mm 2–3% Canals in
(minimum) (minimum) (minimum) C-shaped: mesiobuccal
0.10% root:

13
1-1: 41%
2-1: 40%
2-2: 19%

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g. Maxillary Second Molar

• Maxillary second molar is similar to first molar with
slight difference, such as short and closer roots
with comparatively less curvature. It is usually
three rooted; however, four rooted, two rooted and
even single rooted are also prevalent. Fusion of root
is also common; with or without merging of root
canals.
• The root canals can be three as in first molar and
two or one depending upon the number of roots.
Extra canals can also be present in any root, usually
prevalent in mesiobuccal root.
• Pulp chamber is usually triangular (Fig. 13.37).
Mesiobuccal canal orifice lies under the mesiobuccal
cusp (the orifice is more towards mesiobuccal side Fig. 13.38 Maxillary second molar (location of canals)
as compared to first molar). The distobuccal orifice
lies midway between mesiobuccal and palatal
orifices. The palatal canal orifice lies on the palatal Fontana et al (2012) reported unusual maxillary
aspect of the root (Fig. 13.38). second molar with four roots and two independent
palatal canals (incidence of extrapalatal canal has also
• Taurodontism and C-shaped canals are common. been reported in literature).
• Being closer to maxillary sinus (roots almost touching Badole et al (2012) reported maxillary second molar
the floor), pulpal diseases may cause sinusitis and with four roots and four canals (two independent
sinusitis may lead to discomfort in these teeth. palatal canals: mesiopalatal and distopalatal).
• The configuration of tooth roots, root canals, their Zhang Q et al (2014) reported 42.25% maxillary
deviations and curvatures, etc. are depicted below. second molars with fused roots; a total of 187 samples
studies 22 samples showed partial canal merging and
6 as complete merging of root canals.

h. Maxillary Third Molar

• Anatomically, it resembles second molar (length
decreases from first to third molar).
• The number of roots in maxillary third molar ranges
from one to five; corresponding canals range from
one to six.
• Prevalence of second canal in mesiobuccal root (MB2)
in maxillary third molar range from 35–40% (25%
MB2 show 2-1 canal configuration and 15% show
Fig. 13.37 Maxillary second molar 2-2 canal configuration).

Maxillary Second Molar

Length of tooth Number of Number of Root curvature
roots root canals
Mesiobuccal Distobuccal Palatal 3 Roots: 55% 1 Canal : 2–4% Palatal Mesial Distal
20.2 mm 19.4 mm 20.8 mm 2 Roots: 2 Canals: 8–10% Straight: 63% Straight: 22% Straight: 54%
(average) (average) (average) 40–45% 3 Canals: 60% Buccal: 37% Distal: 1% Mesial: 17%
22.2 mm 21.3 mm 22.6 mm 1 Root: 1–2% 4 Canals: 30% curve curve curve
(maximum) (maximum) (maximum) Four roots: Canals in mesio-
18.2 mm 17.5 mm 19.0 mm 1–2% buccal root

13
(minimum) (minimum) (minimum) 1-1: 63%
2-1: 13%
2-2: 24%

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Maxillary Third Molar

Length of tooth Number of Number of Root curvature
roots root canals
Mesiobuccal Distobuccal Palatal 3 Roots: 50% 3 Canals: 50% Palatal Mesial Distal
18.5 mm 18.10 mm 19.2 mm 2 Roots: 45% 2 Canals: 38% Straight: 80% Straight: 60% Straight: 80%
(average) (average) (average) 1 Root: 5% 1 Canal: 2% Curved: 20% Curved: 40% Curved: 20%
[4th canal (MB2)
in less than 40%:
2-1: 25%
2-2: 15%

• The distobuccal and palatal roots in three rooted

maxillary third molar presents single root canal (1-1
type).
• Lateral canals have also been reported in 1.0–15%
maxillary third molars.
• The pulp chamber can be triangular with three canal
orifices, or rhomboidal with 4 or 5 root canal orifices
or a conical chamber with only one root canal (shows
great variation in configuration of pulp chamber).
• Usually tipped to distobuccal side; creates problem
in access opening.
• The root canal anatomy of maxillary third molar and
obturation is depicted in Fig. 13.39a and b.
• The configuration of tooth, roots, root canals, their
deviations and curvatures, etc. are depicted above. Fig. 13.39b Maxillary third molar (obturated)
Pecora et al (1992) observed MB2 canals in maxillary
third molar as: 68% 1-1 canal configuration; 14%, 2-2 B. MANDIBULAR TEETH
and 18%, 2-1 canal configuration. A few authors have
a. Mandibular Incisors (Central and Lateral)
reported only 20% MB2 in mesiobuccal root of maxillary
third molars. • The incisors are mostly single rooted; root may be
curved distobuccally.
• The root canal is usually rounded mesiodistally and
slightly flat in labiolingual direction (Figs 13.40 and
13.41).

Fig. 13.39a Maxillary third molar (preoperative) Fig. 13.40 Mandibular central incisor
13

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 216 Essentials of Endodontics

Fig. 13.41 Mandibular lateral incisor

• The mandibular incisors may have second root canal

(40% incidence). Mostly two root canals join at apex
Fig. 13.42a Two root canals in mandibular incisors (diagnostic)
(2-1 type). Rarely two separate canals (2-2 type).
• Mandibular incisors are lingually tilted (lateral
incisors are also distally tilted).
• Cross-section at cervical area is oval; whereas, it is
ribbon-shaped in midroot and round in apical third
area.
• Deviations of root canal system of mandibular
incisors are depicted in Fig. 13.42a and b.
• Fusion, germination and dens invagination are the
possible anatomical variations.
• The configuration of tooth roots, root canals, their
deviations, curvatures and inclination, etc. are
depicted in boxes.
Sikri and Sikri (1992) studied root canal morphology
of mandibular incisors by radiographic evaluation and
reported that 4.16% central incisors and 5.52% lateral
incisors exhibited two root canals. 35.42% root canals
in central incisors were curved and 39.13% canals were
curved in lateral incisors. Fig. 13.42b Two root canals in mandibular incisors (obturated)

Mandibular Central Incisor

Length of tooth Number of Number of Cross-section Root Inclination
roots root canals of root curvature
21.5 mm (average) 1 1-1: 70% One canal Straight: 60% Mesial-axial: 2%
23.4 mm (maximum) 2-1:40% Coronal (ovoid) Distal: 23% Lingual-axial: 29%
19.6 mm (minimum) Middle (ovoid) Labial: 13%
Apical (round)
Two canal
Coronal (ovoid)
Middle (round)

13
Apical
(round and curve
toward incisal)

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Mandibular Lateral Incisor

Length of tooth Number of Number of Cross-section Root Inclination
roots root canals of root curvature
22.4 mm (average) 1 1-2: One Canal Straight: 60% Mesial-axial: 17%
24.6 mm (maximum) 55–60% Coronal (ovoid) Distal: 23% Lingual-axial: 29%
20.2 mm (minimum) 2-1: Middle (round) Labial: 13%
14–16% Apical (round)
Two canal
Coronal (ovoid)
Middle (round)
Apical: (round
and curved
toward incisal)

Al-Fourzan et al (2012) studied incidence of two

canals in extracted mandibular incisors of Saudi
Arabian population and observed 70% teeth showing
1-1 canal configuration and 30%, 2-1 configuration.
Kabak et al (2007) reported a case exhibiting two
canals in four mandibular incisors.

b. Mandibular Canine
• Mostly single rooted; root may curve distobuccally.
Rarely two roots present.
• Mostly single canal; rarely two canals present
(Fig. 13.43a to d).
• Pulpal chamber is narrow mesiodistally; pulp floor
Fig. 13.43e Mandibular canine
is oval (Fig. 13.43e).
• Fusion and dens invagination have been reported.
• Cross-section at cervical area is ovoid funnel-shaped;
whereas, ovoid in midroot and round in apical third
area.
• The configuration of roots, root canals, their devia-
tions tooth, curvatures and inclination, etc. are
depicted below.
Shemesh et al (2016) evaluated root anatomy and root
canal morphology of 1981 mandibular canines in Israeli
population using CBCT imaging. They reported 1.9%
a b c d cases had bifurcated roots and 10.3% bifurcated root
Fig. 13.43a to d Mandibular canine with two root canals canals.

Mandibular Canine
Length of tooth Number of Number Lateral/ Cross-section Root Inclination
roots of root accessory of root curvature
canals canals
25.5 mm (average) 1 root: 1-2: 9.5% Coronal (ovoid) Straight: 68% Mesial-axial: 13%
27.5 mm (maximum) 95–99% 92–96% Middle (ovoid) Distal: 20% Lingual-axial: 15%
22.9 mm (minimum) 2 roots: 2-2: Apical (round) Mesial: 1%

13
1–5% 4–8% Labial: 7%
Bayonet
curve: 20%

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Pecora et al (1993) studied internal anatomy, direction • Usually one rooted; 2–3 roots may be present (root
and number of roots and size of human mandibular may be curved distobuccally).
canines and observed 98.3% as one rooted and 1.7% • Incidence of bifurcated canals varies considerably
two rooted canines. 92.2% presented with one canal (3–60%).
(1-1); 4.9% with 2-1 type canal and 1.2% with 2-2 type • Pulp chamber wider buccolingually.
canal configuration. • In single canal, the outline is oval; it is round in two
Nikhita et al (2014) studied root canal morphology or more root canals.
of 250 permanent mandibular canines using CBCT • Gemination, fusion and dens invagination are
imaging. They observed 79.6% teeth exhibited 1-1 canal common variations.
configuration; 13.6% (1-2-1), 3.2% (2-1), 2% (1-2) and
• Deviations of root canal system of mandibular first
1.6% (2-1-2-1).
premolars are depicted in Fig. 13.45a to e.
Holtzman (1997) reported a rare case of mandibular
• The configuration of tooth, roots, root canals, their
permanent canine with three root canals.
deviations, curvatures and inclination, etc. are
c. Mandibular First Premolar depicted below.
• It is documented that mandibular first premolar is Slowey (1979) has observed that mandibular first
the most difficult tooth to be treated endodontically. premolar are probably the most difficult teeth to be
treated endodontically due to wide variation in root
• The mandibular first premolar resembles canine; the
canal morphology. The incidence of two or more root
cingulum simulates the lingual cusp (Fig. 13.44).
canals in first premolar has been reported to be as low
• The mesiolingual developmental groove makes the
as 2.7% and as high as 62.5%.
tooth asymmetrical.
Sikri and Sikri (1994) studied mandibular premolars
• The crown is lingually tilted by 45°. The distal
by radiographs and cross-sections and reported that
inclination is approximately 10°. The bifurcated root
29.5% of mandibular first premolars and 13.5%
canals are quite prevalent in first premolar.
mandibular second premolars exhibited second root
canal. They also found C-shaped canals in 10% of
mandibular first premolar. According to them ovoid
shape of canals was most prevalent at cervical third
area, while canals became round at middle and apical
third area.
Caliskan et al (1995) examined the root canal morpho-
logy of 100 mandibular premolars and observed as:
64.15% (1-1), 7.5% (2-1), 3.77% (1-2-1), 7.55% (2-2), 9.43%
(1-2), 1.89% (2-1-2), Nil (1-2-1-2), 5.66% (3-3).
They also observed that 52.33% of mandibular first
premolars had lateral canals and 16.98% had transverse
anastomosis.
Tzu-Yi et al (2006) studied root canal morphology of
Fig. 13.44 Mandibular first premolar 82 mandibular first premolars in a Chinese population

Mandibular First Premolar

Length of tooth Number of Number Lateral/ Cross-section Root Inclination
roots of root accessory of root curvature
canals canals
22.1 mm (average) 1 Root: 98% 1-1: 52.33% Coronal (ovoid) Straight: 48% Distal-axial: 14%
24.1 mm (maximum) 2 Roots: 73–5% Middle (ovoid) Distal: 35% Lingual-axial: 10%
20.1 mm (minimum) 1–2% 2-1: Apical (round) Labial: 2%
3 Roots: 6.5% Lingual: 7%
0–0.5% 2-2: Bayonet

13
19.5% curve: 7%
3 Canals:
5%

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and observed single canal in 54% samples; 22% having

two canals and 18% presented with C-shaped canal
configuration.
Parekh et al (2011) studied root canal morphology
and variations of 40 mandibular first premolars and
observed 20% (1-1), 5% (2-1), 5% (1-2-1), 25% (2-2),
12.5% (1-2) and 2.5% (2-1-2) canal configuration.

Fig. 13.45c Mandibular first premolar with three canals

(preoperative)

Fig. 13.45a Mandibular first premolar with two canals

(diagnostic)

Fig. 13.45d Diagnostic

Fig. 13.45b Obturated Fig. 13.45e Obturated

d. Mandibular Second Premolar • Incidence of second root canal is 12–15%.

• The mandibular second premolar can be of three • Pulp chamber wider buccolingual (lingual pulp horn
cusp type or two cusp type. larger than first premolars).
• The crown is distally and lingually inclined, though • Cross-section at cervical area is ovoid bucco-
not as much as the first premolar. Lingual pulp horn lingually; ovoid in midroot and round in apical third
area (Fig. 13.46).
13
is quite prominent.
• Usually single rooted; root may be curved to disto- • Deviations of root canal system of mandibular
buccally. second premolar are depicted in Fig. 13.47a to d.

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 220 Essentials of Endodontics

Fig. 13.46 Mandibular second premolar

Fig. 13.47c Mandibular second premolar with curved

(C-shaped) canal (preoperative)

Fig. 13.47a Mandibular second premolar with two canals

(diagnostic)

Fig. 13.47d Obturated

• The configuration of tooth, roots, root canals, their

deviations, curvatures and inclination, etc. are
depicted below.
Parekh et al (2011) studied root canal morphology
and variations of 40 mandibular second premolars and
observed 80% samples exhibited 1-1 canal configura-
tion, 2.5% (2-2) and 17.5% (1-2). Other types of canal
Fig. 13.47b Obturated configurations were not observed.

Mandibular Second Premolar

Length of tooth Number of Number Lateral/ Cross-section Root Inclination
roots of root accessory of root curvature
canals canals
21.4 mm (average) 1 Root: 99% 1-1: 55% Coronal (ovoid) Straight: 39% Distal-axial: 14%
23.7 mm (maximum) 2 Roots: 85–90% Middle (ovoid) Distal: 40% Lingual-axial: 10%
19.1 mm (minimum) 0–0.5% 2-1: Apical (ovoid) Labial: 10%

13
3 Roots: 1.5–2.5% Lingual: 3%
0–0.1% 2-2:10–12% Bayonet curve: 7%
3 canals: 0.5% Trifurcation: 1%

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 Anatomy of Pulp Spaces 221

e. Mandibular First Molar • The selected studies as regards aberrant root canal
• Mandibular first molar generally has two distinct anatomy of mandibular first molar is tabulated in
roots, one mesial and the other distal. Three canals Table 13.2.
are usually present: one in distal root and two in • Deviations of root canal system of mandibular first
molar are depicted in Fig. 13.49a and b.
mesial root, i.e. mesiobuccal and mesiolingual.
• A rare case of mandibular first molar with one root
• The buccolingual section reveals that the pulp canal is depicted in Fig. 13.49c to e.
chamber is in the centre of the crown and that the • The configuration of tooth, roots, root canals,
distal canal is ribbon-shaped; whereas, the mesial their deviations and curvatures, etc. are depicted
canals are rounded and thin (Fig. 13.48). below.

a b

Fig. 13.48 Mandibular first molar: (a) Three canals; (b) Four canals; (c) Five canals

Mandibular First Molar

Length of tooth Number of Number of Root curvature
roots root canals
Mesial Distal 2 Root: 98% Mesial Distal Mesial Distal
20.9 mm 20.9 mm 3 Roots: 2% 2-1: 40.5% 1-1: 75% Straight: 16% Straight: 74%
(average) (average) 2-2: 59.5% 2-2: 30% Distal: 84% Distal: 21%
22.7 mm 22.6 mm 2-1: 60% Mesial: 5%

13
(maximum) (maximum)
19.1 mm 19.2 mm
(minimum) (minimum)

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 222 Essentials of Endodontics

Table 13.2 Aberrant root canal anatomy of mandibular first molar (selected cases)
Author (year) study Extra root canals
Stroner et al (1984) 3 Roots: 2 canals in mesial root
In vivo study 2 canals in distobuccal root
1 canal in distolingual root
(five distinct foramina)
Friedman et al (1986) 4 roots (one mesial and three distal)
In vivo study Two root canals in mesial root and one each in distal roots
(five distinct foramina)
Ricucci (1997) 5 canals; three separate mesial and two merging distal
In vivo study (four foramina)
Reeh (1998) 7 canals; four mesial and three distal
In vivo study
Mortman and 6 canals; three in mesial and three in distal root
Singhee (2003)
In vivo study
Lee et al (2006) 5 canals; two mesial and one each in three distal roots
In vivo study
Lee et al (2010) 5 independent canals in mesial root with varying configuration
In vivo study
Yesilsoy et al (2009) 5 canals; three canals in mesial and one each in two distal roots
In vivo study (five distinct foramina)
Faramazi et al (2010) Three distinct canals in mesial root
In vivo study

a b

Fig. 13.49a and b Aberrant canal anatomy (mandibular first molar)

13 c d

Fig. 13.49c to e Mandibular first molar with one root canal

e

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 Anatomy of Pulp Spaces 223

Navarro et al (2007) evaluated third canal in the

mesial root of permanent mandibular first molars in
his review of literature and three clinical case reports.
They reported 13% mesial roots presented third canal.
Earlier studies, as reviewed, have observed 1.0–15%
third canal in mesial root.
de Pablo et al (2010) in their systematic review of root
anatomy and canal configuration of the permanent mandi-
bular first molar comprising 18,781 teeth from 41 studies
observed as: 13% of samples showed third root; 61.3%
three canals, 35.7% four canals, and 1% showed five canals.
Root canal configuration of mesial root revealed two
canals in 94.4% and three canals in 2.3% cases; whereas,
distal root revealed one canal in 62.7%, and rest two
canals (14.5% 2-1 and 12.4% 2-2 canal configuration).

f. Mandibular Second Molar

• The second molar is inclined more lingually than the
first molar; therefore, the access preparation should
a b
correspond to the tilt of the tooth (Fig. 13.50).
• Intercanal communications more common in distal
root than mesial root.
• Maximum variations usually seen in mesial canals.
• 5.0–6.0% mandibular second molars exhibit lateral
canals; mostly in middle third of root.
• C-shaped canal configuration has been reported in
1.0–10% cases (a few studies have shown up to 50%).
• Deviations of root canal system of mandibular
second molar is depicted in Fig. 13.51a to d. c
• The configuration of tooth, roots, root canals and
Fig. 13.50 Mandibular second molar: (a) Three canals;
curvatures, etc. are depicted below.
(b) Four canals; (c) Two canals
Neelakantan et al (2010) studied root and canal
morphology of mandibular second molars in an Indian
canals, 3% single canal and 34% four canals. Most
population and observed as: 87.8% had two roots with
common canal configuration noted was 2-1 in mesial
three canals, 7.5% had C-shaped canal morphology.
root and 1-1 in distal root.
2-2 type canal configuration was common in mesial root
and 1-1 in distal root. Nur et al (2014) evaluated root canal morphology of
Jahromi et al (2013) examined 100 intact human mandibular permanent molars in a south-eastern
mandibular second molars in Iranian population as Turkish population using cone beam tomography. They
regard their roots and root canal morphology. They reported 0.01% mandibular second molars had three
observed 89% two rooted, 6% one rooted and 3% three roots. 90% mesial roots had two canals and 10% one
rooted teeth. 54% teeth exhibited three canals, 6% two canal. 97% distal root had one canal and 3% two canals.

Mandibular Second Molar

Length of tooth Number of Number of Root curvature
roots root canals
Mesial Distal One root: 10% Mesial Distal Single root Mesial Distal
20.9 mm 20.8 mm Two roots: 90% 1-1: 13% 1-1: 92% Straight: 53% Straight: 27% Straight: 58%
(average) (average) 2-1: 49% 2-1: 5% Distal: 26% Distal: 61% Distal: 18%
22.6 mm 22.6 mm 2-2: 38% 2-2: 3% Lingual: 2% Buccal: 4% Buccal: 4%

13
(maximum) (maximum) Bayonet: 19% Bayonet: 7% Bayonet: 6%
19.2 mm 19.0 mm
(minimum) (minimum)

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 224 Essentials of Endodontics

a b

c d

Fig. 13.51 Mandibular second molar: (a) Preoperative; (b) Diagnostic; (c) and (d) Obturated

g. Mandibular Third Molar • In double rooted mandibular third molars, mesial

• The pulp chamber of mandibular third molar root may have canal configuration as 1-1, 2-1, 2-2
anatomically resembles pulp chamber of mandibular and 1-2; whereas, distal root usually exhibit 1-1 canal
first and second molars. It is large and possesses configuration.
many anomalous configurations such as C-shaped • In single rooted teeth, mesial root canal presented
root canal orifices. similar canal configuration (1-1, 2-1, 2-2 and 1-2) and
• Displays most irregular canal configuration. distal canal exhibiting 1-1 canal configuration.
• The mandibular third molar usually has two roots • A few authors have reported rare occurrence of 1-2-
and two canals, but occasionally one root and one 1 type and even 2-5-1 type canal configuration.
canal or three roots and three canals are present (may
• Mandibular third molar with type II canal anatomy
have one to four roots and one to six root canals).
is depicted in Fig. 13.52.
• The alveolar socket of mandibular third molar may
project onto lingual plate of mandible. The apex of • Treated impacted third molar is depicted in Fig. 13.53.
root may be in close proximity to mandibular canal. • The configuration of tooth roots, root canals and
• Mesial inclination of tooth makes the access easier. curvatures, etc. are depicted below.

Mandibular Third Molar

Length of tooth Number of Number of Root curvature
roots root canals
Mesial Distal One root: Mesial Distal Single root Mesial Distal
18.5 mm 18.2 mm 21% 1-1: 59% 1-1:95% Straight 80% Straight 34% Straight 92%
Two roots: 2-1: 19% 2-1: 3% Curved 20% Curved 66% Curved 8%
73% 1-2-1: 15% 1-2-1: 2%
Three roots: 2-2: 2% In three root

13
5.5% 1-2: 6% canals 1-1
type most
prevalent

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 Anatomy of Pulp Spaces 225

a b

Fig. 13.52 Mandibular third molar (type II canal anatomy): (a) Preoperative; (b) Obturated

a b

Fig. 13.53 Impacted mandibular third molar: (a) Preoperative; (b) Obturated

Kuzekanani et al (2012) studied root canal morpho-

logy of 150 mandibular third molars in an Iranian
population and observed as: 73% samples with two
roots, 21% had one root and 5.5% had three roots. 60%
mesial root and 95% distal root had single canal. Other
types 2-1 (19%), 1-2-1 (15%), 2-2 (2%) were reported in
mesial root.
Sidow et al (2000) studied root canal morphology of
150 human mandibular third molars and observed as:
77% had two roots (one to six root canals); 17% one
root (40% contain two canals); 5% three roots and 1%
four roots. 2.2% root canals were C-shaped.

DEVELOPMENTAL ANOMALIES AND ROOT CANAL

a b
SYSTEM
The common developmental anomalies affecting root
canal system are:
1. Dens invaginatus: Dens invaginatus, also known as
dens-in-dente (invaginated odontome) is a develop-
mental anomaly resulting from infolding of the crown
before calcification has occurred. Usually anterior teeth
are involved; mostly prevalent in maxillary central
incisors (Fig. 13.54a to d). Three types of Dens invagi-
natus have been recognized (Oehler’s classification):
c d

Fig. 13.54a to d Dens invaginatus

13

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 226 Essentials of Endodontics

Type 1: Lined by enamel that occurs within the crown; bud to divide, with a resultant formation of either a
not extending beyond cementoenamel junction (CEJ). large tooth with a bifid crown or two completely
Type 2: Enamel lined sac that invades the root and may divided teeth throughout the crown and root (Fig. 13.56).
connect with pulp. Complete: Resulting in the formation of a wide tooth
(crown and root).
Type 3: Extending up to root and opens in the apical
Incomplete: Resulting in union only at the crown or root.
region; no connection with pulp.
Fused teeth may contain separate canals or may share
2. Dens evaginatus: It appears as an accessory cusp on a common canal. The canals may be separated in
occlusal surface of premolars; rarely on molars and coronal aspect and then unite into a common canal in
incisors. Mostly it is located in between buccal and radicular area or vice versa.
lingual cusps of premolars. This globule of enamel Depending upon the developmental stage of this
(accessory cusp) may pose difficulties in root canal union; owing to the usual existence of combined pulp
treatment procedures. chamber in fused teeth, a modified access preparation
is required, (wider mesiodistally).
3. Fusion and gemination: Fusion and gemination are
two different anomalies with almost identical appea- 4. Talon cusp (Eagle’s talon): Talon cusp is a super-
rance. Fusion is identified as the union of two normally numerary structure projecting from the dentinoenamel
separated tooth buds with the resultant formation of a junction to a variable distance towards the incisal edge
joint tooth with confluence of dentin (Fig. 13.55a and b). of an anterior tooth. It consists of enamel, dentin and
Gemination is recognized as an attempt of a single tooth variable amount of pulp (there is a deep developmental
groove where the Talon’s cusp blends with the sloping
lingual tooth surface that consists of pulp horns). Mostly
present on the palatal aspect but few cases have been
reported with talon cusp present on the facial aspect of
the teeth. It is commonly found in permanent maxillary
lateral incisors and deciduous maxillary central incisors.
5. Dilaceration: The term ‘dilaceration’ refers to an
angulation or a sharp curve of 90° or even more in the
root or the crown of a fully grown tooth, mainly caused
due to trauma during tooth development. A few
authors have opined that other factors, such as
hereditary factors and effect of related anatomical
structure (maxillary sinus and mandibular canal) are
the causative factors than trauma. The curve may occur
a b
anywhere along the length of the tooth. Most affected
Fig. 13. 55 (a) Fusion (diagrammatic); (b) Fusion (radiological) teeth are third molars followed by upper lateral incisors.
Roots tend to curve in a distal direction and/or in
lingual direction. Root dilacerations may also occur in
more than one plane (distolingual direction).
The root canal treatment of dilacerated roots is always
challenging. The basic guidelines of unobstructed,
straight line access are followed during access
preparation. The coronal flaring is also helpful before
initiating apical preparations (Fig. 13.57a and b).
The flexible, small files are preferred in narrow canals
[stresses exerted on file (not sharp curves) may lead to
its separation]. The selected files are precurved and
moved slowly along the curvatures.
The curved canals can be obturated with lateral

13 Fig. 13.56 Gemination (diagrammatic)

compaction technique using flexible Ni-Ti spreaders,
which can penetrate greater depths as compared to
stainless steel spreaders.

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 Anatomy of Pulp Spaces 227

a b

Fig. 13.57a and b Dilaceration

Prevalence of dilacerations have been found to

be higher in mandibular third molars ranging from
3.0–30% and in maxillary molars (1.3–8.5%).
6. Taurodontism: A tooth anomaly characterized by the
enlargement of the pulp chamber, which may reach the
proximity of the root apex. In this condition coronal portion
is enlarged at the expense of the roots (Fig. 13.58a to d).
A taurodont may appear as a normal tooth. The tooth
is usually rectangular in shape rather than tapering
towards the roots. The long rectangular shape of the d
pulp chamber seems to cause difficulty in locating the Fig. 13.58 Taurodontism: (a) Normal anatomy; (b) Taurodont
orifice of the canal and subsequent difficulties in (diagrammatic); (c) Preoperative (radiological); (d) Taurodont
instrumentation and obturation. Taurodontism may be (obturated)
associated with periodontal problems.
8. Dentinogenesis imperfecta: Dentinogenesis imperfecta
7. Palatal developmental groove: It originates from the
cingulum of the maxillary incisors (mostly lateral
incisors) and ends apically at various levels of root.
implies partial (type 1) or complete (type 2) oblitera-
tion of pulp chamber and root canals by continued
formation of dentin.
13

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 228 Essentials of Endodontics

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52. Kottoor J, Murugesan R and Albuquerque DV. A maxillary
lateral incisor with four root canals. Int. Endod. J.:2012;
45:393–397.
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70. Mupaparapu M and Singer SR. A rare presentation of dens
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concurrently with bilateral maxillary dens invaginatus: 87. Purra AR, Mushtaq M, Robbai I and Farooq R. Spiral
Case report and review of literature. Aust. Dent. J.:2004; computed tomographic evaluation and endodontic manage-
49:90–93. ment of a mandibular second molar with four roots. A case
71. Muppalla JN, Kavuda K, Punna R and Vanapatla A. report and literature review. Iran Endod. J.:2013; 8:69–71.
Management of an unusual maxillary canines: A rare entity. 88. Raj UJ and Mylswamy S. Root canal morphology of maxillary
Case Report in Dent.:2015; Article ID 780908. second premolars in an Indian population. J. Conserv.
72. Navarro LF, Luzi A, Garcia AA and Garcia AH. Third canal Dent.:2010; 13:148–151.
in the mesial root of permanent mandibular first molars: 89. Reeh ES. Seven canals in a lower first molar. J. Endod.:1998;
review of literature and presentation of 3 clinical reports 24:497–499.
and 2 in vitro studies. Med. Oral Patol. Oral Circ. 90. Ricucci D and Siqueira JF Jr. Fate of the tissue in lateral canals
Buccal.:2007; 12:e605–9. and apical ramifications in response to pathologic conditions
73. Nayak G, Aeran H and Singh I. Radix mesiolingualis and and treatment procedures. J. Endod.:2010; 36:1–15.
radix distolingualis: a case report of a tooth with an unusual 91. Ricucci D. Apical limit of root canal instrumentation and
morphology. Restor. Dent. Endod.:2016; 41:322–331. obturation, part 1:literature review. Int. Endod. J.:1998;
74. Neelakantan P, Subbarao C, Ahuja R, Subbarao CV and 31:384–393.
Gutmann JL. Cone-beam computed tomography study of root 92. Rodrigues E, Braitt HA, Galvao BF Leal da Silva EJ. Maxillary
and canal morphology of maxillary first and second molars first molar with 7 root canals diagnosed using cone-beam
in an Indian population. J. Endod.:2010; 36:1622–1627. computed tomography. Rest. Dent. Endod.:2016.
75. Neelakantan P, Subbarao C, Subbarao CV and Ravindranath 93. Ross IF and Evanchik PA. Root fusion in molars: incidence
M. Root and canal morphology of mandibular second molars and sex linkage. J. Periodontol.:1981; 52:663–667.
in an Indian population. J. Endod.:2010; 36:1319–1322. 94. Sadeghi S and Poryousef V. A novel approach in assessment
76. Nishant J and Bhuyan AC. Maxillary first molar with eight of root canal curvature. I.E.J.:2009; 4:131–134.
canals: A case report. identistry-the journal:2011; 7:35–38. 95. Sempira HN and Hartwell GR. Frequency of second
77. Nur BG, Ok E, Altunsoy M, Aglarci OS, Colak M and Gungor mesiobuccal canals in maxillary molars as determined by
E. Evaluation of the root canal morphology of mandibular use of an operating microscope: a clinical study. J.
permanent molars in a south-eastern Turkish population Endod.:2000; 26:673–674.
using cone-beam computed tomography. Eur. J. Dent.:2014; 96. Sert S and Bayrl G. Taurodontism in six molars: a case report.
8:154–159. J. Endod.:2004; 30:601–602.
78. Olson DG, Roberts S, Joyee AP, Collins DE and McPherson 97. Sert S, Sahinkesen G, Topen FT, Eroglu SE and Oklay EA.
JC. Unevenness of the apical constriction in human maxillary Root canal configuration of third molar teeth. A comparison
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79. Parekh V, Shah N and Joshi H. Root canal morphology and Endod. J.:2011; 37, 109–117.
variations on mandibular premolars by clearing technique: 98. Sidow SJ, West LA, Liewehr FR and Loushine RJ. Root canal
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study of root canal anatomy of maxillary second premolars. 99. Sikri V and Sikri P. Mandibular premolars: Aberrations in
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82. Pecora JD, Woelfel JB and Sousa Neto MD. Morphologic 101. Sikri VK and Sikri P. Root canal morphology of mandibular
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Dent.J.:1991; 2:45–50. 102. Sikri VK. Aberrant root canal anatomy of human permanent
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84. Peix-Sanchez M and Minana-Laliga R. A case of unusual 104. Silva EJ, Nejaim Y, Silva AV, Haiter-Neto F and Cohenca N.
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evaluation by optical microscopy. J. Endod.:2003; 29:
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107. Teixeira FB, Sano CL, Gomes BP, Zaia AA, Ferraz CC and canals. Compend. Contin. Educ. Dent.:1996; 17:1028–1032,
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preliminary analysis of the morphology of lateral canals after morphology of mandibular first premolars and the location
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110. Verma P and Love RM. A Micro CT study of the mesiobuccal 118. Yesilsoy C, Porras O and Gordon W. Importance of third
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a micro-computed tomography study. J. Endod 2012; 38, H. Detection of the second mesiobuccal canal in
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Endod. J.:2005; 38:124–128.
112. Vertucci FJ. Root canal morphology and its relationship to
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Chapter
14
Access Cavity
Preparation

Endodontic treatment may help the patient retain a i. Pain Management

clinically jeopardized tooth that would otherwise be Pain and dentistry are considered synonymous. Pain
destined for extraction. However, it greatly depends in any form and severity must be dealt with carefully
on the ability of operator to achieve successful results before initiating endodontic procedures. Pain may be
thereby maintaining the tooth in its physiological due to inflammatory conditions, neurovascular/
position with form and functions. neuropathic disorders, musculoskeletal and/or
The operator must have the knowledge of the odontogenic problems. An effective strategy for pain
internal anatomy of teeth and the possible variations management is proper diagnosis, drugs, followed by
before undertaking endodontic therapy. It has been specific treatment. In any case, it is important to
established that the root with a normal tapering canal determine whether the pain originates from tooth or is
and a single apical foramen is an exception. Any tooth referred from another tissue (non-odontogenic). Pain
may have extra root and any root may have extra root relieving drugs, premedication/sedatives and local
canal, accessory canals, communicating canals, fins, anesthesia can be useful in relieving pain. Details of
deltas, loops, etc. Thorough knowledge of the drugs used in endodontics are given in Chapter 4.
complexity of root canal system is mandatory to carry
out thorough cleaning and shaping and hermetic ii. Sterilization (Asepsis)
obturation; subsequently, the successful outcome of the Understanding and following infection control
treatment. Access cavity design and preparation is procedures are very important prior to endodontic
imperative for successful endodontic treatment and also treatment. Cross-infection (spread of microorganisms
prevention of iatrogenic problems, which usually leads from one patient to another) should be managed by
to failure. Recently, the trend of endodontic access proper disinfection and sterilization. Aseptic environ-
cavity preparation is being shifted from traditional ment coupled with sterilized instruments is mandatory
(based on operator needs) to conservative preparation for successful endodontic treatment. The general
(based on dentin support and structural strength of guidelines of handwashing, use of gloves, masks and
tooth). It is established that treatment failures are mostly protective glasses, etc. should be followed religiously.
because of structural compromises of the tooth. With Details of sterilization and infection control are given
the advent of modern endodontic techniques coupled in Chapter 12.
with panoramic viewing with operating microscope
iii. Drainage-Trephination
and better illumination, the access cavity preparation
is dictated by the morphology of individual pulp Incisions and drainage are the most effective way to
chamber and the availability of dentin around the pulp control pain associated with abscess formation in the
spaces of the tooth being treated. apical tissues. The abscess can be drained via root canals
or through surrounding soft tissues. Drainage through
root canal is preferred, being convenient and it also
BASIC PRINCIPLES OF ENDODONTIC TREATMENT minimizes patient’s anxiety. Drainage lead to ease out
Basic principles of endodontic treatment are to be the pus and increase in pH of surroundings; and
followed before initiating root canal treatment in any subsequently, lead to reduction in pressure by allowing
tooth. The principles are: accumulated gases to escape.

232

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 Access Cavity Preparation 233

Trephination (fistulation) involves creating a surgical

passage in the root apex. It provides a channel for
the escape of pus, which subsequently relieves the
accumulated pressure. The detailed procedure is
described in Chapter 23.

iv. Immobilization
Immobilization implies stabilizing the tooth (teeth) to
be endodontically treated so as to minimize trauma to
the periodontal ligament. It is established that
traumatized teeth are more susceptible to infection and
the inflamed tissues yield easily to trauma.
The concerned tooth can be splinted or should be
‘hold’ with fingers during endodontic procedures. It is
good practice to relieve occlusion in all endodontic cases
Fig. 14.2 Root canal file aspirated (arrow)
because it lessens the possibility of hurting the
periodontal ligament. Before use of burs for access
cavity preparation or use of rotary instruments during Advantages
canal preparation, immobilizing the tooth will certainly • Provide clean surgical field
lead to better success of endodontic treatment. • Protect patient from ingestion or aspiration of
v. Isolation (Rubber Dam Application) endodontic instruments (Fig. 14.2)
Isolation of teeth under treatment is mandatory for • Facilitate retraction of soft tissues
successful endodontic outcome. Isolation creates an • Protect tongue, lips and cheeks from cutting action
aseptic field and also protect the patient and the of burs
operator from inadvertent mishaps during endodontic • Operator and team is protected from splash of saliva;
procedures. S. Barnum introduced the idea of using subsequently the infection
rubber dam to keep the teeth dry during operative/ • Provides better visibility
endodontic procedures. The rubber dam as an isolation
• Both patient and the operator feel comfortable
armamentarium has become indispensable in endo-
dontics (Fig. 14.1). • Reduces risk of cross-infection, significantly reducing
Over the years the trend of using rubber dam has the microbial content of aerosols.
increased. The simplicity of its placement has Use of rubber dam should be avoided in certain cases,
encouraged practitioners and endodontists to use such as:
rubber dam in routine. Patients are also aware of the • Asthmatics and mouth breathers as they may not
advantages and insist on using rubber dam. tolerate the dam
• Partially erupted and malpositioned teeth; difficult
to receive a retainer (clamp)
• Patient may not allow placement of a rubber dam
because of psychological reasons
• Patients allergic to latex (non-latex rubber dam in
also available).

Armamentarium
A rubber dam kit (Fig. 14.3) should have the following
items:
a. Rubber dam sheets: Available in the form of rolls from
which requisite sheets can be cut; individual sheets

Fig. 14.1 Rubber dam applied over mandibular first

molar
are also available (Fig. 14.4) with the following
characteristics:
Size: 5 × 5′′, 6 × 6′′, 5 × 6′′
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 234 Essentials of Endodontics

The modified/recently introduced rubber dam sheets

are:
• Hygiene dental dam: It is a non-latex rubber dam for
patients with latex allergy. This is powder-free
synthetic material (6 × 6′′ size and medium gauge
thickness).
• Derma dam: It is a non-latex and powder-free rubber
dam. It provides sufficient resistance during use in
endodontic procedures.
• Flexi dam: It is an elastic, non-latex dental dam (can
be elongated 1000% before tearing). It is also powder-
free, reducing the chances of allergic reaction. It is
available in blue and violet colors, providing good
Fig. 14.3 Rubber dam kit contrast to the operating area.
b. Rubber dam clamps (retainers): These are used to
secure the dam to the teeth that are to be isolated
(Fig. 14.5). A retainer has two jaws connected by a bow.
On each jaw, two prongs are present which means that
there are four prongs in a clamp. Each prong rests on
the mesial/distal line angle of the tooth to be clamped.
A prong should not extend beyond the angle of the
tooth otherwise it would interfere with the placement
of a wedge or matrix band during restoration. Certain
retainers have inverted prongs, i.e. directed gingivally;
preferred in partially erupted teeth.
Two types of retainers are:
i. Winged retainers: These retainers have wing like
projections on the outer aspect of their jaws. Hence,
they provide extra retraction of the rubber dam
from the field of operation. The wings are passed
through the punched hole in the dam and then the
dam and the retainer placed together onto the
concerned tooth. After placement, the dam is
Fig. 14.4 Rubber dam sheet slipped carefully over the wings onto the tooth.

Thickness
Thin: 0.006′′
Medium: 0.008′′
Heavy: 0.010′′ (provides better retraction of soft tissue
and are more resistant to tearing)
Extra heavy: 0.012′′
Special heavy: 0.014′′
Color: Available in several colors, but green and blue
colors are preferred because they provide good
contrast with the surroundings. Rubber dam sheet
has a shiny side and a dull side. The dull side should
14 face the operator so as to reduce any light reflected
from it. Fig. 14.5 Rubber dam clamps

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 Access Cavity Preparation 235

ii. Wingless retainers: These have no wings on their

jaws, i.e. they are smooth on their outer aspect. The
retainer is first placed on the tooth and then the
dam is stretched over the clamp onto the tooth.
Several clamps are available. The larger clamps are
used for adult patients and the smaller ones for
children. Newer clamps have also been introduced
(with modified wings and jaws), such as:
Tiger clamp
• The clamp has serrated jaws
• Used mainly for partially erupted and structurally
compromised teeth.
Silker-Glickman clamp (S-G clamp) Fig. 14.7 Rubber dam frame
• Extended wings facilitate rubber dam placement
around teeth with minimal tooth structure. Newer frames, as given below, have been introduced
providing improved functioning.
Haller clamp
• Hold tongue and cheek and improve the impression Nygaard Ostby frame (Shark mouth frame)
making. • Radiolucent nylon frame; polygonal in shape.
Cushee clamp Articulated frame
• Increases patient comfort (avoid contact of steel • Foldable plastic frame (polysulfone), facilitate endo-
clamp with gingiva and tooth). dontic radiography (a double hinge in the vertical
• Enhances rubber dam seal to limit leaking from axis of the frame facilitates its folding).
above or below the dam.
Derma frame
c. Retainer forceps: The retainer forceps holds the • Pliable metal frame; can be bent to take radiographs.
retainer and facilitates its placement and removal from
Safe-T frame
the tooth (Fig. 14.6).
• Two piece frame design; provides secure fit without
d. Rubber dam frame: It holds borders of the dam and stretching the rubber dam sheet. The raised edges of
position the dam as required. The frame is U shaped, the frame provide barrier, preventing fluids from
usually made of metal or plastic. The metal one is escaping onto the patient.
known as the Young’s frame. Plastic frame is useful
when a radiograph is to be taken without removing e. Rubber dam punch: It is a punch for making holes in
the frame (Fig. 14.7). The frame has minute projections the dam and is characterized by a rotating metal disc,
on its outer surface where the dam is secured. An which bears five or six holes of different sizes, and a
additional two hooks may be present on the sides of sharp pointed plunger (Fig. 14.8). When the handle of
the frame. The frame is preferably placed beneath the the punch is pressed, the plunger should rest in the
dam rather than above it. The commonly used frames center of the hole. If not, the plunger tip would get
are metal frames with plastic caps on the ends to protect
the patient’s skin and eyes.

Fig. 14.6 Retainer forceps Fig. 14.8 Rubber dam punch

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 236 Essentials of Endodontics

a b

Fig. 14.9a and b Rubber dam template

damaged compromising its cutting ability. The holes

are of different sizes according to the size of different
teeth. Appropriate hole should be used for particular
tooth, otherwise the dam may tear during its placement.
e. Rubber dam template: The positions of the teeth
are marked and are used to transfer these markings
to the rubber dam sheet for the holes to be punched
(Fig. 14.9a and b).
f. Dental floss: A strand of dental floss (Fig. 14.10)
should be tied around the retainer before it is carried
into the oral cavity. This is a safety measure to prevent Fig. 14.10 Dental floss tied with the retainer
accidental aspiration of the clamp. Floss should be
passed through both the holes in the jaws and around
the bow of the clamp. The floss should be adequately
long, say twelve inches, so that the strand hangs out of
the mouth for a sufficient distance. Dental floss may
also be used for passing the rubber dam sheet through
interproximal contact.
g. Wedjet: An elastic cord generally used to secure the
dam around teeth away from the clamp (Fig. 14.11). It
can also be used to push the dam through the inter-
proximal contact. Rarely, it is used as a retainer instead
of a clamp.
h. Lubricant: A lubricant aids in passing the dam over

14 the tooth. It is applied on both sides of the dam in the

area of punched holes. Lubricants may be commercially
available; alternatively soap, vaseline, shaving cream, Fig. 14.11 Wedjet elastic cord

t.me/Dr_Mouayyad_AlbtousH
 Access Cavity Preparation 237

etc. can also be employed. Vaseline or petroleum jelly d. Optidam

should also be applied on the patient’s lips and corners • Available in anterior and posterior versions.
of the mouth to avoid constant irritation from the rubber • 3-D anatomically contoured design; allows easy
dam. placement and accommodates anatomical variations
in the oral cavity. Very comfortable for the patient.
New Rubber Dam • Can be autoclaved in routine.
a. Instidam • Minimal tension on the clamp due to its design.
• Made of translucent natural latex that is very stretch- • Powder free dam; reduces the chance of air borne
able, tear resistant and provides easy visibility. particles that can cause an allergic reaction.
• Compact design fits outside the patient’s mouth. e. Dry dam
Comfortable to the patient. • An alternative type of rubber dam, which does not
• Built in flexible frame, with prepunched hole off- require a frame
center by half an inch. (Prepunched hole helps • Fits like a face mask
eliminate tearing and additional holes may be • Absorbent lining provides comfort to the patient
punched if necessary.) • Non-allergic
• Radiographs may be taken without removing the • Useful in anterior teeth; not good for posterior teeth
dam by bending the Instidam to one side. • Not useful during bleaching.
• Produces minimal pull on clamp.
f. Flexi dam (Fig. 14.13)
• Single use only. • It is non-latex flexi dam available with built-in frame
b. Handidam: Handidam is a preframed rubber dam; • Good tear resistance and is odorless
easy to place on the patient and saves time. • Plastic frame provides requisite comfort to the
patient.
c. Optra dam (Fig. 14.12)
• Available in two sizes: Regular and small. Alternative Rubber Dams
• Anatomical shape and integrated frame make a. Kool dam: It is a light cured material applied on
placement fast and easy. gingiva and adjacent teeth prior to power bleaching
and sand blasting providing the requisite isolation.
• Flexible in all directions; comfortable for patient for This is also known as liquid rubber dam. It is flexible,
long duration procedures. showing good tear resistance and is easy to remove.
• Both arches are fully exposed and provide easier It is user friendly rubber dam substitute (Fig. 14.14).
access to the treatment field. Opal dam, a resin based product, is not used these
• Metal clamps are not required. days because the heat produced during curing of
• Can be kept in place during radiography. resin cause discomfort/pain to the patient.
b. Fast dam: Fast dam can be anatomically shaped
providing requisite dry field for the operator. All
saliva ejectors can be adjusted with the suction holes
provided along the perimeter. It effectively retracts

Fig. 14.12 Optra dam Fig. 14.13 Flexi dam

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 238 Essentials of Endodontics

Fig. 14.14 Kool dam

Fig. 14.16 Isolite

• If the clamp is attached to the rubber sheet before it

is carried to the oral cavity, ligation with dental floss
to prevent the clamp from being swallowed is not
necessary.
• Having the rubber already stretched over the frame
makes it easier to mount it symmetrically and reduces
the application time.
The routinely used techniques for rubber dam
application are:
Fig. 14.15 Fast dam a. Bow technique: The bow technique can be employed
without an assistant. It provides a good view of the
oral cavity as the clamp is being placed. A disadvantage
the tongue and the cheeks, maintaining a continuous
is that the rubber must be stretched over the wings,
dry field (Fig. 14.15).
which may lead to its tear. The largest punch should
c. Isolite: A new device, provides illumination, retrac- be used for making the hole to avoid tearing.
tion, isolation and throat protection. It has soft and
flexible mouthpiece, which isolates maxillary and b. Wing technique: In this technique the rubber dam is
mandibular quadrants simultaneously, providing to be inserted along both wings of the clamp into the
isolation and the illumination (Fig. 14.16). It is hole punched in the dam. The preliminary steps can be
preferred in young patients with incompletely accomplished by the assistant and the placement is
erupted teeth. completed by the operator. The assistant inserts the
The disadvantage of this device is being more selected clamp into the hole in the rubber sheet at an
expensive than rubber dam, not providing the color angle of 45° with the bow towards the distal, relative
contrast and may damage gingiva (isolite does not to the dental arch. Then the attachment to the rubber
seal the gingiva from irrigants and intracanal dam frame is carried out stretching the rubber
medicaments). diagonally.
The disadvantage of this technique is the reduced
Rubber Dam Application
14 There are many methods for applying the rubber dam.
The important features are:
visibility, especially on the more distal teeth. In
addition, care must be taken not to pinch or injure soft
tissues, such as tongue, lips, or cheeks. As the clamp is

t.me/Dr_Mouayyad_AlbtousH
 Access Cavity Preparation 239

carefully placed into undercut areas of the tooth, the hole may be spread wider with the fingers, and the
patient is instructed to signal if there is any discomfort rubber is pulled down around the tooth. The clamp is
in the gingiva. Once the rubber dam is released from then placed over the isolated tooth (Fig. 14.17a and b).
the wings of the clamp, the placement is completed. The advantage of this procedure is that all types of
clamps can be used and the visibility is better.
c. Rubber sheet first technique: The rubber dam clamp
and forceps should be kept ready and the rubber sheet d. Clamp first technique: The clamp is placed first on
is stretched over the frame. A special rubber dam is the tooth. The clamp-forceps and rubber sheet-frame
provided with frame, which has guiding grooves for a should be kept ready (Fig. 14.18a to e). The order in
saliva ejector at the lower right and left borders. The which they are brought into the oral cavity is reversed.
next step is fitting of the clamp. If it fits well, the rubber It is essential that the clamp be secured against the
dam attached to frame is carried to the oral cavity. The possibility of its slipping into the pharyngeal cavity.

a b
Fig. 14.17a and b Rubber sheet first technique

a b c

14
d e

Fig. 14.18 Placing rubber dam: (a) Punching hold in rubber dam sheet; (b) Application of lubricant; (c) Placement of
rubber dam sheet over the clamp; (d) Evaluation of rubber dam placement; (e) Completion of rubber dam placement

t.me/Dr_Mouayyad_AlbtousH
 240 Essentials of Endodontics

This is accomplished by looping a long piece of dental • Select a rubber dam clamp depending on the type of
floss over the bow of the clamp and letting it hang out the tooth to be isolated. A clamp forcep is used to
of the mouth where it can be quickly grasped in case of seat the clamp onto the tooth first on the lingual
emergency. The problem generally, faced during cervical region then onto the buccal cervical region.
placement of the rubber dam in that the hole must be Before trying the clamp onto the tooth, dental floss
stretched wide to pass over the selected clamp. is tied around it. The length of the floss should be
Therefore, the use of wingless clamps is recommended such that it hangs outside the mouth for a sufficient
because the smaller width makes it less susceptible to distance.
tear. The advantage is the unobstructed view as the • Take a rubber dam sheet. Punch a hole on its upper
clamp is being applied. right corner or mark it with ‘R’ for identifying the
In a few cases, the techniques described above will patient’s right side. The sheet is then placed on a
have to be modified in order to achieve a well-placed, template and the position of the holes are marked
tightly fitting rubber dam. Patients with fixed ortho- with a pen.
dontic appliances pose problems. In such situations, it • A lubricant is then applied on both sides of the
is possible to place a rubber dam by using dental floss punched hole to facilitate the passage of dam over
ligatures (Fig. 14.19). Teeth with fixed prostheses may the tooth. The patient’s lips and corners of the mouth
need endodontic treatment. If only single tooth is are also coated with a lubricant (Fig. 14.20).
involved, it is better to remove the crown to obtain a
• The rubber dam is placed on the tooth and passed
better view. If the underlying tooth is severely
through the contact. The rubber dam sheet is
damaged, it may be necessary to attach the dam to the
stretched at the lips of the hole before insertion. Once
adjacent teeth or to employ a clamp designed especially
it has passed through the contact, the contact is
for deeply damaged teeth.
sufficient to hold the sheet back.
The final step for all the techniques is to disinfect
the operating field. Chlorhexidine/betadine are suitable • The rubber dam is similarly passed around each
disinfecting agent for dental use. tooth one by one, until the desired number of teeth
have been isolated.
Rubber dam placement: The steps involved in rubber • The rubber dam is unfolded and spread neatly.
dam placement are: Slowly and steadily the dam is hooked to the
• Attain a comfortable patient position. Remove projections on the frame while making sure there are
calculus, overhanging restorations, etc. minimal folds in the dam. The frame should be
• Check for tightness of the proximal contacts by placed beneath the dam.
passing the floss obliquely from buccal or lingual
• A low volume evacuator tip may be passed through
side. Tight proximal contacts would not allow the
an extra hole made in the dam into the lingual sulcus
passage of rubber dam; immediate separation may
and allowed to remain there throughout the
be carried out to facilitate easy placement of rubber
procedure. A high volume evacuator tip on the other
dam.
hand is placed above the rubber dam for intermittent
suctioning throughout the procedure.

14 Fig. 14.19 Crossing contact with dental floss Fig. 14.20 Applying vaseline to patient’s lips

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 Access Cavity Preparation 241

ACCESS CAVITY PREPARATION

The main objective of preparing an access cavity is to
detect the root canal orifices for further penetration into
the canal system. This will in turn avoid potential
complications, which are likely to confront in the way
of successful treatment.
Before considering root canal treatment in any tooth,
the accessibility of that tooth needs to be ascertained.
An extremely malpositioned tooth, very limited mouth
opening and uncooperative patients may compromise
the outcome of treatment.
The main aim of the design of the cavity, ‘access
cavity’, is to provide straight-line approach to the apical
foramen. Access cavity preparation implies the creation
of a space from occlusal table to canal orifice(s) so as to
facilitate instrumentation, irrigation and obturation of
the root canals. This is so significant in root canal
therapy that it is described as ‘gateway to success’. The Fig. 14.21 Avoid access from proximal surface
access preparation should allow proper débridement
of the pulp chamber and introduction of the root canal
instruments without any obstruction.

Objectives of Access Cavity Preparation

• To gain direct access to the apical foramen (not
merely to the canal orifices).
• To facilitate removal of pulp tissue from coronal as
well as radicular spaces.
• To facilitate instrumentation of the canal spaces,
subsequently preparing and obturating the canals.
• To maintain structural integrity of the tooth (conserve
as much tooth structure as possible).
Points to Remember
Fig. 14.22 Evaluation of radiograph (see pulp chamber,
• The rubber dam should be placed onto the concerned
roots and periodontal condition)
tooth and the adjacent tooth for better visibility.
• The initial entry should be made either through
occlusal or lingual surface but never through
proximal surface [approaching the pulp chamber and
the canals through the proximal surface may lead to
ledge formation and/or even breakage of the
instruments. And also, by doing so, the pulp tissue
in the coronal aspect remains untouched, which leads
to failure (Fig. 14.21)].
• The radiograph should be evaluated for overall
configuration of the pulp chamber and the root
canals and also the inclination of the roots in the jaws
(Fig. 14.22).
• During ‘reading’ the radiograph, if the radiolucency
abruptly vanishes or diminishes in size, a bifurcation
of the canal is suspected (Fig. 14.23). Another
radiograph at an angle of 20–30° mesial/distal can
help confirming the bifurcation.
Fig. 14.23 Abrupt diminishing the root canal indicates
bifurcation of the canal
14

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 242 Essentials of Endodontics

permanent filling material (preendodontic build-up).

Then the normal access cavity is prepared through
the occlusal or lingual surface.
• All unsupported cusps must be reduced to obtain a
definite clearance in occlusal and lateral movement.
This decreases the chances of cuspal fracture or even
the vertical fracture of root.
• The access cavity should have a certain amount of
a b
resistance form to ensure that the tooth does not
Fig. 14.24 (a) Removal of caries; (b) Defective restoration, fracture during treatment as well as retention form
prior to instrumentation to allow a proper coronal seal of the restorations
(both interim and permanent).
• Caries and defective restorations should be
thoroughly removed, even compromising the loss Armamentarium for Access Cavity Preparation
of tooth structure (Fig. 14.24a and b). The following armamentarium is usually required for
• Periodontal status should also be evaluated and access cavity preparation of any tooth:
managed accordingly.
a. Magnification and Illumination
Rules for Access Cavity Preparation The preparation of an ideal access cavity preparation
• The entry is to be achieved to gain direct access to requires the use of magnification and an appropriate
the apical foramina, not merely to the canal orifices. light source. A number of adjuncts, like the microscope,
The cavity is widened so as to remove remnant of dental loupes, endoscopes and orascopes, etc. can aid
the coronal pulp, which can be source of infection the clinician to locate canal orifices and also the calcified
even after the treatment. Straight line access is and additional canals. Transilluminating devices are
important for better instrumentation, irrigation and preferred to visualize floor of the pulp chamber.
subsequently obturating the canals. No conservative
approach is followed at the cost of non-negotiation b. Handpieces
of the root canal. The pulp chamber must be free of A high-speed handpiece can be used for most phases
necrotic pulp remnants. of access cavity preparation. A slow-speed handpiece
• Access cavity preparations are different from can be used in cases where increased tactile awareness
occlusal cavity preparation used in operative is required like in teeth with calcified and receded pulp
dentistry. The principle of occlusal preparation is chambers.
based on the topography of occlusal grooves, pits
and fissures. The access cavity preparations are c. Burs and Diamond Points
designed for uncovering the roof of the pulp chamber i. Endo access kit is provided by different companies,
and providing direct access to the apical foramina containing set of burs required to initiate, open and
through root canals. prepare access cavity in any tooth. Inverted cone
• Before starting the access preparation, radiographs bur is used for initial nick followed by round burs
taken from at least two different angles must be for the initial entry into the pulp chamber of anterior
evaluated to know the possible deviation of internal teeth.
anatomy. After thorough evaluation, the operator ii. Diamond round burs (No. 2 for anterior teeth and
will be able to accurately ascertain the pulp spaces No. 4 for posterior teeth) are commonly used to
present in the tooth under treatment. initiate entry in old restorations. Once the ‘drop’
• When the canal orifices are difficult to locate, rubber into the pulp chamber is attained, the overhanging
dam should not be placed until correct location has dentin is removed from the roof of the chamber
been confirmed. Isolating multiple teeth with rubber using tapered burs. Diamond points can also be
dam improves visibility and accessibility. used for axial wall extensions of the access cavity
• Endodontic entries are prepared through occlusal or preparation. But they need to be used with caution
lingual surface and never through proximal or as gouging of the pulpal floor and axial walls can

14 gingival surface. When proximal or gingival tooth

destruction occurs, affected areas should be
excavated and restored with either a temporary or
occur. Using burs and diamond points with safe
ended tips (non-cutting tips) have the advantage
of not damaging the pulpal floor and avoiding

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 Access Cavity Preparation 243

perforations. They can also be used to level off cusp access cavity preparation. Clinical and radiological
tips and incisal edges, which are used as reference examination is carried out to analyze the position, size,
points for working length determination. depth and shape of pulp chamber and also the number
iii. Transmetal burs will help in preparing access cavity and curvature of the radicular pulp. The dimensions
preparations through amalgams, all-metal cast of pulp chamber and canal orifices may be influenced
restorations, or metal copings of porcelain fused to by the amount of tertiary dentin deposition and also
metal crowns. The saw-tooth blade configuration presence of dystrophic calcifications/pulp stones, etc.
is efficient in reducing vibrations [preferred when The law of centrality (pulp chamber of every tooth is
entering a tooth with pulpitis (hot tooth)]. in the centre of tooth and at the level of the cemento-
iv. Extended-shank round burs, such as the Mueller bur enamel junction) should be used as a guide for initiating
and Munce Discovery burs, can be used in teeth access. The coronal pulp chamber is usually mesially
with receded pulp chamber and calcified orifices. placed, which should not be confused with law of centra-
The extra-long shank of these burs moves the head lity. The initial penetrating bur should be directed towards
of the handpiece away from the tooth, improving centre of circumference of cementoenamel junction.
the clinician’s visibility during access preparation. • The position of cementoenamel junction is identified
v. Gates-Glidden burs (X-Gates) can be used to enlarge by using periodontal probes, noting the complete
canal orifices of the access cavity starting with circumference.
smaller sizes and progressing to larger sizes. This • The complete visualization of anatomy of pulp
facilitates canal instrumentation during endodontic chamber is also guided by law of concentricity (the
procedures; X-Gates also facilitate removal of walls of pulp chamber are concentric to the external
internal flanges of dentin, if any, from the canal outline of the tooth at the level of cementoenamel
openings. junction). In case the operator finds deviated wall at
cementoenamel junction, the pulp chamber will also
d. Hand Instruments follow that deviation (e.g. if the tooth is narrow
The DG-16 and the JW-17 endodontic explorers are used buccolingually, the pulp chamber will also be narrow
to identify canal orifices and to determine canal buccolingually).
angulation. The endodontic spoon excavator can be • Angulation of tooth is also to be determined.
used to assist in removing coronal pulp and carious Conventional radiography or CBCT imaging are
dentin. helpful in ascertaining the angulation.
• The distance from the cusp tip to furcation area is to
e. Ultrasonic Instruments be measured (shank of bur for access preparation
Pulp stones, calcifications present in the pulp chamber should be selected short of this length to avoid
act as hindrances in accessing the canal orifices. mishaps at the furcation area).
Ultrasonically driven procedures remove bulky head
of traditional handpiece, facilitating better view of b. Preparation of Tooth
operating field. Ultrasonic tips can be used to trough Caries and defective restorations must be completely
and remove these obstructions. Fine ultrasonic tips are removed prior to preparation of access cavity enabling
smaller than conventional round burs, and their the operator to assess the remaining tooth structure for
abrasive coatings allow clinicians to remove dentin future restoration. The removal of existing restorations
conservatively. Ultrasonic procedures are utilized to may reveal hairline cracks on any axial wall, which may
refine and finish the access preparation. influence the prognosis of endodontic treatment and
require immediate attention.
Phases of Access Cavity Preparation The remaining caries and defective restorations must
The preparation of access cavity (initiating process of be removed for the following reasons:
cleaning pulp spaces) is to be carried out in phases; • To mechanically eradicate microorganisms from the
starting from pre-access analysis, preparation of tooth, inner side of the tooth.
removal of pulp chamber roof and coronal pulp, identifica- • If caries removal lead to perforation, the perforation
tion of canal orifices and preparing radicular portion. site is sealed from the inside, thus minimizing the
chances of saliva leaking into the prepared cavity
a. Pre-access Analysis
14
and contaminating it.
The anatomy of the tooth to be treated along with • To remove any discolored tooth structure, that may
surrounding tissues are evaluated before initiating ultimately lead to staining of the crown.

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 244 Essentials of Endodontics

Unsupported cusps should also be removed; or can The law of color change (the color of floor of pulp
be covered by orthodontic bands to prevent eventual chamber is always darker than the surrounding walls)
tooth fracture. In some cases, undercuts are filled with provides guidance to know whether the access outline
glass-ionomers or composites, which facilitate rubber is complete or not. The walls being lighter than floor,
dam placement as well as access cavity preparation. the junction of wall-floor is easily recognized (if
operator can see wall-floor junction, the access outline
c. Removal of Pulp Chamber Roof and Coronal Pulp is considered as ‘complete’).
The type and shape of burs are to be finalized keeping
in mind the pre-access factors (circumference of ii. Convenience form: Convenience form implies
cementoenamel junction, angulation of tooth and modifying the cavity design so as to facilitate easy
distance of cusp tip to furcation area). instrumentation during root canal procedures. It
The principles involved are by and large the same as provides:
Black’s principle for cavity preparation. The main • Unobstructed view of pulpal floor and the canal orifices:
principles are: During access cavity preparations, enough tooth
i. Outline form structure must be removed to enable a clear view of
ii. Convenience form the pulpal floor and possibly all the canal orifices.
iii. Cleaning the cavity The canal orifice may appear partially on the axial
wall giving a ‘mouse hole’ effect, if axial walls
i. Outline form: The outline form should be so shaped extension is incomplete.
as it must establish complete freedom for instrumenta-
• Unhindered access to the canal orifice: The root canal
tion during endodontic procedures. The external
instruments should be freely introduced into the
outline form is dictated by the internal anatomy of pulp.
orifice of each canal without interference from side
Because of this internal-external relationship, endodontic
walls.
preparations must be carried out in reverse manner,
from inside of the tooth to the outside. • Direct access to the apical foramen: Endodontic
To achieve optimal preparation, three factors of instruments can gain direct access to the canal in an
internal anatomy must be considered: unstrained position, even if the canal is severely
• Size of pulp chamber: The outline form is influenced curved.
by the size of pulp chamber. In young patients, • Outline extension to accommodate root canal filling
the preparations must be more extensive than in techniques: Rarely, the outline form may be appro-
older patients (pulp chamber is reduced three priately widened to carry out certain root canal filling
dimensionally in older patients). modalities.
• Shape of pulp chamber: The outline form should • Control over the instruments: The factors controlling
accurately reflect the shape of the pulp chamber. For the root canal instruments are: (i) The clinician's
example, teeth with three canals, reflect a triangular fingers on the handle of the instrument and (ii) the
shaped cavity outline; four canal anatomy will result walls of the canal at the tip of the instrument. Any
in a square, rectangular or rhomboid cavity outline. dentinal overhangs coming in between these two
• Configuration of root canals: To prepare each canal points would result in binding instrument in the
efficiently and without any interference, the cavity canal; subsequently leading to mishaps, such as root
walls are extended accordingly to allow for un- perforation, ledge formation, instrument breakage,
restricted instrument approach to the apical foramen. zipping or apical transportation.
The roof of pulp chamber is continually shaved off
following the sequence as: iii. Cleaning the cavity: The feature, cleaning of cavity
• Penetration phase: Round diamond point is used to is important, since loose debris invites bacterial growth
drill through the roof of the pulp chamber to make a and stain the tooth as well. After removing all the
way into the pulp chamber. hard and soft necrotic material, remnants of previous
• Enlargement phase: A long shank diamond point is restorations and debris are removed from the chamber
used to widen the pulp chamber and remove any with copious irrigation with a suitable irrigant. The
overhangs and obstructions to the canal orifices. chamber may finally be wiped out with cotton, and

14 • Finishing and flaring phase: A tapered non- end cutting

bur is used to smoothen the walls of the cavity and
make them slightly divergent towards the occlusal.
gently air dried to eliminate any remaining loose debris.
Air, if used, should not be directed towards the canal
orifices; it may cause emphysema.

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 Access Cavity Preparation 245

d. Identification of Canal Orifices Another important feature is to provide adequate

It is always difficult to know the number of root canals retention for the interim restorations. Availability of
prior to commencement of treatment. Radiographs do sufficient tooth structure facilitates adequate isolation
assess roots and canals, but may not be able to capture and also the feasibility of proper interim restoration.
all anatomical aberrations. The effective way is to In case, sufficient tooth structure is not available
analyse full view of pulp chamber floor and use (excessive loss of tooth structure, may be because of
different anatomic landmarks. caries or trauma), the placement of rubber dam is
As the floor-wall junction is clearly visible, the laws difficult; so as placing the interim restorative material.
of symmetry and the laws of orifice location are used The pre-endodontic build-up of the lost tooth
to identify the number and location of the orifices (law structure, commonly refer to as ‘Donut technique’,
of symmetry 1: Except for maxillary molars, the orifices implies building walls of the tooth around the access
of canals are equidistant from a line drawn in mesio- cavity, enabling retention of rubber dam and facilitating
distal direction through the centre of the pulp chamber; endodontic procedures (Fig. 14.25). The build-up
Law of symmetry 2: Except for the maxillary molars, procedure is performed with an adhesive composite,
the orifices of the canals lie on a line perpendicular to a which can last during the root canal treatment and
line drawn in a mesial-distal direction through the provide support for temporization. Earlier authors tried
centre of the pulp chamber flow; law of color change: several techniques, viz. placing clamp on gingiva,
The color of the pulp chamber floor is always darker clamping adjacent multiple teeth, copper bands, build-
than walls; Law of orifice location 1: The orifices of the up with amalgam and so on.
root canals are always located at the junction of the
walls and the floor; Law of orifice location 2: The orifices Procedure
of the root canals are located at the vertices of the floor- • After removing the caries and the soft tissues,
wall junction). astringent solution is applied to achieve hemostasis
The laws of orifice location 1 and 2 are very useful and to clean the area.
in identifying third/fourth root canal in premolars and • Gingival retraction cord is applied around the tooth
also to negotiate second mesiobuccal root canal (MB2) below the gingival margin (provide hemostasis and
in maxillary first molars. better visualization of any subgingival tooth
margins).
e. Preparation of Radicular Portion
• Place cotton pellets or appropriate sized rubber
After achieving unhindered access to the canal orifices, wheel over the pre-assumed access cavity.
the coronal end of the root canal is enlarged for better
• Around this area, flowable composite is applied
instrumentation during root canal treatment; a specific
initially, followed by curing composites in layers.
shape is to be developed to receive a root canal filling
Incremental curing provides better adaptation of
that is going to completely obturate the space previously
composites.
occupied by the pulp.
• A football-shaped diamond point is used to reduce
Except for calcified teeth, most orifices accommodate
the occlusal surface and contour the restoration.
the head of X-Gates, which on activation serve to open,
expand and flare the orifice. The lateral cutting with
X-Gates is used to intentionally relocate the coronal-most
aspect of the canal away from the furcal danger (cross-
sections through coronal one-third of furcated roots reveal
that canals are not exactly centred within the root;
generally displaced towards the furcal side concavities).
The preflared orifices produce smooth flowing funnel to
facilitate subsequent instrumentation. Ni-Ti orifice shapers
(different sizes available) are preferred to flare the canal
orifices. Many authors do not favour use of gates-glidden
burs, as they believe, lead to excessive dentin damage.

PRE-ENDODONTIC BUILD-UP TECHNIQUE

One of the requisite of access cavity preparation is to
provide ‘field of operation’ completely dry and isolated. Fig. 14.25 Pre-endodontic build-up
14

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 246 Essentials of Endodontics

• The build-up should mimic the natural anatomical

structure, which can be used as guide for access
cavity and further endodontic procedures.
The techniques of pre-access endodontic build-up
has been modified by various authors.
After negotiating canal orifices and removing caries/
old restorations, etc. a canal projector cone is inserted
into each canal. After stabilizing the cones, adhesive
composite is built around the cones. Once, completely
set and finished, the cones are removed to facilitate
routine endodontic procedure.
A few authors have placed gutta-percha points and
even ‘posts’ into the canal orifices, followed by building a
the lost walls in routine with adhesive composites. The
rubber dam is sealed with Oraseal, if any leakage of
saliva is suspected after build-up procedure. The
technique is effective in maintaining dry field during
the endodontic procedures, improving visualization
and instrumentation as well.

CONSERVATIVE ACCESS CAVITY PREPARATIONS

Conservative access cavity preparation, also known as
‘Minimal invasive endodontics’ or even ‘Micro-
endodontics’, implies preparing smaller access cavities
and using smaller tapered files to conserve more of
dentin around pulp spaces (Fig. 14.26a and b).
The rationale of conservative endodontic preparation
is to preserve pericervical dentin [Dentin 4.0 mm above
and 6.0 mm below the cementoenamel junction of all teeth is
pericervical dentin (PCD)]. It is not all about making
b
'small' preparations, but about designing cavity in such
a way so as to preserve maximum dentin and also Fig. 14.26a and b Conservative access cavity
fulfilling the treatment objectives. Pericervical dentin
is considered as crucial for tooth strength and for long- Clarke and Khademi, credited with the idea of
lasting restorations. conservative cavity preparation, encourages the use of
It has been established that greater the amount of endoguide burs (instead of round burs and gates-
dentin conserved, the greater the increase in strength. glidden burs) for access and orifice enlargement along
The conservative designed molars have been observed with orifice openers. They prefer use of V-taper rotary
to be 2.5 times stronger than traditionally designed Ni-Ti variable taper files (diameter less than 1.0 mm as
molars. midcanal shaft size).
Conservative cavity preparation involves reducing Maintaining pericervical dentin is considered a key
the excessive widening of pulp chamber, eliminating factor in reducing fractures in endodontically treated
the convenience form and also using instruments of teeth. Smaller tapers are also preferred in calcified and
smaller flute diameter, especially at the coronal ends severely curved canals. However, it is opined that the
of the root canals. It disregards the traditional require- conservative preparations should not take precedence
ment of a straight line access and complete unroofing over traditional preparations, which are necessary to
of the pulp chamber and emphasize the importance of locate, negotiate and prepare the root canals.
preserving crucial pericervical dentin as far as possible.
Since no restorative material or technique can overcome Clinical Tips

14 the lost dentin, the steps should be directed to conserve

dentin, especially in key areas of tooth, so as to buttress
the endodontically treated teeth.
The operator should have the knowledge of different
variations in canal anatomy and also the possibility of
extracanals to achieve successful root canal treatment.

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 Access Cavity Preparation 247

The important clinical tips are:

• Two or more radiographs taken at 30° mesial/distal
angulation must be thoroughly evaluated before
initiating endodontic procedures (SLOB: same
lingual, opposite buccal rule be applied to visualize
location of canals).
• Sudden disappearance or narrowing of radiolucency
of root canal in-between the root indicates bifurcation
of root canal (fast-break phenomenon of Slowey).
• If the outline of root has unusual contour or not very a b c
clear, one should suspect extracanal.
• Proper ‘reading’ the radiograph may reveal lateral Fig. 14.27 (a) Creating nick using inverted cone bur;
canals; a knob-like eversion of apex reveal curved (b) Angulation of round bur during access cavity
apex towards/away from X-ray beam. preparation; (c) Change in angulation of fissure bur during
• Canal/root curvatures should be evaluated on access cavity preparation
‘angled radiographs’; palatal root of maxillary molars
usually have sharp apical curvatures towards the
buccal.
• Canal located in the centre of pulpal floor indicate
presence of one canal only.
• When two canals join to form one canal, lingual/
palatal canal has direct access to apex.
• When the first file inserted into distal canal of
mandibular molar shows buccal/lingual direction;
possibility of second distal canal.
• Pulp floor should be analysed with the possible
magnification. Fiberoptic illumination can reveal
orifices location, calcifications, fracture lines, etc.

CAVITY DESIGNS FOR INDIVIDUAL TEETH a b c

Maxillary Anterior Teeth Fig. 14.28 (a) Improper access cavity (pulp remnants left
Maxillary anterior teeth are mostly single rooted with in coronal half); (b) Proper access cavity (mesiodistal view);
1-1 canal configuration (rarely two roots and extra- (c) Proper access cavity (labiolingual view)
canals present).
extended according to need. Pulp tissue remnants
Steps of Access Cavity Preparation should not be left in the pulp chamber, which may
(Applicable for all Anterior Teeth) get infected/re-infected, subsequently leading to
• The first step is to give a “nick” just below the failure of the root canal therapy (Fig. 14.28a). Such
cingulum in the center of the lingual surface with residual pulp remnants may also discolor the
the help of an inverted cone bur, keeping the bur remaining tooth structure.
perpendicular to the tooth surface. The nick prevents • The access is enlarged both labiolingually and
slipping of the bur into the gingival sulcus mesiodistally. In the labiolingual direction, labial and
(Fig. 14.27a). lingual triangles should be removed. In the mesio-
• Through this ‘nick’, penetrate into dentin with the distal direction, pulp horns should be uncovered
help of appropriate round bur, keeping it perpendi- (Fig. 14.28b and c).
cular to the tooth surface (Fig. 14.27b). • Small round bur can be used to eliminate remnants
• Once dentin is reached, the bur is held parallel to of caries and attached debris, if any.
the long-axis of the tooth until the pulp chamber is • The root of maxillary central incisor is inclined
reached (Fig. 14.27c).
• Now using tapering fissure bur, the walls of the pulp
chamber is removed from inside to outside and
5–10° palatally. Therefore, the bur should be angled
accordingly, to be parallel to the long-axis of the
tooth. This angle is known as ‘access angle’. The
14

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 248 Essentials of Endodontics

a b c

Fig. 14.29a to c Access cavities of maxillary anterior teeth

palatal inclination of root of lateral incisor is 25–30°

and that of canines is 17–20°. Usually, these teeth
are distally tilted also. Care should be taken to follow
the access angle accordingly.
• The extensions of pulp horns should be thoroughly
evaluated and preferably included in cavity design.
• The shape of access cavities of maxillary anterior
teeth is depicted in Fig. 14.29a to c.
It is important to note that in all incisors, a better
straight line access can be achieved through an incisal
access; the lingual approach is preferred to maintain
the labial surface intact for esthetic reasons.
a b c
In case the tooth is to be restored with full veneer
crown, the endodontic access may be achieved through
incisal surface.
Fig. 14.30a to c Mishaps during access cavity preparation
Errors in Access Cavity Preparation of (anterior teeth)
Maxillary Anterior Teeth
• Gouging of labial wall-caused by failure to recognize Maxillary First Premolar
the linguoaxial inclination of tooth (most important Maxillary premolars account for 15–20% of the total root
is maxillary lateral incisors). canal treated teeth. The maxillary first premolar is pre-
• Gouging of distal wall-caused by failure to recognize dominantly two rooted teeth with two canals (variety
mesioaxial inclination of tooth. of canal aberrations have been reported). The operator
• Pear-shaped preparation of apical area caused by should be familiar with the possible variations of these
failure to achieve proper convenience form. teeth before initiating root canal treatment.
• Discoloration of crown caused by failure to remove Steps of Access Cavity Preparation
pulp debris. The access cavity is too far gingivally
• The access cavity is prepared using tapered fissure
with minimum incisal extension.
bur keeping parallel to the long-axis of the tooth,
• Ledge formation at apical-labial/apical-distal curve starting from center of the fossa and moving to buccal
caused by failure to achieve the proper convenience and palatal sides. The oval shape is achieved.
form.
14 • Mishaps during access cavity preparations (anterior
teeth) are depicted in Fig. 14.30a to c.
• An appropriate round bur is used to open into the
pulp chamber. The tactile sense will feel ‘dropping
the bur’ when the pulp chamber is reached. In chronic

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 Access Cavity Preparation 249

cases and also where the pulp is calcified, such a ‘drop’ Maxillary Second Premolar
is not felt. (Minimum of 2.0 mm of pulp is necessary Maxillary premolars account for 15–20% of the total root
to feed the ‘drop’). The bur can be penetrated deep canal treated teeth. The maxillary second premolars are
clearing the pulp chamber. Care must be exercised predominantly one rooted teeth with 1 or 2 canals (canal
not to injure the furcation area (Fig. 14.31a to c). aberrations are quite common). The operator should
• After penetrating the pulp chamber, the orifices can keep in mind the anatomical variations of these teeth
be located using fine instruments and follow the laws before root canal treatment.
of orifice location as described earlier.
• The buccal canal lies beneath the buccal cusp and Steps of Access Cavity Preparation
the palatal canal lies beneath the palatal cusp. • The access cavity preparation is same as for maxillary
• The lumen of the palatal canal is larger than that of first premolar.
buccal canal. The buccal canal is generally more • Usually one canal is present in the center; however,
difficult to negotiate. if the canal is not negotiated at the center, there is
• One should explore the possibility of third canal, possibility of a second root canal.
which is usually in mesiobuccal direction. • The two canals, if present, are palatal and buccal.
• The shape of the access cavity is depicted in • Very rarely third canal can also be present.
Fig. 14.32. • The shape of the access cavity is depicted in Fig. 14.33.
Errors in Access Cavity Preparation of
Maxillary Premolars
• Under-extended preparation (the white color of roof
of chamber is a clue to shallow cavity).
• Over-extended preparation (undermining of enamel
walls).
• Failure to observe the distal-axial inclination of tooth
may lead to perforation (maxillary first premolar is
the most susceptible tooth to be perforated).
• Failure to explore the third canal in first premolar.
• Failure to explore second canal in second premolar.

Maxillary First Molar

a b c
The maxillary first molar has three separate roots: two
Fig. 14.31 Access cavity preparation in maxillary premolars buccal and one palatal with one canal in each root. The
(a) Initiation of access cavity preparation; (b) Removal of palatal canal is wider than either of the buccal canals.
root with tapered fissure bur; (c) Completed access cavity The palatal orifice is largest and is easily accessible. It

Fig. 14.32 Maxillary first premolar (diagrammatic) Fig. 14.33 Maxillary second premolar (diagrammatic)
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 250 Essentials of Endodontics

Fig. 14.34 Shape of access cavity preparation: (a) Maxillary first molar (diagrammatic: three canals); (b) Maxillary first
molar (diagrammatic: four canals)

lies near the central pit, mesial to oblique ridge. Maxillary Second Molar
Mesiobuccal orifice lies under mesiobuccal cusp and is The maxillary second molar is mostly three rooted with
longer buccopalatally; may have a depression at palatal three root canals; however, two rooted and single rooted
end in which the orifice of a fourth canal may be present second molar with corresponding canal anatomy is also
(MB2). Distobuccal orifice is located slightly distal and common. Aberrations in pulp spaces are quite prevalent.
palatal to the mesiobuccal orifice.
Steps of Access Cavity Preparation
Steps of Access Cavity Preparation • The radiograph should thoroughly be evaluated
• Access cavity preparation should be initiated in the before starting the access cavity preparation. Semi-
mesial fossa using an appropriate size of round bur parallel technique can be followed during getting
followed by fissure bur. radiographs if molar prominence interferes in the
• The fissure bur is extended towards the mesiopalatal proper viewing of the root canals (a piece of cotton
is placed between the tooth and the film; radiations
cusp as the orifice of palatal canal is present beneath
are directed bisecting the two).
the mesiopalatal cusp.
• The access cavity is prepared in the same manner as
• The orifice of mesiobuccal canal is located beneath for the first molar. The access is achieved from the
the mesiobuccal cusp but the distobuccal canal orifice mesial side only.
does not relate to its cusp. It is usually located by • The floor of the access cavity is more dome-shaped.
means of its relation to the mesiobuccal orifice and • The mesiobuccal canal and root are not as long as
is found approximately 2.0 to 3.0 mm to the distal those of the first molar.
and slightly to the palatal aspect of the mesiobuccal • The mesiobuccal canal if present, pose difficulties in
orifice. negotiation, because of distally placed tooth.
• The orifice of palatal canal is located, followed by • The shape of the access cavity is depicted in Fig. 14.35.
other two canals using fine instruments.
• The access cavity is given a quadrilateral shape.
• The mesiobuccal root shows a second canal called
MB2, which is found 1.0– 2.0 mm palatal to the main
mesiobuccal canal.
• Very rarely the palatal and the distobuccal roots can
have extra root canals.
• The access cavity is kept mesial to the oblique ridge.
There is no need to sacrifice the oblique ridge in
preparing the access cavity as all orifices of canals
lie in the mesial three-fifths of the crown.
14 • The shape of the access cavity is depicted in
Fig. 14.34a and b. Fig. 14.35 Maxillary second molar (diagrammatic)

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 Access Cavity Preparation 251

Maxillary Third Molar (Fig. 14.36a). Initially, only enamel is penetrated (as
Maxillary third molars are commonly three rooted; in maxillary incisors).
number of roots may range from one to five. The number • Through the nick, the access cavity is deepened up
of root canals also vary accordingly. Presence of MB2 to dentin using round bur, keeping bur perpendi-
in mesiobuccal root is also prevalent. cular to the tooth surface (Fig. 14.36b).
• With appropriate fissure bur, directing parallel to the
Steps of Access Cavity Preparation tooth surface, the cavity is extended mesiodistally
• Since, the tooth is placed in the most posterior to include the pulp chamber. The enamel and dentin
location with minimum opening space, certain are beveled towards the incisal surface (Fig. 14.36c).
guidelines should be followed, such as: • Final access cavity shape is ovoid and funnel-shaped,
– Use of short head handpiece which is wider labiolingually (access cavity must be
– Use of short files; short shank drills wider labiolingually and inciso-gingivally to locate
– Mouth prop to facilitate mouth opening. extracanals, if any).
• Radiograph of these teeth needs extra cautions. Place- • The preparation is similar for lateral incisors and
ment of film may lead to gag-reflex, which get worse canines.
while placing rubber dam. It can be controlled by: • The possibility of extracanals should be explored
– Semi-parallel radiographic technique is preferred thoroughly.
– Patient is asked to breathe through nose only; • The shape of access cavity is depicted in Fig. 14.37a to c.
tongue is to be relaxed
– Minimize patient apprehension by suitable drugs
– In extreme cases, tongue and palate can be
anesthetized.
• Opening and negotiation of canals is same as for
maxillary second molars.
• The association of roots of maxillary third molar with
maxillary sinus is to be evaluated thoroughly and
managed accordingly.
Errors in Access Cavity Preparation in
Maxillary Molar Teeth
• Under-extended preparation (entire roof of pulp a b c
chamber remains).
• Over-extended preparation (undermining enamel Fig. 14.36 Access cavity preparation in mandibular anterior
walls). teeth: (a) Creating a ‘nick’ using inverted cone bur;
• Furcation perforation, especially using a long shank (b) Extending access cavity using fissure bur; (c) Completed
bur (failure to realize the distance from cusp tip to access cavity
furcation area).
• Improper outline from exposing only the palatal canal.
Mandibular Anterior Teeth
Mandibular anterior teeth are usually single rooted with
slight distobuccal curvature. One root canal is prevalent;
however, two or more canals may also be present.
Wilson and Henry (1965) have cautioned that during
treatment of mandibular incisors, due to anatomical
inaccessibility, organic debris may remain in the lingual
a b c
aspect of the canal as the instrument always passes
along the labial aspect of canal.
Steps of Access Cavity Preparation
• A small ‘nick’ is given just above the cingulum using
inverted cone bur perpendicular to the tooth surface
Fig. 14.37a to c Access cavities in mandibular anterior
teeth (diagrammatic)
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Errors in Access Cavity Preparation of Mandibular Second Premolar

Mandibular Anterior Teeth Mandibular second premolars are usually single rooted;
• Gouging of labial wall-caused by failure to recognize roots may be curved distobuccally. The crown is tilted
the linguoaxial inclination of the tooth. slightly to lingual side (much less than first premolar)
• Gouging of distal wall-caused by failure to recognize and also distally. Extraroot canals are common and
the mesioaxial inclination of the tooth. should be explored thoroughly.
• Failure to explore the extracanal (inadequate inciso-
gingival extension of access cavity). Steps of Access Cavity Preparation
• Discoloration of crown caused by failure to remove • Access cavity is prepared in the same manner as the
pulp remnants (the access cavity may be too far first premolar. (Usually has one root and one well-
gingivally with minimum incisal extension). centered canal; but may have bifurcated canals.)
• Ledge formation caused by complete loss of control • Access is made ovoid, wider in the buccolingual
of instrument, especially if access cavity prepared dimensions (Fig. 14.39).
through proximal surfaces.
Errors in Access Cavity Preparation in
Mandibular First Premolar Mandibular Premolars
Mandibular first premolar is usually single rooted; • Perforation at distogingival area (failure to recognize
more than one root may be present. The crown is the distal tilt of premolar)
lingually tilted and distally inclined. Aberrations in • Incomplete preparation may lead to loss of instru-
canal anatomy are quite common; prevalence of ment control.
bifurcated canals may be up to 60%.
Mandibular First Molar
Steps of Access Cavity Preparation
Mandibular first molar generally is two rooted with
• The preparation is started in the middle of the central three distinct root canals. The pulp chamber is mesially
groove using round/fissure bur. placed, so access is directed within from central pit to
• The bur is extended more buccally and less lingually. mesial pit. Extra root canals, especially in distal root
The occlusal opening is widened buccolingually to should be explored thoroughly (40% may have two root
twice the width of the bur to allow room for exploration. canals; distobuccal and distolingual). A few molars may
• The canal is located with the help of an explorer. have extradistal root with separate canal.
Working from inside to outside, the roof of the pulp
chamber is completely removed with appropriate Steps of Access Cavity Preparation
fissure burs. • General outline of the access cavity is trapezoidal.
• Final preparation is ovoid and tapered towards The buccal and lingual sides are of approximately
cementoenamel junction, providing a straight line the same configuration and taper towards each other
access to the canal(s) (Fig. 14.38). distally.

14 Fig. 14.38 Mandibular first premolar (diagrammatic) Fig. 14.39 Mandibular second premolar (diagrammatic)

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 Access Cavity Preparation 253

• The access cavity is confined to mesial half of the

crown.
• The access cavity preparation is started just mesial
to the central pit. Since, the tooth is lingually and
mesially inclined, the bur should mimic these
angulations.
• The orifice of the distal canal lies beneath the central
pit. It is generally large and slightly elliptical.
• The mesiolingual canal lies beneath the mesial pit.
The mesiobuccal canal lies beneath the mesiobuccal
cusp. The orifices are often connected by a groove
which helps to locate both canals (5% mandibular
molars have three mesial canals; middle mesial canal
is usually located between mesiobuccal and mesio- Fig. 14.41 Mandibular second molar
lingual canal).
• An appropriate bur is used to remove the roof of Mandibular Third Molar
pulp chamber guiding the bur from inside to outside. Mandibular third molars usually have two roots and
• A wider access cavity to locate extracanals is consi- two root canals. The tooth is mostly mesially inclined,
dered better than ignoring these canals for the sake which facilitate access cavity preparation. Isolation is
of a ‘conservative’ preparation, which may lead to usually difficult in third molars.
failure.
• The shape of the access cavity is depicted in Fig. 14.40. Steps of Access Cavity Preparation
• The access cavity preparation for mandibular third
Mandibular Second Molar molar is almost same as for mandibular first and
Mandibular second molar is similar to first molar and second molars, with the variation as the anatomic
is more compact; mostly two rooted with three canals structures may dictate.
(two mesial and one distal). Two roots and two canals • Roots lie close to mandibular canal; operator should
are also prevalent. The mesial canals are usually close be careful during endodontic procedures. Following
to each other and the incidence of second canal in distal features are important:
root is rare. The volume of the pulp chamber and canal – Avoid mechanical trauma (over-instrumentation)
entrances are smaller than in first molars. – Use of side vented needles and less concentration
of irrigant solution.
Steps of Access Cavity Preparation – Avoid pressure irrigation (extrusion of toxic
• Access cavity is prepared in the same way as in the chemicals cause damage and even delay healing).
case of a first molar. – Avoid using thermal techniques, such as thermo-
• C-shape canal configuration is common. plasticized gutta-percha for obturation.
• The shape of the access cavity is depicted in Fig. 14.41. • In case the access is unmanageable, autotrans-
plantation can be considered (third molars are consi-
dered reliable to replace missing first/second molars).

Errors in Access Cavity Preparation of

Mandibular Molar Teeth
• Overextended preparation (undermining enamel
walls).
• Furcation perforation by using long shank bur
(failing to realize that the narrow pulp chamber had
passed).
• Perforation at mesial cervical area (failure to orient

Fig. 14.40 Mandibular first molar

bur in severely tipped molars).
• Improper outline form exposing only mesiobuccal
canal.
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 254 Essentials of Endodontics

c. Rotated Teeth
Rotated teeth have an altered crown-root relationship
posing difficulties like difficulty in canal location and
débridement. Access cavity preparation may also lead
to perforation. Similar problems can occur in the case
of crowded teeth; buccal access preparation is preferred
in such cases.

d. Access Cavity in Restored Teeth

Preparation of access cavities through crowns or
extensive restorations is very challenging because of
the altered shape of the clinical crown (crowns usually
a b mask the orientation of tooth). If the canals are not
identified by cutting through the crown, it is necessary
Fig. 14.42 Mishaps during access cavity preparation
to remove the crown to avoid further damage.
(mandibular molars). (a) Furcation perforation; (b) Lateral Removing crown will reduce the likelihood of removing
(cervical) perforation sound dentin unnecessary and also minimizes chances
of perforation.
• Mishaps during access cavity preparations (mandibular
molars) are depicted in Fig. 14.42a and b. BIBLIOGRAPHY
1. Ahmed HM. Management of third molar teeth from an
ACCESS CAVITY PREPARATION IN DIFFICULT CASES endodontic perspective. Eur. J. Gen. Dent.: 2012; 1:48–60.
a. Teeth with Limited Mouth Opening 2. Beaudry RJ. Prevention of rubber dam hypersensitivity. J.
Endod.: 1984; 10:544–545.
Limited mouth openings or unfavourable position of
tooth in the arch result in difficulty in aligning the bur 3. Buhrley IJ, Barrows MJ, BeGole EA and Wenckus CS. Effect
of magnification on locating the MB-2 canal in maxillary
and the handpiece along the long-axis of the tooth.
molars. J. Endod.: 2002; 28:324–327.
Location of canals and their preparation always pose
4. Calberson, FI., De Moor, RJ and Deroose, CA: The radix
problems. Use of mouth prop and pediatric handpiece
entomolaris and paramolaris: clinical approach in
can be helpful to some extent. The shank of burs can be endodontics. J. Endod : 2007; 33, 58–63.
shortened by 3.0–4.0 mm; or the cusp tips are reduced
5. Carrotte P. Endodontics: Part 6 Rubber dam and access
so as to improve the visibility and accessibility prior to
cavities. Br. Dent. J.: 2004; 197:527–534.
negotiating and preparing the canals.
6. Clark D and Khademi J. Modern molar endodontic and
b. Teeth with Calcified Canals directed dentin conservation. Dent. Clin. N. Am.: 2010;
54:249–273.
Pulp calcifications pose a problem in locating canals.
7. Dias de Andrade E, Ranali J, Volpato MC, Motta Maia de
Localized deposition of tertiary dentin as a result of Oliveira M. Allergic reaction after rubber dam placement. J.
caries or leakage, will reduce the volume of pulp Endod.: 2000; 26:182–183.
chamber. The pulp chamber floor becomes flatter with 8. Greene RR, Sikora FA and House JR. Rubber dam application
narrow canal entrances. Careful use of magnification, to crownless and cone-shaped teeth. J. Endod.: 1984; 10:
and tests like ‘champagne bubble’ test, can help the 82–84.
clinician to locate these canals. Long shank burs or 9. Hauman CH, Chandler NP and Tong DC. Endodontic
ultrasonics should be used to remove tertiary dentin. implications of the maxillary sinus: A review. Int. Endod.
Pulp stones and calcifications are also removed with J.:2002; 35:127–141.
long shank excavation and ultrasonic tips. Once canal 10. Hilu RE and Zmener O. Endodontic management of two
entrance is identified, a small file (K1 size 06 or K2 size mandibular third molar with c-shaped root canals: A case
08) should be used in slow progressive motion to nego- report. Endod. Pract.: 2007; 10:21–24.
tiate the canal. Rigid C-Pilot files having cutting tips 11. Hou GL and Tsai CC. Fusion of maxillary third and super-
are considered ideal to negotiate sclerosed canals (these numerary fourth molars: Case report. Aust. Dent. J.: 1989;

14 files are less likely to distort during canal negotiations).

In all such cases, periodic radiographs should be taken
to confirm the orientation of file in the canal.
34:219–222.
12. Jafarzadeh H and Abbott PV. Dilaceration: Review of an
endodontic challenge. J. Endod.: 2007; 33:1025–1030.

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13. Kilic C, Kamburoglu K, Yuksel SP and Ozen T. An assessment 20. Ricucci D, Siqueira JF. Fate of the tissue in lateral canals and
of the relationship between the maxillary sinus floor and the apical ramifications in response to pathologic conditions and
maxillary posterior teeth root tips using dental cone-beam treatment procedures. J. Endod.: 2010; 36:1–15.
computerized tomography. Eur. J. Dent.: 2010; 4:462–467. 21. Schilder H. Cleaning and shaping the root canal. Dent. Clin.
14. Krasner P and Rankow HJ. Anatomy of the pulp chamber North Am.: 1974; 18:269–296.
floor. J. Endod.: 2004; 30:5–16. 22. Turell IL and Zmener O. Endodontic therapy in a fused
mandibular molar. J. Endod.: 1999; 25:208–209.
15. Moreinis SA. Avoiding perforation during endodontic access.
J. Am. Dent. Assoc.:1979; 98:707–712. 23. Weine FS and Buchanan LS. Controversies in clinical
endodontics: Part I- the significance and filling of lateral
16. Patel S and Rhodes S. A practical guide to endodontic access canals. Compend. Contin. Educ. Dent.:1996; 17:1028–1032.
cavity preparation in molar teeth. Br. Dent. J.: 2007; 203:
133–140. 24. Weine FS. The enigma of the lateral canal. Dent. Clin. North
Am.:1984; 28:833–852.
17. Patterson CJ. Polydam-polythene sheet, a practical alternative
25. Weller RN and Hartwell G. The impact of improved access
to rubber dam for patients allergic to rubber compounds. Int.
and searching techniques on detection of the mesiolingual
Endod. J.: 1989; 22:252–253. canal in maxillary molars. J. Endod.: 1989; 15:82–83.
18. Rankow HJ and Krasner P. The access box: An Ah-Ha 26. Yoshioka T, Kobayshi C and Suda H. Detection rate of root canal
phenomenon. J. Endod.: 1995; 21:212–214. entrances with a microscope. J. Endod.: 2002; 28:452–453.
19. Riccuci D. Apical limit of root canal instrumentation and 27. Zeylabi A, Shirani F, Heidari F and Farhad AR. Endodontic
obturation, part 1: literature review. Int. Endod. J.: 1998; management of a fused mandibular third molar and
31:384–393. distomolar: A case report. Aust. Endod. J.: 2010; 36:29–31.

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Chapter
15
Working Length
and Working Width

The root canal preparation is carried out with the aim It is established that the tissue beyond the cemento-
to preserve the biological integrity of the periapical dentinal junction is not pulpal. The apical constriction
tissues so as to provide conducive environment for is the junction where the pulpal tissue terminates and
healing. The nature has provided an apical constriction the periodontal tissue begins.
area inside the root canal, which acts as a natural barrier. The distance from the radiographic apex to the apical
It is imperative that the operator should restrict intra- constriction generally varies considerably from root to
canal treatment procedures to the apical constriction root. Histologically, cementodentinal junction being
or cementodentinal junction. Instrumentation beyond highly irregular, did not coincide with the apical
this junction can cause inflammation in the periapical constriction. It may be up to 3.0 mm higher on one wall
tissues, subsequently failure of the treatment. The than the opposite wall. Thus, it is difficult to accept any
length of the canal from the coronal access to the apical distances from the radiographic apex as an accurate
constriction is the ‘working length’. indicator for the termination of the endodontic
Before proceeding to know the modalities of working instrumentation and obturation.
length measurement, it is mandatory to understand the Very rarely the root canal ends at the radiographic
anatomy of root apex. apex, it frequently ends at a distance short of the apex.
The apical foramen does not always lie at the exact
ANATOMY OF THE ROOT APEX apex of the tooth. Usually, it exits laterally short of the
radiographic apex.
The root apex visualizes the junction where dentin ends
and the cementum/periodontal tissue begins (Fig. 15.1).
The cementum portion is usually in the form of an
inverted cone with its shortest or narrowest diameter
near the cementodentinal junction and base at the apical
foramen. The configuration of cementodentinal junction
may vary in different teeth. Cementum may be at edge
to edge with dentin at the apex or may extend for a
considerable distance into the root canal, lining the
dentin. Such an extension of cementum onto dentin is
usually unorganized and irregular. This is more
prevalent in periodontally involved teeth.
The apical pulp tissue differs structurally from the
coronal pulp tissue. The coronal pulp tissue consists
mainly of cellular connective tissue and fewer collagen
fibers; whereas, the apical pulp tissue is more fibrous
and contains fewer cells.
The fibrous tissue of the apical pulp is identical to
that of the periodontal ligament. This fibrous tissue acts Fig. 15.1 Root end anatomy diagrammatic: (a) Cementum,
as a barrier against the apical progression of pulp (b) apical formation, (c) cementodentinal junction,
inflammation. (d) minor constriction, (e) root canal, (f) major opening

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 Working Length and Working Width 257

The root canals usually deviate from the long-axis Apical termination of Root Canal Preparation and
of their roots and the openings may be 0.2 to 3.8 mm Obturation
short of apex. When the foramen ends on the buccal or The exact point/area up to which level the root canal
the lingual aspect, it is not possible to recognize it radio- is prepared and subsequently filled, remains debatable.
graphically. Various authors are of different opinion; however,
In such situations, the apex locators can be of great following four views are discussed.
help in accurately locating the apex as an adjunct to a. Short of the radiographic apex
conventional radiography. This is because they actually b. At the radiographic apex
locate the apical constriction or the vital periodontal c. Beyond the radiographic apex
ligament tissue. d. At the cementodentinal junction
It is demonstrated that the apical foramen deviates
from the tip in at least 2/3 rd of the teeth. Furthermore, a. Short of the Radiographic Apex
the deviation occurs towards the buccal or lingual This working length can be calculated by generally
aspects twice as often as it does towards the mesial or identifying the radiographic apex and then subtracting
distal aspect. a specific measurement from this length. Earlier, the
The following features govern the configuration of specific measurement was considered to be 0.5 mm; but
later, 1.0 mm was considered adequate, since cemento-
the foramen:
dentinal junction was usually more than 0.5 mm from
• As age increases, the center of the foramen deviates the root apex.
more and more from the vertex of apical center because
of increase in thickness of the apical cementum. Disadvantages
• When the canal exits more than 1.0 mm short of the
• The diameter of the foramen increases with age
radiographic apex, this length could result in tear-
because of apposition of new layers of cementum.
drop apical preparations and, subsequently lead to
The average diameter is somewhat larger bucco-
overfilling.
lingually than mesiodistally.
• If the working length is kept 1.0 mm short of the
• The minor diameter of the root canal is found usually apex, a large number of lateral and accessory canals
in the dentin just before the canal penetrates the may remain unsealed.
cementum. From this point onwards, the canal
gradually increases in size to form a funnel shape. b. At the Radiographic Apex
This funnel shape is accentuated in the older teeth It is believed that it might be difficult to determine the
because of widening of the foramen and narrowing location of the cementodentinal junction clinically and
of the canal. that the radiographic apex is the only reproducible site
• The average thickness of the apical cementum is in this area. It is also demonstrated that calculating
0.5 mm in the younger age group and 0.67 mm in working length to the radiographic apex and using
the older age group. larger files a bit shorter in the body of the canal; the
preparation achieved is ideal.
• Since the diameter of the foramen is uneven and
because of its shape, this portion cannot be sealed Disadvantages
hermetically unless it is overfilled with cement. • The position of radiographic apex may not be exactly
reproducible because of:
The components of root apex – Angulation of the tooth
• Apical center – Position of the film
• Center of the foramen – Holding agent for the film
• Distance between vertex and apical foramen – Length of the X-ray cone and the technique used
– Anatomic structures adjacent to the tooth.
• Diameter of the foramen (major diameter of the
canal) • When the canals exit short of the radiographic apex,
filling to this point could result in ‘tear-drop’ shape
• Diameter of the foramen perpendicular to the axis preparations, which are very difficult to seal.
of the canal
• Diameter of the canal at cementodentinal junction
(minor diameter of the canal).
• A root canal filling that generally extends to the apex
radiographically is extruding in actuality. This causes
impingement onto the vital tissues.
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 258 Essentials of Endodontics

• Complete regeneration of cementum and bone does • Minor errors (0.5–1.0 mm) on either side, i.e. long or
not usually occur around teeth with overfilled root short will not be much harmful.
canals. • Allows the development of an apical dentinal matrix
• The epithelium may grow around the filling material. against which filling material can be easily con-
The possibility of radicular cyst formation is densed. It helps to retain the filling material within
enhanced. Even if repair occurs, a fibrous encapsula- the canal.
tion usually remains around the excess filling material. • Prevents obturating material and the sealer from
escaping through the foramen.
c. Beyond the Radiographic Apex
• Anatomically and histologically, the constriction area
A few operators prefer to fill the canal beyond the is ideal.
radiographic apex. They are of the view that the puff
or button formed at the apex is designed to compensate Disadvantages
for the shrinkage of the gutta-percha and hence pulls • Difficult to recognize the constriction area
the filling closely down the apex. However, these
• Time consuming
reasonings are not authentic.
• May need costly gadgets.
Overfilled canals may lead to more incidence of dis-
comfort. In case of periapical radiolucencies, the preparation
may need to be terminated all the more coronally. If a
The inflammatory response persists regardless of the
definite periapical radiolucency is seen with an
type of filling material. No foreign material implanted
indication of root resorption, then reduce working length
in living tissue is inert. If the material is toxic, the
by further 0.5 mm. If root resorption is extensive, then
surrounding tissue gets necrotic. If the material is non-
working length may need to be reduced by even 2.0 mm.
toxic, three types of responses can occur:
It is established that the most clinically relevant
i. If the material is dissolved, the area is replaced by
working landmark is the apical constriction, regardless
surrounding tissue.
of whether it is in dentin or cementum. The constriction
ii. If the material is biologically inactive, a fibrous is the narrowest point of the canal and therefore
encapsulation of varying thickness forms. minimum of blood supply. The cleaning and shaping
iii. If the material is biologically active, an interfacial up to the apical constriction completely eliminates
bond forms. pathogenic canal contents and provides conducive
Many clinical studies have shown that with this environment for healing.
technique, clinical success is poor and chances of failure
are increased. ASSESSING APICAL CONSTRICTION AREA
d. At the Cementodentinal Junction Various methods and techniques are being employed
It has been established that narrowest diameter of the to exactly assess the apical constriction area. The
canal was not at its site of exit, but in the dentin just routinely used methods are:
before the cementum. This site is referred as the ‘minor 1. Tactile Method
diameter’, also known as ‘apical constriction’. Beyond
that the canal widens as it joins the periapical areas. This method utilizes tactile sense of the operator, i.e.
This is known as ‘major diameter’. The major diameter is ability of the fingers to perceive the presence of an apical
almost twice as that of the minor diameter. The distance constriction. After access cavity preparation and
between the two is approximately 0.5 mm for 18–25 years establishing patency of the canals, an appropriate file
of age group and 0.65 mm for 55 years of age group. The is introduced into the canal slowly. The area where the
apical terminus is preferred at the apical constriction. operator feels resistance is considered as the apical
constriction.
From a biological standpoint, the apical constriction
has the minimum blood supply. As the canal widens, The tactile method can be confirmed or reinforced
it develops broad blood supply. Extending the filling with paper point evaluation. After drying the canal, a
material beyond the apical constriction would induce paper point of appropriate size is inserted into the root
an inflammatory reaction. canal. It is kept in the root canal for ten seconds and
withdrawn. If the tip of paper point is wet or covered

15 Advantages
• Prevents impingement of periapical tissues (minimum
postoperative discomfort).
with blood, it indicates over extension of the working
length. The point of touch of blood is often taken as the
working length.

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 Working Length and Working Width 259

Advantages • The canal length is the length/distance from the

• No need for expensive gadgets apical exit of the canal to the reference point on the
• Easy manipulation. tooth crown. The working length should be
established 0.5–1.0 mm shorter than the measured
Disadvantages canal length (because the actual length of the tooth
• Any obstruction in the canal can be perceived as is 1.2 mm less than the radiographic image and the
apical constriction apical foramen is approximately 0.3 mm short of the
• Gloves may reduce tactile perception actual root tip).
• Not suitable for open apices and narrow canals In case the K-file is 1.0 mm shorter or longer than
the actual working length, the necessary adjustments
• Bifurcated canals also pose difficulties.
are made. If the difference is more than 1.0 mm,
2. Radiographic Method radiograph is repeated with the adjusted length.
The radiographic method is the most commonly used c. Ingle’s method: Ingle’s method is the most accepted,
method for determining the working length. easy to understand and accurate radiographic method.
The steps followed are:
Advantages
• Measure the tooth length on the preoperative
• Easy manipulation radiograph (Fig. 15.2a).
• Comparatively cheap. • Select an instrument with stop at that length (small
size files are preferred).
Disadvantages
• Place the instrument in the canal until the stop is at
• Exposing patient to radiation
the plane of reference point (incisal edge of anterior
• Superimposition of anatomic structure (common in teeth and cusp tips of posterior teeth are preferred).
bisecting technique) • Insert the selected file into the root canal with proper
• Three-dimensional objects are projected onto a two length stopper. Get another radiograph (Fig. 15.2b).
dimensional radiograph • Three possibilities can be evident. One, the tip of the
• Time consuming. instrument is up to the apical end of the root. Second,
Various authors have described different methods the instrument goes beyond the apical end (Fig. 15.2c)
of calculating tooth length using radiographs. and third, the instrument is falling short of the apical
end. In case of first possibility, the length remains
a. Coolidge and Kesel method: In this method, a suitable the same; in case of second possibility, the length of
diagnostic wire was inserted into the canal as accurately the instrument extending beyond the apical end is
as possible and a radiograph taken. After the radio- to be subtracted from the premeasured length. In case
graph, the wire was removed and preserved. An of third possibility, the length of the instrument
estimate of the tooth length can be obtained by the falling short is to be added to that length.
following formula:
The length so achieved is the length of the tooth.
length of wire image length of wire in actual Another 1.0–1.5 mm is to be subtracted to achieve the
= working length (Fig. 15.2d).
length of tooth image length of tooth in actual
In curved canals, as preparation proceeds, the
Earlier, best fixed 10 mm wire on the labial surface curvature gets straighten out and approximately
and took radiograph to measure tooth length. The 1.0 mm of the length may be lost further. Therefore,
method was discarded soon, as angulation and other the length should be reaffirmed in cases with curved
radiographic features gave incorrect results. canals.
b. Grossman method: Grossman utilizes comparatively When two canals superimpose in one radiograph,
easy method with reasonable accuracy. The steps two individual radiographs may be taken.
followed are: d. Radiovisiography (RVG): RVG system consists of
• The length of the tooth is measured from the four main components: An X-ray generator with special
reference point to the apex of the tooth on the timer, an intraoral sensor, a display processing unit and
radiograph. a printer.
• Establish the length on the diagnostic instrument,
i.e. K-file with a silicon stop. The instrument is placed
in the root canal and a radiograph is taken.
The X-ray generator is of the conventional type;
however, a special electronic timer provides accurately
controlled and short exposure times, as required.
15

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 260 Essentials of Endodontics

a b

c d

Fig. 15.2 Ingle’s method: (a) Measuring tooth length on preoperative radiograph; (b) File at predetermined length;
(c) File extending beyond the apical end; (d) File short of apical end

The intraoral sensor is the primary image receptor. tional techniques. They are then digitized and the
The intensifying screen fluoresces when X-rays fall upon images are converted to 256 gray scales. Traditionally,
it and the light is then conducted by the optical fibers additional radiographs, taken over time, are digitized
to a charge-couple device (CCD). The CCD detects the and a gray level value of 32 is added to the subsequent
pattern of light and translates it into an electrical signal, image to give the subtraction image a gray value in the
which is received by the display processing unit. middle of the dynamic range. As the subtraction image
The display processing unit consists of the electronic can be manipulated electronically, it is possible to
equipment, which digitizes, processes and stores the remove bony trabeculae and enhance the remaining
analog signal from the CCD. image, typically the tooth. This enables the clinician to
The display unit carries a number of controls, which visualize the tooth anatomy that would be difficult
allow manipulation of the image. The brightness and to capture by conventional radiographic means.
the contrast controls permit adjustment of the images Subsequently, diagnostic and working films can be
as with any TV set. The image can then be changed in manipulated by this system and then stored electroni-
two ways: cally.
• Reversal of gray scale
• Image enhancement by increasing the contrast and 3. Electronic Method
decreasing the latitude. The electronic devices provide quite accurate informa-
The original image remains stored and can be tion and also diminish the radiation exposure to the
returned to the screen at any time or can be printed out patient. These devices are useful for the pregnant, the
using a thermal paper. A zoom feature can be used to handicapped and such patients where placement of
produce an enlarged image. radiographs is extremely difficult.
The minimal inherent distortion of the RVG image Generally all electronic apex locators are identical in
is a clear advantage over conventional radiography. function; however, they vary in their mode of action.
e. Digital image processing: The development of this
type of image analysis enables radiographs to be TYPES OF APEX LOCATORS
digitized and manipulated electronically. A high Various types of apex locators are available depending

15 quality video camera, an analog to digital converter and

a computer form the basis of the hardware needed for
this type of image. Radiographs are taken using conven-
upon their principle of action. For convenience they are
classified as ‘generations’ (first generation, second
generation and so on).

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 Working Length and Working Width 261

a. First generation (resistance type, e.g. Dentometer, similar situation can occur in a tooth with a large
Sono explorer Mark I, Endo Radar) periapical lesion.)
b. Second generation (impedance type, e.g. Sono • These devices generate a current flow, which can be
explorer Mark II and III, Endocator, Formatron IV, detected by patients as a tingling sensation even
Digipex, Exact-A-Pex) under profound local anesthesia. This reaction seems
c. Third generation (frequency type, e.g. Root ZX, to be patient dependent and does not affect the
Endex, Formatron D10, NovApex) accuracy of the unit. Because of the current flow, the
d. Fourth generation (modified frequency type, e.g. use of these devices is contraindicated in patients
Raypex 4, ProPex, ipex) with cardiac pacemakers.
e. Fifth generation (blue tooth technology, e.g. Apex Many resistance type apex locators are available with
NRG-Blue, Medic-NRG, ProPex 2, Raypexe 5) a built-in pulp tester. Some of the units are required to
be switched and calibrated for use with the pulp testing
f. Sixth generation (adaptive type, e.g. DenApex).
probe, which is connected to the unit in place of the
apex locator leads. Other units are calibrated auto-
a. First Generation (Resistance Type) matically with the connection of the pulp testing probe.
The basic principle of these apex locators is: ‘The resistance
between the periodontal membrane and the oral mucosa is a b. Second Generation (Impedance Type)
constant value’. [The resistance between periodontium
These units operate on the principle that ‘there is electric
and oral mucous membrane in humans was constant
impedance across the walls of the root canal due to presence
at 6.5 kilo-ohms (current 40 mA). It measures opposition
of transparent dentin’. It measures opposite to the flow
to the flow of direct current or resistance.]
of alternating current or impedance. It is assumed that
Advantages the tooth is a long, hollow tube closed over at the end
The advantages of these apex locators are: (apex). The tooth also exhibits increase in electrical
impedance across the walls of the root canal, which is
• Perforations, either as a result of instrumentation or
greater apically than coronally. This phenomenon is
iatrogenic can be detected with these units.
caused by the presence of transparent dentin that begins
• Can operate with RC Prep. to form at approximately 17 years of age and continues
• Provides audible indication. throughout life. At the dentinocementum junction,
there is a constriction in the canal as well as an abrupt
Disadvantages
increase in the impedance across the root canal wall,
The disadvantages of these apex locators are: which the apex locator can detect. The unit indicates
• The root canal should be reasonably dry (excessive this constriction as the end position of the root canal
moisture or vital pulp tissues must be removed before on an analog meter dial.
accurate readings can be obtained). In case of Impedance type apex locators do overcome some
even minor amount of fluid in the canal, the device of the disadvantages of the resistance-based units
may indicate that the apex has been reached. (Fig. 15.3).
However, the units can operate in the presence of
RC Prep because it has a carbo-wax base that
provides sufficient electrical insulation for obtaining
correct readings.
• The file contacting a metal restoration and the
presence of defective restoration may also pose
problems. (The problem of the file touching a metal
restoration has been solved by the use of insulating
sleeves, which can be placed on the file to prevent
short circuits. The defective restoration should be
removed prior to the use of these gadgets.)
• Most of the units provide a digital measurement of
the distance from the endpoint of the current position
of the file tip in millimeters. (In case the file do not
touch periodontal tissue apically as in a tooth with
an open apex, it is not possible to detect endpoint. A Fig. 15.3 Foramatron (impedance type apex locator)
15

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 262 Essentials of Endodontics

The use of insulated canal probe eliminates the need The file should fit the size of the canal snugly. If a
of having a reasonably dry canal. Although this system canal is being retreated then it is important to remove
enables the machine to operate in a fluid environment, all the existing gutta-percha as it has insulating
the additional thickness that the insulation adds to the properties that may cause inaccurate readings.
probe diameter can restrict the passage of the probe to
the apex. Apart from locating the apical constriction, Technique
this type of device is able to detect bifurcated canals, The technique for using a frequency based apex locator
lateral canals and perforations. The ability of the unit is as follows:
to function in young teeth without transparent dentin • Turn on the device and attach the lip-clip near the
and in teeth with open apices, is however variable. arch being treated. Place a size 15 file into the
reamer/file holder. A 25 mm long plastic file is used
c. Third Generation (Frequency Type) so that enough metal should protrude through the
The frequency type apex locator operates on the tooth to attach the file clip. Insert the tip of the file
principle that ‘there is a maximum difference of impedance approximately 0.5 mm into the tooth being treated.
between electrodes depending on the frequencies used Adjust the control knob until the reference needle is
(measures the impedance of tooth at two different centered on the meter scale and produces audible
frequencies)’. beeps. Set the holder aside until needed to record
The unit uses a lip clip and is calibrated by insertion the measurement.
of a file into the coronal position of the canal (Fig. 15.4). • Access cavity is prepared and the canals are
At the coronal portion, the impedance difference thoroughly irrigated. Irrigate the canal and remove
between the two frequencies is almost constant. As the any pulp tissue and debris.
file is advanced apically, the difference between the • The length can be estimated provisionally from the
impedance values begins to differ greatly and is preoperative radiographs. The canals should be
maximally different at the apical constriction. slightly wet with irrigant. Hydrogen peroxide can
The unit can operate in an electroconductive be used instead of sodium hypochlorite, as it is a non-
environment using K-files, which is a major advantage ionic liquid. If bleeding from a vital pulp extirpation
over all other types of apex locators. Secondly, the unit is excessive, dry with paper points until it recedes.
can operate in the presence of pus and pulpal tissues. • Insert the file slowly into the canal until the reference
As this type of unit uses conventional files, the problems needle moves from the extreme left to the center of
of coated probes in the impedance type of device are the scale and the alarm beep sounds.
overcome. Accurate calibration of the unit is important, • A radiograph with the file placed at the length indicated
and the file must touch the coronal portion of the canal by the apex locator can be taken to reassure the
when this step is being performed. Failure to ensure findings. If the suggested length is considerably
these steps results in measurement errors. shorter or longer, it is possible that the preoperative
films and/or the apex locator would be inaccurate.
The process is repeated till accuracy is achieved.
d. Fourth Generation (Modified Frequency Type)
The fourth generation devices measure and compare
the complex electrical characteristic feature of the root
canal through two or more frequencies of electrical
impulses (Fig. 15.5).
The disadvantage of these devices is that they need to
perform in relatively dry or in partially dried canals.
In the presence of exudates or blood this method
becomes inapplicable.
e. Fifth Generation (Bluetooth Technology)
To overcome disadvantages of fourth generation apex
locators, a measuring method based on comparison of

15 Fig. 15.4 Root ZX (frequency type apex locator)

the data taken from the electrical characteristics of the
canal and additional mathematical processing, was
developed. Apex locators of this type are fifth generation

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 Working Length and Working Width 263

devices (Fig. 15.6a to c). These devices perform well in

the presence of blood and exudates; however, it is
difficult to operate in dry canals. Addition of liquid is
required for accurate performance.

f. Sixth Generation (Adaptive Type)

A steady algorithm for adapting the difference of
frequencies in the root canal is created to determine
the canal length depending on the moisture charac-
teristics (the device adapts the measuring method for
either a dry or a wet canal).
The measuring mode provides for graphic informa-
tion to be displayed on the monitor. The adaptive apex
locator can retrieve audio information through beep or
speech massage.
Fig. 15.5 ProPex (modified frequency type apex locator) The device can measure moisture in the canal. The
message ‘apex’ signifies the tip of the instrument is
touching the physiological narrow part and the message
‘over’ means the tip has passed the anatomical foramen.
DenApex, a sixth generation multi-frequency
operating system, that gives accurate readings in both
dry and wet conditions has been introduced (Fig. 15.7).
It has large LCD display with time graphic and
adjustable angle of view. The moving trace of file in
the canal can also be viewed.
The advantages and disadvantages of different types
of apex locator are summarized in Table 15.1.
a The problems faced during use of apex locators, the
causes of said problems and their solutions are
tabulated in Table 15.2.

Advantages of Apex Locators

• The major advantage is that it provides an objective
information with a high degree of accuracy about
the location of the apex and the point where the
apical termination should end.
b

15
c

Fig. 15.6 Bluetooth technology apex locators: (a) Raypex 5;

(b) and (c) MedicNRG Fig. 15.7 DenApex (adaptive type apex locator)

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 264 Essentials of Endodontics

Table 15.1 Advantages and disadvantages of different types of apex locators

Apex locator Advantages Disadvantages
First generation • Easy to operate • Requires dry environment
(Resistance type) • Digital read-out • Defective restorations may pose problems
• Audible indication • Patient sensitivity
• Uses K-type files • Requires calibration
• May incorporate pulp tester • Requires a lip-clip with good contact
• Perforations can be detected • Perforation near apex may give false reading
• Operates with RC Prep • Not indicated in patient with cardiac pacemaker
Second generation • Operates in a fluid environment • Difficult to operate
(Impedance type) • Analog meter • No digital read-out
• No patient sensitivity • Requires coated probes
• No lip-clip required
• Operates with RC Prep
Third generation • Easy to operate • May be short circuited
(Frequency type) • Operates in a fluid environment • Requires a lip-clip with good lip contact
• Uses K-type files • Each canal is to be calibrated
• Analog readout • Sensitive to extra fluid in the canal (irrigant
• Audible indication should be in the canal and not in the
• Rechargeable chamber)
Fourth generation • Multiple frequencies employed • Need to perform in relatively dry canal
(Modified frequency type)
Fifth generation • Additional mathematical processing • Difficult to perform in dry canals
(Bluetooth technology) comparing electrical characteristics
• Perform better in presence of blood
and/or exudate
Sixth generation • Useful in both dry and wet canals • Clinical accuracy is yet to be established
(Adaptive type) • Small size is easy to operate
• Movement of the instrument displayed
on the monitor

Table 15.2 Problems, causes and solution with the use of apex locators
Problem Possible cause Solution
Apex locator has continuous high • Machine remained ‘on’ overnight. • Turn off and let rest
pitched whining sound • Battery is running low • Replace battery
When the file is introduced, the • Too much tissue in the canal • Débride canal and the instrument
indicator moves erratically • Too much moisture in the canal • Dry with paper points
• Perforation • X-ray to evaluate/seal perforation
• File is too far from foramen • Put file closer to the tip of the tooth
File is in but indicator does not • Blockage is present or canal is calcified • Bypass blockage with EDTA/file
move apically
• Instrumentation finished, but apical plug • Clear apical plug (area)
present
• Lip-clip not properly placed • Readjust lip-clip
• Connection to file holder faulty • Buy new wire leads

• It is especially important where radiographs are not • Useful in patients who gag easily.
sufficient to interpret the working length. Such a • Useful in handicapped patients.
situation often exists in maxillary molars where
• Excellent for detecting apical and chamber perforations.
radiopaque structures of the molar process or the
• Can verify the level at which the root is resorbed.
15 floor of the maxillary sinus may superimpose on the
apices of the teeth or mandibular tori may interfere
in mandibular bicuspids.
• Can determine if two canals join apically. Insert one
file using the apex locator to determine the working

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 Working Length and Working Width 265

length. Then place a second file in the adjacent canal Disadvantages of Apex Locators
and if the files contact each other along the root, the • The overall accuracy is 90%.
apex locator will read as if the second file has reached
• Most apex locators utilize a 9V battery. If the 9V
the apex. This will indicate that the two canals lead
battery drops below approximately 7V, inaccurate
into a single foramen.
readings will result.
• Useful to determine whether the apical bridge
formation is complete in apexification procedures. • All apex locators do not work in the presence of
• The exact location of horizontal root fracture can also sodium hypochlorite, anesthetic solution or any
be detected. other ionized solution.

Table 15.3 Working length determination: Comparison of apex locators with other modalities
Author (year) Study sample Apex locator used Aim of study (type) Inference
Busch et al 77 (46 vital + 26 Sono-Explorer Evaluated accuracy of the Accurate reading for both vital
(1976) necrotic) device in working length and necrotic teeth
measurement (in vitro study)
Berman et al 29 (24 mature + 5 Nesono-D Evaluated accuracy of the Accurate in mature teeth
(1984) immature teeth) device in working length (doubtful in immature teeth)
measurement (in vitro study)
Wu et al 20 (single rooted) Sono-Explorer Evaluated accuracy of the Clinically acceptable accuracy
(1992) Type III device in working length
measurement (in vitro study)
Himel et al 96 Formatron-IV Compared the accuracy Apex locators were not
(1993) of apex locators with accurate
radiography (in vivo study)
Frank et al 185 Endex Compared the accuracy Apex locator was comparable
(1993) of apex locators with with radiographic method
radiography (in vivo study)
Shabahang et al 26 Root ZX Evaluated accuracy of the Clinically acceptable accuracy
(1996) device in working length
measurement (in vitro study)
Stavrianos et al 85 Raypex-5 Evaluated accuracy of the Apex locator was accurate
(2007) device in working length
measurement (in vitro study)
Ounsi et al 39 (single rooted) Root ZX Evaluated accuracy of the Could not detect apical
(1999) device in working length constriction, accurate for
measurement (in vitro study) apical foramen
Martinez Lozano 70 Apit Comparison of apex locator No significant difference
et al (2001) and radiography in working
length determination
(in vitro study)
Subramanian 20 Formatron D10 Comparison of apex locator No significant difference
et al (2005) and radiography in working
length determination
(in vitro study)
Smadi, L 151 Tri Auto2X Comparison of apex locator Apex locator was effective; no
(2006) and radiography in working need of radiography
length determination
(in vitro study)
Krajezar et al 70 ProPex Comparison of apex locator Apex locator was more
(2008) and radiography in working accurate

15
length determination
(in vitro study)
(Contd…)

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 266 Essentials of Endodontics

Table 15.3 Working length determination: Comparison of apex locators with other modalities (Contd.)
Author (year) Study sample Apex locator used Aim of study (type) Inference
Cianconi et al 101 Endex Comparison of apex locator Apex locator was more
(2010) Propex II and radiography in working accurate
length determination
(in vitro study)
Zand et al 75 Root ZX Comparison of apex locator No significant difference
(2011) and radiography in working
length determination
(in vitro study)
Chougute et al 13 (primary) Dentaport ZX Comparison of apex locator Apex locator was more
(2012) and radiography in working accurate
length determination
(in vitro study)
Sivadas et al 30 (primary molars) Root ZX Comparative evaluation of No significant difference. Both
(2013) Root ZX and conventional are comparable
radiography to measure
working length in deciduous
molars (in vitro study)
Lucena et al 150 RayPex-6 Comparative evaluation of Apex locator was more
(2014) RayPex-6 and CBCT to accurate than CBCT
measure accurate working
length (in vitro study)
Singh et al 153 (single canal) RayPex-5 Comparative evaluation of Apex locator was comparable
(2015) RayPex-5 and conventional to radiography
radiography to determine
working length (in vitro study)
Carneiro et al 40 (single rooted) JoyPex-5 Comparison of JoyPex-5 Apex locator was more
(2016) and manual method to accurate
determine working length
(ex vivo study)
Jafarzadeh et al 22 canals Root ZX (Mini) Comparison of apex locator Apex locator was more
(2017) (C-shaped) and radiography (CBCT) in accurate
working length determination
of c-shaped canals
(in vitro study)
Bhat et al 30 (primary teeth) iPex Comparison of iPex and Both are comparable
(2017) conventional radiography to
determine working length in
primary teeth (in vitro study)

Various authors have evaluated apex locators and diameter at the constriction as well as other areas of
many others have compared apex locators with other the root canal are important for proper cleaning and
means to determine accurate working length, both in obturating the pulp spaces (Fig. 15.8a and b).
deciduous and permanent teeth. The selected few Apical enlargement at working length referred to the
studies are summarized in Table 15.3. sequential widening of apical constriction area without
its destruction.
ENDODONTIC WORKING WIDTH The horizontal dimensions of the root canal system
at apical constriction and other levels of root canal are
The extent of apical enlargement is typically based on designated as ‘working width’.
an estimate of initial canal size as determined by the In a relatively round canal, the horizontal dimensions
size of hand file that ‘binds’ at the working length. The are usually, the same but in oval, flat and other canals,
tactile detection of apical constriction and apical file these dimensions vary.

15
size determination depend on the assumption that the The working width is important at apical constriction
canal is narrowest in the apical region. However, this (working length), 1.0 to 3.0 m short of working length,
may not be true in all cases. The configuration and at the centre of canal and also the coronal aspects.

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 Working Length and Working Width 267

a a

b b
Fig. 15.8a and b Variation in root canal configuration in Fig. 15.9a and b Root canal width (different sections)
mesiodistal and labiolingual view

Three clinical parameters are to be taken into a. Canal shape: Oval/flat canals pose clinical difficulty
consideration during root canal preparation. in estimating initial working width; however, in round
a. Length of canal canals it is easy to assess (Fig. 15.9a and b).
b. Taper of preparation b. Canal length: Longer the canal, greater is the frictional
c. Horizontal dimension of the preparation, especially resistance which may affect the clinician’s tactile
at its most apical extent. sense for measuring the initial working width.
The apical enlargement depends on this first file that c. Canal taper: The discrepancy of taper between the
binds at the apical constriction. However, it is gauging instrument and the canal may lead to an
established that the first file that bound at working early instrument engagement in the canal, assuming
length did not accurately reflect the diameter of the the same as apical binding.
canal at the apex. Such inaccuracy and discrepancy can d. Canal curvature: The gauging instrument may feel the
frictional resistance while intercepting curvatures,
be due to various morphologic and procedural factors
which can lead to false estimation of working width.
such as canal shape, canal length, curvature of canal,
e. Canal obstructions: The pulp stones, denticles and
coronal interference, etc.
reparative dentin, etc. may create problems in
Factors Affecting Determination of assessing the initial working width.
Initial Working Width Clinical Suggestions
The rigidity, flexibility and taper of the instrument used • Before working width determination, it is suggested
for determining initial working width can affect to widen the orifices and achieve coronal flaring so that
accuracy. The discrepancy between taper of canal and the interferences with tactile sensation are minimized.
gauging instrument can alter the tactile sensation and
may lead to wrong judgment. The factors affecting
determination of working width are:
• The adequate instrument having maximum flexibility
and minimal taper may be selected to avoid inter-
ference.
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 268 Essentials of Endodontics

of the presence of necrosed dentin, while other cases

may not require the enlargement at all.
A few authors have advocated minimal apical pre-
paration (size 20 or 25) to prevent apical transportation
or zips. Another author tried to standardize the apical
preparation, by advocating fixed criteria for the given
teeth. For example, maxillary central incisor is to be
prepared up to size 80 and mesiobuccal and mesio-
lingual canals of mandibular molars to be prepared up
to size 25. This school of thought was also not acceptable
since unnecessary enlargement of the canal is never
advisable; secondly each case warrants the enlargement
depending upon the amount of necrosed dentin present
coupled with chronicity of the disease. If necrosed
a b
dentin is present even after enlarging to size 80 or so in
maxillary central incisors, there is need to enlarge the
Fig. 15.10a and b Root canal obturation: a. Satisfactory same till the necrosed dentin is comprehensively
obturation in mesiodistal view, b. part of root canal not
removed. And also, if the tooth is vital with no sign of
prepared and obturated (labiolingual view)
necrosed dentin, there is no need to enlarge the canal
If any part of root canal remains unprepared, it can three times even.
harbor a lot of microbes, which will ultimately lead to Summarily, the root canal is to be enlarged depending
failure of endodontic treatment (Fig. 15.10a and b). upon the amount of substrate present, i.e. necrosed dentin.
However, the overpreparation of canal may unnecessarily It is established that the apical preparation be kept
remove the sound tooth structure, hence weakening the minimum, which minimizes the potential for creating
root. It increases the risk of fracture and also increases procedural errors and provide better control of obturat-
chances of procedure errors, such as perforation, ing material. However, larger apical preparation aid in
ledging, transportation, etc. better elimination of bacteria and cleaner canals due to
The reduction in intracanal bacteria during root canal better penetration of the irrigant into this region.
preparation with and without apical enlargement has
been compared. It is established that the bacterial BIBLIOGRAPHY
reduction in both is insignificant.
1. Ahmad IA. Rubber dam usage for endodontic treatment: a
review. Int. Endod. J.:2009; 42:963–972.
Need to enlarge Apical Constriction Area
2. Alothmani OS, Friedlander LT and Chandler NP.
The apical constriction or the cementodentinal junction Radiogrpahic assessment of endodontic working length. Saudi
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instrumentation and obturation. Theoretically, it is the 3. Anthony W and Robert H. The influence of Sodium
narrowest part of the canal and a junction where the Hypochlorite irrigation on the accuracy of the root ZX
pulp ends and periodontium begins. electronic apex locator. J. Endod.: 2002; 28:595–598.
The apical constriction may not be round. Generally, 4. Asako O, Takamoto Y, Chihiro K and Hideaki S. Electronic
it is either oval or irregular in shape. When débriding detection of root canal constrictions. J. Endod.: 2002; 28:
and preparing this area with root canal instruments, 361–364.
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of this area. in endodontics – an overview of recent advances. Int. J. Clin.
The apical portion of the root canal system can retain Dent.:2015; 6:319–330.
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dontic treatment failures. evaluation of accuracy of new generation electronic apex
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constriction area of the root canal to three sizes larger Dent.:2017; 10:34–37.
than the first file bound. However, other authors were 7. Busch LR, Chiat LR, Goldstein LG, Held SA and Rosenberg

15 of the view that the three sizes larger preparation is

not relevant in all the clinical cases. Certain cases may
warrant the enlargement more than three sizes, because
PA. Determination of the accuracy of the Sono-Explorer for
establishing endodontic measurement control. J. Endod.:
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8. Caldwell JL. Changes in working length following instruments 23. Mosleh H, Khazaei S, Razavian H, Vali A and Ziaei F.
of molar canals. O. Surg., O. Med., O. Path.:1976; 41:114–118. Electronic apex locator: A comprehensive literature review-
9. Carneiro JA, deCarvalho FM, Marques AF, Sponchiado Jr EC, Part I: Different generations, comparison with other
Garcio FR and Gonclaves LCU. Comparison of working length techniques and different usages. Dent. Hypothesis:2014;
determination using apex locator and manual method – ex 5:84–97.
vivo study. Dentistry and Medical Research:2016; 4: 24. Nekoofar MH, Chandi MM, Hayes SJ and Dummer PM. The
39–43. fundamental operating principles of electronic root canal
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minimum canal walls widths in c-shaped roots of mandibular 25. Ounsi HF and Naaman A. In vitro evaluation of the reliability
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11. Chougule RB, Padmanabhan MY and Mandal MS. A 32:120–123.
comparative evaluation of root canal length measurement 26. Singh D, Tyagi SP, Gupta S and Jain A. Comparative
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Endod. J.:2004; 37:425–437. major and minor foramen diameters on apical electronic
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18. Jou YT, Karabucak B, Levin J and Liu D. Endodontic working reliability of working length determination by gold reciproc
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Rodriguez MD. Accuracy of working length measurement: electronic apex locators. Int. Endod. J.: 2007; 40:133–138.
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Rodriguez MP. Accuracy of working with measurement: 34. Zafarzadeh H, Beyrami M and Forghani M. Evaluation of
electronoc apex locator versus cone beam computed conventional radiography of an apex locator in determining
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length. Dent. Cl. North Am.: 1992; 36:293–307. 35. Zand V, Mokhtari H, Lotfi M, Reyhani MF, Sohrab A and
22. Morroquin BB, Frajlich S, Goldberg F and Willershausen B. Tehranchi P. Accuracy of working length determination with
Influence of instrument size on the accuracy of different apex root ZX apex locator and radiography: An in vivo and ex
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15

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Chapter
16
Cleaning and Shaping of
Root Canals

The earlier concept of preparation of root canals as termed ‘concept of flow’, facilitating placement of
envisaged by Grossman and others is being modified obturating materials and also their removal, if need be.
as cleaning and shaping in the past couple of years.
The basic idea of preparation of root canal is to remove OBJECTIVES OF ROOT CANAL PREPARATION
all organic and inorganic debris and microorganisms
The objective features of root canal preparation can be
from the root canal system along with the substrate
mechanical and biological.
which harbors the microorganisms. The preparation
also shape the root canal walls, facilitating placement Mechanical objectives
of medicament/obturating material into the root canal • Continuously tapering funnel from the apex to the
spaces. access cavity.
The term ‘biomechanical preparation’ as described by • Cross-sectional diameter should be narrowest
Schilder, involves biological and mechanical objectives apically.
in preparation of root canals. • Preparation should flow with shape of the original
It has been emphasized that tooth root rarely canal.
contains a simple canal that can be cleaned in a hollow • Position of the apical foramen should not change;
tube manner; rather, it is a complex system containing maintaining the original position of the foramen.
accessory/lateral canals, fins/apical delta and other • The apical opening should be maintained as small
anatomical variations. A few of these anatomical as practically possible.
intricacies may not be accessible to instrumentation and
hence some chemical agent is necessary to clean these Biologic objectives
areas (concept of chemomechanical preparation). The • All instrumentation to be confined within the root
penetration of the chemical agent deep into the canal canal.
system to aid in flushing and dissolving organic debris • Necrotic debris is not to be forced beyond the
requires prior mechanical preparation. The shaping is foramen.
achieved prior to cleaning. Therefore, the term ‘shaping • Removal of substrate harboring microorganisms
and cleaning’ is gaining popularity instead of ‘cleaning from the root canal space.
and shaping’; however, the conventional term ‘root canal • Creation of sufficient space for intracanal medica-
preparation’ is used in routine. ments.
Complete removal of organic contents of the entire
root canal space followed by abundant irrigation has Goals to Achieve
always been emphasized. The axiom ‘what comes out The goals of root canal preparation, which the clinician
is more important than what goes in’ forms the basis should achieve are:
for successful endodontics. It is established that shaping • Removal of vital and necrotic tissue from the main
must not only be carried out according to anatomy of root canal(s).
each canal but also in relation to the technique and • Creation of sufficient space for irrigation and
material for final obturation. The basic shape of the medication.
prepared canal should be a continuously tapering • Preservation of the integrity and location of the apical
funnel simulating the shape of the root canal. This was canal anatomy.

270

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 Cleaning and Shaping of Root Canals 271

• Avoidance of iatrogenic damage to the root structure.

• Preservation of sound root dentin to allow long-term
function of the tooth.
• Facilitation of root canal filling.
• Avoidance of irritation and/or infection of the
periradicular tissues.
All these features aid in promotion of healing and
prevention of periradicular disease.
Before preparing the root canal, the concept of
‘working length’ and ‘working width’ should be
understood (Chapter 15).

Instrument Motions during Root Canal Preparation

Root canal instruments utilize various motions during
root canal preparation. The commonly used motions Fig. 16.2 Reaming motion (cutting achieved during
are: retraction)

a. Watch-winding motion: This motion is used to c. Filing: In this motion, the instrument is placed to the
explore the canal at the beginning before carrying out
desired length applying pressure against the walls of
the coronal flaring. In this motion, a small K file,
the canal. The instrument is withdrawn while
referred to as path finders (number 06 or 08) is used to
maintaining the pressure and without turning; the
negotiate the working length with quarter-turn
cutting is achieved during withdrawing. K-files are
rotational movement (Fig. 16.1).
more popular; however, H-files perform filing
b. Reaming: Reaming is carried out to produce a round efficiently (Fig. 16.3).
tapered preparation and is preferred in straight canals.
The purpose of reaming is to enlarge or taper pre- d. Circumferential filing: In case the file cannot contact
existing spaces. The reamers perform the action of all walls of canal simultaneously (large diameter
cutting dentin by being inserted into the canal, twisted canals), circumferential filing is carried out; i.e. filing
clockwise 1/4th to ½ turn, engaged their blades into motion performed around all the walls circum-
dentin and finally withdrawn, i.e. penetration, rotation, ferentially (Fig. 16.4). Circumferential filing facilitate
retraction (cutting is achieved during retraction) removal of infected dentin thoroughly from the root
(Fig. 16.2). canal walls.

Fig.16.1 Watch winding motion Fig. 16.3 Filing motion Fig. 16.4 Circumferential filing
16

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 272 Essentials of Endodontics

e. Anticurvature filing: Anticurvature filing motion is

used to prevent the excessive removal of dentin from
thinner root sections in curved canals, thus reducing
the risk of perforation. The basic example is a mesial
root of mandibular molars where the furcation side
(danger zone) has less dentin thickness than the mesial
side (safety zone) (Fig. 16.5). In this technique, pre-
curved hand files are used to prepare the canal at the
danger zone. Safety H-files (flattened edges and dull
at one side) are used for filing the danger zone area.
Recently, instruments with advanced flexibility are
developed to prepare danger zones of the root canals,
without any possibility of strip perforation.
f. Rotary: Different rotary files are available; files are
continuously rotated in the root canal (not more than
5 seconds at one time) to achieve requisite preparation.
Rotary instrumentation have revolutionized the root
canal preparation protocol.

Root Canal Preparation: Concepts/Terms

Fig. 16.6 Apical gauging (assessing apical diameter)
a. Apical gauging: Apical gauging implies measuring/
assessing the apical diameter of the canal, where the • The gauging instrument is inserted straight in and
instrument fits snuggly and resist further apical straight out, without any rotation.
movements. This ensures apical terminus of the
prepared canal (Fig. 16.6). • 17% EDTA as irrigant is used to remove the smear
layer, facilitating better gauging.
• Ni-Ti instruments are preferred for gauging because
of their flexibility (especially in curved canals). • Endogauge, a gadget, is available with holes of
different diameters for confirming the diameter of
the instrument and the gutta-percha as well.
• Gauging is carried out after root canal preparation;
master apical file is preferred.

b. Apical tuning: Apical tuning implies a confirming

parameter, whereby the apical diameter of the master
apical file represents the true diameter of the apical
configuration of the root canal.
• Tuning is a clinical activity of recapitulating using
series of successively larger instruments.
• Clinically, the file that goes full length represents the
‘true apical diameter’ of the canal (each successive
larger instrument backs out of canal with an interval
of 0.5 mm).

c. Patency filing: The technique of patency filing

involves passively inserting a small sized (size 08 or 10)
file, 2.0 mm beyond the apical constriction. Buchanan
first described the concept of patency filing; defined
as ‘small K-file, which passively moves through the apical

16 Fig. 16.5 Depiction of safe zone and danger zone

(anticurvature filing: Mandibular molar)
constriction without widening the apical constriction’
(Fig. 16.7). No preparation is carried out at this
stage.

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 Cleaning and Shaping of Root Canals 273

Fig.16.7 Patency filing Fig. 16.8 Apical control zone

i. Favoring patency filing constriction) affects the rheology of gutta-percha and

• Cleans apical constriction/foramen area provides resistance form against the condensation
• Maintains working length pressure of obturation (coronal to constriction,
exaggerated taper is given, which provides resistance
• Prevents packing of debris at the apical constriction
end against condensation pressure and also prevent
extrusion of debris out of periapex). It facilitates ‘apical
• Help keeping apical zone area free of micro-
cleaning’ (maximize débridement of apical one-third
organisms.
area, especially in curved canals) (Fig. 16.8).
ii. Disfavoring patency filing This area, initially proposed by Roane for balanced
• May push debris into periapical areas force technique, should be evaluated with smaller files
• May push microorganisms into periapical area (glide path) prior to instrumentation.
• May injure the configuration of apical constriction.
Points to remember
d. Apical scouting: Apical scouting, similar to apical
• 75% of the instrument that bound in the canal at working
gauging, implies determining the cross-section
length, contact only one wall; the other 25% do not
diameter of the apical third of the root canal. Smaller
contact; Inference is ‘The first file that bind may not
sized instruments are used to assess the diameter at
reflect the diameter at working length’.
the apical end.
• The major foramen of all teeth are deviated from the
e. Coronal scouting: The process of determining the anatomic apex (average distance between anatomic apex
cross-sectional diameter of coronal 2/3rd of the root and foramen is 0.59 mm).
canal. Appropriate size of the file is used to assess the • Average distance from apical foramen (major diameter)
diameter of the root canal at the coronal orifices and to cementodentinal junction (apical constriction) is
also within the coronal 2/3rd area. 0.72 mm; whereas, width of cementodentinal junction
Scouting files also analyze the site of curvature in is 0.189 mm (size increases with age).
the root canal (how far the canal is straight from coronal
opening and from where the curvature begins).
TECHNIQUES OF ROOT CANAL PREPARATION
f. Apical stop/apical seat: A matrix of dentin or other The techniques of root canal preparation can be divided
material at the apical end of root canal preparation. into two groups:
Apical seat implies lack of complete barrier, but
presence of constriction; whereas, apical stop means A. Apical-coronal Techniques
complete barrier at the preparation end.
In apical-coronal techniques, the canal is prepared
g. Apical control zone: The ‘apical control zone’ is the
mechanical alteration created in the apical third of the
root canal. This area (around 1.5 mm from the apical
starting from apical end and sequentially increasing in
size coronally, until the final shape is achieved. The
shape is refined from apically up to coronally.
16

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 274 Essentials of Endodontics

Root canal preparation: Key points

• Visualize and analyze the tooth to be treated
• Customize the access cavity preparation
• Analyze pulp anatomy of root canals
• ‘Read’ radiograph thoroughly
• Concentrate on each canal separately
• Proceed with delicacy; go slow, have patience
• Anticipate preparation of shape required
• Use sterilized, new instruments; discard old a b c d
instruments
• Do not force instruments; use gentle pressure Fig. 16.9 Procedural errors: (a) Non-uniform force in curved
canal (b) Ledge formation (loss of working length); (c) Apical
• Use ample and continuous irrigation transportation; (d) Perforation
• Carry out preparation in one sitting.
standardized technique, especially for the preparation
The routinely used apical-coronal preparation of curved canals; however, the technique remained
techniques are: suitable for straight canals.
a. Standardized technique The technique prepares the canal using files with a
b. Step-back technique push-pull/watch-winding motion leading to a wider
c. Modified step-back technique taper than that produced in the standardized technique.
d. Balanced force technique. The wider taper facilitates the obturation, precisely with
lateral condensation technique.
a. Standardized Technique
Step wise procedure
The standardized technique, introduced by Ingle,
involves determining working length followed by The steps are described for straight canals; the modifica-
placement of smallest size file/reamer to the full tions for curved canals are described subsequently:
working length. The instrument is rotated clockwise i. Determine the working length.
to engage dentin and then withdrawn. The instrument ii. Insert the file that precisely fits to the full working
is wiped clean and then reinserted till it became loose. length. File circumferentially until the next size file
The canal is enlarged three times the size of first reaches the full working length. Simultaneous
instrument that binds at apex or until clean white dentin irrigation with suitable irrigants is mandatory.
shavings are seen in the apical few millimeters of the iii. The process is repeated until two sizes large file can
instrument. reach the working length. Each next size file should
The canal shape so produced matches the last be introduced only when the previous file is just
instrument used. This technique works well in straight loose at the working length (Fig. 16.10a). This
canals; however, it is unsuitable for curved canals. completes the preparation of apical area. (First three
The technique cannot débride canals with complex steps are also designated as phase I of the preparation)
shapes; the obturation of such areas relies on the sealers (Fig. 16.10b).
only. The technique is also associated with procedural iv. The preparation is now flared by using the next size
errors (Fig. 16.9) like ledging, zipping, perforation, loss file 1.0 mm shorter than the previous file until it is
of working length especially in case of curved canals loose. After each filing, it is paramount to
(as the instrument size increases it becomes more rigid). recapitulate, i.e. the smaller file is introduced again
The technique is no longer followed, since the three to full working length under copious irrigation. The
times enlargement is not sufficient in some case, and process of recapitulation ensures canal patency till
in other cases, it might not be necessary. The presence the preparation continues. Recapitulation is
of clean dentin shavings is also not a confirmative beneficial as:
parameter of root canal preparation. • Prevent blocking the canal with dentinal debris
• Smoothen the walls of the canal
b. Step-back Technique • Facilitate subsequent insertion of larger

16 The step-back technique is also known as telescopic or

serial root canal preparation. This technique was
devised to overcome the shortcomings of the
instrument as the preparation proceeds.
v. Again the next size file is introduced 1.0 mm shorter
than the file used at step iv. The recapitulation is

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 Cleaning and Shaping of Root Canals 275

a a b
Fig. 16.11 Step-back technique: (a) Apical refining,
(b) Coronal refining (Phase III)

b
Fig. 16.10 Step-back technique: (a) Apical preparation;
(b) Root canal preparation (Phases I and II)

also repeated. This process is repeated and the

preparation is completed in steps from apical end
to coronal end.
(The steps iv and v are designated as phase II of the
preparation).
vi. The coronal portion is then refined with Gates
Glidden drills and the apical portion is refined with Fig. 16.12 Step-back technique (modification of instrument
for curved canals)
the same size file as used for apical preparation
(master apical file). Usually a file of the same number Advantages
as the master apical file is used for this purpose to
remove the irregular surface created by the step- • Greater flare facilitate dense obturation
back procedure as well as to produce a smooth • Less chances of trauma to periapical tissues
tapering canal preparation (Fig. 16.11a and b). • Allows effective removal of debris
[This step is phase III, the refining phase; a few authors • Apical matrix at apical area minimizes chances of
have further modified as refining phase A (coronal over instrumentation and subsequently overfiling.
refining) and refining phase B (apical refining)]. (This technique is likely to achieve cleaner canals and
Modification for curved root canals allows better control over the apical preparation than the
standardized technique.)
i. Smaller files are precurved as per the curvature;
instrument step is adjusted accordingly. Disadvantages
ii. In narrow canals, sequential enlarging is modified • May lead to apical blockage (debris collected below
by cutting 1.0 mm tip of the file (file 10 can be made the apical constriction area)
file 12, 13 and so on). These intermediate filing
help negotiating narrow canals more effectively • Alteration of working length
(Fig. 16.12). • Tendency for canal deviation when using the larger
iii. The files should not bind at any stages during canal
preparation.
inflexible instruments (Hour-glass preparation)
• The H-file may cause overflaring or strip-perforation.
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t.me/Dr_Mouayyad_AlbtousH
 276 Essentials of Endodontics

c. Modified Step-back Technique out of the wood, but if you place a screw into the wood
In modified technique, the apical area is prepared in with a slight clockwise motion and then turn counter-
routine using circumferential filing. After the apical clockwise as you push down, the screw will strip the
preparation is complete, the step-back procedure is threads it originally cut into the wood. The same thing
initiated 2.0 to 3.0 mm coronal to the apical end. This happens in a root canal.
gives a parallel and round form in the apical area. Such Stepwise procedure (Fig. 16.13)
a preparation provides tight fitting gutta-percha in the Place the file passively in the root canal and proceed as:
apical 2.0–3.0 mm of the prepared canal. The rest of the
Step I. Turn the file one quarter turn clockwise, which
canal is flared and is obturated conventionally.
seats the file with a slight screwing in motion. This
Advantages motion should be as limited as possible.
• Minimal chances of apical transportation Step II. Move the file three-quarter turn counter-
• Better adaptation of gutta-percha at the apical area. clockwise; hold it in place with inward pressure. As
the shear strength of the dentin is exceeded, a stripping
Disadvantages
occurs and a slight click is heard.
• Debris may accumulate at apical-third area
• Irrigating the apical area is difficult. Step III. Advance apically (light apical pressure).
Step IV. After the file is free, it is removed from the
d. Balanced Force Technique canal in clockwise rotation (Fig. 16.14).
Balanced force technique, popularly known as Roane’s • These movements are repeated as the instrument is
technique, was introduced in 1985 by Roane. The advanced up to the working length.
objectives of the technique are: • Continuous irrigation with suitable irrigant is
• Reduce instrument breakage mandatory.
• Minimize canal straightening • Coronal access can be flared with Gates Glidden drills.
• Eliminate apical zipping. Roane initially proposed an ‘Apical control zone’ in
The balanced force technique utilizes Flex-R file (a balanced forced technique; wherein, the canals are
file made from diamond shaped wire with a non-cutting prepared to a predesigned dimension. The three sizes
tip), a modified version of K-file (conventional K-file are recognized, i.e. 45, 60 and 80 according to the size
can also be used). of the apical preparation. These dimensions refer to the
The Flex-R is a triangular cross-section file which is size of the file used at the third step-back and not the
ground in a helical position rather than in a vertical size of the master apical file.
orientation and twisted to create the helical spiral. The Each step back from the master apical file at the
triangular cross-section is more flexible, has more flute constriction area is 0.5 mm shorter than the previous
space and less cross-sectional area than either a one. This combined area is known as the apical control
diamond or square one. zone, recognizing three different diameters in the apical
All K-files function much like wood screws. If you control zone area.
turn a wood screw clockwise, it goes into the wood. If • The first diameter is at 0.5 mm short of the working
you turn the same screw counter-clockwise, it comes length.

16 Fig. 16.13 Balanced force technique (procedure)

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 Cleaning and Shaping of Root Canals 277

Fig. 16.14 Balanced force technique (Steps)

• The next diameter is 1.0 mm coronal to the first one. The routinely used coronal-apical preparation
• The third is 1.5 mm short of the working length techniques are:
(0.5 mm short of the second one). a. Step-down technique
This type of preparation creates an apical stop, which b. Crown-down pressureless technique
facilitates three-dimensional obturation. c. Double flare technique
Conventionally, the apical zone is prepared using d. Rotary techniques
size 20 file to radiographic length; stepback 0.5 mm with
size 25 and size 30 followed by size 35 and size 40 at a. Step-down Technique
1.0 mm back. Finally, prepare with size 45 at 1.5 mm
This is a combination of crown-down/step-back tech-
short (Fig. 16.8).
nique. It is also known as modified step-back technique.
Advantages
• Minimum chances of extrusion of debris beyond the Step wise procedure
apical foramen • The coronal portion of the canal to a depth of
• Less chances of canal transportation 6.0–8.0 mm or at the beginning of the canal curvature
• Provide excellent canal centering ability. is prepared using Gates Glidden drills or appropriate
sized K-files.
Disadvantage
• Use appropriate Gates Glidden drills to refine the
• Sensitive and meticulous technique.
coronal preparation.
B. Coronal-apical Techniques • Determine the working length.
In coronal-apical techniques, the coronal part of the root • Use step-back technique from apical area to merge
canal is prepared first followed by preparation of the with the coronal preparation.
canal moving from coronal end to the apical end. • The canal is recapitulated conventionally.
This technique offers all the advantages of the
Advantages of coronal-apical over apical-coronal coronal-apical preparation and partially overcome the
technique disadvantages of the conventional step-back preparation.
• Allows early débridement of the coronal part of the
canal which may contain the bulk of organic and b. Crown-down Pressureless Technique
microbial debris; thus minimizing the chances of Crown-down pressureless technique was introduced
apical extrusion of the material through the foramen. by Marshall and Pappin with the aim to prepare curved
• Better and deeper penetration of the irrigant aids in canals without causing any deviation. The technique
better cleaning and disinfection of the root canal system mostly utilizes rotary action to prepare the canal; hand
along with decreasing the risk of apical blockage. instruments can also be used.
• Cares for shortening of the working length, which Stepwise procedure
occurs after preparation of the root canals due to the
• Determine radicular access length (the depth to
straightening of the canals in apical-coronal technique.
which no. 35 file penetrates to its point of first
• Better control over apical instrumentation; hence,
reduction in the chances of procedural errors like
transportation, ledging and perforation, etc.
resistance). If it is more than 16 mm, the coronal
portion of the canal should be prepared to this length.
If it is less than 16 mm, a radiograph should be used
16

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 278 Essentials of Endodontics

to determine whether it is because of canal curvature

or any obstruction. If it is due to curvature of the
canal, the canal is prepared to the point of first
resistance; if not the canal is widened with smaller
file until #35 file penetrates to 16 mm depth (Fig. 16.15).
• Establish provisional working length to 3.0 mm short
of the radiographic apex.
• Place #35 file into the canal until it encounters
resistance. At this point give two full revolutions
without apical pressure. Repeat this sequence with
the next smaller file till the provisional working
Fig. 16.16 Crown-down technique (apical preparation)
length is reached.
• Establish a definite working length with the help of
radiograph. Advantages
• Again start preparing with #40 file till the apical • Less periapical extrusion of debris
portion of the canal is prepared to desired diameter • Less apical zip formation
(Fig. 16.16). • Less chances of ledge formation
This technique maintains the canal shape but tends • Straight access to the apical region
to prepare it in a circular fashion. Without the use of • Better penetration of the irrigant.
appropriate irrigants, the canals may not be as clean as
the one prepared using circumferential filing. Disadvantage
• Apical cleanliness is doubtful.
The differences of step-back and crown-down
technique are summarized in Table 16.1.

c. Double Flare Technique

Double flare technique, introduced by Fava, involves
preparing the canal in crown-down manner using K-
files, followed by step-back manner. Conventional
recapitulation along with copious irrigation is
mandatory. This technique is indicated for straight
canals/straight portion of the curved canals and is
Fig. 16.15 Crown-down technique (coronal and middle contraindicated for calcified canals/canals with open
preparation) apices.

Table 16.1 Differences of step-back technique and crown-down technique

Step-back technique Crown-down technique
• Also known as telescopic, serial root canal preparation • Also known as pressureless crown-down, step-down
preparation
• Use hand instruments • Use both hand and rotary instruments
• Small file is used at apex, followed by sequentially increasing • Large file is used at coronal end followed by sequential
the size to the coronal decreasing the size to the apex
• Narrow coronal portion prevents adequate irrigation • Wider coronal preparation allow deeper penetration of
irrigant
• Instrumentation difficult because of narrow coronal preparation • Easy instrumentation
• Less tactile control • Adequate tactile control
• Debris accumulation at apical third area; liable to be • Minimum debris accumulation at apical third area because
pushed out of apex of better irrigation; less debris extrusion
• Obstruction in coronal portion pose difficulties in managing • Apical control zone is managed properly

16 apical control zone

• Not frequently used; clinicians do not prefer • Most frequently used; clinician’s preference

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 Cleaning and Shaping of Root Canals 279

Stepwise procedure Advantages

• Introduce the irrigant into the canal using a small • Effectively remove the canal contents
file in a push and pull motion (without binding). The
• Necrotic root dentin is effectively removed
file is pushed only up to the length estimated from
the preoperative radiograph. • Minimum iatrogenic errors
• Take a new radiograph to redetermine the working • Facilitate compact obturation
length. Double flare technique was modified, whereby after
• The canal is prepared in crown-down manner. preparing the coronal half, balanced force technique
• Introduce a large instrument (size 70 or 80) into the was used to prepare the middle and apical half. The
canal to a depth of about 14 mm or up to the start of preparation was followed by step-back technique to
the canal curvature. Prepare the canal to this length provide double flare in the preparation.
with a filing motion. The preparation techniques are summarized in
• Again introduce the next size smaller instrument Table 16.2.
1.0 mm deeper into the canal and file gently.
• Repeat till the working length is reached and apical d. Rotary techniques
area is prepared. Various rotary instruments (files) of different designs
• The root canal is again prepared in a step-back have been utilized for root canal preparation. The details
manner using recapitulation in between. of rotary instrumentation are described in Chapter 11.

Table 16.2 Summary of the preparation techniques

Technique Key features Advantages Disadvantages
Standardized The file is inserted to the full working Easy to prepare straight canals Not suitable for curved canals
technique length cleaning the canal (ledge formation, zipping, and
perforation in curved canals)
Balanced • Placement of file with a clockwise • Better apical control of file • High incidence of procedural
forced motion, gentle apical advance- • Less amount of extrusion of debris errors such as instrumental
technique ment from canal breakage and canal stripping
• Counterclockwise rotation with • Good centering of instrument in • Time consuming
gentle apical pressure the canal
• Clockwise rotation with coronal
movement of file
Step-back Apical preparation is carried out with • Greater flare facilitate dense • May lead to apical blockage
technique smaller files and sequentially the canal obturation (debris collected below the
is prepared with increase in file size • Less chances of trauma to peri- apical constriction area)
apical tissues • Alteration of working length
• Allows effective removal of debris • Tendency for canal deviation
• Apical matrix at apical area when using the larger inflexible
minimizes chances of over instruments (Hour-glass
instrumentation and subsequently preparation)
overfiling • The H-file may cause over-
flaring or strip-perforation
Crown-down The coronal portion of the canal is • Less periapical extrusion of debris Apical cleanliness is doubtful
technique prepared first followed by the apical • Less apical zip formation
portion prepared with smaller files • Less chances of ledge formation
• Straight access to the apical region
• Better penetration of the irrigant
Double flare Involves preparing the canal in • Effectively remove the canal Not suitable in canals with open
technique crown-down manner using K-files, contents apices
followed by step-back manner • Necrotic root dentin is effectively

16
removed
• Minimum iatrogenic errors
• Facilitate compact obturation

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 280 Essentials of Endodontics

BIBLIOGRAPHY 22. Kim HC, Sung SY, Ha JH, Solomonov M, Lee JM, Lee CJ and
Kim BM. Stress generation during self-adjusting file
1. Abou-Rass M, Frank A and Glick D. The anticurvature filling movement: minimally invasive instrumentation. J. Endod.:
method to prepare the curved root canal. J. Am. Dent. Assoc.: 2013; 39:1572–1575.
1980; 101:792–794.
23. Kyomen SM, Caputo AA and White SN. Critical analysis of
2. Ahmad M, Pittford T and Crum L. Ultrasonic debridement of the balanced force technique in endodontics. J. Endod.: 1994;
root canals: an insight into the mechanisms involved. J. 20:332–337.
Endod.: 1987; 13:93–101.
24. Lambrianidis T. Ledging and blockage of root canals during
3. Ansari I and Maria R. Managing curved canal. Contemp. Clin.
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Dent.: 2012; 3:237–241.
management and outcomes. Endod. Topics: 2006; 15:56–74.
4. Baugh D and Wallace J. The role of apical instrumentation
25. Lopez FU, Travessas JAC, Fachin E, Fontanella V and Grecca
in root canal treatment: a review of the literature. J. Endod.:
F. Apical transportation: two assessment methods. Aust.
2005; 31:333–340.
Endod. J.: 2009; 35:85–88.
5. Buchanan LS. The predefined preparation comes of age.
26. Micket AK. The role of apical size determination and
Endod. Pract.: 2001; 4:6–18.
enlargement in reduction of intracanal bacteria. J. Endod.:
6. Buchanan LS. The standardized-taper root canal preparation.
2007; 33:21–23.
Part 1: concepts for variably tapered shaping instruments.
Int. Endod. J.: 2000; 33:516–529. 27. Morgan LF and Montgomery S. An evaluation of the crown-
down pressureless technique. J. Endod.: 1984; 10:491–498.
7. Buchanan LS. The standardized-taper root canal preparation.
Part 2: GT file selection and safe handpiece driven file use. 28. Mounce RE. New possibilities for managing severe curvature:
Int. Endod. J.: 2001; 34:63–71. the twisted file. Endod. Turbine: 2008; 9–12.
8. Burklein S and Schafer E. Critical evaluation of root canal 29. Olson DG, Roberts S, Joyce AP, Collins DE and McPherson
transportation by instrumentation. Endod. Topics: 2013; JC. Unevenness of the apical constriction in human maxillary
29:110–124. central incisors. J. Endod.: 2008; 34:157–159.
9. Carrotte P. Endodontics: Part 7. Preparing the root canal. Br. 30. Peters OA, Bahia MG and Pereira ESJ. Contemporary root
Dent. J.: 2004; 197:603–613. canal preparation: Innovation in biomechanics. Dent. Clinic.
10. Cassim I and Van der Vyver PJ. The importance of glide path N. Am.: 2017; 61:37–58.
preparation in endodontics: a consideration of instruments 31. Peters OA. Current challenges and concepts in the preparation
and literature. SADJ: 2013; 68:322, 324–327. of root canal systems: a review. J. Endod.: 2004; 30:559–567.
11. Charles TJ and Charles JE. The 'balanced force' concept for 32. Plotino G, Ahmed HM and Grande NM. Current assessment
instrumentation of curved canals revisited. Int. Endod. J.: of reciprocation in endodontic preparation: a comprehensive
1998; 31:166–172. review-part II: properties and effectiveness. J. Endod.: 2015;
12. Dummer PM, McGinn JH and Rees DG. The position and 41:1939–1950.
topography of the apical root canal constriction and apical 33. Plotino G, Pameijer CH, Grande NM and Somma F.
foramen. Int. Endod. J.: 1984; 17:192–198. Ultrasonics in endodontics: a review of literature. J. Endod.:
13. Fava LR. The double flared technique: an alternative for 2007; 33:81–95.
biomechanical preparation. J. Endod.: 1983; 9:76–80. 34. Roane JB, Sabala CL and Duncanson MG. The ‘balanced
14. Habib AA, Taha MI and Farah EM. Methologies used in quality force’ concept for instrumentation of curved canals. J. Endod.:
assessment of root canal preparation techniques: Review of 1987; 13:93–101.
the literature. J. Taibah Univ. Med. Sci.: 2015; 10:123–131. 35. Ruddle CJ. Current concepts for preparing the root canal
15. Hulsman M, Peters OA and Dummer PMH. Mechanical system. Dent. Today: 2001; 1–9.
preparation of root canals: Shaping of goals, techniques and 36. Ruddle CJ. Endodontic canal preparation: new innovations
means. Endod. Topic: 2005; 10:30–76. in glide path management and shaping canals. Dentistry:
16. Hung-Hong H, Sang WK, Sung-Kyo K and Hyeon-Cheol K. 2014; 33:1–7.
Screw-in forces during instrumentation by various file systems. 37. Sakkir N, Thaha KA, Nair MG, Joseph S and Christlin R.
Restor. Dent. Endod.: 2016; 41:304–309. Management of dilacerated and S-shaped root canals – An
17. Ja JH, Cheung GS, Vrsluis S, Lee CJ, Kwak SW, and Kim HC. endodontic challenge. J. Clin. Diagn. Res. 2014;8: ZD22–24.
“Screw-in” tendency of rotary nickel-titanium files due to 38. Simon JHS. The apex: how critical is it? Gen. Dent.: 1994;
design geometry. Int. Endod. J.: 2015; 48:666–672. 42:330–334.
18. Jafarzadeh H and Abbott PV. Dilaceration: review of an 39. Usman W, Baumgartner JC and Marshall JG. Influence of
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19. Jafarzadeh H and Abbott PV. Ledge formation: Review of a great 30:110–112.
challenge in endodontics. J. Endod.: 2007; 33:1155–1162. 40. West JD. The endodontic glidepath: “secret to rotary safety”.
20. Juric IB and Anic I. The use of lasers in disinfection and Dent. Today: 2010; 29:86, 88, 90–93.
cleaning of root canals: a review. Acta. Stomatol. Croat.: 41. Wu MK, Barkis D, Roris A and Wasselink PR. Does the first
2014; 48:6–15. file to bind correspond to the diameter of the canal in apical
21. Kesler G, Gal R, Kesler A and Koren R. Histological and region? Int. Endod J.: 2002; 35:264–267.

16 scanning electron microscope examination of root canal after

preparation with Er: YAG laser microprobe: a preliminary in
vitro study. J. Clin. Laser Med. Surg.: 2002; 20:269–277.
42. Wu MK, Wesselink PR and Walton RE. Apical terminus
location of root canal treatment procedures. O. Surg., O.
Med., O. Path. 2000, 89, 99–103.

t.me/Dr_Mouayyad_AlbtousH
Chapter
17
Endodontic Smear Layer

Successful endodontic treatment depends upon

thorough cleaning, shaping, disinfecting and obturation
of root canals so as to achieve three-dimensional
hermetic sealing of the pulp spaces. During mechanical
preparation or whenever dentin is cut using hand or
rotary instruments, the mineralized tissues are scattered
producing considerable amount of debris. The debris
so produced in the form of small particles of collagen
matrix (composed of organic and inorganic material)
is spread as an amorphous, irregular layer over dentinal
surface, is known as ‘smear layer’. This layer primarily
contains ground dentin, remnants of pulp tissue,
odontoblastic processes and bacteria.
American Association of Endodontists defined smear
layer as ‘a surface film of debris retained on dentin or other a
surfaces after instrumentation with either rotary instruments
or endodontic files; consists of dentin particles, remnants of
vital or necrotic pulp tissue, bacterial components and
retained irrigants’. A few authors have described smear
layer as ‘organic matter trapped in translocated
inorganic dentin’. McComb and Smith (1975) were the
first researchers who described the presence of smear
layer on surfaces of instrumented root canals in their
Scanning Electron Microscopic study (Fig. 17.1a and b).
b
The smear layer formed in cavities (coronal) and in the
Fig. 17.1 (a) Scanning electron microscope; (b) Heavy
root canals is different. The instrumentation tools and
smear layer
procedures are different in coronal cavities; the dentinal
tubules in root dentin show great variation and also superficial smear layer is estimated to be 1.0–2.5 μm in
the root canal contains pulp remnants and bacteria thickness; whereas, the smear layer contents may get
(odontoblastic processes, remnants of pulp tissue and packed into the dentinal tubules to a depth of 40 μm.
bacteria present in root canal smear layer). The penetration of smear layer components into
The thickness of smear layer depends on the type dentinal tubules could be caused by capillary action as
and sharpness of cutting instrument and also whether a result of adhesive forces between the dentinal tubules
the cutting was carried out on dry or wet dentin. and the smear contents, known as ‘smear plugs’.
The smear layer contents are described in two It has been established that the amount of smear layer
parts; the superficial smear layer and the smear layer produced during rotary instrumentation is far greater
where contents are packed into dentinal tubules. The as compared to hand filing.

281

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 282 Essentials of Endodontics

FACTORS INFLUENCING FORMATION OF SMEAR LAYER

The complexity of root canal system usually limits the
efficacy of thorough cleaning the pulp spaces. The
deviated root canal anatomy may pose difficulties in
instrumentation, subsequently leading to unevenly
prepared zones on root canal walls. These uneven zones
may contribute to produce more of smear layer.
During instrumentation of root canal, dentin is cut
by rotational and filing movements. Efficacy of cutting
is dependent upon working dynamics, applied force,
shape and size of the blade, instrument’s axis configura-
tion, etc. When dentinal chips are accumulated in flutes
of the instrument, working effect is impaired and friction a
between instrument and canal walls is increased. The
cutting effect is decreased, consequently larger amount
of smear layer is formed (Fig. 17.2a and b).
A few studies have confirmed that manual instru-
mentation produced less smear layer as compared to
the use of rotary instruments. Rotary preparation of
root canal provide more effective instrumentation; how-
ever, higher speed may compact smear layer on the
canal surface and into the dentinal tubules (Fig. 17.3a
and b). It is established that sonic and ultrasonic
preparation of root canal are the most efficient methods
leading to only minor formation of smear layer. Massive

Fig. 17.3 (a) Smear layer after hand filing; (b) Smear layer
after rotary instrumentation

irrigation directed towards working part on the

instrument facilitates removal of dentin and prevents
debris binding on the root canal walls. Preparation of
root canal without irrigation causes up to 70% more
stagnation of smear layer.
a It is demonstrated that significant stagnation of
smear layer was observed following irrigation with
standard needle; whereas,vent needle enable detaching
of smear layer from root canal walls under pressure,
thus making débridement more efficient. Most of
irrigation solutions have physical (removal of smear
layer) and chemical (dilute and demineralize) properties,
subsequently enhancing permeability of radicular dentin.
The non-instrumentation technique of canal
preparation may prepare the canal without producing
smear layer. A hydrodynamic technique with sonically
driven polymer instruments can disrupt the smear
layer, the process known as ‘hydrodynamic disinfection’.

MANAGEMENT OF SMEAR LAYER

17
b

Fig. 17.2 (a) Smear layer in apical third area; (b) Generalized The management of smear layer in endodontics has
smear layer after instrumentation always been controversial. Various investigators are of

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 Endodontic Smear Layer 283

the view that maintaining the smear layer may block Features warrant the retention of smear layer are:
the dentinal tubules and limit bacterial or toxin • Smear layer block the dentinal tubules, preventing
penetration by altering dentinal permeability. Another the exchange of bacteria and other irritants by
school of belief is that the smear layer, being a loosely altering their permeability.
adherent structure, should be completely removed from • It serves as a barrier to prevent bacterial migration
the surface of root canal walls because it can harbor into dentinal tubules.
bacteria and provide an avenue for leakage. Further, it • A few authors have observed that bacteria remaining
may also limit the effective disinfection of dentinal after root canal preparation were sealed into dentinal
tubules by preventing intracanal medicaments from tubules by smear layer and subsequent filling
penetrating the dentinal tubules. Earlier studies have materials.
observed that the smear layer was not a complete
barrier and could only delay bacterial penetration. Removal of the Smear Layer
Majority of investigators favor removal of smear It is established that the smear layer may be infected
layer. The smear layer is non-homogenous and easily and also protect the bacteria already present in the
get dislodged from the underlying tubules. It slowly dentinal tubules. It is wiser to remove the initially
disintegrates and dissolves leaving a void between created smear layer in infected root canals and to allow
canal wall and the sealer. penetration of intracanal medicaments into the dentinal
It has been established that removing the smear layer tubules. The smear layer can be removed using
enhanced the adaptation of gutta-percha in both cold mechanical, chemical, ultrasonic and by means of laser.
and heat compacted obturation without a sealer. It is
also confirmed that removal of smear layer improved a. Mechanical Removal
the fluid-tight seal of the root canals; whereas, even The smear layer removal has been tried using
modified obturating techniques might not be able to mechanical means. The mechanical removal of smear
achieve effective results. layer includes:
A few authors have observed that removal of smear
layer did not prevent bacterial penetration along the i. Microbrush (canal brush): A microbrush (canal
root canal fillings. brush), has been specifically fabricated for root canal
Should the smear layer be removed or retained has cleaning. The brush is available in three sizes, small,
always been a matter of concern amongst the medium and large, corresponding to apical diameter
investigators. of 25, 30 and 40 respectively. The brush is used along
with the irrigating solution, being revolved at a slow
Features warrant the removal of smear layer are: speed. However, it did not provide any added advan-
• Unpredictable thickness and volume. tage as regard removal of smear layer. The appropriate
• Mainly contains bacteria, their by-products and size of the brush is the main parameter, which is
necrotic tissue. difficult to coincide with the canal configuration.
• Act as a substrate for bacteria and may allow bacteria Studies have confirmed that smear layer removal would
penetrating deeper in the dentinal tubules. be because of the ‘irrigant’ used in the root canal, rather
• May limit the penetration of disinfecting agents into than the action of brush. However, various investigators
the dentinal tubules. Bacteria present deep within have confirmed that the use of flexible microbrushes
dentinal tubules may not be disinfected because of can reduce debris and remove smear layer from the root
smear layer. It is established that following the canal walls.
removal of the smear layer, bacteria in dentinal ii. XP-endo finisher: It is established that rotary Ni-Ti
tubules can easily be destroyed. files during instrumentation come into contact with
• Act as a barrier between filling materials and the only 40–50% of the canal walls; therefore, large portion
canal wall, compromising achieving the hermetic of the root canal wall remain untreated. XP-endo
seal. The sealers can penetrate dentinal tubules only finisher is a modified Ni-Ti file without taper and of
if the smear layer is removed. It is documented that small diameter (25/.00). Due to its specific design, it
coronal leakage of root canal fillings was less in can reach the inaccessible areas of the canal wall and
smear-free cases than those with smear layer. efficiently remove the smear layer. The file has added
• Being loosely adherent structure, it is a potential
avenue for leakage between root canal obturated
material and the dentinal walls.
advantage of changing the shape during rotation in the
root canal, which effectively remove dentin debris and
smear layer.
17

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 284 Essentials of Endodontics

b. Chemical Removal
A number of chemicals used as irrigants have been tried
to remove the smear layer. Various irrigating solutions
have the potential to remove the debris and smear layer
created by the instrumentation process. The solution
commonly used to remove smear layer are:
i. Sodium hypochlorite/chlorhexidine: Sodium hypo-
chlorite is known for its potential to dissolve organic
tissues; however, it cannot effectively remove smear
a
layer from the instrumented root canal walls. The
combination of sodium hypochlorite and hydrogen
peroxide was also ineffective; however, alternating use
of sodium hypochlorite with EDTA was effective in
smear layer removal. Chlorhexidine, has antibacterial
effect, but not dissolve organic debris and is also
ineffective in smear layer removal.
ii. Ethylenediaminetetra-acetic acid (EDTA): The most
common chelating solutions are EDTA based, which
reacts with calcium ions in the dentin and forms soluble b
calcium chelates. EDTA can decalcify dentin to a depth
of 20–30 μ in five minutes (Fig. 17.4a to d). The timings
of EDTA application is important, otherwise EDTA
remains ineffective, especially in apical third area of
root canals. The alternate use of 17% EDTA and 5.25%
sodium hypochlorite removes smear layer completely
from coronal and middle thirds; however, less effective
in apical third areas (EDTA removes the inorganic
component and sodium hypochlorite removes the
organic part). As regard smear layer removal, ethylene-
glycol tetra-acetic acid (EGTA) was comparable to c
EDTA.
A quaternary ammonium bromide (cetavlon) has
been added to EDTA solutions to reduce surface tension
and increase penetrability of the solution; the solution
is called EDTAC. EDTA and cetavlon (EDTAC) solution
has been effective in removing smear layer (to be kept
in root canals for 15 minutes for effective results).
However, chelating/penetrating effect remained
negligible in apical third area. It has been established
that paste-type chelating agents, having lubricating
effect, do not remove smear layer effectively as
compared to liquid EDTA.
A combination of bis-dequalinium-acetate and EDTA
(Solvidont) has shown effective potential to remove the
smear layer, even in the apical third area.
iii. Tetracyclines: Tetracyclines including doxycycline d
and minocycline are effective against a wide range of
Fig. 17.4 (a) Absence of smear layer in coronal third after
microorganisms. They have low pH in concentrated using EDTA; (b) Absence of smear layer in middle third

17 solution and act as a calcium chelator; may cause root

surface demineralization. They are effective in removing
smear layer from the surface of instrumented canals
after using EDTA; (c) Presence of smear layer in apical
third after using EDTA; (d) Erosion of peritubular and
intertubular dentin caused by EDTA

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 Endodontic Smear Layer 285

and root-end cavity preparations. It is speculated that

a reservoir of active antibacterial solution might remain
sticking to root canal walls because doxycycline readily
attaches to root dentin and is released subsequently.
iv. MTAD: MTAD, an irrigating solution, containing
mixture of tetracyclines, a detergent and an acid (3.0%
doxycycline hyclate, 4.25% citric acid and 0.5% poly-
sorbate detergent) was developed having potential of
removing smear layer and also disinfecting the root canals. a
Various studies have observed that MTAD demineralized
dentin faster than 17% EDTA (Fig. 17.5a to c).
v. QMix: QMix 2 in 1 is a new irrigation solution that
facilitates smear layer removal and also provides
disinfection. The solution contains a mixture of
bisguanide (antimicrobial agent), polyaminocarboxylic

a
c

Fig. 17.6 (a) Absence of smear layer in coronal third after

using QMix; (b) Absence of smear layer in middle third
after using QMix; (c) Presence of smear layer in apical
third after using QMix

acid (a calcium chelating agent) and a surfactant. The

use of QMix 2 in 1 saves time as compared to sequential
use of 17% EDTA and 2.0% chlorhexidine. The solution
b
provides fair activity against bacteria and also an effec-
tive irrigation in 60 to 90 seconds. The manufacturers
advocate its use as the final rinse before obturation.
Various studies have confirmed the superior effect of
QMix as compared to 17% EDTA (Fig. 17.6a to c).
A few authors observed that the smear layer removal
and antimicrobial effects of QMix was comparable to
EDTA. QMix is considered effective against Enterococcus
faecalis (QMix has low surface tension; wettability of
dentin is effectively achieved with QMix).
c vi. Organic acids: The effectiveness of mild acids as a
Fig. 17.5 (a) Absence of smear layer in coronal third after
root canal irrigant has been demonstrated. Citric acid,
using MTAD; (b) Absence of smear layer in middle third
after using MTAD; (c) Presence of smear layer in apical
third after using MTAD
polyacrylic acid, lactic acid and phosphoric acid are
being used to remove smear layer. Citric acid is consi-
dered better than the other acids used (Fig. 17.7a and b).
17

t.me/Dr_Mouayyad_AlbtousH
 286 Essentials of Endodontics

Fig. 17.8 Partial removal of smear layer in the apical third

of the root canal by tannic acid

It effectively removes the smear layer when used as

root canal irrigant. Various studies have observed that
the efficacy of super-oxidised water was comparable
to 17% EDTA, with significantly less erosion of dentinal
surface.
viii. Chitosan: Chitosan, a natural polysaccharide, has
broad-spectrum of antimicrobial properties and also
has chelating characteristics. It shows excellent
b biocompatibility, high bioactivity, biodegradability,
absorption capacity and low toxicity. Chitosan
Fig. 17.7 (a) Root canal dentin treated with citric acid compounds (chitosan nitrate and chitosan acetate)
demonstrating open dentinal tubules; (b) Precipitate of alone and in combination with chlorhexidine have
citric acid formed on the root canal dentin
effectively removed smear layer from the root canal
Sequential use of 10% citric acid and 2.5% sodium hypo- walls. 0.6% chitosan has also been used as dentin
chlorite solution is considered as a better combination. conditioning agent, producing smooth, wide open
A few authors have observed that citric acid-sodium dentinal tubules.
hypochlorite combination was not as effective as citric Various studies have confirmed the use of 0.2 to 0.6%
acid-EDTA combination. It is emphasized that the chitosan when irrigated for three minutes, adequately
quality of smear layer removal is related to pH and time removed the smear layer. It has also been reported that
of exposure of the acids. it caused less erosion of dentin as compared to EDTA.
Five to ten percent polyacrylic acid as an irrigant is A few studies showed that chitosan and their
effective in removing smear layer in accessible regions. derivatives interacted with metalloproteinase matrix,
40% polyacrylic acid has been reported to be very improving the resistance of dentin to degradation.
effective; however, it is advised to use it for 30 seconds ix. Smear clear: A recently introduced chelating agent,
only. 50% lactic acid was less effective than 50% citric smear clear contains 17% EDTA and two surfactants
acid for removal of smear layer (attributed to viscosity (polyoxyethylene and isobutyl cyclohexyl phthalate
of lactic acid). 25% tannic acid has also been used ether).
successfully in eradicating smear layer (Fig. 17.8).
A few studies comparing efficacy of smear clear and
vii. Super-oxide water (oxum): Super-oxide water is a 17% EDTA in removing smear layer have observed
powerful antimicrobial agent against bacteria, fungi similar performance in smear layer removal from
and viruses. It is rich in reactive oxygen and has neutral coronal and middle third of the root canals; however,
pH. Super-oxidized water, commercially available as in apical third, smear clear showed significantly better

17 oxum, is stable and has longer shelf-life. The free

radicals (oxygen anion) of this solution rapidly damage
the cell wall protein of the microorganisms.
results as compared to 17% EDTA. Smear clear has low
surface tension and improved dentin-wettability,
facilitating easy flow into narrow canals. This property

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 Endodontic Smear Layer 287

depends on many factors; viz. wavelength of laser, the

duration of exposure and absorption in the tissue, the
geometry of root canal and the conductors. Almost all
types of lasers effectively remove the smear layer.
The most commonly used laser in endodontics is
Neodium: Yttrium-Aluminium-Garnet (Nd:YAG)
having wavelength of 1064 nm. The wavelength, being
in the near-infrared range, the flexible conductor can
effectively be used in narrow and curved canals,
providing bactericidal effect and removing the smear
layer.
Erbium-Yttrium-Aluminium-Garnet (Er:YAG)
having wavelength of 2940 nm is used for cleaning and
shaping of root canals. When applied in the canal, the
Fig. 17.9 Root canal dentin treated with smear clear water of the hard tissue inside evaporates and ablates
demonstrating clean open dentinal tubules devoid of the surrounding tissues. The increase in temperature
smear layer and debris on the root surface is within the acceptable limits.
Various studies have observed that the removal of
might be the probable reason for better removal of
smear layer with Er:YAG laser is greater as compared
smear layer from the apical third area of root canals
to removal with Nd:YAG laser (energy of Er:YAG laser
(Fig. 17.9).
is absorbed by water, the water evaporates and ablates
As regards timings, most of the irrigants are effective the molecules of dentinal surface; whereas, Nd:YAG
only at longer duration time (5.25% sodium hypo-
laser is poorly absorbed by water and is absorbed by
chlorite and 17% EDTA need minimum of 3–5 minute proteins of the tissues).
to be effective); whereas, smear clear is effective in one
The main difficulty with laser removal is access to
minute application. Ankur Dua et al (2015) in their SEM
narrow canals (root canal intricacies) with the
study, evaluating the effect of duration of application
availability of relatively large probes for delivery of
of smear clear in removing intracanal smear layer,
laser beam. A few authors have also observed destruc-
observed that final irrigation with smear clear or 17%
tion of peritubular dentin along with removal of smear
EDTA followed by 1.0% sodium hypochlorite were
layer.
effective in removing smear layer for all duration of
applications (one minute, 3 minutes and 5 minutes). The main difficulty with laser is the access to small
root canal areas. Laser probe is relatively large;
c. Ultrasonic however, flexible conductors are now available with a
Sodium hypochlorite activated by the ultrasonic delivery tip of 300 μm for inaccessible areas.
system when used as an irrigant provided smear-free
root canal surfaces. Varying concentration of sodium BIBLIOGRAPHY
hypochlorite (1.0–5.0%) when used with ultrasonic
energy, has been effective in removing smear layer. 1. Amaral P, Forner L and Llena C. Smear layer removal in canals
shaped with reciprocating rotary systems. J. Clin. Exp. Dent.:
Studies comparing the effect of different ultrasonic
2013; 5:227–230.
irrigation periods on removing smear layer, observed
2. Andrabi SM, Kumar A, Mishra SK, Tewari RK, Alam S and
that smear layer removal was effective in 3–5 minute
Siddiqui S. Effect of manual dynamic activation on smear
timings, whereas, one minute was ineffective. A few layer removal efficacy of ethylene diamine tetra-acetic acid
authors have even reported no effect of ultrasonics on and smear clear: an in vitro scanning electron microscopic
smear layer removal (ultrasonically energized sodium study. Aust. Endod. J.: 2013; 39:131–136.
hypochlorite, even at full concentration was ineffective 3. Calt S and Serper A. Smear layer removal by EGTA. J. Endod.:
in smear layer removal). It is advised to use EDTA/ 2000; 26:459–461.
EDTAC with sodium hypochlorite using ultrasonic 4. Cameron JA. The use of ultrasound for the removal of the
streaming to achieve desired results. smear layer. The effect of sodium hypochlorite concentration:
SEM study. Aust. Dent. J.: 1988; 33:193–200.
d. Lasers
Lasers are being used to vaporize necrotic tissues and
debris in the root canals. The effectiveness of laser
5. Card SJ, Sigurdsson S, Orstavik D and Trope M. The
effectiveness of increased apical enlargement in reducing
intracanal bacteria. J. Endod.: 2002; 28:779–783.
17

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 288 Essentials of Endodontics

6. Caron G, Nham K, Bronnec F and Machtou P. Effectiveness 20. Khedmat S and Shokouhinejad N. Comparison of the efficacy
of different final irrigant activation protocols on smear layer of three chelating agents in smear layer removal. J. Endod.:
removal in curved canals. J. Endod.: 2010; 36:1361–1366. 2008; 34:599–602.
7. da Silva LA, Sanguino AC, Rocha CT, Leonardo MR and Silva 21. Lui JN, Kuah HG and Chen NN. Effect of EDTA with and
RA. Scanning electron microscopic preliminary study of the without surfactants or ultrasonics on removal of smear layer.
efficacy of smear clear and EDTA for smear layer removal J. Endod.: 2007; 33:472–475.
after root canal instrumentation in permanent teeth. J. Endod.: 22. Mancini M, Armellin E, Casaglia A, Cerroni L and Cianconi L.
2008; 34:1541–1544. A comparative study of smear layer removal and erosion in
8. Dechichi P and Moura CCG. Smear layer: a brief review of apical intraradicular dentine with three irrigating solutions:
general concepts. Part I. Characteristics, compounds, a scanning electron microscopy evaluation. J. Endod.: 2009;
structure, bacteria and sealing. RFO UPF: 2006; 11:96–99. 35:900–903.
9. De-Deus G, Reis C, Fiedel S, Fiedel R and Paciornik S. Dentin 23. Mandorah A. Effect of irrigating needle depth in smear layer
demineralization when subjected to BioPure MTAD: a removal: Scanning electron microscope study. Saudi Endod.
longitudinal and quantitative assessment. J. Endod.: 2007; J.: 2013; 3:114–119.
33:1364–1368. 24. Mello I, Coil J and Antoniazzi JH. Does a final rinse to remove
smear layer interfere on dentin permeability of root canals?
10. Del Carpio-Perochena A, Bramante C, Duarte M, de Moura
Oral Surg., Oral Med., Oral Pathol., Oral Radiol. Endod.:
M, Aouada F and Kishen A. Chelating and antibacterial
2009; 107:e47–51.
properties of chitosan nanoparticles on dentin. Restor. Dent.
Endod.: 2015; 40:195–201. 25. O’Connell M, Morgan L, Beeler W and Baumgartner C. A
comparative study of smear layer removal using different salts
11. Divito E, Peters OA and Olivi G. Effectiveness of the Erbium:
of EDTA. J. Endod.: 2000; 26:739–743.
YAG laser and new design radial and stripped tips in removing
the smear layer after root canal instrumentation. Lasers Med. 26. Perez-Heredia M, Ferrer-Luque CM, Gonzalez-Rodriguez MP,
Sci.: 2012; 27:273–280. Martin-Peinado FJ and Gonzalez-Lopez S. Decalcifying effect
of 15% EDTA, 15% citric acid, 5% phosphoric acid and 2.5%
12. Dotto SR, Travassos RM, de Oliveira MP, de Lima Machado sodium hypochlorite on root canal dentin. Int. Endod. J.: 2008;
E and Martins L. Evaluation of ethylendiaminetetraacetic acid 41:418–423.
(EDTA) solution and gel for smear layer removal. Aust. Endod.
J.: 2007; 33:1–4. 27. Periera RS, Miranda PF, Pereira GS, Barroso JM, Bortolotti
MGL and Junqueira JLC. Effectiveness of 17% EDTA in the
13. Dua A, Dua D and Uppin VM. Evaluation of the effect of removal of smear layer and calcium hydroxide dressing
duration of application of smear clear in removing intracanal from the root canal walls. Rev. Gaucha Odontol.: 2013;
smear layer: SEM study. Saudi Endod. J.: 2015; 5:26–32. 61:313–317.
14. Eliot C, Hatton JF, Stewart GP, Hildebolt CF, Jane GM and 28. Pimento J, Zaparolli D, Pecora J and Cruz-Filho A. Chitosan:
Gutmann JL. The effect of the irrigantQMix on removal of effect of a new chelating agent on the microhardness of root
canal wall smear layer: An ex vivo study. Odontology: 2014; dentin. Braz. Dent. J.: 2012; 23:212–217.
102:232–240. 29. Protogerou E, Arvaniti I, Vlachos I and Khabbaz MG.
15. Fachin EVF, Scarparo RK and Massoni LIS. Influence of smear Effectiveness of a canal brush on removing smear layer: a
layer removal on the obturation of root canal ramifications. scanning electron microscopy study. Braz. Dent. J.: 2013;
J. Appl. Oral Sci.: 2009; 17:240–243. 24:580–584.
16. Garip Y, Sazak H and Hatipoglu GM. Evaluation of smear 30. Rathakrishnan M, Sukumaran VG and Subbiya A. To evaluate
layer removal after use of a canal brush: an SEM study. Oral the efficacy of an innovative irrigant on smear layer removal
Surg., Oral Med., Oral Pathol., Oral Radiol. Endod.: 2010; – SEM analysis. J. Clin. Diagn. Res.: 2016; 10:104–106.
110:62–66. 31. Reza B, Mohsen HS, Elham F, Mina N and Sara N. Evaluation
17. Gusiyska A, Dyulgerova E, Vassileva R and Gyulbenkiyan E. of root canal smear layer removal by two types of lasers: A
The effectiveness of a Chitosna-Citrate solution to remove scanning electron microscopy study. Eur. J. Gen. Dent.: 2013;
the smear layer in root canal treatment—an in vitro study. 2:151–157.
Int. J. Sci. Resch.: 2016; 5:1169–1174. 32. Schoop U, Moritz A, Kluger W, Patruta S, Goharkhay K and
18. Kamel WH and Kataia EM. Comparison of the efficacy of Sperr W. The Er:YAG laser in endodontics: Results of an
smear clear with and without a canal brush in smear layer in vitro study. Lasers Surg. Med.: 2002; 30:360–364.
and debris removal from instrumented root canal using 33. Silva P, Guedes D, Nakadi F, Pecora J and Cruz-Filho A.
WaveOne versus Pro Taper: a scanning electron microscopic Chitosan: a new solution for removal of smear layer after
study. J. Endod.: 2014; 40:446–450. root canal instrumentation. Int. Endod.: 2013; 46:332–338.
19. Keles A, Kamalak A, Keskin C, Akcay M and Uzun I. The 34. Spano JC, Silva RG, Guedes DF, Sousa-Neto MD, Estrela C
efficacy of laser, ultrasound and self-adjustable file in and Pecora JD. Atomic absorption spectrometry and scanning

17 removing smear layer debris from oval root canals following

retreatment: a scanning electron microscopy study. Aust.
Endod. J.: 2016; 1–8.
electron microscopy evaluation of calcium ions and smear
layer removal with root canal chelators. J. Endod.: 2009;
35:727–730.

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 Endodontic Smear Layer 289

35. Stojicic S, Shen Y, Qian W, Johnson B and Haapasalo M. 40. Vemuri S, Kolanu SK, Varri S, Pabbati RK, Penumaka R and
Antibacterial and smear layer removal ability of a novel Bolla N. Effect of different final irrigating solutions on smear
irrigant, QMix. Int. Endod. J.: 2012; 45:363–371. layer removal in apical third of root canal: A scanning electron
36. Timpawat S, Vongsavan N and Messer HH. Effect of removal microscope study. J. Conserv. Dent.: 2016; 19:87–90.
of the smear layer on apical microleakage. J. Endod.: 2001; 41. Violich DR and Chandler NP. The smear layer in endodontics
27:351–353. – a review. Int. Endod. J.: 2010; 43:2–15.
37. Torabinejad M, Handysides R, Khademi AA and Bakland LK. 42. Vlad R, Kovacs M, Sita D and Pop M. Comparison between
Clinical implications of the smear layer in endodontics: a different endodontic irrigating protocols in smear layer
review. Oral Surg., Oral Med., Oral Pathol., Oral Radiol. removal from radicular dentin. Eur. Sci. J.: 2016; 12:38–43.
Endod.: 2002; 94:658–666. 43. Zargar N, Dianat O, Asnaashan M, Ganjali M and Zadsirjan S.
38. Torbabinejad M, Khademi AA and Babgoli J. A new solution The effect of smear layer on antimicrobial efficacy of three
for the removal of smear layer. J. Endod.: 2003; 29:170–175. root canal irrigants. Iran. Endod. J.: 2015; 10:179–183.
39. Uroz-Torres D, Gonzalez-Rodriguez MP and Ferrer-Luque 44. Zivkovic S, Neskovic J, Jovanovic-Medojevic M, Popovic-
CM. Effectiveness of the EndoActivator System in removing Bajic M and Zivkovic-Sandic M. XP-Endo Finisher: A new
the smear layer after root canal instrumentation. J. Endod.: solution for smear layer removal. Serbian Dent. J.: 2015;
2010; 36:308–311. 62:122–126.

17

t.me/Dr_Mouayyad_AlbtousH
Chapter
18
Root Canal Irrigants
and Medicaments

Microorganisms and their toxic products are the main • Lubrication of canal walls and instruments.
etiological factors in pulpal and periapical pathology. • Removal of dentin debris and smear layer produced
The main aim of endodontic treatment is the elimination by instrumentation, by physical flushing action.
of bacteria and their by-products from the infected root
canal. Instrumentation and irrigation are important Requisites for an Ideal Irrigant
procedures involved in the physical removal of micro- Based on the objectives, the ideal irrigant should have
organisms from the root canal system, subsequently the following requisites:
controlling endodontic infection. Irrigation is defined
• Should be non-toxic and non-carcinogenic to tissues
as ‘to wash out body cavity or wound with saline or medicated
(should not induce cell-mediated immune response)
solutions’.
• Broad antimicrobial spectrum and high efficacy
The morphology of pulp cavity is of the most complex against anaerobic and facultative microorganisms
nature. It is unrealistic to assume that a linear streamlined organized in necrotic pulp spaces
instrument can reach out into the delicate intricacies of
• Tissue dissolving ability; should dissolve remaining
the pulp spaces to effectively débride its contents. The
pulp/organic tissues
effective use of an irrigant can clean areas of the webs,
deltas, fins and anastomoses in the root canal. • Biocompatible
• Low surface tension (better wetting potential)
Irrigants are used during root canal preparation to
help lubricate canal walls, soften dentin, remove debris • Low neutralizability (should not get nullified by
and smear layer, dissolve organic matter, flush out canal components)
microorganisms and their by-products, and clean areas • Non-irritating to periapical tissues (should not
inaccessible to endodontic instruments. interfere with periapical healing)
Over the years, a variety of solutions have been used • Able to remove the smear layer
during root canal treatment. These include hot water, • Should not affect the sealing ability of obturating
coconut water, physiologic saline, local anesthetic materials
solution, urea and urea peroxide in glycerine, hydrogen • Should not damage the root canal dentin
peroxide, chlorhexidine sodium hypochlorite, ethylene- • Easy availability
diaminetetra-acetic acid (EDTA), BioPure/MTAD and • Cost-effective
various plant extracts. Recently, ozonated water, • Convenient for usage
bioactive glasses, nanosilver and various acids are also • Good shelf-life and easy storage.
being used as irrigating agents. Currently, there is no single irrigant that can fulfill
all the required criteria. Therefore, combinations of
Objectives various irrigants are suggested for getting the desired
The primary objectives of root canal irrigation are: results.
• Reduction of intraradicular microorganisms and
neutralization of endotoxins in an infected canal. Classification
• Dissolution of vital or necrotic pulp tissue, to remove There is no definite classification of irrigating solutions.
pulpal remnants from accessory canals and other Various authors have classified irrigating solutions; the
irregularities where the instruments cannot reach. accepted ones are:

290

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 Root Canal Irrigants and Medicaments 291

a. Tagger’s Classification d. Sikri’s Classification

Tagger’s classification is based on functions, as: The classification of irrigants as proposed by the author
i. Working solutions (solutions having certain specific is described in Flowchart 18.1.
function, such as tissue dissolution/chelation; used
in smaller quantities and for a longer time). COMMONLY USED IRRIGANTS
ii. Irrigants (solutions mainly meant for physically
1. Normal Saline
flushing out the debris; used in larger quantities).
Normal saline is a chemically inactive irrigant. Its main
b. Stock’s Classification action is to physically flush out debris from the root
Stock’s classification is based on chemical activity of canal. It also provides minor lubrication. Since, it is very
the irrigants, as: mild in action, it can be used as an adjunct to chemical
irrigants. It is preferably used as final rinse to remove
i. Chemically inactive solutions, viz. water, saline and
any chemical agent left after root canal preparation and
local anesthetic solution
irrigation.
ii. Chemically active solutions, viz. alkalis, acids,
chelators, oxidisers, antibacterials, detergents and Advantages
enzymes. • Biocompatible
• No adverse reaction, even if extruded periapically,
c. Walton’s Classification because of its isotonicity to blood.
Walton’s classification is based on functions of irrigants,
Disadvantage
as:
• Does not perform other desired functions of an
i. Irrigants irrigant, like disinfection, tissue dissolution, removal
ii. Dentin softners of smear layer, etc.
• Chelators
• Decalcifiers 2. Sodium Hypochlorite
iii. Lubricants Sodium hypochlorite is a clear, pale, green-yellow liquid
iv. Desiccants. with strong odor of chlorine. Sodium hypochlorite

Flowchart 18.1: Classification of irrigants

18

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 292 Essentials of Endodontics

solutions have been used as wound irrigants since long remove organic debris more efficiently as compared
and also as an endodontic irrigant. 1.0–5.25% sodium to cold solution. It is established that the tissue
hypochlorite solutions are being used as irrigant dissolving efficacy of 1.0% sodium hypochlorite at
depending upon the requirements. 45°C is as good as 5.25% sodium hypochlorite at
Sodium hypochlorite is a reducing agent having 5.0% 20°C.
available chlorine. It is highly alkaline with a pH of iii. Use of ultrasonics: The use of ultrasonic agitation
11–11.5. increases the effectiveness of sodium hypochlorite
especially in the apical third of the root canal.
Properties
Passive ultrasonic activation with a Ni-Ti tip has
i. Proteolytic action: It is a hydrolyzing agent and can shown to produce superior tissue-dissolving effects
dissolve pulp within 20 minutes to two hours. The as compared to sonic activation.
removal of organic tissue by sodium hypochlorite
iv. Volume and concentration: It is established that higher
is by the release of hypochlorous acid, which reacts
concentration of sodium hypochlorite (5.25%) has
with insoluble proteins to form soluble poly-
more tissue dissolving activity than lower
peptides, amino acids and other by-products.
concentration (0.5–1.0%). Volume of solution is
ii. Bactericidal and virucidal: When sodium hypochlorite considered more critical for disinfection than its
comes in contact with organic debris/pulp tissue, concentration. The lower and higher concentration
hypochlorous acid is formed. The latter is able to are equally effective in reducing number of bacteria
penetrate the bacterial cell, oxidizes the sulfhydryl in infected root canals.
groups of the bacterial enzymes and disrupts the
v. Use of fresh solution: Sodium hypochlorite decom-
metabolism, which eventually leads to their death.
poses quickly. The solution should be fresh before
iii. Alkalinity: Sodium hypochlorite has a high pH of use. Fresh solution has better antibacterial and
11–11.5, which is effective in eliminating anaerobes. tissue dissolving effects. The solution should be
Disadvantages stored in opaque containers.
• Causes mild to severe cellular damage
• Toxic if extruded beyond the apex (severity depends
upon the concentration and volume)
• High surface tension, which decreases its dentin
wetting capacity
• Caustic and can cause inflammation of gingival
tissue and skin, when in contact
• Unpleasant taste and odor
• Vapors can irritate the eyes
• May corrode root canal instruments
• Not effective against Enterococcus faecalis
• Not substantive.

Increasing the Efficacy of Sodium Hypochlorite

The efficacy of sodium hypochlorite can be increased
by any of the following methods:
i. Altering the pH: The state of available chlorine is
dependent on pH of the solution; above pH 7.6, the
predominant form is hypochlorite and below this
value, it is hypochlorous acid. Both forms are 3. Chlorhexidine
extremely reactive oxidizing agents. The efficiency Chlorhexidine is a potent antiseptic, which is widely
of pure hypochlorite solution having pH of 12 is used for chemical plaque control in the oral cavity.
better than the routinely used sodium hypochlorite. Aqueous solutions of 0.1 to 0.2% are generally
ii. Heating (increase in temperature): The increase in recommended for plaque control. 2.0% concentration

18 temperature of sodium hypochlorite solution

improves its efficiency, mainly the tissue-dissolution
capacity. Further, the heated hypochlorite solutions
is effective as an irrigant. Chlorhexidine is a broad-
spectrum antimicrobial agent, effective against gram-
negative and gram-positive bacteria.

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 Root Canal Irrigants and Medicaments 293

Chlorhexidine antimicrobial activity is pH dependant; Disadvantages

the optimal range being 5.5–7.0. It is a strong base and • Unable to dissolve necrotic tissue remnants
is most stable in the form of its salts, i.e. chlorhexidine • Reduced action in the presence of exudates
gluconate. At low concentration, it acts as a bacterio- • Does not inactivate lipopolysaccharide, which is a
static; whereas, at higher concentrations it causes structural component of the gram-negative bacteria's
coagulation and precipitation of cytoplasm and outer cell wall
therefore acts as bactericidal. The cationic properties • Less effective against gram-negative bacteria
of chlorhexidine allow them to bind electrostatically to • Does not remove smear layer
root dentin surface. Heating of chlorhexidine solution
• Antimicrobial effect of chlorhexidine is reduced by
also improves its efficiency.
the presence of inflammatory exudates, serum
0.1% octenidine has the same potential as chlor- albumin and dentin matrix, etc.
hexidine.
• May cause hypersensitivity reactions like contact
Cetrehexidin (combination of 0.2% chlorhexidine and dermatitis (2.0% concentration may irritate skin).
0.2% cetrimide) has also been tried as irrigant. The solu-
tion provides better penetration of chlorhexidine into 4. QMix
the dentinal tubules and has better antimicrobial efficacy.
QMix is a mixture of EDTA, chlorhexidine and a
The combined use of chlorhexidine and sodium
detergent, available as a clear solution. The low surface
hypochlorite is controversial. Many studies indicate that
tension of the solution is good characteristic to be used
the reaction product of chlorhexidine and sodium
as an irrigant. It is equally effective in smear layer removal.
hypochlorite, i.e. Parachloroaniline has carcinogenic
It is also considered effective disinfectant against the
and mutagenic potential. Further, the combination may
root canal biofilm (penetrate dentinal tubules).
discolor the tooth. However, a few authors found the
combination more effective as root canal irrigant. 5. Hydrogen Peroxide
Properties Hydrogen peroxide is being used in dentistry in various
i. Substantivity (the continuous/residual effect of forms. 3.0% concentration is preferred as root canal
chlorhexidine): 2.0% chlorhexidine can cause irrigant.
residual antimicrobial activity for 72 hours when
Properties
used as an endodontic irrigant.
i. Various concentrations of hydrogen peroxide are
ii. Chlorhexidine is more effective than sodium hypo- chemically stable. 3.0% H2O2 is considered active
chlorite against resistant Enterococcus faecalis, against bacteria, yeasts, and viruses due to the
which are commonly found in failed endodontic production of hydroxyl free radicals, which attack
cases. several cell components.
Advantages ii. The antimicrobial efficiency and the tissue-
• Broad-spectrum antimicrobial (effective even against dissolving capacity of hydrogen peroxide are poor
Enterococcus faecalis and Eubacterium nucleatum in comparison with sodium hypochlorite. The alter-
associated with endodontic failures) nate use of sodium hypochlorite and hydrogen per-
• Bacteriostatic at a concentration of 0.12–2.0% (causing oxide would be beneficial in reducing intraradicular
increased cell permeability and leakage of important microorganisms, could not be substantiated.
intracellular components) iii. The combination of chlorhexidine and hydrogen
peroxide at low concentrations was found to have
• Bactericidal at a concentration above 2.0% (causing
greater antimicrobial activity.
precipitation of bacterial cytoplasm and ultimately
cell death) 6. Iodophors (Iodine Potassium Iodide)
• Effective antifungal agent
Iodophors are complexes of iodine and a solubilizing
• Better absorption agent potassium iodide, which acts as a reservoir of the
• Substantivity (binds to dentin and enamel; sustained active ‘free’ iodine. The iodophors are strongly germi-
release) cidal; however, they are considered less active against
• Effective in infected canals and retreatment cases fungi and spores. The action of iodine is rapid, even at
• Because of its inhibitory effect on the enzyme MMP2,
it can significantly improve the stability of resin-
dentin bond.
low concentrations. Iodine penetrates into micro-
organisms and attacks key groups of cell molecules,
such as proteins, nucleotides, etc. resulting in cell death.
18

t.me/Dr_Mouayyad_AlbtousH
 294 Essentials of Endodontics

Combinations of iodine potassium iodide and limitation of not removing the smear layer especially
chlorhexidine kill resistant bacteria more efficiently. the inorganic material, is a matter of concern.
Demineralizing agents, such as ethylenediaminetetra-
Advantages
acetic acid (EDTA) and citric acid have been used as
• Active against a wide spectrum of microbes adjuvants in root canal therapy to effectively remove
• Low tissue toxicity the inorganic content of the smear layer. The removal
• Effective disinfectant for infected dentin surface of the smear layer is a crucial step to facilitate
• An effective irrigant; especially against enterococci disinfection of the root canal system. First, the micro-
• Biocompatible (iodine compounds are less cytotoxic organisms embedded in the smear layer are eliminated
and irritating to vital tissues than other commonly and canal cleanliness is improved. Secondly, it has been
used irrigants). shown that the removal of smear layer improves the
antimicrobial effect of intraradicular medicaments in
7. Chlorine Dioxide the deeper layer of dentin. The commonly used
Chlorine dioxide is familiar household bleach, commonly chelating agents as root canal irrigants are:
used to eliminate contaminants from drinking water.
Chemically, it is similar to chlorine/hypochlorite. Its a. EDTA
disinfectant properties have been established. It is used It is the most commonly used chelating agent. It helps
in routine as surface disinfection and in dental waterline in negotiation of narrow and calcified canals. It forms
treatment. Its powerful oxidizing properties kill bacteria complexes with calcium. EDTA decalcify dentin up to
by disrupting the transport of nutrients across the cell the depth of 20–30 μm; however, the action of EDTA is
wall. This strong antibacterial activity makes it a self-limiting because the chelator gets used up. For
potentially useful endodontic irrigant. Chlorine dioxide optimal cleaning of root canals, EDTA should be used
is very efficient in dissolving organic tissues; as good at neutral pH and with lower concentrations (15–17%
as sodium hypochlorite. accepted). EDTA has almost no antibacterial activity,
is highly biocompatible, can demineralize intertubular
Advantages dentin and reduces the surface hardness of root dentin.
• Strong antimicrobial properties EDTA should be used with caution inside root canals
• Effective tissue dissolving ability because prolonged exposure to EDTA may weaken root
• Ease of use dentin and may increase the risk of creating a perfora-
• Easy availability. tion during mechanical root canal instrumentation.

8. Carbamide Peroxide (Glyoxide) Properties

The properties of 17% EDTA are:
Carbamide peroxide is available in an anhydrous
i. Chelates the inorganic components of the dentin
glycerol base; 10% concentration is used as irrigant. It
ii. Soften dentin effectively (KHN of dentin is reduced
is more germicidal than hydrogen peroxide. It has
almost 5–10 times); Demineralizes 20–30 μ of dentin
strong lubricating effect, facilitating negotiation of when used for five minutes
narrow and/or curved canals. Sodium hypochlorite iii. Good cleaning efficacy between 1–5 minute
when mixed with glyoxide, release (O), which effectively working time
kills microorganisms in the root canals. iv. Removal of smear layer when used alternatively
9. Maleic Acid with sodium hypochlorite (sodium hypochlorite
removes organic contents; whereas, EDTA removes
Maleic acid, a mild organic acid, is an effective irrigant inorganic material)
when used in concentration of 5–7%. It effectively v. Help in detaching biofilm from root canal walls
removes smear layer from the root canal walls; vi. Relative non-toxic (may cause irritation)
considered better than 17% EDTA and QMix. It is less vii. Effective lubricant
toxic as compared to 17% EDTA. It has also shown to
viii. Reduces time necessary for débridement and
improve the bond strength of resin sealer to root canal disinfection
dentin when compared to 17% EDTA.
ix. Aids in negotiating narrow/calcified canals
10. Chelating Agents x. Biocompatible.

18 Sodium hypochlorite is considered to be the most

desirable endodontic irrigant, effectively removing the
organic contents from the root canals; however, the
Functions
• Increased depth of penetration.
• Better débridement caused by foaming action.

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 Root Canal Irrigants and Medicaments 295

• Facilitate emulsification of organic tissue (collagen ineffective in eradication of biofilm (especially,

in the pulp is quite elastic and difficult to remove; Enterococcus faecalis). It can be used alone or in
resists repeated attempts of removal by getting combination with other irrigants; however, EDTA or
stretched and then collapsing back to its original citric acid should never be mixed with sodium hypo-
position). EDTA helps to emulsify the pulpal tissue chlorite because they strongly interact with sodium
and thus aids in its easy removal. hypochlorite. This reduces the available chlorine in the
• Holds the debris in suspension by encouraging combined solution, thus making it ineffective against
floatation of pulpal remnant, which can be effectively root canal microorganisms.
removed by a subsequent sodium hypochlorite
irrigation. c. Hydroxy-ethylidene Bisphosphonate (HEBP)
Hydroxy-ethylidene Bisphosphonate (HEBP) in
Different forms of EDTA varying concentrations (9–18%) has chelating properties
Different forms (mainly paste and liquid) of EDTA and can be used as an irrigating solution. The
chelators are: demineralization induced by HEBP was significantly
Paste chelators slower as compared to 17% EDTA. The advantageous
• Calcinase slide (15% EDTA + 58–64% water) property of HEBP as chelating agent is that it shows
• RC Prep [15% EDTA + 10% urea peroxide + glycol only short-term interference with sodium hypochlorite.
(ointment based)] HEBP has been used to prevent bone resorption in
patients suffering from osteoporosis or Paget’s disease.
• Glyde file/file care EDTA (15% EDTA + 10% urea
The overall effects of HEBP are considered equivalent
peroxide in aqueous solution)
to citric acid.
• File EZE (19% EDTA).
d. Salvizol
Liquid chelators
• Calcinase: (17% sodium edetate, sodium hydroxide Salvizol, a quaternary ammonium (detergent) material
and purified water) has been tried as an irrigant. It is established that
• REDTA: (17% EDTA + 0.84 gm cetrimide + sodium salvizol, with a neutral pH, has a broad-spectrum
hydroxide and distilled water) bactericidal activity and also the ability to chelate
calcium. Salvizol has effective cleaning potential and
• EDTAC: (15% EDTA + 0.75 gm cetavalon)
is biologically compatible. Its low-surface tension and
• DTPAC: (Diethyl-triamine-penta acetic acid +
chelating effect aids in biomechanical cleaning of the
Cetavalon)
root canal spaces. Salvizol induces irritation of tissue
• EDTA-T: [17% EDTA + tergentol (sodium lauryl similar to those of iodophors, but less as compared to
ether sulphate)] sodium hypochlorite or other quaternary ammonium
• EGTA: (Ethylene glycol + tetra acetic acid) compounds.
• CDTA: (1% solution of cyclohexane-1, 2-diaminetetra
acetic acid) e. Solvidont
• Tublicid plus: (Disodium EDTA dehydrate, benzal- Solvidont is bis-dequalinium acetate, used mainly as a
konium chloride, citric acid and phosphate buffer, disinfectant. It provides lubrication and is non-toxic. It
distilled water) is recommended as substitute for sodium hypochlorite,
• Hypaque: (5% sodium hypochlorite + 17% EDTA + especially in those patients who are allergic to the latter.
a high contrast injectable dye hypaque). The chelation properties of solvidont in removing the
smear layer coupled with low surface tension allowing
b. Citric Acid the solution to penetrate into the inaccessible areas,
Citric acid in varying concentrations has been used to make it an excellent irrigant.
remove the smear layer after root canal preparation.
10% citric acid has been established as a cheaper 11. MTAD
alternative to 17% EDTA. It acts by demineralizing the MTAD is a mixture of a tetracycline isomer (doxycycline:
intertubular dentin around the opening of the tubules; 3.0%, citric acid 4.25% and a detergent: Tween 80). It is
subsequently, enlarging the tubules. It has proven to mainly used as a final rinse before obturation.
be more biocompatible than 17% EDTA. Doxycycline with its low pH acts as a calcium chelator
The use of 10% citric acid as final irrigant has shown
good results, especially in smear layer removal;
however, even higher concentration (25%) was found
and cause root surface demineralization. Citric acid also
has demineralising potential. Doxycycline primarily
inhibit protein synthesis by binding to bacterial
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 296 Essentials of Endodontics

ribosomes. Doxycycline is active against wide range of

gram-positive and gram-negative organisms, but it is
not effective against fungi. Citric acid has antibacterial
properties but not effective against C. albicans.
Clinically, 1.3% sodium hypochlorite is used for 20
minutes followed by five minutes of MTAD to
effectively remove smear layer. The solubilizing effects
of MTAD on pulp and dentin are somewhat similar to
those of EDTA. The major difference between the
actions of these solutions is a high binding affinity of
the doxycycline present in MTAD for the dentin. The
three constituents of MTAD act synergistically against
bacteria. The combination of sodium hypochlorite and
MTAD has been advocated to remove the smear layer
and also to achieve substantial antimicrobial efficacy.
MTAD is effective against E. faecalis and is less toxic
than other agents, viz. 3.0% H2O2, EDTA and calcium
hydroxide. MTAD is found to be as effective as 5.25%
sodium hypochlorite and significantly more effective
than EDTA. A final rinse with MTAD might have a
negative effect on the bonding ability of both resin-
based and calcium hydroxide-based sealers. Its
effectiveness in apical third area is controversial; a few
studies observed not efficient (Maneini et al. 2009);
whereas, other studies consider it efficient (Torabinejad
et al 2003).

12. Tetraclean
Tetraclean, a modified form of MTAD, is also used as
an irrigant. MTAD and tetraclean differ in the concen- Fig. 18.1 Electrochemically activated water
tration of antibiotics (doxycycline 150 mg/5.0 ml for
MTAD and 50 mg/5.0 ml for tetraclean) and the kind principle of electrochemical activation is transferring
of detergent (tween 80 for MTAD, polypropylene glycol water into a metastable state via an electrochemical
for tetraclean). Tetraclean has the lower surface tension anode or cathode through the use of a reactor (Fig. 18.1).
values as compared to MTAD and sodium hypo- Electrochemical solution in anode and cathode
chlorite. It effectively disengages biofilm from the root chambers result in synthesis of two forms of solution:
canal walls. that produced in anode chamber is termed anolyte and
that produced in cathode chamber is catholyte.
13. Bioactive Glass
i. An ‘anolytic’ solution has high oxidation potential,
Bioactive glasses are a group of surface reactive glass- which makes it highly antibacterial
ceramics (SiO2 – Na2O – CaO – P2O5), exhibit anti- ii. A ‘catholytic’ solution with a high reducing
microbial activity by their ability to increase the pH potential, used as a detergent.
environment. The commercially available bioactive The electrochemically activated solutions are non-
glass (S53P4) when used in root canals, effectively kill toxic and their action is comparable to sodium
root canal microorganisms. Various studies have hypochlorite. Anolytic solutions are superoxidized
confirmed significant antibacterial activity against water and/or oxidative potential water.
almost all organisms when used in 50–100 mg/ml
concentration. The mechanism of action is not pH a. Superoxidized water (Sterilox): The saline water is
dependent and does not alter dentin. electrolyzed to form superoxidized water, which
contains hypocholorus acid and free chlorine radicals.

18
14. Electrochemically Activated Solutions Commercially, the solution is supplied as sterilox. The
Electrochemically activated solutions are produced solution is nontoxic; however, effectively kill micro-
from natural water and low concentration of salt. The organisms.

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 Root Canal Irrigants and Medicaments 297

b. Oxidative potential water: Oxidative potential water 16. Carisolv

is produced by electrolyzing sodium hypochlorite in a Carisolv is used for chemomechanical removal of caries.
special machine, called ‘aquacida’. This is effective It may have same potential as an irrigant as it is
against bacteria as well as viruses. The oxidative antibacterial and has collagen dissolving potential. Its
potential water is biocompatible and can remove smear use has not been established.
layer as well.
17. Photon-activated Disinfection (Photodynamic
15. Ozonated Water
Therapy)
Ozonated water is a powerful antimicrobial agent
The word ‘photodynamic’ implies applying dynamics
against bacteria, fungi, protozoa, and viruses. Ozone,
of photons of light on the biological molecules. It is also
a chemical compound consisting of three oxygen atoms
known as photon-radiations or phototherapy, which
(O3), is produced naturally by the following methods:
employs the photochemical interaction of three
i. Ozone is created when an oxygen molecule receives
components: light, photosensitizer and oxygen. It is
an electrical discharge (from thunderstorm)
based upon the principle that when photosensitizer is
breaking it into two oxygen atoms. The individual
excited by light source of suitable wavelength, it is
atom combines with another oxygen molecule to
activated and produce free radicals, which have site-
form O3 (ozone).
specific toxic effect on the cells. Two basic mechanisms
ii. Ultraviolet rays from sun help electric discharge
by which cell damage can occur are:
over natural oxygen of environment, creating ozone
layer. i. DNA damage
It is established that ozone at low concentration ii. Damage to cytoplasmic membrane allowing
(0.1 ppm) is sufficient to inactivate bacterial cells leakage of cellular contents or inactivation of
including spores. It is considered effective against membrane transport system and enzymes.
microorganisms; however, its role in eradicating
The commonly used photosensitizers are:
E. faecalis has not been established. Various studies have
confirmed that ozonated water is not effective against • Methylene blue
Candida albicans, E. faecalis and lipopolysaccharides in • Toluidine blue
root canal biofilms. • Tolonium chloride
It is used as a solution to soak surgical instruments. • Aluminium disulphonated phthalocyanine.
The advantages of ozone are its potency, ease of
Methylene blue is established photosensitizer that
handling, lack of mutagenicity and rapid microbicidal
is used in photodynamic therapy for targeting various
effects. Ozonated water has nearly the same anti-
gram-positive and gram-negative oral bacteria. A few
microbial activity as 2.5% sodium hypochlorite during
studies have shown incomplete destruction of oral
irrigation and is less toxic (Fig. 18.2).
biofilms to photodynamic therapy using methylene
blue. The reduced susceptibility has been attributed to
reduced penetration of the photosensitizer. To improve
upon this deficiency, drug delivery system was
developed, which significantly improved the clinical
efficacy of methylene blue.
Recently, polymer-based nanoparticles for photo-
sensitizer delivery and release system is being studied.
The advantages of nanoparticles containing photo-
sensitizers are:
• Larger concentrated mass for production of reactive
oxygen
• Limiting the target cell’s ability to pump the drug
molecule back, thus reducing the possibility of
multiple drug resistance

Fig. 18.2 Ozonated water

• Nanoparticles matrix is non-immunogenic
(nanoparticles showed time dependent release of
photosensitizer).
18

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 298 Essentials of Endodontics

18. Herbal Irrigants vii. Aloevera: Aloevera extract, especially the

The routinely used antimicrobial irrigants may lose the chloroform extracts, possesses good antibacterial and
effectiveness because of increased bacterial resistance anti-inflammatory potential. Various studies have
and other side effects. The alternative antimicrobial confirmed significant antimicrobial affect against
agents are being tried to overcome these limitations. E. faecalis.
Herbal products are gaining popularity because of their viii. Tea tree oil: Tea tree oil has significant anti-
high antimicrobial potential, biocompatibility and anti- inflammatory and antimicrobial properties. Tea tree oil
inflammatory properties. when compared with 3.0% sodium hypochlorite and
The commonly used herbal products as irrigants are: 2.0% chlorhexidine, was found to be better than sodium
hypochlorite and less effective than chlorhexidine
i. Turmeric (Curcumin longa): Turmeric (curcumin) is
against E. faecalis.
an established anti-inflammatory and antimicrobial
agent. Various authors have confirmed the antibacterial ix. Miswak-Siwak (Salvadora persica): It is established
potential of turmeric against Enterococcus faecalis. It is that 15% extract of Miswak-Siwak has significant effect
used as root canal irrigant as an alternative to sodium against both aerobic and anaerobic bacteria. Its effect
hypochlorite. It is an effective irrigant, especially in was found to be comparable with 5.25% sodium
failed root canal cases. hypochlorite and 0.2% chlorhexidine.
ii. Babool (Acacia nilotica): Babool (Acacia nilotica) is x. Lemon grass (Cymbopogon citratus): Lemon grass
an excellent antimicrobial agent, used in routine as a was found to have a significant antimicrobial efficacy
root canal irrigant. It is also effective against fungi and against Candida albicans when compared to 2.0%
viruses. Various studies have confirmed its chemical chlorhexidine gluconate when used as an endodontic
efficacy, especially against Enterococcus faecalis. In irrigant.
comparative studies, 50% concentration has been found
to have best antimicrobial potential. xi. Cashew: The leaf extract of Anacardium occidentale
when used as an endodontic irrigant, had antibacterial
iii. Neem (Azadirachta indica): Neem extract has been activity against E. faecalis which was equivalent to 2.0%
widely used to minimize dental plaque. It is potent anti- chlorhexidine gluconate. However, its antifungal
bacterial and anti-inflammatory agent and is also activity against C. albicans was poor as compared to
biocompatible. Studies have confirmed its effectiveness 2.0% chlorhexidine gluconate.
against E. faecalis and found Neem to be superior to
sodium hypochlorite. xii. The following herbs have also been tried as root
canal irrigant, establishing their antibacterial potential:
iv. Propolis: Propolis has been used as pulp capping • Garlic (Allium sativum)
agent and also as mouth rinse in the treatment of perio- • German chamomile
dontitis. Propolis is also used as intracanal medicament
• Casearia sylvestris
and also as a storage media for avulsed teeth to
maintain vitality of periodontal ligament. Extract of • Carvacrol
propolis (natural substance collected by honeybees from • Acacia nilotica
trees) induces hard tissue formation in pulp capping • Psoralea corylifolia
and pulpotomy. Its effectiveness as root canal irrigant
has been found to be comparable to sodium hypochlorite. 19. NanoCare Plus
NanoCare plus is a nanosilver and nanogold based root
v. Green Tea (Camellia sinensis): Green tea has
canal irrigant. It is available both in liquid form (as
significant anti-inflammatory, antimicrobial and
irrigant) and paste form (as intracanal medicament).
probiotic properties. It is a potent root canal irrigant
NanoCare plus is preferably used as final rinse. The
having scavenging properties. Studies have confirmed
main characteristic of NanoCare plus is that it leaves a
the antimicrobial potential of green tea against E. faecalis.
layer of nanosilver and nanogold particles on the canal
It is considered as a better irrigant as compared to
surface, which has a strong bacteriostatic effect. Low
sodium hypochlorite.
surface tension of ‘NanoCare+’ allows nanoparticles to
vi. Triphala: Triphala extract is rich in citric acid, which get into the smallest intricacies and even dentinal

18 is effective chelator to remove smear layer from root

canal walls. Its efficacy is considered equivalent to
sodium hypochlorite.
tubules. It is established that it helps in preventing
bacterial colonization, especially Enterococcus faecalis
(Fig. 18.3).

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 Root Canal Irrigants and Medicaments 299

surface tension of the irrigant more will be its

wettability and more will be its penetration into
narrow/inaccessible areas and better will be the
débridement. The temperature of the irrigant is also
important as it has been shown that if sodium
hypochlorite is warmed (60–70°C) before irrigation, it
is much more effective as a tissue solvent. The irrigant
should properly contact the canal substrate to be able
to dissolve/flush out the debris. So, it is critical that
the canals should be mechanically enlarged to carry the
solution to the apical extent of canal preparation.
Fig. 18.3 NanoCare plus Choosing the Right Irrigant
Nanosilver particles exhibit properties such as high The choice of irrigant should depend upon the clinical
catalytic capabilities and ability to generate reactive situation; the clinical case may warrant the use of
oxygen species. Nanosilver particles react with three combination of irrigants. Choosing the right combina-
main components of the bacterial cell to produce the tion of irrigant is essential to prevent its misuse. The
bactericidal effect; the cell wall (plasma membrane), chemicals used to clean infected canals should be
cytoplasmic DNA and bacterial proteins. Application combined in such a manner so that they can be effective
of nanosilver particles prevents the biofilm formation as irrigant rather than act on each other.
and inhibit bacterial growth. Various studies have Sodium hypochlorite appears to be the most
confirmed its efficacy as root canal irrigant. Its non- desirable endodontic irrigant solution fulfilling the
cytotoxic affects to both mouse fibroblasts and maximum requirements of an ideal irrigant. It can
periodontal ligament cells have also been established. be employed practically for all cases, except when there
A new irrigation solution has also been tried are chances of periapical extrusion/presence of active
(Moghadas et al 2012), containing silver nanoparticles pus drainage. It has excellent ability to dissolve necrotic
and two other components, ethanol and sodium tissue and the organic components of the smear layer.
hydroxide. The combination provides essential However, it cannot dissolve the inorganic dentin
capabilities of an ideal root canal irrigant. particles. In addition, calcifications hindering mechanical
Silver ions have been established as an antimicrobial preparation are frequently encountered in the canal
agents. Ethanol, being good disinfectant, reduces system. Demineralizing agents such as ethylene-
surface tension of the solution facilitating penetration diamine-tetra acetic acid (EDTA) and citric acid are
of nanosilver containing solution into accessory canals recommended as adjuvants in root canal therapy.
and dentinal tubules. Once the cleaning and shaping procedure is
Sodium hydroxide dissolves and neutralizes soft completed, canals can be thoroughly rinsed using
pulpal tissues, remove the organic portion of smear aqueous EDTA or citric acid (chelators) for removal of
layer, facilitating nanosilver particles to penetrate smear layer. Generally each canal is rinsed for at least
deeper into dentinal tubules and other intricacies of one minute using 5.0 to 10 ml of the chelator agent.
pulp spaces. The authors have observed the effective- Prolonged exposure to chelators such as EDTA may
ness of this combination as good as 5.25% sodium weaken root dentin.
hypochlorite. A final rinse with an antiseptic solution is always bene-
The comparative evaluation of commonly used ficial. The choice of the final irrigant depends on the next
irrigants are summarized in Table 18.1. treatment step, i.e. whether an intervisit dressing is
planned or not. If calcium hydroxide is used as intra-
Efficacy of Irrigants canal medicament, the final rinse should be with sodium
The efficacy of irrigants depends upon various factors. hypochlorite, as these two chemicals are complementary.
The cleaning efficacy of the irrigant is directly If the canal walls are perceived to be clean of debris/
proportional to the volume and the frequency of the necrotic tissue, chlorhexidine would be the most
irrigant used. It is important that canal should be promising agent as a final irrigant. It has the property
irrigated copiously during mechanical preparation after
using each instrument in sequence. The change of
irrigants may enhance the efficacy. The lower the
of substantivity (affinity to bind dental hard tissues,
slow release and prolonged antimicrobial activity).
Hence, a final irrigation using a chlorhexidine solution
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 18
Table 18.1 Comparative evaluation of commonly used endodontic irrigants
Irrigant Concentrations Antimicrobial Tissue solvent Biofilm/smear Toxicity/ Miscellaneous (additional
agent (normally used) activity potential layer removal cytotoxicity characteristics)
potential
Sodium 0.5–5.25% Antibacterial and Dissolves only Higher concen- Tissue irritation • With chlorhexidine, forms parachloranaline
hypochlorite antifungal organic matter tration is effective • EDTA reduces tissues dissolving property of
sodium hypochloride
• Forms calcium chlorite (antibacterial) with
calcium hydroxide

Chlorhexidine 0.2–2.0% Antibacterial and Nil May not disrupt Mild to moderate Sodium hypochlorite and EDTA in combination
300 Essentials of Endodontics

antifungal smear layer cytotoxicity with chlorhexidine form precipitate

Octenidine 0.1% Antimicrobial Nil Biofilm disruption Mild to moderate Not established (tried as alternative to chlor-
cytotoxicity hexidine)
EDTA (chelating 15–17% No antimicrobial Pulp and dentin Removes smear Nil Chlorhexidine and EDTA form white precipitate
agent) activity layer
MTAD NA Antimicrobial (superior Pulp and dentin Removes smear Biocompatible Effectively removes smear layer
to chlorhexidine) layer
No antifungal activity

Iodophors N/A Effective antimicrobial Mild effect Disrupts biofilm Biocompatible Effective disinfectant; attack cell molecules
resulting in cell death

Ozonated N/A Antimicrobial Mild Not effective Biocompatible Not effective against Candida albicans and
water E. faecalis
Herbal irrigants N/A (concen- Antimicrobial Mild Not effective Biocompatible As effective as sodium hypochlorite; few are

t.me/Dr_Mouayyad_AlbtousH
tration varies) antifungal also
Tetraclean NA Antimicrobial (superior Pulp and dentin Removes smear Biocompatible Effective irrigant
to chlorhexidine) layer
No antifungal activity
Q mix NA Antimicrobial No Removes biofilm Nil Forms precipitate with sodium hypochlorite
Maleic acid 5.0–7.0% Antimicrobial Mild effect Effective in Mild Improves bond strength of resin sealers to root
removing smear dentin
layer

Bioactive glass N/A Antimicrobial Mild effect May not disrupt Nil Long-term evaluation still to be documented
smear layer
NanoCare Plus N/A Antimicrobial Mild effect Effective in Nil Long-term evaluation still to be documented
removing smear
layer
 Root Canal Irrigants and Medicaments 301

Table 18.2 Protocol for use of irrigants

Condition Irrigant
Necrotic pulp • Sodium hypochlorite
• Final rinse with chlorhexidine
Vital pulp exposure • Sodium hypochlorite
• Final rinse with EDTA
Calcified/sclerotic canal • EDTA
• Sodium hypochlorite
Infected canal (exudate • Sodium hypochlorite
present) • Chlorhexidine
Periapical abscess (to • Hot water/saline
establish drainage) • Sodium hypochlorite
Open apex/apical perforation • Chlorhexidine
Curved canals • Glyoxide
• Sodium hypochlorite
Fig. 18.4 Irrigation needles with side opening
Canals left open for drainage • 3% hydrogen peroxide
• Saline
Retreatment cases • Chlorhexidine
• Sodium hypochlorite
Removing smear layer in • EDTA/citric acid
noninfected cases • Sodium hypochlorite

appears advantageous, especially in retreatment cases.

The common protocol for use of irrigants is tabulated
in Table 18.2.
(If residual hypochlorite is still present in the canal,
irrigation with chlorhexidine will precipitate in the form of a
brownish-reddish mass. The precipitates hinder the action of
chlorhexidine and may discolor the tooth. The canal should
be dried using paper points before the final chlorhexidine rinse.)

IRRIGATING TECHNIQUES
Efficacy of root canal irrigation depends upon many
factors, such as diameter of the prepared canal, canal
curvatures, depth of needle insertion into root canal
and volume/concentration of the solution used. Fig. 18.5 Irrigation using side vent needle (left) and
Various techniques have been tried to achieve effective conventional (right)
irrigation. The techniques are:
half-way into the canal. The irrigant when pushed with
1. Conventional Technique pressure will not extrude into the periapical areas. In
A small gauge needle (27 or 28 gauge) is used in routine case the needle is closed on top and has side openings,
to irrigate root canals. The irrigation needle gauge and the same can be inserted up to the apical third area of
the amount of root canal widened affect the cleaning the root canal. The irrigant when pushed will be
efficacy. The ‘gauge’ unit is separate entity and is not circulated along the canal walls, without disturbing the
related to the size of the endodontic instruments. periapical areas (Fig. 18.5). Slight agitation can
According to ISO 9626 standards, the diameter of the be achieved by moving the needle up and down in the
needle according to gauge is: 21 (0.8 mm), 23 (0.6 mm), root canal. Gutta-percha point can also be used to
25 (0.5 mm), 27 (0.4 mm), 30 (0.3 mm) and 31 (0.25 mm). agitate the irrigation solution. The modified needles

18
The needle may have one opening on top or one/two/ used in irrigation are:
many openings on the sides (Fig. 18.4). In case the i. Max-i probe: The max-i-probe irrigation needle
needle has opening on top, the same should be inserted provides effective patient comfort and safety in

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 302 Essentials of Endodontics

irrigating root canals. It is also used for irrigating

periodontal pockets. It has rounded end and one
side/open port. It is available in five sizes; 23 gauge
(light blue), 24 gauge (violet), 25 gauge (orange),
28 gauge (red) and 30 gauge (blue) (Fig. 18.6).
ii. Cala-sept needle: The needle provides excellent
irrigation with its double side ports. It is available
in two sizes, 27 gauge (gray) and 31 gauge (violet).
iii. Vista-probe irrigating tips: These are bendable, one
inch needle tip, designed to irrigate subgingival
surgical sites and sulcus. It has universal luer-lock
design with closed end and side port delivery. It is
available in 23, 27 and 30 gauges.
iv. Ni-Ti superflex: Ni-Ti superflex has 2.5 times more
flexible tip. It has adjustable needle angle for longer
life and produces less clogging. It is available in 30
gauge with luer-lock system.
v. NaviTip and NaviTip Fx: Flexible irrigating tips, Fig. 18.6 Maxi-i probe
available in different lengths (17 mm, 21 mm,
25 mm and 27 mm) and in two sizes (gauge 29 and
gauge 30) (Fig. 18.7). The tips are effective in
irrigation, especially at the apical areas. NaviTip
Fx is modified version, wherein a small brush is
attached at the opening (Fig. 18.8). The brush has
been observed to effectively clean the occlusal
portion of the root canal; however, the dislodge-
ment of brush bristles inside the apical aspects
of the root canal may lead to difficulties for the
operator.
The conventional techniques may utilize manual
agitation with needles, gutta-percha or brushes. Fig. 18.7 NaviTip

Irrigation activation
Manual activation Machine assisted activation
• Syringe irrigation with • Sonic (endoactivator, vibringe,
different needles rispisonic files)
• Manual agitation moving • Ultrasonic agitation
files/gutta-percha • Rotary brushes (canal brush)
• Endobrush/NaviTip FX • Pressure alteration devices
(Endovac, RinsEndo)
• Continuous irrigation with
rotary techniques (Quantec)
Fig. 18.8 NaviTip Fx

2. Sonic Irrigation sized polymer tips (Fig. 18.9). The tips are color coded
Sonic irrigation operates at lower frequency (less than according to their sizes; 15/02 – yellow, 25/04 – red
6 kHz) and is as effective as ultrasonic agitation of and 35/04 – blue. The handpiece provides three-speed
irrigant solution. The devices used are: motor option, viz. high, medium and low. The operator
is to decide the speed settings depending upon the

18
a. EndoActivator System clinical experience. The activation tips are preferably
The EndoActivator system is comprised of cordless, to be used for once only. Re-using the tips may lead to
battery operated handpiece along with three different cross-contamination. Vibrating the tips and their up and

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 Root Canal Irrigants and Medicaments 303

3. Ultrasonic Irrigation
In ultrasonic irrigation system, the irrigant is delivered
to the root canal by a syringe needle (Fig. 18.11a to c).
The piezoflow irrigation needles are used in conjunction
with a piezoelectric ultrasonic energy generating unit
Fig. 18.9 Endoactivator

down movement produces a hydrodynamic pheno-

menon (active irrigation). Such a fluid activation help
in cleaning all aspects of the root canal system.
The EndoActivator system provides safe and
effective method to clean the canal. The hydro-
dynamic activation facilitates penetration and flow
of irrigant into inaccessible areas of the root canal
spaces.
Recently, pressurized water irrigation technique
Fig. 18.11a Ultrasonic device
(AquaPick device), when compared with sonic
irrigation device (Endoactivator), has shown promising
results, especially irrigation of apical third area.

b. Vibringe System (Sonic Activation)

It is an irrigation device that combines manual delivery
and sonic activation of the solution. The vibringe is a
cordless handpiece that fits in a special disposable 10 ml
luer-lock syringe (Fig. 18.10) that is compatible with
any irrigation needle. The ergonomic designed vibringe
system features single-button operation, battery charge
indicator, auto shut off and white LED light for user
feedback. The battery sonically activates the irrigating
solution. Vibringe system is significantly better than
manual irrigation; however, not as effective as passive
ultrasonic irrigation. Fig. 18.11b Ultrasonic needle

Fig. 18.10 Vibringe system syringe Fig. 18.11c Ultrasonic activation of irrigant solution
18

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 304 Essentials of Endodontics

to provide the energy for tip oscillation. A syringe or The handpiece is energised by dental compressor.
other irrigation source is attached to the luer-lock 65 ml of rinsing solution oscillating at a frequency of
connection on the ultrasonic needle. Removal of irrigant 1.6 Hz is transported to the root canal through the
is through the conventional suction. During ultrasonic cannula. Because of the pulsating nature of the
activation, a 25 gauge irrigation needle is used. The irrigating solution, it effectively irrigates the apical
needle is simultaneously activated by the ultrasonic areas. During suction, the solution is aspirated back
handpiece, while an irrigant is delivered from a luer- from the root canals.
lock irrigation delivery syringe. The irrigant is It is established that the pressure created by
effectively delivered at the apical area. Various studies RinsEndo irrigation is lower than the pressure created
have established significant efficacy of ultrasonic by a syringe during manual irrigation. RinsEndo is
irrigation in both vital and nonvital teeth. compatible with all types of irrigating solutions. It is
considered as an effective irrigating modality.
4. Negative Pressure Irrigation
b. Endovac System
a. RinsEndo system
The Endovac system (apical negative pressure
The RinsEndo system (negative pressure irrigation)
irrigation) utilizes three components: the masters tip,
comprises of a handpiece, 20 disposable cannulas with
microcannula and the macrocannula. The masters tip
7.0 mm aperture and three 5.0 ml syringes carrying
delivers and evacuates the irrigant simultaneously. The
irrigant (Fig. 18.12). RinsEndo can be autoclaved.
tip is connected to the irrigation syringe and the
evacuation hood is connected to the high speed suction,
preferably macrocannula is connected via tubing to
high speed suction. The plastic macrocannula has an
open end that measures ISO size 55 with a 0.02 taper.
The stainless steel microcannula has 12 small, laterally
positioned, offset holes in 4 rows of 3, with a closed
end measuring ISO size 32. The microcannula can be
used at working length in a canal enlarged to ISO size
35 or larger (Fig. 18.13).
During irrigation, the tip delivers irrigation solution
to the pulp chamber and also evacuates the excess
Fig. 18.12 RinsEndo system irrigant. The cannulas in the root canal exerts negative

a b

18
c d

Fig. 18.13 Endovac system: (a) Endovac tubing and vacuum attachment; (b) Macrocannula; (c) Microcannula;
(d) Evacuation tip

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 Root Canal Irrigants and Medicaments 305

pressure that pulls irrigant from the canals to the suction 6. VATEA Self-adjusting file (SAF) system
unit. Various studies comparing Endovac system with The VATEA irrigation system is an integral part of the
other irrigation modules have confirmed its ability of self-adjusting file (SAF) rotary system. The irrigation
thorough irrigating/cleaning the root canals. delivery unit is attached to the handpiece during root
Advantages canal treatment procedure. The irrigant is delivered via
• Ability to safely deliver irrigant up to the working silicone tube to the endodontic file. The system is
length. effective in irrigating root canals and is considered
superior to the manual needle irrigation.
• Avoids sodium hypochlorite accidents (by keeping
the irrigating needle short of working length). Quantum irrigation system containing two irrigation
reservoirs, provides continuous irrigation during rotary
• Volume of irrigant delivered is more as compared
instrumentation.
to needle irrigation.
Disadvantage 7. Intracanal Aspiration Technique
Possibility of blockage of microcannula. It has been established that the effectiveness of irrigation
regimen depends upon the ability of irrigating agent
5. Irrivac Needle Pressure System to contact the entire canal system. It is usually difficult
The Irrivac is available in both positive needle pressure to contact the canal walls along apical constriction area;
version and a negative pressure version; the positive even smaller diameter needles are not effective. A new
pressure Irrivac for dispensing sodium hypochlorite for irrigation system is designed with an aim to inject irriga-
removing gross material and the negative pressure for tion solution up to apical area with injection needle and
final irrigation with sodium hypochlorite (Fig. 18.14a at the same time the solution is aspirated using
and b). aspiration needle to minimize extrusion through apical
This system includes titanium handpiece, solution foramen (Fig. 18.15).
reservoir and a specialized tubing, which is inert to The aspiration technique has shown promising
caustic irrigants. results in removing smear layer even from the apical
The negative needle pressure dispenses solution region of the canal, without extrusion of debris/irrigant
through the tubing funnel onto the needle, then flows solution out of apical foramen. It is recommended to
down the canal and finally suctioned up and removed. use Root ZX to monitor the activity of irrigant at the
The positive needle pressure dispenses solution apical-end area.
through the needle while the suction funnel sucks off
the irrigant solution from top of the canal. COMPLICATIONS DURING ROOT CANAL IRRIGATION
Irrigation techniques mainly tend to maintain balance
between cleaning efficacy and the patient safety.
Usually irrigation techniques are either delivery system
or activation or combination of both. Syringe irrigation
is common delivery system; whereas, sonic, ultrasonic
a

Fig. 18.14a and b Irrivac needle Fig. 18.15 Intracanal aspiration technique
18

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 306 Essentials of Endodontics

and laser are the activation systems. A few systems such • Edema may extend over the injured side of the face,
as RinsEndo follow both the protocol. upper lip, infraorbital region
The common complications during irrigation are: • Profuse bleeding from the root canal
• Profuse interstitial bleeding with hemorrhage of the
1. Apical Extrusion skin and mucosa (ecchymosis)
Inadvertent extrusion of irrigant during root canal • Chlorine taste and irritation of the throat
irrigation is a rare incident, though many studies have • Possibility of reversible anesthesia or paresthesia.
been reported.
Apical extrusion of debris caused by revolving Therapy
instruments in an apical direction is a common feature • Patient should be informed as regard kind and
during endodontic treatment. The extrusion is facilitated severity of complication
by instruments acting as a plunger, or by irrigation. • Local anesthesia for immediate relief of pain
The only way to prevent such extrusion would be an (analgesics in due course)
iatrogenic blockage of the apical foramen, which is not • Extraoral cold compression for reduction of swelling
feasible practically. Endodontic treatment will always (after 24 hours warm mouth rinses for stimulation
be a balance between blockage and some degree of of local systemic circulation)
extrusion of debris including irrigant. The extrusion of • Antibiotics are prescribed only in case of high-risk
irrigant solution may lead to: or evidence of secondary infection
• Antihistamines can be prescribed
A. Involvement of Surrounding
• In severe cases, patient may be referred to a hospital.
Anatomical Structures
a. Maxillary sinus: Inflammation and infection may C. Effect of Extrusion of Hydrogen Peroxide
spread from the root canal to the maxillary sinus. The symptoms of such type of incident may be similar
Maxillary sinus is in close proximity to root tips of to that of sodium hypochlorite: sudden and severe pain,
the maxillary posterior teeth. Periapical pathosis may swelling and emphysema, and crepitus. It is recommen-
result in destruction of the bone between root tip and ded that analgesics and antibiotics be prescribed. In
sinus floor. The symptoms of maxillary sinusitis are most cases, further intervention seems unnecessary and
similar to an acute pulpitis. swelling subsides in a few days.
b. Nerve injury: Apical extrusion of root canal filling
materials may result in severe damage to the D. Effect of Extrusion of EDTA
mandibular nerve, such as paresthesia, or in rare Extrusion of even a low concentration of EDTA solution
cases a hyperesthesia. The highest risk of iatrogenic through the apical foramen results not only in an
nerve damage exists during endodontic treatment irreversible decalcification of periapical bone, but can
of second mandibular molars. also have consequences for neuroimmunological
regulatory mechanisms.
B. Effect of Extrusion of Sodium Hypochlorite
Inadvertent extrusion of sodium hypochlorite beyond 3. Allergic Reaction
the apical foramen may occur in teeth with wide apical
foramina or when the apical constriction has been a. Sodium Hypochlorite
destroyed during root canal preparation or by resorp- Allergic reactions to sodium hypochlorite are unlikely,
tion. Additionally, extreme pressure during irrigation since both sodium and chlorine are essential elements
or binding of the irrigation needle tip in the root canal in the physiology of human body. Nevertheless, hyper-
with no release for the irrigant to leave root canal sensitivity and contact dermatitis may occur in rare cases.
coronally, may result in contact of large volumes of In case of hypersensitivity against sodium hypochlorite,
irrigant with the apical tissues leading to tissue necrosis. chlorhexidine should not be used. Alternatively, iodine-
Symptoms and recommended therapy in cases of potassium-iodide should be considered. Before use, any
extrusion of sodium hypochlorite into periradicular type of allergy against iodine must be ruled out.
tissues are:
b. Chlorhexidine

18
Symptoms It is relatively safe solution; rarely may induce allergic
• Immediate severe pain reaction. Allergic reactions such as anaphylaxis, contact
• Edema of neighboring soft tissues dermatitis, and urticaria have been reported following

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 Root Canal Irrigants and Medicaments 307

direct contact to mucosal tissue or open wounds; hypochlorite is a common household bleaching agent,
however, allergic reactions following root canal even small amounts may cause severe damage. These
irrigation with chlorhexidine have not been reported. mishaps should be prevented by proper protection of
the patient’s clothing. When using hand irrigation, one
c. Iodine-potassium Iodide should ensure that the irrigation needle and syringe are
Although the irritating potential of solution containing securely attached and will not separate during transfer
iodine is well known, there is no evidence on allergic or irrigation in order to prevent leakage on clothing.
reactions to iodine-potassium iodide. However, the
irrigant should not be used in patients with known or 8. Air Emphysema
suspected allergies to other iodine preparations. Air emphysema is defined as ‘the abnormal presence of
air under pressure where it is not normally present’, such
4. Inadvertent use of Sodium Hypochlorite as neck and face.
as Anesthetic Solution Such incident may occur while drying root canals
Owing to the excellent tissue-dissolving ability of with compressed air or when large amount of hydrogen
sodium hypochlorite, severe tissue and bone necrosis peroxide injected beyond the apical foramen, releases
may occur if sodium hypochlorite is inadvertently used oxygen and causes edema. The spread of air is rapid
as anesthetic solution. and extensive, resulting in immediate edema that may
Correct labelling and use of different colored tips are cross the facial midline. Intensity of pain varies but
safe and easy techniques to prevent such incidents. mostly last for a short duration.
The emphysema caused by endodontic therapy does
5. Damage to Eyes and Skin not require any treatment and mostly resolve within
Damage to the patient’s eyes may occur when needle one week.
and syringe are not connected tightly and get separated
during irrigation. This may be facilitated by inadequate 9. Postoperative and Inter-appointment Pain
irrigation pressure. When using irrigation needles with Postoperative pain may occur due to several reasons;
small diameter, it may be kept in mind that much more apical extrusion of the irrigant may be one of the
pressure is necessary to apply the same amount of the reasons. It is difficult to distinguish clinically, whether
solution in the same time, compared with tips with large postoperative discomfort is due to over instrumen-
diameter. When using such small needles, blockage of tation, extrusion of infected debris, extrusion of the
the tips may occur by deposition of sodium chlorite irrigant, or a combination of these factors.
crystals.
Skin injuries may occur following inadequate 10. Staining and Discoloration
isolation, leakage of the rubber dam, or splashing of The subsequent use of chlorhexidine and sodium
the irrigant. In order to prevent such mishaps, the hypochlorite may result in discoloration of dentin. The
patient’s eyes may be protected with glasses. brownish flocculate will occur with different concentra-
Additionally, patients should be asked to close their tions of the two solutions. The subsequent use of
eyes during irrigation. Luer-lock syringes should sodium hypochlorite and MTAD has been reported to
preferably be used to avoid separation from the result in a red-purple discoloration of the root and
irrigation needles. crown dentin.
Iodine-potassium-iodide has also been reported to
6. Airway Obstruction stain dentin.
Although root canal treatment needs to be performed
using a rubber dam, irrigant inadvertently may come 11. Other Side Effects of Irrigants
into contact with the airways. Corrosion of rubber dam clamps and endodontic
Sodium hypochlorite in contact with airway tissues instruments may occur as a result of long-time contact
may result in obstruction of the airways. with sodium hypochlorite.
Exposure of airways to citric acid may provoke Mercury release from amalgam fillings has been
bronchoconstriction. reported with the use of sodium hypochlorite.
Air contamination of the dental office with increased

18
7. Damage to Clothing concentrations of chlorine may affect skin, eyes and
The most common incident during root canal irrigation airways of the office personnel and the patient,
concerns damage to the patient’s clothing. As sodium especially when used with an ultrasonic unit.

t.me/Dr_Mouayyad_AlbtousH
 308 Essentials of Endodontics

Ultrasonic activation results in a fine fog of sodium Limitations and Contraindications

hypochlorite that may affect the eyes and skin of the • The chemical or therapeutic action of medicaments
patient, the operator and the supporting staff. depends on direct contact of the agent with microbes
or tissue.
INTRACANAL MEDICAMENTS • To be effective, the agents should remain chemically
Intracanal medicaments have traditionally been active between appointments.
considered hand-in-glove with Endodontics. They are • The allergic manifestations are common with
undoubtedly an integral part of treatment and important phenolics and aldehydes.
to the success of root canal therapy. The placement of a • Patients may also object disagreeable taste and
specific chemical agent during the inter-appointment pungent odor associated with phenolics.
period of a multi-visit procedure, forms part of the
chemical preparation of the root canal system; eradicat- Classification
ing microorganisms prior to permanent obturation.
The intracanal medicaments are classified as:
Rationale 1. Essential oils
The main rationale for using such medicaments is to i. Eugenol
help degrade residual microbial biofilm/organic tissue 2. Phenol based agents (phenolic compounds)
and to kill remaining bacteria. The medicament should i. Phenol/methylphenol (Cresol)/thymol
prevent bacterial recolonization of the root canal system, ii. Camphorated monochlorophenol (CMCP)
from either bacteria left after preparation or new invaders iii. Parachlorophenol (PCP)/camphorated parachloro-
through lateral communications/coronal access. It also phenol (CPC)
suppresses pain and facilitates apical healing.
iv. Metacresyl acetate (cresatin)
Ideal Requirements v. Creosote (beechwood creosote)
The ideal requirements of a root canal medicament are: 3. Aldehydes
• Able to kill root canal bacteria i. Formocresol (formaldehyde)
• Have long-duration of action ii. Glutaraldehyde
• Help degrade residual organic tissue and microbial 4. Halides
biofilm i. Sodium hypochlorite (chlorine)
• Easily placed and removed ii. Iodine-potassium iodide (iodine)
• Radiopaque
5. Calcium hydroxide
• Should not stain the tooth
6. Antibiotics, steroids and their combinations
• Able to induce regeneration of periapical tissue
• Not get inactivated in the presence of organic material 7. Bioactive glass
• Be inexpensive and easily available 8. Phytomedicines.
• Should not irritate periapical tissue or have systemic
1. Essential Oils
toxicity
• Have anodyne properties i. Eugenol: This is the chemical essence of oil of clove
• Induce hard tissue formation. with mild antiseptic and anodyne properties. It is
used as pulp cavity dressing after removal of non-
Functions infected vital pulp and also aids in anesthetising
The functions of intracanal medicaments are severed pulp remnants (Fig. 18.16).
categorized as: 2. Phenol Based Agents
1. Primary
i. Phenol/Methylphenol (cresol)/thymol: This is a
• Antisepsis
protoplasm poison and a potent antimicrobial
• Disinfection agent. Liquefied phenol is made by addition of one
2. Secondary part of water to 109 parts of phenol crystals. It is
• Pain control indicated where sensitive tissue remains in the canal

18
• Exudation control during instrumentation. Both cresol and thymol
• Resorption control (derivatives of phenol) are equally effective intra-
• Hard tissue formation. canal medicament.

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 Root Canal Irrigants and Medicaments 309

4. Halides
Halides consist of chlorine and iodine which are used
in various formulations in endodontics. They are potent
oxidising agents with rapid bactericidal effects.
i. Sodium hypochlorite: Chlorine, an active compo-
nent of sodium hypochlorite is used as antiseptic.
ii. Iodine-potassium iodide: Iodine is used as iodine-
potassium iodide and iodophors that release iodine
continuously. This medicament is made by mixing
4.0 gm potassium iodide with 2.0 gm iodine and
94 ml water. The main disadvantages are allergic
responses and tooth staining.

5. Calcium Hydroxide
Calcium hydroxide has gained wide popularity and
Fig. 18.16 Eugenol/pyrocresol
acceptance as intracanal medicament (Fig. 18.17). It is
effective against most root canal pathogens and has the
ii. Camphorated monochlorophenol (CMCP): CMCP
ability to degrade residual organic tissue. Its use in
is prepared by mixing 2 parts PCP and 3 parts of
endodontics relates mainly to its antibacterial property,
camphor. Camphor is added to reduce irritating
ability to induce repair and stimulate hard tissue
effect of parachlorophenol and to prolong the
formation. The bactericidal nature of calcium hydroxide
antibacterial action. It is more powerful bactericidal
is attributed to its high pH (range of 10–12). Calcium
agent than phenol and is most toxic.
hydroxide acts by releasing hydroxyl ions, which
iii. Parachlorophenol (PCP): One percent aqueous destroy bacteria by damaging cytoplasmic membrane
form of PCP is most commonly used and is found and bacterial DNA.
to be more penetrating into dentinal tubules than Calcium hydroxide, to be used as intracanal
camphorated parachlorophenol (CPC). medicament, can be either in powder or paste forms.
iv. Metacresyl acetate (cresatin): This is a clear liquid Powder form is mixed with distilled water, saline,
derivative of metacresol with low surface tension. polyethylene glycol, propylene glycol, etc. The vehicle
It is non-irritating and exhibits anodyne and used to mix calcium hydroxide and the manner in
sedative properties. which it is dispensed plays a vital role in achieving
v. Creosote (Beechwood Creosote): Beechwood maximum antibacterial effects. The paste form
creosote is a potent antibacterial and antifungal (hypocal, multical, reogan, etc.) can be easily dispensed
agent. The allergic reactions to beechwood creosote, in the root canal space and can be retrieved during
though rare, should also be taken care of during its obturation.
endodontic use. The use of beechwood creosote is
not preferred in pregnant/breastfeeding women.

3. Aldehydes
Formaldehyde, paraformaldehyde and glutaraldehyde
have been widely used in dentistry including endo-
dontics. These are water soluble, protein denaturing
agents and are most potent disinfectants.
i. Formocresol: Formocresol contains 19% formal-
dehyde and 35% cresol, dissolved in 46% water and
glycerine. It is mainly used in pulpotomy proce-
dures. The main disadvantages include toxicity,
mutagenicity and carcinogenicity.
Paraformaldehyde is the polymer form of formal-

18
dehyde, a constituent of N2 and endomethasone.
ii. Glutaraldehyde: Glutaraldehyde is also a strong dis-
infectant and fixative. 2.0% is most commonly used. Fig. 18.17 Calcium hydroxide: Powder and paste form

t.me/Dr_Mouayyad_AlbtousH
 310 Essentials of Endodontics

Calcium hydroxide has been shown to be ineffective of diffusing through dentinal tubules to reach
against Candida spp. and Enterococcus faecalis, cementum and periradicular tissues. Ledermix is
commonly associated with root canal failures. To water soluble and can be rinsed off easily.
improve the ability to disinfect and to penetrate more • Septomixine forte paste: Septomixine forte paste
deep into dentinal tubules against these organisms, contains neomycin sulphate, dexamethasone
Calcium hydroxide is combined with CMCP, cortico- polymyxin B and tyrothricin. It is not recommended
steroids and antibiotics. because of inactivity of ingredients against
Calcium hydroxide is mainly used for closure of root endodontic microorganisms.
apex, root perforations, resorptions, management of • Odontopaste: Odontopaste contains clindamycin
large periapical lesions and weeping canals. hydrochloride, triamcinolone in zinc oxide base. The
The placement of calcium hydroxide is usually a paste is effective against most of the endodontic
matter of personal preference. The commercially microorganisms and also alleviate inflammation.
available pastes may be applied with files or paper Addition of calcium hydroxide led to poor quality
points, but the material is unlikely to reach all aspects paste as steroid present gets destroyed by high
of root canal system. Spiral fillers or ultrasonically alkalinity of calcium hydroxide.
activated files are the most effective means of placement • Doxypaste: Doxypaste contains doxycycline hyclate
of calcium hydroxide in root canal. and triamcinolone in polyethylene glycol base
(doxycycline is more active and effective than
Removal and replacement: Calcium hydroxide is demeclocycline).
easily removed by washing and irrigating with water • Triple antibiotic paste: A combination of antibiotics
or sodium hypochlorite. Ultrasonically activated file is decreases the likelihood of developing resistant
also used to remove calcium hydroxide dressings. strains. The most promising and commonly used
Calcium hydroxide mixed with oil-based vehicle can combination of intracanal medicament consist of
be removed by using a chelating agent or acid (EDTA metronidazole, ciprofloxacin and minocycline. A few
or maleic acid). authors have added rifampicin to improve upon the
The duration of dressing is dependent upon the antibacterial effect. The antibiotic paste in combina-
objective of dressing. A week is sufficient if routine tion is effective in eradicating microorganisms from
antibacterial dressing is used. In cases of weeping canals the root canals; whereas, none of single antibiotic
dressing with stiff paste or only powder is necessary result in complete elimination of endodontic
for a period of 2 weeks. To induce calcific repair at the microbes. Similar combination of erythromycin,
periapex, dressing is changed every 2 weeks to evaluate metronidazole and ciprofloxacin has also been tried.
for the loss or contamination of calcium hydroxide. The • Double antibiotic paste: A combination of clindamycin
dressing may then be left in place and healing is and metronidazole in ethylene acetate base has also
assessed at 3–4 month interval. shown promising results, significantly reducing
bacterial load inside the root canal system including
6. Antibiotics, Corticosteroids and their Combinations
dentinal tubules.
Topical application of antibiotics in the root canal
The development of bacterial resistant strains,
therapy has been popular as they are active in the
allergic reactions and possible sensitization make the
presence of tissue fluids; do not stain the tooth and
virtually non-irritant to tissue cells. As there is no single antibiotic paste to be used with caution as intracanal
antibiotic effective against all microorganisms present medicament.
in the root canals, a combination of antibiotics is used Steroids have been used during root canal therapy
in the form of paste. The earlier used intracanal mainly for pain relief. The main disadvantage of steroids
antibiotics, sulphonamides, are no longer in use, as they is their depressive effect on the defence mechanism.
tend to discolor the teeth. The most commonly used
antibiotic includes combination of penicillin, bacitracin, 7. Bioactive Glass (BAG)
sodium caprylate and nystatin (PBSC/PBSCN). Bioactive glass contains oxides of calcium, sodium,
The combination of antibiotics and steroids are being phosphorous and silicone in a proportion that provides
widely used as intracanal medicament in a paste form; the material with surface activity and with a property
the commonly used are: to form a bond with mineralized hard tissues such as

18 • Ledermix paste: Ledermix paste contains demeclo-

cycline HCl, corticosteroid and triamcinolone in a
polyethylene glycol base. The ingredients are capable
bone or dentin. BAG decreases bacterial viability of
several gram-positive facultative bacteria, such as
E. faecalis, S. sanguis, S. mutans, P. aeruginon and

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 Root Canal Irrigants and Medicaments 311

C. albicans; also act against gram-negative species, such flow in the root canal using different needle types by an
as, Actinobacillus, Actinomycetemcomitans and P. unsteady computational fluid dynamics model. J. Endod.
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12. Calt S and Serper A. Time-dependent effects of EDTA on
8. Phytomedicines dentin structures. J. Endod.: 2002; 28:17–19.
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ments and their inability to eliminate bacteria from nano-silver particle endodontic irrigant. Clin. Cosmet.
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28. Haapasalo M, Qian W, Portenier I and Waltimo J. Effect of 47. McDonnell G and Russell AD. Antiseptics and disinfectants:
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34. Jain P and Ranjan M. Role of herbs in root canal irrigation – Sci.: 2014; 10:139–142.
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endodontic principles Part 4 : Irrigation. Dent. Update: 2016; activity of a new nanobased endodontic irrigation solution:
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Tay FR. Canal and isthmus debridement efficacy using a sonic applications of chlorhexidine in endodontics. Int. Endod. J.:
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38:1265–1268. 55. Mohammadi Z, Soltani MK and Shalavi S. An update on the
38. Kishan A and Shrestha A. Emerging technologies in root canal management of endodontic biofilms using root canal irrigants
disinfection. Pocket dentistry: 2016; 1–6. and medicaments. Iran. Endod. J.: 2014; 9:89–97.
39. Kishen, A, Shi Z, Shrestha A and Neoh KG. An investigation 56. Mohammadi Z, Soltani MK, Shalavi S and Asgary S. A review
on the antibacterial and antibiofilm efficacy of cationic of the properties and applications of ozone in endodontics:
nanoparticulates for root canal disinfection. J. Endod.: 2008; an update. Iran. Endod. J.: 2013; 8:40–43.
34:1515–1520.
57. Mohammadi Z. An update on the antibiotic-based root canal
40. Kishor N. Oral tissue complications during endodontic irrigation solutions. Iran. Endod. J.: 2008; 3:1–7.
irrigation: a literature review. NY. State Dent. J.: 2013; 37–42.
58. Moliz MT, Luque CM, Garcia ME and Baca P. Enterococcus
41. Lee J, Lorenzo D, Rawlins T and Cardo VA. Sodium faecalis Biofilms eradication by root canal irrigants. J. Endod.:
hypochlorite extrusion: an atypical case of massive soft tissue 2009; 35:711–714.
necrosis. J. Oral Maxillo. Surg.: 2011; 69:1776–1781.
59. Motta MV, Chaves MA and Stirton CG Sodium hypochlorite:
42. Lim Z, Cheng JL and Lim TW. Light activated disinfection: an
Accidental injection with report of a case. Int. Endod. J.: 2009;
alternative endodontic disinfection strategy. Aust. Dent. J.:
42:175–182.
2009; 54:108–114.
60. Mujoo T and Ballal V. Novel root canal irrigants: an endo-
43. Lotfi M, Vosoughhosseini S, Ranjkesh B, Khani S, Saghiri M
dontic experience. Int. J. Dent. Health Sci.: 2014; 1:356–366.
and Zand V. Antimicrobial efficacy of nanosilver, sodium
hypochlorite and chlorhexidine gluconate against 61. Murray PE, Farber RM, Namerow KM, Kuttler S and Godoy
Enterococcus faecalis. Afr. J. Biotech.: 2011; 10:6799–6803. FG. Evaluation of Morindacitrifolia as an endodontic irrigant.
J. Endod.: 2008; 34:66–70.
44. Mahmoud Torabinejad DM, Shahrokh Shabahang M, Aprecio
O, James DK. The antimicrobial effect of MTAD: An in vitro 62. Orstavik D. Root canal disinfection: A review of concepts
investigation. J. Endod.: 2003; 29:400–403. and recent developments. Aust Endod J.: 2003; 29:70–74.
45. Mancini M, Armellin E, Casaglia A, Cerroni L and Cianconi 63. Pagonis TC, Chen J, Fontana CR, Devalapally H, Ruggiero K,
L. A comparative study of smear layer removal and erosion Song X, Foschi F, Dunham J, Skobe Z, Yamazaki H, Kent R,
in apical intraradicular dentine with three irrigating solutions: Tanner ACR, Amiji MM and Soukos NS. Nanoparticle-based
a scanning electron microscopy evaluation. J. Endod.: 2009; endodontic antimicrobial photodynamic therapy. J. Endod.:
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Solution: A preliminary evaluation. Int. Endod. J.: 2000;
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65. Paul J. Recent trends in irrigation in endodontics. Int. J. Curr. paste and other intracanal medications against bacterial
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66. Peters LB, Wesselink PR and Moorer WR. The fate and the 82. Siqueira JF Jr and Lopes HP. Mechanisms of antimicrobial
role of bacteria left in root dentinal tubules. Int. Endod. J.: activity of calcium hydroxide: A critical review. Int Endod J:
1995; 28:95–99. 1991; 32:361–369.
67. Pitt WG. Removal of oral biofilm by sonic phenomena. Am. 83. Solovyeva AM and Dummer PMH. Cleaning effectiveness of
J. Dent.: 2005; 18:345–352. root canal irrigation with electrochemically activated anolyte
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Testarelli L and Gambarini G. New technologies to improve 33:494–504.
root canal disinfection. Braz. Dent. J.: 2016; 27:3–8. 84. Soukos NS, Chen PSY, Morris JT. Photodynamic therapy for
69. Rahimi S, Janani M, Lotfi M, Shahi S, Aghbali A, Pakdel MV, endodontic disinfection. J. Endod.: 2006; 32:979–984.
Milani AS and Ghasemi N. A review of antibacterial agents 85. Srikumar GPV, Sekhar KS and Nischith KG. Mixture
in endodontic treatment. Iran. Endod. J.: 2014; 9:161–168. tetracycline citric acid and detergent – a root canal irrigant.
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during endodontic therapy: a prospective randomized clinical synergistic effect of chlorhexidine and hydrogen peroxide
study. J. Endod.: 2012; 38:1177–1181. against Streptococcus sobrinus, Streptococcus faecalis and
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Practice: Feb. 2008; 7–15. 87. Stuart CH, Schwartz SA, Besson TJ and Owatz CB.
72. Russell S, Eddy AP, Joyce Steven Roberts, Thomas, BB and Enterococcus: its role in root canal treatment failure and
Frederick L. An in vitro evaluation of the antibacterial efficacy current concepts in retreatment. J. Endod.: 2006; 32:93–98.
of chlorine dioxide on E. faecalis in Bovine Incisors. J. Endod.: 88. Tanalp J and Gunger T. Apical extrusion of debris: a literature
2005; 31:672–675. review of an inherent occurrence during root canal treatment.
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Tay FR. Canal and isthmus debridement efficacy of the VPro 89. Tay FR, Gu L, Schoeffel GJ, Wimmer C, Susin L, Zhang K,
Endo Safe Negative-pressure irrigation technique. J. Endod.: Arun SN, Kim J, Looney SW and Pashley DH. Effect of vapour
2012; 38:1631–1634. lock on root canal debridement by using a side-vented needle
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and meta-analysis. Int. Endod. J.: 2007; 40:2–10. 90. Torabinejad M, Cho Y, Khademi AA, Bakland LK and
75. Schoeffel GJ. The EndoVac Method of endodontic irrigation Shabahang S. The effect of various concentrations of sodium
Part 2 – Efficacy. Dent. Today: 2008; 27:48–52. hypochorite on the ability of MTAD to remove the smear
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Part 3 – System Components and their interaction. Dent. 91. Vander SLM, Versluis M, Wu MK and Wasselink PR. Passive
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of irrigant needle depth in removing bioluminescent bacteria 92. Vemuri S, Kolanu SK, Pabbati RK, Penumaka R and Bolla N.
inoculated into instrumental root canals using real-time Effect of different final irrigating solutions on smear layer
imaging in vitro. Int. Endod. J.: 2005; 38:97–104. removal in apical third of root canal: a scanning electron
78. Shalan LA and Al-huwaizi HF.: Cleaning efficiency of root microscope study. J. Conserv. Dent.: 2016; 19:87–90.
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scanning electron microscopic study. Iran. J. Endod.: 2018; contemporary overview of endodontic irrigants - a review. J.
13:102–107. Dent. Appl.: 2014; 1:105–115.
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needles. J. Endod.: 2010; 36:884–889. 95. Zehnder M, Grawehr M, Hasselgren G and Waltimo T. Tissue-
80. Sikri V and Baljeet S. Irrigating root canals: Techniques, dissolution capacity and dentin-disinfecting potential of
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BPFA, Motta RHL and Bueno CES. Assessment of antibacterial 96. Zehnder M. Root canal irrigants. J. Endod.: 2006; 32:
activity of calcium hydroxide combined with chlorhexidine 389–398.

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Chapter
19
Root Canal Sealers

Three-dimensional sealing of root canal spaces has • Non-staining (should not discolor tooth)
always been the main goal of endodontic treatment. • Dimensionally stable
Such hermetic sealing ensures healing of periapical • Should be easily mixed and introduced into the root
tissues and also prevent re-infection of the root canal canal
spaces. Root canal sealers along with core material plays • Should be easily removed, if necessary
a major role in achieving the three-dimensional sealing • Insoluble in tissue fluids
both apically and coronally. • Bacteriostatic
The accepted method of obturation of prepared • Non-irritating to periapical tissues
canals employs a solid or semisolid core and a root canal
• Slow setting to ensure sufficient working time
sealer. Gutta-percha and other routinely used materials
• Preferably be absorbable when extruded into peri-
have no adhesives qualities to dentin regardless of the
apical tissues
obturation techniques used.
• Film thickness should be as minimum as possible
Root canal sealers facilitate filling the accessory root
canals, voids and irregularities of the root canal spaces; • Should not be mutagenic or carcinogenic (should not
subsequently minimizing leakage/percolation. The provoke any immune response).
hermetic sealing so achieved reduces the chances of
failure of root canal treatment. Functions
Sealers are defined as ‘the binding agents used to fill • Antimicrobial: Almost all sealers contain antibacterial
up the gap between root canal and the obturating material’. agent; provide germicidal quality.
They also fill up the irregularities, discrepancies, lateral • Binding agent: The sealer is able to form a bond
canals and accessory canals. Conventional sealers are between the filling material and the dentinal walls.
non-bonding (do not bind with the root dentin); • Filler: Facilitates filling the discrepancies between
whereas, bonded sealers have also been introduced obturating material and the canal walls.
with the desired effect of creating monoblock within • Lubricant: Act as lubricant when used in conjunction
the root canal. Bioceramic-based sealers are also being with semisolid material.
used with the aim of achieving monoblock effect and • Radiopacity: Most of the sealers are radiopaque.
also to strengthen the root structure. The quest for Radiopacity helps identifying presence of auxiliary
‘perfect sealer’ is still continuing. canals, resorptive areas, root fractures and shape of
apical foramen.
Requisite Characteristics of Root Canal Sealer • Obturating material: Sealers can be used as obturating
The requirements of an ideal root canal sealer are as materials, especially in deciduous teeth and in techni-
follows: ques, which use chemically plasticized gutta-percha.
• Should provide an excellent seal apically and
laterally BIOPHYSICAL PROPERTIES OF ROOT CANAL SEALERS
• Should have adequate flow The biophysical properties of root canal sealers are:
• Should produce adequate adhesion between filling i. Biocompatibility: The root canal sealer components
material and canal walls usually come in contact with vital tissues of apical
• Radiopaque (should be distinct in radiograph) area and also lateral foramina of the root canals,

314

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 Root Canal Sealers 315

may be directly or indirectly. The sealer should be debond the material from the substrate (dentin)].
conducive to the tissues, should not evoke any Sealing ability has been evaluated using leakage
inflammatory or immunological response (be studies. Various sealers have comparable sealing
biocompatible). Biocompatibility is defined as ‘the abilities. Bioceramic-based sealers have exhibited
ability of a material to achieve a positive host response better bonding and adaptability as compared to
during and after specific applications’. In simple other sealers. Recently introduced EndoCPM has
words, the material should not trigger any adverse significantly better bond strength as compared to
reactions, such as toxicity, allergic, inflammatory MTA-Fillapex and AH Plus.
or carcinogenicity. v. Antimicrobial property: Antimicrobial activity of root
Cytotoxicity of sealers has been evaluated using canal sealer helps eliminating residual infection that
human osteoblast cells and human periodontal might have survived the canal spaces through leak-
ligament cells. Presence of chemical agents, such age. Two properties of root canal sealers, (i) hydro-
as iodoform in certain sealers, evoke cytotoxic philicity and (ii) calcium diffusion, contribute to
response. Even zinc oxide eugenol has been the antimicrobial activity (hydrophilicity reduces
observed to evoke mild cytotoxic effect. Such the contact angle of the sealer and facilitate
toxicities are usually not of clinical significance; penetration of the sealer into the fine areas of root
might be of short duration or mild in action. canal system, enhancing antimicrobial activity;
Bioceramic-based sealers have been established as Diffusion of active calcium ions, creating alkaline
biocompatible. X-ray microanalysis of root canal pH also enhances antimicrobial activity). Most of
sealers has confirmed that calcium containing the studies have been conducted observing
sealers exhibited less toxicity than lead/ antibacterial effect on Enterococcus faecalis. Other
magnesium containing sealers (N2, RCB sealer). microbes have also been tested by various
Calcium enriched mixture (CEM) cement has investigators. Endo CPM, MTA-Angelus and
shown excellent biocompatibility (ability to release MTA-Fillapex have shown effective antimicrobial
calcium ions during setting and subsequent activity against almost all the microorganisms
binding of calcium and phosphorous to form inhabiting in the root canals. Calcium enriched
hydroxyapatite). mixture (CEM) cement has good antimicrobial and
ii. Flow: The sealer should fill the irregularities of antifungal effect; however, it is ineffective against
dentin, accessory canals, voids and difficult-to- E. faecalis.
access areas; the property of flow facilitates this Sealapex, Dycal and Apexit sealers are mildly
filling. Factors that influence flow include particle antibacterial (ineffective against Enterococcus
size, temperature, shear rate and mixing time/ faecalis). Calcium hydroxide based sealers have
technique. Most of bioceramic-based sealers exhibit been found ineffective against candida (limited
less flow rate as compared to the zinc oxide-based antibacterial action might be due to limited
sealers and even cement sealers. Flow of Apexit is diffusibility of calcium hydroxide into dentinal
comparable to AH26 and Tubliseal. tubules and also the possible buffering ions present
iii. Solubility: ADA and other such institutions have in tubules). Zinc oxide eugenol when exposed to
suggested that the solubility of a root canal sealer aqueous medium releases free eugenol by
should not exceed 3.0% by mass. Solubility is hydrolysis of zinc eugenolate; capable of inhibiting
defined as ‘the mass’s loss of a material during a period cell respiration even at low concentration, which
of immersion in water or tissue fluids’. The soluble accounts for high antibacterial effect of zinc oxide
sealer allows formation of gaps within core and eugenol as compared to calcium hydroxide.
the dentin; facilitating leakage from the periapical vi. Setting time: The setting time of root canal sealers
tissues. MTA-Fillapex and Root SP show solubility should be within limits and permit adequate
much above the accepted values (15 to 20%). The working time. Slow-setting sealers may produce
presence of crystalline silica in Endosequence BC mild inflammatory and toxic reactions. The
and MTA-Angelus make these sealers less soluble; complete setting time of root canal sealers varies
meat ADA specifications. considerably from four hours to four days. The
iv. Adhesion/Bonding: The capacity of the root canal setting time is usually affected by the presence of
sealer to adhere to the root dentin and create
bonding is the desirable property of a sealer [bond
strength is the force per unit area required to
moisture in the root dentin, which might get
affected by absorption with paper points, smear
plugs or even sclerosis of tubules. Sealapex sets in
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 316 Essentials of Endodontics

2–3 weeks in 100% relative humidity and does not V. Cements as sealers (Glass ionomer cement
set in dry environment. Calcium hydroxide Polycarboxylate cement)
containing sealers have complex setting reaction; VI. Silicone-based sealers (GuttaFlow, RoekoSeal)
outer mass becomes harder (set), and inner mass VII. Calcium hydroxide-based sealers (Apexit, Apexit-
remains soft (unset) for an extended period. plus, Sealapex, Biocalex, CRCS)
Manufacturer’s claim that MTA-Fillapex sets VIII. Bioceramic-based sealers (Endosequence BC/i
within two hours; whereas, MTA preparation sets Root SP, Proroot, EndoCPM, Fillapex).
in 24 hours. Most of the root canal sealers have
prolonged setting time.
INDIVIDUAL SEALERS
vii. Radiopacity: The root canal sealers should be
sufficiently radiopaque so as to ascertain its I. Zinc Oxide-based Sealers
extension in the periapical and other inaccessible
a. Kerr Pulp Canal Sealer (Rickert’s Sealer)
areas (radiopacity is generally achieved by adding
metal salts). The minimum radiopacity for a root Kerr pulp canal sealer (Rickert’s sealer) is available
canal sealer is based on a reference standard of in powder and liquid form (powder contained in a
3.0 mm aluminium. Sealers, especially those pellet and liquid in a proper bottle). One drop of
containing bismuth sulphate and bismuth trioxide, liquid is added to one pellet of powder (1:1 ratio) and
exhibit good radiopacity. Zinc oxide based sealers mixed with a heavy spatula until relative homogeneity
and also the bioceramic-based sealers exhibit is obtained (precipitated silver gives a granular
superior radiopacity as compared to others appearance).
(Sealapex is less radiopaque). The cement sets within 15–30 minutes and remain
viii. Ease of removal: The complete removal of sealer is inert; thus decreased inflammatory responses,
important during retreatment of any tooth. It has compared to other cements that may take 24–36 hours
been observed in many studies that during to set.
retreatment, most of the material left in root canals Composition
is the sealer. Bonded sealers usually pose difficulty
in their removal from the canal. Endosequence BC Powder Liquid
sealer has been reported to be the most difficult to Zinc oxide (34–41%) Oil of cloves (78–80%)
be removed from the root canals. Bioceramic-based Precipitated silver (25–30%) Canada balsam (20–22%)
sealers usually are not easily removed even with
Oleo resins (30–16%)
the use of solvents. It has been established that
Thymol iodide (11–22%)
removability of all sealers is almost comparable.
Various investigators have suggested that the
Advantages
removal should be accomplished with ultrasonics
• Excellent lubricating properties
in the coronal half, followed by rotary instruments
and hand files in the apical half area (judicious use • Allows working time of around 30 minutes when
of traces of chloroform has also been suggested). mixed in 1:1 ratio
• Germicidal
CLASSIFICATION • Biocompatible
• Greater bulk than any sealer (ideal for condensation
Definite classification of sealers has not been established;
techniques to fill voids, auxiliary canals and
however, for convenience, the sealers are divided into
irregularities)
following groups:
• Prostaglandin inhibition property (zinc oxide and
I. Zinc oxide based sealers (Kerr pulp canal sealer-
eugenol form zinc eugenolate, which is prostaglandin
Rickert’s sealer, Procosol silver cement, Procosol
inhibitor).
non-staining cement, Grossman’s sealer, Tubliseal,
Wach’s sealer) Disadvantage
II. Medicated zinc oxide eugenol based (Endometha- • Silver present in sealer usually stain the teeth.
sone, Riebler’s paste, Mynol, N2, Endoflas FS)
III. Resin-based sealers (AH 26, AH Plus, Diaket, b. Procosol Silver Cement

19 Hydron, EndoREZ, Fiberfill, ADSeal)

IV. Gutta-percha in organic solvents (Chloropercha,
Eucapercha)
The amount of precipitated silver was reduced and the
eugenol increased. The characteristics are same as Kerr
sealer; only working time is increased.

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 Root Canal Sealers 317

Composition

Powder Liquid
Zinc oxide (45%) Eugenol (90%)
Precipitated silver (17%) Canada balsam (10%)
Hydrogenated resin (36%)
Magnesium oxide (2.0%)

c. Procosol Non-staining (non-silver) Cement

Silver was removed from the sealer and Barium sulfate
was added for radiopacity.
a
Composition

Powder Liquid
Zinc oxide (40%) Eugenol (80%)
Staybelite resin (27%) Oil of almond (20%)
Bismuth subcarbonate (15%)
Barium sulfate (16%)

d. Grossman Sealer (Endoseal, Roth 801)

This sealer is widely used and satisfies most of the
requirements for an ideal sealer. The root canal sealer
is mixed on sterile glass slab with spatula. Two or three
drops of liquid is taken on a sterilized glass slab and b
small increments of cement powder is added slowly to
the liquid; mix is spatulated to a smooth creamy Fig. 19.1a and b Zinc oxide eugenol (Roth 801) sealer
consistency (Fig. 19.1a and b).
• Zinc eugenolate is decomposed by water through
Composition continuous loss of eugenol—thus a weak unstable
Powder Liquid compound.
• Setting time (hardens in two hours at 37°C).
Zinc oxide (40%) Eugenol (5%)
Staybelite resin (30%) Disadvantage
Bismuth subcarbonate (15%) • The coarse particle size of resin may lodge on the
Barium sulfate (15%) walls of the canal and obstruct the root canal filling
Sodium borate anhydrous (1.0%) from seating at correct level.

The consistency of mix can be tested by two methods, e. Tubli-Seal

(i) Drop test and (ii) String out test. It is a modification of Rickert’s formula to eliminate
In drop test, the mass of the cement is collected on the staining. It is available as a two paste system; base
the spatula and held edgewise. The cement should not and catalyst. The setting time is five minutes. It has good
drop off the spatula edge in less than 10–12 seconds. lubricating property (Fig. 19.2).
In string out test, the mass of the cement is touched Composition
with flat surface of the spatula and is raised up slowly
from the glass slab. The cement should string out for at Base Catalyst
least one inch without breaking. Zinc oxide (57–59%) Eugenol
Bismuth trioxide (18–21%) Polymerized resin
Advantages
Thymol iodide (3.5–5.0%) Annidalin
• Plasticity and low setting time.
• Good sealing potential and small volumetric change
on setting.
Oil + waxes (10%)
Barium sulfate (3.0–5.0%) 19

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 318 Essentials of Endodontics

Advantages
• Germicidal
• Less periapical irritation
• Light body.
Disadvantage
• Odor of liquid.
g. EndoFill
EndoFill is an improved version of Tubli-Seal. It has
been successfully tried as root canal sealer.
Composition
Powder Liquid
Zinc oxide Eugenol
Bismuth subcarbonate Hydrogenated resin
Barium sulfate Oil of almonds
Sodium borate

Advantages
Fig. 19.2 Tubli-Seal (zinc oxide eugenol sealer in paste • Ample working time
form) • Easy manipulation
• Good sealability
Advantages • Radiopaque.
• Easy to mix
Disadvantages
• Effective lubricant • Slight shrinkage upon setting
• Does not stain tooth structure • Complete removal is difficult.
• Expands after setting.
h. Nogenol
Disadvantages
Nogenol was developed to overcome the irritating
• Irritant to periapical tissues quality of eugenol. It is considerably less irritating than
• Working time is less than 30 minutes; even shorter other sealers. Nogenol expands on setting and improves
in presence of moisture its sealing efficacy with time (Fig. 19.3).
• Tendency to extrude out of root canal.
Composition
f. Wach’s Sealer
Base Catalyst
Composition Zinc oxide Resin methyl
Barium sulfate Salicylic acid
Powder Liquid
Zinc oxide (10 gm) Canada balsam (20 ml)
Tricalcium phosphate (2.0 gm) Oil of cloves (6.0 ml)
Bismuth subnitrate (3.5 gm)
Bismuth iodide (0.3 gm)
Magnesium oxide (0.5 gm)

Properties
• Medium working time.
• Minimum lubricating quality.
• Minimal periapical irritation.
• Sticky, due to the presence of Canada balsam.

19 • Increasing the thickness of the sealer lessens its

lubricating effect (indicated when there is a possi-
bility of over extension). Fig. 19.3 Nogenol sealer

t.me/Dr_Mouayyad_AlbtousH
 Root Canal Sealers 319

II. Medicated Zinc Oxide Eugenol Sealers

a. Riebler’s Paste
Composition

Powder Liquid
Zinc oxide Formaldehyde
Formaldehyde Sulfuric acid
Barium sulfate Ammonia
Phenol Glycerine

b. Mynol Cement Fig. 19.4 Endomethasone

Composition Composition

Powder Liquid Powder Liquid

Zinc oxide Eugenol Zinc oxide (100 gm) Eugenol
Iodoform Creosol Bismuth subnitrate (100 gm)
Resin Thymol Dexamethasone (0.019 gm)
Bismuth subnitrate Hydrocortisone (1.6 gm)
Thymol iodide (25 gm)
Both these sealers are usually used without core Paraformaldehyde (2.20 gm)
materials; introduced into the root canal by means of
Advantages
either a lentulospiral or some injection device.
• Radiopaque
c. N2 • Antibacterial
Two different types of N2 sealers are available: N2- • Good sealing ability.
normal (used for root filling) and N2-apical (used for
e. Endoflas FS
antiseptic medication of canal).
N2-‘universal’, a sealer containing the features of Endoflas FS is one of the most commonly used sealers
both N2-normal and N2-apical has been tried as root in clinical practice. It is zinc oxide based medicated
canal sealer. This is no longer used because of severe irrita- sealer marketed as powder and liquid (Fig. 19.5).
tion of periapical tissues and may lead to paresthesia. Composition
Composition
Powder Liquid
Property Powder Liquid Zinc oxide Eugenol
Radiopacifiers Zinc oxide (68.51 gm) Eugenol Iodoform Para chlorophenol
Lead tetroxide (12 gm) Cleumrosea Calcium hydroxide
Paraformaldehyde (4.7 gm) Cleum Barium sulfate (radiopacifier)
Lavandula
Bismuth subcarbonate
(2.60 gm)
Various studies have confirmed that Endoflas is an
Bismuth subnitrate (3.7 gm) effective sealing material, especially in cases of
Pigments Titanium dioxide (8.4 gm) —
periapical lesions, due to its medicinal properties. It is
resorbed periapically in case of extrusion with no side
Antiseptic Phenyl mercuric borate —
(0.09 gm)
effects; however, it does not resorb intraradicularly.
Advantages
d. Endomethasone • Ample setting time (35–40 minutes)
Endomethasone has been successfully tried as • Good sealing ability
obturating material in deciduous teeth. It is very • Antibacterial.
effective as root canal sealer. Endomethasone root canal
sealers may give rise to pain or discomfort after 6–8
weeks of insertion (Fig. 19.4).
Disadvantage
• May irritate periapical tissues.
19

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 320 Essentials of Endodontics

Fig. 19.6 Resin-based sealer (Resino-seal)

canal spaces filled with gap-free mass of core and sealer;

act as one unit with root dentin, improving the seal and
fracture resistance of the root). The resin-based sealers
Fig. 19.5 Endoflas FS (powder-liquid) can be applied easily and uniformly along the root canal
walls. All these sealers possess acceptable physical and
f. SPAD biological properties. Resin-based sealers (Fig. 19.6) are
either epoxy resin based or methacrylate resin based
SPAD is being used as a one visit obturating material.
(Diaket is a polyvinyl resin sealer).
It is a resorcinol formaldehyde resin supplied as a
powder and two liquids. The mix has also been used Monoblock Concept
as root canal sealer.
The term monoblock literally means a single unit.
Equal parts of two liquids are mixed with the powder.
Franklin Tay first described the concept of monoblock
The essential reaction to form the resin is between the
in Endodontics. Monoblocks created in root canal
resorcinol and the formaldehyde. The sealer is used in
spaces are classified as primary monoblock, secondary
pulpotomies of deciduous and permanent teeth.
monoblock, and tertiary monoblock depending on the
Setting time of SPAD is 24 hours. number of interfaces present between the bonding
Composition substrate and the core material (Fig. 19.7).

Powder Liquid (Clear) i. Primary monoblock: Primary monoblock has only

one interface that extends circumferentially between the
Zinc oxide (72.9 gm) Formaldehyde (57 gm)
material and the root canal wall (examples of primary
Barium sulfate (13 gm) Glycerine (13 gm)
monoblock are obturating the root canals with gutta-
Titanium dioxide (6.30 gm)
percha, without using the sealer and use of hydron
Paraformaldehyde (4.70 gm) Liquid (red)
Hydrocortisone acetate Glycerine (55 gm)
sealer alone). However, lack of sufficient strength and
(2.0 gm) stiffness as major drawback led to the development of
Calcium hydroxide (0.44 gm) Resorcinol (25 gm) secondary monoblock.
Phenyl mercuric borate Hydrochloric acid (20 gm) ii. Secondary monoblock: Secondary monoblocks are
(0.16 gm) having two circumferential interfaces, such as one
between the cement and dentin and the other between
Advantages the cement and the core material (common example is
• Radiopaque
• Good sealing ability.
Disadvantage
• May irritate periapical tissues.

III. Resin-based Sealers

After the successful use of self-adhesive material in

19 restorative dentistry, low viscosity resin based materials

are being tried as root canal sealers. These bondable
root canal sealers facilitate creating monoblock (root Fig. 19.7 Monoblock concept

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 Root Canal Sealers 321

obturation with gutta-percha and sealer, where one The formulation has been altered recently with the
interface is between gutta-percha point and sealer and removal of silver as one of the constituent to prevent
the second one between the sealer and root canal wall). tooth discoloration (Fig. 19.8). ThermaSeal, based on
Resilon, a bondable root filling material also falls in similar formulations has also been tried as root canal
this category. As resilon is applied using a methacrylate sealer.
based sealer to self-etching primer treated root dentin,
Advantages
it contains two interfaces, one between the sealer and
• Well-tolerated by periapical tissues (low toxicity).
primed dentin and the other between the sealer and
resilon; hence, categorized as secondary monoblock. • Excess material in the periodontal ligament tends to
become encapsulated.
iii. Tertiary monoblock: Tertiary monoblocks are • Effective sealing agent (good adhesive property).
having an additional third circumferential interface • Antibacterial.
between the bonding substrate and the abutment
material. Fiber posts that contain either an external Disadvantages
silicate coating or unpolymerized resin composite for • Overfilling may lead to paresthesia; partial recovery
relining root canals that are too wide or not perfectly within 1–2 years.
round for the fitting of conventional fiber posts may be • Releases formaldehyde, which can be toxic.
considered as tertiary monoblocks (example: EndoRez • Exceptionally slow setting cement (setting time is
system), in which the conventional gutta-percha cones 36–48 hours at body temperature and 5–7 days at
are coated with a proprietary resin coating). room temperature).
These monoblocks created by adhesive sealers and • Contracts slightly while hardening.
post systems have the potential to improve the quality
of seal and also to reinforce teeth. The treatment ii. AH Plus: AH Plus is a modified form of AH 26,
protocol consists of extirpating diseased pulp, dis- available as two paste system (Fig. 19.9). The sealer
infecting the root canal system and filling it with inert offers easy manipulations and color stability. The
obturating materials. However, the rigidity of root canal setting time of the sealer is 8 hours. Film thickness and
treated teeth is compromised by both endodontic solubility properties are also improved (film thickness
instrumentation and restorative intervention. In such of AH 26 is 39 μm and AH Plus is 22 μm; solubility
cases, the tooth strengthening potential of monoblocks in AH 26 is 0.5% and in AH Plus is 0.3%). Addition
assumes significant value. of calcium hydroxide in AH plus make the sealer less
viscous and increases pH. The increase in alkalinity
Resin-based sealers are either epoxy resin-based or improves antimicrobial abilities. Calcium may also
methacrylate-based sealers. enhance deposition of mineralized tissues.
TOPSeal was also introduced having similar
a. Epoxy Resin-based Sealers
formulation.
Epoxy resin-based sealers are:
i. AH 26: AH 26 is a slow setting epoxy resin, available
in powder/resin paste system. The sealer releases
formaldehyde on setting (freshly mixed sealer releases
maximum, which may continue up to 48 hours). The
setting time varies from 36 to 48 hours. AH 26 sealer
offers good adhesion to dentin, especially when smear
layer is removed.
Composition

Powder Resin paste

Bismuth oxide (60%) Bisphenol A
Hexamethylene tetra-amine Diglycidyl ether
(25%)
Silver powder (10%)
Titanium dioxide and calcium
hydroxide (5.0%)
Fig. 19.8 AH 26 (epoxy resin-based) sealer
19

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 322 Essentials of Endodontics

A modified form of Diaket is, Diaket A, which is

similar to Diaket but also contains the disinfectant
hexachlorophene.
iv. Sealer Plus: Sealer Plus is a recent addition to epoxy-
resin based sealer; considered superior to AH Plus. Main
ingredients are: Base paste (Bisphenol A/Bisphenol F
epoxy resin) and Catalyst paste (Hexmethylenetetramine).

b. Methacrylate Resin-based Sealers

Five generations of methacrylate resin-based sealers
have been introduced.
Fig. 19.9 AH Plus (epoxy resin-based) sealer The first generation sealer is hydron.
i. Hydron: Hydron is a rapid setting, hydrophilic plastic
Composition
material, used as a root canal sealer without the use of
Paste A Paste B a core.
Epoxy resin Adamantane amine It is a polymer of hydroxy ethyl methacrylate (poly
Calcium tungstate n, n-dibenzoyl-5-oxanonane-diamine HEMA), available as injectable root canal sealing material;
Zirconium oxide tcd-diamine
polymerized in situ and act as en-mass filling of root canal.
Iron oxide Silicone oil Hydron conforms to the shape of the root canal
Aerosil fumed silica
because of its plasticity. When the material comes in
Calcium hydroxide
contact with moisture, the gel absorbs water and swells.
Advantages
Advantages
• High radiopacity • Biocompatible
• Low solubility • Non-irritating
• Little shrinkage • Early adaptability to root canals
• Good tissue compatibility • Do not encourage bacterial growth
• No tendency to discolor • Easy insertion in root canal.
• No release of formaldehyde
Disadvantages
• Can be removed easily from the root canal.
• Cause severe inflammatory reaction
iii. Diaket: Diaket (polyvinyl resin) consists of a fine, • Severe leakage
pure white powder and a viscous, honey colored liquid. • Water sorption and swelling
Diaket is one of the few medicated cements, which • Less radiopaque (complicates radiographic observa-
does not contain paraformaldehyde. Diaket sealer is
tions).
frequently used to cement endosseous implant. Diaket
is known for its resistance to absorption. The use of hydron is obsolete because of the above
mentioned disadvantages.
Composition The second generation of these sealers are hydrophilic
and do not require dentin adhesive.
Powder Liquid
Zinc oxide Polyvinyl resin (copolymer of acetate, ii. EndoREZ: EndoREZ (ultradent) is a dual cured,
vinyl chloride, triethanolamine) radiopaque sealer. EndoREZ has been used with either
Bismuth phosphate Propionyl acetophenone conventional gutta-percha cones or with specific resin-
coated gutta-percha. An accelerator is now available,
Advantages which facilitate rapid cure of the sealer.
• Hardens rapidly
• Setting time is 6–8 minutes Composition
• Antibacterial Paste 1 Paste 2
• Good sealability.
Zinc oxide Urethane methacrylate resin

19 Disadvantage
• Produce inflammatory reaction, when in contact with
periapex.
Barium sulfate
pigments

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 Root Canal Sealers 323

Advantages Composition
• Penetrate dentinal walls and adapt closely to root
Powder Liquid
canal walls
Calcium hydroxide 4-META (methacrylate monomer)
• Effectively seals the canal without any leakage.
Bismuth oxychloride BisGMA
The third generation of these sealers contain self-
Silica, borosilicate glass UDMA
etching primer and dual-cure composite root canal
Barium sulfate Tertiary amine photoinitiators
sealer. Self-etching primer favours incorporating smear
layer along sealer-dentin interface.
The fifth generation of these sealers (ADSeal and
iii. FiberFill: FiberFill root canal sealer (pentron) is an Dia-Proseal) are the improved version of the fourth
example of third generation sealers. The sealer is used generation technology. These sealers possess excellent
along with primer (FibreFill Primer A and B). Equal physical properties, good biocompatibility and effecti-
drops of primer A and primer B are mixed and coated vely seals the root canals. The sealers are available in
onto the root dentin. Effective bonding is achieved with two paste system.
penetration of monomer into conditioned dentin i. ADSeal (Fig. 19.10)
surface. Composition
Composition
Paste A Paste B
Paste 1 Paste 2 Epoxy resin Polyaminobenzoate
Barium borosilicate glasses BisGMA Ethylene glycol salicylate Calcium phosphate
Barium sulfate Urethane dimethyl/methacrylate Calcium phosphate Bismuth subcarbonate
Calcium hydroxide Benzoyl peroxide Zirconium oxide Zirconium oxide
Silica Bismuth subcarbonate Calcium oxide triethanolamine

FiberFill Primer A Mixture of acetone and NTG- ii. Dia-Proseal

glymethacrylate Composition
FiberFill Primer B Mixture of acetone and poly-
methyl glycidyl dimethacrylate Paste A Paste B
Epoxy resin Calcium tungstate
The fourth generation of these sealers have Zirconium oxide Zirconium oxide
eliminated the separate etching/bonding step. Calcium hydroxide Calcium hydroxide
iv. MetaSeal and RealSeal: MetaSeal and RealSeal are
the commercially available fourth generation sealers. Both the sealers offer advantages such as:
The inclusion of 4-methacryloyloxyethyl trimellitate Advantages
anhydride (4-META) makes the sealer self-etching and
• Effectively seals the canals
hydrophilic. The sealer monomer promotes diffusion
• Good flow
into dentinal tubules and produces hybrid layer after
• Excellent biocompatibility
polymerization. These sealers are used with resilon
• Radiopaque
cones/pellets by using lateral condensation technique
• Easy to mix and manipulate
or with a carrier based resilon obturation system.
• Insoluble in tissue fluids
• MetaSeal
• Non-staining.
Composition

Powder Liquid
Silica nanofillers 4-META (methacrylate monomer)
Zirconium oxide HEMA
Hydrophilic initiators

• RealSeal: Earlier, RealSeal was named as Epiphany

sealer (now discontinued). Fig. 19.10 ADSeal (methacrylate resin-based) sealer
19

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 324 Essentials of Endodontics

IV. Gutta-percha in Organic Solvents Advantages

Gutta-percha dissolved in organic solvents (mainly • Better physical qualities
chloroform) has been used as root canal sealers. These • Bonding to dentin
sealers are no longer used because of the carcinogenic • Low surface tension.
property of the chloroform used as solvent. Further,
Disadvantages
these sealers proved ineffective in sealing the root canal.
• Cannot be removed from the root canal is case of
a. Kloroperka N-O Sealer retreatment.
• May create voids.
Composition
b. Polycarboxylate Cements
Powder Liquid
Polycarboxylate cement consists of modified zinc oxide
Canada balsam 19.6% Chloroform
powder and an aqueous solution of polyacrylic acid.
Resin 11.8%
The cement has chelating action and can bond both
Gutta-percha 19.6%
to enamel and dentin. Because of its adhesive and
Zinc oxide 49% antibacterial properties, the cement has been tried as a
root canal sealer. The modified form of polycarboxylate
The powder is mixed with liquid chloroform. The cement, adding calcium hydroxide and sodium fluoride
chloroform evaporates and may leave voids. Greater has been effectively used as sealers.
degree of leakage is associated with this sealer.
Advantages
b. Chloropercha • Bonds well to dentin
This is a mixture of gutta-percha and chloroform. The • Antibacterial property.
excessive shrinkage of the filling after evaporation of
the chloroform may lead to leakage and voids. Disadvantages
Chloropercha sealer is useful in unusually curved • Lack of viscosity of the material does not allow
canals or canals with ledge formations. It is used in con- proper placement.
junction with well-fitted primary cone. Chloropercha • Special plastic plugger is required for insertion since
can fill accessory canals and the root canals spaces. it has great adhesiveness to steel instruments.
• Produce inferior apical seal.
c. Modified Chloropercha Methods
• Johnson Callahan method: The root canal is flooded c. Cyanoacrylate Cements
with 95% alcohol and dried with absorbent points. Cyanoacrylate cements are composite type polymers
Callahan resin chloroform solution is applied for two containing fillers that can be polymerized to hard
to three minutes. products. They have been tried as root canal sealers.
A suitable gutta-percha cone is inserted and
Advantage
compressed laterally and apically with a stirring
matrix of the plugger until the gutta-percha is • Biocompatible.
dissolved completely in the chloroform solution in Disadvantages
the root canal. • Placement difficult
• Nygaard-Ostby method: The root canal walls are coated
• Non-uniform sealing (produce voids).
with kloroperka; the primary cone is dipped in sealer
and inserted apically into the root canal.
VI. Silicone-based Sealers
V. Cements as Sealers Silicone-based sealers are mostly used as pastes in
obturating the root canals. Examples of these sealers,
a. Glass-Ionomer Cement RoekoSeal, GuttaFlow, etc. have been used as obturating
Glass-ionomer because of its adhesive quality has been materials as well as sealers.
used as root canal sealers. Ketac-Endo is the commercial
preparation. The powder-liquid mix in 1:2 ratio can be a. RoekoSeal

19 injected in the root canal. Active GP is also available,

wherein gutta-percha cones are coated with glass
ionomer cement.
RoekoSeal is supplied in two-barrel syringe (base
and catalyst). Equal quantity of base and catalyst is
squeezed out through a removable tip. The pastes are

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 Root Canal Sealers 325

canals and dentinal tubules. This new filling system

does not shrink on setting. Two variants are available:
the routine GuttaFlow (working time 10–15 minutes
and setting time 25–30 minutes); and GuttaFlow-
fast (working time 4–5 minutes and setting time
8–10 minutes).

Advantages
• Easy and quick
Fig. 19.11 RoekoSeal (silicone-based sealer) • Excellent flow properties, which allow optimum
distribution in the root canal
mixed automatically as the base and catalyst are
• Biocompatible
extruded and folded over each other (Fig. 19.11).
Silicone-based impression materials and liners are • Can be removed easily during retreatment
preferred because of low dimensional changes. Silicone- • Provides a good seal
based implants have also shown biocompatibility. • Radiopaque.
Composition
VII. Calcium Hydroxide-based Sealers
Paste 1 Paste 2
Calcium hydroxide has been used as a root canal filling
Polydimethyl siloxane Hexachloroplastinic acid (catalyst) material, or as a sealer in conjunction with solid core
Silicone oil Zirconium dioxide (radiopacity) materials.
Paraffin base oil
Calcium hydroxide powder can be mixed with
Advantages normal saline solution and used as sealer. The alkalinity
• Biocompatible of calcium hydroxide (pH 12.3–12.5) stimulates the
• Radiopaque induction of mineralized tissue.
• Slight expansion on setting. The use of calcium hydroxide is based on the
assumption that a hard structure or tissue would be
Disadvantages created at the apical foramen. Exact mechanism of
• Average flow action is not known; however, following hypothesis is
• Manipulation/insertion is difficult. proposed:
b.GuttaFlow • Free hydroxyl ion (H) provide high alkalinity, act as
antibacterial and encourages repair.
GuttaFlow is a free flowing injectable gutta-percha
obturation system. It contains gutta-percha in powder • Alkaline pH of calcium hydroxide neutralizes lactic
form (particle size less than 30 μm), polyvinyl siloxane acid from osteoclasts and prevents dissolution of
(polydimethyl siloxane), silicone oil, paraffin oil, mineralized components of teeth.
zirconium dioxide, nanosilver particles and coloring • Calcium hydroxide denatures protein in bacterial cell
agents. It is eugenol free and radiopaque. It is a self- walls and makes them less toxic.
polymerizing system, which combines the properties
• Calcium hydroxide activates alkaline phosphatase
of sealer and gutta-percha. The two components are
homogeneously mixed in a mixing capsule and then and adenosine triphosphatase, which play important
injected into root canal (Fig. 19.12). It may also fill lateral role in hard tissue formation.
• Calcium hydroxide makes the environment
conducive for healing.

a. Sealapex
It is calcium hydroxide polymeric resin root canal
sealer; available in two paste system in collapsible tubes.

19
In 100% humidity, it takes three weeks to reach a final
set. It easily sets in dry atmosphere and expands while
Fig. 19.12 GuttaFlow (silicone-based sealer) setting (Fig. 19.13).

t.me/Dr_Mouayyad_AlbtousH
 326 Essentials of Endodontics

volume. Manufacturers advocate that it is not necessary

to prepare the root canal prior to root canal filling.
Calcium oxide and water react within the tooth to form
calcium hydroxide, which ionizes to release OH ions.
These OH ions decompose necrotic pulpal tissue to
form water and carbon dioxide.

d. Iodoform Paste
Iodoform alone or in combination with zinc oxide/
calcium hydroxide has been used as a root canal sealer
with core materials (Fig. 19.14). It is available in two
Fig. 19.13 Sealapex (calcium hydroxide-based sealer) paste formulation. Iodoform paste stimulates the
periapical tissues and accelerates bone formation.
Composition
Composition
Base Catalyst
Paste 1 Paste 2
Zinc oxide Barium sulfate
Calcium hydroxide Titanium dioxide Iodoform (60 parts) Solution (40 parts)
• Parachlorophenol
Butyl benzene Resin
• Camphor
Sulfonamide Isobutyl salicylate • Menthol
Zinc stearate Aerosil R 972
Disadvantages
b. Calcibiotic Root Canal Sealer (CRCS) • Periapical irritation.
The calcibiotic root canal sealer (CRCS) is the first • Discoloration.
calcium hydroxide-based sealer. • Aqueous parachlorophenol solution may evoke mild
CRCS is a zinc oxide eugenol eucalyptol sealer to connective tissue inflammatory response (campho-
which calcium hydroxide has been added for its rated parachlorophenol is highly toxic; capable of
osteogenic effect. CRCS takes three days to set fully causing tissue necrosis).
either in dry or humid environment.
e. Endoflas
Composition
Composition
Powder Liquid
Zinc oxide Eugenol Powder Liquid
Hydrogenated resin Eucalyptol Zinc oxide Eugenol
Barium sulfate Calcium hydroxide Para-monochlorophenol
Calcium hydroxide Iodoform Barium sulfate
Bismuth subcarbonate (radiopacifier)

The difference between CRCS and Sealapex is that

CRCS consists of a powder-liquid combination; whereas,
Sealapex is in the form of two paste preparation.

c. Biocalex
Composition

Powder Liquid
Calcium oxide Glycol
Zinc oxide Water

19 Powder and liquid are mixed to form a paste. The

sealer can expand to more than 6 times its original
Fig. 19.14 Meta pex (calcium hydroxide iodofor m)
sealer

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 Root Canal Sealers 327

alumina, calcium phosphate and hydroxyapatite. On

the basis of their interaction with the surrounding living
tissues, these materials are categorized as ‘bioactive’ and
‘bioinert’. Bioactive materials (glass and calcium
phosphate) encourages growth of tissues; whereas,
bioinert materials (zirconia and alumina) produce no
or little biological effect. The bioactive materials have
also been classified as (i) degradable and (ii) non-
degradable.
The use of bioceramics as root canal sealers provide
two advantages; (i) biocompatibility with the surround-
Fig. 19.15 Endoflas ing tissues and (ii) chemical component enhance
stimulation of crystalline structure simulating tooth and
Root canal cement may be placed in the canal either bone. However, one major disadvantage is the difficulty
by lentulospiral or reamer. The spiral is turned clock- in removing these sealers after setting for retreatment
wise by either fingers or the handpiece, placing the purpose or post-preparation.
cement apically (Fig. 19.15). It is established that bioceramic root canal sealers
An overview of conventional sealers is tabulated in have excellent bonding to root dentin. The exact mecha-
Table 19.1. The advantages and disadvantages of nism is not clear; however, suggested hypothesis are:
conventional sealers are summarized in Table 19.2. • Sealer particles diffuse into the dentinal tubules
producing mechanical interlocking bonds.
VIII. Bioceramic-based Root Canal Sealers • The mineral contents of the sealers infiltrate into
Bioceramic are the ceramic materials, which have intertubular dentin after denaturing their collagen
compatibility with biological tissues; name fibers, resulting in mineralized zone at the interface.
‘Bioceramics’. Their focus is mainly on apatite agent • Calcium silicate of the sealers reacts with dentin's
(calcium phosphate), especially the hydroxyapatite. moisture and result in formation of hydroxyapatite
Bioceramic material includes bioactive glass, zirconia, along the interface.

Table 19.1 Overview of conventional sealers

Type Brand Principle components
Zinc oxide eugenol based Kerr Pulp canal sealer Zinc oxide-eugenol, colophony, bismuth salts, barium salts
(Rickert’s sealer)
ProcoSol Zinc oxide-eugenol, thymol, silver
Tubli-seal Zinc oxide-eugenol, colophony, bismuth salts, barium salts
Wach’s sealer
Medicated zinc oxide Endomethasone Zinc oxide-eugenol, paraformaldehyde
eugenol based Riebler’s paste
EndoFlas FS
Resin based sealers AH 26, AH Plus Expoxy-bis-phenol resin, adamantine
Epiphany BisGMA, UDMA and hydrophilic methacrylates
EndoRez
Acroseal Epoxy-bis-phenol resin, methenamine, enoxolone, calcium
RealSeal hydroxide
Diaket
Cements as sealers Ketac-Endo Polyalkeonate cement, modified zinc oxide, polyacrylic acid
ActivGP
Silicone based RoekoSeal Polydimethylsiloxane, silicone oil, zirconium oxide
GuttaFlow Polydimethylsiloxane, silicone oil, zirconium oxide, gutta-
percha

19
Calcium hydroxide based Sealapex Toluene salicylate, calcium oxide
Apexit, Salicylates, calcium hydroxide
Apexit Plus

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 328 Essentials of Endodontics

Table 19.2 Advantages and disadvantages of conventional sealers

Type Brand Advantages Disadvantages
Zinc oxide eugenol based Kerr Pulp canal sealer • Radiopaque • Shrink on setting
(Rickert’s sealer) • Slow setting time • May stain tooth structure
ProcoSol • Good sealability • No bonding to core material
Tubli-seal • Will absorb if extruded
Wach’s sealer
Medicated zinc oxide Endomethasone • Radiopaque • Shrink on setting
eugenol based Riebler’s paste • Slow setting time • May stain tooth structure
EndoFlas FS • Good sealability • No bonding to core material
• Antibacterial
Resin based AH 26, AH Plus • Radiopaque • May release formaldehyde
Epiphany • Slow setting time when setting
EndoRez • Good sealability
Acroseal • Adhesive to dentin; may be
RealSeal to core material
Diaket
Cements as sealers Ketac-Endo • Radiopaque • Not antibacterial
ActivGP • Bond to dentin • Difficult to remove
Silicone based RoekoSeal • Radiopaque • Expand on setting
GuttaFlow • Long working time • Inconsistent setting time
• Good sealability
• Biocompatible
Calcium hydroxide based Sealapex • Radiopaque • Soluble
Apexit, • Good sealability • May weaken dentin
Apexit Plus • Antibacterial

The bioceramic root canal sealers are classified accord- The bioceramic-based sealers and their chemical
ing to their major constituent as (a) calcium phosphate- components are tabulated in Table 19.3. The advantages
based, (b) calcium silicate based, (c) MTA-based sealers and disadvantages of bioceramic-based sealers are
and (d) calcium enriched mixture (CEM) cement. summarized in Table 19.4.

Table 19.3 Overview of bioceramic-based sealers

Type Brand name Chemical Components
Calcium phosphate-based sealer • Sankin apatite root canal Powder: Tricalcium phosphate and hydroxyl-apatite (in Sankin
sealer (I, II and III) type I), iodoform added to powder in Type II (30%) and
type III (5%)
Liquid: Polyacrylic acid and water
• CapSeal (I and II) Powder: Tetracalcium phosphate and anhydrous dicalcium
phosphate, portland cement (gray cement in type I and white
cement in type II), zirconium oxide, etc.
Liquid: Solution of Hydroxypropyl methyl cellulose in sodium
phosphate
Calcium silicate-based sealer iRootSP/endosequence BC Zirconium oxide, dicalcium silicates, tricalcium silicate,
sealer, biodentine calcium carbonate, fillers (metal oxide)
Calcium chloride and water
MTA-based sealer • MTA-Fillapex Salicylate resin, natural resin, bismuth trioxide, nanoparticulate
silica, mineral trioxide aggregate, pigments, etc.
• Endo CPM sealer Silicon dioxide, calcium carbonate, bismuth trioxide, barium
sulfate, propylene glycol alginate, sodium citrate, calcium

19 chloride, etc.

(contd…)

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 Root Canal Sealers 329

Table 19.3 Overview of bioceramic-based sealers (contd.)

Type Brand name Chemical Components
• MTA-Angelus Tricalcium silicate, dicalcium silicate, tricalcium aluminate,
aluminium oxide, bismuth oxide, calcium carbonate,
magnesium oxide, crystalline silica, and traces of calcium
oxide, magnesium oxide, potassium/sodium sulfate
compounds
• ProRoot Endo Sealer Powder: Tricalcium silicate, dicalcium silicate, calcium sulfate,
bismuth oxide, traces of tricalcium aluminate
Liquid: Aqueous solution of a water-soluble polymer
Calcium enriched mixture (CEM) Calcium oxide, sulfur trioxide, phosphorus pentoxide,
cement silicone dioxide, traces of aluminium trioxide, sodium oxide,
magnesium oxide and water-based solution

Table 19.4 Advantages and disadvantages of bioceramic-based sealers

Type Brand name Advantages Disadvantages
Calcium phosphate-based • Sankin apatite root canal • Biocompatible • Difficult to remove
sealer sealer (I, II and III) • Radiopaque
• CapSeal (I and II) • Hydrophilic
• Antibacterial
• Do not shrink on setting

Calcium silicate-based sealer iRootSP/Endosequence BC • Biocompatible • Difficult to remove

sealer, biodentine • Radiopaque
• Hydrophilic
• Antibacterial
• Do not shrink on setting
• Excellent sealability

MTA-based sealer • MTA-Fillapex • Exhibits an alkaline pH • Removal is difficult

• Endo CPM sealer (mild antimicrobial) • Slight toxicity reported
• MTA-angelus • Good flow rate
• ProRoot Endo Sealer • Ideal working time
(35 minutes)
• Good sealability
• Easily penetrates into
accessory canals

Calcium enriched mixture • Biocompatible • Film thickness is inadequate

(CEM) cement • Short setting time (175 ± 25 μ)
• Easy manipulation • Removal is difficult
• Radiopaque
• Do not stain tooth
• Antibacterial (ineffective
against E. faecalis)
• Excellent sealability
• Ability to induce cemento-
genesis
• Slight expansion on setting 19

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 330 Essentials of Endodontics

a. Calcium Phosphate-based Sealers The biocompatible, osseoconductive hydroxyapatite

Calcium phosphate-based sealers are: has the ability to expand and harden inside the
canal, which helps to create a clinically excellent
i. Sankin Apatite Type I (Vital pulpectomy) obturation.
Composition
Composition
Powder Liquid
Powder Liquid
80% Tricalcium phosphate 25% Polyacrylic acid
Tricalcium silicate Water free-vehicle (for flow in
20% Hydroxyapatite 75% Water
paste)
ii. Sankin Apatite Type II (Infected root canals) Dicalcium silicate

Composition Calcium phosphates

Colloidal silica
Powder Liquid Calcium hydroxide
56% Tricalcium phosphate 25% Polyacrylic acid Zirconium oxide (radiopacifier)
14% Hydroxyapatite 75% Water
Advantages
30% Iodoform
• Biocompatible
iii. Sankin Apatite Type III (Partially vital)
• Excellent sealability
Composition • Non-toxic
Powder Liquid • Radiopaque.
80% Tricalcium phosphate 25% Polyacrylic acid
ii. Biodentine: Biodentine is calcium silicate-based
10 % Hydroxyapatite 75% Water
material, especially marketed as ‘dentin replacement’
5.0% Iodoform material. It has been successfully used in root perfora-
1.0% Bismuth subcarbonate tions, root resorption, retrograde filling material and
as an obturating material (Fig. 19.16). Biodentine is also
Studies revealed that Type II and Type III were
being tried as root canal sealer. Compared to other
more biocompatible probably due to the presence of
calcium based cements, this material offers two
iodoform.
advantages, (i) faster setting time (12 minutes) and
b. Calcium Silicate-based Sealers (ii) better mechanical properties. Tricalcium silicate
Calcium silicate-based sealers are: based materials are a source of forming hydroxyapatite
i. Endosequence BC Sealer/iRoot SP: Endosequence BC, when they come in contact with tissue fluids.
also known as iRoot SP, is a non-toxic calcium silicate
cement sealer. It is available as a premixed paste in a
syringe with intraoral tips for dispensing.
Endosequence BC sealer is hydrophilic and does not
set until it comes in contact with water.
When the sealer is placed in the root canal, the
material absorbs water from the dentinal tubules,
causing a hydration reaction of the dicalcium silicate
and tricalcium silicate.
Calcium phosphate reacts with calcium hydroxide
at the same time to precipitate hydroxyapatite and
water.
Hydration of the calcium silicates continues due to
absorption of water and led to the formation of a
composite network of gel-like calcium silicate hydrate,

19 which mixes with the hydroxyapatite bioceramics and

provides an impervious seal. The pH during the setting
process is alkaline (pH 12.9). Fig. 19.16 Biodentine

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 Root Canal Sealers 331

Composition

Powder Liquid
Tricalcium silicate (regulates Calcium chloride (accelerators)
setting reaction and time)
Dicalcium silicate (regulates Water hydrosoluble polymer
setting reaction and time) (water reducing agent –
plasticizer)
Calcium carbonate (filler)
Zirconium oxide (radiopacity)

Advantages
• Reduced setting time
• Better/easy manipulation
• Biocompatible
• Significantly antibacterial
• Radiopaque Fig. 19.18 ProRoot (MTA-based) sealer
• Good sealability.
When placed in the root canal, calcium and hydroxyl
c. Mineral Trioxide (MTA)-based Sealers ions are produced from the set sealer, giving rise to
Mineral trioxide (MTA)-based sealers (Fig. 19.17) are: hydroxyapatite, which aids in the formation of a
physical bond between sealer and MTA.
i. ProRoot Endo Sealer: ProRoot Endo sealer is an MTA-
based endodontic sealer, available in powder and liquid ii. Endo CPM Sealer: Endo CPM sealer effectively
form (Fig. 19.18). incorporates the physiochemical properties of root
Composition canal sealer with the biological characteristics of
MTA.
Powder Liquid
Composition
Tricalcium silicate Water soluble polymer to
improve the workability and flow Powder Liquid
Dicalcium silicate Tricalcium silicate Saline solution
Calcium sulfate (as a retarder Tricalcium oxide Calcium chloride
to increase the setting time) Tricalcium aluminate
Bismuth oxide (radiopacifier)
Tricalcium aluminate (traces) The powder consists of fine hydrophilic particles that
form a gel in the presence of moisture.
The material solidifies and forms a hard mass within
one hour.
The added advantage of Endo CPM sealer, making it
superior to other bioceramic sealers, is that it contains
calcium carbonate, which increases the release of
calcium ions and improve adhesion to the dentinal
walls.
iii. Fillapex: Fillapex, (an MTA-based sealer), is
marketed as a two paste system (Fig. 19.19).
Composition

Paste 1 Paste 2
MTA-based salicylate resin Fumed silica

Fig. 19.17 MTA-sealer

Bismuth trioxide
Fumed silica
Titanium dioxide
MTA (40%) and base resin 19

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 332 Essentials of Endodontics

phosphorous is the major component of CEM, whereas

in MTA, it may be in traces (most of the physical
properties are similar).
Calcium enriched mixture (CEM) cement has been
tried successfully in furcation region, root resorption,
root-end fillings, pulp capping, vital pulp therapy and
in regenerative endodontics.
Composition

Powder Liquid
Calcium oxide Water-based solutions
Sulfur trioxide
Phosphorus pentoxide
Silicone dioxide
Traces of aluminium trioxide,
Fig. 19.19 MTA Fillapex (MTA-based) sealer
magnesium oxide and sodium
oxide
It exhibits excellent handling characteristics and an
Advantages
improved setting time.
• Biocompatible
The salicylate reacts with calcium hydroxide and
• Short setting time
MTA within the mixture reacts with water from the
dentinal fluid. The two pastes are mixed homo- • Easy manipulation
geneously to form a rigid but semipermeable structure. • Radiopaque
• Do not stain tooth
Advantages • Antibacterial (ineffective against E. faecalis)
• Exhibits an alkaline pH (mild antimicrobial) • Excellent sealability
• Good flow rate • Ability to induce cementogenesis
• Ideal working time (35 minutes) • Slight expansion on setting.
• Good sealability
• Easily penetrates into the accessory canals. Disadvantages
• Film thickness is inadequate (175 ± 25 μ)
iv. Fluoride-doped MTA cements: Fluoride-doped MTA • Removal is difficult.
cements are recently introduced sealers.
Composition IX. Miscellaneous Sealers
a. Herbal Sealer (Biosealer)
Powder Liquid
Trees belonging to the genus Copaifera are present
White Portland cement Alphacaine SP
mainly in the Amazon Rainforest of South America.
Bismuth oxide anhydrite Sodium fluoride (retarder)
The extract of the tree leaves Copaifera langsdorffii
Sodium fluoride oleoresin is widely used as phytomedicines in Brazil.
The resin extract as liquid along with powder
The main advantage is that fluoride ions can pene- (composed of zinc oxide, calcium hydroxide, bismuth
trate into the dentin and enhance the mineralization of subcarbonate, natural resin and borax) is being tried as
the dentin. endodontic sealer. The effectiveness of the sealer has
d. Calcium enriched mixture (CEM) cement: Calcium not been documented properly.
enriched mixture (CEM) cement is considered as an
improved version of mineral trioxide. This is available b. Nanoseal Plus Sealer
in powder and liquid form. When powder is mixed with Nanoseal Plus sealer is based on nanotechnology,
water-based solution, it forms bioactive calcium and which actively seals tiny irregularities in the root canal.

19 phosphate enriched mixture. The cement releases

hydroxyl ions (OH–), which are used in the process of
hydroxyapatite production. CEM differs from MTA;
It is made of calcium phosphate hydroxyapatite
nanoparticles ranging from 40 to 60 μm. These particles
can penetrate the dentinal tubules and enter accessory

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 Root Canal Sealers 333

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Chapter
20
Obturation of
Root Canal Spaces

Success of root canal treatment depends on meticulous • No sign of apical periodontitis

cleaning and shaping of the canal system, three- • No sinus tract
dimensional sealing, and a well-fitting, ‘fluid-tight’ • No foul odor (suggests residual infection/re-
coronal restoration. The substitution of inert material infection due to anaerobes)
in the space previously occupied by the pulp tissue is • Intact temporary filling (broken/leaking fillings
technically known as obturation. Over the years, pitfalls cause re-contamination of the canal)
with one technique have led to the development of • A negative culture (preferably).
newer methods of obturation; also recognizing the fact
that no one method of obturation could satisfy all Requirements of an Ideal Obturating Material
clinical situations. It is also emphasized that no The requirements of an ideal obturating material are:
obturating technique and/or material can compensate • Can be easily introduced into the root canal
for inadequate disinfection protocol.
• Should seal the canal laterally as well as apically
Root canal obturation is defined as ‘the three-
dimensional filling of the entire root canal system as close to • Dimensionally stable
the cementodentinal junction as possible. Minimal amounts • Should be impervious to moisture
of root canal sealer, which have been demonstrated to be • Bacteriostatic
biologically compatible, are used in conjunction with the core • Radiopaque
filling material to establish an adequate seal’. • Should not stain tooth structure
• Should not irritate periradicular tissues
Aims and Objectives
• Should be easily and quickly sterilized
The aim of filling the root canal system is to prevent • Should be removed easily from the root canal, if
recontamination by microorganism, either from those necessary.
microbes left in the canal after preparation or from new
invaders from the coronal access or lateral communica-
APICAL TERMINATION OF OBTURATION
tions. The root filling should be able to destroy residual
microorganisms and adapt adequately to root canal It has been established that the position/extent of root
walls to prevent their seepage and growth. The degree canal obturation is inconsistent because of unpredict-
of seal required is dictated by the smallest molecule able anatomy at the root apex. Kutler, an early
capable of initiating and sustaining periapical inflamma- investigator, has cautioned that the cemental funnel
tion. Since, the pathogenesis of periapical lesions is a beyond the minor diameter would present difficulties
diverse phenomenon, it is wiser to achieve maximum when attempting to create hermetic sealing at that area.
seal without leaving any space between root dentin and Microanalysis of root apices have observed varied
the obturating material. shapes and irregularities in the shape of cemento-
The main objectives of obturation are to prevent per- dentinal junction. The apical constriction area is never
colation of periapical exudates into the root canal, mini- uniform at all points in a canal. The shape and contour
mizing chances of reinfection and creating a favourable of foramen also varies with age, occlusal stresses and
biological environment for the process of tissue healing. inflammatory influences. The variation in position of
these three locations (CDJ/constriction/foramen) have
When to Obturate been the cause of controversy in endodontics as regard
• Asymptomatic tooth (no pain, no tenderness) where to finish the preparation and also the extension
• No exudate/seepage (dry canal) of obturation.

335

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 336 Essentials of Endodontics

The accepted hypothesis is that the root canals should Underfilling/underextension is where gutta-percha
be filled up to the dentinocemental junction, anatomi- is short of apex.
cally demarcating periodontal tissue with the pulpal
tissues. It has been established that the dentino- Difference between overfilling and overextension
cemental junction is at an average of about 0.5 to 0.7 mm • Overfilling denotes total obturation of the root canal space
from the external surface of the apical foramen. A few with excess material extruding beyond the apical foramen.
authors prefer to fill up to the radiographic external • Overextension may also denote extrusion of the filling
surface of the root. They seek to develop a small ‘puff’ material beyond the apical foramen but with the
or ‘button’ of overfilling. The ‘puff’ or ‘button’ is impression that the canal has not been adequately filled
designed to compensate for shrinkage of the gutta- and the apex has not been sealed.
percha by pulling down tightly against the apex. It also
Preventing Overextension
facilitates dense packing of gutta-percha in the apical
area along with lateral/accessory canals, if any. • Meticulous working length control
With the use of electronic technology, the clinician • Avoid over preparation at the apical constriction
can determine the required position of the cemento- • Rotary instruments should be used with caution
dentinal junction and plan their preparation and • In case of discrepancy with gutta-percha fit and
obturation. working length, confirm again
• Plasticized gutta-percha should be used judiciously
Overfilling and Overextension • Obturation of 2-1 canal anatomy should be
Overextension and underextension of a root canal thoroughly analysed; gutta-percha in second canal
filling is a matter of its vertical dimensions; beyond or may need be adjusted.
short of apex. Overextension implies gutta-percha
extending beyond the apex (say the working length is MATERIALS USED FOR OBTURATION: CLASSIFICATION
22 mm and the gutta-percha filling at 25 mm). The A large variety of root canal filling materials have been
retrieval of overextended gutta-percha is difficult. advocated, ranging from plaster of paris, asbestos and
Overfilled canal implies well-filled root canal, but bamboo to precious metals, such as gold and platinum,
exhibiting surplus filling material past the apex (gutta- etc. However, none of the materials satisfied the
percha is well-condensed, but radiographically beyond requirements of an ideal root canal filling material.
the apex). Overjealous preparation of the apical The root canal obturating materials can be classified
constriction area may lead to overfilling. as depicted in Flowchart 20.1.
Flowchart 20.1: Classification of root canal obturating materials

20

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 Obturation of Root Canal Spaces 337

MATERIALS/TECHNIQUES OF OBTURATION d. EZfill system

1. Gutta-percha e. SmartSeal
A. Cold gutta-percha • Propoint
a. Lateral compaction method • Smart paste/Smart paste Bio
b. Modifications of lateral compaction method f. Coated cones
i. For curved canals • EndoREZ
ii. For immature apices/tubular canals • Activ GP Precision.
• Inverted point technique 4. Obturation of apical third area
• Roll-cone technique (tailor made gutta-percha a. Warm/sectional gutta-percha
roll). b. Dentin chips
B. Chemically softened gutta-percha. c. Mineral trioxide aggregate
C. Heat softened gutta-percha. d. Carrier based systems
a. Intraradicular (gutta-percha is heated within the i. SimpliFill system
canal) techniques ii. FiberFill system
i. Warm vertical condensation iii. EZFill system.
• Touch ‘n’ heat 5. Pastes as obturating materials
• System B a. N2 (Sargenti paste)
• Elements system b. Mineral trioxide aggregate
ii. Warm lateral condensation c. Calcium phosphate cement
• Endotec/Endotec II d. Calcium enriched matrix (CEM) cement
• DownPak e. Biodentine.
• Thermapact 6. Retrograde (root-end) filling materials
iii. Thermocompaction a. Amalgam
• McSpadden compactor b. Gutta-percha
• Modified McSpadden (microseal system) c. Zinc oxide eugenol/reinforced zinc oxide eugenol
• Maillefer guttacondenser compounds
• Zipperer thermocompactor/engine plugger d. Cements
• Quickfill compactor i. Polycarboxylate cement
iv. Ultrasonic plasticizing. ii. Glass ionomer cement
b. Extra-radicular (gutta-percha is heated outside the e. Composite resins
oral cavity and then placed in the root canal) f. Mineral trioxide aggregate
techniques
g. Calcium phosphate cement
i. Injectable gutta-percha
h. Bioceramic-based materials
• Obtura II/Obtura III Max
i. Biodentine.
• Calamus dual 3D system
• Ultrafil
1. GUTTA-PERCHA
• PAC-160
ii. Solid core carrier Gutta-percha was obtained from sap of the Indian
• Successfil rubber trees, indigenous to Malaysia. Now, it is
• Thermafil extracted from Palaquium trees of South America.
Gutta-percha is white in color as squeezed from the
• Densfil
trees. It is dyed to red and pink color to match the color
• Trifecta system.
of the pulp.
2. Silver cones.
Gutta-percha exists in two distinct crystalline forms,
3. Miscellaneous obturating techniques (α and β). Raw gutta-percha, as it comes directly from
a. GuttaFlow/GuttaFlow 2 the tree, is in the α-form. Once purified, as available
b. Guttacore system commercially, gutta-percha is in the β-crystalline form.
c. Resilon
• RealSeal/Realseal SE
• RealSeal one
When β-form of gutta-percha is heated, a crystalline
phase transition to the α-form takes place between 42
to 49°C.
20

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 338 Essentials of Endodontics

Composition Disadvantages
Matrix : Gutta-percha (18–22%) • Lacks rigidity (smallest standardized gutta-percha
Filler : Zinc oxide (59–67%) cones are difficult to use unless canals are enlarged
to size 25)
Radiopacifiers : Heavy metal sulfate (1–18%)
• Lacks adhesive quality (sealer has to be used)
Plasticizers : Waxes/resins/rosins (1–4%)
• Can easily be displaced under pressure (may lead to
Trace elements : (0–1.0%) overextension during condensation).
Gutta-percha is available in following forms:
i. Standardized cones correspond to ISO sizes and A. Cold Gutta-percha
0.02 taper a. Lateral Compaction Method
ii. Standardized cones with non ISO taper: 0.04, 0.06, The lateral compaction method is the most accepted
0.08, etc. and widely used method of obturation. This technique
iii. Non-standardized cones: Available in sizes extra- requires the introduction of a gutta-percha cone that
fine, fine-fine, medium-fine, fine, fine-medium, fits well to the apical preparation (master cone),
medium, medium-large, large together with a small amount of sealer. The appropriate
iv. Gutta-percha pellets/bars (for use in injectable spreader is used to compact the cone against the canal
thermoplasticized gutta-percha systems, e.g. wall. Subsequently additional cones are inserted.
Obtura)
Technique
v. Gutta-percha coated on carriers, e.g. Thermafil
• A gutta-percha cone, referred to as the ‘master cone’
vi. Medicated gutta-percha, e.g. gutta-percha containing is selected, consistent with the size of master apical
calcium hydroxide, iodoform, chlorhexidine, etc. file (Fig. 20.1).
vii. Gutta-percha powder in combination with resin, • It is checked clinically for a snug fit and ‘tug-back’.
e.g. GuttaFlow. • The apical fit of the master cone is verified by radio-
Disinfection of Gutta-percha graphs.
Though commercialized gutta-percha cones are pre- • Check for the length of the master cone; if less or
sterilized, it is advisable to disinfect them before use. more, adjust accordingly (Fig. 20.2).
gutta-percha cannot be sterilized by heat. It is dis- • Gutta-percha is notched at the level of coronal
infected by immersing in 5.25% sodium hypochlorite reference point (Fig. 20.3a), and dipped in 5.0%
for one minute and then rinsing in hydrogen peroxide/ sodium hypochlorite (Fig. 20.3b).
ethyl alcohol. Lower concentration of sodium hypochlorite • Canal is dried with absorbent paper points.
has also been tried; however, higher concentration is
preferred.
2.0% digluconate chlorhexidine is also effective in
decontaminating gutta-percha cones within five minutes.
It is documented that 10% polyvinylpyrrolidone-iodine
aqueous solution (30 seconds to one minute) and
paraformaldehyde vapors (one hour) are equally
effective in decontaminating gutta-percha cones.
Advantages
• Compactible and compressible
• Excellent adaptability to the irregularities of the
canal
• Inert
• Dimensionally stable
• Excellent tissue tolerance
• Radiopaque
• Can be easily removed from the canal, if necessary
20 • Elongability when fresh; however, turns brittle over
time.
Fig. 20.1 Master cone (selected according to master
apical file)

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 Obturation of Root Canal Spaces 339

Fig. 20.2 Checking master cone

a b
Fig. 20.3 (a) Notching of gutta-percha at coronal b
reference; (b) Notched gutta-percha dipped in 5.0% Fig. 20.4 (a) Gutta-percha coated with sealer, except at
sodium hypochlorite the apical end; (b) Cone in the canal

• The walls of the canal are coated with a thin layer of

sealer.
• The selected master cone is coated with sealer. The
apical 2.0 mm of sealer (Fig. 20.4a) is wiped out
(apical sealer may be pushed into the periapical area
during lateral compaction, as little vertical pressure
is also created). The cone is then placed in the canal
(Fig. 20.4b).
• A spreader is selected that reaches 1.0–2.0 mm apical
of the working length (Fig. 20.5).
• The selected spreader is kept there for at least 20
seconds (time needed to compact the gutta-percha).
• The spreader is disengaged from the cone by rotating
it between fingertips or when using a long handled
spreader, by rotating the handle in an arc.
• An accessory cone is inserted in the space previously
occupied by the spreader. Cones are placed parallel
to the spreader blade into the space created by the
removal of the spreader (Fig. 20.6).
• This process is repeated until the entire canal is filled
with a well-compacted gutta-percha (Fig. 20.7).
• Verify the obturation of the canal by radiograph.
Fig. 20.5 Selection Fig. 20.6 Place- Fig. 20.7 Gutta-
of spreader (2.0 mm ment of accessory percha adequa-
short of apex) cones tely condensed
20

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 340 Essentials of Endodontics

a b

c d

Fig. 20.8a to d Removal of excess gutta-percha and filling the access cavity

• Excess gutta-percha is removed from the pulp ii. For immature open apices/tubular canals: The
chamber with an instrument and temporary immature teeth, where root is not fully developed,
restoration is placed in the access cavity exhibit tubular canal and open/wide foramen. The
(Fig. 20.8a to d). apical opening is either a flaring foramen of a ‘blunder
buss’ shape. Apexification should be tried, for apical
b. Modifications of Lateral Compaction Method closure. If it fails then special methods have to be
The routinely used compaction technique is modified employed for obturation; e.g. inverted point technique
for filling curved canals and immature open apices/ and roll-cone technique (tailor-made gutta-percha
tubular canals. roll).
i. For curved canals: In case of curved canals, flexible  Inverted point technique
spreaders are used to compact the gutta-percha. The – ‘Coarse’ gutta-percha cone is selected as a primary
other features remain the same, except the master point point and the serrated butt end of the point is cut
is placed 2.0 mm short of apical terminus; since more with the scissors/scalpel.
vertical force is exerted against the primary points, as
the spreader tend to compact the gutta-percha, it may – Point is inverted and tried in the canal; should
push the gutta-percha apically. reach up to the working length and exhibit the
requisite ‘tug back’.
20 In case of severe curvatures, dilacerations, etc. lateral
compaction is not feasible; thermoplasticized gutta-
percha technique should be preferred.
– Radiograph is taken to confirm its position
(Fig. 20.9 a and b).

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 Obturation of Root Canal Spaces 341

a
Fig. 20.10 Inverted cone gutta-percha (obturated)

Fig. 20.11 Preparing gutta-percha for Roll-cone technique

b
– The master gutta-percha point is prepared by
Fig. 20.9 (a) Preoperative (open apex); (b) Confirming heating a number of gutta-percha points and
position of inverted gutta-percha cone combining them, butt to tip, until a roll has been
developed to match the size and shape of the canal
– Canal is obturated like in lateral compaction (Fig. 20. 11 ).
technique with freshly prepared cone as the – Roll is chilled with a spray of ethyl chloride or ice
primary cone (Fig. 20.10). water to stiffen it.
– This cone is tried in the canal; if still loose, more
Points to remember gutta-percha can be added.
Proper and balanced/uniform pressure is mandatory during – Gutta-percha cone so prepared is referred to as
lateral compaction. Insufficient pressure may result in poorly ‘master gutta-percha’.
condensed obturation and over pressure may lead to overfilling. – Rest of the procedure is same as for lateral
compaction method.
 Tailor-Made Gutta-percha Roll/Roll-Cone technique
B. Chemically Softened Gutta-percha
– If the apical opening is so wide that even the largest
inverted gutta-percha point is still loose in the canal,
a tailor made point must be used as a primary point.
The primary gutta-percha point is chemically softened,
which facilitate better conformation to the aberrations
20

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 342 Essentials of Endodontics

in apical canal anatomy. Chloroform, halothane and

Eucalyptol are the routinely used chemical softeners.
Earlier it was thought that chloroform is carcinogenic;
however, it has been approved by FDA and ADA for
clinical use. This is a variation of an old obturation
method called ‘Callahan-Johnston technique’, in which too
much chloroform was used (on evaporation, there was
24% decrease in volume). Now, only the tip of the point
is dipped in the solvent for one second. Sealers are
prepared by dissolving gutta-percha in these solvents,
and also resin and balsam. Such mixtures are called
‘chloropercha’ and ‘eucapercha’.
Technique
• Primary cone is blunted and fitted 2.0 mm short of
the working length.
• It is dipped in solvent for one second and kept aside
for partial evaporation of the solvent.
• Meanwhile sealer is placed in the canal. Primary cone Fig. 20.12 Preparation of Fig. 20.13 Master apical
is inserted to the working length. root canal cone
• Spreader placed for one minute to allow softened
gutta-percha to flow.
• Rest of the canal can be filled conventionally.

C. Heat Softened Gutta-percha

a. Intraradicular Techniques
(Gutta-percha is Heated within the Canal)
i. Warm vertical condensation: Schilder (1967) advocated
vertical condensation technique as an alternative to
lateral condensation. The root canals are obturated with
a maximum amount of gutta-percha and a minimum
amount of sealer. The main advantage of vertical
condensation is its ability to adapt the gutta-percha to
the irregularities of the root canal, as well as accessory
and lateral canals.
Technique a b c
• The canal is prepared, irrigated and dried (Fig. 20.12). Fig. 20.14 Selection of pluggers (a) Coronal; (b) Middle;
• A master cone is selected according to canal size and (c) Apical third
the working length. The snuggly fit of the cone is
checked radiographically. Once checked, the cone is (Fig. 20.14a to c). The smallest plugger should extend
coated with sealer and placed in the root canal to 4.0–5.0 mm coronal to the apical foramen. In the
(Fig. 20.13). coronal third, the broadest plugger is used which
• Cut-off the butt end of the cone at the incisal/occlusal does not touch the canal walls; a narrower plugger
reference point. is used for the middle third of the canal. The pluggers
• Remove the cone and cut back 0.5 to 1.0 mm of tip, are selected before try-in of the master point. The
reinsert and check the length and tug back. The cone's length is marked on these pluggers.
apical diameter should be same as the diameter of • Lightly coat all the walls with sealer.
last apical instrument. Remove the cone, keep it • Insert the cone in the canal to the working length.

20
aside. • Using a hot spoon excavator remove gutta-percha
• Three pluggers are used, that are slightly smaller cone from pulp chamber to cervical level. This
than the diameter of the root canal at different depths transfers the heat to the coronal third of the

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 Obturation of Root Canal Spaces 343

gutta-percha cone. This softened gutta-percha is

folded into a mass and compacted in an apical
direction with sustained pressure with the largest
cold plugger.
• The second heat wave begins with the introduction
of heated carrier into the gutta-percha, for 2 to
3 seconds and when retrieved, carries with it the first
selective gutta-percha removal (Fig. 20.15).
• Immediately, the mid-sized plugger is pushed into
the warm gutta-percha. The vertical pressure also
exerts lateral pressure. The filling mass is compacted
apically in 3.0 to 4.0 mm, created by repeated heat
and compaction cycles (Fig. 20.16).
• When apical 4.0–5.0 mm of gutta-percha is left, it is
again softened with heat. The narrowest plugger is
immediately inserted in the canal and the surplus Fig. 20.16 Vertically compacting gutta-percha
material along the walls is folded centrally into the
apical mass. Warmed gutta-percha is then compacted
vertically sealing portals of exit (Fig. 20.17).
• The apical filling is over. If post is to be placed, no
more gutta-percha need be used.
• ‘Back packing’ the remainder of the canal completes
the obturation. The classic method consists of
packing 5.0 mm precut segments of gutta-percha,
cold welding them to apical segment. Procedure
is continued until the entire canal is obturated
(Fig. 20.18).
• Remove excess gutta-percha and sealer from the
chamber and place temporary filling.
Advantage
Dense, homogenous obturation is achieved.

Fig. 20.17 Compacting the gutta-percha

Fig. 20.15 Heat carrier removing selective gutta-percha

Fig. 20.18 Back filling gutta-percha (either in smart parts
or with thermoplasticized technique)
20

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 344 Essentials of Endodontics

Disadvantages Disadvantages
• Technique is difficult to master. • Voids (inadequate control of the depth of insertion)
• Time consuming. • Small plugger is ineffective
• Difficult to use in curved canals where the straight,
• Plugger binding apically may split root.
rigid pluggers are unable to penetrate to the necessary
depth. To allow the rigid carriers to contact the gutta- Precautions
percha within 4.0 or 5.0 mm of the apex, the canals
• There should be a continuous tapering canal prepara-
must be prepared larger and more tapered than in
tion (diameter is narrowed apically).
the lateral compaction technique, requiring the
removal of additional dentin, which weakens the • Master cone is fitted correctly.
root. • Temperature of Touch ‘n’ heat instrument should not
• Risk of vertical root fracture because of compaction exceed 45°C.
forces. • Heated plugger should not be placed closer than
• Length control is less than lateral compaction. 4.0 to 5.0 mm of canal terminus.
• Potential for extrusion of material into the
periradicular tissues. 2. System B
‘System B’ (model 100) utilizes a digital tempera-
A slight modification of Schilder's technique, the continuous
ture display and a variable resistance control that
wave compaction technique, utilizes commercial heating devices.
allows the clinician to attain a desired temperature
The heating devices are as follows. (Fig. 20.20).
1. Touch ‘n’ heat These heat carriers are designed as pluggers that
The Touch ‘n’ heat (model 5003 and 5004) is an concentrate the heat at the tip of the carrier. The system
electronic device, especially developed for the warm B is also based on the Schilder technique. The tip of
vertical condensation of gutta-percha. It works with the plugger can be heated to 200°C; this softens the
battery and alternating current as well (Fig. 20.19). gutta-percha in half a second.
It exhibits the same thermal properties as the original
heat carrier used by Schilder but has the advantage of A wave of heat (250–300ºC) is produced as the
generating heat automatically at the tip of the instrument. plugger is forced through the already fitted cone and
The instrument is capable of providing a range of high is used to drive the gutta-percha into the canal.
temperatures instantly, ranging from 0 to 700°C. The As the plugger approaches the apex, the heat button
device may also be used for pulp testing/bleaching by is released and apical pressure is maintained with the
changing the tips and adjusting the heat level. plugger for 10 seconds. It sustains push to take up the
The heat is applied alongside the master gutta-percha shrinkage that occurs on cooling. The heat button is
using appropriate pluggers/spreaders. The canal is pushed again while maintaining pressure. A wave of
then back filled using obtura gun. heat is produced (300ºC in 5 seconds) that immediately
Advantages separates the plugger from apical mass of gutta-percha,
• Fill accessory canal facilitating rapid withdrawal of the instrument. The
• Homogenous filling canal is then backfilled with obtura.

20 Fig. 20.19 Touch ‘n’ heat Fig. 20.20 System B (cordless)

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 Obturation of Root Canal Spaces 345

Advantages
• Eliminates voids created during normal lateral
condensation of warm gutta-percha.
• Produces less heat than Touch ‘n’ heat.
Disadvantages
• Easy breakage
• Kinking of spreaders.
3. Elements system
The elements system utilizes motorized handpiece,
combining system B device and the gutta-percha
extruder. System B provides control for temperature a
and duration. The tip temperature is continuously
maintained and displayed, and the system has a time-
out option that prevents overheating.
The elements obturation technique combines two
separate machines that usually used for down pack and
backfill into one device.
The extruder (tips available in sizes 20, 23 and 25
gauge) facilitate flow of gutta-percha.
The handpieces are fitted with silicon insulator to
avoid excessive heat transferring to the clinician’s hands
during its usage (Fig. 20.21).
A case of mandibular second molar obturated with
element system is depicted in Fig. 20.22a to c. b

ii. Warm lateral condensation: Warm lateral condensa-

tion offer advantage over vertical condensation, being
able to control the obturation up to the working length.
A master cone corresponding to the working length is
coated with sealer and inserted into the canal. Various

Fig. 20.21 Elements obturation unit

Fig. 20.22 (a) Elements working length; (b) Elements master
cone; (c) Elements obturation
20

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 346 Essentials of Endodontics

devices are used to warm and condense the core 5. Endotec II

material laterally. The devices used are: It is established that warm lateral compaction with the
Endotec II increased the gutta-percha mass when
4. Endotec compared with traditional cold lateral compaction.
The ‘Endotec’ is a thermal compactor, consisting of a The instrument consists of a cordless handpiece with
cordless handpiece fitted with battery that supplies a heat/temperature control button to deliver optimum
requisite heat to the attached spreader/plugger tips. heat through its microheating tip, which can soften the
When not in use, the handpiece is kept in a battery gutta-percha (Fig. 20.23). After placing the master gutta-
charger base. percha in the root canal, Endotec II tip is inserted
Two tips are used; smaller one equivalent to size 30 2.0–4.0 mm short of working length.
file (for curved canals) and larger one equivalent to size The tip is heat activated outside the canal for 3 to 4
45 file (for routine use). The device can achieve seconds and inserted to the marked length in a
temperatures up to 350°C. circumferential rotation manner for 5 to 8 seconds; the
Procedure tip cools down and is withdrawn slowly. The procedure
• Dry the canal and apply sealer. is repeated till the entire canal is completely filled.
• Adapt master cone in the canal. 6. DownPak
• Endotec is placed in the canal to full length along- DownPak obturation device, also popular as EndoTwinn
side the gutta-percha. and Root Buddy, utilizes warm lateral condensation
• Activator button is pressed and the device is moved technique, using a combination of ultrasonic vibration
in clockwise direction. and heat.
• Release the button; the plugger cools immediately. The cordless unit has a heating and vibrating device;
• Remove the device in anticlockwise direction. can be used for both vertical and lateral obturation
• Space is created for additional gutta-percha point. (temperature and vibrations are both adjustable within
• Additional gutta-percha can be inserted if required. limits).
• Cold plugger can be used to compact the softened DownPak can be used with different materials like
gutta-percha. gutta-percha, resilon and hybrid resin filling materials
The gutta-percha compaction can be improved by having variable softening temperatures (Fig. 20.24).
using the Endotec in a ZAP and TAP method, especially A master cone is placed in the root canal in the same
in C-shaped canals of molars. manner as with lateral compaction.
ZAP: The ‘Endotec’ is preheated for 4 to 5 seconds The spreader is selected, keeping 2.0 mm short of the
before insertion along the gutta-percha point. working length. The system is vibrated and activated
TAP: The instrument is moved in and out in short
continuous strokes 10–15 times. The tip is removed from
the canal when it is still hot. Later, cold spreader is used
and accessory points are placed.
Endotec may lead to overheating and/or develop-
ment of stresses.
The internal temperature may reach up to 102°C;
since gutta-percha and dentin are poor conductors of
heat, the temperature may not cause any damage to
periodontium.
Advantages
• The obturation is superior to cold lateral compaction
method.
• Provide three-dimensional obturation.
Disadvantages
• Time consuming relative to other methods of lateral

20
compaction.
• Device tips are primarily used for heating; do not
compact the gutta-percha. Fig. 20.23 Endotec II

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 Obturation of Root Canal Spaces 347

iii. Thermocompaction: In this technique friction

between gutta-percha and the rotating “reverse file”
generates heat to soften the gutta-percha and forces it
apically. Different designs of thermocompactors are
available; the main are:
• McSpadden compactor
• Modified McSpadden (microseal system)
• Maillefer guttacondenser
• Zipperer thermocompactor/engine plugger
• Quick fill compactor
8. McSpadden compactor
McSpadden (1979) introduced an instrument,
‘McSpadden compactor’, for heat softening gutta-percha.
It resembles the reverse H-file which fits into a latch
type handpiece and rotates at 8,000–20,000 rpm. It
generates frictional heat that softens gutta-percha and
forces the material apically and laterally. As canal is
filled, the compactor is forced out coronally.
Fig. 20.24 DownPak
Disadvantages
with heat for two seconds and subsequently inserted till • Fragility of the instrument; prone to fracture.
it reaches the predetermined working length. A spreader • Cannot be used in curved canals.
is then used to condense the filling material. • Likely to overfill the canals.
Accessory cones are inserted as per need. Heat is • Difficulty in mastering the technique; manipulation
transferred to the canal after the placement of each difficult.
accessory gutta-percha cone. The vibration and heat • Frequent overheating may lead to resorption and
cause softening of the entire mass of the gutta-percha, ankylosis.
which can be condensed properly. The procedure is
repeated till the final obturation. 9. Modified McSpadden (MicroSeal system)
The combined use of heat and vibration by this system The modified McSpadden utilizes Ni-Ti condensers,
provide dense and more compact fillings than heat alone. which rotates at slower speed (1000–4000). This is also
known as MicroSeal system. It is used mainly in curved
7. Thermapact canals. (Being flexible, it is advantageous in curved
Thermapact unit consists of a transformer and an canals.) It can be used both with α-phase heat softened
electronically controlled circuit for heat generation. The gutta-percha and normal gutta-percha.
unit provides a handpiece adapted with different sized The master gutta-percha cone is placed in root canal.
spreaders and a heat carrier. The temperature can be The appropriate size condenser is selected and coated
regulated and maintained at any desired level from 40 with gutta-percha (heat softened); gutta-percha I (α)
to 70°C. or gutta-percha II (β).
It is suggested that 'Thermapact' must be maintained The condenser is then spun in the canal at 1000–4000
at 42°C for warm lateral condensation and at about rpm, which fills the gutta-percha laterally and vertically.
59° C for warm vertical condensation. The operating
temperature should be set precisely and constantly 10. Maillefer Guttacondenser
maintained. The Headstrom instrument is modified and used as
guttacondenser. The instrument has less number of
Advantages
compacting blades with deeper grooves and increased
• Warm lateral condensation effectively provides a sharpness. Guttacondenser is mainly used for back
dense and more compact obturation with a filling of canals already filled at apical third.
maximum amount of gutta-percha and a minimum
11. Zipperer thermocompactor/Engine plugger
20
amount of sealer.
• Minimal condensing pressure is required to obtain Zipperer thermocompactor resembles an inverted
a compact filling. K-file with increased number of flutes (also quoted as

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 348 Essentials of Endodontics

Engine plugger). It is used for backfilling canals already

filled at apical third and also for hybrid technique.
12. Quickfill compactor
Quickfill compactor has titanium core device
resembling latch type drills. The core is coated with α-
phase gutta-percha. The sealer is applied to the core
and is fitted to the prepared root canal. As the
instrument spins in the canal with regular low speed,
frictional heat is liberated. This heat plasticizes the
gutta-percha and it is also compacted.
After compaction, the instrument is removed and
final compaction is carried out with hand plugger. A
few authors prefer leaving the titanium core in place,
Fig. 20.25 Obtura accessories
which can be separated by appropriate burs.
iv. Ultrasonic plasticizing: Ultrasonic plasticizing can (Fig. 20.25 ). The size of silver needle is either 20 gauge
be used only in anterior teeth. A cavitron scaler with a (number 60 file) or 23 gauge (number 40 file).
PR (pull out resistant) is used for the purpose. Gutta-percha is heated approximately to 160 to
200°C. The thermoplasticized gutta-percha (temperature
Technique ranging from 62 to 65°C) extrudes from the ‘needle tip’
• Master gutta-percha is selected and placed in the root and filled in the root canals.
canal The technique is indicated mainly for curved canals
• The ultrasonic unit with the rheostat is activated for and other canal irregularities, such as root canal
3–4 seconds webbings, internal resorption, C-shaped canals and
• The energy released by vibrating motion of the accessory/lateral canals. It is also preferred for
ultrasonic file plasticizes the gutta-percha backfilling of gutta-percha.
• The file is removed and the spreader is immediately
inserted to make space for new cones Technique
• The process is repeated till obturation is completed. Sealer is necessary for this method, which facilitates
The heat produced (63.0°C) by this method is not filling the microscopic interface between the dentin
harmful. and gutta-percha and also act as a lubricant. The
The Enac Ultrasonic unit, wherein a spreader is irregularities of the canal surface are also filled with
attached is a modified version of ultrasonic plasticizing sealer, which effectively compensates for shrinkage as
unit. The spreader can penetrate the gutta-percha more the gutta-percha cools.
easily producing the requisite heat, which can plasticize Gutta-percha is preheated in the gun. The needle is
the gutta-percha. The heat generated by the unit is positioned in the canal within 3.0 to 5.0 mm of the apical
191°C, more than the required heat. preparation. The gutta-percha is passively injected into
the root canal, avoiding apical pressure. The needle is
b. Extraradicular Techniques (Gutta-percha is withdrawn slowly out of the canal as the apical portion
heated outside the Canal and then placed in is filled. Plugger dipped in alcohol is used to compact
the Canal) the gutta-percha.
i. Injectable gutta-percha: The commonly employed A segmental technique may also be used, wherein
injectable gutta-percha techniques are Obtura II and III, 3.0 to 4.0 mm segments of gutta-percha are sequentially
Calamus 3D, Ultrafil and PAC –160. injected and compacted. In either case, compaction
should continue until the gutta-percha cools and
13. Obtura II solidifies to compensate for the contraction that takes
Martin (1977) introduced Obtura and later modified it place on cooling.
to presently available Obtura II. The unit consists of an
electrical control unit, which is equipped with a digital Advantages
display of temperature and a safe circuit for controlling • The compaction of gutta-percha adaptation is

20 the temperature. Regular α-phase gutta-percha is used

with this system. A flexible silver needle is used for
delivery of plasticized gutta-percha into the root canal
significantly better than lateral compaction method.
• If the smear layer has been removed, this system may
push gutta-percha and sealer into the dentinal tubules.

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 Obturation of Root Canal Spaces 349

Disadvantages
• Potential for extrusion of gutta-percha and sealer
beyond the apical foramen.
• Heat may damage the periodontium.
14. Obtura III Max
The Obtura III Max is the modified version of Obtura
II that provides better tactile sense, ergonomics and
handling (Fig. 20.26).
A specially designed handpiece along the unit
provide the thermoplasticized gutta-percha.
An enhanced thermal protector in the system can
protect patient from thermal shocks during treatment.
The cartridge-free operation eliminates mid-
procedure filling problems. Fig. 20.27 Calamus dual 3D system

15. Calamus dual 3D system The gutta-percha has the ability to flow for 45 to
The Calamus dual 3D system provide Calamus ‘Pack’ 60 seconds, depending on the viscosity.
and Calamus ‘Flow’ handpieces. The Calamus Pack The downpacking phase implies searing off the
handpiece, an electric heat plugger, is used to thermo- gutta-percha at coronal orifice with an appropriate heat
soften, remove, and condense gutta-percha during the plugger. The plugger is used to vertically condense the
downpacking phase of obturation. The handpiece warm gutta-percha for 5 seconds.
(electrical plugger) is available in three sizes; size-based The condensation provides a three-dimensional
on apical configuration (sizes 40/03, 50/05 and 60/06 distribution of sealer; the hydraulic forces help in
and color coded as black, yellow and blue respectively). compacting the gutta-percha laterally as well as
The Calamus Pack handpiece, with its ‘thermal vertically.
response tip’ is also used for conducting ‘heat test’ on The plugger is then allowed to cool, and is removed.
the pulps (Fig. 20.27). The process is repeated till the canals are filled with
The Calamus Flow handpiece is used along with condensed gutta-percha. The coronal portion is also
disposable gutta-percha cartridge and integrated filled thereafter.
cannula (cartridges of 20 and 23 gauge size), to dispense 16. Ultrafil system
warm gutta-percha into the canal during the back-
Ultrafil system utilizes α-phase gutta-percha prepacked
packing phase of obturation. The cannula can be bent
in cannulas with attached 22 gauge needle. Gutta-percha
depending upon the curvature of root canal.
softens at a temperature of approximately 70–90°C in a
The bent cannula can pass through the coronal two- special heater. The warm cannula is placed in a special
thirds and compact the previously placed master cone. sterilizable syringe for delivery to the prepared canal.
The temperature of the thermoplasticized gutta- The gutta-percha is available in three consistencies
percha dispensed for use is around 38 to 44°C. based on its viscosity; i.e.
Regular (low viscosity) : White cannula
Firm set (moderate viscosity) : Blue cannula
Endoset (high viscosity) : Green cannula
Placement of the needle and sealer are almost similar
as in Obtura II technique. Needle placement is usually
further from the apical matrix (8–10 mm). Working time
is approximately 60–70 seconds.
For the delivery of low viscosity gutta-percha
(regular set—white cannula), the syringe trigger is
squeezed pushing a bolus of gutta-percha towards the
apical preparation. The needle is not withdrawn but is

Fig. 20.26 Obtura III Max

left in place until the mass of softened gutta-percha is
felt to lift the needle (backflow) from the canal. The
material is completely set within 30 minutes.
20

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 350 Essentials of Endodontics

Firmset (blue cannula) gutta-percha controlled • The core coated with gutta-percha is immediately
compaction can follow the injection delivery of the inserted to full depth without twisting.
material; whereas, Endoset (green cannula) gutta- • Core is severed at the coronal orifice with appropriate
percha has less flow and can be compacted with plugger bur.
and spreader. • The placement is confirmed by radiographs.
Advantages 19. Thermafil
• Better flow characteristic; broken instruments may Thermafil, an endodontic obturator, consists of a
be bypassed. flexible steel/titanium/plastic central carrier coated
• Internal resorption defects can be filled properly. with uniform α-phase gutta-percha. The size and taper
• Effective compaction is achieved. of the carrier correspond to standard endodontic files.
Plastic carriers, being flexible, are preferred. If metal
Disadvantages carrier is used, it is notched with suitable burs before
• Because of low viscosity, the material may extrude applying gutta-percha.
out of apical foramen. The carrier should preferably be heated in the oven
• Cannot be compacted; possibility of shrinkage at 115°C for 3–7 minutes depending on the size, which
(sealers cannot compensate the shrinkage). ranges from 20–140. The gutta-percha coating extends
• Restricted to cases with a substantial apical matrix beyond the carrier by 1.0–2.0 mm.
and minimal apical foramina opening. The coronal portion of the carrier has markings at
18, 19 and 20 mm and a rubber stop.
17. PAC-160 A plugger is used to apically compress the gutta-percha.
The device denotes ‘Precision apical control at 160°C’.
PAC-160 unit uses standardized gutta-percha. Definite Technique
apical constriction and coronal flare is preferred in root • The step back technique of canal preparation is
canal preparation. effective for obturation with Thermafil.
• A Thermafil obturator is selected which corresponds
Advantages to the master apical file.
• Fills accessory/lateral canal • The canal is coated with a suitable sealer.
• Irregular configurations of the root canal can be • The Thermafil obturator is heated in the oven (Oven’s
obturated uniform heat effectively plasticize the gutta-percha).
• Temperature is maintained at 160°C. • Once the gutta-percha attains a surface shine, it is
introduced into the canal with gentle pressure up to
ii. Solid core carrier: The development of gutta-percha
the working length (Fig. 20.28).
in different isomeric forms, such as α- and β-phase led
• The carrier shaft is severed at the coronal orifice
to creation of Thermafil, Successfil and Sensfil (α-phase
while applying firm pressure to the obturator handle.
gutta-percha can be heated, placed on a carrier and
The handle is removed and discarded.
delivered into the canal without an injection system).
• Placement is verified by radiographs.
18. Successfil
Successfil consists of a solid core carrier (titanium/
radiopaque plastic) coated with α-phase gutta-percha.
Gutta-percha in a warm plasticized state is added to
the carrier just before it is inserted in the canal. The
successfil syringes contain high viscosity gutta-percha
that sets in two minutes.
Technique
• The root canal is dried and the sealer is applied.
• A successfil core of the same number as the last
apical file is selected and placed up to the working
length without binding; placement checked by

20
radiograph.
• With a plugger dipped in alcohol, the gutta-percha
is compacted around the carrier. Fig. 20.28 Obturation with Thermafil

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 Obturation of Root Canal Spaces 351

Remember
While obturating posterior teeth (obturating one canal), the
other canal orifices must be sealed with damp cotton
otherwise gutta-percha may block these orifices.
Advantages
• Quick and easy.
• Can be curved to fill curved canals (with newer
flexible carriers, precurving is not required).
• Internal resorptive defects, fins, lateral canals, etc.
can be filled.
• Can be used effectively in open apices.
• Less stresses in the root because of minimal
condensation forces.
Fig. 20.29 Obturation with silver cones
Disadvantages
• Chances of extrusion Technique
• Post space preparation is difficult • Select a cone corresponding in size to the last instru-
• Removal of carriers may be difficult during ment used in the preparation of the root canal.
retreatment. • Sterilize the cone by passing through the open flame,
at least 2–3 times.
20. Densfil • Insert the cone in the canal using silver cone pliers
Densfil carriers are of two variants; plastic and titanium. or stieglitz forceps and press it apically (the cone
The plastic carrier are available in size 20 to 140 and should fit snugly and should bind at the apical
titanium carrier in size 20 to 60. Both the carriers are foramen because it corresponds to the diameter and
25 mm long. The heating is carried out in propriety taper of the prepared canal).
DensHeat oven. The techniques of placement are same
• Take a radiograph to check the fit of the cone in the
as in Thermafil. Removal is comparatively easy in case
canal. If it protrudes beyond the apex, cut-off the
of retreatment.
excess at the tip, so that final fit will terminate 0.5 mm
21. Trifecta system short of the root apex. If the silver cone is too short,
Trifecta system is the combination of both approaches, either select another one that fits or re-prepare the
Successfil and Ultrafil. A small amount (1.0–2.0 mm) canal so that the selected cone seats properly.
of α-phase Successfil gutta-percha is coated on the tip • Coat the canal with sealer and insert the sterilized
of a carrier, placed to the required depth of the canal silver cone with slight pressure to the working length.
and is slowly rotated counter-clockwise and withdrawn • Verify placement by radiographs.
from the canal. This is followed by compaction of the • Laterally condense gutta-percha cones around the
small mass of gutta-percha in the canal. The coronal primary silver cone, if need be.
position of the canal is backfilled with Ultrafil gutta-
• Excess is removed and the access cavity is filled with
percha.
temporary restoration.

2. SILVER CONES Disadvantages

Silver cones have been used as obturating material • Corrosion
despite its disadvantages. Other solid materials are used • Difficult to remove in retreatment
only as endodontic stabilizers. The use of silver cones • Poor sealing as they cannot be compacted to root
is preferred in teeth with fine and tortuous canals that canal walls (sealing is because of sealers only).
are difficult to be filled with gutta-percha (Fig. 20.29).
Silver cones are machined to correspond to the Improved Silver Points
instruments used for canal preparation. Sealer is used The silver points were improved, which have a color
along with silver cones. Gutta-percha may be laterally
condensed around the cone to ensure a proper lateral
seal.
plastic handle attached at 25 mm from the tip and has
a standardized taper (equivalent to that of the enlarging
instrument).
20

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 352 Essentials of Endodontics

Advantages over conventional silver points Technique

• Conventional silver points are inserted with pliers • The selection and verification of apical fit are carried
or a hemostat held in the operator’s hand. When these out as in conventional points.
points encounter an obstruction/curvature/any • Silver point pliers or hemostat is used to hold the
irregularity, forceful apical pressure will often cause points for twisting off. But in case of posterior teeth,
a buckling or bending of the point. With improved
either improved silver points or measurement control
silver points, the fingers can feel the tactile sense;
and a slight back and forth movement along the long- handles, should be used (also known as test handles).
axis of point facilitate by-passing the obstruction. • After determining the apical fit, the handle is
• With improved silver points, same angle of insertion attached to the point.
is utilized for point placement; whereas, the angle • Point notcher is used to partially cut and weaken
may differ with use of pliers. This is important factor the silver point at the desired position.
in treating molars, in which the angle of insertion is • The sealer is placed in the canal.
important. • Silver point is seated with gentle apical pressure.
• Since, the handles of the improved silver points are Once the correct depth is reached, the handle is
color coded; the size is recognized easily. rotated until a decrease in resistance is felt. This
Sectional or ‘Twist Off’ Silver Cone Technique indicates that the apical portion has separated.
• The apical fit is verified by radiographs.
The sectional technique is indicated wherever post and
core restoration is planned. In case of multiple rooted • The post preparation can be started in same visit as
teeth, one canal should be filled with sectional tech- the operator is familiar with the angulation and
nique, which is planned for post placement. Usually, width of the canal.
the largest canal is selected (palatal canal in maxillary The advantages and disadvantages of different
molars and distal canal in mandibular molars). obturating materials are summarized in Table 20.1.

Table 20.1 Advantages and disadvantages of different obturation methods

Method Advantages Disadvantages
Single point gutta-percha/ • Simple • Inadequate fill
Silver cones • Fast • Rely on sealers
• Inexpensive
Lateral compaction (cold) • Good for canals with irregular tapers • Sealer may create voids
• Good control of gutta-percha • Not good for irregular-shaped canals
• Fair compact obturation • Technique sensitive
Chemically softened • Good flow; fills intricacies of canals • Shrinkage; lead to leakage
gutta-percha
Warm vertical condensation • Three-dimensional obturation achieved • Technique sensitive
(Hermetic seal) • Risk of vertical root fracture
• Risk of apical extrusion
Warm lateral condensation • Three-dimensional obturation achieved • Tips used for heating do not compact
• Minimum condensation pressure required gutta-percha
Thermocompaction • Three-dimensional obturation achieved • Risk of apical extrusion
techniques • Difficulty in curved canals
• Frequent heating may lead to resorption
• Manipulation difficult
Injectable gutta-percha • Compaction is better than lateral condensation • Heat may damage periosteum
techniques • Fill intricacies of root canal • Potential for extrusion
Solid core carriers • Less stresses in root canal • Gutta-percha may strip from carrier
• Effective in open apex • Technique sensitive
• Simple and fast • Difficult to remove; post space prepara-
tion difficult
• Risk of apical extrusion

20 Apical barrier • Good apical control of material

• Bioactive
• Stimulate hard tissue formation
• Difficult to remove
• Technique sensitive

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 Obturation of Root Canal Spaces 353

3. MISCELLANEOUS OBTURATING TECHNIQUES Advantages

• Easy and quick
a. GuttaFlow/GuttaFlow 2
• Excellent flow properties
GuttaFlow is a cold free-flowing injectable gutta-percha
• Biocompatible
obturation system. It contains gutta-percha in powder
• Do not shrink
form (particle size less than 30 μm), polyvinylsiloxane
(polydimethyl siloxane), silicone oil, paraffin oil, • Can be removed easily during retreatment
zirconium dioxide, nanosilver particles and coloring • Good sealability
agents (Fig. 20.30a and b). Triturated gutta-percha is • Radiopaque.
mixed with resin sealer (polyvinylsiloxane) in an
Guttaflow 2
amalgamator to form a cold flowable matrix. The matrix
is injected into the canal (Fig. 20.30 a and b). A few GuttaFlow 2, an improved version of GuttaFlow,
authors prefer using single master cone along with contains microsilver particles (Fig. 20.31a and b).
guttaFlow. It is eugenol free, radiopaque and does not The microsilver particles provide optimum
shrink. It is a self polymerizing system, which combines protection against re-infection of the root canal. The
the properties of sealer and gutta-percha. It may also fill chemical form of silver ions does not lead to any
lateral canals and dentinal tubules. Two variants are corrosion or discoloration under clinical conditions.
available: the routine GuttaFlow has working time It is flowable, non-heated gutta-percha that does not
10–15 minutes and setting time, 25–30 minutes; whereas, shrink, but expands slightly (0.2%).
GuttaFlow (fast) has working time, 4–5 minutes and The syringe dispenses just the quantity required, which
setting time, 8–10 minutes. is homogeneously mixed (working time is 10–15 minutes).

a b
Fig. 20.30a and b GuttaFlow

a b
Fig. 20.31a and b GuttaFlow 2
20

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 354 Essentials of Endodontics

a b c
Fig. 20.32 (a) Preoperative (maxillary second premolar); (b) Working length determination; (c) GuttaFlow obturation

GuttaFlow 2 provides good adhesion to gutta-percha The selected obturator with working length marking
points and dentin walls. The combination of expansion is placed into a holder in the oven for heating (20 to
and adhesion creates an excellent seal. 25°C heat is sufficient).
It is thixotropic (viscosity diminishes under pressure); ThermaPrep ovens are available providing three-
flows into the smallest canal spaces during placement dimensional heating of obturators.
of master cone. The obturator is inserted into the root canal to the
Mostly root canal sealers are soluble in tissue fluid, working length slowly without rotation.
to a varying degree; however, the solubility of The heated gutta-percha can be condensed with a
GuttaFlow 2 is virtually zero, resulting in impervious plugger in the coronal part of the root canal.
root canal filling. The carrier is cut-off at the orifice using appropriate
GuttaFlow is extremely biocompatible. burs.
A clinical case depicting obturation with GuttaFlow Advantages
is exhibited in Fig. 20.32a to c.
• Three-dimensional obturation can be achieved
Advantages • Easy to remove during retreatment.
• Adhesion to gutta-percha point and dentin wall
• Easy to remove during retreatment and post c. Resilon
preparation The Resilon obturating system (Fig. 20.33) consists of
• Radiopaque the following components:
• Excellent sealing i. Resilon: A thermoplastic synthetic polymer
• Antibacterial (polycaprolactone) filling material (the major
• Ease of handling component); contains polymers of polyester,
bioactive glass and radiopaque filler (bismuth,
• Biocompatible.
oxychloride and bismuth sulfate).
b. GuttaCore System ii. Sealer: A dual-cure resin-based sealer that forms a
bond to the dentin wall and the core material.
The GuttaCore is a carrier-based gutta-percha obturating
system.
The obturator carriers are normally made of plastic;
whereas, GuttaCore carriers are specially designed
from a gutta-percha elastomer (does not contain
polysulfone—a routinely used component). The
obturator is made entirely of gutta-percha in two
different forms.
The core comprises of cross-linked gutta-percha and
the outer surface has alpha gutta-percha. The root canal
should be widened to at least size 20/06 or 25/04. The
right sized GuttaCore obturator is selected (working

20 length is set on the obturator).

A thin layer of sealer is applied in the prepared root
canal. Fig. 20.33 Resilon obturating system

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 Obturation of Root Canal Spaces 355

a b c
Fig. 20.34 (a) Initial access preparation; (b) Prepared root canals; (c) Postoperative (obturation)

iii. Primer: Prepares the canal wall to get in contact with sulfate, silica, calcium hydroxide, bismuth oxychloride,
Resilon and the sealer; contains HEMA, sulfonic photo initiator and pigment.
acid and water. The primer is an acidic monomer solution in water.
Resilon resembles gutta-percha and is available in The root canals are obturated with lateral or vertical
standardized (2.0% taper) and non-standardized cones; condensation technique.
and also in pellet form for use in ‘obtura’ gun (thermal RealSeal can be used in an Obtura gun as injectable
injection technique). It is also known as ‘resin-percha’, filling material and also with the elements obturation
because of accompanying sealer and the primer. system.
Various techniques (single-cone method, cold lateral
Real seal system show less microleakage than other
condensation and thermoplastic techniques) can be
resin-based obturating systems due to better bonding
employed to place Resilon in the canal, with the same
to canal walls.
instruments and devices that are used for gutta-percha
condensation (Fig. 20.34a to c). The coronal portion of RealSeal 1
the filling is light cured for 40 seconds.
RealSeal 1 is carrier-based obturating material containing
This system facilitates formation of ‘mono-block’,
a core of polysulfone coated with RealSeal Resilon
comprising of root dentin, sealer and resin-percha.
material (Fig. 20.36).
Advantages The routinely used carrier-based obturation systems
• Radiopacity better than gutta-percha use gutta-percha coating, which may not be uniform
• Less irritant than zinc oxide sealers (the gutta-percha coating can be stripped off in
• Biocompatible (non-mutagenic) constricted area of the root canal).
• Creates monoblock effect; better sealability. However, the RealSeal 1 obturator is covered with
Resilon, which does not get distorted easily (when the
RealSeal/RealSeal SE obturator encounters constriction in the canal, only the
The RealSeal system is available in two variants: the surface portion of the Resilon is affected. A thin layer
RealSeal system and the RealSeal Self-Etch (SE) system of Resilon still remains adhered to the carrier).
(Fig. 20.35).
RealSeal points are identical to Resilon obturating
points (standardized/non-standardized pellets).
RealSeal sealer contains conventional resin matrix,
silane-treated barium borosilicate glasses, barium

Fig. 20.35 RealSeal SE Fig. 20.36 RealSeal 1

20

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 356 Essentials of Endodontics

Only methacrylate resin-based sealers are preferred while being rigid enough to pass into narrower
with the system. canals.
Advantages • The outer coating is a cross-linked copolymer, which
• Reduced microleakage has been polymerized using thermal initiator. The
coating allows the point to swell laterally by
• Provide monoblock effect; better sealability
absorbing residual water from the instrumented
• Easily removed during retreatment and post space
canal space and from naturally occurring intra-
preparation.
radicular moisture. It does not swell axially, so there
d. EZ Fill System is no change in length.
EZ-Fill system consists of a bi-directional spiral filler • The lateral expansion does not cause any stress
and epoxy resin based root canal cement. The bi- and is well within tensile strength of dentin. The
directional spiral ensures uniform distribution of expansion occurs within the first 4 hours of obtura-
cement in the root canal, minimizing chances of cement tion facilitating the sealer and the polymer to produce
crossing the periapex. This controlled distribution is three-dimensional sealing.
achieved because the spirals at the coronal end spin Smartpaste/Smartpaste Bio
the cement toward the apex while the spirals at the
Smartpaste is a resin-based sealer containing an
apical end spin the cement toward the coronal end. The
active polymer that swells and fills all irregularities
area where they meet (about 3.0–4.0 mm from the apical
in the root canal. The degree of swelling is propor-
end of the shaft), the cement is thrown out laterally. A
tional to the amount of active polymer used.
prefitted single gutta-percha point is placed to the
working length. The tapered shape of the canal Smartpaste Bio is a resin-based sealer integrated with
facilitates escape of excess cement coronally. The bioceramics to make the obturation, non resorbable,
cement seals the apex and also the lateral and accessory antibacterial and biocompatible.
canals. The excess gutta-percha is seared off and the The setting time is 4–10 hours allowing sufficient
access cavity is filled with temporary restorative time for the Propoint to expand and seal the canal
materials. hermetically. The sealer is delivered in a syringe
and can be applied directly into the canal using an
Advantages intracanal tip.
• Three-dimensional filling is achieved, without any
A Propoint that matches the last file used to
lateral stress on the root
prepare the canal is selected, tried and inserted into
• Obturation is at room temperature (unlike thermo-
the canal up to the working length. The adequate
plastic techniques, there is no shrinkage upon cooling)
insertion can be confirmed by the use of radiographs.
• Radiopaque The sealer is applied inside the canal using syringe
• Flow is superior to thermoplastic gutta-percha tips. The Propoint is then introduced gently into the
• Adhesive to both dentin and gutta-percha. canal with the help of tweezers.
e. SmartSeal The extra Propoint is trimmed at the canal ori-
fice and the coronal cavity is filled with suitable
SmartSeal, a root canal obturating system, is based on material.
the hydrophilic nature of the obturating points
(polymer technology), which can absorb surrounding
f. Coated Cones
moisture and expand resulting in three-dimensional
filling of root canals. The coated cones have been developed in an attempt to
SmartSeal is a two-part system consisting of Propoint achieve similar results as those claimed by Resilon, a
and Smartpaste/Smartpaste Bio. bond between the canal wall, the core and the sealer. A
bond is formed when the resin sealer contacts the resin-
Propoint coated gutta-percha cone. This bonding minimizes the
• Propoint, also known as C Point, consists of premade leakage between the solid core and the sealer.
hydrophilic endodontic points. Two versions of coated gutta-percha are available;
• The inner core of C Point is a mix of two nylon one is EndoREZ resin-coated gutta-percha points and

20
polymers: Trogamid T and Trogamid CX. the second is ActiV GP precision, which is gutta-percha
• The polymer makes the point flexible enough, cones coated with glass-ionomer and is used with glass-
facilitating easy insertion into the curved spaces; ionomer sealer.

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 Obturation of Root Canal Spaces 357

EndoREZ The cones are available in ISO sizes 15 to 60 in either

EndoREZ is dual-cured radiopaque sealer. The sealer a 0.04 or 0.06 taper.
is coated over gutta-percha cones (sealer contains The ActiV GP Plus, a modified version has calibration
rings for easy depth measurement and a barrel
urethane methacrylate resin, zinc oxide and barium
handle for easier insertion into the canal.
sulfate). The coated points along with sealer adapt
The fit of the ActiV GP cone in the root canal is
closely to the dentinal walls, providing three-
verified using radiographs. The sealer is applied
dimensional obturation. inside the canal. The ActiV GP cone is also coated
with the sealer and slowly inserted into the canal to
ActiV GP Precision
the working length. After the ActiV GP cone has been
ActiV GP is a coated obturation material; conventional seated, the extra cone is seated off at the coronal
gutta-percha cones are coated with glass ionomer orifice. The coronal cavity is filled with suitable
sealer (Fig. 20.37). material.
The working time of the glass ionomer sealer is The advantages and disadvantages of core materials
improved by modifying its particle size to the are summarized in Table 20.2.
nanoparticle level (2.0 μm). Glass-ionomer coating
facilitates dentin adhesiveness. 4. OBTURATION OF APICAL THIRD AREA
The obturation of apical third area need special
attention, because of the interface formed between root
canal walls, obturating material/sealer on one side and
periodontium and body fluids on the other side. The
microspaces in this interface is a potential source of
microbial growth. To avoid microbial growth, a long-
term hermetic sealing is required in constantly wet
environment of the apical area. Another important
feature required is the osteoconductivity of the
obturating material and/or the sealer so as to fill the
apical area physiologically. Bioceramic-based sealers
(features as osteoconductivity, hydrophilicity,
adhesiveness and bonding to root dentin) appears to
provide effective physiological seal eliminating possible
Fig. 20.37 ActiV GP (obturation system) growth of microorganisms.

Table 20.2 Advantages and disadvantages of core materials

Core material Advantages Disadvantages
Gutta-percha • Plasticity, adapts well • Lack of adhesion to dentin
• Easy manipulation • Shrinkage, may lead to microgaps
• Non-toxic
• Radiopaque
• Ease of removal
Coated cones • Good adaptability • Life of coating, may not last longer
• Radiopaque
• Non-toxic
• Adhesion to canal wall
• Minimizes leakage
Resilon • Good adaptability • Gutta-percha coating may be stripped
• Radiopaque off in constricted areas of the root canal
• Biocompatible
• Adhesion to canal wall
• May form a monoblock
Pro-Points • Expand to fill intricacies of root canal
• Expansion does not cause any lateral stress on root dentin
• Limited documentation
20

t.me/Dr_Mouayyad_AlbtousH
 358 Essentials of Endodontics

A few authors have coined the term ‘Endodontic b. Dentin Chips

grafting’ for filling apical third areas. Obturating Dentin chips are compacted in apical third area and
material/sealer is being ‘grafted’ at the apical 3.0 mm act as ‘apical plug’ against which other materials can
area to achieve the requisite sealing. be obturated. Dentin chips create a ‘biologic seal’ rather
The obturation of only apical third area is indicated than a mechanical-chemical seal. It has been established
in certain cases, which are simultaneously restored with that dentin chips stimulate osteogenesis/cementogenesis.
post and core. The routinely used modalities are:
Technique
a. Warm/Sectional Gutta-percha • Débride and prepare the canal thoroughly.
A small section of gutta-percha is packed into apical area • Gates glidden drill/Hedstrom file is used to produce
to achieve apical obturation. The size of the sectioned dentin chips in central portion of the canal.
gutta-percha depends upon the length of root canal and • Dentin chips so produced are pushed apically with
configuration of apical foramen (Fig. 20.38 a and b). butt end of the paper point.
• 1.0–2.0 mm of chips are usually sufficient to block
Technique
the foramen (blockage checked with small size file).
• A plugger is selected which fit loosely in the root
• Apical leakage can be reduced by injecting small
canal and extend to within 3.0 mm of the working
amount of dentin adhesive into the coronal half of
length. A stopper is placed to mark the length.
the dentinal apical plug.
• Primary gutta-percha point is blunted and carried
• Rest of the canal can be filled with routine gutta-percha.
to place 1.0 mm short of working length and
confirmed radiographically. Advantages
• Upon removal, 3.0 mm of the tip (size can vary) is • Prevents overfilling
excised with scalpel. • Confines the filling materials to the canal space
• Sealer is placed in the canal. Gutta-percha tip is • Stimulate healing
warmed by passing through alcohol flame and • Minimal inflammation
carried into the canal. • Apical cementum deposition, even when the apex is
• The plugger is pressed apically and rotated counter perforated.
clockwise to separate the gutta-percha from the plugger.
Disadvantage
• Gutta-percha is thoroughly packed in the predeter-
mined apical area. Dentin chips, if infected may irritate and hinder repair.
• Radiograph is taken to confirm the placement. c. Mineral Trioxide Aggregate
• The rest of space is left to be prepared for post (paper
The placement of 4.0–5.0 mm apical barrier of mineral
point placed in the canal covered with interim filling
trioxide aggregate (MTA) has been a preferred material,
material in the coronal cavity).
especially in a canal with apical transportation. The
• Backfilling may be carried out with thermoplasticized
material offers biological compatibility, stimulating the
gutta-percha, if need be.
growth of cementum like tissue on the apical end area
(Fig. 20.39 a to d).
Technique
• A dense mix of MTA is pushed into the apical area
of the root canal with an appropriate plugger.
• Placement of material is confirmed by radiographs.
• A cotton pellet moistened in saline is placed against
the coronal aspect of the material within the canal
(periapical fluids of periapical area provide sufficient
moisture to the material).
• Rest of the canal is temporarily filled with paper
points and interim material.
• In a subsequent visit; a file is used to confirm the

20
a b hardness of the material.
Fig. 20.38 Sectional gutta-percha technique: (a) Pre- • Once the setting of material is confirmed, the
operative; (b) Gutta-percha obturation in apical half only remaining canal is managed according to the need.

t.me/Dr_Mouayyad_AlbtousH
 Obturation of Root Canal Spaces 359

• With the plug at working length, leave it thereby

turning the carrier handle counter-clockwise and
removing the carrier from the canal.
• If a post is not required, fill the remainder of the canal
by backfilling.
• If post is required, leave the apical plug intact and
prepare the post space.

Advantages
• Quick and easy
• Manipulation simple
• Does not require special equipment
a b
• Does not require heat (no guttapercha shrinkage
upon cooling)

ii. FiberFill System

The FiberFill system utilizes glass fiber post with a
terminal gutta-percha tip. The gutta-percha is available
either in 5.0 or 8.0 mm lengths. The diameter of the
post is available in sizes 30, 40, 50, 60, 70 and 80.

Technique
• An obturator is selected that matches the final
diameter of the canal.
c d
• A drop of primer is applied in the apical area with
Fig. 20.39 (a) Preoperative; (b) MTA filled in apical area; the spiral brush provided in the kit.
(c) Adjacent tooth obturated; (d) MTA filling after six
• The sealer is introduced into the canal with FiberFill
weeks
syringe.
• The obturator is gently seated to working length
d. Carrier-based Systems
allowing excess sealer to be expressed coronally.
i. SimpliFill System • The dual cure FiberFill sealer is light cured to
The SimpliFill system is designed to be compatible with stabilize the obturator.
the LightSpeed instrumentation system used for • Additional primer is applied on the protruding
cleaning and shaping the root canal. portion of the obturator post and over any dentin
The SimpliFill system utilizes a solid piece of gutta- and enamel that will be in contact with the core build-
percha (ISO size: 5.0 mm length and 0.02 mm taper) for up material.
an apical plug. The carrier for the apical gutta-percha
• A resin core build-up material in then injected
plug is made of stainless steel, which is flexible enough
around the post, filling the coronal portion of the
to negotiate curves and rigid enough to push the tight-
tooth.
fitting plug to the working length. A 1.0 mm threaded
tip holds the gutta-percha plug on the carrier, and the • The material is light cured and ready for final
carrier has a plugger-like surface, which pushed the restoration.
plug to working length.
Advantage
Technique • Provides a durable restoration with a resin/fiber
• Check the fit of the apical gutta-percha plug to the reinforced root that is optimally sealed apically and
working length. coronally.
• Place sealer in the apical part of the canal.
• After inserting the plug into the canal, slowly
advance it apically without rotating the handle.
iii. EZ Fill System
The technique has already been explained.
20

t.me/Dr_Mouayyad_AlbtousH
 360 Essentials of Endodontics

5. PASTES AS OBTURATING MATERIALS fistulation was recommended in certain cases but

Virtually all types of sealers have been tried as ‘pastes’ without raising the flap. Sargenti called it apical
in obturating root canal spaces. The purpose of the paste fenestration.
is to provide volumetrically stable filling which will It is no longer used because of following drawbacks:
adapt to the variable configuration of the root canals. • Paraformaldehyde cause toxicity, severe periapical
The paste, should not remain soft overtime and must inflammation.
set within the root canal in stipulated time so as to • May result in overextension, underextension and
provide adequate sealing. The obturating paste should voids.
be dimensionally stable, insoluble and also biocompa- • May lead to paresthesia of the nerve particularly in
tible. case of mandibular posterior teeth.
In the past, numerous obturating pastes with varying • May lead to ankylosis, root resorption.
chemical composition have been developed and tried. Presently, MTA and MTA-based cements, biodentine,
The initially tried pastes are: zinc oxide eugenol paste, calcium enriched matrix (CEM) cements are being tried
reinforced zinc oxide eugenol paste, medicated (with and investigated as root canal obturation.
paraformaldehyde and/or corticosteroids), zinc oxide
eugenol paste, calcium hydroxide alone and calcium b. Mineral Trioxide Aggregate (MTA)
hydroxide-based pastes, resin-based pastes and Mineral trioxide aggregate (MTA) has a profound
bioceramic-based pastes. Gutta-percha in paste form advantage when used as canal obturation material
and double/triple antibiotic pastes have also been used. because of its superior physiochemical and bioactive
The pastes are usually not preferred, because most properties. In addition to being sterile, radiopaque and
of the pastes are toxic when extruded out of apex. The non-shrinking, the material is not sensitive to moisture
problems of porosities, inadvertent extension and and blood contamination. MTA is not only bacterio-
difficulty in removing during retreatment are the other static, but has potential bactericidal properties. MTA
disadvantages quoted in literature. also provides an effective seal against dentin and
The obturating paste, commonly used in the past, cementum and promotes biologic repair and regenera-
though no longer used, is N2 (sargenti paste). tion of the periodontal ligament. Its unique sealing
property, combined with an initially high pH that
a. N2 (Sargenti Paste) increases to 12.5 after setting, might provide a suitable
The term N2 was coined by Sargenti to describe the environment for repair and healing. MTA in paste form
material as the second nerve. N2 filling material has has been tried as obturating the total pulp space.
red color to match the color of pulp it replaces. The
composition is as follows: Technique
• The root canal is prepared in routine and dried.
Powder • Smear layer does not affect the sealability of MTA
i. Radiopacifiers materials, and its presence may improve the seal over
• Zinc oxide (68.51 g) time. It has been speculated that the smear layer
• Lead tetra oxide (12 g) might act as a ‘coupling agent’ that might enhance
• Paraformaldehyde (4.7 g) MTA bonding to root canal dentin.
• Bismuth subcarbonate (2.60 g) • White MTA has better handling characteristics and
• Bismuth subnitrate (3.7 g) compactibility, attributed to smaller particle sizes, but
ii. Pigments grey MTA appears to have superior sealing properties.
• Titanium dioxide (8.4 g) • MTA can be mixed with 0.12% chlorhexidine (rather
iii. Antiseptic component than sterile water or anesthetic solution), which may
• Phenyl mercuric borate (0.09 g) increase its antibacterial properties.
• The mixed MTA is placed in the canal with a carrier
Liquid gun and advanced apically with an endodontic
i. Eugenol plugger.
ii. Cleum Rosea • A radiograph is taken to assess the presence of voids.
iii. Cleum Lavandula. • When the requisite density is achieved at the

20 The technique employed canal preparation with no

intracanal irrigant and filling with a N2 paste. The
whole treatment is carried out in single sitting. Artificial
periapex, fresh MTA is placed in the canal and
compacted from the apical to coronal area by using
appropriate pluggers.

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 Obturation of Root Canal Spaces 361

Advantages • A specially designed instrument/plugger is used to

• Not sensitive to moisture and blood contamination. condense the material apically. The plugger is
• Antibacterial (prevents growth of bacteria) pushed gently up and down; the end should remain
• Does not shrink in the reservoir.
• Biocompatible. • The placement of the material is kept 1.0 mm short
of the working length.
Disadvantages • The tactile feeling of ‘tightening’ of plugger is the
• Gray MTA can discolor teeth if the material is placed stage where the plugger is removed from the canal.
near the cementoenamel junction, especially in • A correct sized gutta-percha is inserted midway into
anterior teeth. the root canal (the gentle pressure will move the
• Removal is difficult after setting. material evenly along the root canal walls).
• Slow setting time (the material can take 2.5–4.0 hours • Excessive gutta-percha and the bioceramic materials
for an initial set and 21 days for complete setting). are wiped out of the coronal end.
• After setting of the material (may be 24 hours), the
c. Calcium Phosphate Cement coronal cavity is filled.
Earlier, decalcified allogenic bone matrix (DABM) and • The additional gutta-percha along with bioceramic
tricalcium phosphate (TCP) have been tried as material facilitates removal during post and core
obturating materials. Calcium phosphate cement (CPC) placement and also during retreatment.
when used as a root canal filling material has shown
positive results. 6. RETROGRADE (ROOT END) FILLING MATERIALS
Tetracalcium phosphate is the basic constituent; the Surgical intervention in root canal therapy usually
acidic component is either dicalcium phosphate involves resecting a portion of the root apex and filling
dihydrate or anhydrous dicalcium phosphate. Setting the root-end cavity with appropriate material. These
time may be extended by adding glycerine (glycerin root-end filling materials or retrograde filling materials
also helps improve its extrudability from a 19 gauge are placed in direct contact with vital periapical tissues.
needle). It is radiopaque (radiopacity is equal to bone The purpose of retrograde filling is to prevent leakage
density). of microorganisms and their byproducts from
Cement is mild irritant to periapical tissue for some periradicular tissues to root canals and from root canals
time; however, well-tolerated by tissues with passage to periradicular tissues. The materials, which stimulate
of time. Calcium phosphate cement stimulate cemento- deposition of cementum on the cut root end are being
genesis and osteogenesis within the canal. preferred as retro-filling materials. The deposition of
cementum or tissues simulating cementum/dentin
d. Calcium Enriched Matrix (CEM) Cement and provides the best biological seal.
Biodentine The retrograde (root-end) filling materials are either
Calcium enriched matrix (CEM) cement and Biodentine of rigid or plastic material (Table 20.3).
are being tried as root canal obturating materials. Requisite characteristics of root-end filling materials
Bioceramic-based sealers are also being used in root The ideal requirements of root end filling materials are:
canal obturation. • Non-toxic
• Non-carcinogenic
Capillary Condensation Method
Dr Kosser Deyan (2009) devised a technique of filling Table 20.3 Root-end filling materials
bioceramic materials in root canal and named it as Rigid materials Plastic materials
‘Capillary condensation method’.
• Gold foil • Amalgam
The steps followed in this method are: • Gallium alloy • Zinc oxide eugenol/reinforced
• Titanium inserts zinc oxide eugenol compounds
• The coronal third of root canal is conically widened
• Ceramic inserts • Cements (glass-ionomer, poly-
to form a ‘coronal reservoir’, which is to be filled • Metal inlays carboxylate)
with bioceramic materials. • Gutta-percha • Mineral trioxide aggregate
• The bioceramic-based material mixes are either • Composite resin
directly placed in the reservoir or with the use of
20
• Calcium phosphate cement
guns. The material is distributed evenly in the • Bioceramic-based materials
• Biodentine
reservoir using wet plastic carrier.

t.me/Dr_Mouayyad_AlbtousH
 362 Essentials of Endodontics

• Biocompatible • Moisture sensitive

• Dimensionally stable (presence of moisture should • Condensation is difficult from apical end.
not affect its sealing ability)
• Easy to use c. Zinc Oxide Eugenol/Reinforced Zinc Oxide
• Radiopaque Eugenol Compounds
• Should stimulate hard-tissue formation Zinc oxide eugenol and reinforced zinc oxide eugenol
• Should not be electrochemically active compounds (IRM, Super EBA Kalzinol, Cavit, etc.) have
• Non-resorbable been effectively used as root-end fillings. Super EBA and
• Antibacterial. IRM show less leakage as compared to silver amalgam.
Various materials have been tried in root-end fillings, Cavit is a reinforced zinc oxide based temporary
viz. Gold foil, silver, gallium alloys, zinc oxide eugenol, filling material. Cavit is soft when placed in the tooth
modified zinc oxide eugenol, polycarboxylate cement, and subsequently undergoes a hygroscopic set after
glass-ionomer cements, mineral trioxide aggregate and permeation with water, giving a higher linear
calcium phosphate cement. Composite resin, bio- expansion (18%). This rationalizes its use as a root-end
ceramics and a few herbal products have also been tried. filling material. These materials have excellent sealing
The commonly used retrograde filling materials are ability and are significantly biocompatible.
as follows. Disadvantages
a. Amalgam • Moisture sensitive
• Initial tissue irritation
Amalgam has extensively been used as retro-filling
material. High copper zinc-free amalgam is preferred. • Eugenol may exhibit mild toxicity
It is established that use of varnish and amalgambond • Solubility and quick disintegration in tissue fluids.
(4-META bonding agent) with amalgam significantly
improves the sealing. It is easy to manipulate and has d. Cements
good radiopacity. It is non-soluble in tissue fluids. The i. Polycarboxylate Cement
sealing improves as amalgam ages due to formation of Apical leakage studies have indicated that polycarbo-
corrosion products. xylates, when used as root-end fillings, leak signi-
Disadvantages ficantly greater than amalgam or gutta-percha. Based
• Initial marginal leakage on their poor sealing ability and uncertain periradicular
• Corrosion tissue response, the use of polycarboxylate as root-end
• Scattered silver particles are difficult to remove; not filling material is highly questionable.
get resorbed
ii. Glass-ionomer Cement
• Tin and mercury contamination of periapical tissues
• Moisture sensitivity of some alloys Glass-ionomer cement has been successfully tried as
• Cytotoxic, especially at initial stages root-end filling material. It is easy to handle and does
• Paresthesia has also been reported not cause any adverse histological reaction in the
• Need for retentive undercut preparation periapical tissue. Sealing ability of glass-ionomer is
adversely affected when the root-end cavities are
• Staining of hard and soft tissues
contaminated with moisture at the time of placement
• Technique sensitivity.
of cement. Light cure glass-ionomer cement show least
b. Gutta-percha leakage due to less moisture sensitivity, less curing
Gutta-percha filled tooth when resected at the apical shrinkage and better penetration into dentinal surface.
end, the visible gutta-percha is condensed in the root- Metal reinforced glass-ionomer have also shown better
end cavity, either by cold or hot burnisher. Thermo- results.
plasticized gutta-percha has also been filled at root end Disadvantages
cavities. Gutta-percha may absorb moisture initially • Moisture sensitive (cavity should be dry)
and expand; however, as the time passes, it contracts. • Initially cytotoxic.
Gutta-percha fillings offer better sealing than amalgam.
It is also non-resorbable and biocompatible. e. Composite Resin
20 Disadvantages
• Apical seal may get disturbed with time
Composite resins due to their cytotoxic or irritating
effects on pulp tissue have received minimal attention

t.me/Dr_Mouayyad_AlbtousH
 Obturation of Root Canal Spaces 363

as root-end filling materials. However, a few authors and, more importantly, form a chemical bond with
opined that when composite resins are properly used, dentin. They are claimed to promote cementogenesis
the cytotoxic effects are substantially decreased or and form a hermetic seal at the root end. These materials
eliminated. The proper use of dentin bonding agents are biocompatible and do not induce any cytotoxic
and composite resin may play a significant role as root- effects. Calcium aluminate silicate-based materials
end filling. (Endo binder, Generex A, etc.) have shown better results
Newer composites, Retroplast and Geristore are (calcium oxide/magnesium oxide was removed from
being tried as retrograde filling material. 30% colloidal the powder minimizing expansion and also the
silica/silver provided radiopacity in the materials. staining). The commonly used bioceramic-based
Since, colloidal silver had some disadvantages; it was materials are:
replaced with ytterbium trifluoride. The new • Capasio
combination is successful as retrofilling material. • Iron-free partially stabilized cement
Disadvantages • Endosequence/iRoot BP
• Sensitive to moisture/blood contamination • Root end cement
• Mild cytotoxicity. • Endobinder
• Generex A
f. Mineral Trioxide Aggregate • Quickset.
Mineral trioxide aggregate (MTA) primarily contain
tricalcium silicate, tricalcium aluminate, tricalcium i. Biodentine
oxide and silicate oxide. The material has been Biodentine is also being tried as root-end filling material.
successfully used as root-end filling material, offering Compared to other calcium based cements, this material
advantages of being radiopaque, not affected by blood offers two advantages, (i) faster setting time (12 minutes)
contamination, biocompatible and stimulates formation and (ii) better mechanical properties. Biodentine has
of cementoid tissue at the resected end. the potential of forming hydroxyapatite when in contact
with tissue fluids. Biodentine is biocompatible and
Disadvantages easily manipulated in the root-end cavities.
• Handling is difficult
• Toxic potential
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technical, biological and clinical testing. Endod. Topics: cones and Resilon. Aust. Endod. J.: 2007; 33:23–26.
2005; 12:25–38. 63. Tay FR, Pashley DH, Loushine RJ, Kuttler S, Garcia-Goday F,
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comparison of three different gutta-percha cones when
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55. Santos J, Tjaderhane L, Ferraz C, Zaia A, Alves M, De Goes 69. Von Fraunhofer JA, Kurtzman GM and Norby CE. Resin-based
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59. Shanahan DJ and Duncan HF. Root canal filling using Resilon: FR. A comparison of cohesive strength and stiffness of Resilon
a review. Br. Dent. J.: 2011; 211:81–88. and Gutta-percha. J. Endod.: 2006; 32:553–555.

20

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Chapter
21
Single-visit Endodontics

The endodontic therapy as a treatment modality to save iii. Is the failure/sequelae of treatment same with
teeth is gaining importance day-by-day. Over the years single visit endodontics?
the evolution in Ni-Ti instruments coupled with iv. Is the psychological acceptability same in single
improved techniques of root canal preparation and visit endodontics as for multiple visit endodontics?
precision obturation has helped the operator perform v. The commercial aspects should also be considered
endodontic procedures more effectively and efficiently. (can the operator charge same fee in single visit
The endodontic procedure is to be completed in how endodontics as in for multiple visits?)
many visits is not clearly documented. Even the Traditionally, the root canal treatment is performed
rationale of multiple visits is also not established. The in multiple visits, using intracanal medicaments along
long-term outcome is the standard by which treatment with irrigating solutions to eliminate microorganisms
methods are judged in medicine and dentistry. and toxins from the root canal system. The most
However, even long-term studies could not establish commonly used and widely accepted intracanal
the protocol of time/visits to be successful in endo- medicament is calcium hydroxide. It is hypothesized
dontic treatment. that the alkalinity (pH 11–12) of calcium hydroxide will
What do we achieve in endodontic treatment? kill the bacteria in the root canal and also dissolve the
Simply, it is the elimination of microorganisms and their endotoxins. However, calcium hydroxide is not capable
substrate from the pulp spaces, followed by three- of eliminating all bacteria; may help in bacterial
dimensional obturation so as to avoid subsequent reduction.
infections.
Similarly, use of various irrigants and intracanal
Can this goal be achieved in single visit? Or, the
medicaments could not fully eradicate the micro-
operator needs multiple visits to get rid of the micro-
organisms present in the root canal.
organisms along with substrate from the root canal. If
A plenty of surveys have been conducted to analyze
multiple visits are required to completely eliminate the
the reasons why not to complete root canal treatment
microorganisms and this is the only reason that vital
in one visit.
root canal treatment should always be carried out in
one visit. But, this is not true always. It seems there The possible reasons are:
might be other factors playing role in successful • The mechanical irritation of the instrumentation and
outcome of the endodontic treatment. extrusion of debris may cause postoperative pain and
The authors favoring single visit endodontics opine discomfort. However, with the advent of better
that the rationale for this treatment regime is less techniques and gadgets, coupled with experience of
stressful for the patients, well-accepted, time saving and the operator, this irritation and extrusion can be
reducing the risk of inter-appointment infections. Single minimized, subsequently, the postoperative pain.
visit endodontics is considered more productive and The fear of this pain warrants the operator to follow
less expensive. However, certain questions have been multiple-visit protocol.
raised regarding validity of single visit endodontics. • Most of the operators feel that chances of failure are
i. Is the same outcome achieved using single visit much more with single visit root canal treatment.
regime vis-à-vis multiple visit? However, it is not true. If the basic parameters are
ii. Is the postoperative healing same for single visit achieved in single visit without disturbing the
endodontics? surrounding periodontium, the success can be

366

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 Single-visit Endodontics 367

achieved. The simple parameter is whether the COMPARATIVE CLINICAL FEATURES

cleaning and shaping of the pulpal space can be The single visit and multiple visit endodontic proce-
achieved in one visit without disturbing the dures are compared clinically. The features considered
periodontium or the operator needs more time for important for the success of the treatment are:
the same. The chances of failure will be minimal if
the operator has the confidence of achieving the goal i. Endodontic flare-up and pain: The intraoperative
in one visit. flare-up and postoperative pain are correlated as
measure of success and failure with single visit root
• Many operators make excuse of lack of time in their
canal treatment. The mild pain during the treatment
clinical practice. Usually, the operator does ‘access
procedure, is however, considered normal and has
opening’ on day one, ‘cleaning and shaping’ on day
no effect on the final outcome of the treatment. Post-
two and ‘obturation’ in third visit. In between, if the
operative pain can be due to over instrumentation,
patient is not comfortable, ‘dressing’ can be repeated.
pushing of debris or irritating the periodontium by
The inter-appointment change of dressing only kills
any means. It is established that there is no
bacteria for the time being. It does not necessarily
significant difference in postoperative pain when
prepare the canal or in any form achieve the
single visit is compared with multiple visit root
objectives. In case the patient has sufficient time, the
canal treatment (Table 21.1).
root canal treatment objectives can be achieved in
single visit. Multiple visits might waste more time ii. Postoperative healing: The postoperative healing
in adjusting the patient on the chair, isolation, is considered as the main feature of success and
removal of existing temporary filling and irrigation, failure of endodontic treatment. The short- and long-
etc. Single visit treatment makes sense in busy term follow-up of the radiograph is the commonly
practice to save overall time. used technique to evaluate bony pattern/healing.
• Another important issue is economical viability. The Numerous studies have established and reported
commercial aspect of any treatment modality is as no significant difference in healing process between
good as any other factor for the success of the the single and multiple visit treatment protocol
treatment. A few operators believe that in case of (Table 21.1). A few authors opine that the clinical
single visit modalities, the charges cannot be the criteria for success should not be dependent only
same as for multiple visits. However, this notion is on pain and flare-ups. The clearly defined clinical
purely on assumptions. The charges can be fixed and criteria should be followed in studies comparing
vary according to the operator and the surroundings. single visit and multiple visit endodontic proce-
Secondly, one should not underestimate the patients. dures.
The patients are willing to pay more if it saves their iii. Elimination of bacteria and bacterial toxins: The
time. main objective of root canal treatment is to eradicate
The concept of single visit root canal treatment is bacteria and bacterial toxins, so as to provide
based on the theory of obscure or inhume; which bacteria free environments for healing. The lipo-
implies that majority of microorganisms are removed polysaccharide (LPS) is considered as the most
during preparing and irrigating the canals and the powerful endotoxin capable of having strong toxic
remaining bacteria get obscured or inhumed in the effect on periapical tissues. The accumulation of
dentinal tubules after the root canal obturation. Such bacterial components in any area along with endo-
bacteria do not survive long because of lack of nutrition toxins can stimulate the release of pro-inflammatory
and spacing. The antimicrobial activities of sealers cytotoxins.
during obturation and also the zinc of gutta-percha may The irrigating solutions have been found to be
kill the residual bacteria. ineffective against most of the endotoxins; whereas,
The persistence and reinfection in the root canal can intracanal medication with calcium hydroxide
be minimized by either dressing the canal with inactivates the cytotoxic effects of endotoxins. It is
antimicrobial agents in multiple visits or immediately established, however, that root canal preparation
obturate the canal to reduce the space for bacterial followed by sodium hypochlorite irrigation render 33%
colonization in a single visit protocol. The success of of the root canal bacteria-free in first appointment. An
root canal treatment is based on careful case selection. irrigant could attain complete eradication of bacteria;
There should be no compromise with the judicious
preparation of root canal without injuring the perio-
dontium.
even calcium hydroxide and other intercanal
medicaments fail to obtain the total elimination of
bacterial organisms.
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Table 21.1 Studies on postoperative complications with single-visit endodontic treatment

Authors (year) Method (samples) Clinical complications Success rate (healing)
Rudner and Oliet (1981) 283 cases No significant difference in No significant difference
Single visit: 98 teeth the incidence and severity of
Multiple visits: 185 teeth postoperative pain between
the two groups
Mulhern et al (1982) 60 teeth treated by 2 operators No significant difference in the No significant difference
Single visit: 30 single-root teeth incidence of pain existed
Multiple visits: 30 single-root between the single and
teeth multiple-visit groups
Evaluation period: 2 days
Roane et al (1983) 359 patients Multiple-visit treatment had a —
Single visit: 250 teeth greater incidence of post-
Multiple visits: 109 teeth operative pain
Pekruhn et al (1986) 925 teeth treated by one operator No clinical difference The overall success rate
for single-visit treatment was 95%
Evaluation period: 1 year (the incidence of failure
was higher with retreatment
and presence of apical
periodontitis)
Trope (1991) 226 teeth for single-visit treatment No flare-up in cases without pre- —
(treated by one operator) existing symptoms
Higher flare-up rate in retreatment
cases with pre-existing symptoms
Trope et al (1999) 102 teeth with apical periodontitis — Both groups had a similar
Single visit: 45 teeth success rate
Multiple visits: 57 teeth
Evaluation period: 1 year
Peters and Wesselink (2002) 39 patients treated by one operator No significant difference No significant difference in
Single visit: 21 teeth success rate between the
Multiple visits: 18 teeth two groups
Evaluation period: 4.5 years
DiRenzo et al (2002) 72 molars treated by two operators No difference in postoperative No significant difference
Single visit: 39 teeth pain between the two groups
Multiple visits: 33 teeth One patient (1.3%) in the multiple-
Evaluation period: 2 days visit group with pre-existing apical
periodontitis experienced flare-up
Field et al (2004) 223 teeth single visit (both No clinical complication The overall success rate
anterior and posterior) was 89.2%.
No significant difference
based on sex and age
Anterior teeth were more
successful than posterior
teeth
Kvist et al (2004) 96 teeth with apical periodontitis — No significant difference
Single visit: 48 teeth between the two groups
Multiple visits: 48 teeth
Yoldas et al (2004) 218 retreatment cases Multiple-visit root canal treatment —
Single visit: 106 teeth was more effective in completely
Multiple visits: 112 teeth eliminating pain that was due to
Evaluation period: 1 week single-visit treatment of previously

21 symptomatic teeth
(Contd…)

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 Single-visit Endodontics 369

Table 21.1 Studies on postoperative complications with single-visit endodontic treatment (Contd…)
Authors (year) Method (samples) Clinical complications Success rate (healing)

Waltimo et al (2005) 50 teeth with apical periodontitis No clinical complication No significant difference in
Single visit: 48 teeth healing between the two
Multiple visits: 30 teeth groups
Evaluation period: 52 weeks
Molander et al (2007) 101 teeth No clinical complication No significant difference
Single visit: 53 teeth in healing between the
Multiple visits: 48 teeth two groups
Evaluation period: 24 months
Penesis et al (2008) 63 patients No clinical complication No significant difference in
Single visit: 33 healing between the two
Multiple visits: 30 groups
Evaluation period: 12 months
Risso et al (2008) 118 molars with necrotic pulp The frequencies of postoperative —
Single visit: 57 teeth pain were 10.5% and 23% for the
Multiple visits: 61 teeth single-visit and multiple-visit group,
Evaluation period: 10 days respectively
Kalhoro and Mirza (2009) 100 patients for single-visit No flare-ups in 1 month (safe in No significant difference
treatment both vital and nonvital teeth,
Evaluation period: 1 month and even in teeth with periapical
pathosis)
Ince et al (2009) 306 patients treated by two No significant difference between No significant difference
clinicians vital and nonvital teeth between the two groups
Single visit: 153 teeth
Multiple visits: 153 teeth
Evaluation period: 3 days
Wang et al (2010) 89 treated incisors by two No significant difference on No significant difference
endodontists the incidence and severity of
Single visit: 43 teeth postoperative pain between
Multiple visits: 46 teeth the two groups
Evaluation period: 7 days
El Mubarak et al (2010) 234 teeth Overall incidence of postoperative No significant difference
Single visit: 32 teeth pain was 9% after 1 day between the two groups
Multiple visits: 202 teeth
Evaluation period: 1 day
Prashanth et al (2011) 32 cases No significant difference in post- No significant difference
Single visit: 16 teeth operative pain, or tenderness with in success between the
Multiple visits: 16 teeth either single-visit or multiple- two groups
Evaluation period: 6 weeks visit therapy
Paredes-Vieyra and 282 teeth with apical periodontitis No clinical difference No significant difference in
Enriquez (2012) Single visit: 146 teeth healing between the two
Multiple visit: 136 teeth groups
Evaluation period: 2 years
Dorasani et al (2013) 64 single root teeth No clinical difference No significant differences
Single visit: 34 teeth in healing between the
Multiple visits: 30 teeth two groups
Akbar et al (2013) 100 molars No clinical difference No significant difference in
Single visit: 50 teeth the flare-up rate between
Multiple visit: 50 teeth two groups

(Contd…)
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 370 Essentials of Endodontics

Table 21.1 Studies on postoperative complications with single-visit endodontic treatment (Contd…)
Authors (year) Method (samples) Clinical complications Success rate (healing)

Xavier et al (2013) 48 nonvital teeth Two visits were more effective No difference in
Single visit: 24 teeth than one visit in reducing eradicating micro-
Multiple visits: 24 teeth endotoxins organisms
Evaluation period: 2 weeks
Bhagwat and Mehta (2013) 60 patients in single-visit No difference of pain in vital No significant difference
treatments and nonvital teeth without apical
Evaluation period: 2 weeks radiolucency. (Teeth with periapical
radiolucency exhibited less pain
than teeth without periapical
radiolucency)
Rao et al (2014) 140 patients in single visit and No difference of postoperative No significant difference
multiple visit pain

It is argued that single visit root canal treatment is Single visit treatment should be avoided in vital teeth (collagen
more effective in entombing the bacteria in dentinal pulp tissue at the apical constriction area may create
tubules, which later die because of lack of nutrition and problem in later stages).
the overall healing is effected by the immune mecha-
nisms of the individual. A few authors opine, depending Indications
upon their studies, that the obturation should be carried • Fractured teeth, especially anteriors, which need
out after completely eradicating the bacteria. This immediate restorations
feature could not be achieved in one visit treatment • Apprehensive but cooperative patient
because it is not possible to eradicate all infections from • Physically compromised patients who cannot visit
root canal without the support of inter-appointment dental office too often
dressing using various medicaments (Fig. 21.1a and b). • Uncomplicated nonvital teeth
• Teeth having sinus tract.

Contraindications
• Patients having acute periodontium with severe pain
• Teeth with limited access
• Patients with temporomandibular joint disorders
(cannot open the mouth for long)
• Chronic periapical lesions of long-duration
• Teeth with aberrant canal anatomy.

Advantages
a
• The operator is aware of the intricacies of canal
anatomy immediately following preparation. No risk
of losing important landmark.
• The canal is always cleaner immediately after
preparation. Root canal dressings and medicaments
may hamper with the cleanliness.
• The risk of flare-up induced by temporary fillings
and inter-appointment period is minimal.
• The risk of fracture of endodontically treated teeth
is reduced, since, the final restoration can be placed
immediately (most of such teeth fracture during

21 endodontic treatment).
b
Fig. 21.1 Single visit root canal treatment (mandibular first • Patient’s preappointment anxiety and post-operative
molar): (a) Preoperative; (b) Postoperative discomfort are limited to one day only.

t.me/Dr_Mouayyad_AlbtousH
 Single-visit Endodontics 371

• Time is saved; both for the patient and the operator. multiple visits. Patients with alveolar abscess/
• The working length remains constant, which might swelling should also be treated in multiple visits.
deviate during multiple visits because of change of e. Vitality of teeth: Whether vital teeth should be root
reference point. canal treated in a single visit remained controversial.
• Minimizes incomplete treatment. Many patients do Majority of authors believe that vital teeth are easy
not turn for final restoration if the pain has subsided to be treated in single visit; however, a couple of
and the tooth is functioning reasonably well. authors claim that the complete pulp extirpation is
• Esthetically acceptable since, the tooth is restored in difficult in apical area, which can later cause
the same appointment (especially anterior teeth). problems. Any pulp remnant left at the apical
constriction area, which can happen generally in
Disadvantages posterior teeth will harbor microorganisms in few
weeks leading to failure of root canal treatment.
• Longer working time might be tiring for the patient,
Multiple visits will be preferred so as to completely
especially the older adults and the patients suffering
clean the area of any pulp tissue.
from heart diseases. The longer time may affect
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15. Kenrick S. Endodontics: a multiple-visit or single-visit periodontitis: a systematic review and meta-analysis. Int.
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16. Kvist T, Molander A, Dahlen G and Reit C. Microbiological 29. Siqueira JF and Rocas IN. Optimising single-visit disinfection
evaluation of one- and two-visit endodotic treatment of teeth with supplementary approaches: a quest for predictability.
with apical periodontitis: a randomized, clinical trial. J. Aust. Endod. J.: 2011; 37:92–98.
Endod.: 2004; 30:572–576.
30. Spangberg L. Evidence-based endodontics: The one-visit
17. Mohammadi Z, Farhad A and Tabrizizadeh M. One-visit treatment idea. Oral Surg., Oral Med., Oral Path., Oral Radiol.
versus multiple-visit endodontic therapy—a review. Int. Dent. Endod.: 2001; 91:617–618.
J.: 2006; 56:289–293.
31. Trope M and Bergenholtz G. Microbiological basis for
18. Molander A, Warfvinge J, Reit C and Kvist T. Clinical and endodontic treatment : can a maximal outcome be achieved
radiographic evaluation of one- and two-visit endodontic in one visit? Endod. Topics: 2002; 1:40–60.
treatment of asymptomatic necrotic teeth with apical
periodontitis: a randomized clinical trial. J. Endod.: 2007; 32. Trope M, Delano EO and Orstavik D. Endodontic treatment
33:1145–1148. of teeth with apical periodontitis: single vs multivisit
treatment. J. Endod.: 1999; 25:345–350.
19. Mulhern JM, Patterson SS, Newton CW and Ringel AM.
Incidence of postoperative pain after one-appointment 33. Trope M. Flare-up rate of single-visit endodontics. Int. Endod.
endodontic treatment of asymptomatic pulpal necross in J.: 1991; 24:24–26.
single-rooted teeth. J. Endod.: 1982; 8:370–375. 34. Vera J, Siqueira J, Ricucci D, Loghin S, Fernandez N, Flores
20. Paredes-Vieyra J and Enriquez FJ. Success rate of single-versus B and Cruz AG. One-versus two-visit endodontic treatment
two-visit root canal treatment of teeth with apical peridontitis: of teeth with apical periodontitis: a histobacteriologic study.
a randomized controlled trial. J. Endod.: 2012; 38:1164–1169. J. Endod.: 2012; 1–13.
21. Pekruhn RB. Single-visit therapy: a preliminary clinical study. 35. Waltimo T, Trope M, Haapasalo M and Orstavik D. Clinical
J. Am. Dent. Assoc.: 1981; 103:875–877. efficacy of treatment procedures in endodontic infection
control and one year follow-up of periapical healing. J.
22. Pekruhn RB. The incidence of failure following single-visit
Endod.: 2005; 31:863–866.
endodontic therapy. J. Endod.: 1986; 12:68–72.
23. Penesis VA, Fitzgerald PI, Fayad MI, Wenckus CS, BeGole 36. Wang C, Xu P, Ren L, Dong G and Ye. Comparison of post-
EA and Johnson BR. Outcome of one-visit and two-visit obturation pain experience following one-visit and two-visit
endodontic treatment of necrotic teeth with apical root canal treatment on teeth with vital pulps: a randomized
periodontitis: a randomized controlled trial with one-year controlled trial. Int. Endod. J.: 2010; 43:692–697.
evaluation. J. Endod.: 2008; 34:251–257. 37. Xavier AC, Martinho FC and Chung A. One-visit versus two-
24. Peters LB and Wesselink PR. Periapical healing of visit root canal treatement: effectiveness in the removal of
endodontically treated teeth in one and two visits obturated endotoxins and cultivable bacteria. J. Endod.: 2013; 39:
in the presence or absence of detectable microorganisms. 959–964.
Int. Endod. J.: 2002; 35:660–667. 38. Yilmaz Z, Ozdemir HO and Gorduysus O. Evaluation of
25. Prashanth MB, Tavane PN, Abraham S and Chacko L. single and multiple visit root canal therapy: a randomized
Comparative evaluation of pain, tenderness and swelling clinical cases. Clin. Dent. Res.: 2012; 36:59–63.
followed by radiographic evaluation of periapical changes 39. Yoldas O, Topuz A, Isci AS and Oztune, H. Postoperative
at various intervals of time following single and multiple visit pain after endodontic retreatment: single-versus two-visit
endodontic therapy: as in vivo study. J. Contemp. Dent. Pract.: retreatment. Oral Surg., Oral Med., Oral Path., Oral Radiol.
2011; 12:187–191. Endod.: 2004; 98:483–487.

21

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 Chapter
22
Postendodontic
Restorations

The endodontically treated teeth usually undergo a and in mesio-occluso-distal preparation, the loss of
considerable loss of tooth structure because of caries, stiffness is 60%.
iatrogenic loss and also the access cavity preparation. ii. Physical changes: It is believed that root canal
The fracture resistance of these teeth is also affected by treatment leads to dehydration, consequently
the amount of substance loss. weakening the tooth. A few authors, however, do
The restoration of endodontically treated tooth not favour this notion, claiming that dentin
involves replacement of missing tooth structure along hardness is not altered after endodontic treatment.
with protection of the remaining tooth. The remaining The loss of moisture content from the dentin may
tooth structure is important in planning and executing lead to loss of translucency of the tooth.
the restoration of endodontically treated teeth. The iii. Altered appearance: The root canal treated tooth may
factors, which should be considered by the operator show altered appearance because of presence of
are; the strategic position of the tooth in the arch, the residual pulp remnants and even medicaments. The
occlusal load, which the tooth will be bearing, overall chemically altered dentin reflects light differently,
occlusal pattern and also the oral hygiene of the patient. which modifies the overall appearance of tooth.
To replace the missing tooth structure, the operator iv. Proprioception: Sense of proprioception is lost in root
should decide whether the retention is to be achieved canal treated teeth. Neurosensory feedback
through root canals or the remaining tooth structure. mechanism is impaired because of loss of pulpal
Achieving adequate retention and resistance features tissues. Decrease in mechanoreceptive feature may
for final restoration is always challenging. Over the lead to inadvertent biting on nonvital teeth,
years, various materials and techniques have been subsequently fracture of the tooth.
developed to ensure retention, resistance and esthetics
of postendodontic restorations. Postendodontic changes
Effect of root canal treatment on the tooth • 10% reduction of collagen bonded water
After the root canal treatment, the tooth exhibits certain • Aging of collagen (changes in cross-linking)
morphological and physical changes, such as: Not much change in
• Modulus of elasticity (young modulus)
i. Loss of tooth structure: The tooth structure might
• Dentin hardness
have been lost prior to the treatment because of
• Fracture resistance
caries and fracture, etc. The endodontic procedures,
such as access cavity preparation or involuntary
cutting during negotiating root canals also lead to PLANNING POSTENDODONTIC RESTORATIONS
loss of tooth structure. The bulk of remaining dentin The restoration of endodontically treated teeth is
is important since, the strength of tooth is propor- planned following the guidelines as:
tional to it. As the bulk of dentin is decreased, the • The root canal treatment should be of good quality.
stiffness of the tooth is decreased. It is established Only clinical asymptomatic feature will not be
that even the conservative access cavity preparation sufficient. Radiological assessment is mandatory;
decreases the stiffness of the tooth by 5%; whereas, however, computer aided radiography is preferred
in class II preparation there is 40% loss of stiffness in evaluating the quality of obturation.

373

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 374 Essentials of Endodontics

• The common notion that endodontically treated teeth The salient features of this record are:
fracture easily because of increased brittleness may i. The remaining dentin volume is calculated either
not be correct; the amount of remaining tooth by scanning the cast using a laser profilometer or
structure controls the fracture resistance of the tooth. weighing the remaining die stone and calculating
The operator should take extra care so that the loss the equivalent dentin volume.
of tooth structure during root canal preparation and ii. Since, the volume of remaining dentin may not
tooth preparation, be minimized. The root canal reflect the strategic contribution of dentin, it became
treated tooth with sufficient amount of dentin can apparent that an index assessing the remaining
be restored without the need of extra retentive dentin would be useful.
devices.
• The reinforcement of remaining tooth structure with Tooth Restorability Index (TRI)
bonded materials can also be planned. The long-term Tooth Restorability Index (TRI) was developed to
validity of this reinforcement with time is question- provide a structured assessment using defined para-
able; however, the treatment is effective in teeth with meters to evaluate remaining coronal tissue (Fig. 22.1).
less surface area remaining (e.g. premolars). • The tooth is divided into six equal sextants: 2
• The operator should analyze all factors before proximal, 2 buccal and 2 lingual areas.
placing post, especially in the posterior teeth. The • TRI allowed scores of 0–3 in each tooth sextant with
post in posterior teeth is avoided as far as possible. a maximum score of 18 per tooth.
The post is placed only to retain core. A few authors • The contribution of each tooth sextant (remaining
are of the view that the post and core should be of dentin) to retention and resistance form can be
the same material. It minimizes the vertical stresses recorded following the score.
and is also time saving. • Experienced clinicians (three or more) can evaluate
• Length of the postdepends on the configuration of the casts regarding the remaining dentin.
the core required and the length of the root. The
A scoring system of 0–3 was allocated to each section.
amount of stresses, which destabilize the restora-
‘0’—None: Throughout two-thirds or more of the tooth
tions, should also be considered.
sextant under consideration; there is no axial wall of
• The removal of gutta-percha always disturbs the
dentin (i.e. a box or missing cusp) or any dentin present
apical seal. Early or delayed removal of gutta-percha
above the finishing line is so lacking in height that may
might not be significant in disturbing the apical
not be able to contribute to retention and resistance
seal; however, early removal is preferred. Quick
form. The score is appropriate where a margin is visible
removal of gutta-percha at the predetermined length
just apical to the limit of a missing wall, but there is
with heated instruments is considered a better
only a small bevel or chamfer comprising the preparation
method.
dentin.
SELECTION OF RESTORATION FOR ‘1’—Inadequate: Coronal dentin is present in the tooth
ENDODONTICALLY TREATED TEETH sextant but in terms of thickness, height or configuration
The primary aim of postendodontic restoration is to
protect the remaining tooth tissue, maintaining the
occlusal function and esthetics of the replaced tooth
tissue. The amount of remaining tooth structure before
and after tooth preparation is important for the long-
term success/failure of the restoration. The remaining
coronal tooth structure after tooth preparation must be
analyzed thoroughly and recorded. Prior to restoration
of these teeth, a decision is to be taken whether the
support from root is required or not.

Aims of postendodontic restorations

• Replacement of missing tooth structure

22
• Protection of remaining tooth structure
• Maintenance of occlusal functions
Fig. 22.1 Tooth restorability index (TRI): Scoring sextants
• Esthetics (diagrammatic)

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 Postendodontic Restorations 375

(e.g. an undercut) that is insufficient to make any

predictable contribution to retention and resistance
form as opined by the operator. Dentin walls less than
1.5 mm thick or more than twice as high as their thinnest
part would be included in this category.
‘2’—Questionable: More dentin is present than in ‘1’,
but clinically, it will not make predictable contribution
to retention and resistance. This score should only be
assigned where the operator finds it difficult to deter-
mine whether a score of ‘1’ or ‘3’ is more appropriate.
‘3’—Adequate: There is sufficient coronal dentin in terms
of height, thickness and the operator is confident that
the distribution of forces would provide the requisite
resistance and retention form to the final restoration.
a
Although tooth restorability index helps deciding the
type of restoration for endodontically treated teeth,
there is no definite consensus regarding the choice of
the final restoration. The brittle nature of endodonti-
cally treated teeth and also the lack of moisture in these
teeth have been disproved. It is established that the
thickness of the residual dentinal walls and cusps
are the key factors. As cavity size increases and the
marginal ridges are lost, the structure durability
decreases. For this reason only the full coverage crowns
are preferred in such teeth (Fig. 22.2a and b); otherwise,
if the structural durability is sufficient, alternatives such
as covering functional cusps (Fig. 22.3), bonded
restorations (Fig. 22.4) and pinlays can be planned.
Composite crowns, which need less tooth reduction, b
are also used these days. Cusp covering with indirect Fig. 22.2 Full veneer crown
composite restorations is also effective.

Key features in decision-making

• Consider structural durability and esthetics
• Amount of available dentin thickness after removing caries,
restorative materials, etc.
• The remaining tooth structure’s ability to retain the core
• For full coverage crowns, make balance between esthetics
and occlusal load
• Patient’s consent before finalizing the restoration

A classification is proposed, which guides the

choice of restoration in endodontically treated teeth
(Flowchart 22.1)
Type I: More than half the tooth structure is present
(Fig. 22.5a)
Type II: Less than half the tooth structure present
(Fig. 22.5b)
Type III: Coronal tooth structure absent or minimum
(Fig. 22.5c)
Type IV: Root embedded (Fig. 22.5d) Fig. 22.3 Covering functional cusps with cast metal
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 376 Essentials of Endodontics

Fig. 22.5c Coronal tooth structure absent or minimum

Fig. 22.4 Bonded restoration

Fig. 22.5d Root embedded

Flowchart 22.2 depicts protocol of selecting

restoration for endodontically treated teeth.
The selection of post-core restoration or only coronal
filling depends upon the remaining walls (tooth is
considered to have five walls; buccal, lingual, mesial,
distal and occlusal).
The tooth to receive restoration should be evaluated
thoroughly before initiating restorative procedures. The
features evaluated are:
Fig. 22.5a More than half the tooth structure present
a. Endodontic: The tooth should be asymptomatic;
properly root canal treated and filled with
appropriate coronal restorative material. Partially
filled root canals, may and may not be symptom-
free, should not be restored with permanent
restorations (Fig. 22.6a and b).
b. Periodontal: The tooth should be stable in the arch
and also able to withstand masticatory/functional
forces. The crown-root ratio should be favorable
(Fig. 22.7a and b).
c. Restorative: The position of the tooth in the arch
and also the strategic value should be evaluated
22 Fig. 22.5b Less than half the tooth structure present
before initiating definitive restoration (Fig. 22.8a
and b).

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 Postendodontic Restorations 377

Flowchart 22.1: Classification guiding the choice of restoration

Flowchart 22.2: Protocol of selecting restoration for endodontically treated teeth

Condition of remaining walls Photo representation Treatment option

One wall missing (only access cavity) • Fill access cavity/missing wall
• No need of post

Two walls missing • Fill the coronal cavity/core preparation

• Full crown coverage

Three walls missing • Need of post

• Select post followed by coronal
coverage

Four walls missing • Need of post

• Crown lengthening/orthodontic extrusion
may require
• Final coronal coverage

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 378 Essentials of Endodontics

a b
Fig. 22.6 Endodontic evaluation: (a) Faulty obturation; (b) Incomplete obturation

a b
Fig. 22.7 Periodontal evaluation: (a) Insufficient bone support; (b) Insufficient crown-root ratio

a b
Fig. 22.8 Restorative evaluation: (a) Poor coronal restoration; (b) Position of tooth in the arch

POSTCORE RESTORATIONS root(s) should be thoroughly assessed before initiating

The substitution of the crown portion, with or without the postpreparation.
The root/root canal should be assessed for following
the help of pins, is referred to as ‘core’. The root canal
features:
support of the core, may be metallic or of any other
• Remaining coronal/incisal tooth structure present
material, is referred to as ‘post’ or ‘dowel’. Collectively along the root
the system is known as ‘post and core’ or ‘postcore’ • Quantum of occlusal load, which the restored tooth
system. The resistance and retention form is preferably
22 achieved from the core only, without the root canal
support. In case the post/dowel is mandatory, the
will be bearing
• Configuration of the root canal
• Thickness of dentin around the root canal

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 Postendodontic Restorations 379

• Amount of dentin, which can be utilized in prepara- 3. Generation III (Esthetics and radiopaque)
tion of post (2001 onwards)
• Number of root canal(s) required for postplacement • DT light post
• Caries/resorption inside the root, if any • DT light postillusion
• Periodontal (bony) support of the root • Snow light (snow post)
• Possibility of extra retentive devices, if any • Rely-X post
• Sufficient length of the post, which can be achieved • FRC postec plus.
from the root canal.
Types of Posts
Functions of Post
I. Metal posts
The post serves the following functions:
A. Custom cast metal posts
• It retains core, which helps in reinforcement of the
lost tooth structure. B. Prefabricated metal posts
• It resists the tensile forces, which tend to pull the a. Passive posts
restoration away from the tooth. i. Tapered
• It distributes occlusal forces along the length of the • Smooth
roots to the periodontium (crowns of endodontically • Serrated
treated teeth are usually damaged to an extent that ii. Parallel
the remaining tooth structure cannot distribute the • Smooth
forces along the natural ways). • Serrated
• It maintains the marginal integrity of the final b. Active posts
restoration by providing sufficient rigidity at the i. Tapered
margins; prevents breakdown of cement medium at • Self-threaded
the tooth-restoration interface.
ii. Parallel
Classification of Posts • Self-threaded
The posts are classified as: II. Fiber posts
A. Custom fiber post
Class I: Self-retentive metal posts (post with self-cutting B. Prefabricated fiber posts
threads or different types of screws) a. Carbon fibers
Class II: Metal posts with passive retention (no direct i. Mirafit carbon
contact between the post and the root canal wall. The ii. Endopost
post needs luting cement for the space present between iii. Carbonite system
post and the root canal wall). iv. CF-post
Class III: Non-metal posts with passive retention (fiber b. Silica fibers
reinforced posts and ceramic posts along with adhesive i. Quartz fibers
cement). • Aesthetic-post
Class IV: Biological posts (dentin posts along with • Aesthetic-plus
adhesive cement). • Style-post
The fiber posts have also been categorized as • Light/light DT post
‘generation’, based on radiopacity and their esthetic ii. Glass fibers
appearance. The categorized generations are:
• Snow post
1. Generation I (neither radiopaque nor esthetic)
• Mirafit white
(Mid 1980s)
• Lucent anchor
• Composipost
• C-post • FiberKor post
2. Generation II (esthetic but not radiopaque) • Fiber white parapost
(Mid 1990s) c. Polyethylene fibers
• Esthetic-plus • Ribbond/Ribbond THM
• Light-post • Construct
d. Fiber post with gutta-percha
• Fiber white
• FiberKor
• Lucent anchor
• Fiberfill post system
III. All-ceramic posts
22

t.me/Dr_Mouayyad_AlbtousH
 380 Essentials of Endodontics

IV. Dentin posts (biological post) B. Prefabricated Metal Posts

V. Miscellaneous post systems The different shapes and sizes of the post is pre-
a. Two piece custom post (split cast metal post and fabricated and designed to fit in a prepared canal space.
core) This differs from the custom cast post; the canal is
b. Post-inlay system prepared according to the prefabricated post. The
VI. Intraradicular rehabilitation with light transmitting resulting fit may or may not be exact; however,
plastic posts. clinically acceptable post can be selected.
The prefabricated posts are made of metal (usually
steel and titanium) or plastic (plastic prefabricated posts
I. METAL POSTS
are described in subsequent pages). The posts are
Metal posts can be custom cast and are also available available in tapered and parallel configuration. Further,
as prefabricated metal posts. the shapes can be smooth or serrated; the serrated ones
offer better retention.
A. Custom Cast Metal Posts
Advantages
Custom cast metal posts are fabricated from a negative
reproduction of the prepared root canal. The impression • Easy manipulation
is made of the prepared postspace, using wax or cold • Less time consuming
cure resins; referred to as ‘pattern’. The pattern is • Easy retrieval (passive post) as compared to custom
invested and the cast is prepared using an appropriate metal posts
alloy. Type III and Type IV gold alloys are preferred • Better retention; especially serrated, parallel posts
alloys; however, the base metals and titanium alloys • Cost-effective.
are also being used. The custom cast posts conform to
the configuration of the prepared canal. The custom Disadvantages
cast metal posts are preferred in single rooted teeth. • Rigidity may lead to root fracture
• Active posts are difficult to remove
Indications
• Alloy may corrode (long-term failure)
• Teeth with elliptical/flared canals
• Not feasible in tortuous canals
• Teeth where alignment of the proposed crown is
significantly different from the inclination of the • Extra removal of dentin may be required to adjust
canal (mostly in anterior teeth) the size of post in the canal.
• Availability of adequate space for bulk of the build- Prefabricated posts are mainly of two types:
up material around the post
• When multiple teeth require posts, it is advisable to a. Passive Posts
make an impression and fabricate the post in labora- The passive posts drive retention from their close
tory rather to build in clinic. proximity to the dentin walls; mostly by adherence of
Advantages the cementing medium. The types of passive posts are:
• Conform to the root canal configuration (usually i. Tapered posts
tapering) The taper designs usually simulate the root canal
• Strong configuration, thereby lessening the chance of a lateral
• Core is an inherent part of post (provide stability) perforation. Tapered posts exhibit least stresses during
• Core can be fabricated at different angle, if need be cementation; however, they may create a wedging effect
• More effective in single rooted teeth inside the root.
• Do not induce any stress during installation. The currently available tapered posts exhibit taper
ranging from 1.1 to 6.2°. The tapered posts are selected
Disadvantages according to the size of the reamer or file last used for
• May act as wedge during load transfer the preparation of the canal.
• Venting is required during cementation The size at the apex is usually 1.0, 1.2, 1.3 and
• Taper posts are less retentive than parallel posts 1.6 mm and correspondingly the diameter is increased
• Difficulty in retrieval during retreatment
22 • Rigidity may lead to fracture of root
• Certain metals may corrode (long-term failure).
coronally. Two diameters (numbers) are indicated in
one size; the diameters at the tip and second 10.0 mm
from the tip.

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 Postendodontic Restorations 381

The different tapers and sizes are available, suitable • Whaledent parapost system: This post system provides
for different root canal configurations. The commonly the most equitable distribution of masticatory forces.
available tapered passive (smooth sided) posts are Kerr It has three designs; viz. parapost, parapost plus and
endopost and Mooser post. These are the least retentive unity post system. All are passive, parallel and
of all post designs. vented (Fig. 22.9a to d).
These are made of either stainless steel or titanium.
ii. Parallel posts
The vertical channels on the parapost, spiral flutes
The posts may have a serrated or smooth surface.
and/or grooves on parapost plus and a raised
Smaller diameter of such posts are also used as
diamond pattern on unity posts provide extra
accessory retentive devices (as accessory pin into
retention when used with luting cements.
coronal dentin of root trunk). It is also necessary to
• Boston post system: The Boston post resembles a
evaluate the dentin available for placing the pin, if
parapost without the vertical venting channel. It is
required. If there is insufficient available dentin, key-
made of titanium with horizontal non-engaging
ways can be prepared around the post. The parapost
serrations. These are also available with deeper
(serrated parallel post) is manufactured with a groove
grooves and rough surfaces.
running its entire length, which acts as a cement vent.
• Parkell parallel post system: This is a passive, vented,
The post should be large enough to accommodate
serrated post with an antirotational lock that fits into
as far the coronal portion of the canal as possible, but
the prepared root canal space.
must leave an adequate thickness of dentin at the apical
end. • Parallel post with tapered apical ends: These posts were
designed to provide better retention achieved by
The parallel posts provide greater retention and
parallel posts (coronal half) along with tapered post
create less stress than tapered posts, e.g. Whaledent
conforming to the tapered apical half of the canal. It
parapost, the Boston post and the Parkell parallel post.
is of two types:
A modified design of parallel-sided post with tapered
apical end is also available (Schanker’s design). – Degussa: The straight and tapered portions are
generally of equal lengths and are smooth.
Parallel post Tapered post – Unitek BCH system: Fine serrations are provided
• More retentive • Less retentive along parallel sides of the post and a smooth apical
• Create less stresses • Creates more stresses taper of 2.0 mm.
• No wedging effect • Creates wedging effect • Integra-post system: The integra-post system is made
• Need of extraremoval of • No need of extraremoval of the titanium alloy. It is biocompatible, corrosion
dentin of dentin resistant and stiff as well. The parallel passive design
• Chances of perforation of • Wedging may lead to root conserves tooth structure and minimizes stress. The
dentinal apical end fracture; no chance of mid-flange design of the post-effectively control
dentin perforation
stresses in the canal.

a b c d
Fig. 22.9 (a) Parapost (outer); (b) Parapost (inner); (c) Parapost XH (outer); (d) Parapost XH (inner)
22

t.me/Dr_Mouayyad_AlbtousH
 382 Essentials of Endodontics

b. Active Posts full length. V-lock posts are supplied with precise
The active posts depend primarily on engaging the drills that prepare a parallel walled canal just slightly
dentin directly. The threads on the post either screw larger than the shaft. The post is inserted along with
into the dentin, or fit into threaded channels (prepared luting cement. V-lock posts are less retentive,
in the dentin) and ‘tapped’ like a bolt. These are more comparable to passive paraposts.
retentive than passive cemented posts. The self- • Radix-anchor system: It differs from V-lock posts by
threading posts produce the greatest stresses when the quality of threads (sharp threads extend only
installed in the root dentin. These posts act as a wedge partly down the shaft). It is vertically vented and
and may induce fracture lines into the dentin. The types fits along the root surface. Luting cements are utilized
of active posts are: for the placement of post.
• Post with pretapped channels: These posts employ
i. Tapered self-threaded threads on their sides for retention and are inserted
The tapered self-threaded posts are available in into the canal whose walls are prethreaded with a
different sizes, diameter and lengths. The overall taper specially designed instrument. The luting cement is
varies from 3.0 to 30° (taper for the tip is 1.0 to 3.0°). It utilized for placement of posts in the root. These are
is frequently used on teeth having minimum of coronal two to three times more retentive than parallel-
tooth structure and multiple divergent canals (e.g. serrated posts. These posts are parallel in design with
Dentatus screw posts) (Fig. 22.10). no vertical vent. They have rounded, high frequency
The threads cut into dentin by 0.1–0.2 mm. The threads that fit into counter threads ‘tapped’ into
channel to receive the post is prepared by a drill sized the dentin with a manual thread cutter. The dis-
0.1 mm larger than the diameter of the shaft of the post. advantage with this type of system is that there is a
The blades (threads) extend beyond the shaft by 0.2 mm potential for root fracture because of inherent
and engage into dentin. The retention is reinforced by stresses.
cementing the post using any dual-cure resin cement.
ii. Parallel self-threaded Factors affecting Selection of Posts
The parallel self-threaded posts are more retentive than The factors guiding selection of posts are:
tapered posts (offer maximum retention). a. Root canal configuration: Wider root canals are best
These posts produce stresses in the root, both at the suited for postpreparation, e.g. distal root canals of
apical end and coronal half of the root. It is mandibular molars and palatal root canals of
recommended to ‘back off’ or reverse the post by half maxillary molars. However, additional retention
turn to minimize the stresses when slight resistance to (reinforcing post) can be achieved from adjacent
threading is felt. smaller canals.
These posts are of three types. The first two have b. Root canal morphology: The shape of the prepared root
sharp threads and are vented to reduce hydraulic stress canal affect post selection. The narrow root canals,
during cementation. They differ only in their length of especially in the apical third (mandibular incisors)
threads along the shaft. The types are: are not indicative of parallel posts. The requisite
• V-lock posts: These posts have ‘microthreads’, dentin around the post may not be available with
extending 0.5 mm from the shaft and continue to the these root canals. A tapered post should be preferred.
When the outline of the canal is oval, it is difficult to
prepare a circular post channel to receive a parallel
post. In such cases, a metal custom post is fabricated
according to the shape of the canal.
c. Remaining coronal tooth structure: The ‘thumb rule’
says, when more than half the crown structure is lost,
post and core should be considered. The use of a post
should be considered for anterior teeth when one or
both proximal walls are missing and for posterior
teeth when two adjacent proximal walls are missing.
d. Occlusal forces: The occlusal forces on individual tooth

22 Fig. 22.10 Active screw post

are influenced by various factors, viz. tooth type,
presence or absence of adjacent teeth, function of
tooth in the arch and oral habits of the patient.

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 Postendodontic Restorations 383

Factors affecting Post Retention 2. Post Taper

The factors affecting retention of post are: The parallel posts are approximately twice more
retentive than tapered posts (Fig. 22.12). The tapered
1. Post Length posts tend to produce greater stress in the shoulder area
The accepted principle regarding the post length is of the restoration, while the parallel post causes more
‘more the length, more the retention’. It is established that stress in the apical area, especially during cementation.
increase in length increases retention (3.0 mm increase In an effort to minimize the splitting potential of a
in post length enhances 40% of the retention). The tapered post, a flat surface is created at the occlusal
practical limitations, however, restrict the clinician to end of the preparation, which will resist apically
remain in the space properly surrounded by dentin. directed forces and prevent wedging. The proximity
The length of the post can be increased as far as possible, of the apical end of a parallel post to the periphery of
provided the post all around its length, should be root canal may increase the danger of a lateral
encircled by a minimum of 1.0 mm of dentin (Fig. 22.11). perforation, since the amount of dentin at the periphery
The remaining gutta-percha length at the apical end of apical end of post would be much less. A combination
should be 3.0–7.0 mm, depending upon the length of of parallel and tapered posts (cervical half of the post
root. During removal of gutta-percha, as the apex is parallel and the apical half-tapering) is designed to take
approached, the possibility of dislodging the root canal advantage of the parallel post and to minimize the
filling increases. The probability of uncovering the complications at the apical end (Fig. 22.13).
unfilled accessory/lateral canal increase, which may
lead to reinfection. Above all, the requisite 1.0 mm of
dentin may not be available at the apical end.
It is generally accepted that the length of post should
be more than the crown, preferably one and a half-time
the length of the crown. The post can be kept half-way
between alveolar crest and root apex. Shorter posts
besides being less retentive, may lead to fracture of root.
If the end of the post is at or above the alveolar crest of
bone, the part of the root investing the post uncovered
by bone will not be able to transmit forces from post to
tooth. The occlusal forces can produce stresses in the
unsupported root, fracturing it diagonally from tip of
the post down to the crest of bone.

Fig. 22.12 Parallel post

Fig. 22.11 Adequate post length Fig. 22.13 Combination of parallel and taper post
22

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 384 Essentials of Endodontics

3. Post Diameter
The diameter affects both resistance and retention of
the restoration. The smaller diameter post may get
displaced or fracture. Enlarging the diameter is not the
safest way of improving retention because it does
destroy dentin and weaken the root. The width of the
post should not exceed one-third the diameter of root.
1.0 mm of dentin thickness around the post (the mesio-
distal diameter of an average root is 3.0–4.0 mm at the
apex) should always be preserved (Post should be one-
third of the root diameter).
4. Surface Texture
The surface texture of the post (smooth, serrated or
threaded) plays an important role in the retention.
Threaded posts have been reported to be the most Fig. 22.14 Vent on one side of post
retentive. The pretapped, parallel-sided threaded posts
are approximately twice as retentive as a parallel-sided The 4-meta adhesives have the ability to adhere to tooth
serrated post and approximately six times as retentive structure as well as metals, resins and porcelain.
as a smooth sided tapered post. The smear layer should be removed from the walls of
Threaded posts, however, do generate stresses. the canal to open the dentinal tubules so that the cementing
Tapered threaded posts are more damaging because medium could flow into the tubules aiding mechanical
of the combination of a taper and threads. Posts with lock. It is recommended to use 17% EDTA followed by
serrated walls, which may and may not engage the sides irrigation with 5.25% sodium hypochlorite to flush away
of the canal are more retentive than the smooth surface the decalcified dentin and the remaining organic material
post. Surface treatment of posts such as sandblasting, from the root canal before cementing the post.
cleaning with hydrofluoric acid do aid in retention.
Sandblasted prefabricated posts provide better Clinical Procedures
retention than non-treated posts.
The clinical steps involved in preparation of postcore
5. Cementing Medium are as follows.
Several types of luting cements have been used for the
1. Removing the Gutta-percha
placement of posts in the canal. Zinc phosphate cement,
polycarboxylate cement and glass-ionomer cement The first step in postpreparation is precisely removing
are being used in routine. All cements are good in the gutta-percha up to the predetermined length without
compressive strength, fairly good in shear strength but disturbing the apical seal. Obturation techniques with
poor in tensile strength. Resin cements may provide gutta-percha include cold lateral compaction,
improved tensile strength. compaction of heat-softened gutta-percha, injecting
It is established that there is hardly any significant thermoplasticized gutta-percha (Obtura), placing gutta-
difference in retentive ability amongst routinely used percha in the canal and softened by mechanical means
cements; however, resins cements are more retentive (Mc-Spadden) and heated gutta-percha surrounding a
than other cements. plastic/metal carrier (Thermafil). Gutta-percha can be
A vent is created on one side of the post to relieve safely removed from the root canal in every technique,
hydrostatic pressure. This may be in the form of a except in Thermafil (such a technique is avoided in cases
V-shaped groove or a flat side on the round post where postplacement in anticipated). The pertinent ques-
(Fig. 22.14). Hydrostatic pressure can lead to bouncing tion is whether gutta-percha should be removed immediately
of post or even lead to fracture of root. after the obturation or after a gap of some time. A few authors
The new adhesive bonding agents are now being observed no difference in immediate or delayed removal
used for postretention. The 4-META product, C and B of the gutta-percha; however, it is advisable to remove
metabond have been found to be significantly superior the gutta-percha within 24 hours. The gutta-percha

22 in retention as compared to other bonding adhesives

(Panavia, Gluma, Mirage Bond, Scotchbond, Tenure)
as well as glass-ionomer and zinc phosphate cements.
becomes brittle as the time passes and the removal would
be difficult. More so, the apical seal is less disturbed if
gutta-percha is removed within 24 hours.

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 Postendodontic Restorations 385

The gutta-percha removal is facilitated by following

methods:
i. Thermomechanical removal: The gutta-percha
removal is initiated using small round bur. The
coronal/cervical 2.0–3.0 mm of gutta-percha should
be removed rotating the round bur in slow motion
(Fig. 22.15a to e). After the initial removal, bur
should not be used in the root canal; otherwise the

Fig. 22.16 Removing gutta-percha with warm file

direction of the bur may lead to deviated track. A

gently warm file is inserted in the gutta-percha and
a b
allowed to stay till it cool down (Fig. 22.16). The
file is then rotated anticlockwise removing the
entangled gutta-percha. The process is repeated
till the gutta-percha is removed up to the desired
length.
ii. Chemical removal: In case the gutta-percha is
brittle, dissolving agents can be used to soften the
gutta-percha. The commonly used solvents are
euclyptol, halothane and turpentine oil. The
chloroform being carcinogenic, is not used these
days. Turpentine oil is less toxic but it may lead to
dimensional changes in the gutta-percha, subse-
quently increasing the possibility of microleakage.
c Commercial preparations as Endosolv-R is used for resin-
based sealers and Endosolv-E is used for eugenol-based
sealers around the gutta-percha.
iii. Thermal removal: A heated instrument (say plugger)
is inserted into the root canal in a predetermined
length; it softens and removes the gutta-percha. A
system B spreader/plugger with a stopper is
inserted into the root canal at pre-determined
length, heated (up to 200°C) and kept for 3–5
seconds. The plugger is then twisted facilitating
removal of gutta-percha. Another plugger
(Buchanan plugger) can be used to compact the
gutta-percha at the apical end. The thermal
d e
technique, though good for wider canal, pose
difficulty for narrow canals.
Fig. 22.15 (a) Fractured central incisor; (b) Preoperative
radiograph; (c) Use of round bur (initial removal of gutta- 2. Preparation of Postspace
percha); (d) Radiograph after removing coronal gutta-
percha; (e) Radiograph after removing gutta-percha from
the root canal
Various instruments are being used for preparing the
postspace. The initial preparation is carried out using
22

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 386 Essentials of Endodontics

long shank burs and reamers. Non-end cutting, slow

speed instruments are preferred. Care should be taken
not to disturb the apical seal while using rotary instru-
ments (rotary instruments should be avoided especially
in apical-third area). Iatrogenic perforations generally
arise from use of end-cutting burs, failure to appreciate
root anatomy and use of incorrect angulations.
The appropriate sized Gates glidden drill is used in
straight and small canals. The final preparation should
be completed with appropriate Peeso reamers.
In order to distribute stresses properly and also to
avoid counter sinking of the post, a keyway is prepared
in the root canal (Fig. 22.17a to c). In case of posterior a
teeth, two root canals should be taken to avoid rotation
and to distribute the stresses properly (Fig. 22.18a to e).
The prepared postspace is washed thoroughly using
3.0% hydrogen peroxide followed by normal saline.
The prepared postspace should not be left empty for
long. This may result in accumulation and reactivation
of microorganisms in the postspace. In case the

b c

d e
Fig. 22.18 (a) Maxillary first premolar (failed root canal
treatment; one post for two root canals); (b) Preoperative
radiograph; (c) Single post; (d) Two post; (e) Postoperative
radiograph

impression making procedure is to be delayed, the said

space should be properly closed using paper points and
temporary dressings.

22 b c
Fig. 22.17 (a) Preparation of keyway (diagrammatic); (b) Wax
pattern showing keyway; (c) Casting showing keyway
In order to avoid perforation during preparation of
root canals, it is recommended that the post diameter
should not exceed one-third of the mesiodistal width

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 Postendodontic Restorations 387

of roots. It is hypothesized that post diameter of preparation of maxillary anterior teeth, care should be
0.7 mm for mandibular incisors and 1.7 mm for taken not to injure patient’s tongue, as melted wax may
maxillary incisors is sufficient and adequate. It is fall over the tongue. Either a piece of cotton or operator’s
important that the post diameter at the midpoint should left thumb should be kept under the core during
be 2.0 mm less than the root and at least 1.5 mm less at manipulation (Fig. 22.19a to f).
the apical tip area. In case the impression is made in resin, the plastic
pin is preferred. Ready-made plastic pins are available;
Postspace preparation: Safety features alternatively, a blade of comb can be guided to make it
• Postplacement should be limited to a depth of 7.0 mm apical round and can be used as a pin. Acrylic resin is coated
to the canal orifice over the plastic pin and inserted into the canal. Make
• Post diameter should be selected according to width of root/ the pin stable for a couple of minutes and then the pin
root canal
along with the resin is taken out (Fig. 22.20a to f). It is
• Only no. 2 peeso reamer should be used to prepare the canal
checked for any voids or discrepancies and if found so,
(No. 3 and 4 may lead to perforation)
• Mesial roots of mandibular molars and buccal roots of
the process is repeated. The resin can be manipulated
maxillary molars should be avoided, because the root surface easily in the mouth without being distorted. The core
facing the furcation is the common site of perforation is built over the post using the same resin.

Postspace preparation: Key features

• Use of non-end-cutting instruments, especially rotary
• Minimal canal enlargement
• Length to be decided on the basis of post material
• 4.0–5.0 mm gutta-percha should be retained at apical end
• Diameter should be one-third of the width of root
• Adequate space for ferrule
• Care should be taken not to lose the path

3. Impression Making of the Postspace

The impression making of the postspace is carried out
in custom cast post system to fabricate metal post.
The techniques utilized in impression making are:
i. Direct method
ii. Indirect method
Fig. 22.19a Roughening the needle
i. Direct method: The postimpression is fabricated
directly from the prepared space using resin or wax
pattern.
For making an impression, the selected pin (may be
plastic or metal) is roughened with carborundum disc.
Alternatively, an old file or reamer can be used. A thin
layer of sticky wax is applied over the pin. The apical
end should be properly covered by sticky wax. The pin
with sticky wax is tried in the root canal. The instrument
should be free in the root canal including the apical
end. If not, the smaller diameter instrument is tried
following the same protocol. Once tried, the instrument
is coated with blue inlay wax, gently warm and inserted
into the root canal. Keep it in the root canal for
60 seconds and then gently withdraw the instrument.
The ‘post’ impression is ready. Check carefully for any
voids, breakage and also the apical end. The process
can be repeated, if need be. The ‘post’ is inserted back
and the core is built in patient’s oral cavity using blue
inlay wax. While using blue inlay wax during core Fig. 22.19b Applying sticky wax
22

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 388 Essentials of Endodontics

Fig. 22.19c Inserting into postspace Fig. 22.19f Core fabrication

Fig. 22.19d Applying blue inlay wax and inserting again Fig. 22.20a Plastic pin

22 Fig. 22.19e Taking out the pattern Fig. 22.20b Applying acrylic resin

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 Postendodontic Restorations 389

Fig. 22.20f Final impression

ii. Indirect method: The post is fabricated from the cast.

To prepare the cast, the impression material
Fig. 22.20c Taking pattern (preferably rubber base) is injected into the canal. The
use of lentulo spiral ensures the elimination of
entrapped air in the impression material inside the
canal. The impression should be reinforced with some
type of rigid material, viz. steel wire, plastic pin or a
root canal instrument. The reinforcing devices not only
strengthen the impression during fabrication, but also
during pouring and separation.
The cast with prepared space for post is lubricated
by applying machine oil or cocoa butter. The impression
is made using blue inlay wax along with metal pin as
described for direct methods. The indirect method saves
time of the operator since, the impression can be made
by some assistant in the clinic or laboratory.

Ferrule Effect
One major complication of the post-restored tooth
is fracture of the root. The postcore should be so
Fig. 22.20d Impression on the cast
designed, that it should minimize the chances of root
fracture.
A ‘ferrule’ is a metal ring or covering around the
coronal part of the root intended for increasing the
resistance form. The word originates from combination
of two latin words ‘ferrum’ (iron) and ‘viriola’ (bracelet).
A dental ferrule is an encircling band of cast metal
round the coronal surface of the tooth. It can also be
defined as ‘the 360° metal collar covering/surrounding the
parallel walls of the dentin extending coronal to the shoulder
of the preparation’. The ferrule resists all types of stresses,
viz. functional forces, wedging effect of tapered posts
and the lateral forces exerted during the post insertion.
During functional movements (the forward
movement of mandibular anterior teeth Fig. 22.21), the
forces exerted on the core portion of the post and core
create pressure on the palatal surface of the root at the

Fig. 22.20e Taking impression with blue inlay wax

apical end of post. This process may lead to fracture of
root (Fig. 22.22a and b). To increase resistance of the
root to such fractures, the core portion is made to
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 390 Essentials of Endodontics

Fig. 22.23 Full veneer crown provides ferrule effect (crown

ferrule)

Fig. 22.21 Functional movement of mandibular anterior

teeth

Fig. 22.24 Location of ferrule

a b

Fig. 22.22a and b Functional forces on core (arrow),

required. The combined effect provides the requisite
pushing the post tip palatally (arrow) resistance to fracture of the root and/or postcore
restorations. The cervical collar along the core increases
encircle the root/remaining crown, so as the forces the resistance of the post and core to torsional forces).
generated on core may dissipate within the total root. The length/height of this covering is also important.
This covering of the core portion onto the root or crown The minimum ferrule length/height should be 1.5–2.0
portion is known as ‘Core ferrule’. The full veneer mm while restoring maxillary anterior teeth (Fig. 22.24).
crown over the core along with coronal tooth provides The fracture resistance is increased with the increase
ferrule effect, known as ‘Crown ferrule’. In case the in ferrule length/height. Ferrule width is also an impor-
length of the remaining crown is sufficient, there is no tant parameter; 1.5 mm width of the remaining dentin
need to have additional core ferrule effect (the coronal thickness is considered adequate and can provide
portion of the remaining tooth would bear the forces requisite 1.5–2.0 mm width of ferrule (Fig. 22.25a and b).
generated by the functional movements as in normal Many a times, clinical conditions warrant thinning
tooth). The restored crown in such cases will be of dentin wall around the root canal and the remaining

22 sufficient to provide ferrule effect (Fig. 22.23). In case

the dislodging forces are severe in nature (traumatic
deep bite, bruxism etc.), additional core ferrule may be
crown portion (the walls are considered ‘too thin’ when
they are less than 1.0 mm in thickness). Covering of
metal core over this thickness might not be practicable.

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 Postendodontic Restorations 391

a b

Fig. 22.25 Design of Ferrule (Diagrammatic representation) (a) Depth/width of Ferrule; (b) Ferrule width and remaining
dentin thickness

In such cases, ferrule effect is achieved only by the full

veneer crown.
The longevity of the restored endodontically treated
tooth depends upon the presence of adequate height
(1.5–2.0 mm) of sound tooth structure (ferrule), between
the core and the crown margins. The ferrule provides
the necessary bracing action to protect the integrity of
the root. Inadequate ferrule may lead to root fracture,
post fracture and/or loosening of post due to cement
failure.
The ferrule effect is divided into two: ‘complete
ferrule effect’ and ‘partial ferrule effect’. In case it is
practically feasible to encircle 1.5–2.0 mm of the coronal
tooth structure with the core, it provides ‘complete
ferrule’ effect (Fig. 22.26). Alternatively, covering only
the side walls with core may provide 'partial ferrule' Fig. 22.26 Core ferrule—complete
effect (Fig. 22.27).

Core ferrule: Key features

• The remaining dentin thickness should be at least 1.5 mm.
• The number of remaining dentin walls; preferably three or at
least two wall must be present; if only one wall is left,
alternative treatment planning, such as crown lengthening or
orthodontic extrusion is planned.
• Excessive lateral forces need more of remaining tooth structure.
• 1.5–2.0 mm covering is adequate.
• Core metal encircling completely, i.e. 360° (complete ferrule);
core metal encircling partially, i.e. 180° (partial ferrule)

In critical conditions where there is insufficient

crown structure for achieving ferrule length, the
clinician may consider crown lengthening procedures
(Fig. 22.28a and b) or orthodontic extrusion (Fig. 22.29).
This will allow the distance between crown margin and
alveolar crest to be widened and increase the potential
ferrule length. However, these methods may result in Fig. 22.27 Core ferrule—partial
22

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 392 Essentials of Endodontics

II. FIBER POSTS

The metal post and core provide optimum strength;
however, need for color masking and discoloration of
crown/gingiva with time, are the significant draw-
backs. Furthermore, metal shines through all ceramic
restorations and negates the transmission of light.
In an effort to overcome the disadvantages of metal
posts, fiber reinforced posts have been developed and
are widely being used as posts.

A. Custom Fiber Post

The fiber (plastic) post can be fabricated in clinics;
however, prefabricated posts are preferred.
Fig. 22.28a Preoperative The steps employed in fabrication are (Fig. 22.30a to h):
• The root canal configuration is evaluated clinically
and radiologically (Fig. 22.30a and b).
• Plastic pin of appropriate size is selected (plastic pins
are available; alternatively, a blade of comb grinded
to round shape can be used) (Fig. 22.30c).

Fig. 22.28b Crown lengthening procedure

Fig. 22.30a Preoperative

Fig. 22.29 Orthodontic extrusion

reducing the root length and making the crown-to-root

ratio unfavorable. In such cases fiber postcores are
preferred. The ferrule effect is not necessary in case of
fiber posts (fiber posts provide monobloc effect within
the root, substituting the ferrule effect). Thus balance

22 is mandatory between the ferrule length achieved and

the remaining root length. These considerations
determine the choice of post and core material. Fig. 22.30b Evaluating root canal

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 Postendodontic Restorations 393

Fig. 22.30f Curing outside the canal

Fig. 22.30c Selection of plastic pin

Fig. 22.30g Conditioning inside the canal

Fig. 22.30d Applying bonding agent

Fig. 22.30h Core build up

• The selected pin is roughened using old carbide burs

22
or used carborundum discs.
Fig. 22.30e Composite resin coated over the pin and • Bonding agent is applied over the prepared plastic
inserted into the canal pin (Fig. 22.30d).

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 394 Essentials of Endodontics

• Composite resin is coated over the plastic pin and

inserted into the root canal (lubricant is applied
inside the canal) (Fig. 22.30e).
• The pin along with composite is removed when
partly set and examined for any voids or irregula-
rities; if so, the process is repeated (Fig. 22.30f).
• The partially set composite is cured outside the canal.
• The inside of the canal is ‘conditioned’ and the primer
is applied (Fig. 20.30g).
• Flowable dual-cure composite is injected into the root
canal and the pin coated with same resin is pushed
into the canal. The material is cured from the coronal
end.
• After curing and setting, the core is built with
a
composite resin (Fig. 22.30h).
• The core is trimmed according to the anatomy of
crown.
• Veneer crown of choice can be placed over the
prepared core.

B. Prefabricated Fiber Post

A variety of fibers singly and in combination are being b
marketed as prefabricated fiber posts. Their classifica-
tion is described earlier; the properties and technique
of use is explained.
The commonly used posts, their properties and
technique of use is described.

a. Carbon Fiber Posts

Carbon fiber posts (Mirafit carbon, Endopost, etc.) are
considered viable alternatives to metals when proper-
ties like strength, stiffness, lightness and resistance to
corrosion and fatigue are compared. The carbon fiber
posts can bond to tooth structure and the modulus of
elasticity (rigidity) is similar to dentin (significantly
more flexible than metal posts). The carbon fiber posts c
are black in color and are radiolucent, which make it
difficult to detect radiographically (Fig. 22.31a to c). Fig. 22.31a to c Carbon fiber post
Replacing carbon with quartz fibers result in a tooth
colored posts. composite, creating initial shape of the core. The core
Technique portion is cured for 40 seconds. Finally trim and contour
The suitable sized post is selected according to the the core according to anatomy of the crown.
configuration of the postspace prepared. Advantages
The inside of the canal is etched with 37% phosphoric • Superior mechanical properties
acid for 10–15 seconds. The canals are washed • Modulus of elasticity is similar to that of dentin
thoroughly and dried with paper points. The primer is • Sufficient bonding to tooth structure and core
applied inside the canal and light cured. Similarly composite.
primer is applied to the post and light cured. The dual
Disadvantages
22 cure resin cement is applied inside the root canal and
the post is inserted with gentle pressure. The exposed
area of the post is coated with bonding agent and
• Unesthetic (black color)
• Radiolucent.

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 Postendodontic Restorations 395

b. Silica Fiber Posts polymerization of resin cement. A new fiberoptic

Silica fiber posts are either of quartz fibers or glass fibers. post, iLumi, was introduced, which can transmit
light up to 12 mm into the postspace, thereby
i. Quartz fiber post: The quartz fiber posts are the improving the retention of post.
improved version of the carbon fiber posts. The types
of quartz fiber posts are: Advantages
 Light post/DT light post/DT light safety post: These are • Radiopaque (allow postoperative evaluation).
available in different tapered designs for better • Modulus of elasticity is similar to that of dentin;
adaptation to the prepared root canal. They are reduces the risks of tooth fracture.
20.0 mm long, available in three diameters (0.9, 1.0 • Complete and non-traumatic removal is possible.
and 1.2 mm at the apex) and three tapers, 0.06, 0.08 • High tensile strength and superior fatigue resistance.
and 0.10. The matched set of reamers/drills is • Bond well to the tooth and core material.
available to prepare the postspace (Fig. 22.32).
Micromechanical tags are provided on the surface ii. Glass fiber post: The glass fiber posts are improved
of the posts for better retention. The post has a version of the quartz fiber posts. The glass fiber posts
modulus of elasticity similar to that of dentin; are esthetically pleasing along with maintaining the
functional stresses get dissipated and not properties of fiber posts (glass fibers have lower
concentrated in the root, subsequently reducing the modulus of elasticity than carbon/quartz fibers)
potential for root fracture. The translucent posts (Fig. 22.33a and b).
transmit light to the apical end and therefore may The types of glass fiber posts are:
be used with light or dual cure cements. • Lucent anchor post: The Lucent anchor post is
A retrieval kit for postremoval is available separately. designed to transmit natural tooth colors for esthetic
 Aesthetic/Aesthetic plus post: The posts utilizes white purposes. It is available in three diameters with 30°
quartz fibers surrounding carbon fibers (aesthetic tapers. The lucent anchor post can be easily removed
post) and all white quartz fibers (aesthetic plus). The in case of retreatment.
posts have high flexure strength and low modulus • FiberKor post: The bundles of glass fibers are
of elasticity as good as carbon fiber posts. impregnated in resin matrix, which provide the
The technique for placement of quartz fiber post requisite white color of the post. The post is available
is similar to that of carbon fiber posts. in four diameters and three degree taper along with
 iLumi fiber optic post: A post having ability to transmit matching drills (diameter 1, 1.2, 1.4 and 1.6 mm).
light to the most apical part of root canal space • Fiber white parapost: The post is parallel and has color
improves postretention. When light is transmitted coded ring around the head for identification. These
through root canal, its intensity is significantly are available in 4 sizes (diameter 1.14, 1.25, 1.4 and
reduced (less than 40%), subsequently decreasing the 1.5 mm).

22
a b

Fig. 22.33 Glass fiber posts: (a) Tenax fiber glass (outer);
Fig. 22.32 DT light post (b) Tenax fiber glass (inner)

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 396 Essentials of Endodontics

The glass fiber posts are virtually radiolucent; a few

contain silicone dioxide to impart radiopacity to the glass
fiber posts. A new glass fiber post, AR glass fiber post,
was introduced having radiopacity greater than
enamel/dentin because of addition of zirconium oxide
into the glass framework. A radiopaque post is preferred
because it provides an easy evaluation at the interface
with the root canal space.
The technique for placing glass fiber post is similar
to that of carbon fiber posts.

Advantage of fiber posts

• Adequate bonding with the root dentin (bonding provides
monobloc effect).
• Retentive; microretention achieved with fiber posts is far
superior to other posts.
• Fiber posts are minimal invasive; one-half the length of root
is sufficient as compared to metal posts where ‘length’ provides
retention.
• Parallel posts or half-parallel-half-taper as envisaged in metal
posts mandatory for retention and stress distribution is not
required in fiber posts. Small taper posts provide good retention Fig. 22.34 Ribbond—polyethylene fiber
and good potential for distribution of stresses.
• Metal posts exhibit corrosion potential, which may contribute Technique
to decementation and even root fracture. Fiber posts overcome The steps involved are:
the problem of corrosion (titanium and ceramic also do not
corrode). • The obturated material is removed up to pre-
• Removal of fiber post is easy, without disturbing the dentin
determined length (leaving gutta-percha at the apical
substrate. end) as described earlier. The natural internal form
• Fiber posts are more fatigue resistant. Fiber posts may flex of the pulp space is maintained. The final depth of
slightly, when necessary; some fiber posts have greater flexure the postdepends on the shape and diameter of the
strength than stainless steel and titanium. root canal. For single rooted teeth, the greater the
• Most of the fiber posts are radiopaque. irregularities and undercuts in the canal, the less
• Fiber posts (except carbon fiber being black) are esthetically depth of the post is required. For multirooted teeth,
pleasing and overcome the need of applying masking over the greater the divergence of the canals, the less depth
the post. of the post is required.
Disadvantages of fiber posts • Verify the removal of gutta-percha/obturated
• Fiber posts may undergo degradation because of repeated material by evaluating radiograph of the prepared
mechanical loading and under conditions of moisture. canal.
• Degradation may lead to a reduction in the modulus of • The margins of the coronal opening of canal are
elasticity and flexural strength with an increased risk in
debonding.
rounded to eliminate sharp angles between the post
and core; minimizes stress concentration and cracks
c. Polyethylene Fiber at the post and core junction.
Polyethylene fiber is available as Ribbond and Ribbond- • Measures the depth of the prepared canal with a
THM (Thinner Higher Modulus). It is used both as post periodontal probe. Different thickness of Ribbond is
and core material. Ribbond—THM is made of thinner available depending upon the need (for narrow
fibers with a higher thread count and is almost half as canals, thin Ribbond is preferred). Cut a piece of
thick as original Ribbond. Fibers are composed of Ribbond measuring twice the depth of the prepared
woven polyethylene (Fig. 22.34). The modulus of canal and three to four times the height of the

22 elasticity of these fibers is similar to that of radicular anticipated core. Use the widest Ribbond that will
dentin; suitable for fabrication of post and core as one fit in the canal in a double thickness. The greater mass
unit. of Ribbond fibers is preferred.

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 Postendodontic Restorations 397

• The canal is dried and etched for 10–15 seconds. • The Ribbond post along with resin adapts to the
Thoroughly rinse the canal and remove excess irregularities and undercuts within the root canals
etchant. Apply primers and adhesive inside the root and becomes retentive and anti-rotational after
canal using a microapplicator. curing.
• Wet the Ribbond with unfilled adhesive resin. • Since Ribbond post adapts to the irregularities and
• Carry dual/self-cure luting composite in a small is bonded to the tooth, it acts to cross-splint the tooth.
syringe, such as Endo-Eze or a Centrix syringe and The wedging effect, subsequently leading to root
place the syringe tip at the apical end of the canal fracture, is avoided.
before injecting the luting composite. Start injecting • Ribbond post and core do not require additional
the composite slowly while withdrawing the syringe. preparation after root canal treatment, which
Apply composite over the wet Ribbond also. eliminates possibility of root perforation.
• Ribbond is pushed into the apical end of root canal. d. Fiber Post with Gutta-percha
If space permits, insert an additional piece of wet
Ribbond into the canal, even if second piece could Fiberfill post system: The fiberfill system implies
be inserted half the depth of the canal preparation. simultaneous obturation of the prepared root canal with
The first piece is sufficient for retention of the post. the insertion of fiber reinforced post system. The system
The purpose of the second piece is to produce a consists of an adhesive bonding agent, a light-curable
greater density of Ribbond at the postcore junction. calcium hydroxide based resin sealer and a fiber post
The free ends emerging from the canal will be used with an apical terminus of gutta-percha. The primer in
to form the core. Do not cure till now. the system is a two-fold self-etching and priming liquid
that allows the sealer to chemical bond to the root
• After placement of the Ribbond in the canal, remove dentin. This system is time and cost-effective.
the excess flowing composite with a disposable
The main component and shape of some commercially
brush. Complete the core build up using appropriate
available fiber posts are summarized in Table 22.1.
resin. Finish and shape the core using diamond
rotary instruments. If the Ribbond becomes exposed
III. ALL CERAMIC POST
and fuzz, place a layer of unfilled bonding adhesive
over the exposed fibers and cure it. The major advantage of an all-ceramic post and core is
its dentin like shade. The dentin like shade of ceramic
Advantages postcore is related to the deeper diffusion and
• A Ribbond post like a natural tooth is translucent absorption of the transmitted light in the ceramic mass.
and esthetically pleasing as compared to a metal post All-ceramic restorations transmit a certain percentage
that is opaque. of the incident light to the underlying core and post on

Table 22.1 Chemical composition and shape of routinely used fiber posts
Post (fiber) Main component Shape
Rely X Fiber Post (Glass fiber) Resin matrix Double tapered
FRC Post-Plus (Glass fiber) UDMA, TEGDEMA, Ytterbium trifluoride, Tapered
high dispersed silicon dioxide
GC Fiber Post (Glass fiber) Methacrylate Double tapered
Light Post (Quartz fiber) Epoxy resin Double tapered
DT Light Post (Quartz fiber) Epoxy resin Double tapered
Macrolock Illusion Post (Quartz fiber) Epoxy resin Tapered, spiral head serrations
Radix Fiber Post (Zirconium enriched glass) Epoxy resin Double tapered
DT Light Safety Lock (Preconditioned quartz) Epoxy resin Double tapered
Dentin Post-X (Glass fiber) Epoxy resin Tapered
Snowpost (Zirconia-rich glass) Epoxy resin Cylindrical
Refor-post (Glass fiber) BiS-GMA Serrated
Fiber-Kleer-Serrated Post (Glass fiber)
Composi-post (Carbon fiber)
BiS-GMA, UDMA, HDDMA
Epoxy resin
Serrated
Two-stage parallel 22

t.me/Dr_Mouayyad_AlbtousH
 398 Essentials of Endodontics

which it has been placed. Thus, with all-ceramic posts • Thicker posts (require additional removal of dentin)
and cores, the color of the final restoration will be • Bonding with root dentin may not be adequate.
derived from an internal shade of the ceramic post,
similar to the optical behavior of the natural teeth. In IV. DENTIN POSTS (BIOLOGICAL POST)
addition, a ceramic post does not reflect intensively
The dentin post is a newer concept in which the post is
through thin gingival tissues, and provides trans-
fabricated from the root dentin of the stored extracted
lucency in the cervical root areas. All-ceramic posts and
teeth. The extracted teeth, preferably incisors or single
cores provide an excellent biocompatibility and do not
rooted, are stored in Hank’s solution or other storage
exhibit galvanic corrosion.
medium. The root canal of the tooth to be restored is
The main obstacles for using ceramics, as post and prepared in routine. The cementum of the stored tooth
core materials are their low flexural strength and is grinded by copy milling technique preferably to have
toughness. High toughness ceramics, such as the glass two dentin posts; alternatively, the canal of the
infiltrated alumina ceramic, In-ceram, and the dense extracted tooth is filled with composite and the
sintered alumina ceramic, show a three to six times cementum is grinded to have single post (Fig. 22.35a
higher flexural strength and toughness than do and b). The shape of the post is fabricated according to
conventional feldspathic and glass ceramics (compost: the configuration of the prepared canal. The silicone
available in two sizes; 1.4 and 1.7 mm). Contemporary impression of the prepared canal guides the fabrication
zirconia powder technology contributes to the of the dentin post. The post is finally luted into the root
fabrication of new biocompatible ceramic materials
with improved mechanical properties, i.e. further
increase in flexural strength and toughness. The
zirconium oxide ceramic have shown promising results
for the fabrication of all-ceramic posts and cores.
Zirconium has several advantages over other
ceramics owing to fundamental differences in their
physical properties (ZiReal post is Zirconia ceramic
with a small titanium insert at the apical part). Zirconia
posts usually have smooth configuration without any
serrations or threads. It is not possible to build a core
of ceramic onto the zirconia ceramic post. Ceramic cores
are fabricated indirectly and luted over the protruded
end of the root.
The ceramic posts are inherently brittle. It is difficult Fig. 22.35a Cementum removed and tooth stored
to remove a fractured ceramic post. The modulus of
elasticity of these posts is equal to metals, which make
the post stiffer. The stiffer post produces more stresses.
Advantages
• Radiopaque
• Stiff and rigid
• Resistance to corrosion
• Biocompatible
• Esthetically pleasing (superior to metal posts).
Disadvantages
• Brittle
• Removal is difficult during retreatment
• Produce stresses, being stiff
• Not etchable (impossible to grind away the post)
• Core retention difficult; not possible to bond
22 composite core material to post
• Weaker than metal posts Fig. 22.35b Radiograph showing dentin post

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 Postendodontic Restorations 399

canal using adhesive luting agents. The core portion roots in molars, fabrication of a single piece post and
can be fabricated with composites and finally restored core is difficult. Therefore, a core with two or three posts
with full veneer crowns. should be employed. The postcore for a mandibular
The dentin posts have successfully been tried in molar is usually divided into mesial and distal segments
deciduous teeth and are also showing promising results (Fig. 22.36a to j). The maxillary molar postcore is
in permanent teeth. composed of labial and palatal components. The two
piece system is also known as ‘split cast metal post and
V. INTRARADICULAR REHABILITATION WITH LIGHT core’.
TRANSMITTING PLASTIC POSTS The two-pieces must be bound together and remain
Occasionally, the post space presents a problem in stable after insertion. The core can be made in two
routine postcore restorations, viz. flared canals, wider halves held together by interlocking keys and key holes
canal, internal resorption, and/or caries inside the root (interlocking is created by cutting a keyway/dovetail
dentin. In such cases, the tooth is internally rebuilt with in one-half of core pattern).
appropriate materials (composite, light cure glass-
b. Post-Inlay System
ionomer cement) to structurally reinforce the root to
retain a post and core. A clear plastic light transmitting Many a times, teeth restored with crown may require
post is introduced, which can transmit light to endodontic treatment. Removing the crown may lead
polymerize composite resin placed deeply. The to fracture of the coronal portion of tooth or the crown
composite acts as a dentinal substitute and rehabilitate or both. Long span bridges also pose difficulty in
the weakened roots. removal. In such cases, it becomes mandatory to initiate
The light transmitting posts are also indicated in case root canal treatment through the cast restoration.
of caries in the root dentin or trauma to the immature An endodontic access through a crown is often larger
incisors. The internal resorption or any other mis- because the crown obscures the morphology of the
adventure leading to such type of canal configuration, tooth and makes it difficult to locate the root canal.
warrant the use of light transmitting posts. After completion of the root canal treatment, the
remaining unrestored part can be restored using
Technique prefabricated post along with appropriate cores or only
The light transmitting plastic post (Luminex light the coronal part depending upon availability of the
transmitting post) is selected according to the internal remaining dentin. The access cavity portion can also
configuration of the root canal. The post is tried and be restored as inlay along with custom post in one unit.
adjusted in length. The internal root dentin is acid If a post with an attached inlay is fabricated, the
etched, rinsed and dried. A dual cured bonding agent combined restoration is retentive and also able to
is applied inside the root, air blown to make it uniform withstand laterally directed forces.
and cured. A microhybrid composite is injected into Because this restoration is a combination of a post
the canal and the light transmitted post is pushed into and an inlay, it is designated as ‘post-inlay’ system.
the uncured composite resin to its full depth. The light
transmitting post allows the passage of light through Postretrievability (removal of post during retreatment)
its body but does not bond to the composite material. The removal of post during retreatment of endodonti-
A hemostat is used to rotate and remove the light cally treated teeth always present great difficulties
transmitting post, leaving an ideal shape for post- because of risk of fracture/perforation of the root,
placement. Lucent anchor post of same matching size especially when the remaining root dentin is less.
can then be inserted and cured in routine. However, with the recent technical advances, these
sequelae have been minimized.
VI. MISCELLANEOUS SYSTEM
The features which influence removal of posts are:
a. Two Piece Custom Post • It is easier to remove tapering post than parallel.
(Split Cast Metal Post and Core) Similarly, passive post is easier to remove than active
For the restoration of anterior teeth and premolars post.
having straight canals, a single piece cast post is usually • The resins cement and glass-ionomer cement, being
used along with core of same alloy or any core material. more retentive, pose difficulty in removal than zinc

22
However, in case of molars or the key abutment teeth, phosphate cement and zinc oxide eugenol cement.
which require more resistance and retention form, two- • In case the coronal end of post lies above the orifice
piece post is recommended. Because of the divergent of the root canal, the removal is easy.

t.me/Dr_Mouayyad_AlbtousH
 400 Essentials of Endodontics

a b

Fig. 22.36a and b Postspace preparation of the mesiobuccal and distal canals

c d
Fig. 22.36c and d Post patterns for mesiobuccal and distal inside the canals

22 e f
Fig. 22.36e and f Post patterns for mesiobuccal and distal

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 Postendodontic Restorations 401

g h
Fig. 22.36g and h Adjusted mesiobuccal and distal post

Fig. 22.36i Cementation of the post Fig. 22.36j Cast metal crown

• Fiber posts are easy to remove; metal posts and Various materials have been used and are being used
ceramic are difficult to remove. as core without a post or along with the post. The
The details of postremoval techniques are described commonly used materials are:
in Chapter 36.
a. Amalgam
CORES Amalgam was the most preferred core material;
however, over the years, especially with the increasing
It is established that every endodontically treated tooth popularity of all-ceramic crowns, it is no longer
may not require a post. Most of the teeth, especially preferred. Pins are indicated for anchoring amalgam
the molars can be successfully restored without a post. in teeth with extensive coronal damage. Amalgam pin
The remaining tooth structure usually supports the cores are usually not employed for teeth where the
core, which is sufficient to withstand the occlusal appropriate dentin is not available.
forces. A coronal radicular amalgam postcore has also been
The post is considered when the remaining tooth employed; the pulp chamber along with 2.0–4.0 mm of

22
structure is not sufficient to support the core. Many a each canal is filled with amalgam (amalgapin used as
times, the cusps are destroyed and/or undermining of secondary retentive devices). The bulk of amalgam is
cusps warrants the use of posts along with core. utilized for strength and retention.

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 402 Essentials of Endodontics

The amalgam cores are usually given under metal

crowns or metal ceramic crowns.
Advantages
• Reduced marginal leakage
• Better dimensional stability
• Good compressive strength
• Good modulus of elasticity
• Manipulation easy. a

Disadvantages
• Safety issues with mercury use
• Corrosion with base metals
• Discoloration of gingiva and dentin.

b. Composite Resin
Composite resin cores can be used along with pins and
posts as well. They are quite strong and easy to
manipulate. The resin adapts well to retentive pins and
possesses as much tensile strength as amalgam cores.
Composites cores are recommended in teeth with
minimum tooth structure loss (Fig. 22.37a and b).
The disadvantage with composite core is that the
microleakage is greater than amalgam cores. Tensile
bond strength for cast crowns is less during cementa-
tion; however, the retentive capacity is adequate. The
crown margins should extend well past core margins. b
Lumiglass composite has been tried as core material. Fig. 22.37a and b Composite core material
Lumiglass core build-up composite is formulated to
optimize with fiber posts. Light cure Lumiglass Advantages
is translucent, and can be cured up to 8.0 mm thick- • Adhesive (chemical bonding with tooth)
ness. • Anticariogenic
Lumiglass exhibits good handling characteristic for • Manipulation easy.
easy manipulation. It is radiopaque, and has better
Disadvantages
physical properties. The esthetic neutral shade is ideal
• Low resistance to fracture
for use with all-ceramic crowns.
• Sensitive to moisture
Advantages • Solubility
• Easy manipulation • Low strength (fracture toughness).
• Good compressive strength
• Rapid/deep polymerization. d. Glass-cermet Cement
A combination of glass-ionomer cement and silver alloy
Disadvantages in the ratio of 7 : 1 has been used as a core material.
• Poor dimensional stability The glass-cermet cement possesses all the mechanical
• Polymerization shrinkage. properties required for core and additionally helps in
caries reduction by releasing fluorides. However, the
c. Glass-ionomer Cement black color of the glass-cermet limit its use only under
Glass-ionomer cement has also been used as core metal crown or metal-ceramic crowns.
material. It is preferred in cases where caries suscepti-
e. Resin modified Glass-ionomer Cement
22 bility is high and also in teeth with minimal tooth
structure left. However, it is avoided in teeth under
lateral load.
Composite resin in combination of glass-ionomer
cement has also been used as core material.

t.me/Dr_Mouayyad_AlbtousH
 Postendodontic Restorations 403

Advantages • Elimination of allergic reactions

• Anticariogenic • Good adhesive properties
• Sufficient strength for smaller cores • Radiolucent; facilitate caries detection.
• Good bonding Indirect composite resin over this material also act
• Minimal microleakage. as stress breaker and reduce the occlusal load.
Endocrown using PEEK materials have shown good
Disadvantage
retention and without any microleakage. The esthetic
• Expansion of cement may displace crown. appearance is equal to ceramics; however, intraoral
occlusal adjustments may lead to unesthetic appearance.
ENDOCROWN
Use of high-strength ceramics coupled with adhesive RESTORATION OF TEETH AFTER ROOT AMPUTATION
technology has resulted in restorative treatment In hemisection and radisectomy procedures, one
modality for posterior teeth without the use of post and root is extracted and the other root(s) along with
core. The term ‘endocrown’ was coined to describe a the trunk (mostly) is utilized for restoration purposes
ceramic crown extending into the pulp chamber/root (Fig. 22.38a to e).
canal orifices of the endodontically treated teeth in
order to gain retention. Indications for root amputation are:
Endocrown is indicated for teeth with short clinical • Severe periodontal involvement of the single root
crowns or calcified/curved canals where postcore • Severe furcation involvement
restoration is not feasible. These are also indicated in • Severe root caries/resorption inside the root, which
patients having limited interocclusal space, not cannot be treated
providing adequate thickness for both the ceramic • Endodontically unmanaged root (e.g. instrument
veneer and the metal/ceramic core framework. fracture, perforation, etc.)
It is established that endocrowns exhibit superior The restoration protocol differs in mandibular and
(higher) fracture strength than conventional postcore maxillary molars.
crowns.
Initially, endocrowns were fabricated using reinforced, Restoring Mandibular Molar
acid etchable ceramics because they provide adequate In mandibular molars, either mesial or distal root is retained.
mechanical strength to withstand occlusal load (ceramic a. Retaining distal root: In case the distal root is retained,
reinforced with lithium disilicate provide high mecha- it is advantageous being straight, has the widest canal
nical strength, excellent adhesion, and good esthetics). and can accommodate the deepest post. Being
posteriorly placed, it provides a greater arch length.
Advantages of Endocrowns It is wider in a buccolingual than mesiodistal
• Short preparation time direction and is handled like a bicuspid in its
• Less chair time preparation for post and core. When the distal root
• Easy manipulation has two canals, the distobuccal canal is usually the
• Esthetically pleasing larger and should receive the post. The orifice is
• Cost-effective. widened buccolingually to avoid perforation.
A composite resin foundation along with indirect b. Retaining mesial root: In case the mesial root is
composite resin crown has also been tried. Recently, a retained, the straighter mesial canal (mesiolingual
high performance polymer, polyetheretherketone canal) is prepared to hold a single post. Additional
(PEEK) containing 20% ceramic filler has shown retention may be gained by using a small preparation
promising results. The material exhibits superior at the orifice of the unused canal. This also provides
mechanical properties and is biocompatible. antirotational device for the post and core prepara-
tion. Because of the curved nature of these canals,
Advantages of PEEK care must be exercised not to make the posts so long
• Better modulus of elasticity (4 GPa—as elastic as that they deviate from the prepared canal space and
bone); act as stress breaker, dissipating occlusal load lead to perforation. Both mesial canals can be used
uniformly to tooth and the root. for twin posts. They must be parallel in the cervical
• Good wear resistance
• Polishability is good (not in oral cavity after occlusal
adjustments)
third of canal, if a cast post is used but can deviate if
fiber posts are used. Total retention is equal to the
sum of post lengths. The root is treated as a bicuspid
22

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 404 Essentials of Endodontics

a b

c d

Fig. 22.38 Hemisection of mandibular first molar: (a) Preoperative: badly mutilated mandibular first molar; (b) Hemisection
of molar; (c) Extraction of distal root; (d) Restoration with cast metal crown; (e) Radiograph showing final restoration
(postoperative)

and is prepared along with the adjacent tooth to proximal space where the furcation has been located.
receive a restoration in a bridge form. Minor orthodontic tooth movement can be helpful.
c. Bisecting mesial and distal roots (retaining both): In case The recontouring is usually accomplished in two
both the roots are retained, it is usually not possible phases:

22 to create a satisfactory environment for future

cleaning around both the roots. The two roots are
usually not divergent enough to gain a sizeable inter-
i. Initial contouring when the amputation is performed
ii. Final contouring during tooth preparation for
crown fabrication.

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 Postendodontic Restorations 405

The recontouring is mainly completed in first phase. buccolingually, which may place the occlusal table in a
The line angles are blended smoothly. Sharp projections cross-bite relation.
or spurs are eliminated. The interproximal areas
between the amputated root and adjacent tooth must CEMENTATION OF POSTENDODONTIC RESTORATIONS
be kept open to allow for optimal plaque control. The The postcore restorations and the indirect restorations
furcation area should be fluted to allow for proper tissue (onlays, full veneer crowns) are to be cemented over
adaptation. the cores prepared for such restorations. A variety of
In the final phase of recontouring, the occlusal table luting agents are available with varied advantages and
should be narrowed and the excursive contacts should disadvantages. The commonly used luting agents are:
be eliminated. • Zinc phosphate cement
• Polycarboxylate cement
Restoring Maxillary Molar
• Glass-ionomer cements
In maxillary molars, the root which most commonly • Resin modified glass-ionomer cements
needs extraction is the mesiobuccal root. The other roots • Resin cements.
are usually managed clinically. However, in certain
cases distobuccal root is also extracted along with the Requirements of a luting agent
mesiobuccal (palatal root is to be preserved for post The requirements of a luting agent are:
and core restoration). • Wettability: Seals the gap between restoration and the
tooth surface.
a. Retaining distobuccal and palatal roots: The channel
• Film thickness: An ideal film thickness is considered
for post is prepared in the palatal root. The areas
as 25 μ; depends upon viscosity of the liquid.
adjacent to the retained roots is critical because the
trifurcation formed by the missing and remaining roots • Flow: Ability to move into minor intricacies filling
may pose clinical difficulties. This area is prepared to the gaps; lower powder: Liquid ratio enhances flow.
prevent the residual furcation from acting as a shelf • Dissolution in oral fluids: Dissolution lead to marginal
for plaque accumulation. leakage; resin cements are less soluble followed by
glass-ionomer cements.
The preparation at the gingival margin resembles a
figure eight shape as the preparation is beveled in the • Should be biocompatible.
furcation area between the remaining two roots. The • Should be radiopaque.
shape of the final restoration at the gingival margin will • Sufficient strength to resist long-term fatigue stress
depend on the horizontal depth of the concavity created at the margins.
between the two roots. Flat contours with mild • Wear resistance: May lead to caries and unesthetic
concavities are preferred. The final coronal restoration appearance, if cement do not resist wear at the tooth-
should have an occlusal configuration similar to that restoration interface.
of a molar but with the mesiobuccal or distobuccal • Overhang control: Extra cement is to be cleaned
portion reduced to lessen the occlusal stress where no without disturbing the presence of luting agent at
root is present. At the gingival margin there is a large the margins.
embrasure where the amputated root was formerly
present. Clinical Aspects
The clinical aspect of cementation is important as many
b. Retaining palatal root only: Sometimes, both the factors play part in successful cementation of the restora-
buccal roots are extracted and only palatal is retained. tions. The cementation procedure is divided into two:
The palatal root is the widest of the maxillary roots and a. Seating
circumferential concavities on palatal roots are far more b. Retention
subtle than concavities on the other maxillary roots. The
single remaining root must be used in conjunction with a. Seating
another tooth/teeth, since, it is not strong enough to The discrepancies in the prepared tooth and the castings
function alone. The natural buccal curvature of the coupled with cementing pressure lead to rebound of
palatal root creates a severe undercut on its straight restoration. These discrepancies are to be compensated
buccal surface. A beveled shoulder preparation of the for proper seating of the restoration. The best method
buccal surface of the palatal root is required to parallel
it with adjacent teeth and allow preparation of the
undercut margin. The restoration must be narrow
is to coat the die with multiple coats of die-spacer.
Alternatively relieving the die or etching the casting
can be helpful.
22

t.me/Dr_Mouayyad_AlbtousH
 406 Essentials of Endodontics

In seating the cemented restoration, the following

features play important role.
i. Rheology of cement
ii. Working time
iii. Final film thickness
iv. Geometry of gap.
The failure usually occurs at cement-tooth interface.
The flow of cement is the key factor for successfully
cementing the restorations. To achieve sufficient cement
flow, it is to be loaded rapidly and steadily maintained,
until cement is set. The seating of restorations should
be completed within a few seconds while the cement is a
sufficiently fluid.
The correct mix of zinc phosphate, polycarboxylate
and ethoxy-benzoic acid cements has adequate flow
with moderate pressure. The resin cements are less
satisfactory in this respect.
The zinc oxide eugenol cement generates the lowest
hydraulic pressures during seating, followed by poly-
carboxylate cement. Zinc phosphate cement exhibited
the greatest hydraulic pressure. The tendency of
rebound will not occur in case the seating force is
maintained for sufficient time without any interruption b
while the cement is setting. Fig. 22.39 (a) Extra cement at the cervical end; (b) Over-
Mixing on a cool glass slab provide adequate hanging cement at the distal cervical area
working time.
The excess of cement is to be removed. In case of
postcore preparation, a sort of path is created, known
as ‘venting’ which facilitates easy removal of cement
and minimize the hydraulic pressure. Venting also
provide minimal film thickness under cast restorations.
All cements have overhang after seating of the
crowns or other indirect restorations (Fig. 22.39a and b).
The criteria of time as regard removal of the overhang
are very important. The ‘cleaning’ of set zinc phosphate
and polycarboxylate cements is comparatively easier
than glass-ionomers, composites and dual-cure
cements. In such cases the ‘cleaning’ is carried out
before the cement is set completely, i.e. partly set
cements. Once the ‘extra’ cement is cleaned from all Fig. 22.40 Gap at the tooth–restoration interface
the sides, the patient is again asked to press the
restoration. The pressing of restoration will fill the gaps b. Retention
between the tooth and restoration, if any. Once the
The luting agents do not help in retention directly;
cement is set, the probe should not be touched at the
however, the tensile strength of the cement does aid in
margins. Use of probe will remove the set cement,
longevity of the restoration.
subsequently leaving the gap for caries and sensitivity
(Fig. 22.40). The low viscosity luting agents should be The retention of the restoration mainly depends upon
used under easily accessible margins. Recently, the the following:
trend of using luting agents, which change color after i. The design of the tooth preparation, which in turn
influences the stress distribution.
22 setting is gaining importance. However, it is opined
that such color may damage the overall esthetic nature
of certain restorations.
ii. Bonding efficiency of the luting cement to both the
surfaces, i.e. tooth and the restoration.

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 Postendodontic Restorations 407

iii. Durability of the cement, which includes its long- 11. Chieruzzi M, Pagano S, Cianetti S, Lombardo G, Kenny JM
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titanium posts. Dent. Mater.: 2007; 23:138–144. Prothodont.: 2009; 18:464–472.
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22 48. Radovic I, Monticelli F, Goracci C, Vulicevic ZR and Ferrari

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Prosthet. Dent.: 2017; 117:335–339.

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 Chapter
23
Endodontic Emergencies

The word ‘emergency’ literally means any condition e. Crack tooth syndrome
which warrants immediate attention. Any biological f. Tooth fracture
condition usually of unforeseen and unscheduled i. Crown fracture
occurrence, requiring immediate management is • Enamel infraction
referred to as medical emergency. Endodontic • Uncomplicated crown fracture
emergency is defined as ‘pathology (pain, swelling, • Complicated crown fracture
fracture, avulsion, etc.) associated with pulp and periapical
ii. Crown and root fracture
tissues, which need immediate attention (diagnosis and
iii. Root fracture
treatment) to provide relief to the patient.’ Pain in the oral
cavity can have many causes although pulpal and • Transverse/horizontal root fracture
periapical diseases are the most common. Due to • Vertical root fracture
confinement of the pulp tissue in dentin, nature of g. Luxation injuries
inflammatory response of pulp is more severe, leading i. Concussion
to severe pain. ii. Subluxation
Prevalence of endodontic emergencies among all iii. Extrusive luxation
dental emergencies varied from 30 to 90%. The iv. Lateral luxation
emergency is mainly the pain for which patient seeks v. Intrusive luxation
immediate attention. The operator is to re-schedule the h. Avulsion.
appointments to accommodate the emergency patient.
2. Mid-treatment emergencies
The timely and quickly attention to such patients along
with alleviating the pain builds confidence in the a. Incomplete pulp tissue removal
patient. The confidence so developed is useful in further b. Apical periodontitis
planning and treating the problem. i. Due to over instrumentation
ii. Due to chemical insult
CLASSIFICATION c. Phoenix abscess (mid-treatment flare up).
The endodontic emergencies are classified as: 3. Post-treatment emergencies
1. Pretreatment emergencies a. Over instrumentation
a. Hyperreactive pulpalgia b. Over obturation/sealer extrusion
i. Dentinal hypersensitivity c. High restoration
ii. Hyperemia d. Root fracture.
b. Acute irreversible pulpitis
DIAGNOSIS
c. Acute apical periodontitis
The initial and provisional diagnosis is achieved early
d. Acute periradicular abscess
since, the patient is in agony of pain and need immediate
i. Abscess without swelling
solution for the same. Pain must be considered in terms
ii. Abscess with localized fluctuant swelling of quality (sharp, piercing, lancinating, dull, boring,
iii. Abscess with localized non-fluctuant swelling gnawing and excruciating). The commencement,
iv. Abscess with diffuse swelling duration, provocation (hot, cold, chewing or biting, etc.),

409

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relief and localization of pain should also be noted. ii. Hyperemia: Patient complains of shock sensation
These characteristics of pain and any associated which disappears on removal of the stimuli.
tenderness or swelling may be pathognomonic for Hyperemia implies increased supply of blood to the
specific conditions. The nature of the pain directs the pulp; may be due to caries, leaky restorations, high
operator to opt for either definitive treatment or restorations, finishing and polishing without
palliative treatment. coolant and also chemical cleaning of the cavity.
The medical history facilitates identifying the risk Teeth are not tender to percussion except when
patients (immunocompromised, hypertensive, allergic, occlusal trauma is a factor. Cold stimulates
diabetic, etc.) who may require a medical consultation, hyperemic pulp more readily than normal teeth.
premedication or modification of the emergency treat- Radiographic examination reveals normal perio-
ment. Palpation and light percussion helps to identify dontal ligament space and lamina dura.
periradicular inflammation. Periodontal probing and Treatment
pulp vitality test helps in differentiating pain, which • Causative factor is to be removed followed by
might be due to pulpal or periodontal origin. Response palliative treatment.
of patient on application of cold, heat, electricity and • Occlusion should be checked; recontour the high
direct dentin stimulation usually indicate the status points.
(vital or necrotic) of pulp. Additionally periapical and • Use pulp protection measures, such as, varnish,
bitewing radiography may detect depth of caries, bonding agent, liner or bases under restorations.
pulpal exposure, fracture, internal/external resorption,
• Placement of sedative dressing, such as, zinc
periradicular changes, etc.
oxide eugenol cement after removal of deep
1. Pretreatment Emergencies caries/any other irritant (usually from leakage).
• Microcracks, if detected and diagnosed, may be
a. Hyperreactive Pulpalgia treated with bonding and flowable composites.
The sharp pain of short duration in the absence of The pain gradually disappears once the causative
pulpal inflammation is termed hyperreactive pulpalgia. factor is removed. However, if pain persists,
This can be due to dentinal hypersensitivity or pulpectomy should be performed.
hyperemia.
i. Dentinal hypersensitivity: Patient complains of sharp b. Acute Irreversible Pulpitis
and short duration pain, initiated due to contact of Irreversible pulpitis is defined as ‘an inflammatory process
any thermal (usually cold), osmotic (sweet or sour), in which the dental pulp has been damaged beyond repair.’
electrical (galvanic current on contact of two The classical symptoms of irreversible pulpitis are
dissimilar metals) or physical (toothbrush, floss, intermittent/spontaneous pain (not of short duration),
interdental stimulator, fingernail or explorer) which lingers on and does not resolve even after
stimuli to the exposed dentin. Faulty brushing, removal of the irritant. The pulpal pain may be sharp
curettage, usage of high abrasive toothpaste, cracks, or dull, localized or referred, depending upon the type
etc. may lead to dentinal exposure. Clinically and of nerve fibers involved. Pain is often worse during the
radiographically, such abnormality is usually not night or on bending, because the recumbent position
detected. increases blood pressure in the pulp. Pulpal pain may
Dentinal sensitivity is due to the movement of be referred to adjacent teeth or even the teeth in
dentinal fluid leading to activation of nociceptors opposing jaw. Occasionally, momentary relief may be
in the inner dentin or outer pulp. provided by cold stimulus as vasoconstriction of the
Treatment dilated vessels reduces pulpal tissue pressure. Since
The treatment includes closure of open dentinal inflammation is mainly confined in the pulp, and peri-
tubules and use of agents that inactivate pulpal radicular changes might not be evident, the diagnosis
nociceptors. The iontophoretic application of of this condition becomes difficult. Pouring hot water
fluoride salts, complemented with fluoridated on the isolated tooth may help in diagnosis. On electric
toothpastes and mouth washes, etc. help minimizing pulp testing, less current may be required for response
opening of dentinal tubules. in early stages; whereas, more current is required when
Excitability of pulpal axons can be reduced by the tissue is necrosed. Differential diagnosis should be

23 potassium ions; use of toothpastes containing

potassium facilitate early closure of dentinal
tubules.
made between hyperemia and acute irreversible
pulpitis, as the former is reversible but the latter is
not.

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 Endodontic Emergencies 411

Treatment syndrome’ is mainly related to sensitization of nerve

The preferred treatment modality is the root canal fibers. Supplementary anesthesia in the form of intra-
therapy. The emergency procedure may depend upon ligamentary injection, intrapulpal injection, etc. can
the stage of root formation (open or close apex) in both be effective (after access cavity preparation).
single and multirooted teeth. • Corticosteroid dressing as suggested by few authors,
• In case of close apex, root canal treatment is preferred should be used sparingly; suppression of an
(may be completed in single visit). inflammatory response by steroid allows bacteria to
• In case of open apex, pulpotomy is preferred enter the bloodstream. This may be deleterious for
applying MTA or calcium hydroxide. certain patients having artificial valves, etc.
• In case of time constraints, emergency root canal • Close dressing should be preferred to avoid bacterial
opening (ERCO) is to be carried out followed by root contamination of clean canal. Occlusal adjustment
canal treatment later. to remove faulty contacts is often helpful. Relieving
occlusion reduces pain, especially in teeth which are
c. Acute Apical Periodontitis sensitive to touch.
This is an acute inflammation of the periodontal • Antibiotics for this condition have no role. Only in
ligament which may be associated with a vital or a non- the event of systemic signs or spread of the infection
vital tooth. Generally acute periodontitis is the into facial planes, antibiotic can be prescribed.
extension of pulpal inflammation; however, traumatic Routine analgesics can be effective.
occlusion, bruxism, sinusitis or orthodontic treatment
may also lead to acute periodontitis. Rarely inflamma- d. Acute Periradicular Abscess
tory reaction of the healing pulp may initiate perio- (Acute Alveolar Abscess)
dontitis. Acute periradicular abscess is also known as acute
apical pericementitis. It may develop as a succession
Signs and symptoms
of acute apical periodontitis, which is caused due to
Patient is presented with history of spontaneous, extension of pulpal infection into periradicular areas.
throbbing, sharp pain on exposure to thermal stimulus Acute abscess as an exacerbation of a chronic apical
and persistence of pain following removal of stimulus. periodontitis is referred to as ‘Phoenix abscess’.
Classical manifestation is, heat causes intense pain,
The concerned tooth is tender to percussion. On
whereas cold relieves the pain. Tooth is tender on
palpation it may show minor mobility due to extrusion
percussion (eating/biting on the affected side hurts).
from the socket (mobility depends upon the amount of
Clinical examination reveals tenderness in the buccal periapical exudates). Palpation may cause discomfort
sulcus on palpation. Presence of inflammatory exudates because of swelling, which may vary from undetected
in the periodontal ligament causes elevation of tooth swelling to gross cellulitis. Swelling can be diffuse or
from within the socket; leading to pain, whenever tooth localized and fluctuant or non-fluctuant. The tooth
comes in contact with the opposing tooth. usually does not respond to pulp vitality tests. The
Radiographical appearance may vary from small patient feels pain due to pressure build-up in the
periapical radiolucency, thickening of periodontal periapical area because of toxic products. The pain
ligament space to normal appearance. Occasionally all continues until the purulent discharge crosses the
the three conditions can be seen around a multirooted cortical bone and enters the soft tissue.
tooth.
The buccal vestibule is the most common site of
Treatment swelling; however, orientation of root apex and
• If the periodontitis is caused by extension of pulpal muscular attachment, etc. may deviate the location of
inflammation, the pulpotomy may not relieve the the swelling. Application of heat on that area may add
pain; root canal treatment is preferred (may be to discomfort due to expansion of gases.
compiled in single visit, or in case of time constraint/ The acute lesions usually do not destroy sufficient
patient’s long-sitting, multiple visit RCT is preferred). periapical tissue for radiographic visualization.
In case it is due to traumatic occlusion, selective Radiographically, the lesion may remain undetected or
grinding of the traumatic surface(s) will be sufficient. show only widening of periodontal ligament.
• When acute periodontitis is associated with mandi-
bular premolars and molars, achieving profound
anesthesia is difficult. The so-called ‘hot tooth
Acute periradicular abscess and acute periodontal
abscess is to be differentially diagnosed (tooth shows
positive vitality if the cause is periodontal).
23

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 412 Essentials of Endodontics

Treatment incision adequately. Copious irrigation with saline

The pulpal and periapical pressure is to be relieved and betadine should be carried out alternatively.
immediately by establishing drainage and opening of Sometimes effective drainage is established using a
root canals. The treatment protocol may be modified ‘drain’ (a sterilized piece of gauge or a strip of rubber
depending upon signs and symptoms of the case; the dam). Drains can be self- retentive (no need to suture
conditions described as follows: to hold) or non-retentive (suture to edge of soft
tissues to hold). Warm saline rinses are suggested
i. Abscess without swelling: As the tooth is nonvital, for at least 48 hours after the drainage process.
there is no need of local anesthesia. However, if patient Artificial fistulation can also be established by
has discomfort or for psychological reasons, block incising the most dependent point of the swelling.
anesthesia can be given. The access is achieved using The opening is enlarged with an excavator to
high speed instruments, minimizing vibrations. In facilitate the discharge.
restored teeth, the restoration is removed completely; Trephination is carried out only if drainage through
the access opening is evaluated and modified root canal and routine incision fails. Trephination
accordingly. Root canals should be thoroughly cleaned implies cutting a hole through cortical bone into the
of the necrotic substrate. Access to the pulp chamber cancellous space to relieve the build-up inflammation
and root canals will relieve the gases present. The pressure. Block anesthesia is preferred. The location
appropriate sized endodontic instrument can be of the nerves and other anatomic structure are to be
extended beyond the apical foramen to establish evaluated before incision. A horizontal incision
drainage. Once complete drainage is established, the should be made roughly in the middle to apical 1/3
root canal should be irrigated and dried, followed by of the root. An appropriate surgical bur is used to
dressing and temporary closure of access opening. The make a window in the cortical plate to locate the root.
occlusion should be relieved. Proceed apically until the apex is reached. Once
drainage is achieved, the apical area is curetted and
ii. Abscess with localized fluctuant swelling: In case
irrigated. Drain is placed and resorbable suture
of acute abscess with fluctuant swelling, immediate
should be placed to close the lateral extent of incision.
drainage is to be established, either through root canal
The drain is removed after 24 to 48 hours. In case of
or through soft tissues.
multiple abscesses, drainage is established both
• Drainage through root canal: The drainage of abscess through root canal and soft tissues.
through the root canal is a preferred treatment
modality. Block anesthesia is preferred, since local iii. Abscess with localized non-fluctuant swelling: The
infiltration is not indicated (may cause pain due to conventional root canal treatment is initiated and
the distended area). Access is gained with high speed drainage is established through the root canal. The
instruments, minimizing vibrations. An appropriate incision through soft tissues should not be tried, as it
sized endodontic instrument should be carefully may worsen the condition by spreading the infection.
extended beyond the apical foramen to establish The patient is advised to rinse continually with warm
drainage. A suction device can also be used. The root saline.
canals should not be left open to the oral environ-
ment as it may lead to severe contamination of iv. Abscess with diffuse swelling: In case of diffuse
microflora, including enteric bacteria and yeasts. swelling, the patient also shows other systemic signs,
Copious irrigation should be carried out while such as, fever, malaise, nausea, lymphadenopathy, etc.
cleaning the canals and even after till the drainage is These patients need immediate antibiotic coverage.
complete. The canals are dried, followed by dressing Root canal treatment can be initiated in case the
and sealing the access cavity. The tooth is dis- infection has not involved facial spaces; otherwise the
occluded. patients should be referred to a hospital till the infection
• Drainage through soft tissues: The drainage through is under control to carry out further procedure.
soft tissues is established either using routine incision In case sufficient drainage could be achieved, patient
or trephination. should be evaluated for next 24 hours and if symptoms
The area is anesthetized using block anesthesia. persist, the antibiotics can be prescribed.

23 Following routine protocol of incision and drainage,

incise the swelling from inferior side with sharp
scalpel blade. Hemostat can be used to open the
The effect of antibiotics, vis-a-vis patient’s condi-
tion and the status of drainage is summarized in
Table 23.1.

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 Endodontic Emergencies 413

Patient’s condition, status of drainage and effect Signs and symptoms of tooth tissue involved in
Table 23.1 Table 23.2
of antibiotics cracks
Patient’s condition Status of drainage Antibiotics effect Involved tooth tissue Sign and symptoms
No systemic Sufficient drainage Not required Enamel crack Asymptomatic
involvement achieved Crack involving dentin Pain on biting, specially on release
No systemic Insufficient drainage Partially effective of biting force, sensitivity to cold, etc.
involvement Crack involving pulp Symptoms related to pulpitis (e.g.
Systemic Sufficient drainage Partially effective sensitivity to both hot and cold,
involvement achieved referred pain, etc.)
Systemic Insufficient drainage Antibiotic required
involvement along the crack line, resulting in movement of the
dentinal fluid in the dentinal tubules. This movement
e. Cracked Tooth Syndrome stimulates odontoblasts in the pulp (crack line
The term ‘Cracked Tooth Syndrome’ refers to an extending to the pulp directly stimulates the pulpal
incomplete fracture of a vital tooth that involves the tissue). Patient’s history occasionally reveals repeated
dentin and occasionally extends into the pulp. The restoration or repeated occlusal adjustment of same
diagnosis of cracked tooth syndrome is usually difficult, tooth without relief of symptoms.
since radiologically only normal features are visible. The crown of tooth in doubt is painted with tincture
The early detection of cracks is important, because with iodine or methylene blue dye which is washed after
passage of time the cracks progress and may lead to two minutes. The crack will appear as dark line. Use of
bacterial invasion. magnification can be a useful aid. Use of a fiber optic
light often reveals the position of the crack. On
Etiology
periodontal probing, a narrow pocket may be located
The etiologic factors are: adjacent to the fracture site. Occasionally a sinus tract
• Trauma can be appreciated, which can be closer to the gingival
• Parafunctional habits, e.g. bruxism margin than the apical area.
• Holding objects like pencil, pipe, etc. in between Pulp vitality tests remain normal until the cracks
teeth/opening bottle with teeth involve pulp. Tooth is normally not tender to percussion
• Chewing hard substances, e.g. sugarcane, nuts, bone, on an axial direction. Patient is asked to bite on an
etc. object, such as, applicator stick, Burlew rubber disk,
• Wedging effect of spreader/plugger during obtura- folded rubber dam and wooden stick, etc. This results
tion in separation of cracked fragments which elicits pain.
• Decreased remaining dentin inside the root The bite tests can confirm the diagnosis.
(extensive postspace preparation) Since, the crack usually runs mesiodistally, radio-
• Stresses created due to placement of inlay, pins and graphs do not reveal a fracture. The presence of a lateral
posts, etc. diffuse widening of the periodontal ligament space is
the characteristic radiographic appearance.
• Failure to place proper post endodontic restorations
The pain due to cracked tooth syndrome is to be
• Long span bridges exerting excessive torque on the
differentially diagnosed with pain due to periodontal
abutment teeth.
causes, galvanic pain, orofacial and psychiatric disorders,
Incidence etc.
Men and women are equally affected. Mandibular Treatment
molars, especially second molars are the most Site, extent and direction of fracture line are the three
frequently affected tooth; may be restored or factors, which dictates whether the tooth can be restored
unrestored. In a rough estimate, 3% molars and 1% or not.
premolars encounter fracture in males.
The direction of the fracture can be:
Signs and symptoms • Horizontal, diagonal, vertical
Patient usually complains of momentary discomfort • Mesiodistal or buccolingual.
The fracture may extend:
with cold stimulus or biting from that tooth. The pain
is severe on release of biting force (Table 23.2). The
reason may be that the pressure leads to separation
• Only in enamel
• Both enamel and dentin
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 414 Essentials of Endodontics

• In enamel, dentin and pulp treatment varies from re-contouring the fracture
Further it may extend superficial to the alveolar crest edges to restoring with composites. Usually such
or below the alveolar crest. injury pose no threat to the pulp; however, should
The site of the fracture can be: be evaluated periodically.
• Cervical third The fracture of dentin along with enamel exposes
• Apical third a large number of dentinal tubules to the oral
• Peripherally located environment, which may cause chemical and
• Centrally located. bacterial insult of the pulp. Depending upon the
Immediate treatment of crack tooth involves severity of irritants and host response, the outcome
stabilization with orthodontic bands, followed by may be repair in the form of reparative dentin or
occlusal relief by selective grinding. lead to pulp inflammation. Patient may complain of
The crack line superficial to alveolar crest have better thermal sensitivity or pain on mastication.
prognosis than the ones below the alveolar crest. In case where the fractured segment (may be
Diagonal crack, if peripherally located separating a enamel only or enamel and dentin) is not lost, then
small fragment of tooth, the loose fragment can be reattachment of the fragment can be tried. The
extracted and the rest can be restored. Cracks extending primary aim is to protect the pulp from insult by
subgingivally often require a gingivectomy to expose sealing the open dentinal tubules with appropriate
the margin. In case the crack is vertical and extends material (bonding agents, flowable composites, etc.).
below the alveolar crest involving pulp, the tooth may The missing tooth structure should be restored.
be extracted. Full coverage restoration is preferred. • Complicated crown fracture: The fractures of enamel
Subsequently, if symptoms of irreversible pulpitis are and dentin involving pulp are referred to as
evident treatment should be carried out accordingly. complicated crown fracture. Patient may complain
of sensitivity to hot and cold or/and pain on
f. Tooth Fracture mastication. A small bleeding point or pinkish pulp
Tooth fractures in the anterior region are usually caused can usually be seen.
by direct trauma, while in posterior region, the causes Factors influencing the treatment options are, maturity
can be other than trauma. of root apex, amount of tooth structure lost and
The fractures can be classified as follows: associated injuries. If the root formation is incomplete,
i. Crown fracture pulpotomy is preferred to preserve the pulp for a longer
• Enamel infraction period facilitating normal root development. Mineral
trioxide aggregate (MTA) and calcium hydroxide are
• Uncomplicated crown fracture
the materials of choice for pulpotomy.
• Complicated crown fracture
In tooth with mature root apex, root canal treatment
ii. Crown and root fracture
followed by postendodontic restoration should be
iii. Root fracture
carried out. Depending upon the associated injuries,
• Transverse/horizontal root fracture the tooth may need repositioning and splinting.
• Vertical root fracture. Depending upon the amount of tooth structure loss,
i. Crown fracture the restoration can be planned.
• Enamel infraction: It is manifested as incomplete ii. Crown and root fracture
fracture of the enamel. The cracks can be easily seen The fracture involves both crown and root. Mostly, the
in transillumination or by the use of dye. These teeth fracture line lies superior to the marginal gingiva on
do not need any treatment but should be closely the facial aspect of the crown and runs in an oblique
followed-up for further progress of the crack. Sealing direction below the marginal gingiva on the lingual
the infarction line with unfilled resin may prevent surface. The fractured fragment may or may not remain
further damage. attached to the gingiva. Involvement of the pulp may
• Uncomplicated crown fracture: The fracture of enamel complicate the treatment. When pulp is not involved
or enamel and dentin both without exposing the pulp and the fracture fragment is in one piece, reattachment
is referred to as uncomplicated crown fracture. Most can be tried. In case of multiple fractured fragments
commonly the mesial or distal incisal edges in without pulp exposure, the fractured fragments are
anterior teeth are fractured. When only enamel is removed protecting the underlying pulp. If the fracture

23 fractured, the condition is asymptomatic; but

depending upon the texture of tooth structure lost,
it may cause injury to lips or/and tongue. The
leads to pulp exposure, root canal treatment (ortho-
dontic extrusion, if need be) followed by restoration is
the treatment of choice.

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 Endodontic Emergencies 415

iii. Root fracture open, apexification with calcium hydroxide/MTA is

Q Transverse/horizontal root fracture: The transverse/ tried. If the pulp is nonvital and the coronal fragment
horizontal root fractures involve cementum, pulp, is mobile, root canal treatment can be performed once
dentin and periodontal ligament. Complete fracture the fragment is splinted in position (Table 23.3). In
line may not be visible in single routine radiographs. undisplaced fragments with nonvital pulp, root canal
More than one radiograph with varying angulations treatment of both the fragments can be carried out,
are recommended. followed by placement of rigid post to stabilize both
Clinically, the tooth is slightly extruded with a segments. Unmanaged apical segment should be
lingually displaced crown. The coronal segment is removed by surgical intervention.
laterally luxated. Mobility of the coronal segment If removal of coronal segments is necessary, the
depends upon the level of fracture line and the extent length of remaining root is evaluated. In case of suffi-
of associated injuries to supporting tissues. In cient length, orthodontic extrusion or surgical crown
undisturbed fractures the apical segment usually lengthening can be carried out, subsequently restoring
remains vital, whereas vitality of coronal segment with post and core.
depends upon the extent of injury. Pulp sensitivity test If the length is not sufficient, then extraction becomes
may not be helpful. necessary. Maintenance of good oral hygiene is
The healing of transverse/horizontal root fracture absolutely critical, especially when the fracture line is
has been categorized into four types: close to the alveolar bone margin. Gingival inflamma-
a. Union of the apical and coronal segment by hard tion may result communicating the root fracture line
tissue (the fragments remain undisplaced and non- with the oral environment.
mobile. Radiographically, the fracture line is seen as
a thin radiolucent line). Treatment protocol for transverse/horizontal root
Table 23.3
b. Union of the apical and coronal segment by fibrous fractures
tissue (the fragments appear separated by a definite Level of Mobility Vitality Splinting Endodontic
radiolucent line). fracture treatment
c. Union of the apical and coronal segment by bony in Apical 3rd – + No No
growth across the fracture line (the fragments are Apical 3rd – – No Yes
separated by a distinct bony ridge. This type usually Middle 3rd – + No No
occurs during growth spurts of the child).
Middle 3rd + + Yes No
d. Union of the apical and coronal segment by granula-
Middle 3rd + – Yes Yes
tion tissue (the fragments usually do not join; fracture
line communicates with the oral cavity. Granulation Coronal 3rd – + No No
tissues in-between the fractured segments initiate Coronal 3rd + + Yes No
healing. Response to pulp testing is negative). Coronal 3rd + – Yes Yes

Treatment
Q Vertical root fracture: This type of fracture extends
Treatment depends upon many factors, such as: vertically down the long-axis of the root and usually
• Level of fracture line involves pulp and the periodontium. The etiological
• Vitality of pulp factors can be same as for cracked tooth syndrome.
• Mobility of fragment The operator related reasons are more prevalent for
• Degree of displacement of fragments. such a fracture. Most common orientation of vertical
Fracture line can be in apical, middle or coronal third root fracture is mesiodistal involving both the
of root. Mostly, the apical and middle third fracture do marginal ridges.
not lead to mobility of fragments; no need to stabilize. Clinical features and diagnostic methods are same
Fracture line in coronal third results in mobility of as for cracked tooth syndrome. CBCT images are
coronal fragment, which requires splinting for 2–4 considered better than conventional radiography in
weeks. In majority of cases the apical fragment retains evaluating the vertical fractures.
its vitality, thus needs no treatment. Do not attempt
any endodontic treatment and closely follow-up the Treatment
case for any adverse reaction. If sign and symptoms
indicate pulpal involvement, endodontic treatment is
initiated. If the apical end of the coronal segment is wide
The vertical root fracture can be treated by extracting
the fractured tooth atraumatically, bonding the
fragments (adhesive resin/4-meta resin used as
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 416 Essentials of Endodontics

Table 23.4 Treatment protocol for vertical root fracture direction and reposition the tooth into its natural
Symptoms Segment mobility Treatment position. Finally, the tooth is splinted. Follow-up is
mandatory to evaluate any adverse pulpal changes.
Absent Absent Bonded intracoronal restora-
tion and full coverage crown v. Intrusive luxation: Intrusive luxation is a type of
injury that involves displacement of the tooth into
Present Absent Bonded intracoronal restora-
tion and full coverage crown
the alveolar socket. This type of injury usually
involves the maxillary anterior teeth and is more
Present Present Extraction
common in the primary than permanent dentition.
Intrusion wound involves disruption of the marginal
bonding agent) and then replanting the tooth with a
gingival seal, alveolar bone, periodontal ligament
180° rotation. The rotation of the tooth facilitates
fibers, cementum and the neurovascular supply of
connection of the healthy periodontal membrane to the
the pulp. The injury may lead to complications such
fractured root. The application of bioresorbable
as, ankylosis, pulp necrosis, pulp obliteration,
membrane on root surfaces reinforces the periodontal
external root resorption and loss of marginal bone
healing. It allows regeneration of periodontal ligament
support. In teeth with incomplete root formation,
cells, providing space for the in-growth of periodontal
slight movement of the apex may not lead to
ligament tissues. The treatment protocol for vertical
disruption of the blood vessels.
root fracture is summarized in Table 23.4 (for details
The treatment modalities include passive reposition-
refer to Chapter 26).
ing, active repositioning with orthodontic forces, and
g. Luxation Injuries immediate surgical repositioning. Pulpal necrosis is a
Luxation injuries are classified into five distinct types: common sequel necessitating root canal treatment.
i. Concussion: Concussion is the injury to the h. Avulsion
supporting structure of the tooth. There is no
Avulsion implies total extrusion of tooth from the
loosening and the tooth is reactive to percussion.
socket. Tooth avulsion is a physical and mental trauma
Splinting is not needed. Occlusion should be
for the patient.
relieved. The tooth should be evaluated periodically
Incidence of tooth avulsion ranges from 1–16% of
for any adverse pulp reaction.
all traumatic injuries to the permanent teeth. Maxillary
ii. Subluxation: Loosening of the tooth with no clinical teeth, particularly the central incisors are the most prone
and radiological evidence of displacement. Usually teeth for avulsion. Males are three times more prone
splinting is not required, however if several teeth than females.
are subluxated, a splint may be effective. Splint The fate of avulsed tooth depends upon the biological
should be removed in 7–10 days and follow- up is reaction in periodontal ligament and pulp. Avulsion
mandatory because of the greater chances of pulpal leads to the damage of the following tissues:
necrosis (6–47%) in such cases.
• Pulpal tissue due to detachment of blood and nerve
iii. Extrusive luxation: The teeth are partially displaced supply
from its alveolar socket. Radiographs at multiple • Periodontal ligament due to separation of tooth from
angles may better depict severity of dislocation. The socket
tooth is forcibly repositioned in the socket under • Cemental tissue due to physical trauma
local anesthesia. Formation of clot apical to the
• Fracture of alveolar socket wall
displaced tooth may pose difficulty in reposition-
• Injuries to the lips and gingiva.
ing. A splint should be placed for one to two weeks.
Follow-up is mandatory to evaluate any adverse Management
pulpal sequelae. The time factor plays a major role in the prognosis of
iv. Lateral luxation: The tooth is eccentrically treatment, therefore, emergency attention is important.
displaced, may be due to fracture in the alveolar The following factors influence the treatment plan
socket. Since, the laterally luxated tooth is part of and the prognosis:
the fractured alveolar socket, repositioning may be • Viability of periodontal ligament on the root surface
more difficult as compared to extrusive luxation • Stage of root formation at the time of avulsion
injuries. Anesthesia should be given before • Duration for which the avulsed tooth remained

23 repositioning. The thumb and index finger can be

used to force the displaced tooth within the alveolar
bone and then apply axial pressure in an apical
outside the oral cavity
• Handling of avulsed tooth during procedure (root
canal treatment)

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 Endodontic Emergencies 417

• Transportation media During clinical examination, check for intactness of

• Care of alveolar socket socket and the surrounding bone. Rinse the socket
• Care of associated dentoalveolar injury, if any gently with normal saline to wash out the debris and
clot. Do not curette the socket. If the alveolar bone is
• Expiration of dental splint.
collapsed and prevents replantation, carefully insert a
Replantation is the accepted treatment modality. blunt instrument into the socket to reposition the bone
Replantation is defined as ‘replacement of tooth in its to its original position. After replantation, manually
socket that has been removed from the alveolar socket either compress facial and lingual bony plates. If the tooth
intentionally or by trauma.’ Periodontal ligament, pulp was replanted at accident site, its position in the socket
and alveolar socket are all important tissues to be should be assessed by clinical and radiographic
handled with care. examination. If acceptable, then splinting, soft tissue
a. Management outside dental office: The extraoral time management and adjunctive therapy are carried out. If
of the avulsed tooth should be kept as minimum as unacceptable, then gently remove the tooth and replace
possible. The dehydration of periodontal ligament it in correct position.
fibers should be avoided to retain normal metabolism It is established that the success rate is higher when
of the periodontal ligament cells. Every effort should be the avulsed tooth is immediately replanted at the
made to replant the tooth within the first 15–20 minutes. accident site. The length of extraoral time and the stage
The tooth is washed gently in the running water or of root formation determines the prognosis.
saline and place it in the socket by the patient. Firm Preparation of root
pressure should be applied to keep the tooth in socket i. If the root apex is closed and extraoral time is less
till the patient reaches the dental clinic. If placement of than twenty minutes, revascularization might not
tooth is not possible, the tooth should be transported be possible; however, as extraoral time is less,
to the dental clinic in suitable transportation medium periodontal healing is expected to be excellent. The
(also refer to Chapter 26) such as: tooth and socket are gently rinsed with normal
• Milk: Milk is usually easily available at or near an saline and the tooth is placed in the socket without
accident site. It has a pH and osmolality compatible causing further trauma.
with vital cells and it is relatively free of bacteria. ii. If root apex is open and the extraoral time is less than
Patient’s own saliva is preferred, as milk may contain twenty minutes, the chances of revascularization are
many antigens that could act immunologically bright. Soak the tooth in 1.0 mg doxycycline and
negative on the re-attachment process. 20 ml of saline for five minutes before replantation.
• Vestibule of the mouth: Vestibule of the mouth keeps The doxycycline inhibits bacteria in the pulpal lumen
the tooth moist but not ideal because of its pH, which may otherwise prevent revascularization.
incompatible osmolality and presence of bacteria. iii. If extraoral time varies between 20–60 minutes
Sometimes patient’s condition due to accident does (apex may be closed or open), the tooth should not
not allow placement of tooth in vestibule. be replanted immediately, but placed in a solution
• Saline/water: Saline and water is the least desirable of HBSS for 30 minutes before replantation. The
storage medium, because the hypotonic environment necrotic cells and debris including bacteria float-
causes rapid cell lysis. off of the root during the soaking period, leaving
• Cell culture media: The cell culture media enhance the less stimulus for inflammation.
possibility of maintaining the viability of the perio- iv. If extraoral time is more than 60 minutes (apex may
dontal ligament cell for an extended time after be closed or open), the tooth loses almost all perio-
avulsion, e.g. Save-a-tooth that contain Hanks dontal ligament cells thus soaking is ineffective.
Balanced Salt Solution (HBSS). Now, all efforts will be focused to slow the
An enamel matrix derivative, Emdogain, has been inevitable resorption. The tooth should be soaked
found to improve the periodontal regeneration after in citric acid for five minutes, in 2.0 mg stannous
replantation. fluoride for five minutes and then doxycycline for
another five minutes after which it can be replanted.
b. Management in dental office: After medical and Alendronate is equally effective as fluoride in
dental history, carry out clinical examination of hard slowing resorption; however, this material is costly.
and soft tissue. Alveolar fracture is to be evaluated
carefully. In case of serious injury, the patient is referred
to physician/orthopedician as required.
Emdogain is showing promising results in reducing
resorption when put in the socket. The endodontic
treatment can be completed prior to replantation.
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 418 Essentials of Endodontics

Splinting and toxins in the root canal; may cause pressure and
The requisite features of a splint are: subsequently pain to the patient. It is one of the
• Should be esthetically and hygienically acceptable principle factors contributing to the endodontic failures.
• Should not facilitate caries development Thorough débridement is mandatory for preventing
• Can be easily constructed in the dental clinic such a problem.
• Should not hinder vitality tests and the endodontic b. Apical Periodontitis
treatment.
i. Due to over instrumentation: Instrumentation
Semi-rigid splint is preferred, which allows slight
beyond the apical constriction causes trauma to the
vertical movement of the tooth during healing. The
apical periodontal ligament. Over instrumentation
masticatory stimulus help reorienting necrotic
may cause extrusion of significant amount of
periodontal ligament fibers with blood vessels and
infected debris into the apical area. It also promotes
fibroblasts, minimizing the risk of ankylosis. A thin
the enlargement of apical foramen which may
orthodontic wire (0.3 mm), fiber glass nylon splint and
permit an increased flux of exudate and blood into
titanium trauma splint are routinely used to achieve
the root canal, which further enhances the nutrient
functional immobilization. Prolonged and rigid
supply to the bacteria in the canal. Gross over-
immobilization increases the risks of external
instrumentation can cause acute apical periodontitis
replacement root resorption. Occlusion should be
leading to pain. It can be prevented by maintaining
checked as hyperocclusion impairs healing. For gaining
the working length and selection of an instrumen-
proper periodontal support, splinting for one weak is
tation technique that extrudes less amount of debris
sufficient; whereas, splinting for 4–8 weeks is
apically.
mandatory for alveolar fractures.
ii. Due to chemical insult: Most irrigants and
Patient is advised to consume soft diet, use mouth
medications are cytotoxic, so their use should be
rinses and maintain good oral hygiene. Biting on
restricted to the root canal. If such chemicals are
splinted teeth is to be avoided. Systemic antibiotics/
extruded beyond the periapex, they may lead to
analgesics contribute to replantation success.
inflammation and subsequently pain. Irrigants like
The replanted teeth with open apex (open apices
sodium hypochlorite and hydrogen peroxide when
have the potential to revascularize and continue root
accidentally injected beyond apex into the peri-
development) should be followed closely every two
radicular tissues may cause immediate pain and in
weeks for evidence of revascularization. If any sign of
a few hours, swelling, ecchymosis, neurological
pathology is noted, root canal treatment is initiated.
deficit and even necrotic ulcer. After few days,
Vitality tests are usually not confirmative as open apex
secondary infection and persistent pain may follow.
give false results; however, cold test with carbon
dioxide snow (–78°C) or difluorodichloromethane Management
(–50°C) can be effective. Laser Doppler flowmetry may The best management is prevention. Adequate control
also be useful. of the working length coupled with use of side-vent
Calcium hydroxide is preferred as dressing, as it needles can prevent such accidents. However, in case
favorably influences the local environment at the of such an accident, carry-out immediate aspiration
resorption site and promote healing. The alkaline pH along with irrigation with saline. Patient is prescribed
of calcium hydroxide may slow the action of the cold packs, analgesics and anti-inflammatory drugs. In
resorptive cells and promote hard tissue formation. severe cases, hospitalization is recommended for care
Other medicaments used to prevent resorption are of surgical wound.
antibiotic—corticosteroid paste (Ledermix) and
hormone (Calcitonin). Periodic follow-up is necessary c. Phoenix Abscess (Mid-Treatment Flare-Up)
to evaluate any adverse changes. The phoenix abscess is the synonym of mid-treatment
flare-up. The flare-up is defined as ‘an acute exacerbation
2. Mid-treatment Emergencies of periradicular pathosis during root canal treatment.’ It is
Mid-term emergencies can be because of the following very annoying and upsetting both for the patient and
factors: the operator when the tooth under endodontic
treatment suddenly becomes symptomatic (pain,
a. Incomplete Pulp Tissue Removal
23 Incomplete removal of inflamed pulp tissue lead to
survival of residual microorganisms, their by-products
swelling or both). The swelling in such cases is so
profound that the patient avoids going to the same
clinic.

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 Endodontic Emergencies 419

The incidence of mid-treatment flare-ups vary reported. The problem is so severe, which warrants
between 1.0 and 25%. The root canal therapy in vital emergency attention.
teeth exhibits minimum flare-ups. The problem mainly
Preventive measures
lies with chronic cases lying dormant for the last couple
of years. • Before initiating endodontic procedure, the patient
should be mentally prepared and confident of the
Patients with preoperative pain had a flare-up rate
procedure. Fear and anxiety may exacerbate the
of 20%; whereas, patient with localized or defuse
patient perception, subsequently reducing the pain
swelling show 15% incidence of flare-up.
tolerance.
The term Phoenix (rebirth) abscess relates to the
• Avoid half-hearted root canal therapy. All canals
sudden exacerbation of a previously symptom less
should preferably be prepared in one sitting. Missing
periradicular lesion. The reasons for this phenomenon
canals should also be taken care of.
are not fully understood; however, it is hypothesized
• Intracanal medicament should be used judiciously;
to be due to the alteration of the environment of bacterial
too caustic materials or even excess amount of
flora in the root canal space during instrumentation. A
routinely used ones may leach in periapical area,
few authors are of the view that facultative anaerobes
resulting into painful reaction.
multiply slowly in low oxygen environment of the
periapical tissues. When root canal is opened, suddenly • Forced irrigation causes water-canon effect and
it receives oxygen, and in improved condition the trauma to periapical tissues resulting into violent
bacteria fulminate violently and produce an acute tissue reaction; thus proper irrigation techniques
reaction. Another opinion is that after initial canal should be followed.
instrumentation some strains are severely reduced, • Debris extrusion is a problem with almost all the
whereas other may be relatively unaffected. Since, there techniques of instrumentation. The technique which
are fewer organisms with which to compete; a virulent allows minimum debris extrusion should be selected
strain may rapidly multiply. followed by copious irrigation.
• Over instrumentation should be avoided. Occlusion
Etiology should be relieved if apex is severely violated by over
The probable causative factors are: instrumentation.
i. Factors related to patient: • In retreatment cases, the patient should be informed
• Patient with preoperative pain or swelling. about the chances of occurrence of flare-up.
• Patient with dental phobias (prone because of • Proper coronal seal should be maintained to avoid
their low psychophysiologic tolerance). recontamination of root canal system.
ii. Factors related to periapical pathosis: • Root canal should not be left open for drainage as
• Tooth with chronic necrotic pulp that further contaminates the root canal.
• Retreatment cases • Calcium hydroxide is preferred in-between the
• Teeth with chronic periapical radiolucency. appointments, as is effective during long inter-
appointment delays.
iii. Factors related to treatment procedure:
Various hypotheses and preventive measures of mid
• Incomplete pulp tissue removal or undetected
treatment flare-up is summarized in Table 23.5.
canals
• Over instrumentation; trauma to the periapical Treatment
tissues Reassurance is the most important aspect of treatment.
• Apical extrusion of debris during canal prepara- Intravenous analgesic can be given. Triazolam (0.25 mg)
tion given sublingually or orally has been found safe and
• Extrusion of sealer/obturating material into the effective. Antiallergic drugs should be prescribed since
periapical area the allergy may be a causative factor. The root canal is
• Over medication of root canals opened. Sterilized paper point is inserted to evaluate
• Improper sealing of access cavity any seepage. Incomplete canal preparation should be
completed on the same sitting.
• Traumatic occlusion.
A corticosteroid-antibiotic intracanal medication is
Signs and symptoms used to relieve the symptoms. The paste can be inserted
After an endodontic procedure or during inter appoint-
ment period, the patient had significant swelling, pain
or both. Regional temporary paresthesia has also been
with the help of paper point. Corticosteroids act as a
anti-inflammatory agents, while the antibiotic prevents
any possible over growth of microorganisms.
23

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 420 Essentials of Endodontics

Table 23.5 Mid treatment Flare-up: Various hypotheses and preventive measures
Hypotheses Reasons Preventive measures
Extrusion of infected debris in the Endodontic therapy may introduce • Prefer crown down instrumentation
periapical area medicaments, irrigating solutions or technique
tissue proteins into the periapical lesion • Instruments should be used with rotation
leading to violent reaction rather than pull and push action
• Copious irrigation with mild irrigant
Changes in root canal/periapical Endodontic therapy causes changes in the • Completion of root canal preparation in
environment root canal environment that may favor the single visit
overgrowth of certain microorganisms. If • Placement of a mild antimicrobial intra-
these bacteria reach sufficient number, they canal medication with gentle pressure
can damage the periradicular tissues
Secondary infections Microorganism that are not present in the • Prepare root canal under strict aseptic
primary infection may penetrate the root measures
canal system during or after the treatment • Achieve coronal sealing
• Do not leave the tooth open for drainage
• Placement of an antimicrobial intra-
canal medication
Increase of the oxidation-reduction Entry of oxygen into the root canal during • Completion of root canal preparation in
potential treatment may favor the overgrowth of single visit
facultative bacteria • Copious irrigation prior to intracanal
medication

Access opening is closed with fast setting temporary the only solution. In multirooted teeth, however,
cement and the occlusion is relieved. hemisection can be planned.

3. Post-treatment Emergencies Use of Antibiotics

a. Over instrumentation: Over instrumentation during It has been established that most of the endodontic
root canal preparation, especially in case of single visit emergencies do not require antibiotic coverage.
root canal treatment, lead to pain after obturation. The Unnecessary use of antibiotics may lead to bacterial
filling should be removed and the tooth is kept at rest; resistance. These are only indicated for febrile patients,
subsequently, re-filling after the symptomatic subside. lymphadenopathy, malaise, cellulitis, unexplained
trismus, osteomyelitis and progressive and/or
b. Over obturation/sealer extrusion: The over obturated
persistent swelling. Antibiotics are also indicated as
teeth may create emergency; however, the mild
prophylactic coverage in medically compromised
symptom of pain and tenderness resolve within a day
patient. Pain is not an indication for continuity of
or so.
antibiotics. High dose regimen for a short period is
Over obturation will lead to higher incidence of preferred to a low dose for a longer time. Most of the
discomfort, which may be related to the mechanical and antibiotics may not demonstrate any significant clinical
chemical trauma exerted by the obturating material effects within the first 24 hours, which is not an
and/or sealer to the periradicular tissues. The pressure indication of a failure of antibiotics or a need to change
created by infected extrusion of sealer may also lead to the antibiotic. Swelling may take a few days to one week
severe pain. for resolving. Reduction of pain is a good indication of
c. High restoration: The high points in coronal restora- effectiveness of treatment.
tion (may be interim or permanent) causes discomfort
due to acute periodontitis. Relieving the occlusion BIBLIOGRAPHY
immediately restore the inflammation and the pain. 1. Andreasen FM and Andreasen JO. Diagnosis of luxation
injuries. The importance of standardized clinical,
d. Root fracture: The fracture occurs mainly due to
radiographic and photographic techniques in clinical
unreasonable condensation of the obturating material. investigations. Endod. Dent. Traumato.: 1985; 1:160–169.
During postpreparation, similar fracture can occur if 2. Brain M, Hury and John F. Trephination for acute pain

23 the proper direction is not followed.

The prognosis of root fracture, since mostly, the
fractures are vertical, is very poor. Extraction may be
management. J. Endod.: 2003; 29:144–146.
3. Caglar E, Tanboga I and Susal S. Treatment of avulsed teeth
with Emdogain–a case report. Dent. Traumatol: 2005; 21:51–53.

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4. Christopher D, Lynch RJ and Mc Connell J. The crack tooth 13. McDougal RA, Olutayo, Delano E and Dan C. Success of an
syndrome. J. Can. Dent. Assoc.: 2002; 68:470–475. alternative for interim management of irreversible pulpitis.
5. Cunha RF, Delbem ACB, Vietra AEN and Pugliesi DNC. JADA.: 2004; 135:1707–1712.
Treatment of a severe dental lateral luxation association with 14. Priyanka SR and Veronica. Flare-ups in endodontics – a
extrusion in an 8-months old baby : A conservative approach. review. IOSR J. Dent. Med. Sci.: 2013; 9:26–31.
Dent. Traumatol.: 2005; 21:57–59. 15. Samuel S and Irving JF. Flare-ups in endodontics: I. Etiological
6. Ernest H, Harold H. and Robert M. Flare ups in endodontics factors. J. Endod.: 2004; 30:476–481.
and their relationship to various medicaments. Aust. Endod. 16. Sathorn C, Parashos P and Messer H. The prevalence of post-
J.: 2007; 33:119–130. operative pain and flare-up in single and multiple-visit
endodontic treatment: A systematic review. Int. Endod. J.:
7. Henry M, Reader A and Beck M. Effect of penicillin on post
2008; 41:91–99.
operative endodontic pain and swelling in symptomatic
necrotic teeth. J. Endod.: 2001; 27:117–123. 17. Sathorn C, Parashos P and Messerj HH. Effectiveness of single
versus multiple visit endodontic treatment of tooth with apical
8. Houck V, Reader A, Back M, Nis R. and Weaver J. Effect of
periodontitis: A systematic review and meta analysis. Inter
trephination in post operative pain and swelling in Endod. J.: 2005; 38:347–355.
symptomatic necrotic teeth. Oral Surg., Oral Med., Oral Path.:
18. Segura-Egea JJ, Cisnero-Cabello R, Llamas-Carreras JM and
2000; 90:507–513.
Velasco-Ortega E. Pain associated with root canal treatment.
9. Iqbal M, Kurtz E and Kohli M. Incidence and factors related Int. Endod. J.:2009; 42:614–620.
to flare-ups in a graduate endodontic programme. Int. Endod.
19. Strobl H, Haas M, Norea B, Gerhard S and Emshoff R.
J.: 2009; 42:99–104. Evaluation of pulpal blood flow after tooth splinting of luxated
10. Keenan V, James GF, Allan F, Zbingniew NT and Jonothan permanent maxillary incisor. Dent. Traumatol.: 2004; 20:36–41.
A. A Cochrane systematic review finds no evidence to support 20. Trope M. Clinical management of the avulsed tooth. Dent.
the use of antibiotic for pain relief in irreversible pulpitis. J. Clin. North Am.: 1995; 39:93–112.
Endod.: 2006; 32:87–92.
21. Turpo JC and Gobetti JP. The crack tooth syndrome: an elusive
11. Levein L, Bryson EC, Caplan D and Trope M. Effect of topical diagnosis. J. Am. Dent. Assoc.: 1996; 27:1502–1507.
alendronate on root resorption of dried replanted dog teeth. 22. Villanueva LE. Fustobacterium necleatum in endodontic flare-
Dent. Traumatol.: 2001; 17:120–126. ups. Oral Surg., Oral Med., Oral Pathol., Oral Radiol. Endod.:
12. Liesigner A, Marshall JF and Marshal GJ. Effect of variable 2002; 93:179–183.
doses of dexamethasone on post operative endodontic pain. 23. Walker RT. Emergency treatment—a review. Int. Endod. J.:
J. Endod.:1993; 19:35–39. 2984; 17:29–35.

23

t.me/Dr_Mouayyad_AlbtousH
 Chapter
24
Bleaching of
Discolored Teeth

Esthetics is the science of beauty. Esthetic dentistry not TOOTH DISCOLORATION AND STAINING
only relates to disfigured teeth but also involves the The tooth discoloration and staining are multifactorial.
needs of normal appearing people who wish to look A thorough knowledge of the etiology of tooth staining
younger, healthier and confident. The perception and is essential in order to make a correct diagnosis. The
description of color in a given object, coupled with the factors and extent of discoloration influence the
need and desire of an individual forms the basis of treatment options and also determine the prognosis.
esthetics. One of the most frequent reasons warranting The vitality of the tooth also affects the treatment
esthetic care is discoloration of anterior teeth. The protocol and timings.
improved technical ability of the dental surgeons along
with better gadgets and also the increasing awareness Etiology
of the public has paved the way for improving the The etiology of tooth discoloration is broadly divided
esthetics of the discolored teeth and the surrounding into three categories, viz. intrinsic, extrinsic and
tissues. The lightening of stained teeth without internalized stains.
disturbing the biological tissues and the periodontal
environment is the main goal of the practicing esthetic A. Intrinsic Discoloration
dental surgeon. The factors causing intrinsic discoloration are classified
The lightening of the color of a tooth through as local and systemic factors. A few authors have
application of chemical agent(s) to oxidize the organic categorized the causes of intrinsic discoloration as pre-
pigmentation in the tooth, is referred to as ‘Bleaching’. eruptive and posteruptive causes.
American Dental Association defined bleaching as, ‘the a. Local factors
treatment, involving an oxidative chemical that alters the i. Trauma: Trauma leads to pulpal hemorrhage,
light absorbing and/or light reflecting nature of the material causing grayish discoloration of the teeth. The
structure, thereby increasing its value (whiteness)’. obliteration of the pulp canal may add to dark
The term ‘bleaching’ and ‘tooth whitening’ are not yellow discoloration of the teeth.
exactly synonymous. Whitening restores teeth to their ii. Pulpal hemorrhagic products: Pulp necrosis leads to
natural tooth color (removal of external stains on the the production of hemorrhagic products, which
tooth surface) and bleaching makes the teeth lighter enter dentinal tubules and cause discoloration.
than their natural color (modify colored substances iii. Aging: Aging changes enamel and dentin structure,
within the tooth). which eventually lead to discoloration.
‘Bleaching’ or ‘tooth whitening’ dates back to 18th iv. Root resorption: Root resorption, especially at a later
century when the chloride of lime was used as a stage, discolor the tooth.
bleaching agent. In early nineteenth century, hydrogen b. Systemic factors
peroxide, alone and in combination with other i. Fluorosis: It has been established that high
materials, have been used as a bleaching agent. Over concentration of fluorides (more than 4.0 ppm)
the years, various investigators have tried different causes moderate to severe discoloration; more
materials and technique to aid in bleaching. Bleaching prevalent in incisors followed by premolars and
with lasers is also being familiarized. molars. Fluorosis is categorized as mild, moderate

422

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 Bleaching of Discolored Teeth 423

and severe. Mild fluorosis exhibits brown pigmen- Posteruptive

tation on a smooth surface, moderate shows flecks • Aging
on the enamel surface along with staining, and • Root resorption
severe form shows pigmentation with pitted • Pulp necrosis
enamel surfaces. The severe form of fluorosis may • Intrapulpal hemorrhage
not respond to bleaching. • Pulp tissue remnants
ii. Tetracycline staining: Tetracycline is a widely used • Materials (irrigants, sealers, etc.)
antibiotic. Discoloration due to tetracycline
ingestion has been confirmed by various B. Extrinsic Discoloration
investigators. It was also established that the dose Extrinsic discoloration have been classified by various
of tetracycline was more important than the authors depending upon different criteria:
duration. The different varieties of tetracycline a. Classification according to the cause:
produce yellow to yellowish brown stains; • Staining, caused by chromogenic microorganisms
however, doxycycline does not produce any stain. derived from dietary sources; other factors may
iii. Amelogenesis imperfecta: Amelogenesis imperfecta, also be responsible
the abnormal formation of the enamel, is of three • Indirect staining is associated with cationic
types, viz. hypoplastic, hypomineralization and antiseptics and metal salts.
hypomaturation. b. Nathoo’s classification:
• Type 1 (N1): Chromogens bind to tooth surface and
iv. Dentinogenesis imperfecta: Dentinogenesis imperfecta
cause discoloration. The color of the chromogen
is an autosomal dominant developmental distur-
is similar to that of dental stains caused by tea,
bance of the dentin. It leads to brownish violet to
coffee, wine and various chromogenic bacteria.
yellowish brown color of the dentin with a trans-
• Type 2 (N2): Chromogen changes color after
lucent hue.
binding with teeth. The stain darkens with time
v. Dentin dysplasia: Dentin dysplasia is a rare • Type 3 (N3): Prechromogen (colorless material)
disturbance of dentin formation, may lead to slight binds to tooth and undergoes chemical reaction
amber translucency of teeth. to cause the staining.
vi. Congenital hyperbilirubinemia: High level of bilirubin c. Non-metallic stains:
in the blood, may cause yellow green discoloration • Due to tea, coffee, blackcurrant juice, cola drinks
of teeth. etc.
vii. Congenital erythropoietic porphyria: An inborn error • Due to chemicals, like chlorhexidine.
of porphyrin-haem synthesis (inherited as an d. Metallic stains:
autosomal recessive trait); may lead to red brown/ • Black staining seen in people using iron supple-
purplish red discoloration of the teeth. ment and in iron foundry workers
viii. Alkaptonuria: An inherited genetic disorder of • Copper causes green stain after rinsing with
phenylalanine and tyrosine metabolism, may give copper salts
brown discoloration to the teeth. • Potassium permanganate produces violet to black
color
ix. General diseases: Diseases of genetic/idiopathic
• Silver nitrate salt causes gray discoloration
origin, such as epidermolysis bullosa, cleidocranial
• Stannous fluoride causes golden brown discolora-
dysostosis, osteogenesis imperfecta, osteopetrosis,
tion.
Morquio’s disease, etc. Prenatal or congenital
syphilis, trophic disturbances like infantile tetany, C. Internalized Discoloration
rickets, vitamin C deficiency, etc.
Internalized discoloration occurs due to incorporation
of extrinsic stains within the tooth substance following
Causes of intrinsic stains have also been categorized as pre-
some dental pathology. It occurs in enamel defects and
eruptive and posteruptive
in the porous surface of exposed dentin, e.g. in
Pre-eruptive developmental defects like fluorosis, hypoplasia and
• Tetracycline
enamel hypocalcification. These types of defects can also
• Fluorosis
• Trauma
• Genetic (amelogenesis imperfecta, hyperbilirubinemia)
be seen in tooth wear, gingival recession and caries, etc.
The causes of discoloration are summarized in
Flowchart 24.1.
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 424 Essentials of Endodontics

Flowchart 24.1 Causes of discoloration

BLEACHING OF TEETH Disadvantages

Bleaching implies degradation of high molecular • Unknown duration of the treatment
weight, complex organic molecules that reflect a specific • Discomfort of rubber dam application
wavelength of light, responsible for color of the stain. • Temperature rise on the pulp
The degradation leads to lower molecular weight • Post-treatment sensitivity
molecules, that reflect less light, resulting in reduction/ • If etching is performed with bleaching (resulting in
elimination of discoloration. loss of small amount of enamel), polishing is required
Factors limiting the bleaching of teeth after each visit
• Dentin hypersensitivity • Cost factor.
• Suspected or confirmed bulimia The bleaching modalities are divided into vital and
• Generalized dental caries and leaking restorations nonvital tooth bleaching.
• Heavily restored teeth I. Vital tooth bleaching
• Teeth with opaque white spots A. In-office bleaching
• Patient selection—patients with emotional or a. Thermocatalytic bleaching
psychological problems do not make good b. Nonthermocatalytic bleaching
candidates for bleaching c. Power bleaching
• Decreased bonding of adhesive materials to the tooth d. Microabrasion
immediately after bleaching. B. Home bleaching (nightguard vital bleaching).
Indications II. Nonvital tooth bleaching
• Superficial color discrepancies a. Thermocatalytic technique
• Extrinsic/intrinsic stains of moderately dark and b. Walking bleach technique
intense color c. Modified walking bleach technique
• General discoloration of teeth (yellow to brown). d. Combination technique (inside/outside bleaching).
III. Laser assisted bleaching.
Contraindications
IV. Tooth bleaching with nonthermal atmospheric
• Severe discoloration from amalgam corrosion plasma.
• Extensive restorations
V. Over the counter products.
• Inherent sensitivity of the patient to bleaching agents.
Advantages I. VITAL TOOTH BLEACHING
• Treatment is totally under control of the operator
24 • Potential for early results
• Soft tissue can be protected from the process.
Vital bleaching technique requires use of chemical
agents that should not endanger the tooth structure and
the adjoining soft tissues.

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 Bleaching of Discolored Teeth 425

Bleaching Agents ii. Thickening agents: Carbopol (carboxypolymethylene),

The bleaching agents contain active and inactive in a concentration of 0.5 to 1.5%, is commonly used
ingredients. thickening agent. It increases viscosity of the
bleaching agent and also increases active oxygen
The active ingredients include:
releasing time of the bleaching material.
i. Chlorine dioxide: 0.5% chlorine dioxide when applied iii. Surfactants in bleaching agent act as surface wetting
to enamel surface for 20 minutes, effectively bleach agent facilitating diffusion of hydrogen peroxide
the tooth surfaces. However, its use may lead to across the tooth surface.
roughness on enamel surface and decreased luster. iv. Glycerine and propylene glycol added as carrier,
Such teeth are more prone to restaining and usually enhance viscosity and facilitate uniform distribu-
develop sensitivity. tion of bleaching agent.
ii. Hydrogen peroxide: 30–35% hydrogen peroxide is a v. Certain flavoring agents, such as peppermint,
strong oxidizing agent that ionizes to produce wintergreen, spearmint, etc. are added to improve
different type of free radicals, such as hydroxyl ions taste and patient’s acceptance.
(OH–) and perhydroxyl ions (OOH–). vi. Potassium nitrate and fluorides are added to
iii. Carbamide peroxide: Carbamide peroxide is decrease post-treatment sensitivity.
hydrogen peroxide combined with urea. 10–35% vii. Certain remineralizing agents, such as calcium
concentration of carbamide peroxide is being used phosphate-casein phosphopeptide, are added to
for bleaching purpose (10% carbamide peroxide is reduce sensitivity and also to get lustrous shine to
equal to 3.0% hydrogen peroxide and 22% the teeth.
carbamide peroxide is equal to 7.5% hydrogen
Additional materials used during bleaching procedure
peroxide). Higher amount of peroxide is more
effective; however, associated with increased risk a. Orabase paste: Orabase paste is used to protect
of sensitivity. A few pH buffered products are gingiva and oral mucosa during bleaching. It is
available, which reduce likelihood of side effects. composed of gelatin, pectin and sodium carboxymethyl-
cellulose in plastibase (plasticized hydrocarbon gel).
iv. Hydrochloric acid: The hydrochloric acid(18–36%) Orabase paste adheres tenaciously and remains in
causes decalcification of tooth substance along with intimate contact with mucous membranes, protecting
removal of stain. the affected area in the oral cavity against irritation from
v. Titanium dioxide nanoparticle doped with nitrogen to chewing, swallowing, etc. It acts as an invisible
bleaching agent having less concentration of bandage. A thin film of orabase paste is effective.
hydrogen peroxide (3.0–10.0%) is recently tried as
bleaching agent. The combination improves the b. Gingival dam: The gingival dam is the polymerizable
biocompatibility of the solution reducing dental isolation barriers, which is used during bleaching
sensitivity during and after the procedure. Recent process. The barrier material consists of:
studies have confirmed the clinical efficacy of this • Monomers
newer bleaching agent with 3.0–6.0% hydrogen • Curing agents (0.01–2%)
peroxide. • Polymerization strength reducers (1–30%)
• Tissue adherence accentuators (0.01–9%)
vi. Other bleaching agents: The whitening toothpastes
• Reflective materials (1–50%).
and tooth whitening gels mainly contain calprox-
The polymerizable isolation barrier consists of at least
baking soda-sodium bicarbonate (mild abrasive,
one monomer, one curing agent for curing the monomer
dissolves protein pellicle layer and whiten teeth);
and one of three preferred additives, i.e. the organic
Hydrated silica-silicone dioxide (mild abrasive, can
polymerization strength reducer, the tissue adherence
be combined with calcium carbonate to increase
accentuator, and the reflective material. The poly-
effectiveness); sodium tripolyphosphate (detergent,
merizable isolation barrier material is preferably stored
removes stains) and polyvinylpyrrolidone (do not
at or below room temperature. It is stable enough until
allow new stains adhering to tooth).
activated by suitable light radiant energy.
The inactive ingredients include: The barrier material is made in a paste or gel form
i. Preservatives: Sodium benzoate is commonly used that can be expressed from a dental syringe. The barrier
as preservative agent. It prevents bacterial growth
and also accelerates the breakdown of hydrogen
peroxide.
material is available in form of emulsion, dispersion/
suspension solution depending upon selection of a
preferred application.
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t.me/Dr_Mouayyad_AlbtousH
 426 Essentials of Endodontics

c. Diamond polishing paste: The diamond polishing (vital teeth) and the second is inserted through the
paste incorporates 3.0 μ diamond abrasive particles in coronal access opening (nonvital teeth). The
a strand of fiber. These fibers form a three dimensional recommended temperature for nonvital teeth is 60
open weave design. This paste provides finishing and to 70°C and 46 to 60°C for vital teeth.
polishing in one step. After removing the heat source, tooth is allowed to
cool to avoid sudden temperature change that can be
d. First aid kit: It contains antioxidants such as vitamin E
deleterious to the pulp. After five minutes tooth is
in liquid or capsule form and aloe vera gel. A single
washed with warm water for one minute. Bleaching
spill of a droplet of hydrogen peroxide blanches and
appointments are scheduled 2–4 weeks apart. Do not
burns the gingival tissue. Vitamin E oil quickly relieves
exceed 30 minutes of treatment in each appointment.
the symptoms within one minute.
A minimum of three treatments is required; ten are
The techniques involved in vital bleaching are: maximum. The color is checked one week after the third
A. In office bleaching treatment.
a. Thermocatalytic bleaching The source of heat can be:
b. Nonthermocatalytic bleaching • Photoflood lamp
c. Power bleaching • Polymerization light
d. Microabrasion. • Spirit lamp
• Commercial bleaching units
B. Home bleaching (nightguard vital bleaching).
• Light-heat lamp
A. In-Office Bleaching • Lasers.
The commercial preparation systems utilizing
Preparation of the patient for bleaching
different activating light sources are:
• Shade of the patient's existing dentition is recorded • Quartz tungsten halogen (QTH) curing light: The
with a standardized shade guide tab; photograph of standard curing light provides heat to activate the
patient’s teeth is taken for records chemical reaction by stimulating light sensitive
• Thorough prophylaxis is performed chemicals in the bleaching agent. Conventional light
• The patient is draped with a protective cap and is provide 17°C increase in temperature; whereas, with
made to wear protective eyeglasses QTH light the temperature rises to 24.8°C above
• No local anesthesia is administered the baseline. The application time is approximately
• Teeth are isolated with heavy gauge rubber dam 40 seconds. Each application can be within 40–
50 seconds.
• Before rubber dam application, oraseal (a light cured
resin) or orabase paste is applied to protect the labial • Plasma arc: Plasma arc provides slightly higher intensity
and lingual tissue of light/heat than halogen curing temperature. The
four seconds application may lead to 2.2°C rise of intra-
• Vaseline is applied to the patient’s lips before
pulpal temperature. The total increase in temperature
mounting the rubber dam frame
varies from 37 to 39°C. The recommended time of
• Wet gauze is placed over the patient’s lips to prevent application is 30 seconds per tooth.
thermal trauma. • Rembrandt tooth whitening system: This system
includes the use of a plasma arc light, named
a. Thermocatalytic Bleaching
Rembrandt Sapphire. The unit can be fitted with a
The thermocatalytic bleaching involves the use of heat Rembrandt Whitening Crystal enabling the operator
alone or heat and light both. The units used for thermo- to treat both the arches simultaneously. The wave-
catalytic bleaching are: length of light emitted from this source is in the range
i. Heat light unit: The unit provides high intensity light of 400–525 nm (blue green coloration).
and heat, required to activate bleaching agents. A • Whitening accelerator: This system utilizes high
narrow beam of light is concentrated at one specific intensity blue light at a wavelength of 480–520 nm.
site at a distance of approximately 13–15 inches. The light is filtered to remove infrared and ultraviolet
Calibrated rheostat controls the amount of light and light. It is used with special whitening formula; the
heat. half-hour procedure can oxidize 16 or more teeth.

24 ii. Heat unit: The unit with accurate temperature control

provides the requisite heat to activate the bleaching
agent. Two tips are available: one is directly applied
• The Zoom! (Teeth whitening system): This system
utilizes using mercury metal halide light with a
wavelength of 300–450 nm (violet coloration). The

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 Bleaching of Discolored Teeth 427

Zoom! Light unit has an infrared filter, which filters • A small piece of cotton/gauze piece, held in cotton
these radiations, thereby minimizing the amount of pliers is dipped into the dappen dish and the saturated
heat generated at the surface of tooth during the bleaching solution is applied onto the tooth surface.
bleaching treatment. • With a small plastic instrument, the gauze is shaped
to cover the entire tooth surface.
Technique (Fig. 24.1a to c)
• The selected heating unit is positioned.
• Using a dropper, a small amount of bleaching
solution (30–35% H2O2) is placed into a dappen dish. • When the photo lamp is used, the bleaching solution
is applied every 4 to 5 minutes.
• The teeth are properly isolated preferably with
rubber dam. • When the heat unit is used, the bleaching solution is
applied after every heating cycle.
• After removing the gauze/cotton, the teeth and the
entire rubber dam is washed with warm water and
a high volume vacuum aspirator.
• The floss is removed by cutting with scalpel and
removing slowly with cotton pliers.
• The rubber dam is stretched apically and labially to
gain access to the interproximal areas. The clamps
are removed and the rubber dam is gently teased off
from the teeth.
• Wet, warm gauze pieces are used to remove the
excess orabase/oraseal.
• The residues of bleaching agent on teeth are
a neutralized with a mild warm solution of ½ teaspoon
salt, ½ cup warm water and ½ teaspoon sodium
bicarbonate.
• Instruct the patient to avoid coffee, tea and cold
drinks for two weeks.

b. Nonthermocatalytic Bleaching
The nonthermocatalytic technique does not utilize heat
sources.
The bleaching solutions used are:
• Superoxol (5 parts of H2O2 + 1 part of ether) (Fig. 24.2).

24
c

Fig. 24.1 Thermocatalytic bleaching: (a) Preoperative;

(b) During bleaching process; (c) Postoperative Fig. 24.2 Superoxol

t.me/Dr_Mouayyad_AlbtousH
 428 Essentials of Endodontics

• McInnes solution: 5 parts of 36% HCl (increases the

penetration of solution) + 5 parts 30% H2O2 (bleaches
the enamel by process of oxidation) + 1 part of 0.2%
anesthetic ether (removes the surface debris).
• Modified McInnes bleaching solution consisting of
30% hydrogen peroxide and 20% sodium hydroxide
in 1 : 1 ratio along with 0.2% ether has been introduced
to overcome the deleterious effects of hydrochloric acid.
• Self-activating bleaching agent for vital teeth
[(Composition: 35% hydrogen peroxide (0.4 ml),
calcium oxide (0.12 gm) and aerosil (to alter/control
the viscosity – 0.32/0.64 gm)].
Technique
After polishing the tooth surface and rubber dam Fig. 24.3b Rubber dam isolation
application, paste is applied on the teeth and kept there
for five minutes (Fig. 24.3a to f). The paste can be
reapplied, if required, followed by copious irrigation
with warm water.

c. Power Bleaching
Power bleaching utilizes higher concentration of
hydrogen peroxide (35–45%).
The high intensity light used as a heat source in
thermocatalytic bleaching is replaced with plasma arc
lamps, Xe-halogen lights, lasers, etc. Power bleaching
is mainly used on single tooth or even small area on
the tooth surface that needs to be lightened. It is mainly
indicated in deep tetracycline staining and dentin
sclerosis, which take longer time with nightguard vital
bleaching technique.
Advantage
• Produces immediate results. Fig. 24.3c Polishing with slurry of pumice and distilled
water
Disadvantages
• The caustic nature of the 35–45% H 2O 2 makes
isolation difficult; possibility of soft tissue injury

24 Fig. 24.3a Preoperative Fig. 24.3d Applying McInnes solution

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 Bleaching of Discolored Teeth 429

Contraindications
• Deep stains
• Stains of amelogenesis imperfecta, dentinogenesis
imperfecta and tetracycline stains
• Hypoplastic lesion
• Decalcification areas leading to caries.
Technique (Fig. 24.4a to d)
• The selected tooth or teeth are cleaned with
prophylaxis paste using rubber cups at slow speed
• The teeth are isolated using rubber dam
• Petroleum jelly is applied to adjacent soft tissue
Fig. 24.3e Solution being neutralized by sodium • Microabrasive agent is applied to the tooth surface
bicarbonate for 60 seconds, followed by rinsing
• The process is repeated till the requisite result is
achieved
• Topical fluoride can be applied after the treatment
• Patient’s consent is necessary for the final color
achieved; if not satisfied, the process is repeated.
Advantages
• Helps to remove superficial stains and discoloration
• Minimal discomfort to patient
• Treated teeth display a smooth texture and shine
• Easy manipulation.

Fig. 24.3f Postoperative

• Lead to dehydration of teeth; may give false lighter

shade
• Amount of lightening is not under control
• Greater risk of postoperative sensitivity.

d. Microabrasion
Fig. 24.4a Preoperative
Microabrasion procedure involves surface dissolution
of the stains of enamel by acids (preferably 18%
hydrochloric acid) along with the abrasives (preferably
pumice powder). Microabrasion is indicated for
improvement of particular tooth color. This is also used
in cases where routine bleaching is not effective.
Indications
• Stains limited to superficial enamel surface
• Enamel fluorosis (initial stages)
• Discoloration due to enamel hypo- or hyper-
mineralisation
• Small decalcified lesions, may be due to orthodontic
bands. Fig. 24.4b Polishing the tooth surface
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 430 Essentials of Endodontics

a
Fig. 24.4c Cleaned surface

Fig. 24.5a and b Bleaching trays

Carbamide peroxide in different concentration is

Fig. 24.4d Postoperative used as bleaching agent. As the solution is flown onto
the tooth surface, carbamide peroxide being unstable
Disadvantages dissociates into H2O2 and urea, in different concentra-
• Removes enamel layer; may appear yellowish after tions depending upon the concentration of carbamide
treatment peroxide. The H2O2 further dissociates into water and
• Only effective on those stains, which are confined to oxygen. The oxygen radicals cause oxidation of
outer layer of enamel (not effective for deeper stains) pigmentation in the tooth. The urea degrades into
ammonia and carbon dioxide. Carbopol is added to
B. Home Bleaching (Nightguard Vital Bleaching)
carbamide peroxide to prolong the release of oxygen
10% carbamide peroxide, in a custom fitting bleaching and to counter carbon dioxide released by urea;
tray, is delivered to the patients for their use during night subsequently, improving tissue adherence.
time (Fig. 24.5a and b). The patient is instructed to cover
the teeth with the tray along with the medicament. Commercial preparations
Indications • 10% carbamide peroxide with carbopol (proxigel,
• People dissatisfied with the original color of their ultralite, etc.) (Fig. 24.6)
teeth • 10% carbamide peroxide without carbopol (fast
• Brown fluorosis stains oxygen releasing—glyoxide, dentalite, etc.)
• Discolored teeth that have darkened from trauma • 15% carbamide peroxide (Nu smile)
but are still vital • 1.0–10% hydrogen peroxide (peroxyl, brite smile,
• As retreatment of walking bleach after reversal of etc.)
the treatment
Technique
24 • Lightening of discolored teeth prior to placement of
porcelain veneers
• Lighten natural teeth to match ceramic crowns.
There are three basic regimens for the application of
the whitening solutions.

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 Bleaching of Discolored Teeth 431

iii. Preparing tray with reservoir space (a reservoir is

created between teeth and the tray using a viscous
light cure composite gel).
• The viscous composite spacer gel is applied to
the selected teeth on the cast (about 0.5 mm)
• The facial surface of the teeth is painted covering
1.0 mm from the gingival margin
• The spacer gel is not allowed to flow onto the
incisal edge or occlusal surface
• A light curing unit can be used for curing the
spacer
• The oxygen inhibited resin layer is wiped away
from the spacer
• Tray material is selected and nightguard is
Fig. 24.6 Carbamide peroxide bleaching agent (web constructed in a vacuum forming machine
photo) • The space of spacer gel in the bleaching trays
forms the reservoir.
a. Sleeping with the nightguard tray filled with the Advantages of reservoir
bleaching solution (the solution is changed each
• Provides space for the bleaching agent
night).
• Facilitates seating of tray
b. Wearing the loaded nightguard tray during the day
time and changing the solution every 1.5–2 hours. • Minimizes tooth sensitivity by avoiding the
pinching effect of a light tray
c. Polyethylene strips impregnated with 5.25%
hydrogen peroxide are also used without tray. • Allows uniform transfer of bleaching gel.
Disadvantages of reservoir
The nightguard vital bleaching procedures usually • Increased cost of fabrication and time
require three appointments.
• Decreased tray retention
First Appointment • Gel may leak and irritate gingiva
The shape and color of the teeth along with the gingiva • Preparing tray with foam liner.
is evaluated before initiating the bleaching procedure. iv. Preparing tray using foam liner: The tray is also
The stone cast is formed after taking impressions with formed using foam liners, which are placed on
suitable materials. The tray material is selected (usually the selected area of the cast. The trays are then
0.040 inch or 0.035 inch ethyl vinyl acetate is used for fabricated, in routine, in a vacuum forming
fabricating the tray; 0.020 inch polypropylene has also machine.
been used). Advantages of foam liner
The tray material is placed in the retainer frame on • Soft on patient’s gingival tissues
the vacuum forming unit. When the tray material • 50% reduction in bleaching time.
(5” × 5” sheet) is sufficiently softened by heating, it is Disadvantages of foam liner
adapted slowly over the cast. • Esthetically less pleasing
The tray material is allowed to cool on the casts. It is • Occlusal discrepancies are common
trimmed by scalloping the tray; the tray material should
• Does not help in retention.
cover about 2.0 mm of tissue apical to gingival crest,
both facially and lingually. Second Appointment
Variations in tray fabrication The second appointment involves inserting and fitting
i. Half round bur is used to cut groove along the the tray. The bleaching material is applied into the tray
gingival tooth margin on the cast. as follows:
ii. A trench is built into the tray by stretching a • Two to three drops of bleaching material are placed
into the area of each tooth to be bleached
rectangular rubber band (2.0 × 2.0 mm) around the
crest, centered on the clinical crowns of the teeth.
This trench functions as a reservoir.
• After inserting the tray, the excess material is wiped
out
24

t.me/Dr_Mouayyad_AlbtousH
 432 Essentials of Endodontics

• Patient is instructed not to drink or rinse during

treatment
• The bleaching solution is replaced every one and a
half to two hours during daytime regimen
• A single application of bleaching material is advised
during night
• The daytime regimen requires one to three weeks;
whereas, four to six weeks are required for night time
bleaching.

Third Appointment
Third appointment includes postoperative photo-
graphs, patient’s satisfaction and consent; a decision
whether to continue bleaching or to opt for restorative
treatment or to keep the patient under observation. Fig. 24.7 Removal of gutta-percha and coronal filling

II. NONVITAL TOOTH BLEACHING

The nonvital teeth are discolored because of pulpal
necrosis and related complications. Many a times,
intentional root canal treatment is carried out in deeply
stained (tetracycline stains) teeth so as to bleach the
tooth both from inside and outside. Calcified root canals
without any root canal treatment are also candidates
for nonvital bleaching; however, this modality is
contraindicated in teeth, which are discolored due to
corrosion products and/or large restorations.
The commonly used solutions are:
• Hydrogen peroxide (H2O2)
– Superoxol (30% H2O2)
– Pyrozone (25% H2O2 and ether)
• Sodium perborate (Na2B2O4(OH)4) Fig. 24.8 Placement of barrier

• Sodium percarbonate (2 Na2CO3 · 3 H2O2).

The techniques involved in nonvital bleaching are as
follows.
Preparation of the Tooth
• The restoration, if any, is removed from the coronal a. Thermocatalytic Technique
pulp chamber After preparation of the tooth as described, the
• The access cavity is refined, exposing the surround- technique followed in thermocatalytic nonvital
ing dentin bleaching is practically, the same as for vital tooth
• Approximately 2.0–3.0 mm of obturating material is bleaching. The light and/or heat source is required to
also removed from coronal opening of root canals activate the bleaching solution.
(Fig. 24.7) Technique (Fig. 24.9a to g)
• The tooth is washed with 3.0% H2O2 solution, rinsed • The bleaching agent (superoxol and sodium
with water and dried perborate) separately or in combination soaked in
• 1.5–2.0 mm thick glass-ionomer cement/zinc cotton pellet is placed in the pulp chamber.
phosphate cement is sealed in direct contact with the • The solution is activated using light or heat source
obturation material (acts as a mechanical barrier)
24
(temperature 50–60°C).
(Fig. 24.8) • The solution is kept for 20–30 minutes in one
• The color of the tooth is evaluated and noted. appointment.

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 Bleaching of Discolored Teeth 433

Fig. 24.9a Preoperative Fig. 24.9d Cleaning of pulp chamber

Fig. 24.9b Isolation Fig. 24.9e Placing bleaching agent

Fig. 24.9c Opening of pulp chamber Fig. 24.9f Filling the chamber

Fig. 24.9g Postoperative

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t.me/Dr_Mouayyad_AlbtousH
 434 Essentials of Endodontics

• The process is repeated if required.

• The tooth is rinsed with water. A fresh, sterilized
and dry cotton pellet is placed in the pulp chamber
and sealed with temporary sealing agent.
• The patient is recalled after one to three weeks.
• The color is evaluated after removing the temporary
seal and the cotton. If requisite color is not achieved,
the process can be repeated.
• The final restoration of the cavity is carried out
preferably with composite resin. It is recommended
that acetone based adhesive systems should be used
because these have been shown to reverse the adverse
effects of bleaching on enamel bond strengths.
The thermocatalytic technique has been modified by Fig. 24.10a Preoperative
various investigators. The modifications are:
i. A mixture of one part 95% ethyl alcohol and two
parts chloroform is used for two minutes to desiccate
the dentinoenamel surface. This is followed by
placement of cotton pellet saturated with pyrozone
in the access cavity. A thermocatalytic source is used
to activate the solution for about 20 minutes. After
this, a dressing of 30% H2O2 is placed in the pulp
chamber and sealed with zinc phosphate cement.
ii. The dentinal tubules are dehydrated with 90% ethyl
alcohol. The cotton saturated with superoxol/
pyrozone is placed into the pulp chamber and
activated with a light source for a period of 30–
40 minutes. A vulcanite rubber cone is used to press
the cotton pallet during activation.

b. Walking Bleaching Technique

The bleaching agent is placed in the pulp chamber
(Fig. 24.10a to c) over an extended period of time
Fig. 24.10b Isolation and placing bleaching agent
(24–48 hours to 7–10 days). The commonly employed
agents are superoxol, sodium perborate and their
combinations.

Technique
• A thick paste of sodium perborate and 35% H2O2 is
placed into the pulp chamber
• The access is sealed with a material capable of
providing a good marginal seal (fast setting zinc
oxide eugenol, zinc phosphate cement, glass-
ionomer cement, etc.). The pressure created by these
sealers facilitate bleaching.

c. Modified Walking Bleach Technique

The walking beach technique was modified by Aldecoa
and Mayordomo (1992). After completion of walking

24 bleach technique, a mixture of 10% carbamide peroxide

and sodium perborate is placed in the pulp chamber
for 4 to 6 weeks. Fig. 24.10c Postoperative

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 Bleaching of Discolored Teeth 435

Liebenberg (1997) placed 0.020” poly-propylene A few factors, which can enhance hydrogen based
splint soaked in 10% carbamide peroxide gel in the bleaching are:
access cavity. The splint retained the bleaching agent • Alkaline pH: Hydrogen peroxide is more reactive at
and also prevented ingress of debris into the access alkaline pH (pH above 7). An alkalinizing agent is
cavity. mixed with hydrogen peroxide prior to its applica-
tion to achieve the enhanced effect.
d. Combination Technique • Thermal enhancement: Heating of bleaching agent
(Inside/Outside Bleaching) enhances efficiency of bleaching. The reaction
This technique involves the combined use of thermo- becomes faster and also the penetration of H2O2 into
catalytic in-office nonvital bleaching technique along dental tissues improves (care is exercised, since heat
with nightguard bleaching as in vital tooth bleaching may lead to irreversible damage of the pulp).
(Fig. 24.11). The synergistic effect significantly improves • Photobleaching: Green light is considered optimal for
bleaching. It is indicated where an endodontically photobleaching, since it is not absorbed by hydroxy-
treated tooth is present within an arch and the whole apatite water. It can penetrate deeper, removing
arch is to be bleached. As the nonvital tooth gets chromophores (oxidised color particles) that absorb
bleached, the access cavity is restored with suitable green light. Laser light is more efficient in photo-
composite resin, followed by continuation of night- bleaching.
guard bleaching, if required. • Photolysis: The light is absorbed by a molecule,
effectively breaking down the chemical binding.
III. LASER ASSISTED BLEACHING Hydrogen peroxide, when absorb ultraviolet light,
Laser tooth whitening is not a new phenomenon. The releases hydroxyl ions, which are more potent
procedure utilizes 30–35% hydrogen peroxide, which bleaching agent; enhance the bleaching efficiency.
is applicable in routine bleaching. Laser whitening gel Following dental laser wavelengths have been
is highly processed fumed silica crystals impregnated cleared by the Food and Drug Administration (FDA)
in 35% H2O2. for tooth whitening.
Bleaching gel is applied and is activated by high a. Argon laser (488 nm)
intensity light source/plasma arc light. Crystals in gel b. Carbon dioxide (CO2) laser (10,600 nm)
absorb thermal energy from light, allow dissociation c. Diode laser (980 nm)
and penetration of oxygen into the enamel matrix, thus d. Photochemical laser whitening (smart bleach) (532 nm).
increasing the lightening effect on teeth.
In general, lasers enhance the bleaching effect a. Argon Laser
through photo-oxidation of colored molecules of teeth, Argon lasers are in the form of a blue light with the
which interact with ingredients of bleaching gel via wavelength of 480 nm in the visible part of the
photochemical reactions. spectrum. Such a spectrum having affinity to dark color
ensures easy removal of stains.
The argon laser excites the unstable and reactive
hydrogen peroxide molecule; the energy is absorbed
into intramolecular bonds. The H 2 O 2 molecules
disintegrate into extremely reactive ionic fragments that
combine with the chromophilic structure of the organic
molecules of the tooth tissue, producing simple chemical
chains. The process leads to white tooth surface.
Argon lasers emit photons with short wavelength
(480 nm) and higher energy; fairly effective in bleaching
(higher wavelength laser may create unfavorable pulp
response).

b. Carbon Dioxide (CO2) Laser

The carbon dioxide (CO 2 ) lasers (wavelength of

Fig. 24.11 Inside/outside bleaching (diagrammatic)

10,600 nm) have been used for enhancing the effect of
argon lasers. The effect of initial bleaching with argon
laser is enhanced using CO2 laser.
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t.me/Dr_Mouayyad_AlbtousH
 436 Essentials of Endodontics

The argon laser (emits visible blue light) is used first form of thermal energy. This transfer results in
to activate the bleaching gel. The emitted blue light will controlled heating of the gel and not the tooth, thus
be absorbed by the dark stains and becomes less minimizing the possibility of thermal insult to the
effective as the tooth whitens (the blue light will be dental pulp. This superficial heating of the gel
reflected rather than absorbed by the whiter tooth accelerates the breakdown of H2O2, which boosts the
surface). Then, the CO2 laser (emits invisible infrared free oxygen radicals over a given time.
energy) is used to achieve deeper penetration resulting The currently marketed laser whitening systems are
in more efficient tooth whitening. laser smile whitening system (Biolase) and PearlinBrite
CO2 laser, however, has been discontinued because laser whitening system.
of its thermal effects on the pulp.
IV. TOOTH BLEACHING WITH NONTHERMAL
c. Diode Laser ATMOSPHERIC PLASMA
These are semiconductor lasers with varying wave- Plasma is considered as the fourth state of matter and
lengths; 980 nm wavelength is usually used for it is the most abundant state in the universe. Plasma
bleaching procedure. 38% H2O2 is used as bleaching can be divided into two main categories: hot plasma
agent. (near-equilibrium plasma) and cold plasma (non-
equilibrium plasma). Hot plasma consists of very high
d. Photochemical Laser Whitening (Smart Bleach) temperature particles and they are close to the maximal
Lasers effectively bleach teeth; however, use of 30% degree of ionization. Cold plasma is composed of low
hydrogen peroxide may transiently reduce the temperature particles and relatively high temperature
microhardness of enamel and dentin. It may also result electrons and they have low degree of ionization.
in post-treatment sensitivity. Various investigators (Lee et al 2009) have demons-
With the smart bleach technique (KTP laser) these trated that room temperature plasma could be used for
problems do not occur as the pH of the bleaching gel is tooth bleaching. The authors opined that the tooth
alkaline (approximately 9.5). The primary action of bleaching method with plasma can be complementary
smart bleaching is photochemical and not photo- to conventional method because it provides effective
thermal. The perhydroxyl ion produced, is more bleaching without thermal damage.
reactive than the superoxide and other radicals. Also,
under alkaline conditions, etching of the tooth surface V. OVER THE COUNTER PRODUCTS
does not occur. A considerable number of home tooth whitening
Smart bleach is particularly useful in bleaching products, viz. tooth polish, toothpastes and bleaching
tetracycline stained teeth. The chelate formed between kits are available in the market. Mostly, the tooth polish
tetracycline and hydroxyapatite is a red quinine pro- and toothpastes contain ingredients that remove
duct, dimethylamino tetracycline. This colored product extrinsic stains on teeth rather than bleaching them (a
is relatively resistant to oxidation from peroxide, but few products contain bleaching agents). The removal
can be broken down (photo-oxidised) by green light in of extrinsic stains from teeth by toothpastes (Close up
a particular narrow spectral range (512 to 540 nm). whitening, Amway whitener, Shine and smile, etc.) is
Because this energy aligns particularly well with the mainly achieved by physical means through organic
wavelength of KTP laser (532 nm), energy from this solvents. The ready-made bleaching kits are available
laser can cause terminal photo-oxidation of the quinone with the bleaching agent dispensed in tubes (Colgate
molecule, which renders it colorless. The use of the KTP Platinum).
laser in combination with a hydrogen peroxide based Majority of these products contain surfactants,
gel ensures that complete and irreversible bleaching of peroxide, enzymes, citrate, pyrophosphates and hexa-
red quinone occurs. metaphosphate.
In addition to driving photo-oxidation reactions The major disadvantage is that the abrasive
within the tooth, some of the visible green laser energy constituents not only remove the stains but also abrade
applied to the site is absorbed in Rhodamine B red dye, the tooth structure. This makes the teeth more
which is present in the bleaching gel. The photo- susceptible to further permeability to extrinsic stains
chemical process results in the production of free and internalized stains. Excess and vigorous use of

24 oxygen radicals. A portion of the KTP laser energy

absorbed into the Rhodamine B dye is also transferred
from the excited molecule into the bleaching gel in the
pastes may also lead to hypersensitivity.
The instructions provided in bleaching kits are not
sufficient. The prefabricated trays may not fit accurately

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 Bleaching of Discolored Teeth 437

in the patient’s oral cavity causing occlusal discre- filiform papillae and diffuse mucosal whitening of
pancies, temporomandibular joint dysfunction and tongue.
leaching of the bleaching agent; subsequently, leading iv. Use of hydrogen peroxide may lead to change in
to soft tissue injury. epithelial morphology and its proliferation rate. The
proliferating cell nuclear antigen (PCNA) index, an
ADVERSE EFFECTS OF BLEACHING indication of cell proliferation, increases in basal
The bleaching process, both vital and nonvital, has side and parabasal layers of epithelium. Usually
effects, adversely influencing the tooth and the smokers had a significantly higher PCNA index
surrounding tissues. The adverse effects reported in than nonsmokers, this difference disappeared
animal and human studies include: following bleaching, indicating simulation of cell
a. Hydrogen peroxide toxicity division activity by peroxide similar to that
produced by smoke. It has been established that
b. Cervical root resorption associated with nonvital
10% carbamide peroxide would act as a tumour
bleaching
promoter in the presence of mutated cells.
c. Increased sensitivity associated with vital bleaching
v. Dental pulp is reported to have a low peroxidase
d. Effect on gingiva and mucous membrane
enzyme activity due to a sparse population of
e. Alteration in the structure of enamel fibroblasts. Studies have reported the inhibition as
f. Effect on dentin well as inactivation of pulpal enzymes by H2O2. The
g. Effect on pulp quantity of peroxides penetrating the pulp chamber,
h. Effect on resin-based restorative materials even in small amounts, are sufficient to produce
i. Effect on marginal seal toxic effects on cultured fibroblasts.
j. Vital tooth bleaching may activate caries progression.
b. Cervical Root Resorption associated with
Adverse effects of bleaching Nonvital Bleaching
Vital tooth bleaching • Sensitivity The most commonly seen complication of nonvital
• Alteration in enamel structure bleaching is cervical root resorption (an inflammatory
• Effect on dentin and pulp mediated external resorption of the root). The incidence
• Minor ulceration of gingiva of cervical root resorption after nonvital bleaching
• Caries progression ranges from 0 to 7%. This is more commonly seen in
Nonvital tooth bleaching • Cervical root resorption teeth, which become pulpless at a young age and when
• Effect on marginal seal no barrier is placed between endodontic filling material
General • Hydrogen peroxide toxicity and pulp chamber during bleaching. In such cases, the
and toxicity of other bleaching dentinal tubules remain patent and communicate with
agents periodontal space through the defects of cemento-
• Effect on restorative materials enamel junction. This allows the bleach solution to
reach the periodontal ligament from root canal system
a. Hydrogen Peroxide Toxicity and an inflammatory reaction can be initiated, resulting
Hydrogen peroxide is a toxic product, especially at in external cervical root resorption.
higher concentrations. The adverse effects of hydrogen The features affecting the root resorption are:
peroxide are: • 10% of anterior teeth have cervical areas in which
i. Hydrogen peroxide can cause burns on contact with enamel and cementum do not meet
skin or eyes. When 30% H2O2 was applied to the • Cervical resorption occurs coronal to the endodontic
tip of rat tongue at 15 minute intervals (four seal.
applications), it lead to edema. However, prior The critical region for the root resorption is the
application of catalase may prevent such edema. proximal area, where the cementoenamel junction dips
ii. The inadvertent flow of H2O2 into the periodontal and cervical root resorption begins. Location, shape and
ligament and periapical tissues during root canal the barrier between endodontic filling material and the
treatment, produce effervescence and liberate pulp chamber can effectively curtail this problem.
oxygen; may lead to tissue emphysema. The barrier placement involves periodontal probing
iii. The adverse effects of hydrogen peroxide mouth
rinses (6% H 2O2) include mouth irritation and
discomfort, dryness, loss of taste, elongation of
from three sides, viz. labial, mesial and distal. The
probing is carried out from the epithelial attachment
to the labial contour of the tooth followed by mesial
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t.me/Dr_Mouayyad_AlbtousH
 438 Essentials of Endodontics

and distal. The internal level of barrier should be one or through bleaching agents leaking onto gingival soft
millimeter incisal to the corresponding external probing tissues. Higher concentration of H2O2 produce soft tissue
of the epithelial attachment. burns; the color changes to white. It is hypothesized
The intention of barrier placement is to cover dentinal that rehydration and application of antiseptic ointment
tubules apical to the epithelial attachment so that the return the color to its original. Effective protection of
bleaching agents are contained within the pulp chamber. gingiva and mucosa, with good isolation will minimize
Cavit and light cure glass-ionomer cements are the the risk of irritation.
most commonly used barrier materials. The barrier must be checked for any sign of leakage.
The barrier should cover all buccal gingival surface. In
c. Increased Sensitivity associated with Vital Bleaching case of ulceration, the site is extensively washed with
Vital tooth bleaching uses high concentration of water and/or the anesthetic solution. In severe cases,
hydrogen peroxide (35–50%) or carbamide peroxide vitamin E can be applied over the ulceration, which will
(35–40%), often supplemented with a heat source; or in help healing the wound. The position of light should also
a bleaching tray to be used at home. be adjusted; should not be too near to mucous membrane.
The exact mechanism of tooth sensitivity is not clear;
however, on the basis of in vitro studies, it is assumed e. Alteration in the Structure of Enamel
that H2O2 in the bleaching gel is capable of penetrating Vital tooth bleaching using carbamide peroxide or
through enamel and dentin and reaching the pulp hydrogen peroxide significantly alters enamel topo-
chamber. graphy. High concentrations of carbamide peroxide
It has been established that the bleaching procedure damage enamel surface integrity; however, lesser than
increases intrapulpal temperature, which is detrimental phosphoric acid etch. As a result of this increased
to pulp. The heat when applied to hydrogen peroxide surface roughness, the teeth may be more susceptible
may lead to diffusion of H2O2 into dentin and pulp. to extrinsic discoloration after bleaching. A few studies
However, inflammatory changes get recovered within have reported that after bleaching, enamel gets
one month. weakened by oxidation of organic/inorganic elements,
In-office bleaching procedures with high concentra- which may appear as porous or pitted surface. The
tions of hydrogen peroxide were associated with high oxygen radicals released from peroxide bleaching
post-treatment sensitivity; however, nightguard material may affect chemical structure of enamel,
bleaching with lower concentration of hydrogen reducing calcium/phosphate ratio, enamel micro-
peroxide (3.0%) or carbamide peroxide (10%) has hardness and surface morphology; subsequently, lead
resulted in decreased sensitivity. to increased caries risk. Various studies have also
The pH of the bleaching agent and desiccation of the confirmed that use of 10% carbamide peroxide daily
tooth surface are causative agents for sensitivity. for six months did not adversely affect the surface
Potassium nitrate and sodium fluoride when added to texture of human enamel.
10% carbamide peroxide, considerably reduce sensiti-
vity without any significant change in bleaching results. f. Effect on Dentin
Use of anti-inflammatory drugs prior to bleaching may Bleaching agents effect tooth color (primarily of dentin).
also be effective. McCaslin et al (1999) placed 10% carbamide peroxide
Tooth sensitivity is a common adverse effect of directly on enamel and observed a uniform color
external tooth bleaching. Various studies have change throughout the dentin surface.
confirmed that use of 10% carbamide peroxide had led The majority of studies investigating surface
to increased tooth sensitivity in at least 50% of the morphology of dentin found no significant changes.
patients. Higher incidences of tooth sensitivity (65–78%) However, Zalkind et al (1996) found that Ca and PO4
have been reported after bleaching with H 2 O 2 in ions ratio of dentin was modified following 7 days of
combination with heat. continuous treatment with 30% H2O2 or 10% carbamide
Tooth bleaching in younger individuals (less than peroxide solutions.
18 years) should be avoided; and also on teeth with A transient decrease in surface micro hardness has
caries, exposed dentin and/or defective restorations. been observed; however, it is recovered following
treatment with 0.05 fluoride solution.
d. Effect on Gingiva and Mucous Membrane
24 Bleaching trays which are ill-fitting, overextended, or
not properly trimmed, can irritate soft tissue directly
It is established that oxygen radicals damage the
dentin substrate (hybrid layer), which is mainly
responsible for adhesion of composite resin to dentin

t.me/Dr_Mouayyad_AlbtousH
 Bleaching of Discolored Teeth 439

surface. Recent studies have also confirmed that the j. Vital Tooth Bleaching may
durability of adhesive restorations are detrimentally activate Caries Progression
influenced by carbamide peroxide bleaching. It is It is established that vital bleaching alters surface
concluded that the damage caused to restoration-dental enamel structure (pitting, etc.). Such altered enamel
tissue bond strength by the bleaching agent is surface becomes the potential sites for caries pro-
proportional to the increase in carbamide peroxide gression.
concentration; the dentin-composite bond was less
sensitive as compared to enamel-composite bond.
BIBLIOGRAPHY
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causing transient reduction in pulpal blood circulation vitro study. Clin. Oral Investig.: 2011; 15:673–680.
and occlusion of pulpal blood vessels. The most 2. Almas K and Al-Harbi M. The effect of 10% carbamide
common side effect experienced by patients using home peroxide home bleaching system on the gingival health. J.
bleaching technique is mild, transient temperature Contemp. Dent. Pract.: 2003; 1:32.
sensitivity. This sensitivity appears to be dose-related 3. Alonsodela V and Balboa CO. Comparison of the clinical
rather than pH related. efficacy and safety of carbamide peroxide and Hydrogen
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h. Effects on Resin-based Restorative Materials 4. Alqahtani MQ. Tooth-bleaching procedures and their
controversial effects: A literature review. Saudi Dent. J.: 2014;
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effective in reversing the compromised bonding of carbamide peroxide, carbopol and/or glycerine on enamel
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carbamide peroxide. 9. Bortolatto JF, Pretel H and Floros MC. Low concentration
It has been established that sodium ascorbate gel H2O2/TiO-N in-office bleaching: a randomized clinical trial.
when applied following bleaching increased the resin- J. Dent. Res.: 2014; 93:66S–71S.
enamel bond strength (the increase was proportional 10. Briso A, Forseca M, de Almeida L, Mauro S and Dos SP.
to the duration of application). Color alteration in teeth subjected to different bleaching
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A few authors opined that use of catalase or catalase
like substances can effectively neutralize the residual 11. Browning WD, Chan DC, Frazier KB and Callan RS. Safety
and efficacy of a nightguard bleaching agent containing
hydrogen peroxide on the bleached teeth. α-tocopherol
sodium fluoride and potassium nitrate. Quint. Int.: 2004; 4:26.
and grape seed extract have also been found to be
effective. It is recommended to postpone the bonding 12. Buchalla W and Attin T. External bleaching therapy with
activation by heat, light or laser - a systematic review. Dent.
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24 hours to four weeks have been quoted in various
13. Burrows S. A review of the safety of tooth bleaching. Dent.
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Update: 2009; 36:604.

i. Effect on Marginal Seal 14. Dahl JE and Pallesen U. Tooth bleaching—a critical review
of the biological aspects. Crit. Rev. Oral Biol. Med.: 2003;
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marginal seal leading to marginal leakage. Various 15. D’Arce M, Lima D, Aguiar F, Ambrosano G, Munin E and
studies have concluded that use of mouthrinses (Oral-
B, Listerine, etc.) after bleaching can increase post-
restoration microleakage of composite restorations.
Lovadino J. Evaluation of ultrasound and light sources as
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2012; 7:176.
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 440 Essentials of Endodontics

16. De Moor RJG, Verheyen J, Diachuk A, Verheyen P, Meire 38. Markowitz K. Pretty painful: why does tooth bleaching hurt?
MA, De Coster PJ, Keulemans F, De Bruyne M and Walsh LJ. Med. Hypotheses.: 2010; 74:835–840.
Insight in the chemistry of laser-activated dental bleaching. 39. Meincke DK, Prado M, Gomes BP, Bona AD and Sousa EL.
The Scientific World J.: 2015; Article ID650492:1–6. Effect of endodontic sealers on tooth color. J. Dent.: 2013;
17. Deliperi S, Bardwell DN and Papathanasiou A. Clinical 41:93–96.
evaluation of a combined in-office and take home bleaching 40. Mokhlio GR, Matis BA, Cochrm MA and Eckert GJ. A clinical
system. JADA: 2004; 135:628. evaluation of carbamide peroxide and hydrogen peroxide
18. Dias HB, Carrera ET, Bortolatto JF, de Andrade MF and de whitening agents during daytime. JADA: 2000; 131:1269.
Souza RAN. LED and low level laser therapy association in 41. Naik S, Tredwin CJ and Scully C. H2O2 tooth-whitening
tooth bleaching using a novel low concentration H2O2/N- (bleaching): Review of study in relation to possible
doped TiO2 bleaching agent. Laser Physics: 2015; 26:015602. carcinogenesis. Oral Oncology: 2006; 42:668.
19. Dietschi D, Rossier S and Krejci I. In vitro calorimetric 42. Nam SH, Lee HJ, Hong JW and Kim GC. Efficacy of non-
evaluation of the efficacy of various bleaching methods and thermal atmospheric pressure plasma for tooth bleaching. The
products. Quint. Int.: 2006; 37:515. Sci. World J.: 2015; Article ID 581731.
20. Felman D and Parashos P. Coronal tooth discoloration and
43. Pan J, Yang X and Sun K. Tooth bleaching using low
white mineral trioxide aggregate. J. Endod.: 2013; 39:484–487.
concentrations of hydrogen peroxide in the presence of a
21. Fernandez E and Bortolatto J. New trends on in-office tooth non-thermal plasma jet. IEEE Transactions on Plasma Science:
bleaching. J. Dent. Sci. and Ther.: 2016; 1:26–28. 2013; 41:325–329.
22. Gianluca G, Luca T and Giovanni D. Clinical evaluation of a
44. Presoto CD, Bortolatto JF, de Carvalho PPF, Trevisan TC,
novel liquid tooth whitening gel. Am. J. Dent.: 2003; 16:147.
Floros MC and de Oliveira OB. New parameter for in-office
23. Goldberg M, Grootveld M and Lynch E. Undesirable and dental bleaching. Case Report in Dent.: 2016; Article ID
adverse effects of tooth-whitening products: a review. Clic. 6034757, 1–4.
Oral Invest.: 2010; 14:1.
45. Pretty IA, Ellwood RP, Brunton PA and Aminian A. Vital tooth
24. Heymann HO. Tooth whitening: facts and fallacies. Br. Dent.
bleaching in dental practice: 1. Professional bleaching. Dent.
J.: 2005; 198:5–14.
Update: 2006; 33:293.
25. Joiner A. Review of the effects of peroxide on enamel and
46. Soares DG, Marcomini N, Basso FG, Pansani TN, Hebling J
dentin properties. J. Dent.: 2007; 35:889.
and de Sourza CA. Indirect cyto-compatibility of a low-
26. Joiner A. The bleaching of teeth: a review of the literature. J. concentration hydrogen peroxide bleaching gel to
Dent.: 2006; 34:412–419. odontoblast-like cells. Int. Endod. J.: 2016; 49:26–36.
27. Joiner A. Tooth color: a review of the literature. J. Dent.: 2004;
47. Souza GDM, Santos LM, Fernandes CA, Dantas EDV, Galvao
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MR, de Assuncao IV and Borges BCD. Sensitivity in dental
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Dent.: 2016; 6:3–13. 2014; 2:1023.
29. Kielbasa AM, Maire M, Gieren AK and Eliav E. Tooth sensi-
48. Sulieman M. An overview of tooth discoloration: Extrinsic,
tivity during and after vital tooth bleaching: A systematic
intrinsic and internalized stains. Dent. Update: 2005; 32:463.
review on an unsolved problem. Quint. Int.: 2015; 46:881–97.
49. Sulieman M. An overview of two bleaching techniques:
30. Kihn PW. Vital tooth bleaching. Dent. Clinic. North Am.:
Nightguard vital bleaching and non-vital bleaching. Dent.
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Update: 2005; 32:37.
31. Kwon SR and Wertz PW. Review of the mechanism of tooth
whitening. J. Esthet. Restor. Dent.: 2015; 27:240–257. 50. Toh CG. Clinical evaluation of a dual activated bleaching
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32. Kwon SR. Whitening the single discolored tooth. Dent. Clinic.
North Am.: 2011; 55:229. 51. Tredwin CJ, Naik S, Lewis NJ and Scully C. Hydrogen
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Atmospheric pressure plasma jet composed of three Odontology: 2005; 93:52.
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and Polymers: 2010; 7:274–280. treatment using KTP Laser assisted tooth whitening. J. Oral
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G. Tooth discoloration induced by endodontic materials: a 54. Watts A and Addy M. Tooth discoloration and staining: A
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Zahnmed: 2010; 120:306–313.

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 Chapter
25
Vital Pulp Therapy

Importance of dental pulp in a healthy tooth is c. Deep tooth preparation where remaining dentin
unquestionable. It provides inductive, formative, thickness is less than 2.0 mm
nutritive, protective and reparative function. Through- d. Crack through body of tooth
out the life of the tooth, it forms secondary, reparative e. Barometric changes leading to aerodontalgia
and sclerotic dentin. Vital pulp is essential for routine f. Orthodontic movement of heavily restored abutment
functioning. Endodontic treatment carried out in non- teeth.
vital teeth is not free of side effects. Therefore, every
precaution should be taken to preserve the vitality of B. Thermal
tooth. The defense cells in the dental pulp and potential Slight rise in intrapulpal temperature (100°F) affects pulp.
new odontoblasts can form reparative dentin The following factors raise the intrapulpal temperature.
maintaining the pulp vitality. • Heat from cavity preparation (with coolant)
It has been observed that when local inflammation • Setting of cements leading to an exothermic reaction
is induced in the pulp, the tissue pressure increases only • Inadequate pulp protection beneath metallic
in inflamed area. This fluid is absorbed into capillaries restorations
in adjacent uninflamed tissues resulting in increased • Polishing of restorations
lymphatic drainage. The healing process usually
• Impression materials.
prevails when injurious agents are removed and
therapeutic measures are instituted. C. Chemical
• Dental materials with high acidity
Etiology of Pulpal Diseases
• Irritants like resin monomers
A. Mechanical • Erosion with acids
a. Trauma – Soft drinks
i. Accidental – Gastrooesophageal reflux.
ii. Parafunctional habits
D. Bacterial
• Bruxism
• Caries
• Bruxomania
• Trauma leading to direct invasion of bacteria in pulp
• Clenching
• Systemic (anachoresis)
iii. Iatrogenic dental procedures • Chronic periodontal diseases.
• Tooth preparation
• Pins Healthy Pulp and Primary Trauma
• Malleting gold foil The sequelae of trauma to the healthy pulp is described
iv. Chronic trauma from occlusion in Flowchart 25.1.
b. Pathologic wear Clinical Status of Pulp
i. Attrition The healthy pulp, under the influence of above-
ii. Abrasion mentioned factors, may get stressed, inflamed or
iii. Abfraction necrosed. The stressed pulp is a clinical concept and

441

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 442 Essentials of Endodontics

Flowchart 25.1: Sequelae of trauma to the healthy pulp

not a histologic entity. Although stressed pulp is usually The clinical evaluation of healthy, stressed, inflamed
asymptomatic clinically, it may deteriorate rapidly to and necrotic pulp is tabulated in Table 25.1.
a diseased condition. Crown preparations, pin
buildups, restorative failures and tooth structure cracks VITAL PULP THERAPY
can transform the pulp from a state of asymptomatic It is the treatment of an exposed or nearly exposed pulp
stress to a state of pulpal disease. by a medicament to repair and maintain its vitality.

Table 25.1 Clinical evaluation of healthy, stressed, inflamed and necrotic pulp
Clinical evaluation Healthy pulp Stressed pulp Inflamed pulp Necrotic pulp
Patient’s history • No significant dental • Asymptomatic (no pain) • Symptomatic (pain) • Usually no pain or pain
history • History of long dental • Previous complex dental on mastication only
• Effective mastication procedures, caries or history • Pain with hot stimulus
after dental procedures trauma
Radiographic • Well-defined pulp cham- • Deep restorations or • Pulp chamber recession • May show any of the
features ber and root canals caries • Narrow pulp chamber findings of healthy,
• Acceptable remaining • Pulp spaces altered (partial calcification) inflamed or stressed
dentin by calcification or • Deep restorations pulp
• No calcification internal resorption
Examination of teeth • Minimal caries or • Normal surrounding • Defective restorations/ • May show any of the
and surrounding restorations tissues multiple restorations findings of healthy,
tissues • Normal color of tooth • Teeth normal • Surrounding tissues may inflamed or stressed
and surrounding tissues be normal pulp
Pulp response to • Nil • Very rapid or very late • Late, weak, inconsistent • No response to stimuli

25
external stimuli response, provoked on response requiring high • Sometimes pain with
stimulus and may linger degree of stimulation hot stimulus
on and longer time

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 Vital Pulp Therapy 443

Vital pulp therapy has a high success rate under i. Infected dentin: It is necrotic, soft dentin, not painful
following conditions: to stimulation and grossly infected with bacteria.
• Pulp is not inflamed. Collagen is irreversibly denatured.
• Hemorrhage is properly controlled. ii. Affected dentin: It is demineralized, discolored but
• Application of nontoxic capping material. hard dentin, painful to stimulation containing very
• Capping material and restoration able to seal out few bacteria. It is reversibly denatured and capable
bacteria. of being remineralized.
When outer layer is removed, most of the bacteria
Vital pulp therapy includes following treatment are removed and the substrate on which they thrive is
modalities: also removed. When cavity is sealed with a suitable
1. Indirect pulp capping/indirect pulp treatment material, any remaining bacteria are either killed or lie
2. Direct pulp capping in a stage of dormancy. However, affected dentin can
3. Pulp curettage be left on pulpal and axial walls and never on dentino-
4. Partial pulpotomy enamel junction and cavity margins. The two layers can
5. Pulpotomy be differentiated with either 0.5% basic fuchsin or 1.0%
acid red dyes. Acid red is preferred since basic fuchsin
6. Apexogenesis (physiological root formation).
has carcinogenic potential.
Apexification, a procedure, wherein root closure/
The remaining dentin thickness also plays an impor-
apical barrier is achieved in nonvital teeth with
tant role. If remaining dentin thickness is more than
incompletely formed root apex, is also described.
1.0 mm, no significant disturbance in the pulp is seen.
1. Indirect Pulp Capping/Indirect Pulp Treatment 0.25 to 0.5 mm remaining dentin leads to maximal
reparative dentin formation and remineralization of
Indirect pulp capping implies treating pulps, which are
demineralized dentin; whereas, 0.25 mm or less
not exposed and may be near exposure; whereas,
remaining dentin provoke bacterial growth in pulp.
indirect pulp treatment is a technique in which an effort
Reparative dentin formation and remineralization is
is made to avoid pulp exposure during the treatment
greatly decreased.
of teeth with deep carious lesions without any evidence
of pulp degeneration or periapical pathology. Technique
Indirect pulp capping is two appointment procedure,
The technique involves the following steps:
whereas indirect pulp treatment is a single appointment
procedure. A. Removal of caries
Indication a. Mechanical method
• Deep carious lesion with minimal pulpal inflamma- • Soft caries can be removed with a spoon excavator
tion (complete removal of caries may lead to pulp by removing flakes of carious dentin in layers.
exposure). • The discolored dentin can be removed with large
round steel burs revolving at slow speed. Pulp
Contraindications damage may result from reaction of frictional heat
• A tooth with existing pulp inflammation with the use of bur while excessive pressure with a
• A tooth with periapical pathology. spoon excavator may force the microorganism into
the dentinal tubules or expose the pulp. Removal of
Objectives
infected dentin should continue until the remaining
• Minimize pulp injury dentin feels as hard as normal dentin.
• Promote dentin sclerosis
• Minimize postoperative sensitivity b. Chemomechanical methods
• Arrest progression of carious lesion The conventional caries excavation methods usually
induce pain and fear in patients, especially the children.
• Stimulation of reparative dentin formation
To make the caries removal painless, selectively
• Remineralize affected dentin.
softening the carious lesion will facilitate removal by
Rationale excavation without any pressure.
In a carious lesion, dentin decalcification precedes
bacterial invasion within dentin. In an active carious
lesion, two distinct layers are seen:
The chemical agents used to soften dentin are:
i. Sodium hypochlorite-based agents: Earlier 5.0% sodium
hypochlorite has been used to soften carious lesions.
25

t.me/Dr_Mouayyad_AlbtousH
 444 Essentials of Endodontics

Later, the use of 5.0% sodium hypochlorite was The etch pattern of dentin in Carisolv-excavated lesions
observed to be toxic to adjacent healthy tissues. A new is deeper than caries removed with a conventional bur.
solution, GK-101 was developed, which consisted of Carisolv excavated dentin shows better bonding
sodium hydroxide, sodium chloride and glycine in characteristics, viz. patent dentinal tubules, not covered
addition to 5.0% sodium hypochlorite. GK-101 was by smear layer, irregular surface and the improved
more effective than the hypochlorite alone; however, wetting potential. Carisolv has superior property in
the carious softening effect was very slow. reducing the counts of viable bacteria in residual dentin,
Caridex, a commercial preparation, is consisted of as compared to conventional bur excavation. Carisolv
sodium hypochlorite solution buffered with mixture of has bactericidal activity due to formation of chloramines
aminobutyric acid, sodium chloride and sodium compounds. The disadvantages include its high cost and
hydroxide. The ability of sodium hypochlorite to need of special instruments. Children usually dislike
selectively soften carious lesion is attributed to the the chlorine taste and odor (Table 25.2).
buffering effect of the amino acids, which enhances
ii. Pepsin-based agents: An enzyme pepsin in a
disrupting effect on the degenerated collagen of the
phosphoric acid/sodium bisphosphate buffer has also
carious dentin. The resultant friable collagen fibrils can
been tried as a chemical agent to soften caries. SFC-
be easily removed with excavators.
VIII (3M ESPE, Germany) is the commercially available
Caridex was not fully successful in clinical practice
pepsin based agent. The advantage of this pepsin-based
because of the need for a specific apparatus to deliver
agent is that it acts on more specific denatured collagen
the solution into the cavity, short shelf-life, longer
than the sodium hypochlorite-based agents. The
treatment time, and higher treatment cost.
phosphoric acid dissolves the inorganic component of
Another caries removing chemical agent based on
carious dentin, while at the same time pepsin gets access
sodium hypochlorite was introduced in the name of
to the organic part of the carious mass, selectively
Carisolv. It is available in the form of a gel. It consists of
dissolving the denatured collagen. For effective caries
two components, one is transparent liquid containing
removal, SFC-VIII gel should be used along with an
0.5% sodium hypochlorite and the other component
excavator having hardness between that of sound and
contain an amino acid mixture (glutamic acid, leucine
infected dentin. The limitation of SFC-VIII excavation
and lysine), sodium carboxymethyl cellulose to enhance
is that the heavily pigmented and arrested dentin caries
the viscosity; sodium hydroxide provide pH of 11 and
pose problem in pepsin digestion.
water acts as vehicle.
The chemical composition and microstructure of iii. Papacarie: Papacarie (Sao Paulo-Brazil) is another
dentin after excavation with Carisolv remained chemomechanical caries removing agent, which
unchanged. The calcium and phosphorus content contains papain, chloramines, toluidine blue and certain
remain similar after excavation; however, the hardness salts. Papain is a proteolytic enzyme similar to pepsin.
values of residual dentin were same as for sound dentin. Papain comes from latex of leaves and fruits of green

Table 25.2 Comparison of Caridex and Carisolv

Characteristics Caridex Carisolv
Composition Solution I: 1.0% sodium hypochlorite Solution I: 0.5% sodium hypochlorite
Solution II: Solution II:
i. 0.1M glycine aminobutyric acid i. 0.1M glutamic acid/leucine/lysine
ii. 0.1M sodium chloride ii. Sodium carboxymethyl cellulose
iii. 0.1M sodium hydroxide iii. Sodium hydroxide
Dye Nil Erythrocin pink
pH 11 11
Physical form Liquid Gel
Volume needed 100–500 ml 0.2–1.0 ml
Time required 5 to 15 minutes 5 to 15 minutes
Activity after mixing Remains active up to one hour Remains active up to 20 minutes
Biocompatibility No adverse effects No adverse effects

25 Bactericidal activity
Bonding characteristics
Satisfactory
Satisfactory bonding
Much better
Better bonding characteristics

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 Vital Pulp Therapy 445

adult papaya, (carica papaya). Papacarie is available in cement or a glass-ionomer cement to achieve a good seal
syringes having 3.0 ml gel. The papacarie gel is allowed (Fig. 25.1c). This seal should not be disturbed for 6–8
to act in a cavity for 60 seconds. As the collagen fibrils weeks, as the carious process in the deeper layer gets
gel dissolved, the clear gel becomes dark in color. The arrested.
papain digests dead cells and breaks the partially
degraded collagen molecules, contributing to the 2nd Sitting (6–8 Weeks Later)
degradation of the collagen fibrils formed by the carious In the second sitting, all temporary filling material,
process. especially calcium hydroxide dressing over deep
portions of the cavity floor is removed. The color
iv. Carie-care: It is an enzyme derived from papaya
changes from deep red rose to light gray/light brown;
plant, “the Carica Papaya”. It is composed of papaya
the texture would change from spongy-wet to hard and
extract, therapeutic essential oil, coloring gel, sterile
caries appears to be dehydrated. Thus, the remaining
water, chloramines and sodium chloride.
affected carious dentin appearing dehydrated and
Carie-care (papain) acts on the carious tissue, which “flaky” can be easily removed. Do not disturb pre-
lacks alpha-antitrypsin (a plasmatic antiprotease dentin, which is the area around the potential exposure
system, which inhibits proteolysis). The absence of anti- appearing whitish and may be soft. The cavity
protease allows papain to act on the partially degraded preparation should be restored in the similar way as
collagen by breaking the peptide bonds. In addition to 1st sitting.
papain, the chloramine dissolves carious dentin by
means of chlorination of the partially degraded Re-enter or not?
collagen. The gel also contains therapeutic oils (clove
The re-entry restorative procedure is still questionable.
oil), which induce analgesic and antiseptic action. It
It is recommended only if the tooth is asymptomatic,
minimizes pain sensation and has a pleasant taste,
surrounding soft tissues are free from swelling,
acceptable by children and the adults as well.
temporary filling is intact, bitewing radiographs of the
The procedure is explained in detail in Chapter 15, Dental treated tooth shows the presence of reparative dentin.
Caries book by the author—Vimal Sikri. Research has shown that carious dentin will re-
mineralize within the restoration. So, if “all system go”
Two-Appointment Technique (Indirect Pulp Capping)
on recall, the restoration should not be redone.
1st Sitting With re-entry there could be a risk of creating pulp
Local anesthesia is administered and the tooth is exposure and further insult to the pulp. If a pulp expo-
isolated with a rubber dam. Cavity outline is established sure occurs during re-entry, a more invasive vital pulp
with a high-speed handpiece. Peripheral carious therapy techniques, such as direct pulp capping or
dentin/infected dentin should be removed with sharp pulpotomy would be indicated.
spoon excavators (Cohen recommends the use of a large
round bur for better results) (Fig. 25.1a). Cavity should One Appointment Technique
be irrigated and dried with cotton, followed by (Indirect Pulp Treatment)
placement of hard setting calcium hydroxide over the One appointment indirect pulp capping is termed
remaining affected dentin (Fig. 25.1b). The remainder indirect pulp treatment. The selection for one
of the cavity is filled with reinforced zinc oxide eugenol appointment indirect pulp treatment must be based on

Fig. 25.1 Indirect pulp capping: (a) Carious lesion near pulp (pulp not exposed); (b) Placement of calcium hydroxide on
affected dentin; (c) Tooth restored after formation of reparative dentin
25

t.me/Dr_Mouayyad_AlbtousH
 446 Essentials of Endodontics

clinical judgment and experience with many cases. In during tooth preparation can be successfully treated;
recent years, rather than complete caries removal in two whereas, exposure caused by caries usually need root
appointments, the focus has been to excavate caries canal treatment. The younger the patient, the better are
as close as possible to the pulp, i.e. some caries be left the chances of healing and repair.
in the tooth to avoid an exposure, placement of a
protective liner, and restoring the tooth without a Indications
subsequent re-entry to remove any remaining affected • Size of exposure should be less than 0.5 mm.
dentin. • No profuse hemorrhage or serous/purulent exudate.
• In case of trauma, exposure should not be more than
Stepwise Excavation a few hours old.
The stepwise excavation of deep caries has shown • Nontender to percussion (a recently traumatized
promising results in managing reversible pulpitis tooth may be reversibly tender to percussion).
without pulpal perforation and/or endodontic therapy.
This approach involves a 2-step process. Contraindications
i. The first step is the removal of carious dentin along • Instrument has penetrated the pulp; infected dentin
the dentinoenamel junction (DEJ) and excavation of chips may settle in the pulp.
only the outermost infected dentin, leaving a carious • Periodontally involved tooth.
mass over the pulp. The objective is to change the • Symptoms of irreversible pulpitis.
cariogenic environment in order to decrease the
number of bacteria, close the remaining caries from Requirements
the biofilm of the oral cavity, and slow arrest the Ideal requirements for pulp capping material are:
caries development.
• Stimulate reparative dentin formation
ii. The second step is the removal of the remaining
• Maintain pulp vitality
caries and placement of a final restoration. The most
common recommendation for the interval between • Bactericidal/bacteriostatic
steps is 3–6 months, allowing sufficient time for the • Release fluoride to prevent secondary caries
formation of tertiary dentin and a definitive pulpal • Adhere to dentin/restorative material
diagnosis. Critical to both steps of excavation is the • Resist forces during restoration placement and
placement of a well-sealed restoration. thereafter functional forces
The research is inconclusive as regard the decision • Provide appropriate seal
to use one-appointment caries excavation or stepwise • Radiopaque.
technique. The decision should be based on the
individual patient circumstances. Technique
Atraumatic restorative technique (ART) is considered Tooth is isolated with rubber dam. Caries, if present,
as one form of indirect pulp treatment. The procedure are removed from side walls using spoon excavators
is based on excavating and removing caries using hand (Fig. 25.2a). The exposed pulp is not allowed to dry.
instruments only and then restoring the tooth with an The exposed site is washed with weak disinfectant and
adhesive filling material. covered with a moist cotton pellet dipped in disinfectant
solution. Bleeding is controlled with 5.0% sodium
B. Pulp protection
hypochlorite. After controlling bleeding, pulp capping
The open dentinal tubules after the removal of caries material is placed (Fig. 25.2b). It is placed with little
need to be completely sealed to minimize ingress of pressure, because with heavy pressure displacement
bacteria, which may hinder pulp repair process. The of capping material/dentin chips into the pulp may lead
materials used for pulp protection (pulp capping to further pulpal damage. It is followed by a restoration
materials) are described in subsequent pages. that seals the tooth from microleakage (Fig. 25.2c). It is
established that bacterial leakage is responsible for
2. Direct Pulp Capping pulpal response rather than toxicity of materials, which
Direct pulp capping implies treating exposed pulps. It results in only mild and transitory pulpal response.
is defined as ‘treatment of an exposed vital pulp by sealing Hypersensitivity to temperature change may persist for

25 the pulp wound with an appropriate material to facilitate

formation of reparative dentin and maintenance of vital pulp’.
Exposure caused by trauma or by operator’s fault
a day or so. Tooth is tested periodically for pulp vitality.
Symptoms usually subside in 4–6 weeks. If tooth
remains vital, a permanent restoration may be placed.

t.me/Dr_Mouayyad_AlbtousH
 Vital Pulp Therapy 447

Fig. 25.2 Direct pulp capping: (a) Carious lesion leading to pin-point exposure of pulp; (b) Placement of calcium hydroxide
on exposed pulp; (c) Tooth restored after formation of reparative dentin

If tooth becomes painful, or exhibits decreased p. Dentin shavings

reading on vitality testing or becomes nonvital, root q. Tricalcium phosphate
canal treatment becomes mandatory. r. Laser
s. Miscellaneous
Pulp Capping: Key points
• Avoid exposing the pulp Other techniques for pulp tissue excision and
• Even if residual caries present, cover carious dentin and seal disinfection are:
properly • Laser
• Follow-up for at least six weeks for any symptoms • Electrosurgery
• If pulp gets exposed, control hemorrhage with appropriate
astringent agents (sodium hypochlorite is effective hemostatic a. Zinc oxide eugenol
agent and is also antibacterial) The use of zinc oxide eugenol as pulp capping agent is
• Calcium hydroxide and mineral trioxide aggregate (MTA) are controversial. It does provide anodyne effect to the
suitable pulp capping agents
pulp. Because of better marginal adaptability, it
• Newer agents, such as morphogenic proteins, enzymes, plant
provides environment for pulp healing; may not induce
extracts, resorcinol, etc. are also effective
calcific bridge formation.
• Zinc oxide eugenol, glass-ionomer cement and bonding agents
are not successful (should be avoided) b. Calcium hydroxide
• The cavity should be sealed immediately after pulp capping;
protect underlying tissues from leakage and bacterial Hermann (1930) demonstrated that when vital pulps
contamination were covered with calcium hydroxide, it led to the
• The tooth should be assessed clinically and radiologically at formation of secondary dentin. Calcium hydroxide,
periodic intervals; restore with suitable restorative material applied directly to pulp tissue lead to coagulation
necrosis of the adjacent tissues. Beneath the region of
The materials used as pulp capping are: coagulation necrosis, cells of underlying pulp
a. Zinc oxide eugenol differentiate into odontoblast and other cells, which
b. Calcium hydroxide help to form dentin matrix. However, a blood clot
c. Mineral trioxide aggregate (MTA) should not be left between calcium hydroxide and pulp.
d. Bonding agents Such cases, (hydroxyl ions trapped in the clot) do not
e. Resin-resorcinol allow differentiation of odontoblasts.
f. Polycarboxylate cement Calcium hydroxide maintains a local state of
g. Cyanoacrylates alkalinity necessary for bone/dentin formation. Earlier,
h. Antibiotics and corticosteroids it was postulated that calcium (Ca) from calcium
hydroxide would diffuse into pulp and participate in
i. Growth factors
the formation of reparative dentin. Later, it was
j. Enzymes
established that calcium ions from calcium hydroxide
k. Stem cells do not help formation of new dentin; however, it may
l. Propolis come from blood. Commercially available pastes of
m. Emdogain
n. TheraCal LC
o. Biodentine
calcium hydroxide are less alkaline and less caustic; a
bridge is formed in contact with capping material and
some of the tissue underlying the bridge may get
25

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 448 Essentials of Endodontics

degenerated/resorbed, leaving a void between capping c. Mineral trioxide aggregate (MTA)

material and the dentin bridge. Under calcium Mineral trioxide aggregate (MTA), a modified Portland
hydroxide dressings, an area of necrosis is formed on cement, is an accepted and successful alternative to
the surface of the pulp stump. Beyond the area of calcium hydroxide. It is of three types, gray, white and
induced necrosis, undifferentiated mesenchymal cells modified. The composition of three types is tabulated
in the cell rich zone proliferate and differentiate into in Table 25.3.
odontoblasts. Another theory says that new odonto- MTA is mixed according to manufacturer’s
blasts develop from fibroblasts. In case of severe instructions (MTA: H2O is 3 : 1) to the consistency of
inflammation, reparative dentin devoid of dentinal wet sand. It is carried to the pulp surface with a spoon
tubules is formed. In case of mild inflammation, varying excavator or MTA carrier gun. It is patted down with a
number of dentinal tubules are present. Calcium moist cotton pellet. 1.5 mm thick layer of MTA is
hydroxide induced dentinal bridge contains multiple considered effective pulp capping agent. The chamber
tunnel defects facilitating bacterial microleakage. is filled with flowable composite/any other interim
Calcium hydroxide in due course of time (one to two restorative materials. MTA should be covered in wet
years) also becomes soft and allows leakage resulting conditions; dry MTA loses its cohesiveness and
in pulpal inflammation and necrosis. The concerned becomes hard to handle. Patient is recalled after one
tooth may show evidence of calcification or internal week. Patient is questioned about sensitivity and any
resorption; subsequently, root canal treatment is to be other discomfort. If comfortable, final restoration is
initiated. planned. In case discomfort persists, keep the patient
Calcium hydroxide has been used in various forms, under observation for 4–6 weeks. If still not comfortable,
viz. powder alone, paste form or commercially available root canal treatment is initiated.
calcium hydroxide. Bridge formed under MTA is tubular, thicker and
Powder alone is found to be highly irritating. Also continuous than that formed under calcium hydroxide.
prolonged exposure to atmosphere leads to the Pulp exhibits very less inflammation. MTA resists
formation of calcium carbonate, which forms an microleakage, even in presence of blood.
ineffective capping material (upper portion of the
Properties
powder in a jar should be discarded before use).
• Setting time: sets within 24 hours
Calcium hydroxide paste is applied in a thickness of
• Compressive strength: 70 MPa after one day
1.0 mm. Antibiotics should not be incorporated since
high degree of alkalinity of calcium hydroxide destroys/ • pH of the set MTA: 11–13 after setting
severely decreases the efficiency of antibiotics. • Biocompatible and nonmutagenic
• Antibacterial effect is similar to calcium hydroxide.
Disadvantages
• No curative effect on inflammation. d. Bonding agents
• No anodyne effect. It is established that healing is directly related to
capacity of pulp capping agent to provide a biological
• Chronic inflammation may lead to necrosis, abscess.
seal against immediate and long-term microleakage.
• Internal resorption may occur. Adhesive bonding agents have been tried as pulp
• Sclerosis of root canals; subsequent root canal capping agent. They do provide immediate seal;
treatment would be difficult. however, when adhesive agents were compared with
• High alkalinity may lead to surface tissue necrosis. calcium hydroxide, they showed more pulp necrosis.

Table 25.3 Composition of three types of mineral trioxide aggregate (MTA)

Gray White Modified
• Tricalcium silicate All others except iron Three versions:
• Dicalcium silicate i. Free of aluminium oxide
• Tricalcium oxide ii. Percentage of calcium oxide was
• Tricalcium aluminate increased to have more alkalinity
• Bismuth oxide (radiopacifier) iii. Addition of 1% methylcellulose increases

25
• Traces of free crystalline silica, calcium compressive strength
oxide, magnesium oxide, potassium,
iron and sodium sulfate

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 Vital Pulp Therapy 449

Histological studies have shown persistent inflamma- phosphatase when applied to exposed pulp stimulated
tory reactions and hyaline alteration of extracellular the differentiation of other pulp cells into odontoblast,
matrix inhibiting complete pulpal repair or bridge subsequently stimulating dentin matrix formation. It
formation when bonding agents were used. Direct has been reported that heme oxygenase-1 (HO-1) might
bonding agents are not preferred as it can lead to play a cytoprotective role against proinflammatory
inflammatory reaction, delay in pulpal healing and cytokines and nitric oxide in human pulp cells.
failure of dentin bridge formation. Simvastatin improves the osteoblast function and
e. Resin-resorcinol suppresses osteoclast function, resulting in enhanced
bone dentin formation. It stimulates the function of
Resin-resorcinol has also been successfully tried as pulp
odontoblasts, thus leading to improved dentin forma-
capping material (details in Chapter 37).
tion.
f. Polycarboxylate cement The enzymes induce angiogenesis and increases
Polycarboxylate cement is well-tolerated by the pulp. neuronal cells, indicating the possible effectiveness in
Its adhesive character provides the requisite marginal pulp regeneration along with dentin regeneration. It
seal. Initially polyacrylic acid in polycarboxylate cement has an anti-inflammatory effect; considered as an active
irritates the pulp tissue, which may subside over the pulp capping material to accelerate reparative dentin
time. However, induction of calcific bridge has not been formation.
reported.
k. Stem cells
g. Cyanoacrylates Stem cells are a group of undifferentiated biological
Isobutyl cyanoacrylates have been used with varying cells, which are capable of self-renewal and multi-
success. lineage differentiation. Their potential to stimulate
h. Combination of antibiotic and corticosteroids tertiary dentin formation is effectively explored as pulp
capping material.
Combination of antibiotics and corticosteroids have also
been used. These effectively provide bactericidal effect, Dental pulp stem cells and Stem cells from Human
which may lead to partial bridge formation. The Exfoliated Deciduous Teeth (SHED) have been
narrowing of root canals has also been reported with identified having the capacity of self-renewal and multi
their use. The material is clinically not preferred. lineage differentiation.
The disadvantage of stem cells might be their
i. Growth factors rejection because of immunological reasons (stem cells
Growth factors regulate growth and development and are derived from embryos that are not patients own
also induce wound healing and tissue regeneration. and the patient body may reject these cells).
Various forms of growth factors have been used as
pulp capping agents to induce repair of pulp. l. Propolis
Bone Morphogenic Protein (BMP), belonging to Propolis is a natural biological derivative containing
β-transforming growth factor (TGF-β), is a potent flavonoids, phenolics, iron, zinc and other aromatic
modulator of tissue repair. Bone morphogenic proteins compounds. It is traditionally used as anti-inflammatory
plays a vital role in the differentiation of adult pulp and antibacterial agent.
cells into odontoblasts during pulpal healing. Propolis has great potential as pulp capping agent.
The differentiated odontoblasts lead to deposition It has been effectively used as an antioxidant, reducing
of osteodentin and tubular dentin. hypersensitivity. Propolis has shown comparable
Other growth factors, such as insulin like growth results with MTA and Dycal, as regard dentin bridge
factor-I, epidermal growth factor, insulin-like growth formation. It may exhibit mild to moderate inflamma-
factor II, platelet-derived growth factor have also been tion, which stimulates dentin bridge formation.
tried. Insulin like growth factor-I has shown dentin
m. Emdogain
bridge formation.
Emdogain is enamel matrix derivative secreted from
j. Enzymes Hertwig’s epithelial root sheath during porcine tooth
Enzymes, such as heme-oxygenase-I and simvastatin development. It is rich in amelogenin and amelin
are being tried as pulp capping agent because of
their potential to induce functional odontoblasts
and improved dentin formation. Earlier, alkaline
protein, capable of inducing reparative process. It
stimulates the regeneration of acellular cementum,
periodontal ligaments, and alveolar bone.
25

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 450 Essentials of Endodontics

Emdogain contains biomolecular proteins, which p. Dentin shavings

promote odontoblast differentiation and reparative The sterilized dentin shavings when placed on exposed
dentin formation. It has been established that emdogain pulp stimulate the formation of reparative dentin. Both
suppresses the inflammatory cytokine production and analogous and homologous dentin chips have been
contains β-TGF growth factor; create a favorable successfully tried as pulp capping agent; however,
environment for promoting wound healing in the pulp. creating and placing dentin shavings over the pulpal
Emdogain is used as an adjunct along with other site is clinically difficult.
pulp capping agents to achieve desired results. q. Tricalcium phosphate
Various investigators have reported that MTA Tricalcium phosphate, when implanted in bone
produced a better quality reparative hard tissue with stimulate new bone formation. It does induce dentin
the adjunctive use of emdogain as compared with bridge formation; however, severe initial inflammation
calcium hydroxide. may lead to necrosis of pulp. Practically, it has been
Emdogenic gel when applied directly to exposed replaced by MTA.
pulp without the use of other pulp capping agent could
not produce the requisite hard tissue barrier (Emdogain r. Laser
possess poor sealing ability). Lasers have shown promising results, especially in
pulpotomy. Lasers effectively excise the surface pulp
n. TheraCal LC tissue, create bacteria-free environment, stimulating
TheraCal LC is a light cured, resin modified calcium collagen production and fibroblast proliferation. CO2
silicate liner, mainly used in direct/indirect pulp laser and ND-YAG laser have been extensively used in
capping, as a protective base/liner under restorative direct/indirect pulp capping.
materials. Being radiopaque, the material can be easily Lasers induce secondary dentin formation. The
identified during routine radiographic examination. targeted tissues are sterilized, providing sustained
TheraCal LC contains tricalcium silicate particles in bactericidal effect. However, the use of Laser is
a hydrophilic monomer, providing significant calcium technique sensitive; high doses may damage the
release. Calcium release stimulates dentin bridge underlying pulp tissue.
formation. The alkaline pH promotes apatite formation.
s. Miscellaneous
The barrier provides insulation and is moisture
resistant. A few materials like endosequence, castor oil bean
cement, calcium enriched mixture (endodontic cement),
It is established that TheraCal LC displayed higher
Freeze dried bone matrix, etc. have also been tried as
calcium releasing ability and low solubility than MTA pulp capping materials, with varying success.
or Dycal. TheraCal LC can be cured to a depth of
Table 25.4 summarizes the advantages and dis-
1.7 mm, which stabilizes the material at the site of advantages of various pulp capping agents.
placement.
o. Biodentine 3. Pulp Curettage
Biodentine is bioactive cement, simulating dentin in its It is well-documented that pulp exposure due to caries
physical properties. A modified form of calcium silicate usually lead to pulp necrosis with passage of time.
cement, it is mainly used as dentin substitute During caries removal, carious dentin chips may be
reinforcing lost coronal and radicular dentin. inadvertently pushed into pulp tissue resulting in
inflammation, resorption and encapsulation of dentin
Biodentine has shown promising results as an
chips which after capping may show foreign body
alternative to calcium hydroxide. It is biocompatible
reaction. It is suggested to remove superficial layer of
with high strength; also exhibit excellent marginal
pulp tissue by enlargement of the exposure site. This
adaptability. Its strong antibacterial activity provides procedure is known as ‘Pulp curettage’. It is followed
effective results when placed over deep carious lesions. by control of hemorrhage, placement of pulp capping
It has also been used as retrograde filling materials, pulp material and sealing the cavity as in direct pulp capping.
capping agent, in internal/external resorption and also
in apexification procedures. Advantages
It has been established that biodentine induces secon- • Preserves cell rich zone due to minimal excision;
dary dentin formation by stimulating odontoblastic cell chances of better healing.

25 differentiation. Biocompatibility and capability of

providing bacteria-free seal make Biodentine a material
of choice in pulp capping/pulpotomy procedures.
• Physiologic apposition of dentin is maintained.
• Natural color/translucency of tooth is maintained.
• Less chances of root canal obliteration.

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 Vital Pulp Therapy 451

Table 25.4 Pulp capping agents: Advantages and disadvantages

Pulp capping agent Advantages Disadvantages
Zinc oxide eugenol • Reduces inflammation • Lack of calcific bridge formation
• Act as obtundant • Eugenol released might be cytotoxic
Calcium hydroxide • Accepted pulp capping material • Highly soluble in oral fluids (potential of
• Antibacterial (high alkalinity) dissolution over time)
• Induction of mineralization (calcific bridge • Extensive dentin bridge formation
formation) • Lack of adhesion
• Low cytotoxicity • Acid etching may degrade layer of calcium
hydroxide
Mineral Trioxide Aggregate (MTA) • Less pulpal inflammation • Poor handling characteristics
• Hard tissue barrier formation is better than • Long setting time
calcium hydroxide • Grey MTA may cause tooth discoloration
• Antibacterial • High solubility
• Radiopaque
• Releases bioactive dentin matrix proteins
• Biocompatible
Bonding agents • Provide adhesion to hard tissues • Absence of calcific bridge formation
• Provide effective seal against microleakage • May lead to chronic inflammatory pulpal
response
• Potential of toxicity
Resin-resorcinol • Excellent sealing ability • Calcific bridge formation is natural, may be
due to bacteria-free seal
Polycarboxylate cement • Chemically bond to tooth structure • Do not stimulate calcific bridge formation
Isobutyl cyanoacrylate • Reduces pulp inflammation • Dentin bridge formation is not satisfactory
Corticosteroids and antibiotics • Reduces pulp inflammation • Should not be used in patients at risk from
• Combination may lead to reparative dentin bacteremia
bridge
Growth factors [Insulin like growth • Formation of osteodentin and tubular dentin • Fail to stimulate reparative dentin in inflamed
factor 1, Bone Morphogenic • Superior to calcium hydroxide as regard pulp
Protein (BMP)] mineralization inducing properties (formation • Technique sensitive (appropriate dose
of more homogeneous reparative dentin) required for positive results)
• Possibility of immunological problems
• All growth factors may not induce reparative
dentin formation
Enzymes (alkaline phosphatase, • Anti-inflammatory action • May lead to pulp tissue damage
heme-oxygenase 1, simvastatin) • Promote angiogenesis • Sensitive to appropriate concentration when
• Improve the function of odontoblasts; lead applied directly to pulp tissue
to superior dentin formation
Stem cells (pulp and other dental • Regeneration of dentin-pulp complex • Technique sensitive
origins) • Still under investigations
Propolis • Superior bridge formation (stimulate • May exhibit mild/ moderate inflammation
reparative dentin formation) after two to four weeks
• Reduces pulp inflammation and
degeneration
• Antioxidant, antibacterial, antifungal,
antiviral and anti-inflammatory properties
Emdogain • Induce odontoblast differentiation and • Emdogain gel when applied on exposed
reparative dentin formation pulps without the adjunctive use of a pulp-
• Suppresses the inflammatory cytokine capping material was ineffective in producing
production a hard tissue barrier (effective only as an
• Create a favorable environment for adjunct)
promoting pulp healing

25
• Amount of hard tissue formed with Emdogain
was twice as compared to calcium hydroxide
(Contd…)

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 452 Essentials of Endodontics

Table 25.4 Pulp capping agents: Advantages and disadvantages (Contd.)

Pulp capping agent Advantages Disadvantages
TheraCal LC • Stimulate regeneration of dentin-pulp • Opaque and ‘whitish’ color may show through
complex composite/ceramic materials affecting
• Bond to deep moist dentin esthetics
• Minimum solubility (solubility lower than MTA
and Dycal)
• Radiopaque
• Display higher calcium releasing ability
Biodentine • Biocompatible • Initially successful; long-term evaluation is
• Good antimicrobial activity not documented
• Stimulate tertiary dentin formation
• Less soluble
• Produces bacteria-free seal comparable to
calcium hydroxide
• Less setting time and good handling
characteristics
Dentin shavings • Induce secondary dentin deposition • Placing and creating dentin shavings is difficult
Tricalcium phosphate • Significant absence of pulp inflammation • Not much documented
• Good physical properties • Clinically difficult
• Induce calcific bridge formation
Lasers • Stimulate secondary dentin formation • May cause thermal damage to pulp
• Effective sterilization of targeted tissue • Technique sensitive
• Bactericidal • Secondary dentin formation is natural under
sterile environment
Miscellaneous (castor oil bean • Antibacterial • Bioinert rather than bioactive
cement) • Less cytotoxic • Not much documented
• Promote tissue healing
• Induce calcific barrier

4. Partial Pulpotomy Partial pulpotomy for carious exposures (Fig. 25.3a to d)

Partial pulpotomy is the removal of only outer layer of Procedure
damaged and hyperemic tissues in exposed pulps. (If • The inflamed pulp tissue beneath an exposure is
2.0–3.0 mm of pulp is removed, it is called ‘partial removed to a depth of 1.0 to 3.0 mm or deeper to
pulpotomy’). reach healthy pulp tissue.
Rationale • Pulpal bleeding is controlled by a bactericidal agent,
The rationale of partial pulpotomy is that following such as sodium hypochlorite.
surgical amputation of the affected or infected pulp • Site is covered with calcium hydroxide or MTA.
tissue at the exposure site, the remaining tissue is • Calcium hydroxide has been demonstrated to have
capable of healing. long-term success; MTA has shown more predictable
Indications dentin bridging and pulp health.
• A small and recent pulpal exposure in a noncarious Partial pulpotomy for traumatic exposures (Cvek
primary teeth. pulpotomy) (Fig. 25.4a to e)
• A very young tooth with a wide-open apex and very Procedure
thin root dentin walls.
• The procedure is similar to partial pulpotomy for
• Only if sufficient tooth structure is present to allow
carious exposures. In case of MTA, white, rather than
adequate restoration.
gray, is recommended, especially in anterior teeth
Contraindication to decrease the chance of discoloration (although
• If the exposure is very large (oral contaminants may both the versions have shown similar properties).
cause extensive infection or inflammation beyond • Tooth is sealed with an appropriate restorative
material to prevent microleakage.
25 2.0 to 3.0 mm of the exposure)
• When more than two weeks have passed between
injury and treatment time.
• If hemostasis is not achieved, cervical pulpotomy
should be performed.

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 Vital Pulp Therapy 453

Fig. 25.3 Partial pulpotomy for caries exposure: (a) Pulp exposure (more than 0.5 mm); (b) Partial removal of coronal
pulp; (c) Placement of calcium hydroxide; (d) Tooth restored

Fig. 25.4 Partial pulpotomy for traumatic exposure: (a) Fractured crown with pulp exposure (more than 0.5 mm);
(b) Partial removal of coronal pulp; (c) Placement of calcium hydroxide over remaining pulp; (d) Formation of reparative
dentin; (e) Tooth restored

Advantages of partial pulpotomy • It is advantageous over complete pulpotomy in the

preservation of cell-rich coronal pulp tissue.
• Procedure is quick and easy to perform.
• Maintains the natural tooth color and preserves the
tooth structure for better retention of restoration.
• Allow continuation of normal development of the tooth,
including further root development and maturation.
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 454 Essentials of Endodontics

The patient should be evaluated periodically for 2–4 • Marked constriction of pulp chamber as evident
years to determine outcome of the treatment. Although radiographically.
histologic success cannot be determined, clinical success • Teeth with symptoms of irreversible pulpitis.
is judged by the absence of clinical/radiographic signs • Pulp bleeds excessively after caries removal, which
of pathology and evidence of continued root develop- could not be controlled early.
ment in teeth with incompletely formed roots. The
remaining pulp should continue to be vital after partial Technique
pulpotomy. • Anesthetize the tooth.
• Isolate the tooth. If part of the tooth is fractured, a
5. Pulpotomy metal band is applied, which facilitates isolation.
Pulpotomy procedure implies surgical removal of • Carious tooth structure is removed with an appro-
partly/completely inflamed coronal pulp and priate, sterilized bur in a high speed handpiece and
protecting the radicular pulp with a suitable material air water coolant so that a straight line access is gained
to retain its vitality. It is followed by filling the coronal to the pulp chamber. In posterior teeth, approach is
chamber with a suitable base and restoring the tooth gained through occlusal surface and in anterior teeth,
with a material that seals the tooth from microleakage. it is gained from the site of trauma or palatal/lingual
Pulp inflammation results in local tissue necrosis and surface in intact teeth. Overheating should be avoided
microabscess formation. The local destruction releases because it can lead to damage to radicular pulp due
more chemical mediators and results in progress of to decreased circulation because of anesthesia.
inflammation. Healing depends on radicular pulp only. • Roof of the pulp chamber is removed with an
There is no physiological apposition of dentin in appropriate sized round bur. Shelf of dentin around
cervical area. So, the tooth is prone to fracture, and may the periphery of roof of coronal chamber is removed
discolor over time. Lack of coronal pulp does not to create funnel-shaped access.
provide reliable results with vitality tests. Root canal • Pulp is removed from coronal pulp chamber with a
obliteration may occur. sharp endodontic excavator or periodontal curette
(Fig. 25.5a and b). Twisting of pulp tissue is avoided.
Objectives In anterior teeth, since floor of the pulp chamber is
• Infected/inflamed area of pulp is removed leaving continuous, the incisal pulp is severed with an end-
vital, uninfected pulp tissue in root canal. cutting bur in a high speed handpiece with air-water
• Apexogenesis in immature teeth. coolant. Any strands of pulp tissue extending
• Pain relief in teeth with irreversible pulpitis. (Carried coronally from the pulp periphery are removed,
out as an emergency procedure). otherwise they may become necrotic and jeopardize
the outcome of the treatment.
Indications • Achieving hemostasis:
• Teeth with incomplete apical development: Hemostasis is achieved by one of the following way/
Pulpotomy keeps apical portion of the pulp vital to material:
allow normal root development and closure when – Direct pressure at the exposure site with a cotton
routine endodontic therapy can be instituted. pellet moistened with sterile saline
• As an emergency procedure before pulpectomy. – Iron sulfate (not used if adhesive restorations are
to be given)
• Attempted in selected cases of chronic hyperplastic
– Epinephrine
pulpitis in young patients.
– Sodium hypochlorite
• Mildly inflamed pulp with a very short history of
– MTAD
pain in a young patient.
– Aluminium chloride.
• Crown fracture exposing pulp.
(2.5–5.0% of sodium hypochlorite is used in routine. In
• Teeth posing difficulty in root canal treatment, e.g. addition to hemostasis, sodium hypochlorite allows for
sharp apical dilacerations or inaccessible molars. removal of dentin chips, chemical amputation of blood clot,
fibrin and disinfection of cavity interface. It has been
Contraindications
observed that hemostasis with sodium hypochlorite does
• Traumatized teeth with little clinical crown.
25 • Teeth to be used as bridge/partial denture abutment.
• Teeth involved in complex periodontal therapy.
not impair the biological repair. If pulpal hemostasis
cannot be obtained in 5–10 minutes, the diagnosis is
irreversible pulpitis and pulpectomy should be considered).

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 Vital Pulp Therapy 455

Fig. 25.5 Pulpotomy: (a) Pulp exposure (more than 1.0 mm); (b) Complete removal of coronal pulp; (c) Placement of
calcium hydroxide over remaining pulp; (d) Reparative dentin formation; (e) Tooth restored

• The materials used for pulpotomy are the same as Various materials have been used for pulpal wound
for pulp capping. Formocresol/glutaraldehyde is dressing; however, the use of calcium hydroxide has
usually preferred for pulpotomy in primary teeth been shown to be the most predictable with regard to
and avoided in permanent teeth. However, it may long-term clinical success. Mineral Trioxide Aggregate
be used as an emergency measure to relieve pain in has also shown favorable clinical and histological results
permanent teeth. It sanitizes and fixes pulp tissue. in pulp capping, apexogenesis and apexification cases.
No calcific bridge is formed. Apical third of the pulp
may retain its vitality for an extended period of time. Indications
• Calcium hydroxide/any suitable material is placed • In immature teeth when part of the pulp tissue
over the remaining pulp (Fig. 25.5c). remains vital and uninflamed, as in carious
• The tooth is restored after the signs of reparative exposures.
dentin are evident (Fig. 25.5d and e). • In some trauma cases in which pulp exposure
occurred.
Disadvantages
• Causticity Goals
• Carcinogenicity/mutagenicity • Sustaining a viable Hertwig’s sheath, thus allowing
• Fixes even healthy radicular pulp tissue continued development of root length for a more
• Internal resorption favorable crown-to-root ratio.
• Calcific metamorphosis. • Maintaining pulpal vitality, thus allowing the
remaining odontoblasts to lay down dentin,
6. Apexogenesis (Root Formation) producing a thicker root and decreasing the chance
Apexogenesis is a histological term used to describe of root fracture.
the continued physiologic development and formation • Promoting root-end closure, thus creating a natural
of the root’s apex. It can be regarded as a very deep apical constriction for root canal filling.
pulpotomy. Harrison and Raskun (1985) termed apical • Generating a dentinal bridge at the site of the
closure with continued root development as apexo- pulpotomy.
genesis with vital pulp.
Procedure
Apexogenesis is defined as ‘a vital pulp therapy
procedure performed to encourage continued physiological
development and formation of the root end’.
It involves removal of the inflamed coronal pulp and
the placement of calcium hydroxide on the remaining
25

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 456 Essentials of Endodontics

Fig. 25.6 Apexogenesis with calcium hydroxide: (a) Pulp exposure (more than 1.0 mm); (b) Removal of pulp, except in
apical third area, (c) Placement of calcium hydroxide over remaining pulp; (d) Obturation with gutta-percha over calcium
hydroxide; (e) Tooth restored after closure of apex

healthy pulp tissue. However, the depth to which the APEXIFICATION (ROOT END CLOSURE)
tissue is removed should be determined by clinical Endodontic management of the pulpless permanent
judgment. Calcium hydroxide is placed over vital pulp teeth with a wide open blunderbuss apex has always
stump after hemostasis. For deeper amputation calcium been challenging. Endodontic treatment of young
hydroxide powder packed in an amalgam carrier is permanent teeth may also present difficulties due to
carried at the site (Fig. 25.6a to e). Radiographic and the incomplete root development and associated open
clinical follow-up is mandatory. apices. Such teeth usually have thin, fragile walls,
The total time for achievement of positive result of making it difficult to clean and subsequently attain the
the apexogenesis ranges between one and two years required apical seal. To achieve the apical barrier for
depending on the degree of tooth development at the effective endodontic treatment, apexification procedure
time of the procedure. The patient should be recalled is undertaken, facilitating formation of calcific barrier
in a root with open apex or continued apical develop-
at 3-monthly intervals in order to determine the vitality
ment of an incomplete root with necrotic pulp.
of the pulp and the extent of apical maturation. If it is
Apexification is defined as ‘a procedure of inducing
determined that the pulp has become irreversibly
apical closure through the formation of mineralized tissue in
inflamed or necrotic, or if internal resorption is evident,
the apical pulp region of a nonvital tooth with an incompletely
the pulp should be extirpated and apexification therapy
formed root and an open apex’.
initiated.
(Apexification is indicated in nonvital permanent
Controversy exists as to whether further endodontic teeth with incomplete formed roots; whereas, Apexo-
intervention should be carried out following the comple- genesis is carried out in vital teeth).
tion of root development. Since, it is not possible to
determine the pulp vitality or the health of the remaining Aims
pulp tissue, it has been advocated that once root • Induce the formation of hard tissue barrier across
development appears to be completed, the tooth should the open apex, allowing proper condensation of
be re-entered and root canal therapy performed. obturating material in the root canal spaces.
However, it is emphasized that initiation of endodontic • The hard tissue barrier, so formed, will not allow

25 treatment prior to development of root resorption, canal

obliteration and the development of apical periodontitis
will lead to long-term success.
the irrigant/filling material to extrude out of the
apical foramen.
• The procedure should not lead to periapical pathology.

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 Vital Pulp Therapy 457

Procedure distilled water, metacresol acetate, cresanol (CPMC +

Many techniques have been advocated to manage open metacresol acetate), methylcellulose base, normal saline
apex in nonvital teeth. The techniques managing the solution, Ringer’s solution and Anesthetic solution. The
open apex in nonvital teeth are mostly confined to fill addition of barium sulfate enhances its radiopacity.
conventional paste (calcium hydroxide and The concerned tooth is prepared and disinfected in
combination) periodically, till calcific barrier is formed routine. Sodium hypochlorite and chlorhexidine
at the apex. This type of procedure is carried out in solutions are preferred as irrigants. The clean canal is
multivisits (may take 9 to 18 months for calcific bridge filled apically with calcium hydroxide paste, followed
formation) (Fig. 25.7a to e). by sealing the coronal end with interim filling materials.
The procedure was modified over the years and Various combinations of calcium hydroxide, as
carried out in one visit. The rationale is to establish an described above, have been used as apical seal material;
apical stop that would enable the root canal to be filled calcium hydroxide and methylcellulose (pulpdent),
immediately. A number of materials have been because of better consistency and less solubility, is
proposed, including tricalcium phosphate, calcium preferred over other materials.
hydroxide, freeze dried bone and mineral trioxide The calcium hydroxide ‘dressing’ is to be repeated
aggregate in one-visit apexification. The materials every six to eight weeks for better results (controversy
provide scaffolding for the formation of hard tissue and exist as regard re-filling of calcium hydroxide and after
the potential of a better biological seal. how long a time; a few authors prefer no re-filling,
Various materials have been tried for apexification; whereas others prefer changing calcium hydroxide
the important ones are: every month, after 3 and 6 months).
a. Calcium hydroxide It is hypothesized that the high pH of calcium
b. Triple antibiotic paste hydroxide is an important factor in its ability to induce
c. Mineral trioxide aggregate (MTA). hard tissue formation. The antimicrobial activity is
related to the release of hydroxyl ions, which are highly
a. Calcium Hydroxide oxidant and show extreme reactivity. These ions
Calcium hydroxide is used with different medium such damage the bacterial cytoplasmic membrane, protein
as, camphorated paramonochlorophenol (CPMC), denaturation and the bacterial DNA.

Fig. 25.7 Apexification with calcium hydroxide: (a) Open apex with periapical rarefaction; (b) Removal of necrotic pulp;
(c) Preparation of root canal; (d) Placement of calcium hydroxide dressing; (e) Tooth restored after formation of calcific
barrier
25

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 458 Essentials of Endodontics

However, if there is remaining vital pulp tissue in both bactericidal (metronidazole and ciprofloxacin) and
the canal, the direct contact of calcium hydroxide paste bacteriostatic (minocycline) antibiotics]. Additionally,
with the tissue will induce the formation of a layer of minocycline causes tooth discoloration (minocycline
calcific tissue, which may occupy the pulp space; can be replaced with cephalexin to avoid discoloration).
thereby preventing the pulp tissue to regenerate into Triple antibiotic and double antibiotic pastes have been
that space. Another concern is that calcium hydroxide successfully used in apexification procedures.
may damage the Hertwig’s epithelial root sheath
c. Mineral Trioxide Aggregate (MTA)
and thereby losing its ability to induce the nearby
undifferentiated cells to become odontoblasts. Mineral trioxide aggregate (MTA) has shown promising
results when used to create apical barrier in open apex
Limitations teeth. In nonvital open-apex teeth with short root
• Long span of the treatment lengths, the root can completely be filled with MTA
• Procedure requires multivisits; clinical protocol to (Fig. 25.8a to e).
be followed in each visit The root canal system should be thoroughly cleaned
• Risk of re-infection; periapical exudate may dissolve and disinfected using sodium hypochlorite irrigation.
calcium hydroxide. A calcium hydroxide paste is placed in the root canal
for at least one week to effectively eradicate the residual
b. Triple Antibiotic Paste microorganisms. Thereafter, calcium hydroxide paste
The bactericidal efficacy of triple antibiotic paste is rinsed out and the root canal is irrigated with 5.0%
(metronidazole, ciprofloxacin, minocycline) has been sodium hypochlorite and 17% EDTA and dried with
successfully tested against microbes from carious sterile paper points. A thick mix of MTA is prepared
dentin and infected pulp. It is established that triple by mixing MTA powder with sterile water and is
antibiotic paste is sufficiently potent to eradicate the carried to the canal with a specific carrier. MTA is
bacteria from the root canal systems. Intracanal condensed to the apical end of the canal with an appro-
medication with triple antibiotic paste for four weeks priate plugger. A 3.0–4.0 mm apical plug is created and
is an effective approach to manage nonvital open-apex its density, position and extension are checked
teeth promoting continuing root development. radiographically. If an ideal plug is not created in the
The main concern of using the antibiotic paste is that first attempt, MTA should be rinsed out with sterile
it may lead to bacterial resistance [The paste contains water and the procedure should be repeated. The

25 Fig. 25.8 Apexification with MTA: (a) Open apex with periapical rarefaction; (b) Preparation of root canal; (c) Placement
of MTA at the apical end; (d) Formation of calcific barrier at apex; (e) Tooth restored

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 Vital Pulp Therapy 459

coronal end is sealed with appropriate interim material, barrier has also been successfully tried (PRF is an
such as Cavit. After two weeks, if the tooth is asympto- immune platelet rich concentrate, when placed as
matic, the canal is evaluated for any pathological matrix, promote healing and repair; also control
exudates. If no pathological feature, the coronal cavity adequate filling of MTA).
is filled with glass-ionomer cement. The tooth should The necessity of the use of medicament for induction
be followed up periodically to observe the formation of apical barrier formation is questioned. Nygaard-
of calcific barrier at the root apex. Gutta-percha is used Ostby hypothesized that laceration of the periapical
to fill the remaining canal space. If the canal walls are tissues until bleeding occurred might produce new vital
thin, the canal space can be completely filled with MTA vascularized tissue in the canal. He suggested that this
to strengthen the tooth against fracture. Adverse post- treatment may result in further development of the
treatment signs or symptoms, such as sensitivity, pain, apex. Infected necrotic pulp tissue induces strong
or swelling should not be evident. There should be no inflammatory reactions in the periapical tissues.
radiographic evidence of external root resorption, root Therefore, its removal should create an environment
fracture, or breakdown of periradicular supporting conducive to apical closure without use of a medication.
tissues during or following therapy. The tooth should It was believed that instrumentation may in fact hamper
continue to erupt, and the alveolus should continue to root development.
grow in conjunction with the adjacent teeth. Apexifica- Hemorrhage was induced by an endodontic explorer
tion with MTA in maxillary central incisor is depicted penetrating slightly into the periapical tissue allowing
in Fig. 25.9a and b. the blood clot to form in the canal and stopped at a
MTA is biocompatible and has good sealing ability. level 3.0 mm apical to cementoenamel junction. Mineral
Coronal sealing with glass-ionomer further provide the trioxide aggregate was then placed over the blood clot.
requisite bacteria-free seal. An internal matrix created Calcium hydroxide is not preferred as intracanal
by platelet rich fibrin (PRF) along with MTA as apical dressing after blood clot. The calcific tissue initiated
by calcium hydroxide may prevent pulpal tissue from
regeneration. Secondly, presence of calcium hydroxide
can damage Hertwig’s epithelial root sheath; also do
not facilitate undifferentiated viable cells to differentiate
into odontoblasts. It was considered that the blood clot
acts as a scaffold and source of growth factors to
facilitate the repair and regeneration of tissues into the
canal; however, there is lack of histological evidence
confirming blood clot for the formation of repaired
tissues. This is the basis of regenerative endodontics,
described in detail in Chapter 38.
Because of the thin dentinal walls, the incidence of
Fig. 25.9a Working length determination (open apex) root fractures in teeth after apexification is high. Restora-
tive efforts should be directed towards strengthening
the immature root. Newer dentin bonding techniques
have found to significantly increase the resistance to
fracture of these teeth, as good as of intact teeth.
A technique is tried, in which the access is restored
with a composite restoration and a clear curing post is
inserted into the soft composite and cured. The post is
then removed leaving a patent channel for calcium
hydroxide replacement and subsequent obturation.

Mechanism of Continued Root Formation

Vitality of Hertwig’s epithelial root sheath (HERS) is
important for continued formation of the apical portion

Fig. 25.9b Apexification with MTA

of the root. Mesenchymal cells in the periapical region
and the organizing influence of HERS may differentiate
into formative cells which form the apex.
25

t.me/Dr_Mouayyad_AlbtousH
 460 Essentials of Endodontics

There are four clinical possibilities in apexification: assessment of various vital pulp-therapy materials. J. Endod.:
• Definite apical closure with minimal recession of the 2003; 29:324–333.
root canal. 12. Duncan HF, Nair PNR and Pittford TR. Vital pulp treatment:
a review. Endod. Practice: 2008; 2:247–258.
• No reduction in the space of the root canal; canal
may be shaped like a blunderbuss. 13. European Society of Endodontology. Quality guidelines for
endodontic treatment: Consensus report of the European
• Radiographically, a calcified barrier located Society of Endodontology. Int. Endod. J.: 2006; 39:921–930.
coronally to the root apex.
14. Kumar A, Yadav A and Shetty N. One-step apexification using
• Evidence of pathology in the periapex or in the root platelet rich fibrin matrix and mineral trioxide aggregate apical
canal (sign of failure of apexification). barrier. Ind. J. Dent. Resch.: 2014; 25:809–812.
The calcified apical barrier mainly consists of 15. Lim KC and Kirk EEJ. Direct pulp capping: a review. Endod
cementum along walls of root canal along with Dental Traumatol.: 1987, 3; 213–219.
dentinal/bony tissue. 16. Mjor IA, Dahl E and Cox CF. Healing of pulp exposure: an
Hertwig’s epithelial root sheath may and may not ultrastructural study. J. Oral Pathol. Med.: 1991; 20:496–501.
be present. The calcified tissue is not exactly dentin or 17. Modina KC, Casas-Apayco LC Atta MT, Costa CA, Hebling J,
cementum; however, it simulates characteristics of Sipert CR, Navarro MF and Santos CF. Cytotoxicity and
dentin, cementum and bone. biocompatibility of direct and indirect pulp capping materials.
J Appl Oral Sci.: 2009, 17; 544–554.
BIBLIOGRAPHY 18. Nosrat A and Asgray S. Apexogenesis of a symptomatic molar
with calcium enriched mixture. Int. Endod. J.: 2010; 43:
1. Abu-Tahun I and Torabinejad M. Management of teeth with 940–944.
vital pulps and open apices. Endod. Topics: 2012; 23:79–104. 19. Olivi G, Genovese MD, Maturo P and Docimo R. Pulp
2. Aguilar P and Linsuwanont P. Vital pulp therapy in vital capping: Advantages of using laser technology. Eur. Arch.
permanent teeth with cariously exposed pulp: A systematic Pediat. Dent.: 2007; 8:89–95.
review. J. Endod.: 2011; 37:581–587. 20. Olsson H, Petersson K and Rohlin M. Formation of a hard
3. Albuquerque MTP, Nagata JY, de Jesus SA and Zaia AA. Pulp tissue barrier after pulp capping in humans—a systematic
revascularization: an alternative treatment to the apexification review. Int. Endod. J.: 2006; 39:429–442.
of immature teeth. Rev Gauch Odontol.: 2014; 62:401–410. 21. Paulindraraj S, Venkatesan R, Suprakasam S and Christopher
4. Asgray S and Ehsani S. Permanent molar pulpotomy with a A. Apexification – Then and Now: A review. Int. J. Dent.
new endodontic cement: a case series. J. Conserv. Dent.: Med. Res.: 2015; 1:193–196.
2009; 12:31–36. 22. Roberts HW, Toth JM, Berzins DW and Charlton DG. Mineral
5. Bergenholtz, G. Factors in pulpal repair after oral exposure. trioxide aggregate material use in endodontic treatment: A
Adv. Dent. Res. 2001, 15, 84. Waterhouse, P.J. “New age” review of literature. Dent. Mater.: 2008; 24:149–164.
pulp therapy: Personal thoughts on a hot debate. Pediat. Dent. 23. Shabahang S. Treatment options: Apexogenesis and
2008; 30, 247–252. Apexification. J Endod.: 2013, 39; 526–529.
6. Bergenholtz G, Axelsson S, Davidson T, Frisk F, Hakeberg 24. Sikri V and Sikri P. Direct pulp capping with resorcinol: a
M, Kvist T, Norlund A, Petersson A, and Portenier I. Treatment clinical and histological evaluation. JCD: 1998; 1:90.
of pulps in teeth affected by deep caries—a systematic review 25. Siqueira Jr JF and Lopes HP. Mechanisms of antimicrobial
of the literature. Singapore Dent. J.: 2013; 34:1–12. activity of calcium hydraulic: a critical review. Int. Endod. J.:
7. Beeley JA, Yip HK and Stevenson AG. Chemochemical caries 1999; 32:361–369.
removal: a review of the techniques and latest developments. 26. Stabholz A, Sahar-Helft S and Moshonov J. Lasers in
Br. Dent. J.: 2000; 188:427–430. Endodontics. Dent. Cl. North Am.: 2004; 48:809–832.
8. Bindsley PH and Lvschall H. Treatment outcome of vital pulp 27. Swift EJ, Trope M and Ritter AV. Vital pulp therapy for the
treatment. Endod. Topics: 2002; 2:24–34. mature teeth – can it work? Endod. Topics: 2003; 5:49–56.
9. Camilleri J, Montesin FE, Brady K, Curtis RU, Sweeney R and 28. Tziafas D, Smith A and Lesot H. Designing new treatment
Pittford TR. The constitution of mineral trioxide aggregate. strategies in vital pulp therapy. J. Dent.: 2000; 28:77–92.
Dent. Mater.: 2005; 21:297–303. 29. Quershi A, Soujanya E and Nandkumar. Recent advances in
10. Desouza CA, Hebling J and Hanks CT. Current status of pulp pulp capping materials: An overview, J Clinical Diag. Res.:
capping with dentin adhesive systems: a review. Dent. Mater.: 2014, 8:316–321.
2000; 16:188–197. 30. Zhang W and Yelick PC. Vital pulp therapy: current progress
11. Dominguez MS, Witherspoon BE, Gutman JL and Operman of dental pulp regeneration and Re-vascularization. Int. J.
LA. Histological and scanning electron microscopy Dent.: 2010; 1 (Online).

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t.me/Dr_Mouayyad_AlbtousH
 Chapter
26
Traumatic Dental Injuries
and Management

Traumatic injury refers to physical injuries of sudden Horizontal root fracture occurs mainly in the anterior
onset and severity which require immediate attention. region of maxilla, usually owing to the frontal impact.
The injury may lead to systemic shock called ‘shock It is usually observed in fully erupted teeth with
trauma’ and may require medical interventions. complete root formation. It occurs more frequently in
Traumatic dental injuries are often unanticipated the middle third of the root and rarely in the apical
events mainly affecting children and adolescents. third. The prognosis is poor if the fracture level is at
Traumatic injury is one of the common cause of damage the coronal third.
to tooth and the supporting structures. Such injuries
involve perioral soft tissues, teeth and the supporting Etiology
tissues. The management involves overall treatment of i. Accidental fall; may be at home/school or road
all the affected tissues. These injuries are to be attended traffic accidents.
immediately to avoid serious consequences. The careful ii. Domestic violence due to child abuse or physical
examination of the clinical findings and immediately trauma.
planned treatment modality can favor a successful iii. Collision during sports activities.
outcome. Dr Anderson, a pioneer in dental traumato-
iv. Bruxism and age related attrition.
logy, has contributed a lot as regards diagnosis, etiology
and incidence of dental injuries. v. Bacteriological (extensive caries lesion).
vi. Iatrogenic
Incidence • Extensive tooth preparation for restorations
Maxillary incisors are more frequently involved in • Tooth structure loss due to endodontic procedures
traumatic injuries as compared to mandibular incisors.
Males sustain injuries two or three times more as Traumatic Dental Injuries: Types and Nomenclature
compared to females. It is documented that children in The luxation injuries are:
the age of 8–12 years are more prone to dental injuries.
• Avulsion: The complete displacement of the tooth out
The protrusion of the maxillary incisors is one of the
of its socket.
predisposing factor in these traumatic injuries. Children
with Angle’s class II Div. I malocclusion are three times • Concussion: An injury to the tooth-supporting
more prone to traumatic injuries. structures without any displacement; but with pain
to percussion.
Traumatic injuries may involve only crown or only
root or both crown and the root. Injuries to the tooth • Intrusion: Displacement of the tooth into the alveolar
structure depend on the severity of the blow; i.e. mild, bone, characterized by crushing of alveolar socket.
moderate or severe. Mild impact usually leads to • Extrusion: Partial displacement of the tooth out of
concussion or luxation without fracture of the tooth. its alveolar socket, characterized by separation of the
Moderate impact lead to crown fracture with or without periodontal ligament. Apart from axial displacement,
pulpal involvement or only intrusive luxation; the tooth will usually have an element of protrusion.
however, crown-root fracture or displacement of the The alveolar socket bone remains intact.
tooth is the common finding with severe impact. • Subluxation: An injury to the tooth-supporting
Root fractures in permanent teeth are less frequent, structures, but without displacement of the tooth.
comprising 0.5 to 5% of all traumatic injuries. Bleeding from the gingival sulcus in early case.

461

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 462 Essentials of Endodontics

• Lateral luxation: Displacement of the tooth out of its of international classification of diseases to dentistry
socket other than axially, characterized by separation and stomatology. The classification is applicable to injuries
of the periodontal ligament. Fracture of either the to the teeth and supporting structure and can be applied
labial or the palatal/lingual alveolar bone (one side). to both primary and permanent dentition. The classifica-
If both sides of the alveolar socket have been fractured, tions suggested by different authors are as follows:
the injury should be classified as an alveolar fracture.
Author (Year) Classification
The injuries affecting tooth and/or bone are:
Sweet (1955) Classified fractures of anterior teeth into eight
• Enamel fracture: A fracture confined to the enamel classes
with loss of tooth structure.
Rabinowitch Classified injuries of the primary teeth into six
• Enamel infraction: An incomplete fracture or crack in (1956) types
the enamel without a loss of tooth structure. Ellis (1961) Classified anterior teeth fracture into six
• Incomplete tooth fracture: A demonstrable fracture groups
with no visible separation of the segment along the Garcia-Godoy Classified traumatic injuries of primary and
plane of fracture. (1968) permanent teeth into nine classes
• Fissured fracture: A crack in the crown of the tooth. Ellis and Davey Modified Ellis classification and classified
• Root fracture: A fracture of root, may be horizontal (1970) anterior teeth fracture
or vertical Silvestri and Classified posterior teeth fractures into four
• Alveolar fracture: A fracture of the alveolar process, Singh (1970) types
involving the alveolar socket. Teeth with alveolar WHO (1978) Classified oral structures injuries using code
fractures are characterized by mobility of the alveolar numbers for both primary and permanent
teeth
process; several teeth move as a unit.
• Uncomplicated crown and root fracture: A fracture Andreasen Modified WHO classification by including
(1978) terms, uncomplicated/complicated crown-
through the enamel, dentin, and cementum which root fracture and concussion/ subluxation/
caused a loss of tooth structure; without pulp lateral luxation
involvement. Heithersay and Classified root fractures into five classes
• Uncomplicated crown fracture: A fracture through the Morile (1982)
enamel and dentin which caused a loss of tooth Pulver (1982) Combined the classifications of Ellis and
structure; without pulp involvement. Davey, Andreasen, Hargreaves and Craig,
• Complicated crown fracture: A fracture through enamel McDonald and Avery: classified traumatized
teeth into five classes
and dentin which caused a loss of tooth structure;
involving pulp. McDonald, Modified Ellis and Davey classification into
Avery and four classes
• Complicated crown and root fracture: A fracture through Lynah (1983)
the enamel, dentin, and cementum which caused a
Ulfohn (1985) Classified crown fractures into three classes
loss of tooth structure; involving pulp.
International Accepted WHO Classification of traumatic
• Cracked tooth syndrome: It refers to the incomplete classification dental injuries with codes
fracture of the vital tooth that involves the dentin of diseases in
and occasionally extends into the pulp. dentistry and
stomatology
The injuries affecting soft tissues/oral mucosa are: (1992)
• Abrasion: A superficial bleeding wound caused by the Feiglin (1995) Classified transverse root fractures into three
rubbing or scraping of tissues with an object or surface. zones
• Contusion: A bruise of the gingiva/oral mucosa Filippi, Tschan Classified tooth injuries using a new scoring
caused by a blunt object often associated with an Pohl, Berthold system
adjacent bone fracture. and Ebeleseder
(2000)
• Laceration: A wound in the gingiva or oral mucosa
Spinas and Classified crown fractures of teeth into four
caused by a penetrating sharp object.
Altana (2002) classes
Berman, Branco Classified dental injuries into hard injuries and
CLASSIFICATION and Cohen soft injuries

26 Many attempts have been made over the years to (2007)

classify dental injuries. The currently accepted system Loomba et al Classified tooth fractures based on treatment
is based on the World Health Organization’s application (2010) needs into four types

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 Traumatic Dental Injuries and Management 463

Classification by Ellis accompanied by comminution or fracture of the

Class 1: Simple fracture of crown involving little or no alveolar socket.
dentin 4. Extrusive luxation (N873.66): Partial displacement of
Class 2: Extensive fracture of the crown involving the tooth out of its socket.
considerable dentin but not the pulp 5. Lateral luxation (N873.66): Displacement of the tooth
Class 3: Extensive fracture of the crown involving in a direction other than axially. This is accompanied
considerable dentin and exposing the pulp by comminution or fracture of the alveolar socket.
Class 4: Traumatized teeth that become non-vital with 6. Ex-articulation complete avulsion (N873.68): Complete
or without loss of the crown structure displacement of the tooth out of its socket.
Class 5: Teeth lost as a result of trauma
C. Injuries to the Supporting Bone
Class 6: Fracture of the root with or without the loss of
crown structure 1. Comminution of the alveolar socket (Mandible N802.20,
Maxilla N802.40): Crushing and compression of the
Ellis and Davey modified the Ellis classification and
alveolar socket.
added two more classes:
2. Fracture of the alveolar socket wall (Mandible N802.20,
Class 7: Displacement of a tooth without fracture of the
Maxilla N802.40): A fracture contained to the facial
crown or root
or lingual socket wall.
Class 8: Fracture of crown en-masse and its replace-
3. Fracture of the alveolar process (Mandible N802.20,
ment
Maxilla N802.40): A fracture of the alveolar process
Hargreaves and Craig further modified Ellis and Davey
which may or may not involve the alveolar socket.
classification and added one more class:
4. Fracture of the mandible and maxilla (Mandible N802.21,
Class 9: Traumatic injuries to primary teeth
Maxilla N802.42): Fracture involving the base of the
mandible or maxilla. It may and may not involve
Classification by Andreasen
alveolar socket.
A. Injuries to Hard Dental Tissues and Pulp
D. Injuries to Gingiva or Oral Mucosa
1. Crown infraction (N873.60): An incomplete fracture
of the enamel without loss of the tooth substance. 1. Laceration of gingival or oral mucosa (N873.69)
2. Uncomplicated crown fracture (N873.61): A fracture 2. Contusion of gingiva or oral mucosa (N902.00)
contained to the enamel or involving enamel and 3. Abrasion of gingiva or oral mucosa (N910.00)
dentin but not exposing the pulp.
3. Complicated crown fracture (N873.62): A fracture Classification by Garcia Godoy (Fractures of
involving enamel and dentin and exposing the pulp. Primary Teeth)
4. Root fracture (N873.63): A fracture involving dentin, Class I: Enamel fracture
cementum and the pulp. Class II: Enamel and dentin fracture without pulp
5. Uncomplicated crown root fracture (N873.64): A fracture exposure
involving enamel, dentin and cementum but not Class III: Enamel and dentin fracture with pulp
involving the pulp. exposure
6. Complicated crown root fracture (N873.65): A fracture Class IV: Enamel, dentin and cementum fracture
involving enamel, dentin and cementum and Class V: Root fracture
exposing pulp. Class VI: Concussion
B. Injuries to the Periodontal Tissue Class VII: Luxation
1. Concussion (N873.66): An injury to the tooth Class VIII: Extrusion
supporting structures without abnormal loosening Class IX: Avulsion
or displacement of the tooth, but with marked
reaction to percussion. Classification by Filippi et al
2. Subluxation (N873.66): An injury to the tooth Filippi et al (2000) used a new scoring system to classify
supporting structures with abnormal loosening but tooth injuries.

26
without displacement of the tooth. The new scoring system designates the tissues
3. Intrusive luxation (N873.67): Displacement of the involved in trauma to anterior teeth, i.e. dental tissues
tooth into the alveolar bone. This injury is (enamel, dentin), endodontium (pulp), periodontium,

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 464 Essentials of Endodontics

alveolar bone and gingiva. Depending upon the Class D: Enamel dentin lesions involving the mesial or
severity of injury, each of five tissues is given a number distal angle/incisal or palatal surface and root
between 0 and 5 (Table 26.1). Assessment of the involvement.
complete tooth which also takes the form of number; When necrotic pulp is present, the letter 'h' is placed
the so called ‘score’ is made after diagnosing the after the main class.
individual tissues and allocating the corresponding
numbers. The lowest value is then multiplied by the Berman, Blanco and Cohen’s Classification
sum of the other four values. For example, a healthy Berman, Blanco and Cohen classified injuries to the
uninjured tooth, allotted five tissues the value five, is dentition into two main types:
thus given the maximum score of 100 and if one of the A. Hard tissue injuries: Involving the teeth, alveolar bone
tissues cannot be treated anymore, is given the value and other facial bones.
zero, then the tooth also may be considered as not worth B. Soft tissue injuries: Involving facial skin, lips, mucosa
saving and scores zero. (cheeks and periodontium), soft tissues of the hard/
A score of 80 signifies that the tissues are healthy; soft palate and tongue.
only pulp vitality could not be diagnosed with certainty.
A score of 60 means that the tissues are healthy but A. Hard Tissue Injuries
endodontic treatment was required. All scores under a. Crown fracture: Crown fracture includes:
60 signify failure or complication in any one of the i. Enamel infraction
tissues examined. ii. Uncomplicated crown fracture
iii. Complicated crown fracture
Spinas and Altana’s Classification b. Root fracture: There may be an injury of the tooth that
Spinas and Altana classified traumatic injuries into four does not directly affect the crown of the tooth, but
classes: rather causes a fracture through the root. This
Class A: Simple enamel lesion involving one proximal fracture may be vertical, horizontal or oblique in
angle or only incisal edge. relationship to the long axis of root.
i. Crown—root fracture
Class B: Enamel dentin lesions involving one proximal
ii. Intra-alveolar root fracture—the injury involves
angle or only the incisal edge; subclass B1: with
fracture of the root that is completely encased
pulp exposure.
within bone. The fracture may be horizontal or
Class C: Enamel dentin lesion involving the incisal edge more diagonal and typically divides the root into
and at least one-third of the crown; subclass two fragments—a coronal fragment and the apical
C1: with pulp exposure. fragment.

Table 26.1 Numerical allocation after diagnosis of individual tissues (Filippi et al 2000)
Score Hard (enamel Endodontium Periodontium Alveolar bone Gingiva
dentin) tissues (pulp)
5 Intact crown Intact endodontium Intact periodontium Intact alveolar bone Intact gingiva
(pulp not involved)
4 Enamel infraction, Exposure of dentin Concussion Contusion of marginal Contusion
fracture of root apex bone
3 Enamel-dentin Large pulp exposure • Subluxation Fracture of alveolar Rupture of papilla
fracture, intraalveolar internal contusion • Extrusion socket
root fracture (root fracture) • Lateral luxation
2 Crown root fracture Infection of pulp • Intrusion Fracture of alveolar Vertical laceration
(directly restorable) • Reimplantation with process
vital periodontium
1 Crown root fracture Endodontic complica- • Luxation and perio- Fracture and infection Infected laceration
(indirectly restorable) tion (e.g. internal root dontal infection
resorption)

26 0 Vertical fracture or
lost tooth
Endodontic periodontal Reimplantation with
lesion necrotic periodontium
Loss of alveolar socket Loss of gingiva

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 Traumatic Dental Injuries and Management 465

c. Luxation injuries: When a traumatic injury to a tooth Division 1: Fractures involving the cusp/cusps
causes its displacement from the socket, it is termed A. Fractures involving one cusp
as luxation injury; such as:
B. Fractures involving two cusps
i. Concussion
C. Fractures involving three cusps
ii. Subluxation
D. Fractures involving four or more cusps
iii. Lateral luxation
iv. Intrusion (intrusive luxation) Division 2: Fracture of crown en masse
v. Extrusive luxation Division 3: Fracture involving root or roots
vi. Avulsion
Type III: Fractures of teeth in the vertical or longitudinal
d. Alveolar injuries: There are several types of fractures plane
of bone tissues secondary to dental injuries.
Division 1: Incomplete tooth fracture or cracked tooth
i. Comminuted fracture
syndrome
ii. Lateral, facial or lingual fracture of alveolar socket
iii. Fracture of the alveolar bone with or without Division 2: Vertical fractures involving tooth crown
involvement of any tooth socket A. Fracture in an anterior or posterior tooth where the
fracture line passes buccolingually in the crown
B. Soft Tissue Injuries B. Fracture in an anterior or posterior tooth where the
Concomitant with most dental injuries is trauma to the fracture line passes mesiodistally through the crown
surrounding soft tissues including the facial skin, lips, Division 3: Vertical fractures involving tooth roots
oral mucosa, gingiva, frenum, soft tissues of hard/soft
palate and the tongue. A. Fracture in an anterior or posterior tooth where the
fracture line passes buccolingually in both the crown
and root or in the root only
Loomba’s Classification
B. Fracture in an anterior or posterior tooth where the
Loomba et al (2010) classified tooth fracture based on
fracture line passes mesiodistally through both the
treatment need.
crown and root or the root only.
Type I: Fractures of the anterior teeth in horizontal or
Type IV: Oblique fractures involving crown, root or
transverse plane
both in the anterior or posterior teeth.
Division I: Fractures of tooth crown
A. Fracture in incisal one-third up to the junction of the ROOT FRACTURE
incisal and middle third of the crown either partial
Root fracture is defined as ‘the fracture involving dentin,
or complete
cementum and pulp’. Root fracture is mainly categorized
B. Fracture in the middle one-third up to the junction as (i) horizontal/transverse fracture and (ii) vertical
of the middle and cervical third of the crown, either fracture. Horizontal fracture is more prevalent; occur
partial or complete mainly in anterior region of maxilla (maxillary incisors).
C. Fracture in the cervical one-third up to the cervical The middle region of the root is mostly involved
line of the crown, either partial or complete followed by apical and coronal. The vertical root
fracture (extends through long axis of root towards the
Division 2: Fractures of the tooth root
apex) is comparatively rare.
A. Fracture in the cervical one-third up to the junction
Vertical root fracture is characterized by an
of the cervical and middle third of the root
incomplete or complete fracture line that extends
B. Fracture in the middle one-third up to the junction through the long axis of the root towards the apex
of the middle and apical third of the root (Fig. 26.1a to c). In anterior teeth, the fracture occurs
C. Fracture in the apical one-third of the root most commonly in a buccolingual direction. In molar
teeth, the fracture is buccolingual in orientation to
Division 3: Fractures involving both the crown and root
individual roots. Mesiodistal fractures are less common
or at multiple sites
in both anterior as well as posterior teeth.
Type II: Fractures of the posterior teeth in horizontal
or transverse plane
The diagrammatic representation of types of root
fracture is summarized in Table 26.2.
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 466 Essentials of Endodontics

a b c

Fig. 26.1 Vertical root fracture: (a) Incomplete fracture at the buccal aspect of mesial root of a mandibular molar;
(b) Cross-section of a vertically fractured maxillary premolar showing complete fracture from the buccal to the lingual
aspect: One root canal; (c) Complete fracture from the buccal to the lingual aspects of maxillary premolar: Two root
canals

Table 26.2 Types of root fractures (diagrammatic representation)

Horizontal/transverse Vertical
Location Cervical Separation of Complete (fragments
fragments move independently)

Middle Incomplete (fragments

string together)

Apical

26 (Contd…)

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 Traumatic Dental Injuries and Management 467

Extent of fracture Partial

Total

Fracture lines Single Fracture position Complete intra-osseous

(relative to alveolar (loss of periodontal
crest) attachment)

Multiple

Comminuted

Position of Displaced Supra-osseous

coronal segment (coronal to alveolar
crest; no periodontal
defect)

Not displaced

(Contd…)
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 468 Essentials of Endodontics

Transverse root From occlusal/incisal Supra-osseous (apical

fracture edge to alveolar crest to alveolar crest; shallow
periodontal defect)

From alveolar crest

to 0.5 mm below

From 0.5 below

alveolar crest
(anywhere) apex
of root

It is established that smaller the mesiodistal diameter Class 3: When fracture line is within the coronal third
of the root, the greater the incidence of fracture. of root and below the level of the alveolar crest.
Premolars, mesiobuccal roots of upper molars, and Class 4: When fracture line extends middle third of root,
mesial roots of lower molars have these characteristics. below the level of alveolar crest.
The greatest incidence of vertical root fracture occurs Class 5: When fracture line is in the apical third of the
in endodontically treated teeth, and in patients older root.
than 40 years of age. Premolars are the most susceptible
teeth for vertical fracture followed by molars, incisors b. Chin-Jyh Yeh Classification
and canines. Mesial root of mandibular molar is Four patterns of root fractures are recognized in this
considered to be more susceptible. classification:
The root fracture comprises 1.0–7.0% of the total i. Vertical fractures: Fracture line parallel to long axis
dental traumatic injuries. These fractures mainly affect of the root and located only in root.
permanent dentition in the young age (10–20 years).
ii. Oblique fractures: Fracture line follows an angle in
Classification of Root Fractures relation to the long axis of the root.
Various authors have classified root fractures; the iii. Horizontal fractures: Fracture line perpendicular to
important ones are: long axis of the root.
iv. Laminar fractures: A piece of root fragment, not
a. Heithersay and Morile Classification
involving root canal.
Heithersay and Morile classified root fracture on the
basis of the level of root fracture in relation to various c. Enrique Basrani Classification
horizontal planes of the periodontium. Enrique Basrani classified fracture on the basis of
Class 1: When the fracture line does not extend below direction, location, number, extension and position of
the level of attached gingiva (occurs in aged root fragments.
patients where the clinical crown is larger than
anatomical crown). i. On the basis of direction
• Horizontal
26 Class 2: When the fracture line extends below the level
of attached gingiva but not below the level of
alveolar crest.
• Oblique
• Vertical

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 Traumatic Dental Injuries and Management 469

ii. On the basis of location Etiology

• Cervical third The etiology of vertical root fracture may not be definite;
• Middle third however, following factors play an important role.
• Apical third • Excessive canal shaping during endodontic
iii. On the basis of number of root fragments treatment contributing to weakening of the root;
• Simple subsequently, the vertical root fracture.
• Multiple • Excessive pressure during lateral or vertical
• Comminuted compaction.
iv. On the basis of extension of fracture line • Wedging effect of endodontic posts (diameter and
• Partial shape of the post).
• Total • Corrosion of posts, leading to expansion.
v. On the basis of position of root fragments • Inappropriate choice of abutment; unfavorable forces
• Without displacement on abutment.
• With displacement Clinical Features
The accepted classification for horizontal/transverse The clinical signs and symptoms vary according to the
root fracture is based on the following features: type of fracture, position of fracture, periodontal and
1. Location of fracture line bony architecture around the fractured tooth. The
• Cervical clinical features are:
• Middle • Swelling of soft tissue over the root
• Apical • Presence of sinus tract around the affected root
2. Extent of fracture • Tenderness
• Partial • Repeated dislodgement of post and post-core
• Total restoration
3. Fracture lines • No resistance during compaction of gutta-percha
• Single • Cracking sound during compaction or cementation
• Multiple of post
• Comminuted
Diagnosis
4. Position of coronal segment
• Displaced The patient’s dental history along with clinical and
radiographic findings are important to diagnose vertical
• Not displaced
root fracture. The following features are helpful:
5. Transverse root fracture
• Age of patient
• From occlusal/incisal edge to alveolar crest
• Root canal treated teeth
• From alveolar crest to 0.5 mm below
• Degree of mobility
• From 0.5 below alveolar crest towards (anywhere)
• Type of post and core restoration
apex of root
• Pain/tenderness
The accepted classification for vertical root fracture • Presence/absence of swelling
is based on the following features: • Presence of sinus
1. Position of fracture in relation to alveolar crest • Periodontal defect adjoining one tooth/root
• Incomplete supraosseous fracture, terminating The following tests can be significant in diagnosing
coronal to the alveolar crest (no periodontal defect) vertical root fracture:
• Incomplete supraosseous fracture, terminating
slightly apical to the alveolar crest (creating i. Bite test
shallow lesion) The bite test is carried out to simulate masticatory
• Complete/incomplete intraosseous fracture forces. Rubber wheels or cottonwood sticks are placed
resulting in loss of periodontal attachment. on mesial/distal/palatal areas of tooth to replicate
masticatory stresses.
2. Based on separation of fragments
• Total separation; fragments move independently ii. Periodontal probing test
(complete fracture)
• No separation; fragments string together
(incomplete fracture)
A periodontal probe can be used to evaluate perio-
dontal defect in the gingival attachment. In the absence
of any other associated periodontal disease, this defect
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 470 Essentials of Endodontics

may be consistent with an underlying bony dehiscence like’ appearance, traversing circumferentially
that is secondary to a vertical root fracture (Fig. 26.2a). around the root. The radiolucent area may also
A common feature of vertically root fractured teeth superimpose upon one side of the root. The bone
is the development of deep and narrow periodontal loss is dependent on the extent of destruction, the
pockets adjacent to the fracture site. plane of fracture and the architecture of the bone
The probing pattern for a tooth with a vertical root adjacent to the fracture. Bone destruction asso-
fracture is different as compared to teeth with perio- ciated with anterior teeth will be easier to detect
dontal disease. Deep probing in one position around than those associated with molars.
the circumference of the tooth usually indicates that – The widening of periodontal ligament space
the tooth is fractured (Fig. 26.2b). Deep probing in two around the whole length of the root is an indicative
positions on opposite sides is also indicative of fracture. of vertical fracture.
– Step-like bone defects appear when the fracture
iii. Pulp vitality tests
runs obliquely across the root or where the
The pulp vitality tests may not be reliable, especially fracture does not extend into the apical portion.
during early stages. The injured pulp may not response Additional radiographic examination with the
to such tests for at least 6 to 8 weeks after the injury. X-ray beam angled 15° to the mesial/distal may
The pulps usually retain vitality following an intra- provide a better view of the defect.
alveolar root fracture. The collateral circulation
– Isolated horizontal bone loss in molars
established by a fracture line often allows for
maintenance of pulp vitality. In vertical root fracture, – Resorption along the fracture line
the tooth may become hypersensitive to electric pulp – Dislodgement of retrograde filling material
testing. The clinical features and diagnosis of traumatic
dental injuries are summarized in Table 26.3.
iv. Radiographic examination
The following features should be evaluated:
CRACKED TOOTH SYNDROME
• Separation of root fragments
• Fracture lines along the root or root fillings: A It is reported that 80% of patients over 40 years of age
fracture line that deviates from the long axis of the may exhibit cracked teeth. The incidence and pre-
canal may be radiographically more obvious; valence of cracked teeth were commonly associated
whereas, a fracture line running parallel and adjacent with intracoronal restorations; most prevalent in
to a root filling may be less prominent. mandibular molars. The wedging effect of the promi-
nent mesiopalatal cusp of the maxillary first molar may
• Vertical root fracture is suspected if the root filling
account for this fracture. Non-functional cusp may be
appears well condensed but is in close contact with
more susceptible to fracture than functional cusp
only one wall of the root canal.
because they are subjected to lateral excursive occlusal
• Appearance of a space between the post and the edge forces. Cracks may initiate from the coronal structure
of a root canal. or from within the pulpal side.
• Overlapping of the fragments may result in double
Cracked tooth syndrome has been defined as ‘an
images of the external root surface.
incomplete fracture of a vital posterior tooth involving the
• Certain specific patterns of bone loss evident with dentin and possibly the dental pulp.’ Cameron coined the
vertical root fracture are: term ‘cracked tooth syndrome’.
– ‘Halo like’ bone loss: In case of a vertical root Incomplete tooth fracture is defined as ‘a fracture
fracture the bone loss has a tendency to give a ‘halo plane of unknown depth and direction passing through
tooth structure that if not already involving, may progress
to communicate with the pulp and/or periodontal
ligament’.
Diagnosis and management of cracked tooth is
always a challenge in clinical practice. It is important
to differentiate between dentinal, pulpal and periodontal

26 pain before planning any treatment. Early diagnosis is

a b

Fig. 26.2 Periodontal probing: (a) Soft tissue swelling over important in the treatment of cracked teeth to limit the
fractured site; (b) Periodontal pocket at the fracture site propagation of the cracks.

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 Table 26.3 Clinical features and diagnosis of traumatic dental injuries
Injury Clinical signs Percussion test Mobility test Pulp test Radiological findings
Avulsion Teeth are completely Not indicated Positive Not indicated Tooth seems elongated in
displaced out of their socket
socket
Intrusion Tooth intruded axially in Not indicated Negative May respond abnormal Periodontal space reduced
socket
Extrusion Tooth partially Tender to Mobile May respond abnormal Periodontal space increased
displaced out of percussion
socket
Subluxation Tooth not displaced Tender to Slight mobility May respond abnormal No change
in socket percussion
Luxation Tooth slightly displaced Not indicated Slight mobility May respond abnormal Periodontal space increased
in socket
Concussion Injured tooth is not Tender to Negative Normal response No radiological abnormality
displaced percussion
Enamel infraction Fracture of enamel Not indicated Negative Not indicated No change
without affecting tooth
Alveolar fracture Several teeth move as Tender to Several teeth move May respond as hyper- A visible fracture at alveolar
a unit when mobility is percussion as one unit active pulp bone
checked
Root fracture Tooth may be displaced Tender to Upper portion mobile May respond as hyper- A visible fracture in root
slightly percussion active pulp
Crown fracture (no Fractured crown without Non-responsive Only crown mobility Normal response Fracture visible in crown
pulp involvement) involving pulp

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Crown fracture Fractured crown with an Tender to Only crown mobility Abnormal response, Fracture visible in crown
(pulp involved) exposed pulp percussion depends upon pulp
involvement
Crown-root Fractured crown-root Not indicated Positive Abnormal response, Fracture may and may not
fracture structure depends upon pulp be visible
involvement
Traumatic Dental Injuries and Management
471

26
 472 Essentials of Endodontics

Classification of Cracks B. Luebke’s classification: Luebke classified cracks into

three classes:
Over the years, various authors have classified cracks;
the routinely mentioned are: Class 1: Incomplete, supraosseous with no periodontal
defect
A. American Association of Endodontists Classification Class 2: Incomplete, intraosseous with a minor perio-
identifies five types of cracks that are located in the dontal defect
crown and root as well as vertical root fractures that Class 3: Complete or incomplete, intraosseous with a
originate from the root (Table 26.4). major periodontal defect

Table 26.4 American Association of Endodontists classification for cracked teeth

Nomenclature Diagrammatic Origin Direction Symptoms Pulp status Prognosis
Craze lines Crown Variable None Vital Excellent

Fractured cusp Crown Mesiodistal and Mild pain Usually vital Good
faciolingual generally, only
to biting and
cold

Cracked tooth Crown Mesiodistal often Acute pain Variable Questionable;

± root central on biting, depends on depth
occasionally and extent of the
sharp pain to crack
cold

Split tooth Crown Mesiodistal Marked pain on Often root filled Poor; unless crack
± root chewing terminates just
subgingivally

Vertical root Roots Faciolingual Vague pain, Mainly root filled Poor; root resection
fracture mimics perio- in multi-rooted teeth
dontal disease

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 Traumatic Dental Injuries and Management 473

C. William’s classification: William divided cracks into c. Fractured crown

four categories: i. No pulpal involvement
Category 1: Incomplete vertical fracture through the ii. Pulp involved
enamel into the dentin but not into the pulp. d. Fractured root tip
Category 2: Incomplete crown fracture involving the F. Clark’s classification: Clark classified cracks into
pulp. three types:
Category 3: Incomplete vertical fracture crossing the Type 1: Little or no risk of underlying pathology.
attachments. Type 2: Moderate risk of underlying pathology.
Category 4: Fracture divides the tooth completely. Type 3: High risk of underlying pathology.
D. Talim and Gohil’s classification: Talim and Gohil G. William Kahler’s classification: William Kahler
classified cracks into four classes: classified cracks into following five types:
Class 1: Fracture involving the enamel i. Craze line
a. Horizontal or oblique. ii. Fractured cusp
b. Vertical iii. Cracked tooth
i. Complete iv. Split tooth,
ii. Incomplete v. Vertical root fracture

Class 2: Fracture involving enamel and dentin without MANAGEMENT OF PATIENT WITH DENTAL TRAUMA
involving the pulp
Traumatic dental injuries, as a part of emergency, need
a. Horizontal or oblique. immediate attention. The urgency is both for the
b. Vertical patients and the operator. The planned and organized
i. Complete approach to diagnosis and treatment help overcome
ii. Incomplete psychological problems of the patient and get better
outcome of the results. The long term prognosis of
Class 3: Fracture involving enamel, dentin and the pulp traumatized teeth is dependent on the quickly provided
a. Horizontal. emergency management.
b. Vertical The traumatic injury may involve intraoral and/or
i. Complete extraoral sites, which is usually contaminated with
ii. Incomplete blood and debris. The injury sites must be cleaned with
mild detergents prior to examination.
Class 4: Fracture of roots (based on direction of the The following steps provide necessary information
fracture line) to establish the correct diagnosis and plan the treatment.
a. Vertical or oblique
A. Medical and dental history: It is essential to establish
i. Involving the pulp any possibility of drug or any other allergies, blood
ii. Not involving the pulp disorders or other systemic conditions that may
b. Horizontal influence the treatment. The dental history should
i. Cervical third include the following questions:
ii. Middle third a. Whether the patient is conscious or unconscious?
If unconscious, provide immediate medical attention.
iii. Apical third.
b. When did the injury occur?
E. Pruden’s classification: Pruden classified cracks as: The time elapsed since the injury occurred is impor-
a. Crack line tant, especially in avulsion and displacement cases.
i. No separation of parts, no pain symptoms. c. Where did the injury occur?
The site of injury is important in evaluating the extent
ii. No apparent separation, but tooth is sensitive to
of trauma; for example, blow to the chin may transmit
percussion or patient has a persistent/vague pain,
to the condyles.
not definitely related to the tooth.
d. Is there a change in bite?
b. Fractured cusp
i. No pain or pulpal involvement
ii. Possible pulpal involvement
Changes in occlusion following an injury would
indicate a possible tooth luxation, alveolar bone
fracture, or condylar fracture.
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 474 Essentials of Endodontics

e. Is there increased sensitivity to temperature changes? change in treatment and also evaluate the treatment
Observe and note in teeth with crown fractures outcome or complications, if any. The splint applied to
exposing the dentin and/or pulp. the luxated teeth can usually be removed after three to
four weeks. Radiographic examination should be
B. Clinical examination: Clinical examination includes performed to analyze the possible initiation of root
evaluation of any soft tissue wounds, including resorption or periradicular lesion. After 6 weeks, clinical
examination for the presence of impacted foreign bodies and radiographic examination may reveal evidence of
in the wounds. Almost all lip wounds have impacted pulp necrosis and infection. At 3–6 months, it is
foreign bodies. The teeth are examined for any fracture necessary to establish definitive diagnosis of pulpal/
or craze lines. The former is easily observed visually periodontal healing. One year is a minimum observa-
while the latter requires directing the light parallel to tion period to assess the final outcome of traumatic
the tooth’s labial surface. If the crown fracture has dental injuries.
occurred, note whether the pulp is exposed and also
the extent of pulp exposure. Any displacement of teeth Management
must be noted and recorded as lateral or axial luxation. The traumatized teeth should be repositioned to achieve
C. Diagnostic tests: The following tests are helpful in acceptable function and appearance. The repair of
arriving at the diagnosis: fractures and proper positioning of periodontal soft
a. Mobility test: The degree of mobility of individual tissues provide the requisite function and appearance.
tooth or group of teeth is determined and noted. The treatment protocol can be:
b. Percussion test: The percussion test is carried out to • Early treatment: Injuries like tooth avulsions, alveolar
analyze damage to periodontal ligament. It should fractures, extrusive and lateral luxations and possibly
be performed gently. Tap first with the finger tip, root fractures require early treatment. The passage
followed by mirror handle. Adjacent tooth should of time affects the treatment outcome. Early
be percussed first. Percussion can provide informa- repositioning and stabilizing promote the healing.
tion about the relationship of the tooth and the • Partially delayed treatment: Injuries like subluxation and
adjacent bone; a high, metallic tone indicates lateral crown fracture with pulpal exposure can be delayed
or intrusive displacement. Such a percussion tone up to 24 hours without much affecting the results.
would indicate ankylosis of the tooth in follow-up • Delayed treatment: The treatment of crown fractures
examination. without pulpal exposure can be delayed as per desire
c. Pulp sensitivity test: The pulp sensitivity of a of the patient or the operator.
traumatized tooth can be evaluated by the use of a The management involves treatment of both soft and
heat, cold and/or electrical pulp tester. The hard tissues.
placement of the electrode should be at the junction
of middle and cervical third of the crown of anterior Management of Soft Tissue Injuries
teeth. Pulp sensitivity tests are usually helpful in Following the initial evaluation of any life threatening
anterior teeth. condition and resuscitation, injuries to the soft tissues
The lack of response to electric pulp tester should should be evaluated.
not be taken as pulp necrosis. The response immediately Facial injuries can be superficial or may involve
after injury may not provide accurate information. adjacent structures including bones, muscles, glands,
and/or dentoalveolar structures. Lacerations involving
D. Radiographic examination: A couple of radiographs the scalp can occasionally be difficult to control with
from different angulations provide the most reliable
pressure and may require clamping and/or electro-
information about the changes in the dentoalveolar cautery.
complex. This is important in case of root fractures since
The length of time from initial injury to treatment is
the single exposure may fail to demonstrate the
important in any injury, so is in soft tissue injury. The
diagonal root fractures. CBCT is also helpful in
risk of secondary infection increases as time lapses.
diagnosing vertical/oblique fractures. Another
Healing of facial wounds is usually unaffected by
application of radiography is to analyze the presence
interval between injury and repair. The tetanus
of impacted foreign bodies in the lips and adjoining
prophylaxis is recommended as:
soft tissues.

26 E. Follow-up evaluation: Follow-up evaluation is

important to confirm the diagnosis, determine need for
• If the patient has not received a booster injection
within the last 10 years, a booster injection is given
for any wound.

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 Traumatic Dental Injuries and Management 475

• Patients who are immunized and have received a The wound is thoroughly debrided excising non-vital
booster injection within the last 10 years do not tissue in an attempt to salvage most of the tissue. Soft
require tetanus prophylaxis if the wound is not tissue wounds are often contaminated with bacteria and
tetanus prone (Tetanus-prone wounds are those foreign material. Foreign bodies, if present, are removed
which are heavily contaminated, devitalized tissue, properly (continuous irrigation is mandatory).
or deep puncture wounds). If the wound is tetanus Thumb rule is to avoid irrigating the wound with any
prone and the patient has not received a booster solution that is not considered suitable for irrigating the
injection within 5 years prior to the injury, a 0.5 ml eye. A scrub brush and detergent soap may be necessary
tetanus toxoid booster injection should be given. to remove deeply embedded foreign material. However,
soaps may cause cellular damage and necrosis.
Sequence of Treatment Polymyxin B sulfate can be used to remove the greasy
Treatment of soft tissue injuries involves early portion in the wounds. Infections are rare when the
reconstructive procedures addressing both the soft wound is properly closed removing devitalized tissue
and/or foreign bodies from beneath the sutured skin.
tissue and the underlying bony injury, if any. The
common soft tissue injuries are categorized as follows: Suturing is preferred for facial lacerations maintain-
ing the esthetic considerations. A layered closure is
i. Lacerations: Lacerations, caused by sharp injuries, necessary to eliminate dead space beneath the wound.
contributes approximately 50% of such wounds. If the dead space is not obliterated, it may lead to
Lacerations usually have sharp and ragged accumulation of inflammatory exudates, subsequently
margins. Laceration wound should be sutured in tension and necrosis of the skin edges due to impair-
the center to avoid creating excessive tissue on the ment of the vascular supply.
end of the laceration. Ragged margins should be Deep layers should be re-approximated with suitable
excised to provide perpendicular skin edges to resorbable sutures. Margins should be undermined to
prevent scar formation. allow slight eversion of the wound margin. Skin sutures
ii. Abrasions: Abrasion wound implies removal of should be removed 6–7 days after placement. As the
superficial layer of skin. The wound should be wound heals, the collagen contract along its length and
gently cleaned with a mild soap solution and width and become inverted. Initial management is
irrigated with normal saline. Foreign bodies, if aimed at producing a slightly everted wound edge.
embedded in the wound, should be properly Tissue adhesives, such as cyanoacrylates, have been
removed. After the wound is cleaned, abraded skin used where esthetics was a priority; however, its use
is covered with a layer of topical antibiotic ointment should be avoided in complex lacerations.
to minimize desiccation and secondary infection.
Management of Hard Tissue Injuries
iii. Contusions: Contusions, caused by blunt trauma A. Enamel infraction
usually lead to edema and haematoma formation
Enamel infraction does not require any specific
in the subcutaneous tissues. Extensive swelling,
treatment. However, in case of multiple infraction lines,
ecchymosis are associated features. Small sized
the enamel surface is sealed with an unfilled resin. The
haematomas heal without any treatment, however,
surface, if not sealed, may take stains from food, drinks
large haematomas should be drained preferably to or even chromogenic bacteria.
prevent secondary subcutaneous atrophy.
iv. Avulsion: A loss of segment of soft tissue is referred B. Uncomplicated crown fracture
to as avulsion injury. Small defects are closed by The fractured portion of crown should preferably be
primary closure; whereas, large wound areas are restored. Bonding of original fragments can also be tried
allowed to heal by secondary intention or surgically if the separation is minimal. The tooth may not respond
grafting soft tissue grafts. initially to pulp test (vitality should be checked
periodically).
Local anesthesia is used effectively to clean the soft
tissue wounds. Local anesthetics containing epine- C. Complicated crown fracture
phrine have been used in routine in all areas of the face; Complicated crown fracture generally lead to pulp
however, epinephrine is avoided where extensive exposure. Root canal treatment is preferred; rarely
undermining of the soft tissue is necessary. One should pulpotomy can also be effective. Mineral Trioxide
avoid injecting directly into the wound. Regional nerve
blocks are considered beneficial since the blocks prevent
distortion of the tissues.
Aggregate is the material of choice; however, calcium
hydroxide can be also used. Fiber post reinforcement
is effective along with splinting (Fig. 26.3 a to e).
26

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 476 Essentials of Endodontics

a b c

d e
Fig. 26.3 Management of complicated crown fracture with fiber post reinforcement and resin splinting. (a) Crown fracture;
(b) Resin splinting; (c) Fiber post reinforcement; (d) Tooth preparation; (e) Restored tooth

D. Cracked tooth syndrome a. Horizontal root fracture

The treatment protocol for cracked teeth is explained Horizontal root fracture is usually located at the apical
in Flowchart 26.1. and middle half of the root. Such fractures are
characterized by rupture of hard structures of the root;
E. Crown-root fracture subsequently separating the tooth into two fragments;
The management of crown-root fracture may have the the apical segment is not usually displaced and the
following options depending upon the clinical condition: coronal segment is often displaced.
• Removal of mobile fragment when approximation The following factors should be considered before
is difficult. planning the treatment (treatment mainly depends
• Reattachment of fractured fragment with bonding upon status of pulp and mobility of coronal segment):
procedure. i. Position of the coronal segment after fracture
• When fracture extends subgingivally, bonding is ii. Mobility of coronal segment
difficult; hence, gingivectomy is performed to iii. Site of fracture
convert the subgingival fracture into a supragingival iv. Status of the pulp
fracture. The fiber reinforced esthetic post may also v. Access to oral environment
be used to aid in the retention of fractured segment. vi. Age and sex
• Orthodontic extrusion of the apical fragment may help
bring the subgingival margin to supragingival position. i. Position of tooth following fracture: The teeth
• Surgical extrusion of the apical fragment can be following fracture are usually lingually placed and
carried out in teeth with long roots. slightly extruded. The treatment protocol involves
reduction of displaced coronal fragment and
F. Root fracture immobilization. It is established that if treatment is
Root fracture can be either horizontal or vertical. The initiated immediately, repositioning of the fragment is

26 common factors which lead to root fracture are related

to root morphology, deviant masticatory habits and
excessive occlusal forces.
easily achieved. If resistance is felt during repositioning,
it is most likely due to fracture of the labial socket wall.
In this case repositioning of the fractured bone is

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 Traumatic Dental Injuries and Management 477

Flowchart 26.1 Treatment protocol of cracked teeth Generally the prognosis is good for apical and mid-
root fracture, while it is questionable in case of cervical
root fracture.
Horizontal root fractures at the level of the perio-
dontal attachment have generally a poor prognosis. The
treatment involves a combination of endodontic,
orthodontic, periodontic and restorative therapy.
In case of cervical-third fractures, the treatment depends
upon length of the remaining root and the availability
of coronal segment. The treatment options can be:
• Fractures below the alveolar crest can be treated by
conventional means by stabilizing the fractured
segments. The splinting should be kept for a longer
period (say 4–6 months), maintaining proper oral
hygiene. The occlusal/functional load should be kept
to a minimum.
• In case the coronal fragment is available and the
fracture is coronal to the alveolar crest, reattachment
of the fractured segment should be attempted. Both
the fractured surface areas are etched and bonded with
flowable adhesive restoration (slight undercut can be
created on both the fragments or a plastic pin can be
inserted on both the sides to achieve better retention).
• In case the coronal fragment is not available; fracture
line extends below the alveolar crest, the remaining
root is endodontically treated and restored with
appropriate post-core restorations.
• The remaining root can be extracted carefully and
adjusted at the requisite position; the fractured segment
is stabilized by interdental suturing and dressing (Intra-
necessary before reducing the root fracture. After reduc- alveolar transplantation of fractured root segment).
tion, the position should be verified radiographically. • In case the above mentioned modalities fail or not
Splinting for 6 to 8 weeks effectively reduces the feasible, extraction followed by implantation can be
fractured segments. carried out.
iv. Status of the pulp: Horizontal root fracture, especially
ii. Mobility of coronal segment: Root fractures in the
in a tooth with an open apex warrants maintenance of
apical third of the root without displacing the coronal
radicular pulp vitality to allow continued root formation.
fragment do not require any splint. It has been shown
Immature teeth with incomplete root fractures may
that there is no difference in the outcome of treatment
heal by hard tissue union. However, these teeth may
between splinted and non-splinted teeth in such cases.
be splinted for better results. The tooth should be
However, splinting is necessary in mid root or cervical
observed radiographically and with vitality tests in
root fractures.
order to detect changes in pulp status, if any.
iii. Site of fracture: A root fractured in apical third area
v. Access to oral environment: In case the fracture line
has an excellent prognosis because the pulp in the apical
develops communication with oral environment (through
fragment usually remains vital, and the tooth may
gingival sulcus), the prognosis of union is poor (usually
remain firm in its socket. If the pulp in the coronal
the site of fracture gets contaminated with oral micro-
fragment remains vital and the tooth is stable (with or
organisms, which hinder with the repair process).
without ligation), then no additional treatment is required.
If the pulp in the coronal fragment gets necrosed, then vi. Age and sex: Younger age is favorable for healing
endodontic treatment limited to the coronal fragment can
be performed. If the tooth fails to recover, the apical root
fragment can be removed surgically.
(mostly traumatic injuries occur in young age); better
blood supply coupled with immunity facilitate hard
tissues formation at the fractured site.
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 478 Essentials of Endodontics

Healing of fractured segments is not related to sex; The various options are:
however, girls have shown early healing as compared • Root canal therapy of both the segments.
to boys. • Root canal therapy of coronal segment and removal
The treatment protocol of root fracture depending of separated apical segment (Fig. 26.4a to i)
upon condition of pulp and the mobility of coronal • Root canal therapy of coronal segment and no treat-
segment is explained in Table 26.5. ment for intact vital apical segment (Fig. 26.5a to d)

Table 26.5 Condition of pulp and mobility of coronal segment; recommended treatment of root fracture
Vitality (condition of pulp) Mobility of coronal segment Root canal treatment required Splinting required
+ – No No
+ + No Yes
– – Yes No
– + Yes Yes

a b c

d e f

g h i

Fig. 26.4 Root canal treatment of coronal segment and removal of fractured apical segment: (a) Fracture of left maxillary
central incisor (central incisor bonded to the lateral incisor); (b) Preoperative radiograph revealing root fracture;

26 (c) Removed apical fragments; (d) Root canal preparation of coronal fragment; (e) Evaluating root canal with endodontic
file; (f) Filling of the coronal fragment; (g) Completing obturation of coronal fragment; (h) Apical segment removed
surgically (four anterior teeth splinted); (i) Postoperative radiograph showing healing

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 Traumatic Dental Injuries and Management 479

a b c d

Fig. 26.5 The coronal portion is root canal treated up to the fracture line; the apical portion is left untreated (healing with
interposition of hard and soft tissue): (a) Preoperative radiograph showing horizontal root fracture of the left upper
central incisor; (b) Assessing the fracture segments; (c) Coronal fragment obturated with gutta-percha; (d) Postoperative
radiograph

a b c d

Fig. 26.6 Use of intraradicular splint connecting fractured segments: (a) Horizontal root fracture in the middle third of
root; (b) By-passing the fracture segment; (c) Interradicular splint inserted; (d) Splinting of the fractured teeth with healthy
teeth

• Root canal therapy of coronal segment with mineral file inside the root canal. Anderson recommended that
trioxide aggregate (MTA) as apical barrier detection of a sinus tract emanating from the coronal frag-
• The use of intraradicular splint connecting both the ment requires root canal treatment of that portion only.
segments (Fig. 26.6a to d) Mineral trioxide aggregate has also been used in
• Root extrusion—removal of coronal segment and managing mid root fractures. There is not sufficient
subsequent orthodontic or surgical extrusion of the documentation to evaluate clinical outcomes of root
remaining apical fragment canal treatment using mineral trioxide aggregate in
The horizontal mid root fracture with clinical signs teeth with horizontal root fractures; however,
of pulpal necrosis can be treated by performing root individual case reports (Fig. 26.7a to i) are positive.
canal treatment on both the segments. The fragments
should be stabilized by inserting stainless steel endodontic
The management of root fracture is summarized in
Table 26.6.
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 480 Essentials of Endodontics

a b c

d e f

g h i

Fig. 26.7 Mid-root fracture managed by mineral trioxide aggregate (MTA): (a) Preoperative radiograph showing mid-
root fracture; (b) By-passing the fracture segment; (c) Assessing the fracture segments with gutta-percha cone;

26 (d) Obturation of apical segment with gutta-percha; (e) Apical barrier between coronal and apical segments with
mineral trioxide aggregate; (f) Obturation of coronal segment with gutta-percha; (g) Postoperative radiograph;
(h) Coronal segment reinforced with fiber post and core; (i) Final restoration with a crown.

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 Traumatic Dental Injuries and Management 481

Table 26.6 Management of root fracture

Horizontal
Fracture at apical third • Retain the fragments (wait for natural healing)
• Root canal treatment of both the fragments (minimum or no mobility of fragments)
• Root canal treatment of both the fragments followed by stabilizing the fractured segments
(mobility of fractured segments)
Fracture at middle third • Reduction and stabilization
• Root canal treatment of both the fragments followed by stabilizing the fractured segments
(mobility of fractured segments)
Cervical third area • Reattachment if coronal segment available and fracture is above the alveolar crest
• Stabilization, if fracture site below the alveolar crest
• Crown lengthening if fracture site is within 3.0 mm of the gingival crevice area, followed by
conventional root canal treatment and post-core restorations
• Surgical extrusion/orthodontic extrusion, followed by conventional root canal treatment and
post-core restorations
• Extraction, if other treatments fail/not feasible
Vertical
Partial/complete • Extracting the fractured root; bonding the fractured segments with adhesive and reimplanting
in 180° rotation (rotation facilitates periodontal ligament attachment)
• Application of bioresorbable membrane followed by stabilization and reduction

Prognosis Healing of Root Fracture

Successful treatment of horizontal root fractures have The healing of root fracture depends upon the site of
been reported in literature. Additional findings, such fracture and the status of pulp. The wound healing is
as pulp canal obliteration, external and internal surface initiated both from pulpal and periodontal ligament
resorption have been observed along with healing side.
modalities. If the pulp is intact after fracture, the odontoblastic
b. Vertical root fracture progenitor cells create a hard tissue bridge uniting the
Generally, prognosis is poor with vertical root fracture, fractured fragments, followed by cementum deposition
especially in single rooted teeth. In multirooted tooth, derived from the periodontal ligament cells obliterating
radisectomy can be helpful. the fracture site.
The vertical root fracture can be treated by extracting The fate of the injured pulp depends upon
the fractured tooth atraumatically, bonding the revascularization from the periodontal ligament sites.
fragments (adhesive resin/4-meta resin used as In case the pulp is severely stretched at the level of
bonding agent. Lasers have also been tried) and then fracture, the revascularization process is initiated from
replanting the tooth with a 180° rotation. The rotation the coronal pulp. If bacteria gain access during the
of the tooth facilitates connection of the healthy process, it may lead to necrosis of coronal pulp.
periodontal membrane to the fractured root. The Clinical and radiographic follow-ups are necessary
application of bio-resorbable membrane on root to evaluate pulp necrosis. Extrusion of the coronal
surfaces reinforces the periodontal healing. It allows fragment, tenderness to percussion, and the radio-
regeneration of periodontal ligament cells, providing graphic signs of pulp necrosis can usually be detected
space for the in-growth of periodontal ligament tissues. within the first two months after injury.
Fractured roots that radiographically reveal less A negative sensibility response immediately after
space between the fragments after repositioning usually injury does not necessarily indicate pulp necrosis.
heal with hard tissue repair than those with more space However, it has been observed that teeth which did
between the fragments. Reduction is also important for not respond to pulp testing immediately following root
eliminating the blood coagulum between the fragments, fracture demonstrated significantly greater risk of pulp
which is the substrate for bacterial growth. necrosis.
Ankylosis is a common complication of replanted The periodontally derived cells help in root fracture
teeth leading to a gradual resorption of the dental hard healing by interposition of connective tissue. During
tissues and their replacement by bone. The vitality of
the periodontal membrane was reported to be of critical
importance in preventing ankylosis.
the initial stage of wound healing, the inflammatory
response trigger series of osteoclastic activities,
subsequently obliterating the fracture site. The pattern
26

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 482 Essentials of Endodontics

of healing may eventually lead to resorption. The types fragment continues to erupt while the apical fragment
of resorption can be: remains stationary). Interposition of bone and
• External surface resorption surrounding the connective tissues is seen along the fracture site.
proximal fracture edges at the periodontal side of Radiographically, a bony bridge is seen separating
the fracture. the fragments with a periodontal ligament space around
• Internal surface resorption surrounding the fracture both the fragments. Pulp canal obliteration of the root
edges centrally at the pulpal side of the fracture. canals in both fragments is a common finding. Clinically,
• Internal tunneling resorption burrows behind the the teeth are firm and react normally to pulp tests.
predentin layer and along the root canal walls of the iv. Interposition of granulation tissue
coronal fragment. The fractured site is obliterated with granulation tissue.
The resorption processes are usually self-limiting and The coronal portion is usually necrotic, while the apical
resolve within first one to two years after injury. portion remains vital. The necrotic pulp tissue is respon-
The pattern of healing of root fracture may vary. The sible for inflammatory changes along the fracture line.
possible patterns can be: Radiographically, widening of the fracture line, loss of
i. Healing with calcified tissue lamina dura and rarefaction of the alveolar bone
The calcified tissue, simulating dentin, osteodentin corresponding to the fracture line are common findings.
and/or cementum is formed at the fracture site. The
Follow-up
innermost layer of repaired tissue simulate dentin;
whereas, the peripheral portion is repaired with A standard follow-up protocol should be followed
cementum. The connective tissue may not completely based on clinical information and sensitivity tests. Laser
bridge the gap between the fracture surfaces, but is Doppler evaluation can be helpful in demonstrating
interspersed all along the fractured area. A slight early revascularization of the coronal pulp. The radio-
widening of the root canal close to the fracture site may graphic examination should be carried out periodically
be seen after the hard tissue formation. to evaluate the healing pattern.
This type of healing depends upon the intact pulp G. Luxation injuries
and is seen primarily in cases with little or no Luxation injuries account for 15.0 to 60.0% of traumas
dislocation of the coronal segment. Clinically, the tooth in primary and permanent teeth. Accidents and fights
appears normal in these conditions. are the main reasons for such injuries. Six types of
ii. Healing with interproximal calcified tissue luxation lesions are recognized (Fig. 26.8):
The healing is characterized by the presence of i. Concussion
connective tissue between the fragments. The fracture ii. Subluxation
surfaces are covered with connective tissue fibers iii. Extrusive luxation
running parallel to the fracture surface or from one iv. Lateral luxation
fragment to the other. v. Intrusive luxation
A common finding is peripheral rounding of the vi. Tooth avulsion
fracture site. In-growth of bony tissues into the fracture i. Concussion: It is a mild form of luxation injury,
area may also be seen. Radiographically, peripheral characterized by sensitivity to percussion only. No
rounding of the fracture edges and a radiolucent line displacement and no mobility is seen as a result of
separating the fragments can be visible. the injury (Fig. 26.8a). Treatment for concussion is
Initially, external and internal surface resorptions are symptomatic. Tooth is allowed to rest to promote
often seen, as well as pulp canal obliteration of both recovery of trauma to periodontal ligament and
apical and coronal aspect of the root canal. Clinically, apical vessels. Pulp status should be monitored by
the teeth are firm or may be slightly mobile. Long term pulp tester and the tooth should be periodontically
follow-up is mandatory, because the resorptive process clinically examined for any evidence of color
may lead to ankylosis. changes (Table 26.7).
This type of healing is related to extrusion or lateral ii. Subluxation: Subluxated tooth is mobile and sensitive
luxation with moderate pulp injury. to percussion (Fig. 26.8b). The pulp tests may result
in ‘no response’ or may be ‘positive’. Treatment
iii. Healing with interposition of bone and connective may not be required; alternatively, the tooth may

26 tissue
This mode of healing is a sequelae of trauma prior to
complete growth of the alveolar process (the coronal
be stabilized for a short period of time (Table 26.7).
Subluxated teeth need to be evaluated and
monitored regularly to evaluate the pulp status.

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 Traumatic Dental Injuries and Management 483

Fig. 26.8 Luxation injuries: (a) Concussion; (b) Subluxation; (c) Extrusive luxation; (d) Lateral luxation; (e) Intrusive luxation;
(f) Tooth avulsion

iii. Extrusive luxation: The tooth is axially displaced in establish a normal occlusal alignment within few
a coronal direction (Fig. 26.8c). The luxated tooth is weeks/months).
mobile and likely to have a premature contact with Monitor the progress of re-eruption of teeth; if tooth
opposing teeth. The tooth is immediately stabilized erupts in a natural position, no other treatment is
by functional splint for 4 to 8 weeks (Table 26.6). needed. Pulp status of tooth is also evaluated
Long stabilization period is preferred to realign the periodically. Root canal therapy is usually not
periodontal ligament fibers. Generally, the extrusive required.
luxated teeth require root canal therapy except in Recent guidelines advise no treatment if intrusion is
young, developing teeth in which the pulps are within 3.0 mm; however, intrusion up to 7.0–8.0 mm
more prone to recover. need repositioning using surgical/orthodontic/
iv. Lateral luxation: Traumatic injuries may result in combination of two means. Tooth is likely to get
displacement of a tooth labially, lingually, distally ankylosed if not treated on time.
or mesially. Such displacement is called lateral vi. Tooth avulsion: An avulsed tooth is completely
luxation (Fig. 26.8d). displaced out of its socket (Fig. 26.8f). Avulsion is
The lateral luxation cases are managed by reposition- considered as a dental emergency, since timely
ing and stabilization the tooth. Repositioning a attention could save such teeth. It has been
laterally luxated tooth may require pressure applica- established that immediate reimplantation of
tion at the apical end of the root in the direction of avulsed teeth leads to clinical success (Table 26.8).
the original root apex. Definitive treatment may The most important factor from the moment the
include root canal therapy (Table 26.6). tooth is avulsed from the alveolar socket is ‘time’.
v. Intrusive luxation: A tooth, during trauma, is pushed The increase of time between avulsion to reimplan-
apically; mostly firm in the socket (Fig. 26.8e). tation increases the danger of replacement resorption
Treatment depends upon the stage of tooth and decreases revascularization; subsequently
development (Table 26.6). No treatment is advised
for immature teeth (it is expected that tooth with
wide open apex has the potential to re-erupt and
compromising success.
Long term success depends on the storage medium and
also management of the root surface.
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 26
Table 26.7 Luxation injuries: Signs, symptoms and management
Tooth status Concussion Subluxation Lateral luxation Intrusion Extrusion
Clinical findings • No change in tooth position • Sensitive to percussion Tooth laterally • No mobility • Tooth sensitive to
• No mobility may increase repositioned • Metallic sound upon percussion
• Sensitive to percussion • May be slightly mobile percussion • Extruded tooth may be
• No change in tooth mobile
position • Visible gingival damage
Radiological No radiolucency No radiolucency Widened periodontal Absence of periodontal Widened periodontal
findings ligament ligament ligament
Treatment/ No treatment indicated Non-rigid splint for one • Anesthetize area and • Closed apex: Anesthetize area and push
484 Essentials of Endodontics

Management to two weeks push the tooth to Immediately return the tooth to its original
original position tooth to original position position
• Non-rigid splint for four by orthodontic eruption
weeks or surgical
• The tooth is selectively • In case of open apex,
grinded to minimize wait for natural eruption
occlusal forces • Periodic evaluation of
pulp status
Periodical follow-up Follow-up at 4 weeks, Evaluate pup status • Evaluate pulp status • Evaluate pulp status • Evaluate pulp status
8 weeks; up to one year • Root canal treatment • Root canal treatment • Root canal treatment
may be required may be required may be required
• Radiographic • Radiographic • Radiographic
confirmation confirmation confirmation
Patient instructions • Soft diet initially
• Brush/rinse with 0.2% chlorhexidine twice daily
• Antibiotics/analgesics according to the need

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 Traumatic Dental Injuries and Management 485

Table 26.8 Management of avulsed teeth

On-site treatment • Hold the tooth by the crown
• Wash and keep the tooth in oral cavity (saliva)
• Can be kept in milk/other storage medium, as available
• Refer patient to dental clinic immediately
Treatment in clinic Condition A Condition B Condition C
• Tooth replanted in the socket • Tooth stored in medium, such as • Tooth remained dry for more
saline solution or saliva (up to 2 hours than 60 minutes or longer than
after injury) or milk (up to 3 hours after recommended time in other
injury) or dry (less than 60 minutes) media
• The tooth is stabilized and • Remove tooth from medium and • Remove periodontal ligament
splinted gently apply antibiotic solution to fibers with gentle brushing and
the root surface place tooth in a topical fluoride
(APF 1.23% F–) solution for 15
minutes.
• Remove blood clot from
socket with normal saline.
Perform root canal extraorally,
reimplant the tooth and splint
Follow-up of the • Ensure correct tooth position within the socket
case • Selective grinding to relieve tooth from occlusal forces
• Periodic examination to evaluate status of pulp and surrounding tissues
Postoperative • Soft diet for two weeks
instructions • Rinse mouth with 0.2% chlorhexidine twice daily for a week
• Put patient on antibiotics, etc.

Storage medium iii. Saliva: Buccal vestibule is considered as a safe

Tooth should be immediately placed in a storage storage medium for avulsed teeth. However, saliva
medium to diminish injury to the periodontal has unfavorable characteristics, such as non-
ligaments cells. physiologic pH/osmolality, hypotonicity and
The storage media are: bacterial contamination.
i. Water
Artificial saliva is also not effective. Both artificial
ii. Normal saline
and human saliva is considered only if other
iii. Saliva
adequate media are not available.
iv. Coconut water
v. Egg white iv. Coconut water: Coconut water is pure, sterile
vi. Green tea/propolis natural product, rich in nutrients (amino acids,
vii. Milk vitamins and minerals). It is an effective storage
viii. Viaspan medium; comparable to milk and HBSS.
ix. Hanks balanced salt solution (HBSS) v. Egg white: Egg white is an excellent storage
x. Dulbecco’s storage medium medium because of its nutrients (proteins,
xi. Soymilk vitamins, water) along with absence of microbial
i. Water: Water is not a good medium for storage. contamination. It provides cell viability for a long
Its non-physiological pH/osmolality, hypotonicity period of time.
and bacterial contamination favor cell lysis of
vi. Green tea/propolis: Both green tea and propolis
attached periodontal ligament.
are anti-inflammatory, antibacterial and anti-
ii. Normal saline: Normal saline has physiological
pH/osmolality; however, it does not contain any oxidants. These have the potential to inhibit
prostaglandin synthesis facilitating phagocytic
essential nutrient (mainly glucose and proteins) for
the survival of cells. Saline is not considered as an
effective storage medium.
activities and promoting healing effects. Both are
very good storage medium.
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 486 Essentials of Endodontics

vii. Milk: Milk has physiological pH/osmolality, is Table 26.9 Characteristics and efficacy of storage medium
isotonic and contains growth factors/nutrients. Storage medium Characteristics Efficacy
Milk contains epithelial growth factor, which
Water • Non-physiological pH Nil (Poor)
proliferates epithelial growth factor, which
• Contaminated with
proliferates epithelial cell rests of Malassez. It is
bacteria and other aerosols
very good storage medium.
Normal saline • Physiological pH Poor
viii. Viaspan: Viaspan has physiological pH/osmolality
• Osmolality
and sufficient nutrients favoring cell growth. It is
• Easy availability
an excellent storage medium; however, it is not
Saliva • Non-physiological pH Poor
easily available. The high cost of the medium
makes it unviable for routine use. • Hypotonic
• Contaminated with micro-
ix. Hank’s balanced salt solution (HBSS): Hank’s organisms
balanced salt solution has physiological pH/ • Accessibility to patient’s own
osmolality, considered an excellent storage
saliva
medium. It contains nutrients for preserving the
Coconut water • Sterile and natural Good
vitality of cells.
• Contain nutrients
x. Dulbecco’s solution: Dulbecco’s solution has • Availability varies
physiological pH. It maintains intracellular/
Egg white • Contains nutrients (protein)/ Good
extracellular osmotic balance. It provides nutrients
water
(mainly glucose) for survival of cells. It is consi-
• Minimum bacterial
dered as an excellent storage medium.
contamination
xi. Soymilk: Soy milk has physiological pH (as
Green tea/propolis • Antibacterial Very good
compared to cow’s milk, it contains no cholesterol
• Antioxidant
and is fat free). It has the potential for cell
• Anti-inflammatory
proliferation. Soymilk, as a storage medium, is
comparable to HBSS solution and is superior to Milk • Physiological pH/osmolality Very good
Egg white and coconut water. • Contains growth factors
and nutrients
The characteristic features and efficacy of storage
• Minimum bacterial
media are summarized in Table 26.9.
contamination
Management of root surface • Isotonic
The management of root surface depends on the Viaspan • Physiological pH/osmolality Excellent
amount of time elapsed from the time of injury, • Favors cell growth
coupled with type of storage medium, if used. Hank’s balanced • Physiological pH/osmolality Excellent
A tooth that remains out of oral cavity and salt solution • Contains nutrients
remained in dry condition for less than 60 minutes Dulbecco’s • Physiological pH Excellent
or stored in one of the recommended mediums, solution • Maintain intracellular/
the root surface is soaked in 1.0 mg/10 ml extracellular osmotic
doxycycline for five minutes before reimplantation. balance
The use of antibiotics enhances the potential for • Provide nutrients
revascularization and even lower the frequency of
Soymilk • Physiological pH Very good
inflammatory root resorption. In the event that 60
• Facilitate proliferation
minutes have passed in dry condition or the tooth
of cells
remained in recommended medium for longer
period, then the tooth should be soaked in a
fluoride solution before reimplantation. In such (APF 1.23% F–) for 15 minutes slows down the

26
cases, replacement resorption is inevitable. process of resorption. It is advisable to perform
Therefore the goal is to make root more resistant root canal therapy outside the oral cavity
to resorption. Soaking the root in topical fluoride (Fig. 26.9a to g).

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 Traumatic Dental Injuries and Management 487

a b c

d e f

g
Fig. 26.9: Reimplantation of mandibular incisor: (a) Preoperative; (b) Avulsed tooth dipped in APF solution; (c) Preparing
root canal; (d) Apex resected; (e) Avulsed tooth placed back in the socket after root canal treatment; (f) Radiograph
showing splinting; (g) Periodontal pack placed

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21. Loomba K, Loomba A, Bains R and Bains VK. A proposal for
classification of tooth fractures based on treatment need. J. 39. Tsesis I, Rosen E, Tamse A, Taschieri S and Kfir A. Diagnosis
Oral Science: 2010; 52:517. of vertical root fractures in endodontically treated teeth based
on clinical and radiographic indices: A systematic review. J.
22. Main BG and Adair SR. The changing face of informed
Endod.: 2010; 36:1455–1458.
consent. Br. Dent. J.: 2015; 219:325.
40. Versiani1 MA, De Sousa CJ, Cruz-Filho AM, Da Cruz Perez
23. Majorana A, Pasini S, Bardellini E and Keller E. Clinical and
DE and Sousa-Neto MD. Clinical management and
epidemiological study of Traumatic root fractures. Dental
subsequent healing of teeth with horizontal root fractures.
Traumatology: 2002; 18:77–80.
Dental Traumatology: 2008; 24:136–139.
24. Metska ME, Aartman IH, Wesselink PR and Ozok AR.
Detection of vertical root fracture in vivo in endodontically 41. Walton RE, Michelich RJ and Smith GN. The histopatho-
treated teeth by cone beam computed tomography scans. J. genesis of vertical root fractures. J. Endod.: 1984; 10:48–56.
Endod.: 2012; 38:1344–1347. 42. Wang J and Li M. Multidisciplinary treatment of a complicated
25. Molina1 JR, VannJr WF, McIntyre JD, Trope M and Lee JY. crown-root fracture. Pediatric Dentistry: 2010; 32:250–254.
Root fractures in children and adolescents: Diagnostic 43. Westphalen VP, De Sousa MH, Da Silva Neto UX, Fariniuk LF
considerations. Dental Traumatology: 2008; 24:503–509. and Carneiro E. Management of horizontal root-fractured teeth.
26. Mozami F, Mirhadi H, Geramizadeh B and Sahebi S. Report of three cases. Dental Traumatology: 2008; 24:e11–e15.

26 Comparison of soymilk, powdered milk, Hank's balanced

salt solution, and tap water on periodontal ligament cell
survival. Dent. Traumatol.: 2012; 28:132–135.
44. Zadik Y, Sandler V, Bechor R and Salehrabi R. Analysis of
factors related to extraction of endodontically treated teeth.
O.Surg, O. Med, O. Path.: 2008; 106:e31–e35.

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 Chapter
27
Root Resorption

Root resorption, a multidisciplinary problem, is of

concern to the clinicians, especially the endodontists.
Root resorption is defined as ‘the progressive loss of dentin
and cementum through the continuous action of osteoclastic
cells (odontoclasts, cementoclasts and all clast cells, derived
from monocytes, which form macrophages)’. In bone,
continuous apposition and resorption occur as a part
of remodeling process. Early diagnosis, removal of the
cause, proper treatment and reinforcement of the
resorbed root is mandatory for achieving success.
Efforts should be directed towards maintaining
integrity and vitality of the periodontal ligament of
luxated and the displaced teeth.
The resorption can be physiological and pathological.
The resorption in primary dentition is physiological Fig. 27.2 Pathological root resorption
(Fig. 27.1); whereas, in permanent dentition, it is
pathological (Fig. 27.2). Roots of permanent teeth do
not undergo resorption normally. The cellular surface resorption). Physical/chemical injuries to this cellular
layer of odontoblasts and cementoblasts usually layer may lead to resorption. Atypical resorption of
provide immunity to the permanent dentition (root external root surface has been reported in primary
cementum from the side of periodontal ligament is dentition. This is not associated with pulp necrosis and
coated with precementum and cementoblasts; the tooth is generally asymptomatic. Radiologically,
odontoblasts and predentin protect dentin from dome-shaped or cone-shaped area can be seen on the
root surface involving periodontal ligament. It is co-
related with the habit of thumb sucking, which may
induce low intensity constant trauma. The resorption
is self-limiting and gets repaired as the cause is removed.
Rarely, abnormal positioning of permanent tooth germ
may lead to its resorption along with deciduous tooth.

Etiology
The phenomenon of root resorption has multiple causes
with varying hypothesis. The causes are broadly
divided into three; local, systemic and iatrogenic. High
temperature during cavity preparation/tooth prepara-
tion and calcium hydroxide in vital pulp therapy has
also been the source of stimulation of resorption.
The causes of root resorption are summarized in
Fig. 27.1 Physiological root resorption Table 27.1.

489

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 490 Essentials of Endodontics

Table 27.1 Causes of root resorption

Local causes Systemic causes Iatrogenic
• Tooth reimplantation (damage to perio- • Genetic disorders • High temperature during tooth
dontium) • Radiotherapy preparation
• Injuries/trauma • Hormonal disorders (hyperthyroidism/ • Vital pulp therapy with calcium
• Improper habits hyperparathyroidism) hydroxide
• Orthodontic force • Kidney/hepatic impairment • Irregular eruption of permanent
• Bleaching procedures • Paget’s disease teeth
• Pressure of tumor or cyst • Turner’s syndrome • Acute mechanical injury
• Invaginated teeth/dental abnormalities • Papillon-Lefèvre syndrome
• Aggressive periodontal treatment • Vitamin deficiencies, especially vitamin A
• Malocclusion • Hypertension
• Impacted teeth putting pressure on • Bone dysplasia
adjacent teeth
• Materials like silver nitrate may stimulate
resorption

Pathogenesis might be no resorption without this stimulation. The

It is established that cementum and periodontal pulp tissue apical to the resorptive lesion should have
ligament protect external root surface and predentin viable blood supply to provide clastic cells and their
protect the internal root surface. Damage to these nutrients; whereas, the infected necrotic pulp tissue
surfaces allow osteoclasts to bind to the surface of root; provide stimulation for these clastic cells.
and an inflammatory response may stimulate resorp-
tion. Persistent stimulation may lead to clinical Classification
resorption. It is hypothesized that cementum lacks those Root resorption may be categorized as internal and
proteins found in bone that stimulate osteoclastic external, depending upon the location of the resorption.
activity. It also has inhibiting factors for osteoclastic It may also be categorized as inflammatory and
activity. It is also hypothesized that non-collagenous replacement, depending upon the initiating factors.
components in predentin resist internal resorption. Few authors have also categorized root resorption as
The resorptive process is linked to osteoclasts (large systemic, inflammatory and idiopathic (Table 27.2).
multinucleate cells found within crypts on hard tissue
surfaces). Mechanism of hard tissue destruction by Table 27.2 Classification of root resorption
osteoclasts involves: Based on process • Physiological resorption
• Dissolution of inorganic hydroxyapatite by acids • Pathological resorption
produced by ruffled border of osteoclasts and Based on location • Internal
enzyme carbonic anhydrase II and acid phosphatase. • External/cervical
• Dissolution of organic matrix containing type 1 Based on initiating factor • Inflammatory
collagen by enzymes, such as collagenase and • Transient
cysteine proteinase. • Progressive
A significant stimulation is also associated with • Replacement
bacteria. In the presence of bacterial lipopoly- • Idiopathic
saccharides, leukocytes differentiate into osteoclasts.
Certain gram-positive species have been demonstrated The modified Andreasen classification is given in
to stimulate osteoclastic activity through osteoclast Table 27.3.
differentiation factors.
Odontoclasts, morphologically similar to osteoclasts, Table 27.3 Andreasen’s classification
(odontoclasts are smaller in size and have fewer nuclei Internal resorption External resorption
as compared to osteoclasts), resorb the largest tissue in • Internal inflammatory • External inflammatory
a similar manner. Both cells possess similar enzymatic resorption resorption (infection related)
activity and create resorptive lacunae on the surface of • Internal surface resorption • External cervical resorption
mineralized tissue. Damage to the odontoblastic layer • Internal replacement • External replacement
and predentin is a prerequisite for the initiation of resorption resorption (ankylosis)

27 internal root resorption. The advancement of internal • Internal transient apical • External surface resorption
root resorption depends upon bacterial stimulation of breakdown • External transient apical
breakdown
the clastic cells involved in hard tissue response. There

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 Root Resorption 491

The classification and terminology as proposed by

Andreasen is widely acknowledged; however, many
analogous terminologies are also prevalent.

Andreasen terminology Analogous terminology

• Internal inflammatory • Internal root resorption
resorption • Transient surface resorption
• Internal surface resorption • Transient inflammatory
resorption
• External surface resorption • Surface resorption
• External inflammatory • Peripheral inflammatory
resorption resorption
• Periapical replacement
resorption
• External root resorption a b
• External replacement • Progressive inflammatory Fig. 27.3a and b External inflammatory resorption
resorption resorption
• Replacement resorption
• Ankyloses
However, in teeth that have suffered displacement
• Osseous replacement injuries, external root resorption may become extensive.
• External cervical resorption • Invasive cervical resorption
Extrusion or intrusion of teeth, as well as the subsequent
• Hyperplastic tooth resorption repositioning procedures, inevitably lead to denuded
• Odontoclastoma areas on the root surface, which acts as chemotactic to
• Sub-epithelial external root hard tissue-resorbing cells. Root resorption will then
resorption ensue (Fig. 27.4).
Apical root resorption is common in purulent
A. EXTERNAL RESORPTION inflammation and cysts and less common in granulomas;
External resorption involves the lateral/external surface whereas, lateral resorption is observed due to infected
of root, normally covered with cementum and perio- pulp.
dontal ligament. The pathological stimulation which Clinically, such resorption is rapidly progressing and
disturbs the balance between activities of cementoblasts may involve the total surface of roots (Fig. 27.5). The
and osteoclasts, lead to resorption. Minor irritants can tooth show mobility and may be slightly extruded
cause transient resorption, usually reversible after because of inflamed periodontal ligament. Radio-
eliminating the cause; whereas, chronic stimulus lead graphically, a small radiolucency with ragged, irregular
to external resorption. margins is evident.
Clinically, external root resorption is categorized as:
a. External inflammatory resorption (infection related)
b. External cervical resorption
c. External replacement resorption (ankylosis)
d. External surface resorption
e. External transient apical breakdown

a. External Inflammatory Resorption

(Infection Related)
This type of resorption is mainly related to endodontic
infection. Bacteria present in root canals and dentinal
tubules trigger osteoclastic activity on the root surface.
Bacterial toxins, when diffused to periodontal ligament
via exposed dentinal tubules stimulate osteoclastic
activity, leading to resorption of bone and cementum.
Practically all teeth with apical periodontitis will exhibit
apical resorption (Fig. 27.3a and b). Clinically, this condi-
tion is rarely of concern, since after the root canal
treatment the resorption gets resolved or do not progress. Fig. 27.4 External resorption due to displacement
27

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 492 Essentials of Endodontics

Fig. 27.5 External resorption involving almost total surface Fig. 27.6 Cervical resorption

The displacement of the teeth may lead to a disrup- importantly to an area of the cervical root surface
tion of the blood vessels at the apical foramina, (precementum) below the epithelial attachment. The
subsequently ischemic pulp necrosis. Micro-organisms damaged area of the root surface is then colonized by
will ingress into the root canal through enamel-dentin hard tissue-resorbing cells. Predisposing factors may
cracks and exposed dentinal tubules. At this point in include trauma, periodontal treatment, intracoronal
time the root resorption induced by the denuded areas bleaching and associated factors as bruxism, develop-
of the root surface may have exposed tubular root mental defects, etc.
dentin. Bacterial products from the infected root canal Classifying external cervical resorption defects into
will then reach the resorptive lacunae on the root four classes, Heithersay (1999) opined that careful case
surface through the dentinal tubules and sustain the selection is mandatory for achieving successful
resorption of the root. outcome. The classification (Fig. 27.7) is as follows:

Management Class 1: A small invasive resorptive lesion near the

cervical area with shallow penetration into dentin.
Root canal treatment is effective; calcium hydroxide can
be used along with obturating materials [combination Class 2: A well-defined invasive resorptive lesion that
of calcium hydroxide and calcitonin (hormone) inhibits has penetrated close to the coronal pulp chamber, but
clastic activities when placed in the root canal]. shows little or no extension into the radicular dentin.
Acetazolamide, a carbonic anhydrase inhibitor, is Class 3: A deeper invasion of dentin by resorbing tissue,
also used as intracanal medicament to manage root not only involving the coronal dentin, but also extending
resorption (both inflammatory and surface resorption). into the coronal third of the root.
Ledermix paste (combination of antibiotic and steroids) Class 4: A large invasive resorptive process that has
have been effective in controlling external inflammatory extended beyond the coronal third of the root.
root resorption. The classification is useful for assessing the extent
of cervical resorptive defects; however, classification
b. External Cervical Resorption detects lesions on proximal sides only. The lesions on
Cervical resorption (Fig. 27.6) is a kind of external labial/lingual sides are challenging. CBCT can be
inflammatory resorption. It is localized resorptive lesion effective in evaluating these lesions.
of the cervical area of the root below the epithelial
attachment (may not always be in cervical region). Management
Cervical resorption can be associated with vital teeth, Mostly the cervical resorption defects are transient,
a feature which distinguishes it from external inflamma- which means, the cementum repair may occur within
tory resorption (infection is prerequisite). It is seen two to three weeks without any treatment. Treatment,

27 clinically and radiographically as a single resorption

lacuna in the cervical area of the tooth. It appears to
follow injury to the cervical attachment apparatus, most
if necessary, will depend upon severity, location and
whether the defect has perforated the root canal system.
Mainly, the treatment involves removal of resorptive

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 Root Resorption 493

Fig. 27.7 Heithersay classification

lesion and restoring the resultant defect with appro- • Surgical approach may be necessary in some cases
priate filling materials. The objective of the treatment to access resorption area and removal of granulo-
is to arrest resorptive process, restore damaged root matous tissue.
surface and improve esthetics of the tooth. The clinical and radiological signs of external cervical
The treatment protocol involves: resorption are summarized in Table 27.4.
• Smaller lesions (classes 1 and 2) where pulp is not It is important to differentiate external cervical
involved, can be treated by raising the flap and resorption and subgingival caries (Table 27.5).
excavating the defect with appropriate instruments.
The defect can be filled with glass-ionomer cement Table 27.4
Clinical and radiological signs of external cervical
and composite resin. resorption
Heithersay recommended use of topical application Clinical signs Radiological signs
of 90% trichloroacetic acid after curettage of chronic • Cervical area of the tooth • Irregular radiolucency with
resorptive defect, which contains fibro-osseous tissue is involved irregular cervical/proximal
(trichloroacetic acid results in coagulation necrosis • Tooth is generally vital (pulp margins
of the defect without damaging the adjacent involvement in advanced • Advanced lesions may
periodontal tissues). Other solutions, such as 3.0% cases) show mottled appearance
sodium hypochlorite and 17% EDTA have also been • Clinically pink tooth or pink because of fiber-osseous
used. spot is recognized deposition
• Cavity margins are thin and • Intact root canal(s) visible
• Orthodontic extrusion is required in some cases
sharp • Detected accidentally by
where defect is undermined.
• May bleed on probing radiographs
• Root canal treatment may be required in case of class
3 and class 4 defects or any lesion approaching pulp
Differences between external cervical resorption
tissue. Table 27.5
and subgingival caries
• Biodentine can be filled up to occlusal plane, as three- External cervical resorption Subgingival caries
dimensional obturation (MTA has also been tried).
• Present with pink spot • No such spot
• A few authors have suggested dressing of root canals • The base will feel hard; • Sticky on probing
with calcitonin to prevent further progression of scraping sound on probing
resorption [calcitonin, a hormone synthesized by the • Probing will lead to profuse • No such bleeding
thyroid gland (potent inhibitor of clastic cells), inhibits bleeding (underlying highly
osteoclastic activity and also suppress inflammation]. vascular tissue)

27
• Combination of calcitonin and calcium hydroxide as • Positive to pulp testing • May not be positive (depend
upon extent of lesion)
intracanal medicament effectively controls inflamma-
• Cavity has sharp edges • Irregular edges
tory root resorption.

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 494 Essentials of Endodontics

External cervical resorption should also be differen-

tiated from cervical burnout, which usually appears as
a radiolucent band across the entire neck of the tooth.
Three-dimensional imaging with CBCT help assessing
the nature of the lesion.

c. External Replacement Resorption (Ankylosis)

External replacement resorption is the process of
replacement of root surface with bone, termed as
‘ankylosis’. It is not a result of a disease process, but
occurs as a ‘mistake’ because the cells involved in the
remodeling of bone are not able to distinguish between
the dental tissues and bone (common occurrence is
young people, 8–16 years).
The damage to the innermost layer of the periodontal
ligament initiates competitive healing. Healing from the
socket wall (bone marrow-derived cells) and healing
from adjacent periodontal ligament (cementum and Fig. 27.9 Progressive replacement resorption
Sharpey’s fibers) occur simultaneously. If less than 20%
of the root surface is involved, a transient ankylosis may
Clinically, the tooth is immobile, and exhibits a high
occur, which can be resorbed due to functional stimuli,
percussive tone. Radiographically, the periodontal
provided the tooth in that period is stabilized with a
ligament space is absent, and a direct union is seen
splint (transient replacement resorption) (Fig. 27.8). In
between alveolar bone and the root. Total loss of
larger injuries, where 40% or more root is involved, a
cementum and dentin has been seen in few cases,
permanent ankylosis is created (progressive replace-
especially after replantation (Fig. 27.10). Infraocclusion
ment resorption) (Fig. 27.9). The tooth thus becomes
relative to adjacent teeth can be evident both clinically
an integral part of the bone remodeling system; the
and radiographically (ankylosis prevents physiological
resorbing cells remain the osteoclasts. Subsequently,
mesial movement of teeth inhibiting the local growth
osteoblasts replace the resorbed areas of the root with
of alveolar bone, which is sinking into the surrounding
bone.
alveolar ridge).
Bony trabeculae develop within the periodontal
Concurrent internal and external root resorption has
ligament space and fuse to the root surface.
also been reported (Fig. 27.11a and b).

27 Fig. 27.8 Transient replacement resorption Fig. 27.10 Total loss of cementum

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 Root Resorption 495

a b

Fig. 27.11a and b Concurrent external and internal resorption Fig. 27.12 External resorption due to orthodontic pressure

Management ligament space may be missing; a cavity like depression

While appropriate endodontic therapy is effective in can be seen at the site of pressure.
the treatment of external inflammatory resorption, Treatment involves eliminating the cause of the
replacement resorption cannot be arrested or repaired. treatment and rehabilitating the defect with appropriate
Fluoride solution (1.0% stannous fluoride and 2.0% filling material. Rarely, root canal treatment is
sodium fluoride) effectively decrease replacement warranted.
resorption and ankylosis. e. External Transient Apical Breakdown
Ascorbic acid (vitamin C) is effective when applied
Orthodontic application of force over a period of time
in replanted teeth (stimulate osteogenesis by the activa-
may lead to biological changes in periodontal ligament.
tion of alkaline phosphatase, increasing functional
Root resorption associated with orthodontic movement
activity of osteoblasts). Citric acid and phosphoric acid,
pressure frequently occur in maxillary anterior teeth
used earlier, were not effective in controlling resorption.
(Fig. 27.12).
It is hypothesized that in young patient decrowning Transient apical breakdown, a type of root resorption,
is carried out, stimulating the growth of alveolar bone is considered as a temporary process in which apex of
for future implant prosthesis. Even in replanted teeth, a tooth exhibit evidence of resorption radiographically
a layer of fluoride over the roots delays the process of because of orthodontic forces. The teeth respond
ankylosis. normally to pulp tests; radiographically blunting of root
Emdogain, an enamel matrix derivation, has been apices and widening of periodontal ligament may be
successfully employed to restore periodontal ligament, seen. The affected tooth may also display color changes
cementum and alveolar bone in patients with severe (Fig. 27.13a and b).
attachment loss (usual phenomenon in replanted teeth). Genetic factors have also been related to such resorp-
Conditioning of roots with amelogenin (the enamel tion; with many genes such as IL-1B and TNFRSF 11A
protein) in replanted/avulsed teeth stimulates regenera- contributing to the problem.
tion of tooth attachment apparatus. It is recommended No treatment is recommended for transient apical
to take anti-inflammatory drugs to suppress ankylosis. breakdown; the root apex and the surrounding tissues
returns to normal within one year after the removal of
d. External Surface Resorption the forces applied. This type of resorption is to be
External surface resorption is mainly because of chronic distinguished from periapical replacement resorption
mechanical injuries or as a result of continuous pressure without ankylosis (apex of the tooth is involved and
of the impacted teeth, expanding cysts/tumors and do not heal after removal of the cause).
abnormal occlusal contacts. Orthodontic forces also
affect such resorption (Fig. 27.12). External Root Resorption of Non-dental Origin
The location and extent of the defect depends upon
the direction, time of action and the amplitude of the
force applied. Radiographically, the periodontal
Various types of cysts and tumors of the jaws, not of
dental origin, may present signs of external root
resorption. The cysts/tumors causing external root
27

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 496 Essentials of Endodontics

direct and indirect pulp capping and pulpotomy may

lead to internal resorption. Circulatory changes produce
active hyperemia which increase local oxygen tension,
thereby lowering the pH. These collectively alter the
metabolism of the pulp. Vascular changes attract
numerous macrophages which eventually differentiate
into osteoclasts. Multinucleated giant cells are also
described in lacunae next to polymorphonuclear
neutrophils. Finally, the connective tissue may undergo
metaplasia and be changed to granulation tissue.
Clinically, internal resorption is categorized as:
a. Internal inflammatory resorption
b. Internal surface resorption
a b c. Internal replacement resorption
Fig. 27.13a and b Transient apical breakdown d. Internal transient apical breakdown
resorption includes chondrosarcoma, ossifying fibroma, a. Internal Inflammatory Resorption
giant cell reparative granuloma, etc. Such lesions should
Internal inflammatory resorption, also known as ‘Radial
be diagnosed prior to initiating any treatment for root
pulp enlargement resorption’, is characterized by ovoid
resorption. Unnecessary dental treatment should be
or fusiform enlargement of root canal; expansion
avoided and the appropriate surgical/medical treat-
mainly on lateral side. The pulp is chronically inflamed
ment be provided to the patient.
(bacteria may enter pulp tissue via dentinal tubules or
Systemic disorders may also lead to root resorption,
cracks in the cervical root) (Fig. 27.14a and b). Internal
though the frequency is less. Many systemic abnor-
inflammatory resorption is usually asymptomatic and
malities have been associated with root resorption, such
discovered through routine radiographic examination.
as hormonal imbalances, hyperparathyroidism, liver
In rare cases, the resorption may perforate lateral root
and renal diseases, Papillon-Lefèvre syndrome,
surface and appear similar to external resorption. The
osteogenesis imperfecta, etc. These diseases may be
process is analogous to external inflammatory resorption.
diagnosed using blood chemistry tests, Weise analysis,
etc. and should be treated accordingly. b. Internal Surface Resorption
Alendronate is being used to inhibit pathologic Internal surface resorption, also referred to as ‘Transient
osteoclastic-mediated root resorption in systemic root resorption’ (Fig. 27.15), occurs frequently in
diseases (Paget’s disease, osteoporosis and osteoclastic traumatized teeth and in teeth that have undergone
malignancies of bone). A few authors observed that orthodontic and periodontal treatment, but is also seen
Alendronate limited the root resorption, but could not in other teeth, apparently as a result of wear and tear.
impair its occurrence.

B. INTERNAL RESORPTION
Internal resorption involves root dentin and cementum
from within the root canal. It can be apical or intra-
radicular. Radiologically, a small radiolucent area is
seen around the pulp spaces. Internal resorption mainly
affects incisors and mandibular molars. Radiographs
are mandatory for diagnosing internal resorption.
However, sometimes it may manifest clinically as ‘pink
spot’ when resorption progresses to an extent that the
vascular pulpal tissue is seen through the overlying
thinned dental hard tissues. Also, during pulp extirpa-
tion if excessive bleeding occurs clinically, internal

27
resorption should be suspected.
a b
The vascular changes in the pulp subsequent to
trauma, orthodontic tooth movement, chronic pulpitis, Fig. 27.14a and b Internal resorption

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 Root Resorption 497

Fig. 27.15 Transient root resorption Fig. 27.16 Transient apical breakdown

Mineralized or denuded areas of the root surface will material of choice to seal the perforation. Biodentine
attract hard tissue-resorbing cells that will colonize the has also been tried along with thermoplasticized gutta-
damaged areas of the root. However, resorbing cells percha in case of perforation in internal resorption. A
require continuous stimulation during phagocytosis few authors advocate hybrid obturation, whereby
and stimulation by a denuded dentin or cementum apical area is filled with gutta-percha and the resorbed
surface appears to be insufficient to sustain the resorp- area and below is filled with MTA or Biodentine.
tive process for more than 2–3 weeks. A phagocytic Prompt endodontic treatment is imperative in all
colonization of denuded areas of the root, therefore, diagnosed cases of internal root resorption. Calcium
will be transient without additional stimulation of the hydroxide is preferred as sealer along with gutta-
cells, and repair with formation of a cementum-like percha. Calcium hydroxide reduces the inflammatory
tissue will occur both in the root canal and on the root response and initiates prompt healing (because of its
surface. higher pH, it neutralizes the lactic acid produced from
Transient root resorption as such is without clinical macrophages and osteoclasts). It arrests the osteoclastic
importance and the resorption defects are usually too activity and stimulates repair. Success depends upon
small to even be detected radiographically. filling the canal as well as the resorptive defects. As
long as no communication exists with oral fluids (no
c. Internal Replacement Resorption perforation of root canal wall) and the site is covered
Internal replacement resorption is very rare; may occur with epithelial attachment, calcium hydroxide
along with external replacement resorption. The canal treatment is quite successful. However, in case of
spaces may be obliterated with cancellous-like bony perforation, the treatment of choice is surgery, and
tissue. It is hypothesized that dental pulp cells produce filling the defect with appropriate filling material.
osteoid material as a result of reparative mechanism. The distinguishing features of external and internal
A few authors have proposed that cells are non-pulpal resorption are summarized in Table 27.6.
in origin and have migrated into pulp from periapical The management (treatment) protocol of resorption
tissues. is summarized in Table 27.7.

d. Internal Transient Apical Breakdown Internal Root Resorption of Non-dental Origin

The process of internal transient breakdown is Root resorption of non-dental origin is important, since
analogous to external transient breakdown. The apical these type of resorption need medical therapy; whereas,
resorption is caused by orthodontic forces; no treatment conventional endodontic treatment is effective in
is recommended, because the resorption gets healed resorption of dental origin.
once the orthodontic force is removed (Fig. 27.16). Internal resorption caused by herpes zoster infection
is a common occurrence. Herpes zoster (varicella-
Management
In case where the root canal is perforated, mineral
trioxide aggregate (MTA) should be considered the
zoster virus) may impact the trigeminal nerve and
subsequently dental tissues are involved. Oral
complications involve devitalization of teeth along with
27

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 498 Essentials of Endodontics

Table 27.6 Distinguishing features of external resorption and internal resorption

External resorption Internal resorption
• May occur at any surface of root; distribution is not • Mainly within the root surface; distribution is symmetrical
symmetrical
• Ragged/rough margins on the side of defect • Well-demarcated margins; ballooning of root canals
• Radiodensity varies • Radiodensity uniform
• Resorption of bone along with root surface • Resorption confined to root
• Normal root canal shape • Shape of root canal distorted
• No pink spot • Pink spot is a usual sign
• The defect moves away from the canal as the angulation • The defect remain close to canal, even if angulation of
of radiograph changes radiograph changes

Table 27.7 Management protocol of resorption

Type of resorption Surface(s) involved Management
Inflammatory resorption Internal Root canal treatment with calcium hydroxide dressing before placement
(infection related) of root filling. MTA can be filled into the resorption site.
External Root canal treatment with intracanal medication with Ledermix paste or
calcium hydroxide. Once resorption is controlled, root canal can be filled.
Concurrent Root canal treatment with intracanal medication as above.
Surface resorption Internal Monitor radiographically, endodontic treatment only if signs of infection or
(trauma/pressure) discolouration.
External Remove cause (unerupted cuspid, impacted tooth, orthodontic force, cysts
etc.).
In severe cases (e.g. immature tooth in infraocclusion), surgically reposition
and treat root surface with Emdogain, or decoronate and submerge for
future implant therapy.
Replacement Internal If pulp involvement, pulpectomy and root filling after intracanal dressing
(hyperplastic) resorption with Ledermix paste. Orthodontic extrusion if necessary.
External (cervical) Classes 1, 2: Topical application of 90% trichloracetic acid, curettage and
glass ionomer cement restoration.
Class 3: Topical application of 90% trichloracetic acid to resorptive tissue,
curettage, intracanal dressings with Ledermix.
Class 4: Resorptive area filled with MTA/Biodentine and monitor; extraction
and implant placement, if not responding. Surgical intervention may be
required in some cases.
Idiopathic Internal/external Conventional root canal treatment with calcium hydroxide as intracanal
medication.

external/internal resorption. Herpes zoster infection is External cervical resorption may affect multiple
suspected when unexplained dental pain and root teeth, described as ‘multiple idiopathic cervical resorption’
resorption occur in multiple adjacent teeth on one side (MICR). MICR affects number of teeth (minimum three).
of the dental arch. Such lesions are usually asymptomatic. A few authors
Conventional root canal therapy is effective along have linked this resorption to feline herpes virus 1,
with antiviral medication to control further progress
though not documented.
of neuralgia.
Osteosclerotic areas that do not seem to be associated
C. IDIOPATHIC ROOT RESORPTION with infection and/or inflammation are frequently
Idiopathic root resorption of a single or multiple teeth observed on radiographs. These might be part of the
is common in literature. The causative factors may not reparative process or a compensatory response of
unknown cause. There may not be any family history
27 be same as for inflammatory or other types of resorp-
tions. It is assumed that the excessive occlusal loading
may result in dystrophic changes in the periodontium.
or any medical/dental ailment which can be considered
as a possible cause for this type of resorption.

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 Root Resorption 499

Kjaer et al (2012) have reported couple of cases of 13. Heithersay GS. Management of tooth resorption. Aust. Dent.
idiopathic root resorption occurring regionally. The J.: 2007; 52:S105–S121.
authors linked this type of resorption to virus spreading 14. Herrera H. Treatment of external inflammatory root resorption
along nerve path (the resorption process stopped at the after autogenous tooth transplantation: a case report. O. Surg.
area, which might be innervated differently and not O. Med. O. Pathol.: 2006; 102:e51–e54.
infected with virus). They emphasized that neural 15. Jacobovitz M and Lima RKP. Treatment of inflammatory
pattern is important for diagnosis and also for internal root resorption with mineral trioxide aggregate: a
predicting the course of such root resorption. case report. Int. Endod. J.: 2008; 41:905–912.
16. Kaiwar A, Ranjini, MA, Pasha, MF and Meena, N. Internal
Management resorption managed by root canal treatment: Incorporation
There may not be any definite treatment for such teeth; of CT with 3D reconstruction in diagnosis and monitoring of
however, endodontic treatment is beneficial. The teeth the disease. J. Int. Oral Health: 2010; 2:86.
treated with calcium hydroxide and conventional root 17. Kjaer I, Strom C and Worsaae N. Regional aggressive root
canal treatment exhibited evidence of healing. resorption caused by neuronal virus infection. Case Report
in Dent.: 2012; Art. ID 693240.

BIBLIOGRAPHY 18. Krishna R, Ali SN, Pannu D, Peacock ME and Bercowski DL.
An orderly review of dental root resorption. Int. J. Med. Dent.
1. Bergmans L, Cleynenbreugel J, Van Meerbeek, B and Sci.: 2005; 4:669–673.
Lambrechts P. Cervical external root resorption in vital teeth.
X-ray microfocus-tomographical and histopathological case 19. Lad N, Hosey, MT and Hunter KD. Localized idiopathic
study. J. Clin. Periodontol.: 2002; 29:580–585. internal resorption in primary dentition. J. Clin. Pediatr. Dent.:
2010; 34:339–341.
2. Consolaro A. The concept of root resorptions or root
resorptions are not multifactorial, complex, controversial or 20. Maini A, Durning P and Drage N. Resorption: within or
polemical. Dent. Press J. Orthodont.: 2011; 16:1–5. without? The benefit of cone-beam computed tomography
3. Darcey J and Qualtrough A. Resorption: Part 1. Pathology, when diagnosing a case of an internal/external resorption
classification and etiology. Br. Dent. J.: 2013; 214:439–451. defect. Br. Dent. J.: 2008; 204:135–137.

4. Finucane D and Kinirons MJ. External inflammatory and 21. Mohammadi Z, Cehreli ZC, Shalavi S, Giardino L, Palazzi F
replacement resorption of luxated and avulsed replanted and Asgary S. Management of root resorption using chemical
permanent incisors: a review and case presentation. Dent. agents : a review. Iran Endod. J.: 2016; 11:1–7.
Traumatol.: 2003; 19:170–174. 22. Ne RF, Witherspoon DE and Gutmann JL. Tooth resorption.
5. Fishcher WG and Guggenheine J. Concurrent internal and Quint. Int.: 1999; 30:9–25.
external resorption. Oral Surg Oral Med Oral Pathol.: 1977; 23. Nilsson E, Bonte E, Bayet F and Lasfargues JJ. Management
43:161. of internal root resorption on permanent teeth. Int. J. Dent.:
6. Fuss, Tsesis I and Lin S. Root resorption—diagnosis, classifica- 2013; Art. ID 929486.
tion and treatment choices based on stimulation factors. Dent.
24. Panzarini SR, Gulinelli JL, Poi WR, Sonoda CK, Pedrini D
Traumatol.: 2003; 19:175–182.
and Brandini DA. Treatment of root surface in delayed tooth
7. Gonzalez OL, Vera J, Orozco MS, Mancera JT, Gonzalez KV replantation: a review of literature. Dent. Traumatol.: 2008;
and Malagon GV. Transient apical breakdown and its 24:277–282.
relationship with orthodontic forces: a case report. J. Endod.:
2014; 40:1265–1267. 25. Patel S and Pitt Ford TR. Is the resorption external or internal?
Dent. Update: 2010; 34:218–229.
8. Goultschn J, Nitzan D and Azaz B. Root resorption: review
and discussion. Oral Surg. Oral Med. Oral Pathol.: 1982; 26. Patel S, Kanagasingham S and Pitt Ford T. External cervical
54:586–591. resorption: a review. J. Endod.: 2009; 35:616–625.
9. Gunraj MN. Dental root resorption. Oral Surg. Oral Med. 27. Patel S, Ricucci D and Tay F. Internal Root Resorption: A
Oral Pathol. Oral Radiol.: 1999; 88:647–653. Review. J. Endod.: 2010; 36:1107–1121.
10. Haapasalo M and Endal U. Internal inflammatory root 28. Rajasekharan S, Martens LC, Cauwels RG and Verbeeck RM.
resorption: the unknown resorption of the tooth. Endod. Biodentine material characteristics and clinical applications:
Topics: 2006; 14:60–79. a review of the literature. Eur. Arch. Paediatr. Dent.: 2014;
11. Harokopakis-Hajishengallis E. Physiologic root resorption in 15:147–158.
primary teeth: molecular and histological events. J. Oral Sci.: 29. Re D, Ceci C, Cerutti F, Del Fabbro M, Corbella S and
2007; 49:1–12.
12. Heithersay GS. Invasive cervical resorption. Endodontic
Topics: 2004; 7:73–92.
Taschieri S. Natural tooth preservation versus extraction and
implant placement: patient preferences and analysis of the
willingness to pay. Br. Dent. J.: 2017; 222:467–471.
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30. Sak M, Radecka M, Karpinski TM, Wedrychowicz-Welman 36. Stamos DE and Stamos DG. A new treatment modality for
A and Szkaradkiewicz AK. Tooth root resorption: internal resorption. J. Endod.: 1986; 12:315–319.
etiopathogenis and classification. MicroMedicine: 2016;
4:21–31. 37. Thomas P, Pillai RK, Ramakrishnan BP and Palani J. An insight
into internal resorption. ISRN Dent.: 2014; Art. ID 759326.
31. Samir PV, Dhull KS, Dutta B, Bachi A and Verma T. Invasive
cervical resorption: An insidious form of external root 38. Tronstad L. Root resorption—etiology, terminology and
resorption. IOSR J. Dent. Med. Sci.:2017; 16:24–32. clinical manifestations. Endod. Dent. Traumatol.: 1988; 4:
32. Santos BO, Mendonca DS, de Sousa DL, Neto JJ and Araujo 241–252.
RB. Root resorption after dental traumas: classification and 39. Umashetty G, Hoshing U, Patil S and Ajgaonkar N.
clinical, radiographic and histologic aspects. RSBO: 2011; Management of inflammatory internal root resorption with
8:439–445.
biodentine and thermoplasticised gutta-percha. Case Report
33. Sikri VK. Root resorption—An enigma. IJCDC: 2011; in Dent.: 2015; Art. ID 452609.
1:11–15.
40. Vatanpour M, Javidi M, Zarel M and Shirazian S. External
34. Sogur E, Sogur HK, Baksi BG and Sen BH. Idiopathic root
root resorption: Arrested or progressing?. Int. Endod. J.: 2008;
resorption of the entire permanent dentition: systemic review
41:997–1004.
and report of a case. Dent. Traumatol.: 2008; 24:490–495.
35. Solzano S and Tirone F. Mini-invasive non-surgical treatment 41. Vier FV and Figueiredo JA. Internal apical resorption and its
of class 4 invasive cervical resorption: a case series. Giornale correlation with the type of apical lesion. Int. Endod. J.: 2004;
Italiano di Endodonzia: 2016; 30:52–63. 37:730–737.

27

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 Chapter
28
Pediatric Endodontics

The importance of retaining deciduous teeth in the long- teeth, due to the presence of accessory canals in the
term prognosis of maintaining the arch is gaining thin floor of the pulp chamber).
significance over the years. The root canal treatment in • The crowns of anterior primary teeth have prominent
primary teeth is to be planned keeping in mind the facial and lingual cervical thirds of crown.
remaining teeth, age of the child and also the probable • The primary teeth exhibit marked constriction at
effects of early extraction. cementum-enamel junction (cervical portion of
Extensive dental decay in the primary dentition, that crown); the area susceptible to perforate.
easily progresses to the dental pulp (dentin thinner than
permanent teeth), remains a serious problem in b. Differences in Root Formation
pediatric dental practice. The first treatment decision • Primary teeth have characteristic ribbon-like
for the young patient with one or more grossly carious radicular pulp, i.e. narrower and longer roots as
primary teeth is whether to retain or to extract. Root compared to permanent teeth. In addition, their root-
canal treatment is the treatment of choice to retain them; to-crown length is greater than permanent.
however, it should be carried out after evaluating
• Molar roots flare out from cervix to the apex to
patient’s existing dentition (age and strategic
accommodate permanent tooth crowns (care to be
importance of developing teeth) and also the associated
taken while cleaning and shaping).
clinical implications. The basic aims and treatment
• In permanent teeth, root length is not completed until
protocol of endodontic therapy in children are the same
1–4 years after a tooth erupts into oral cavity;
as those in adults; however, certain areas need special
whereas, in primary teeth it is completed in a short
consideration in deciduous and young permanent teeth.
period of time because of shorter length of the
primary roots.
DIFFERENCES IN PRIMARY AND PERMANENT TEETH
• Root resorption and deposition of additional dentin
a. Difference in Morphology within the root canal system may change number,
• The primary teeth are smaller in dimensions than size and shape of the root canals within the primary
their permanent counterparts. Their crowns are tooth.
wider mesiodistally than cervico-occlusal length (key • The primary tooth root will begin to resorb as soon
feature during access opening). as the root length is completed. The resorption
• The enamel in primary teeth is thinner with continually changes the position of the apical fora-
consistent depth. The thickness of dentin between men; no such phenomena in permanent teeth (care
the pulp chambers and enamel in primary teeth is to be taken while cleaning, shaping and obturation).
less. Primary molars have larger pulp chambers with
higher pulp horns, especially the mesial. The c. Differences in Root Canals
advancing carious lesions may involve pulp of • The root canals of anterior primary teeth are
primary teeth far earlier than permanent teeth. relatively simple, have few irregularities, and can be
• The primary teeth have thin pulpal floor as compared easily managed; whereas, the posterior primary teeth
to permanent teeth (periradicular lesions associated may have ramifications and deltas between canals,
with infected primary molars are usually inter- making debridement difficult and subsequently
radicular rather than periapical as in permanent success of the treatment.

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 502 Essentials of Endodontics

• The maxillary primary molars may have two to five

canals, with the palatal root usually rounder and
longer than the two buccal roots. The primary
mandibular first and second molars usually have
three canals which generally correspond to the
external root canal anatomy.
The general features of deciduous tooth are depicted
in Fig. 28.1.
Variations in Root and Root Canal Morphology of
Deciduous Teeth
The root and root canal morphology of deciduous teeth,
especially molars show wide anatomical variations
(aberrant internal anatomy might be attributed to secon- Fig. 28.2a Radix entomolaris
dary dentin formation and physiologic root resorption,
• Usually maxillary molars present ovoid-shaped
which are able to reconfigure the root canal system).
canal; whereas, mandibular molars may present with
• Two rooted maxillary first molars have been reported
ovoid-shaped and ribbon-shaped canal outlines (75%
in approximately 50% cases.
molars have consistent cross-sectional root canal
• Two rooted second maxillary molars have been outline from cervical to apical area).
observed to be 10%.
• Three canals in maxillary canine (Fig. 28.2b to e); a
• Mandibular first molars are mostly two rooted. less documented case.
• Mandibular second molars may be three-rooted in • The complex pulp and periodontal tissues inter-
30% cases. relationship in primary molars may result in
• Maxillary first molar usually exhibit one canal in one appearance of radiolucency anywhere along the root
root; 10% cases may have two root canals in mesio- or in the furcation area.
buccal root (five and six root canals in three roots
have also been reported).
• Number of root canals in maxillary second molar are
usually similar to first molar.
• Mostly mandibular first and second molars exhibit
canals in two roots (four and five canals have also
been reported).
• Radix entomolaris is also seen in deciduous first
molar (Fig. 28.2a).
b c

28 Fig. 28.1 Features of deciduous tooth

d e

Fig. 28.2b to e Primary maxillary canine (three root canals)

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 Pediatric Endodontics 503

• Radicular resorption of the deciduous tooth may help us evaluate the condition of the pulp chamber and
create pulpal-periodontal communications in areas the root canals, the status of the furcal area, periapical
other than the apical foramen. area and the surrounding bone. Intraoral radiographs
Rimondini and Baroni (1995) studied 80 primary are usually not possible due to poor cooperation of the
molars in children 4 to 12 years old, 75 of which were children; alternative methods can be preferred.
extracted because of pulpal involvement. The teeth Interpretation of radiographs is usually complicated
were measured and the apices and areas of resorption in children. The superimposition of the furcation of the
were located. maxillary molars on the palatal root makes accurate
reading difficult in maxillary molars. In addition, young
They observed as follows:
permanent teeth with incompletely formed roots also
• Roots that were longer than 10 mm were related to a pose a problem. The factors which complicate the
curved root shape with no external resorption. interpretation of radiographs are, large bone narrow
• Roots with length between 4.0 mm and 7.0 mm were spaces, superimposition of developing tooth buds and
associated with advanced root resorption. normal resorption of deciduous roots.
• Roots that were shorter than 4.0 mm were associated
d. Pulp vitality tests
with resorption and perforation at the furcation.
Pulp testing in children is usually unreliable because
The authors were of the view that resorption up to children usually do not cooperate. The incomplete
4.0 mm length of a root can be successfully treated. innervations of newly erupted teeth may also affect the
results. In addition, each test is subjective that depends
DIAGNOSIS on patient’s perceived response to a stimulus as well
Diagnosis of pulp involvement in deciduous teeth as as the operator’s interpretation. The validity of
well as in young permanent teeth present difficulties children’s response in pulp vitality testing has always
due to rapid spread of inflammation in the coronal and been questioned (may elicit false positive or false
radicular pulp. Early stages may not indicate the extent negative results).
of tissue damage; even pain is felt when periradicular i. Traditional methods: The traditional methods of pulp
tissues are involved. vitality testing like electric pulp test, thermal pulp
The clinical diagnosis may be derived from the test, anesthetic test, preparing a test cavity, etc. are
following. based on stimulation of nerve fibers and may not
be accurate. The use of traditional tests help
a. Medical and dental history
establish an empirical diagnosis; may not be
Children usually do not give accurate details of their
accurate and reliable.
symptoms; parents should be involved in noting the
ii. Newer tests: The blood circulation is considered as
history. Systemic illness is not usually a contra-
the accurate way of assessing pulp vitality. The
indication for root canal therapy in primary teeth,
blood supply of the pulp is evaluated through light
except in severe cases like congenital heart disease. Root
absorption and reflection (photoplethysmography,
canal therapy is the treatment of choice in hemophiliacs.
pulse oximetry and dual wavelength spectrophoto-
Pre-treatment and post-treatment antibiotic coverage
metry) or the shift in light frequency as it is reflected
is indicated for most of the systemic conditions. The
back from a tooth (laser Doppler flowmetry). They
past dental treatment, including current symptoms
offer the advantages of being objective, non-invasive
coupled with chief complaints should be noted and
and atraumatic and are accurate and reliable.
evaluated before proceeding to endodontic treatment.
e. Color and amount of blood at the exposure site
b. Clinical examination
The color and amount of blood at the exposure site may
A careful extraoral and intraoral examination will pre-
be a reliable guide as regards pulpal inflammation in
sent an overview of the general conditions of teeth and
primary teeth. Light-red blood and hemorrhage that
the surrounding tissues. Palpation and percussion are
can be arrested easily is limited to the coronal pulp.
considered helpful diagnostic tools; however, they
Profuse hemorrhage from the exposure site, with deep-
are not reliable in children due to the psychologic aspects.
red blood, is associated with inflammation extending
c. Radiographs into the root canals. The former is indicated for
pulpotomy while the latter would require pulpectomy.
Radiographs are essential prior to the commencement
of treatment, though it may not provide adequate
information of early pathological changes. Radiographs
The diagnostic features for pulp status in deciduous
teeth is tabulated in Table 28.1.
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Table 28.1 Diagnostic features for pulp status in deciduous teeth

Diagnostic features Pulp condition
Reversible pulpitis Irreversible pulpitis Pulp necrosis
Mobility No May be mobile May be mobile
Tender on percussion No Yes Mostly
Widening of periodontal ligament No Often Yes
Excessive bleeding at the pulp stumps No Often No
Swelling No Rare May be present

PULP THERAPY The treatment modalities of pulp therapy are:

Pulp therapy in primary teeth is aimed at retaining the I. Indirect pulp capping/treatment
tooth in a symptom-free state until it is lost naturally II. Direct pulp capping
during the transition from primary to permanent III. Pulp curettage
dentition. IV. Pulpotomy/cervical pulpotomy/complete pulpo-
tomy
Goals
V. Non-vital pulpotomy
• To retain the tooth in the oral cavity in a non- VI. Partial pulpectomy
pathological state
VII. Pulpectomy
• Maintenance of the arch length and tooth space VIII. Apexification/Apexogenesis
• To restore the tooth to its function and form
• To prevent possible deviation of speech I. Indirect Pulp Treatment/Capping
• Preventing psychological trauma to the child The procedure involves removal of gross caries
followed by sealing rest of the cavity with an appro-
Indications priate bactericidal/obtundant agent.
i. General Indirect pulp treatment is a technique in which an effort
• Cooperative child is made to avoid pulp exposure during the treatment
• Child with blood dyscrasias or bleeding abnormality of teeth with deep carious lesions, without any evidence
(e.g. hemophilia) for whom extraction is not advisable of pulp involvement. All the carious dentin is removed,
leaving a thin non-carious dentin, which is then covered
ii. Dental
with calcium hydroxide or any other suitable materials.
• The patient exhibiting sign and symptoms of pulpitis
Indirect pulp capping involves excavating deep caries
• Loss of interproximal marginal ridge, due to progress
and the deeper layers of softened dentin is covered with
of caries.
a pulp capping agent. After a period of 6–8 weeks, the
• Radiographic evidence of caries extending more than tooth is reopened, and the remaining soft caries, if any,
half way from the dentinoenamel junction to the is removed (technique is no longer recommended). It
pulp. has been established that all caries is to be removed,
• Primary tooth need to be retained due to absence of even in case of exposure; direct pulp capping or
its permanent successor. pulpotomy procedure is recommended in case of pulp
exposure.
Contraindications
i. General Objectives
• Uncooperative child • To arrest the carious process and provide conditions
• A child with congenital heart disease or a history of conducive to the formation of reactionary dentin and
rheumatic fever. remineralization of remaining carious dentin.
• To preserve the vitality of pulp tissues
ii. Dental
• To promote pulpal healing and dentinal sclerosis
• Tooth, which cannot be restored
• Caries penetrating sub-pulpal floor of the pulp chamber Indications

28 • A tooth close to natural exfoliation (i.e. less than two-

thirds of root length remaining)
• Extensive pathological root resorption in a tooth
Indirect pulp capping treatment is indicated when:
• History of mild discomfort from chemical and
thermal stimuli with the absence of spontaneous pain.

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 Pediatric Endodontics 505

• Clinically, the tooth should reveal a large carious treatment has been quite successful in primary teeth.
lesion in close proximity to the pulp without any Healing of the pulp can be confirmed by the formation
signs or symptoms of pulp involvement. Radio- of reparative dentin under the affected tubules. Follow-
graphic examination should exhibit normal lamina up of teeth receiving vital pulp therapy is very
dura and periodontal ligament space with no inter- important. The follow-up radiographs should be
radicular or periapical radiolucency. compared with the preoperative radiographs to
• In case of minimal pulpal inflammation (for example, observe any change. No change between the pre-
reversible pulpitis), complete removal of caries may operative and follow-up radiograph is the standard for
lead to a pulp exposure. success.
Contraindications
Should Calcium Hydroxide be
• Any signs of pulpal/periapical pathology
used in Deciduous Teeth?
• Soft dentin covering large area of the cavity
• Swelling/fistula It is established that calcium hydroxide, when placed
• Tenderness to percussion in permanent teeth, results in calcific (dentin) bridge
• External/internal root resorption formation. It is hypothesized that certain properties of
• Periapical/inter-radicular radiolucency calcium hydroxide that produces healing in permanent
teeth, may provoke untoward reactions in the pulps of
It is established that carious dentin consists of two primary teeth. These intense inflammatory responses
distinct layers having different ultramicroscopic and to calcium hydroxide in deciduous teeth may trigger
chemical structures. macrophages to fuse and transform into odontoclasts;
• Infected dentin: The outer carious layer, which is subsequently leading to root resorption. Though the
irreversibly denatured and incapable of being re- exact mechanism of such odontoblastic activity is not
mineralized should be removed (contains significant clear, various hypothesis have been proposed, such as:
number of bacteria).
• Calcium hydroxide-induced resorption in deciduous
• Affected dentin: The inner carious layer, which is
teeth may be attributed to inflammatory cytokines,
reversibly denatured, not infected (with no
which contribute to transformation of preodonto-
demonstrable bacteria) and capable of being re-
mineralized should be preserved. clasts to odontoclasts.
The clinical challenge in indirect pulp treatment is • The high pH of calcium hydroxide has beneficial
the assessment of how much caries should be kept at effects, viz. neutralization of acid products, anti-
pulpal/axial floor. Whether an area is an infected microbial property, and the activation of alkaline
phosphatase. When calcium hydroxide is placed in
carious lesion or a bacteria-free demineralized zone is
deciduous teeth, it is hypothesized that the high
the quality of the dentin; soft, mushy infected dentin
alkaline pH could trigger existing preodontoclasts
should be removed without exposing pulp, and hard
(undifferentiated mesenchymal cells) to transform
discolored affected dentin can be indirectly capped.
into odontoclasts.
These two layers can be differentiated clinically by
• It has been established that resorption can occur
caries detector dyes. It can help in determining the
when the protective un-mineralized tissues such as
extent of outer infected layers of caries.
pre-cementum and pre-dentin are mechanically
Step-wise caries removal, also known as interim damaged, allowing osteoclasts/odontoclasts to gain
restorative treatment, implies removal of caries with access to calcified dental tissues. It is known that the
hand instruments in steps. Various authors have placement of calcium hydroxide produces a super-
concluded that in deep lesions, partial caries removal ficial zone of necrosis because of its high alkalinity.
is preferable to complete caries removal to minimize This could also cause damage to the pre-dentin,
the risk of carious exposure. which may lead to exposure of the underlying dentin
Various materials, calcium hydroxide, mineral to resting odontoclasts. These odontoclasts, after
trioxide aggregate (MTA) and glass-ionomer cement being activated, result in tooth resorption.
have been used in indirect pulp capping.
The indirect pulp treatment is considered as the most II. Direct Pulp Capping
appropriate treatment for symptom-free primary teeth
with deep caries provided the cavity is filled with
leakage-resistant restoration. The indirect pulp
Direct pulp capping is defined as ‘the placement of a
medicated/non-medicated material on the pulp that has been
exposed while excavating the last portions of caries or as a
28

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 506 Essentials of Endodontics

result of trauma’. The objective of direct pulp capping is • Preserving the radicular pulp in a healthy state
to encourage the formation of a dentin bridge at the • Rendering the radicular pulp inert
point of pulp exposure with preservation of pulpal • Encouraging tissue regeneration and healing at the
health and vitality, and to seal the pulp against bacterial site of radicular pulp amputation
leakage. Pulp capping procedures in primary teeth
should be reserved for teeth with small mechanical or Indications
traumatic exposures or in cases in which the teeth will • A carious or mechanical exposure of vital coronal pulp
exfoliate within 1 or 2 years. It is hypothesized that the • Aggressive progress of carious lesion
high cellular content of primary pulp tissue may be • Tooth free of radicular pulpitis (elicited by hemorr-
responsible for the failure of direct pulp capping in hage from amputation site)
primary teeth. Undifferentiated mesenchymal cells may • At least two-thirds of the primary tooth root is still
differentiate into osteoclastic cells in response to either present
the caries or direct pulp capping which could lead to • Asymptomatic tooth or only transient pain
internal resorption. Direct pulp capping has limited • Where extraction of the primary tooth is contra-
application and is not recommended for deciduous indicated
teeth.
Contraindications
Pulp capping: Key features • Tooth which cannot be restored
• Avoid exposing the pulp; tooth can survive even if residual • History of spontaneous pain/pain on percussion
caries remain. • Presence of an abscess
• Calcium hydroxide is the material of choice; MTA is equally
• Permanent successor close to eruption
effective.
• Zinc oxide eugenol, glass ionomers and adhesives are poor
• Presence of necrotic pulpal tissue/suppuration from
pulp capping agents. the root canal
• The rest of the cavity is to be filled with leakage-resistant • If hemorrhage from pulpal tissue is uncontrollable
restoration.
• In case pulp is exposed, control haemorrhage with sodium
Pulpotomy procedure is categorized as single-visit or
hypochlorite (possess antibacterial properties). two-visit pulpotomy
A. Single-visit pulpotomy
III. Pulp Curettage B. Two-visit pulpotomy
It is a modification of the direct capping technique, a. Desensitizing pulpotomy
wherein the exposure site is enlarged prior to the place- b. Devitalization pulpotomy
ment of capping material. Exposure site enlargement i. Devitalization using paraformaldehyde
serves three purposes: ii. Devitalization using formocresol (formocresol
• Removes inflamed and/or infected tissue in the pulpotomy)
exposed area. c. Preservative pulpotomy
• Facilitates removal of carious and non-carious debris d. Regenerative (inductive/reparative) pulpotomy
particularly dentin chips.
• Ensures intimate contact of the capping material with A. Single-visit Pulpotomy
healthy pulp tissue. The concerned tooth is anesthetized and isolated. The
The location of exposure is important as there should pulp chamber is opened using appropriate armamen-
be no pulp tissue coronal to the exposure. Exposure in tarium and the roof of the pulp chamber is removed
a cervical cavity would lead to reactionary dentin carefully. The inflamed pulp from the coronal chamber
formation, which would restrict the blood supply to the is removed using sterilized excavators. The exposed site
tissue more coronal to it, leading to necrosis and failure. is disinfected with formocresol and covered with
These teeth should preferably be root canal treated. calcium hydroxide, followed by restoring the tooth with
appropriate restorative material.
IV. Pulpotomy/Cervical Pulpotomy/
Complete Pulpotomy B. Two-visit Pulpotomy
Pulpotomy procedure in primary teeth is defined as a. Desensitizing pulpotomy

28 ‘amputation of the affected or infected coronal portion of the

dental pulp, preserving the vitality and function of the remaining
radicular pulp’. The main approaches to this technique are:
Desensitizing pulpotomy is carried out to reduce pulpal
inflammation, in order to facilitate subsequent
pulpotomy or pulpectomy procedure.

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 Pediatric Endodontics 507

Indications • Hyperalgesic pulp (adequate analgesia not achieved).

• Hyperalgesic pulp (adequate analgesia not achieved) i. Devitalization using paraformaldehyde [Paraformal-
• Carious pulp exposure with no signs/symptoms of dehyde paste, camphorated paramonochloro-
loss of vitality phenol (CMCP) and Cresol etc. are used to
• Non-compliant child devitalize the coronal part of the pulp]. The
constituents of Paraformaldehyde pastes are:
Procedure paraformaldehyde (l.0 g), lignocaine (0.06 g),
Tooth is anesthetized and isolated. Caries is removed carmine (10 mg), carbowax 1500 (1.3 g), and
and a small pledget of cotton wool loaded with steroid- propylene glycol (0.5 ml).
antibiotic paste (Ledermix, Septomix) is placed directly Procedure
over exposure site (tooth is usually too sensitive to remove First visit: After gaining access to the pulpal exposure
entire roof of pulp chamber). A temporary dressing is area, a pledget of cotton wool soaked with small
placed over the cotton pledget. After 6–8 weeks recall, amount of paraformaldehyde devitalizing paste is
the operator may proceed with a pulpotomy or applied to the exposed pulp tissue. Formaldehyde
pulpectomy technique, depending on clinical findings. vapor liberated from the dressing permeates
b. Devitalization pulpotomy through the pulpal space causing fixation of the
Devitalization implies ‘mummifying’ the pulp tissue. tissues. A layer of zinc oxide-eugenol is placed
The term ‘mummified’ has been described to chemically passively without applying pressure. The patient
treat pulp tissue that is inert, sterilized, metabolically must be informed of possibility of mild discomfort.
suppressed, and incapable of autolysis. This two-stage Second visit: After a couple of weeks, the devitalized
procedure mummifies and fixes the coronal pulp tissue, coronal pulp may be removed, without the need
while the major part of the radicular pulp may remain for local anesthesia. Zinc oxide-eugenol mixed with
vital. formocresol is then placed over the radicular
stumps and the tooth is restored with appropriate
Indications material (Fig. 28.3a to d). If vital tissues remain in
• Inability to arrest hemorrhage from the amputated the coronal pulp chamber, a further dressing of
pulp stumps during a single-visit pulpotomy. paraformaldehyde paste can be applied.

a b

c d

Fig. 28.3a to d Pulpotomy (first deciduous molar)

28

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 508 Essentials of Endodontics

ii. Devitalization using formocresol (formocresol pulpotomy): c. Preservative pulpotomy

Formocresol is the standard medicament in both Preservative pulpotomy involves medicaments and
vital and non-vital pulp therapy techniques in the techniques that provide minimal insult, maintain the
primary dentition. Despite its potential risks it vitality and normal histologic appearance of the entire
continues to be one of the treatment choices for radicular pulp.
primary teeth. The medicaments commonly used in preservative
Buckley’s formocresol solution consists of 35% pulpotomy are:
tricresol, 19% aqueous formaldehyde, glycerine, i. Glutaraldehyde: Application of 2.0–4.0% glutaral-
and water. A 1:5 dilution of Buckley’s formocresol dehyde produces rapid surface fixation of the under-
is recommended as the pulp medicament, as it is lying pulp tissue; however, its depth of penetration is
less damaging. limited.
The histologic studies on formocresol pulpotomy Advantages of glutaraldehyde over formocresol
have shown distinct zones in the pulp as follows: • It has mild effects on pulp tissue and does not perfuse
• Superficial debris along with dentinal chips at into the pulp tissue to the apex; demonstrate less
the amputation site systemic distribution immediately after its applica-
• Eosinophil-stained and compressed tissue tion.
• A pale stained zone with loss of cellularity • Large dose caused little toxic effects.
• An area of fibrotic and inflammatory activity • Provides superior fixation with relatively little
• An area of normal-appearing pulp tissue immunogenicity.
considered to be vital. • Exhibits very low tissue binding and is readily
Earlier investigators have used 5.0% sodium metabolized mostly in the kidneys, lungs, liver, heart
hypochlorite as a pulpotomy agent in primary and muscle tissues and is eliminated in urine.
molars. The success rate of sodium hypochlorite is Histologic features
comparable to formocresol and ferric sulphate • Less damage/necrosis of apical tissue.
pulpotomies. • Clearly demarcated zones within radicular tissue are
Toxicity minimum.
Formocresol has demonstrated high clinical and • Absence of multizones in the root pulp (a homo-
radiographic success; however, this medicament genous, eosinophilic stained zone may be present
may exhibit certain potential risks. The concerns below amputated surface).
over use of formocresol are tabulated in Table 28.2. • No evidence of ingrowth of granulation tissue.
The International Agency for Research on Cancer • Less dystrophic calcification and limited to coronal
(IARC) has documented that there was sufficient portion of canal.
evidence that formaldehyde might cause • Fibroblastic proliferation is observed immediately
nasopharyngeal cancer in humans. Studies linking below glutaraldehyde fixed tissue in coronal 3rd
formocresol with nasopharyngeal cancer are based
indicating repair/replacement.
on chronic exposure to formaldehyde (both humans
and animals) at very high doses. There is also Limitations
evidence of a causal relationship between • Neither the optimum concentration of glutaral-
formaldehyde exposure and leukemia. dehyde nor the amount of time of application has
been established.
Table 28.2 Concerns over use of formocresol • It has lower clinical success rate than with formocresol.
• It is caustic and toxic at high doses (It is no longer preferred concerning about the handling
• Histologically, pulp responds with inflammation and necrosis of glutaraldehyde and its hypersensitivity.)
• Potential systemic absorption and distribution throughout the ii. Hemostatic agents: The commonly used hemostatic
body; may lead to liver and kidney changes agents are:
• May effect the enamel of succedaneous teeth • 20% ferric sulphate (Monsel solution)
• Possibility of reversible fixation leading to autoantibody • 1.0% feracrylum solution (Repalum)
formation
• Mutagenicity and carcinogenicity
Procedure

28 • Destruction of cellular integrity due to cresol

• May lead to nasopharyngeal cancer and leukemia
Hemostatic agents are available in solution form along
with an applicator tip. Following hemorrhage control,
ferric sulphate (commonly used hemostatic agent) is

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 Pediatric Endodontics 509

gently applied to the pulp stumps for 10–15 seconds (it • Nd:YAG laser: The successful effects of Nd:YAG laser
requires only 15 second for manipulation as compared on the wound healing of amputated pulps has been
to 5 minutes for formocresol.) The pulp chamber should established.
then be gently rinsed with water and dried with cotton • Er:YAG laser: Er:YAG laser has been successfully used
pellets. A thick mix of zinc oxide eugenol is placed in in treating both vital and non-vital primary teeth.
the chamber and tightly packed against the pulp • Argon laser: Argon laser pulpotomy for primary teeth
stumps. A few authors have cautioned, fearing that the has shown formation of reparative dentin.
eugenol may promote internal resorption following the
ferric sulphate pulpotomy. d. Regenerative pulpotomy
Ferric sulphate prevents problems arising from clot Regenerative pulpotomy implies use of agents that have
formation after the removal of the coronal pulp. It also cell-inductive capacity to replace lost cells or induce
minimizes the chances of inflammation and internal existent cells to differentiate into hard tissue-forming
resorption, an important factor for the failure of elements.
pulpotomy with calcium hydroxide. Calcium hydroxide was the first medicament to be used
Ferric sulphate is preferred instead of formocresol in a ‘regenerative capacity’ because of its ability to
for pulpotomy of primary teeth. It has shown significant stimulate hard tissue barrier formation. Calcium
clinical and radiological success over a period of three hydroxide stimulates dentin bridge formation, leading
years. to healing of pulp tissue. Its regenerative capacity has
been questioned owing to the fact that its response is
iii. Electrosurgery: Electrosurgery is a non-pharmaco- more reactive than inductive.
logical hemostatic pulpotomy for primary molars; a A high failure rate using calcium hydroxide for
non-chemical devitalization approach. pulpotomy in primary teeth has been demonstrated,
It carbonizes and denatures superficial pulp tissue which is explained by the presence of an extrapulpal
producing a layer of coagulation necrosis. It provides clot separating the calcium hydroxide from the pulpal
a barrier between healthy radicular tissue and any base tissue and thus impairing healing.
material placed in the pulp chamber. The odontoblasts It is established that use of calcium hydroxide lead
are stimulated to form a dentin bridge and the tooth is to internal root resorption, which might result from
maintained in the arch with vital radicular tissue until overstimulation of the primary pulp by its highly
it exfoliates. alkaline nature. This alkaline-induced overstimulation
Procedure could cause metaplasia within the pulp tissue, leading
The procedure is basically the same as for the to the formation of odontoclasts.
formocresol technique. Following removal of coronal In addition, undetected microleakage could allow
pulp tissue, a sterile cotton pellet is placed in contact large numbers of bacteria to cover the pulp and nullify
with the pulp, and pressure is applied to obtain the beneficial effects of calcium hydroxide.
hemostasis. A dental electrode is used to deliver the Mineral trioxide aggregate (MTA) allows for bone
electrical arc. The cotton pellet is quickly removed, and regeneration and overgrowth of cementum when used
the electrode is placed 1.0–2.0 mm above the pulp as a root-end filling material. It is biocompatible
stump. The electrical arc is allowed to bridge the gap material, with sealing ability superior to amalgam and
at the pulp stump for one second, followed by cooling zinc oxide eugenol. It has many positive properties such
for five seconds. The pulp stumps appear dry and as alkaline pH, radiopacity, high sealing capacity and
completely blackened after the procedure. Zinc oxide ability to induce the formation of dentin, cementum
eugenol is placed directly over the pulp stumps filling and bone.
the pulp chamber. The true cell-inductive agents include transforming
growth factor-β (TGF-β) in the form of bone morpho-
iv. Lasers: Lasers are an effective alternative for treating genetic proteins, and Freeze-dried bone. These materials
pulps, as no chemical is being introduced into the young are also being tried in pulpotomy of primary teeth.
canals.
Lasers used in pulpotomy are: Failures of pulpotomy
• Carbon dioxide laser: The advantage of carbon dioxide • The first sign of failure is often internal resorption;
laser over other lasers is that the bloodless tissue subsequently, external resorption may occur
incisions can be attained at a practical cutting speed
and also the edges of the irradiated tissue are covered
by only a thin layer of necrotic material.
• Pulp canal obliteration can be seen
• Radiolucency might develop at the bifurcation and
trifurcation area
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 510 Essentials of Endodontics

• Presence of fistula/excessive mobility of operated

tooth
• Inflammatory follicular cysts may develop

V. Non-vital Pulpotomy
Non-vital pulpotomy is technically a misnomer. It is
followed when root canal treatment is to be delayed
for some reasons.
a b
Indications Fig. 28.4a and b Partial pulpectomy
• When the inflammatory process affecting the coronal
pulp has extended to the radicular pulp leading to After successful hemorrhage control, a formocresol
irreversible changes in the pulp tissue dampened cotton pellet, squeezed dry, is placed in the
• When the pulp is non-vital, along with periradicular pulp chamber for a day or so.
involvement The pellet is removed, and zinc oxide eugenol cement
• Where pulpectomy is to be delayed for some reasons is packed with gentle pressure.
The tooth is restored in routine after 6–8 weeks
Procedure follow-up of the procedure (permanent restoration is
At the first visit, the necrotic contents of the pulp are usually delayed, since partial pulpectomy is for short
removed and the infected radicular pulp is treated duration; subsequently, pulpectomy is to be carried
with beechwood creosote solution [composition: D- out).
methoxyphenol (47%), p-methoxyphenol (26%), cresol
(13%), m-methoxyphenol (7%) and incipients (7%)]. In VII. Pulpectomy
the next visit, the tooth is checked for any adverse signs
Pulpectomy can be defined as ‘removal of the inflamed/
and symptoms. If there is evidence of infection (sinus,
pain, swelling, etc.), beechwood creosote dressing necrotic pulp, cleaning and shaping the root canals, and
should be placed. If symptoms have resolved, the tooth obturation of the tooth with a resorbable filling material’.
may be restored with suitable restorative material. Earlier authors treated endodontically involved
deciduous teeth with beechwood creosote and iodine.
VI. Partial Pulpectomy Various materials and techniques have been tried to
treat pulp involved deciduous teeth, with varying
Partial pulpectomy is considered as an extension of the
success.
pulpotomy procedure, whereby the radicular pulp is
amputated, short of total length of canal leaving vital Indications
tissue in the apical half. Technically, it is a vital pulp • Signs of irreversible pulpitis
therapy technique. Pulpotomy refers only to coronal • Non-vital radicular pulp with/without associated
extirpation of vital pulp tissue, while any amount of infection
pulp removal short of total extirpation may be referred • Minimal periapical changes with sufficient bone
to as partial pulpectomy. support
Indication • Two-thirds of the root length should be available
To control hemorrhage from the radicular orifice; when • Internal resorption without any obvious perforation
even after removing the coronal pulp, the hemorrhage • Strategically important tooth (for example, in case
remains uncontrolled. of the deciduous second molar where the permanent
first molar has not erupted)
Procedure • Good patient compliance
The coronal pulp is removed from the chamber. After
controlling the hemorrhage, approximately one half of Contraindications
the coronal portion of the radicular pulp is also • Systemic conditions like infective endocarditis
removed (Fig. 28.4a and b). • Lack of patient cooperation
• Excessive mobility
28
The canals and chamber are irrigated. If hemorrhage
is still not controlled, the pulpectomy procedure is • Non-restorable tooth
initiated. • Perforations of the floor of pulp chamber

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 Pediatric Endodontics 511

• Pathologic root resorption involving more than one- • The problem is further complicated by the reluctance
third of the root among general practitioners to treat such teeth due
• Excessive loss of bone support (pathological) to the difficulty of managing young, apprehensive
children and also the lack of experience of treating
• Presence of dentigerous cyst
the deciduous teeth.
• Periapical or interradicular lesion involving the crypt
of the developing permanent successor. Procedure
The pulpectomy procedure can be completed in one
Implications of Pulpectomy (Root Canal Treatment) visit or in two multiple visits.
in Deciduous Teeth A single/two-multiple visit pulpectomy may be
Root canal treatment in children may present difficulties undertaken depending on whether the radicular pulp
due to the following reasons: is irreversibly inflamed or non-vital, with/without an
• The root canal system in primary teeth usually have associated periradicular pathosis.
numerous lateral and accessory canals, areas of A. Single-visit pulpectomy
internal resorption, communication with the Single-visit pulpectomy (Fig. 28.5a to c) is preferred in
furcation and deviated canal shape, especially at the following cases:
apical area. • Presence of inflamed but remnants of vital radicular
• Mobility of the tooth, even if minor, pose difficulty pulp
in instrumentation. • An asymptomatic primary tooth with necrotic pulp
• The root canals must be obturated with resorbable tissue, without any acute symptoms such as cellulitis
materials, which should not interfere with the • Presence of a chronic buccal lesion without any active
eruption of the succedaneous tooth. discharge or acute symptoms.

a b

c
Fig. 28.5 Single-visit pulpectomy (a) Preoperative; (b) Diagnostic radiograph; (c) Postoperative
28

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 512 Essentials of Endodontics

B. Two-visit/multi-visit pulpectomy The anatomy of maxillary primary incisors also

Two-visit technique is preferred where acute/chronic facilitate access from the facial surface. The only
infection/exudate is present with or without associated variation would be the more extension to the
cellulitis (Fig. 28.6 a to c). incisal edge than with the normal lingual access in
order to provide straight line approach into the root
Procedure canal.
The steps involved are: ii. Posterior teeth: Access cavity preparation for the
a. Access cavity preparation: The access cavity primary posterior teeth are essentially the same as
preparation is the most important phase of root canal for the permanent teeth; however, following
treatment in deciduous teeth just like permanent teeth. differences between the primary and permanent
The basic objectives of access preparation, viz. gaining teeth are to be kept in mind during access cavity
straight line access and conserving the tooth structure preparation.
are followed in primary teeth also. • Configuration (bulbous shape) of the crowns.
i. Anterior teeth: Access cavity preparation for primary • Thin dentinal wall at the pulpal floor and in the
anterior teeth have traditionally been through the root.
lingual surface, except for the maxillary primary • The depth necessary to penetrate into the pulp
incisors. Since endodontically treated primary chamber is quite less than that in the permanent
incisors would be discolored, it has been teeth.
recommended to use a facial approach. The access • The distance from the occlusal surface to the pulp
cavity is filled with composite restoration floor of the pulp chamber is much less than in
immediately after the obturation to maintain permanent teeth (in primary molars, perforation
esthetics. of pulpal floor is common).

a b

28 c

Fig. 28.6 Two-visit pulpectomy: (a) Preoperative; (b) Diagnostic radiograph; (c) Postoperative

t.me/Dr_Mouayyad_AlbtousH
 Pediatric Endodontics 513

• When the roof of the pulp chamber is identified

and perforated, the entire roof should be
removed. Since the crown of the primary teeth
are bulbous, less extension towards the exterior
of the tooth is necessary to uncover the openings
of the root canals than in the permanent teeth.
b. Working length: Accurate determination of the
working length is a crucial step prior to pulpectomy in
primary molars. Due to limitations of radiographic
interpretation and high possibility of over-
instrumentation of the unevenly resorbed roots and
subsequent overfilling, the application of electronic
apex locators is recommended regardless of the stage
of root resorption.
Garcia-Godoy’s method of determining working length
The root resorption in primary teeth is initiated at the
site of the root which is closest to the permanent
successor. As the growth proceeds, the developing
tooth moves under the divergent roots of primary
molar. The position and size of the follicle affects the
pattern of resorption showing uneven root resorption
in one or more roots at any given time. This poses a Fig. 28.8 Working length measurement in deciduous
great difficulty in determining the exact working length teeth (permanent tooth bud below the apices of molar)
in primary teeth. To overcome this problem, Garcia-
Godoy (1987) suggested a new method of working • If permanent tooth bud is below the apices of the
length determination in primary molars. deciduous molar, instruments can be used for the
• If permanent tooth bud is within the furcation area, entire length of canals (Fig. 28.8).
use of instruments should be limited to a plane just Figure 28.9a and b exhibits lateral resorption of
occlusal to the occlusal plane of permanent tooth bud mesial root; subsequently obturated.
(Fig. 28.7).
c. Cleaning, shaping and irrigation: Cleaning and
shaping of root canals in deciduous teeth is carried out
using stainless steel hand files (usually not larger than
size 30) in routine cases. Flexible files are recommended
in curved/S-shaped canals. Operator should carefully
choose irrigating solutions due to possible chemical
interactions among different irrigants. Use of inter-
mediate solutions, such as saline or sterile distilled
water can prevent such toxic interactions.
d. Obturation: Various materials have been tried for
obturating primary root canals; no single material could
meet the requirements as described. Gutta-percha is not
a resorbable material, therefore, its use in primary teeth
is contraindicated.
Ideal root canal—filling material for primary teeth
should have the following characteristics:
• Should resorb at a similar rate as the primary root
• Should be harmless to the periapical tissues and to
the permanent tooth germ
Fig. 28.7 Working length measurement in deciduous teeth
(permanent tooth bud within the furcation area)
• Resorb readily if extruded beyond the apex
• Should be antiseptic
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 514 Essentials of Endodontics

ii. Calcium hydroxide

Calcium hydroxide has been used as obturating
material due to its antimicrobial properties. It is easily
resorbed when inadvertently extruded beyond the
apical foramen. Calcium hydroxide, in combination
with iodoform has shown favorable results in
deciduous teeth.
Advantages
• Biocompatible
• Antibacterial
• Resorbable
a
Disadvantages
• Depletion of material from root canal prior to
physiologic resorption of root.
• May lead to internal resorption (early resorption in
root canal may become a hollow tube for bacteria to
induce re-infection).
iii. Vitapex
Vitapex is a pre-mixed paste of 30.3% calcium
hydroxide and 40.4% iodoform (Fig. 28.10). It is packed
in a sterile syringe; the paste is injected into the canal
b
with disposable plastic needles.
When extruded into furcal or apical areas, it can either
Fig. 28.9a and b (a) Lateral resorption of mesial root; be diffused away or resorbed in part by macrophages
(b) Obturated root
within a week or two and causes no foreign body reaction.
This technique is easy to use for primary incisors;
• Should fill the root canals easily and adhere to root
however, pushing paste in narrow canals is difficult,
dentin
especially in primary molars.
• Should not shrink and discolor the tooth
• Should be easily removed, if necessary Advantages
• Should be radiopaque • Resorbable
• Harmless to successors
The commonly used obturating materials for deciduous
teeth are: • Easy to remove
• Suppresses residual bacteria in root canal/periapical
i. Zinc oxide eugenol region
Zinc oxide eugenol alone and in combination with formo-
cresol/formaldehyde, paraformaldehyde and cresol has Disadvantage
been widely used as obturating material in deciduous Low anti-bacterial effect
teeth. A combination of zinc oxide eugenol with
iodoform has also been effective as obturating material.
Limitations
• Limited antimicrobial action (tends to resorb at a
slower rate than the roots of the deciduous teeth).
• Causes irritation to periapical tissues; may lead to
necrosis of bone and cementum.
• May alter path of eruption of succedaneous tooth
(chances of retention of the overfilled material in

28 periapical region).
• Not bactericidal (combination materials do have
bactericidal properties). Fig. 28.10 Calcium hydroxide and iodoform paste

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 Pediatric Endodontics 515

iv. Iodoform paste Disadvantages

Iodoform pastes have better resorbability and dis- • May lead to periapical irritation
infectant properties than zinc oxide eugenol. It has • Yellowish brown tooth discoloration
excellent healing properties and is bactericidal. • May lead to cemental necrosis
Different formulations of root canal filling materials • Cannot be removed completely from the root canals
containing iodoform are available:
 Walkoff paste (parachlorphenol, camphor, menthol). Obturation Techniques
 KRI paste (parachlorphenol, camphor, menthol and
The ultimate goal of obturation is to create hermetic
iodoform).
seal in the root canals, so as to prevent re-infection of
 Maisto paste (parachlorphenol, camphor, menthol,
the pulp spaces. The selected filling technique should
iodoform, zinc oxide, thymol and lanolin).
fill the root canals without any over-fill and voids.
 Guedes-Pinto paste (iodoform, camphorated para-
chlorophenol). Various techniques are being used to obturate the
primary root canals.
Advantages The commonly employed techniques are as follows.
• Bactericidal
• Easy to remove i. Endodontic Pressure Syringe
• Biocompatibility The apparatus consists of a syringe barrel, threaded
Disadvantage plugger, wrench and threaded needle (different sizes
• May produce a yellowish-brown discoloration of the are available). The needle is inserted into the root canal
tooth crowns compromising esthetics. until resistance is felt. The obturating material is injected
into the root canal with mild pressure. The needle is
v. Endoflas withdrawn of 3.0 mm intervals, pushing the material,
Endoflas is available in powder: liquid form. The till the canal can be visibly filled at the orifice. Small
powder contains zinc oxide eugenol (56.5%), tri- gauge needles are flexible and can easily be maneuvered
iodomethane/iodine (40.6%), calcium hydroxide in the tortuous canals of primary molars. The dis-
(1.07%) and barium sulphate (1.63%). Liquid contains advantage of this method is, the needle is to be
eugenol and pentachlorophenol (Fig. 28.11). repeatedly withdrawn and inserted, which may disrupt
Advantages placement of obturating material in the canal. Air gets
• Hydrophilic material; can be used in mild humid root entrapped and the voids can be created using this
canal technique. More so, the technique is time consuming.
• Firmly adheres to root dentin provide a good seal Mechanical syringe with plunger system has also
• Ability to disinfect dentinal tubules and accessory been used, but with little success. The screw mechanism
canals that cannot be disinfected/cleaned mechanically of endodontic pressure syringe could generate
• Broad spectrum antibacterial effect sufficient pressure for placement of the obturating
• Biocompatible material.
• Easily removed by phagocytosis; making the
material resorbable. ii. Lentulo Spiral
Lentulo spiral is one of the commonly used instrument
for applying paste into primary root canals (also
effectively used in permanent teeth). The flexibility of
the instrument facilitate carrying paste even to narrow
and curved root canals. Various authors in their
respective studies have concluded that calcium
hydroxide when inserted using a Lentulo spiral
technique showed better radiodensity, especially in
curved canals. The disadvantages of using this
technique are, frequent fracture of instrument and also
the probability of extrusion of obturating material
beyond the apex.

Fig. 28.11 Endoflas

A reamer (Fig. 28.12) is also used as a paste carrier
(reamer coated with obturating paste is inserted into
canal with clockwise rotation along with up and down
28

t.me/Dr_Mouayyad_AlbtousH
 516 Essentials of Endodontics

pluggers is limited, the paste cannot be placed in

narrow/curved canals (effective only in wider
canals).

iv. Jiffy Tube

The premix slurry of zinc oxide eugenol is coated in
the root canal walls with the help of paper points. The
zinc oxide eugenol mixture is loaded in the tube (Jiffy
tube). The tube is gently squeezed, placing tip of tube
at the canal orifice and pushing the material into the
root canal. Since no apical pressure is applied, chances
of apical extrusion are minimum.
Fig. 28.12 Reamer
v. Conventional/Insulin/Tuberculin Syringe
The pre-mixed zinc oxide eugenol is loaded into the
syringe with a standard 3/8-inch needle and 26–30
gauge. The material is expressed into the canal by slow
finger pressure on the plunger until the canal is filled.
The disadvantage of syringe technique is the choice of
needle gauge; if small sized, may pose difficulty in
pushing the material, and if large sized, may not fit
into many canals. Placement of obturating material may
also create voids in the canal.
Insulin syringe (Fig. 28.14) is also available with
smaller gauge size. A thin and flexible metal tip (viz.
NaviTip) has been introduced to deliver root canal
sealer. The NaviTip is available in different sizes with
the provision to adjust rubber stop.
Fig. 28.13 Past inject
It has been pointed out that pulpally treated primary
motion. A rubber stop can be used to keep the reamer teeth may occasionally present a problem of over-
in a predetermined length. Past inject (micromega), a retention. It is hypothesized that the large amount of
paste carrier, with improved blade design (flat blades) zinc oxide in the canals may impair the physiological
has also been introduced (Fig. 28.13). Manufacturer resorption and lead to prolonged retention of the
claims better placement of obturating material with this crown. The teeth should be periodically evaluated for
carrier. Another carrier, Bi-directional spiral (EZ-fill), any signs of failure or over-retention and managed
effectively control the obturating paste placement in accordingly. The success rate of pulpectomy in
the root canal. The spirals at the coronal end spin the deciduous teeth is quite satisfactory.
material down to apex and the spiral at apical end spin
the material coronally. The chances of apical extrusion
is minimum with bi-directional spiral obturating paste
carrier.

iii. Incremental Filling Technique

An endodontic plugger corresponding to the size of the
canal is selected. A rubber stop is fixed 2.0 mm short of
the root canal length. Pre-mixed zinc oxide eugenol or
any other obturating paste is inserted into the root canal
in small increments. The process is repeated until the
canal is filled to the cervical area. A few authors prefer

28 placing the material in bulk and pushing it into the

canals with endodontic pluggers. The disadvantage of
this technique is, since the flexibility of endodontic Fig. 28.14 Insulin syringe

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 Pediatric Endodontics 517

VIII. Apexification/Apexogenesis USE OF ANTIBIOTICS IN PEDIATRIC ENDODONTICS

The diseased anterior primary teeth are usually extracted Antibiotics play an important role in pediatric endo-
because they have shown to create developmental dontics. Systemic antibiotics have been extensively used
defects in permanent successors. In rare conditions for the management of odontogenic infections. The
(aggressive rampant caries), apexification using calcium antibiotics should be selected based on age, overall state
hydroxide/tricalcium phosphate has been tried. of the patient’s health and up to date microbiological
In permanent teeth the closure of apex may take three knowledge. The ideal duration of antibiotic therapy
years after eruption. Certain factors may interfere with should be capable of preventing both clinical and
the normal development of the root. Because of the microbiological relapse.
important role of Hertwig’s epithelial root sheath in
The majority of infections of endodontic origin can
continued root development after pulp injury, effort
be effectively managed without the use of antibiotics.
should be made to maintain its vitality.
Chemo-mechanical debridement with drainage
The clinical situation may vary: through the root canal system or by incision and
• In case of immature tooth with vital pulp, apexogenesis drainage of soft tissue, help in healing process.
is undertaken to preserve the vitality and allowing Topical antibiotics have been widely used as intracanal
completion of root development (Fig. 28.15a and b).
medicaments. Bacteria within the root canals are
• In case the immature tooth with necrotic pulp,
inaccessible to irrigation and the mechanical cleaning
apexification is performed to induce a calcific barrier
process. It is opined that antibiotics induced within the
at the open apex (Fig. 28.16a and b).
canal may be able to diffuse into inaccessible areas to
The details of the procedure being followed is
reduce the number of viable bacteria and improve
described in Chapter 25.
periapical healing.
Prophylactic antibiotics should be given to prevent
infective endocarditis as recommended by American
Heart Association. These can also be prescribed before
long duration procedures.

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A systematic review of root canal filling materials for 39. Moskovitz M, Sammara E and Holan G. Success rate of root
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Topics: 2012; 23:50–72. 41. O’Sullivan SM and Hartwell GR. Obturation of a retained
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teeth: a review. Pediatric Dent.: 1983; 5:33–37. 44. Ounsi HF, Debaybo D, Salameh Z , Chebaro A and Bassam
H. Endodontic considerations in pediatric dentistry: A clinical
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28. Hill MW. The survival of vital and non-vital deciduous molar
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47. Praveen P, Anantharaj A, Venkataragahavan K, Rani P, Sudhir 58. Tan JME, Parolia A and Pau AKH. Intracanal placement of
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54. Sarkar S and Rao AP. Number of root canals, their shape, 65. Waterhouse PJ. Formocresol and alternative primary molar
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antibacterial drugs. Int. Endod. J.: 2004; 37:132–138. Pedod. Prev. Dent.: 2005; 23:7–12.

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 Chapter
29
Geriatric Endodontics

Geriatric dentistry is defined as the delivery of dental ii. Changes in pulp-dentin complex
care to ‘old population’ involving treatment of problems • The number and size of odontoblasts and fibroblasts
associated with normal aging and age-related diseases. in pulp decrease; odontoblastic processes degenerate
Presently, population over the age of 65 is considered with age (fewer odontoblastic processes extend to
as older adults, whereas ‘old’ individual is over the age dentinoenamel junction).
of 75 (the chronological age may vary in different parts • Remaining cells of pulp become less active.
of the world). In order to provide better oral health care, • Number of collagen fibers of pulp increase (increased
it is mandatory to focus on the knowledge and fibrosis with age may not be due to formation of
education in the field of geriatric dentistry. collagen; persistence of connective tissue sheath in
Clinical management in elderly patients is becoming an increasingly narrow pulp space may be the
increasingly challenging as older people are aware of reason).
their health and related ailments. The challenges include • Number of blood vessels and nerve fibers decrease.
biological and psychological differences from the younger • Prevalence of occurrence of denticles (pulp stones)
patients as well as treatment complications in older increases both in coronal and radicular pulp.
population. Older adults now prefer saving their teeth at • Pulpal arteries may demonstrate arteriosclerotic
any cost. Over the years, the preservation of the natural changes; decrease of the lumen size, resulting in
dentition has been so successful that tooth loss is no longer thickening and hyperplasia of elastic fibers.
accepted as inevitable. Endodontic treatment is less
• Calcification of pre-capillaries and arterioles may be
traumatic than extraction/implantation, etc. especially in
seen (Fig. 29.1).
older patients; systemic problems may also necessitate
• Pulp tissues recede due to secondary and tertiary
opting for less traumatic procedure in older adults.
dentin formation (Fig. 29.2a and b).
The quality of life for older patients can be improved
by saving teeth through endodontic treatment, which
can have a significant impact on oral, physical and
mental health. The National Institute on Aging has
suggested that all oral health professionals should
receive education concerning treatment of older adults
as part of their basic professional learning.
As the body ages, retrogressive changes take place
in body tissues. Similarly age changes do affect oral-
dental tissues.

CHANGES DUE TO AGING IN ORAL DENTAL TISSUES

i. Changes in enamel
• Loss of enamel (tooth substance loss) due to attrition,
abrasion and erosion
• Decrease in permeability
• May become brittle Fig. 29.1 Diffuse calcification in an aged pulp

520

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 Geriatric Endodontics 521

junction moves farther from the radiographic apex

with continued cementum deposition.
– The calcification process associated with aging
appears to be of a linear type. Dentinal tubules
become more occluded with advancing age;
decreasing tubular permeability. Lateral and
accessory canals can calcify; thus decreasing their
clinical significance.
iii. Changes in cementum/root
• Continuous deposition of cementum (hyper-
cementation)
• Apical root resorption
• Cementodentinal junction recedes
iv. Miscellaneous changes
Fig. 29.2a Decreased pulp volume by continuous • It is hypothesized that the older adults may exhibit
deposition of dentin adverse reaction to injury or they might be more
resistant because of decreased permeability of dentin
(no proven documentation).
• No change in periradicular tissues as regard
cellularity and vascularity with age.
• Similar pattern of healing in young and old (critical
to healing is vascularity).
• Systemic conditions may affect endodontic treatment
prognosis at any age.

ENDODONTIC TREATMENT IN ELDERLY PATIENTS

Endodontic procedures in the elderly have always been
challenging due to various psychological and technical
perspective. The long-term planning for the older adults
has become more critical. Every phase of the treatment
is important from geriatric point of view. The endodontic
treatment protocol in elderly is described as follows.

a. History and Clinical Examination

Fig. 29.2b Cut section of an old tooth showing attrition, It is important to focus on factors that indicate the
reduced pulpal space and sclerotic dentin probable risks involved in treating the older patient.
Clinician must recognize that the biological age of an
• Primary dentin is formed before tooth eruption; individual is far more important than chronologic age.
whereas, secondary and tertiary dentin is formed as In general, aging may lead to changes in the cardio-
the age advances. The deposition of secondary and vascular, respiratory and central nervous systems that
tertiary dentin varies in different teeth, such as: warrant intake of drugs. The decline in renal and liver
– In anterior teeth, secondary dentin deposition is function in older patient should also be considered
in incisal area and in lingual wall of pulp chamber when predicting interaction of drugs that may be used
– In posterior teeth, secondary dentin deposition is in dental treatment. The elderly usually takes more
in the floor of pulp chamber. drugs than the general adult population and so the
– Tertiary dentin is also formed due to irritation by adverse drug reactions are more common in these
caries, trauma, etc. The tertiary dentin can fill the patients. It is important that the clinician take a careful
entire pulp chamber. history and regularly update the same in consultation
– In general, pulp volume is inversely proportional
to age; as age increases, pulp size decreases. The
overall canal size decreases as the cementodentinal
with the patient’s physician.
The intraoral and extraoral examination provides
valuable information about the previous treatment. The
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 522 Essentials of Endodontics

factors that contribute to oral cancers accumulate with kept in mind when treating elderly. Pain associated
age; many systemic diseases may manifest such signs with vital pulps usually reduces with age. The severity
and symptoms. also diminishes over time. The healing capacity may
Missing teeth contribute to reduced functional and may not be reduced; however, necrosis may occur
ability. The resultant loss of chewing efficiency leads quickly after microbial invasion.
to intake of softer and more cariogenic foods. Saliva The geriatric patients usually do not complain about
plays a significant role in the maintenance of oral and signs and symptoms of pulpal and periapical disease,
general health. Aging may not have direct role on considering these to be of minor nature as compared
salivary secretion; however, salivary hypofunction can to other ailments.
be due to excessive use of medications. Xerostomia
affects more than 30% of population above the age of b. Diagnosis
65. Xerostomia leads to increased susceptibility of Initial examination, such as palpation, percussion, etc.
dysphagia and caries. is carried out in routine. Transillumination can be
The compensating bite produced by missing and effective to detect cracks, a common occurrence in
tilted teeth can cause temporomandibular joint dys- elderly patients. The presence of micro cracks might
function or loss of vertical dimension. Diminished not be significant in older teeth; however, vertical cracks
eruptive forces with age, however, reduce the amount can be the cause of pulpal or periapical diseases. The
of mesial drift and supraeruption. diagnostic features are:
Gingival recession exposes cementum and dentin, i. Pulp testing
which creates sensitivity. The excavation of root caries The response to stimuli may be weaker in elderly
may irritate the pulp; may lead to pulp exposures. patients because of the fewer nerve branches present
Exposures of pulp on one root surface of a multi-rooted in older pulps. This may also be due to retrogressive
tooth can result in uncommon clinical situation of the changes resulting from mineralization of the nerve and
presence of both vital and non-vital pulp tissue in the nerve sheath.
same tooth.
• Slow and gentle testing should be carried out to
Attrition, abrasion and erosion also expose dentin determine status of pulp and periapical tissues
through a slower process that allows the pulp to (electric stimulus in patients with pacemakers is not
respond with dentinal sclerosis and reparative dentin. recommended. The same caution holds true for
The reduced organic component of the dentin may electrosurgical units).
increase susceptibility to cracks and cuspal fractures.
• Pulps with a high degree of pulpal calcification may
Pulpal exposures caused by cracks may not present
give false negative result to thermal tests; electrical
acute problems in older patients.
pulp testing can be effective as there is no difference
Periodontal disease may be the principal problem of electric stimulation threshold between young and
for older adults. The relationship between pulpal and old pulps.
periodontal disease can be expected to be more • A test cavity is generally less useful because of
significant with age. Patients with diabetes have reduced dentin innervations.
increased periodontal disease and may have a reduced
• Discoloration of single teeth usually indicate pulp
likelihood of success of endodontic treatment, espe-
necrosis; however, in geriatric individual the reason
cially in case with preoperative periradicular lesion.
may be different. Dentin gets thicker in older adults
The dental pain usually has a pulpal or periapical and the tubules become less permeable to breakdown
origin that may require root canal treatment or products from the pulp. A yellow opaque color
extraction. The status of pulpal or periapical disease is produced with age indicate progressive calcification.
to be ascertained to finalize treatment modality. It is
emphasized that pulpal symptoms are usually chronic ii. Radiographs
in older patients; the sources of pain should be ruled Radiographs are adjunct to diagnostic aids even in older
out before some diagnosis is arrived at. Older patients adults. However, several physiologic, anatomic changes
may have had the experience of both the treatments can significantly affect their interpretation. Film
and know the practical implications. placement may be a problem in older patients; there-
Orofacial pain is more common in elderly and fore, film holders are preferred. Sometimes, exposure

29 significantly more prevalent in females. This might be

due to hormonal changes that occur in females with
age. The possibility of non-odontogenic pain should be
time need to be increased to accommodate dense bone
(bony changes can be effectively detected by digital radio-
graphy as compared to conventional radiography).

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 Geriatric Endodontics 523

In older patients, pulp recession is accelerated by e. Endodontic Procedure

reparative dentin and complicated by pulp stones and The endodontic procedure involves:
dystrophic calcification. Minute pulp calcifications may i. Anesthesia
not be visible on radiographs; however, receding pulp The cutting of dentin does not produce the same level
horns are apparent. Radiographs do detect a number of response in an older patient as in young patients.
of roots, root canals, size and configuration of pulp The number of nerve endings in dentin is reduced, and
spaces and also the proximal caries. they do not extend as far into the dentin as required. In
addition, the dentinal tubules are more calcified. A
c. Treatment Planning painful response may not be encountered until very
The limited life expectancy coupled with psychological near to pulp or actual pulp exposure has occurred.
constraint in older adults should not alter the requisite Older patients may accept treatment without anes-
treatment plan; do not plan compromised treatment in thesia; preferably should be persuaded that anesthesia
any case. It is important that all older patients be well is necessary for their routine operative procedures.
informed of the probable risks and also the alternatives. Anatomic landmarks that are used as guides to
Such patients deserve thorough explanation for their needle placement during block and infiltration
disease and treatment planning. Geriatric individuals injections are usually more distinguishable in older
are mostly cooperative and appreciative patients. patients; however, during supplementary intra-
One-appointment procedures are usually preferred ligamentary injections, reduced width of periodontal
in older patients. The time span of one appointment ligament makes needle placement difficult.
should also be taken care of, as the elderly people may The reduced volume of the pulp chamber makes
not be able to sit on the chair for long. The waiting intrapulpal anesthesia difficult in single-rooted tooth
period should also be managed. and almost impossible in multi-rooted teeth.
The older patient should be evaluated psycho- ii. Isolation
logically to determine the ideal time of the day and
Reduction in salivary flow and gag reflex reduces the
length of time necessary to schedule treatment.
need for a saliva ejector and other isolation procedures.
Morning appointments are usually preferred for older
There might be a need to use artificial saliva. Elderly
patients. Some patients prefer afternoon visits to avoid
patients usually do not accept rubber dam placement.
early morning stiffness.
The retention of roots of excessively worn teeth is a iii. Access cavity preparation
desirable objective in older adults, as it maintains the The identification of canal orifices are usually difficult
alveolar bone. The loss of tooth roots is a known cause for older patients. The access cavity need to be
of alveolar bone resorption. The absence of tooth roots deepened to visualize and negotiate the canal orifices.
leads to resorption of alveolar bone. Moreover, loss of Aging may reduce the volume and coronal extent of
teeth alters the physical properties of the cortical the pulp chamber; however, the position of canals
mandibular bone, such as thickness, elastic/shear remain the same and can be negotiated during
moduli and stiffness, subsequently weakening the conventional, but deep access cavity preparation.
mandible. Location and penetration of the canal orifice are often
The procedures, such as, pulp capping, etc. are not difficult and time consuming in older adults because
as successful in older teeth as in younger ones; because of narrow/calcified canals. Very few canals of older
of reduced blood supply. teeth, even maxillary anterior teeth, have adequate
diameter to allow the effective use of broaches. Small
d. Preparation before Endodontic Treatment files along with lubricants are preferred for negotiation.
Before initiating endodontic procedures, the patient Magnification aids are mandatory in identification
should be mentally prepared for the minor implications and instrumentation of geriatric root canals.
during and after the treatment. Patient’s consent is iv. Preparation (cleaning and shaping)
important; patient’s physicians consent and instruc- The physiological narrowing of root canals resulting
tions, if any, should also be recorded. Patients should from the aging process presents a different clinical
be made comfortable adjusting the chair position, situation as compared to calcification/obliteration
light, etc. as per need of the patient. The use of pillow resulting in younger individuals. The physiological
to support the neck improves patient comfort. A
few patients prefer keeping pillow under the legs as
well.
narrowing of root canals (calcification) is more
concentric and linear. This allows easier preparation
of canals once they are negotiated.
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 524 Essentials of Endodontics

The canal in the elderly should be flared to facilitate • Isolation procedures pose difficulties as these
irrigation procedure; it reduces stress on root canal. patients may suffer from breathlessness, gagging, etc.
Calcified canals may reduce the clinician’s tactile • Since healing may take longer period, the geriatric
sense in identifying the constriction clinically. Increased individual should be kept informed and assessed
incidence of hypercementosis makes it difficult to assess periodically.
the accurate positioning of the terminus. Reduced • Geriatric patients should be given utmost respect to
periapical sensitivity in older adults may lead to keep them psychologically motivated.
inadvertent penetration of apical foramen. Instrumenta-
tion with crown-down technique reduces instrument Management of Root Exposure
stress and also chances of instrument separation. Root exposure is universally prevalent in older
individuals. The root exposure may lead to root caries
v. Obturation
and/or loss of cementum leading to exposure of dentin.
The obturation procedures in geriatric patients should
It may involve pulp. Gingival recession is the apical
not generate pressure in the mid-root area, which may
shift of marginal gingiva from its normal position on
lead to root fracture. Passive placement of the obturat-
the crown of the tooth to the level on the root beyond
ing material is preferred. Resilon/thermoplasticized
the cementum-enamel junction. The esthetics is also
gutta-percha provides an effective seal in older adults.
compromised in case of recession and/or root caries
Permanent restoration should also be placed as soon
(Fig. 29.3a and b).
as possible to maintain stomatognathic system.
The exposed root(s) should be covered to overcome
vi. Repair after endodontic treatment the problem of sensitivity and to improve upon the
Repair of elderly patients is normally delayed due to esthetics. The following conditions are mandatory for
increase in atherosclerotic changes in blood vessels and successful root coverage.
also decrease in stimulation of bone formation (porosity
of bone increases and mineralization decreases with age).

Managing elderly endodontic patient: Key features

• Detailed history of systemic problems; intake of medication
• Short appointments, preferably during noon time
• Psychological motivation required
• Pillow for neck comfort in dental chair (may also be for legs)
• Mouth props for limited jaw opening
• Magnification to negotiate narrow/calcified canals
• Isolation should be managed without rubber dam
• Modification in access preparation (deep access cavity)
• Rotary crown-down instrumentation to reduce treatment time
• Gentle pressure during instrumentation and obturation
• Vital pulp therapy may have lower success rate (not preferred
in elderly) Fig. 29.3a Recession in multiple teeth
• Judicious approach in case of retreatment
• Repair is delayed

Challenges in Treating Elderly Patients

Treating elderly patients are always challenging for the
clinicians. The operator must exercise patience and
satisfy these patients according to their needs. The
features, which can be challenging during endodontic
procedures are:
• Heavy restorations (already restored teeth) may
interfere with endodontic diagnosis and treatment
• Pulp calcification may create problems in negotiating

29 the canals
• Periodontal problems in geriatric patients affect
prognosis of the treatment. Fig. 29.3b Caries in multiple teeth

t.me/Dr_Mouayyad_AlbtousH
 Geriatric Endodontics 525

• Sufficient interdental papilla adjacent to gingival

recession area
• Sufficient blood supply ensured to the donor tissue
• The decay/abrasion of root surface be managed prior
to covering.
Minimum of 1.0–2.0 mm attached gingiva is adequate
for covering; inflammation be kept under control.
The root coverage can be managed either by surgical
or non-surgical methods.

a. Surgical Methods
• Pedicle soft tissue graft Fig. 29.5a Recession of anterior teeth in an old patient (pre-
operative)
• Free soft tissue graft
• Double papillary flaps
• Coronally advanced flaps
• Connective tissue grafts
• Guided tissue regeneration procedures

b. Non-surgical Methods
• Pink glass-ionomer cement (Fig. 29.4a and b)
• Gum veneers (Fig. 29.5a and b)

Fig. 29.5b Gum veneers to mask the recession (post-

operative)

The non-surgical procedures are preferred in older

adults as surgical procedures might not be very success-
ful. The non-surgical methods improve esthetics,
relatively inexpensive, painless and easily maintained
by the older patients. They can also be used as interim
measures till final treatment is being planned.

Fig. 29.4a Recession in aged patient (preoperative)

BIBLIOGRAPHY
1. Allen PF and Whitworth JM. Endodontic considerations in
the elderly. Gerodontology: 2004; 21:185–194.
2. Arola D and Reprogen RK. Effects of aging on the mechanical
behavior of human dentin. Biomaterials: 2005; 26:4051–4061.
3. Atkinson JC, Grisius M and Massey W. Salivary hypofunction
and xerostomia: diagnosis and treatment. Dent. Clin. North
Am.: 2005; 49:309–326.
4. Barjilay I and Tamblyn I. Gingival prosthesis—A review. J.
Can. Dent. Assoc.: 2003; 69:74–78.
5. Bennett CG, Keelln EE and Biddington WR. Age changes of
the vascular pattern of the human dental pulp. Arch. Oral
Biol.: 1956; 10:995–998.

Fig. 29.4b Recession restored with pink glass-ionomer

cement (postoperative)
6. Berkey D, Berg RG, Ettinger RL, Mersel A and Mann J. The
old-old patient: the challenge of clinical decision making.
JADA: 1996; 127:321–332.
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 526 Essentials of Endodontics

7. Bernick S and Nedalman C. Effect of aging on the human 17. Mekayarajjananoth T, Kiat-annuary S, Sooksuntisakoonchal
pulp. J. Endod.: 1975; 3:88–94. N and Salinen T. The functional and esthetic deficit replaced
8. Ciancio SG. Medications’ impact on oral health. J. Am. Dent. with an acrylic resin gingival veneer. Quint. Int.: 2002; 33:91.
Assoc.: 2004; 135:1440–1448. 18. Mysore AR and Aras MA. Understanding the psychology of
9. De Rossi SS and Slaughter YA. Oral changes in older patients: geriatric edentulous patients. Gerodontology: 2012; 29:
a clinician’s guide. Quint. Int.: 2007; 38:773–780. e23–27.
19. Perlea P, Nistor CC, Iliescu MG, Iliescu A, Aminov L, Vataman
10. Fridman M J.: Gingival masks: a simple prosthesis to improve
M and Iliescu AA. High risk in root canal neogiation in elderly
the appearance of teeth. Compend. Contin. Educ. Dent.:
patients: clinical case series. Endodontics: 2015; 5:52–58.
2000; 21:1008–1010.
20. Qualtrough AJ and Mannocci F. Endodontics and the older
11. George C. Evidence-based approach for treatment planning patient. Dent. Update: 2011; 38:559–566.
options for the extensively damaged dentition. CDA.: 2004;
21. Ranjitkar S, Taylor JA and Townsend GC. A radiographic
32:983–990.
assessment of the prevalence of pulp stone in Australians.
12. Gorduysus MO. Geriatric endodontics, clinical changes and Aust. Dent. J.: 2002; 47:36–40.
challenges. EC Dent. Sci.: 2016; 7:38–40. 22. Ship JA, Pillemer SR and Baum BJ. Xerostomia and geriatric
13. Gunay H, Guertsen W and Luhars A. Conservative treatment patient. J. Am. Geraiatr. Soc.: 2002; 50:535–543.
of periodontal recession with Class V defects using gingiva 23. Singh SK, Kanaparthy A, Kanaparthy R, Pillai A and Sandhu
shade composite—a systematic treatment concept. Dent. G. Geriatric Endodontic. J. Orofac. Res.: 2013; 3:191–196.
Update: 2011; 38:124. 24. Sperber GH and Yu DC. Patient age is no contradiction to endo-
14. Johnstone M and Parashos P. Endodontics and the ageing dontic treatment. J. Can. Dent. Assoc.: 2003; 69:494–496.
patient. Aust. Dent. J.: 2015; 60:20–27. 25. Toto PD, Kastelic EF, Duyvejonck KJ and Rapp GW. Effect of
15. Joshi N, Parolia A, Kundbala M and Manuel ST. A age on water content in human teeth. J Dent Res 1971;
conservative method to reproduce lost gingival tissue—an 50:1284–1285.
innovative approach. Nepal Med. Coll. J.: 2009; 11:214. 26. Walton RE. Endodontic considerations in the geriatric patient.
16. Liu P, McGrath C and Cheugn G. What are the key endodontic Dent. Cl. North Am.: 1997; 41:795–816.
factors associated with oral-health related quality of life? Int. 27. Zander HA and Hurzeler B. Continuous cementum
Endod. J.: 2014; 47:238–245. apposition. J. Dent. Res.: 1958; 37:1035–1044.

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 Chapter
30
Magnification in
Endodontics

The art of dentistry is based on precision. The human working with less than 25° forward movement of head
eye may not be able to achieve the requisite precision leading to less muscle fatigue (Fig. 30.1).
on all occasions. Visualizing the oral cavity, more so There are three types of loupes:
the morphology of pulp spaces, always pose a challenge • Flat plane (single-lens) loupe: It consists of a single lens,
to the clinician. The unaided human eye can visualize which is fairly inexpensive. However, plastic lens
only up to 0.2 mm (200 microns). This means that when used might not be always correct. This type of loupe
two lines are drawn parallel to each other with a creates stresses compromising with posture [TTL-
distance of 0.2 mm between them, the human eye can through the lens (fixed loupe)].
visualize it as two separate lines. If the separation is • Galileian lens (two-lens) loupe: Two lens system is a
less than 0.2 mm, the eye will detect it as a single line. compact system providing up to 4.5X (magnification)
Since long, higher magnifications have been used to [TTL—through the lens (fixed loupe)].
study cell growth, division and mutation, etc. When • Prism loupe (prism roof design) folding the path of light:
working without magnification, head is to be forwarded Prism loupes are advanced type of loupes providing
at an angle which may cause muscle fatigue leading to up to 6.0X. The lens can be flipped-up during a
a disease entity called Tension Neck syndrome (TNS). procedure. They provide a larger field of view from
Such patients complain of headache and pain in inter- longer distance minimizing stress factor (flip-up
scapular muscles leading to cervical disc degeneration loupe).
or spondylosis. The magnifying devices can enhance
Loupes, despite of providing the required magnifica-
working posture by maintaining set focal range (loupes)
tion, have their own limitations. It limits to only one
or by location of fixed binoculars (microscope) or on
magnification. The loupe becomes heavier as the
LCD screen (procedure scope). It is also emphasized
magnification increases. Loupes have a fixed focal
that improper adjustments of these devices may worsen
the existing pain and injury to neck muscles.

MAGNIFICATION TYPES
In earlier days magnifying lenses have been tried but
with little success. The lenses had to be hand held by
the operator. The magnification provided was not
sufficient and also they suffered from spherical and
chromatic aberrations.
There are three basic types of magnification; the
loupes, procedure scope and the operating microscopes.
Endoscope and orascope are also magnification
gadgets.

i. Loupes
Loupes, also referred to as telescope, are usually used
magnification device in dentistry. The loupes allow Fig. 30.1 Magnifying loupe

527

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 528 Essentials of Endodontics

length; hence, do not contribute to ergonomics. Since Noah Chivian, an endodontist, introduced 8X
the focal length of the loupes is fixed and cannot be microscope in the field of endodontics. Dr Carr
changed, the distance from the lens to the object being introduced the first ergonomically configured operating
narrow; the operator has to bend forward towards the microscope for routine endodontic procedures. The use
patient in order to see the operative field clearly. The of the dental operating microscope in endodontics has
occupational stresses cannot be prevented. Illumination progressed over the years. Dr Carr’s statement, ‘You
is achieved with a head gear, which casts shadow over cannot treat what you cannot see’, has inspired a great
the operating field. number of endodontists to add microscope to their
normal armamentarium. He is aptly known as the
Advantages
‘Father of Microscopic Endodontics’. According to Dr Carr,
• Easy manipulation; no training required the microscope is simply an avenue for greater
• Inexpensive competence and that there are some procedures that
Disadvantages can only be performed with a microscope and almost
• Maximum magnification is 6X all procedures are performed more competently using
a microscope. Microscopes provide us the ability to
• Accessories like beam—splitter and video camera can-
observe and evaluate at low power; subsequently, a
not be attached to a loupe for better field magnification
higher power can be used for working and inspection.
• Higher magnification loupes are heavy (flip-up loupes)
A well-illuminated field visualizing any area of the oral
• Image is not stable due to head movement cavity is required to perform any procedure under the
ii. Procedure Scope microscope.
The visual information provided by the operating
The procedure scope offers optimal ergonomic benefits microscope is, in fact, not indicative of the magnification
by facilitating neutral head posture. A camera is placed that is being employed. The actual amount of visual
above the patient’s oral cavity projecting up to 20X information is the area under the scope (the number of
image onto a large flat LCD screen. The operator moves horizontal pixels multiplied by the number of vertical
the camera freely over the patient’s oral cavity while pixels). A microscope at 10X (magnification) provides
visualizing at the screen. 100 times the amount of visual information compared
to the naked-eye view (Table 30.1).
iii. Operating Microscope The comparison of different magnification aids is
The first microscope used in clinical procedures was tabulated in Table 30.2. The comparative clinical
introduced by Apotheker in 1981. In early eighties, implications are summarized in Table 30.3.

Table 30.1 Magnification and resolution of various magnification systems

Magnification device Magnification Resolution ( mm) Resolution (microns)
Unaided human eye Nil 0.2 200
Low magnification loupes 2.5X 0.08 80
High magnification loupes 6X 0.05 50
Microscope (low) 6.4X 0.031 31
Microscope (med) 10X 0.02 20
Microscope (high) 20X 0.01 10

Table 30.2 Magnification and resolution of various magnification systems

Loupes Procedure scope Microscope
Usually fixed magnification (2 to 6X) Variable magnification (2 to 20X) Variable magnification (2 to 20X)
Focusing by neck Focusing by camera Focusing by microscope
No light Standard light Standard light
20°–40° forward head posture Head posture near neutral Head posture near neutral
Ordinary/standard equipment Standard equipment Micro equipment

30 3-D image convergence angle

Less expensive
2-D image on screen
Less expensive
3-D image binocular vision
Expensive

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 Magnification in Endodontics 529

Table 30.3 Comparative clinical implications of magnification aids

Magnification type Head position Vision Operator movement Direction of light
TTL (fixed) loupes 20° to 40° forward Three-dimensional Moderate movement, At an angle (less than 15°)
(convergence angle) depends on working
range of loupes
Flip-up loupes 20° to 30° forward Three-dimensional Moderate movement, At an angle (less than 15°)
(convergence angle) depends on working
range of loupes
Procedure scope Neutral Two-dimensional (on Free movement Parallel to operator’s sight
screen)
Microscope Neutral Three-dimensional Restricted movement Parallel to operator’s sight
(binocular vision)

iv. Endoscope human use (literally known as engineering of human

The traditional endoscope consists of rigid glass rods factors). One of the major advantages of the use of the
with flexible and non-flexible variants. An optical lens dental operating microscope is the ergonomics
with a diameter of 0.9 mm provides the clinician a associated with its use. The operating microscope
magnification up to 20X. allows the operator to sit in an upright, neutral and
An improved version of endoscope (2.7 mm lens balanced posture with minimum neck, shoulder and
diameter and 3.0 cm long rod-lens) is recommended lower back muscle fatigue. The increased comfort
for non-surgical procedures. The rod-lens endoscope allows the operator to work more efficiently for longer
provides greater magnification and a clear view of the periods of time. Since the eyes are focused at infinity,
field as compared to the loupes. the eye strain is minimum. The operators working with
The Endoscope should not be used to retract gingival the aid of a microscope use micro movements and light
tissue while viewing a surgical field (assistant should pressure.
preferably retract the gingival tissues). Hemostasis Researchers studying human biometrics have
of the surgical site, is also important before using measured the load on the neck and shoulder muscles
endoscope. and have found that the load doubles with every
2.0–3.0 centimeters the head shifts forwards from the
v. Orascope ideal upward posture.
An orascope is a fiberoptic endoscope. Fiberoptics are The ideal operator zones are in the 7 to 12 o’clock
made of plastics; they are light weight and are flexible. positions for right-handed operators, and 5 to 12 o’clock
The fiberoptic endoscope (orascope) is designed for for left-handed operators. The key to proper ergonomics
intracanal visualization. is to seat yourself first in the most comfortable and
neutral position. The operator sits with his/her thighs
The focus and depth of field of orascope is from
parallel to the floor with the hips slightly elevated, feet
0.0 mm to infinity (∞). This allows the orascope to
planted firmly on the ground, shoulders erect, straight
provide imaging of apical end of the canal without
and perpendicular to the floor and arms stretched
actually inserting up to that level. Orascope facilitates
forwards with the elbows close to the body. The micro-
visualization of the treatment field at various angles
scope is then adjusted to the eyes in this position
and distances without losing focus and depth of field.
without bending forward. The patient is adjusted
A 0.8 mm fiberoptic size enables the orascope to go
between the hands to maintain this neutral position of
down into canal (canal is prepared up to size 80 or 90
the operator.
at the coronal half before inserting orascope). Orascope
visualization may be difficult in curved canals, because It has been reported that the most common reason
of limited flexibility of the instrument. The canal should for not using a microscope is the difficulty in
be dried before viewing with orascope. positioning and adjusting the eyes of the operator.
Mirrors are essential to examine the beveled root-end
preparation in surgical endodontics, although direct
ERGONOMICS vision is preferred over indirect, if convenient. An
Ergonomics is derived from Greek words, ‘ergon’
meaning work and ‘nomoi’ means natural laws; science
of refining the design of products to optimize them for
optimal operating position with a good front surface
mirror is a critical factor in the successful use of
operating microscope.
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 530 Essentials of Endodontics

The most comfortable position of the operator is the • A more relaxed eye position, as the optical properties
12 o’clock position for visualization of almost all teeth of viewing through a microscope eliminate the need
(Fig. 30.2). Right quadrant of the lower arch can also be to converge the eyes for focus
visualized in the 9 to 11 o’clock positions. Advantage • Illumination without shadows due to coaxial lighting
of the 9 to 11 o’clock positions is that they allow direct from the microscope
visualization of the occlusal surfaces of the teeth in the • An apparent increase in fine motor skills due to
3rd and 4th quadrant. increased visual acuity and visibility
• Documentation benefits from attachments in the
Common Terms used in Magnification
form of digital photography and video productions.
i. Usable power: Usable power is the maximum object • “Work satisfaction” in practice. Clinicians who
magnification that can be used in a given clinical utilize a dental microscope enjoy more during clinical
situation relative to the depth and size of the procedures due to ideal working conditions and
operative field. Increasing the magnification predictable treatment outcomes.
decreases the depth of field and narrows its size.
ii. Viewing angle: Angular position of optics allowing Disadvantages of Microscope
comfortable position of the operator. • Indirect vision with mirrors is inevitable in non-
iii. Field of view: Area visible under magnification. surgical endodontics. Left to right and right to left
iv. Depth of field: The distance between the nearest and coordination is difficult initially.
the farthest objects. • As magnification increases, the size and depth of
v. Working distance: The distance from operator’s eye field decreases and also the illumination.
to the treatment field. • Four or six handed dentistry is mandatory. The assis-
vi. Convergence angle: Aligning of two oculars pointing tant should be well trained to be able to anticipate
at the identical distance and angle to the object or and pass on the relevant instruments without the
the field. operator removing his/her eyes from the eyepiece.
vii. Declination angle: The angle of operator’s eyes that • It slows down the operator; each procedure takes
is inclined downward toward the work area is the more time to perform under the operating microscope.
declination angle. • The normal instruments are too bulky; hence smaller
sized instruments are required.
Advantages of Microscope
• Cost of the microscope and accessories.
• Detailed view of root canal intricacies enabling the • Learning takes time.
operator to be more precise.
• Multiple choices of magnification with the twist of a Parts of the Microscope
knob, from 2X to 20X.
The basic components of operating microscope include:
• Solve many traditional ergonomic problems
1. Magnification
associated with posture.
a. Eyepiece
b. Binocular
c. Magnification changers
d. Objective lens
2. Illumination
3. Accessories

1. Magnification
Microscopes can provide magnification in the range of
2X to 20X and even more. Low magnifications are
excellent for routine work having a wide field of view
and a good depth of focus. Midrange magnifications
are used for operative procedures. In endodontics, these
are known as the “working magnification”. Higher

30 Fig. 30.2 Position of the operator

magnifications are used for specific tasks such as
inspection of finer details, check resected root surfaces,
locating extra canals, retrieving separated instruments,

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 Magnification in Endodontics 531

etc. The field of view and the depth of focus is reduced. ability to focus the lens of the eyes). The ability to
Overall magnification is determined by the power of accommodate decreases with age. They also adjust for
the eyepiece, focal length of the binoculars, the refractive error (the degree to which a person needs to
magnification change factor and the focal length of the wear corrective eye glasses).
objective lens.
b. Binoculars: The function of the binoculars is to hold
The total magnification of a microscope is repre-
the eyepieces. It allows the adjustment of interpupillary
sented by the following formula:
distance. They are aligned manually or with a small
Focal length of tube knob until the two divergent circles of light combine to
Total magnification = affect a single focus. It projects an intermediate image
Focal length of object length
into focal plane of the eyepieces. As in a typical pair
× Eyepiece power × Magnification value of field binoculars, the interpupillary distance is set
by adjusting the distance between the two binocular
Magnification: Point to remember
tubes.
• If the focal length of the objective lens is increased, the
magnification and the illumination is decreased, while the
Binoculars are of different focal lengths. Longer the
field of view is increased. focal length of the binocular, the greater is the
• If the focal length of the binoculars is increased, the magnification. They are available as straight, inclined
magnification is increased and the field of view is decreased. or inclinable forms.
• If the magnification factor is increased, the magnification is i. Straight Binocular: Straight binocular is oriented
increased and the field of view is decreased. parallel to the optical axis of the microscope. They
• As the magnification increases (may be the power of eyepiece), have the advantage of allowing the use of direct
the field of view and the depth of field decreases. vision in both the arches.
ii. Inclined Binocular: Inclined binocular is off set at an
a. Eyepiece: The eyepiece is available in powers of 6.3X,
angle of 45°.
10X, 12.5X … and so on. They provide the desired
magnification of an object along with the focal length iii. Inclinable Binocular: Inclinable binocular (Fig. 30.4)
and magnification change factors. The viewing side of is adjustable for positions up to and sometimes
each eyepiece has a rubber cup, which is turned down beyond 180°. This type of binocular is most useful
if the operator wears eyeglasses (Fig. 30.3). for endodontic procedures including surgeries. It
allows the operator to look directly at the maxillary
It has adjustable diopter settings, which range from
and mandibular arches. It also provides postural
–5 to +5 and are used to adjust for accommodation (the
comfort and flexibility.
c. Magnification changers: The dental microscopes have
magnification changers (Fig. 30.5) to increase or decrease

Fig. 30.3 Eyepieces and objective lens Fig. 30.4 Inclinable binocular
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 532 Essentials of Endodontics

A 200 mm focal length and 8 inches distance is

recommended so as to have adequate room to place
surgical instruments and will be close to patients.
The dental operating microscope is focused much
like a laboratory microscope. The manual focusing
knob, which is usually located on the side of the
microscope housing, changes the distance between the
microscope and the surgical field.
Before the microscope is used, it is made parfocal
(the process of setting the focus for the entire range of
magnification for the operator). Parfocaling is operator
specific. To parfocal a microscope, a flat object is placed
under the scope and focused at the highest magnifica-
tion. The right eye/left eye diopter settings are unique
to each person and must be set individually. Once the
microscope is parfocused, accessories such as cameras
Fig. 30.5 Magnification changers and auxiliary binoculars are also adjusted accordingly.
A microscope set up should have the following
the magnification during operative procedures. These features for use in endodontic applications:
are available as 3 or 5 steps manual changers or power • 12.5x eyepiece power
zoom changers. Located in the head of the microscope,
• 125 mm inclined binocular
it consists of lenses that are mounted on a turret. This
turret is connected to a dial that is located on the side • 200 mm objective lens
of the microscope housing. The dial positions (one lens • 5-step changer, ranging from 4X to 28X.
in front of the other within the changer) produce a fixed
magnification factor. Five-step changer has a second 2. Illumination
set of lenses mounted on the turret and produce five The illumination in a microscope is from the light
fixed powers of magnification. Rotating the dial source. Three light source systems are available; 100W
reverses the lens position and produces a second xenon halogen light bulb, metal halide light source and
magnification factor. a quartz halogen bulb. The xenon light is brighter and
Power zoom changer is a series of lenses that move produces light almost comparable to daylight; whereas,
back and forth on a focusing ring to give a wide the halogen light produces a yellow picture.
range of magnification factors. Advantage of power The xenon light is better than quartz halogen, since
zoom changers is that it avoids momentary visual the fiberoptic cables of halogen absorb light and
disruption, which is common using a 3 or 5 steps have a tendency to be light deficient. Also, xenon
manual changer. projects a brighter and warmer light against bone and
soft tissues.
d. Objective lens: The focal length of the objective lens
determines the distance between the lens and the The metal halide light is a compact, powerful, and
surgical field. A variety of objective lenses are available efficient light source. It works under high pressure and
with focal lengths ranging from 100 to 400 mm temperature. Light is delivered via a high efficiency
(Table 30.4). fiberoptic illumination, thus maintaining a cool surgical
site.
The intensity of the light is controlled by a rheostat
Distance between lens and operative field vs and the lamp is cooled by a fan. The light is reflected
Table 30.4 through a condensing lens to a series of prisms and
focal length of objective lens
Focal length of Distance between lens and then through the objective lens to the surgical field.
objective lens operative field As the light illuminates the field, the reflected image
100 mm 4 inches is transmitted through the objective lens (the magnifica-
175 mm 7 inches tion changer lenses and the binoculars) as two separate

30 200 mm
400 mm
8 inches
16 inches
optical beams. The separation of the image beams
produces the stereoscopic effect necessary to assess the
depth of field.

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 Magnification in Endodontics 533

The illumination with the operating microscope is

coaxial, i.e. the light is focused between the eyepieces
in such a fashion that the clinician can look into the
surgical site without any shadow. The microscope uses
Galilean optics, which forms at infinity and send
parallel beam of light to each eye. The eye fatigue is
minimum. Loupes, on the other hand, rely on conver-
gent vision that essentially requires an overlap of two
images. This form of magnification leads to eye fatigue
soon (Fig. 30.6).
In order to document the surgical proceedings, the Fig. 30.7 Beam splitter
reflected light after splitting made available to camera
or auxiliary observation tube. This is known as ‘beam
splitter’ (Fig. 30.7). The beam splitter when inserted in
the optical pathway of the microscope splits the light
reflected from the surgical field and direct the image
to a camera and/or an auxiliary observation tube.
Depending on the split ratio, most of the light is
available for the operator. A traditional 50/50 beam
splitter contains two cube prisms. These prisms reflect
50% of the available light across the area of each prism
through partially reflective coatings. The reflected
portion of the light then goes through an iris diaphragm
to a video camera. The other 50% is transmitted across
the area of the cube prism to the primary user (Fig. 30.8).

3. Accessories
Many accessories are provided to facilitate movement
during operative procedures.

Fig. 30.8 Parallel vision created by beam splitter minimizing

eye fatigue

• Pistol grip or bicycle style handles can be attached

to bottom of the microscope to facilitate movement
of the microscope during operative procedures.
Either of these two types is essential for maneuver-
ability.
• Observer tubes (auxiliary monocular or binocular)
for assistants to see what the operator performs so
that they can assist at the same magnification. LCD
screen can also be provided for assistants.
• Camera and video adapters (Fig. 30.9) are used to
attach video and digital cameras to the beam splitters
for documentation of photographs and videos. These
adapters should have the same focal length as the

Fig. 30.6 Convergent vision leading to eye fatigue in loupes

eyepiece so that the camera can record an image with
the same magnification and field of view as that seen
by the operator.
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 534 Essentials of Endodontics

Fig. 30.9 Camera and video adapter a

Uses of Operating Microscope in Endodontics

1. Diagnosis
a. Diagnosis of caries: Magnification is essential for
diagnosing incipient dental caries (Fig. 30.10). The
initial color alteration/demineralization on the tooth
surface can only be diagnosed by microscope. High
magnification makes it possible to detect hidden caries
(microscopic signs of decay inside the crown).

b. Soft tissue evaluation: Soft tissue evaluation, in b

routine, may not require magnification. However, at Fig. 30.11a and b Identification of cracks
times, inconspicuous sinus tract can be located using
higher magnification. 2. Non-surgical Endodontic Procedures
c. Identification of cracks: The superficial fracture lines The use of microscope has revolutionized non-surgical
in the enamel are relatively undetectable with normal endodontics. The ability to visualize the root canal
vision; however, when viewed under high power, system in fine details help the operator to clean and
definite cracks can be diagnosed (Fig. 30.11a and b). shape it more efficiently. The dryness of root canal
before obturation and distribution of sealer on the wall
of the root canal during obturation can be better assessed.
The microscope is helpful in following situations:
a. Identification of anatomical landmarks: The
anatomy of pulp chamber and the anatomical
landmarks in the pulp chamber, viz. overhanging walls
of the roof of pulp chamber (Fig. 30.12), are better
viewed using microscopes. The pulp stones, if any,
are also removed in a better way using microscopes
(Fig. 30.13). The floor of the pulp chamber is a delicate
structure and is to be handled carefully. Microscopes
help in better treatment of pulp floors, which avoid
subsequent complications.
b. Location of canal orifices: The major canals are easily
located once the access cavity preparation is completed.

30 Fig. 30.10 Incipient caries

In case where the pulp chamber is obliterated with pulp
stones, it is difficult to locate the canals orifices.
Magnified views make it easier to recognize the dentin

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 Magnification in Endodontics 535

Fig. 30.14 Location of MB2 (removing dentin cover from

the orifice)

Fig. 30.12 Overhanging wall of roof of pulp chamber

Fig. 30.15 Negotiating calcified canals

d. Identification of extra canals: The variation in

morphology of the pulp spaces is not an unusual
phenomenon. The use of magnification and fiberoptic
illumination has the better chances of locating extra root
canals. The prevalence of second mesiobuccal canal in
Fig. 30.13 Pulp stones maxillary first molars has increased from 73% from the
premagnification era to 93% in the microscope era
coverage over the orifice, which can be removed (Fig. 30.16a). The identification of a middle mesial and
precisely with an ultrasonic instrument (Fig. 30.14). middle distal canal in the mandibular first molars has
c. Negotiating calcified canals: Use of magnification also improved with microscope (Fig. 30.16b and c).
along with ultrasonic troughing of the pulp chamber e. Identification of cracks and fractures: After the access
helps to identify and remove the calcifications including preparation, cracks can be detected on the floor of the
denticles. The operator can identify, which aspects of pulp chamber. Radicular cracks, which may and may
the pulp chamber walls prevent endodontic files from not extend vertically can also be identified (Fig. 30.10).
making straight line access. This ability allows for more
conservative removal of tooth structure to improve
endodontic access (Fig. 30.15).
f. Removal of pulp tissue completely: Magnification
helps in identifying pulp tissue remnants from crevices
30

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 536 Essentials of Endodontics

Fig. 30.16a Location of extra root canal

Fig. 30.17a and b Removal of pulp tissue

Fig. 30.16b Middle-mesial Fig. 30.16c Middle-distal

within the pulp chamber. Magnification can help

removing pulp remnants from root canals, ensuing a
cleaner canal (Fig. 30.17a and b).
g. Retreatment: The operating microscope has brought
significant advantages of being able to perform
successful non-surgical retreatment without the need
for surgery. Procedures such as bypassing a ledge,
removing a separated instrument or repairing a perfora- a
tion have become more predictable (Fig. 30.18a and b).
During post removal, identification of residual cement
and the remaining dentin can be better carried out using
microscope.

3. Surgical Endodontics
The operating microscope has improved the visualiza-
tion of surgical field. The operator can visualize root
and tooth anatomy in a better way and understand the

30 reasons of errors during surgical procedures. The

magnification, illumination and micro instruments
constitute a microsurgical trial.
b
Fig. 30.18a and b Perforation repaired with MTA

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 Magnification in Endodontics 537

A resected root under higher magnification easily mirrors differ from the traditional mirrors in their size
reveals anatomical details, such as isthmus, canal and shape. Smaller micro-mirrors are required since the
fins and lateral canals. The ultrasonic instruments operating field under the microscope has a limited area.
help in preparing the root-end in a precise manner A front surface mirror is preferred to eliminate the
(Fig. 30.19a and b). The differences between conventional double image distortion seen with the normal mirrors.
and microsurgery are tabulated in Table 30.5. Micro mirrors are available as round (2.0 mm, 3.0 mm,
Use of mini (micro) instruments 4.0 mm and 5.0 mm diameter), oval or rectangular
Magnification in endodontics facilitated miniaturiza- mirrors. The size and shape can be selected depending
tion of routine and surgical endodontic instruments. upon the area available at the surgical site. Mini head
The most important instrument required for micro handpieces are also available for inaccessible areas
endodontics is the micro-mirror (Fig. 30.20). These (Fig. 30.21)

a b

Fig. 30.19a and b Root-end prepared and retrograde filling

Table 30.5 Differences of conventional surgery and microsurgery

Procedure Conventional surgery Microsurgery
Identification of root apex Difficult Comparative easy
Size of osteotomy Large (more than 1.0 cm) Small (0.5 cm is sufficient)
Bevel angle Acute (45°) Shallow (10°)
Isthmus identification Very difficult Easy
Inspection of preparation Difficult Easy
Retrofilling Approximate Precise

Use of ultrasonics in combination with microscopes

The advantages of operating microscope-ultrasonic
combination are:
• Ultrasonic tips can be more effective to “move” the
coronal shaping away from furcations, flutings, and
Fig. 30.20 Micro mirrors
other high-risk anatomical sites.
• Microscopic visualization is improved because the
bulky head of a traditional handpiece is not a factor.
• Ultrasonics can be more effective and conservative
at “sweeping” the access to de-roof the chamber
• The MB2 or calcified chambers in posterior teeth rely
on a lateral, not apical, motion that benefits from the

Fig. 30.21 Mini head handpiece

micro-ultrasonic combination.
• The cleaning and shaping of the canals can be better
visualized rather than just relying on the “feel”.
30

t.me/Dr_Mouayyad_AlbtousH
 538 Essentials of Endodontics

Various ultrasonic tips are available for different 9. Donald EA. Introduction to Magnification. J Esthet. Restor.
procedures, viz. tips for removal of calcifications, tips Dent.: 2003; 15:426–439.
for root-end preparations, etc. 10. Engelke W, Leiva C, Wagner G and Beltran V. In vitro visualiza-
tion of human endodontic structures using different endoscope
4. Documentation and Patient Education systems. Int. J. Clin. Exp. Med.: 2015; 8:3234–3240.
The endodontic procedures can be videotaped using 11. Fabbro MD. Endodontic therapy using magnification devices:
camera provided with microscope. The photographic a systematic review. J. Dent.: 2010; 38:269–275.
evidence of the procedure, not only help in legal 12. Feix LM, Boijink D, Ferreira R, Wagner MH and Barletta FB.
implications, but also in patient education. The clinical Operating microscope in endodontics: Visual magnification
and radiographic features can be shown to the patient, and luminosity. South Brazilian Dent. J.: 2010; 7, 340–348.
in case some controversy arises, or for motivating the 13. Garcia A. Dental magnification: a clear view of the present
patient and family members. and a close-up view of the future. Compend. Contin. Educ.
Documentation is an important benefit of using the Dent.: 2005; 26:459–463.
dental operating microscope. In this era of evidence 14. Girsch WJ and McClammy TV. Microscopic removal of dens
based dentistry, cameras attached to the microscope invaginatus. J. Endod.: 2002; 28:336–339.
help in recording and documenting the treatment 15. Lins CC, Silva EM, Lima GA, Menezes SE and Travassos RM.
procedures. It serves three purposes: Operating microscope in endodontics: A systematic review.
• Helps to educate the patients as well as the students. Open J. Stomatology: 2013; 3:1–5.
• It is a mode of communication with the referral 16. Louis JB, Michael JB, Ellen AB and Christopher SW. Effect of
dental surgeon. magnification on locating the MB2 canal in maxillary molars.
J. Endod.: 2002; 28:324–327.
• Helps maintain legal documentation of the diagnosis
and the subsequent treatment. 17. Mamoun JS. A rationale for the use of high powered
magnification or microscopes in general dentistry. Gen. Dent.:
5. Marketing and Practice Management 2009; 57:18–26.
The photography with microscope can be utilized as a 18. Moshonov J and Nahlieli O. Endoscopy in endodontics. Alpha
marketing tool to impress upon patients and others Omegan: 2011; 104:26–34.
regarding dental procedures being carried out in the 19. Perrin P, Neuhaus KW and Lussi A. The impact of loupes
clinic. These features definitely effect growth of the and microscopes on vision in endodontics. Int. Endod. J.:
2014; 47:425–429.
practice.
20. Robinstein R. Magnification and illumination in apical
BIBLIOGRAPHY surgery. Endodontic Topics: 2005; 11:56–77.
21. Rubinstein R. The anatomy of the surgical operating
1. Bachall JK and Barss JT. Orascopy: A vision for the new microscope and operating positions. Dent. Clinic. North Am.:
millennium, part 2. Dent. Today: 1999; 18:82–85. 1997; 41:391–413.
2. Bahcall JK. Visualization in endodontics. Eur. J. Gen. Dent.:
22. Schwarze C, Baethge T, Stecher and Geurtsen W. Identifica-
2013; 2:96–101.
tion of second canals in the mesiobuccal root of maxillary
3. Bowers DJ, Glickman GN, Solomon ES and Jianing H.
first and second molars using magnifying loupes or an
Magnification’s effect on Endodontic fine motor skills. J.
Operating Microscope. Aust. Endod. J.: 2002; 28, 57–60
Endod.: 2010; 36:1135–1138.
4. Carr G. Microscopes in Endodontics: J Calif. Dent. Assoc.: 23. Takatomo Yoshioka, Chihiro Kobayashi and Hideaki Suda.
1992; 11:55–61. Detection rate of root canal orifices with a microscope. J.
Endod.: 2002; 28:452–453.
5. Cunha RS, Davini F, Fontana CE, Miguita KB and Bueno CES.
The micosonics concept: Maxillary first molar with five root 24. Valachi B. Magnification in Dentistry: How ergonomic
canals: case report. South Braz. Dent. J.: 2011; 8:231–235. features impact your health. Dent. Today: 2009; 28, 132–134.
6. De Carvalho MC and Zuolo ML. Orifice locating with a 25. Von AT, Steiner RG and Tay FR. Apical surgery: endoscopic
microscope. J. Endod.: 2000; 26:532–534. findings at the resection level of 168 consecutively treated
7. Del Fabbro M and Tascheiri S. Endodontic therapy using roots. Int. Endod. J.: 2011; 44:290–302.
magnification devices: a systematic review. J. Dent.: 2010; 26. Yoshifumi Kinomoto, Fumio Takeshige, Mikako Hayashi,
38:269–275. Shigeyuki Ebisu J. Optimal positioning for a Dental Operating
8. Dhingra A and Nagar N. Recent advances in endodontic Microscope during nonsurgical endodontics. J. Endod.: 2004;
visualization: a review. IOSR J. Dent. Med. Sci.: 2014; 13:15–20. 30:860–862.

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 Chapter
31
Lasers in Endodontics

The development of Lasers has revolutionized every undergo two possible changes, i.e. either moving to a
field of medical science, including endodontics. The higher state or being pushed back to a lower one.
investigators have been studying the effects of Lasers Normally, the first process would predominate but if
on oral hard and soft tissues. The areas of interest have the majority of molecules are already in a higher energy
been the reduction of dental caries through increased state (termed as population inversion) then the released
resistance of enamel due to alteration of enamel's photon will move in speed with the original photon.
structure, caries detection and removal, sterilization of These two photons will strike two further molecules
dental instruments, disinfection and preparation of root causing production of another two photons and the
canals, welding of orthodontic appliance and fixed vicious reaction starts. This effect is known as MASER
prosthesis, therapy for soft tissue lesions and laser (Microwave amplification by stimulated emission of
acupuncture. radiation). This principle was applied to the electro-
Laser is a device that transforms light of various magnetic waves of light and the process was called
frequencies into a chromatic radiation in the visible, LASER.
infrared and ultraviolet regions with all the waves in a
phase capable of mobilizing immense heat and power COMPONENTS OF LASER DEVICE
when focused at a close range. The laser device consists of:
Laser is acronym for ‘Light amplification by stimulated 1. Laser medium: Laser medium determines the
emission of radiation’. The concepts of stimulated wavelength of the light emitted from laser. The
emission of radiant energy, the foundational basis for names of dental lasers are based on the active
modern laser physics, were initially discussed in the medium that is to be stimulated. The active medium
literature by Einstein in 1917. The first laser was can be a gas (argon, carbon dioxide), a liquid (dyes)
constructed by Theodore Harold Maiman in 1960 using or a solid state crystal rod [neodymium: yttrium-
synthetic Ruby (aluminium oxide doped with aluminium-garnet (Nd:YAG), erbium-doped yttrium
chromium oxide). The first lasers to be marketed for aluminium garnet (Er: YAG) or a semiconductor
intraoral use were carbon dioxide lasers. The (diode lasers)].
application of lasers for endodontics was first carried 2. Optical cavity/Laser tube/Optical screen: It consists
out by Weichman and Johnson. of two mirrors, one fully reflective and other partially
transmissive; located on either end of the optical
PRINCIPLE OF LASER cavity.
If a microwave beam containing photons passes 3. Power source: The power source excites or pumps
through a cloud of ammonia gas, the gas molecules will the atoms of laser medium to their higher energy
be raised to a higher energy state as energy is absorbed. levels (Fig. 31.1).
Earlier, Einstein predicted that if a photon of correct Laser is a beam of very high intensity light. It differs
size struck a molecule already in an excited state, that from ordinary sun light and light of other sources, as
molecule would fall back to lower energy level and lamps, etc. The striking features of laser light are:
would emit a photon of exactly the same size and • Monochromatic: Radiation in which the waves have
moving in the same direction as the entering photon. single wavelength (color). Lasers are often designated
Thus, in case of ammonia gas, the molecules can by visible color, i.e. red light/green light laser.

539

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 540 Essentials of Endodontics

Fig. 31.1 The laser device

• Coherent: The waves are in a certain phase relation- Laser Emission Modes
ship to each other, both in space and time. The dental laser device can emit the light energy mainly
• Collimated (directional): The emitted waves are nearly in two modalities as a function of time (third is the
parallel and collimated; do not diverge (source even running mode):
at a distance can be focused).
• Continuous (constant on) emission: It is the continuous
• Produce intense and powerful beam of light (power
wave in which the beam is emitted at only one power
and beam quality affects this property).
level for as long as the operator depresses the foot
Laser Delivery System switch.
There are three delivery systems: • Pulsed (pushed on and off) emission: It is termed as a
• Articulated arms (with mirror at joints): For ultraviolet, gated pulse mode having periodic alterations of the
visible and infrared lasers. laser energy, much like a blinking light. This mode
• Flexible hollow waveguide: A flexible hollow wave- is achieved by the opening and closing of a
guide or tube has an interior mirror finish. The laser mechanical shutter in front of the beam pathway of
energy is reflected along this tube and it exits through a continuous wave emission. It can be super-pulsed
the handpiece at the surgical end with the beam or ultra-pulsed depending upon the timings.
striking the tissue in a non-contact fashion.
• Running pulse mode: Another mode is the running
• Glass fiberoptic cable: The third delivery system is a
pulse mode, wherein large laser energy is emitted
glass fiberoptic cable. This cable can be more pliant
for an extremely short span, followed by no laser
than the waveguide as it has a corresponding
decrease in weight and resistance to movement, and beam for a relatively long time.
is usually smaller in diameter (the delivery system The types of lasers and their mode of emission are
of choice). tabulated in Table 31.1.

Table 31.1 Types of lasers and their mode of emission

Type of laser Active medium (wavelength in nm) Mode of emission
Gas laser • Argon (488, 515) • Continuous
• Helium-Neon (633) • Continuous
• Carbon dioxide (10600, 10300, 9600) • Continuous
Solid-state laser • Nd:YAG (1064) • Continuous/pulsed
• Er:YAG (2940) • Continuous/pulsed
• Er:Cr:YAG (2780) • Continuous/pulsed
• Ho:YAG (2100)
Semiconductor laser (Diode) • Gallium-Arsenide (GaAs) (904) • Continuous/pulsed

31 •
•
Gallium-Aluminium-Arsenide (GaAlAs) (780,890)
Indium-Gallium-Aluminium Phosphide (GaAlP) (630, 700)
• Continuous/pulsed
• Continuous/pulsed

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 Lasers in Endodontics 541

Mechanism of Laser Action Table 31.2 Tissue effects with rise in temperature
The possible mechanisms of laser action can be: Tissue temperature (°C) Observed effect
• Photothermal ablation: Photothermal ablation is used 50–60°C Hyperemia
to vaporize or coagulate tissue through absorption 60°C to 100°C Protein denaturation, welding,
in a major tissue component (occurs in high powered hemolysis, coagulation, shrinkage
lasers). 100°C–150°C Water in soft and hard tissue boils
• Photomechanical ablation: It causes the disruption of (vaporization or ablation)
tissues due to a range of phenomena, such as shock 200°C–400°C Carbonization of organic material
wave formation, cavitations, etc. may occur
• Photochemical effects: Light sensitive substances are 400–1400°C Inorganic constituents melt and/or
used to treat specific tissues, such as cancer. recrystallize and may vaporize

LASER TISSUE INTERACTION d. Photomechanical and photoelectrical interactions:

These include photodisruption, photoplasmolysis
Laser tissue interaction implies interaction of photons and photoacoustic interactions. The pulse of laser
with the atoms or molecules of the target tissue. Lasers energy on the dental tissues can produce a shock
differently interact with the target tissue, depending wave (photo acoustic effect of laser light), which may
on the optical properties of the tissue. The different explode or pulverize the tissues with mechanical
ways of interaction are: energy. Photoplasmolysis describes the removal of
a. Photobiological interactions: The photobiological tissues through the formation of electrically charged
interactions are of four types: ions.
i. Absorption: The desired interaction is the absorption
Classification
of laser energy by the intended target tissue. This
amount of energy that is absorbed by the tissue Lasers have been classified depending upon the
depends on the tissue characteristics, such as following features:
pigmentation (melanin of skin, hair and hemo- 1. According to wavelength
globin in blood), proteins and water content; and a. Excimer laser (wavelength 150–350 nm)
also on the laser wavelength and emission mode.
b. Visible light laser (wavelength 350–750 nm)
Argon has a high affinity for melanin and hemo-
globin in soft tissue. • Ruby laser
ii. Transmission: This interaction is inverse of absorp- • Argon laser
tion; transmission of laser energy directly through • Helium-neon laser
the tissue without effecting it. c. Infrared laser (wavelength 750–12000 nm)
iii. Reflection: The incident laser beam redirects itself • Neodymium: Yttrium-aluminium-garnet
without affecting the target tissues. (Nd:YAG)
iv. Scattering: Scattering of the reflected light weakens
• Holmium: Yttrium aluminium garnet (Ho:YAG)
the intended energy and possibly produces no
useful biologic effect; may transfer heat to the • Erbium-doped yttrium aluminium garnet
adjacent tissues. (Er:YAG)
• Carbon dioxide laser
b. Photochemical interactions: The basic principle of
photochemical process is that specific wavelength 2. According to the type of laser medium
of laser light is absorbed by naturally occurring a. Gas laser (argon, helium-neon, carbon dioxide)
chromophores (tissue compounds), which are able to b. Solid-state laser (Nd:YAG, Er:YAG, Er:Cr:YAG,
induce certain biochemical reactions. Photosensitive Ho:YAG)
compounds, when exposed to laser energy, can produce
a single oxygen radical for disinfection of the root c. Semiconductor laser (Gallium-Arsenide, Gallium-
canals. Aluminium-Arsenide, Indium-Gallium-Aluminium-
Phosphide)
c. Photothermal interactions: The radiant energy
3. According to tissues to be lased
absorbed by tissue substances are transformed into heat
energy, which then produces the requisite effects
(Table 31.2).
a. Soft tissue laser
b. Hard tissue laser
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 542 Essentials of Endodontics

4. According to potential hazards, lasers are classified permissible emission limit (AEL) for continuum laser
according to American National Standard Institute’s is 0.5W and wavelength 400–700 nm.
safety norms. Class 4: Lasers exceeding 3B level of AEL; mostly unsafe
• Class I: Do not pose a health hazard; inherently for eyes and skin.
safe for eyes and skin (e.g. laser printers).
• Class II: Emit only visible light with low power TYPES OF LASERS
output (1.0 mW) and do not normally pose a
hazard because of the normal blinking (aversion a. Soft Tissue Lasers
reactions) of eye, e.g. surgical laser [continuous The soft tissue lasers are athermic, low energy lasers
staring should be avoided; staring more than that generally utilize the semiconductor laser diodes.
10000 seconds produce burning in retina; e.g. Their wavelength stimulates cellular activity. They aid
commercial laser scanner (referred to as class IIa)]. in tissue regeneration and wound healing by increasing
• Class III: collagen production by fibroblast stimulation (Figs 31.2
– Class IIIa: Any wavelength and output power and 31.3). Soft tissue lasers are used to relieve pain,
less than 5 mW of visible light. It will not harm inflammation, edema and also accelerate healing.
the unprotected eye within the blinking reflex
(one-fourth of a second) period (e.g. laser
printers).
– Class IIIb: Can produce a hazard to the un-
protected eye if viewed directly/from reflective
light. Power output 500 mW (e.g. diode laser
cutter).
• Class IV: Extremely hazardous from direct viewing
where the laser power is above 500 mW (e.g. lasers
used in surgery).
This classification was accepted till 2002 and is
designated as ‘old classification’. The classification is
modified now including concepts of ‘maximum
permissible exposure’ (MPE) (The highest power or
energy density, i.e. W/cm2 of a laser source that is
considered safe) and the ‘accessible emission limit’
(AEL) (the maximum power or energy, which can be Fig. 31.2 Soft tissue laser by DEKA
emitted in a specified wavelength range and exposure
time that passes at a specific distance).
The modified classification
Class 1: Safe under all conditions; maximum permissible
exposure (MPE) cannot be exceeded when viewing a
laser with naked eye or with microscope.
Class 1M: Safe under all conditions, except when passed
through microscopes and telescopes.
Class 2: Safe because of blink reflex; applies to visible-
light lasers (400–700 nm). Laser pointers and measuring
instruments are in class 2.
Class 2M: Safe because of blink reflex, if not viewed
through optical instruments.
Class 3R: Visible continuous lasers are limited to 5 mW
(for pulsed lasers, this limit varies). 3R is considered
safe with restricted beam viewing.
31 Class 3B: 3B laser is hazardous if exposed directly
(direct viewing need protective eyewear). The accessible Fig. 31.3 Diode soft laser

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 Lasers in Endodontics 543

In dentistry, soft tissue lasers are used for: • Neodymium: Yttrium aluminium garnet (Nd:YAG
• Desensitization of hypersensitive dentin laser)
• Healing of dry socket The routinely used Lasers are described:
• Reducing pain and promoting healing of ulcers, etc.
a. Carbon Dioxide (CO2) Laser
The examples of soft tissue Lasers are:
• Helium – Neon (He-Ne) Carbon dioxide laser (active medium CO2 and nitrogen)
• Gallium – Arsenide (Ga-Ar) produces a beam of infrared light centering in 9.4 μm
to 10.6 μm (Fig. 31.5). CO2 laser was thought to be
• Gallium – Aluminium–Arsenide (Ga-Al-Ar)
suitable for selected surface applications on teeth, such
b. Hard Tissue Lasers as sealing of pit and fissures, welding of ceramic
materials to enamel and prevention of dental caries.
The hard tissue lasers are thermic and of high energy,
However, generating extremely high surface tempera-
that are utilized in surgery as precise energy source,
tures and inability of the beam to be transmitted via a
i.e. cut, coagulate and vaporize (Fig. 31.4a and b). These
fiberoptic cable to a handpiece limited its use for
are mostly used for caries removal, cavity preparation
above applications. As principally absorbed by water
and etching of enamel and cementum surfaces.
molecules, it can cut many hard and soft tissues (used
The examples of hard tissue lasers are: both for hard tissues ablation and soft tissue surgeries).
• Argon The wavelength has the highest absorption in hydroxy-
• Carbon dioxide apatite out of any dental laser. Therefore, structures
adjacent to surgical site must be shielded from laser
beam.

Advantages
• Excellent hemostasis, reduce bacteremia
• Minimum postoperative pain/discomfort
• Remove tissue quickly and efficiently
• Minimize mechanical trauma

Disadvantages
• Lack of feed back (CO2 laser used in a non-contact
mode)
• Black-brown pigmentation of the treated tissues
• Costly

Fig. 31.4a Hard tissue laser (BIOLASE)

Fig. 31.4b Radial firing tip used with BIOLASE Fig. 31.5 Carbon dioxide laser
31

t.me/Dr_Mouayyad_AlbtousH
 544 Essentials of Endodontics

b. Argon Laser as well as carious decay without causing any thermal

The argon laser uses argon gas as the active medium, injury to adjacent tissues. Restorative materials like
which generate coherent visible light with primary wave- composites and cements can be ablated without using
lengths of 488 and 514 nm. The 488 nm (blue color) mechanical bur. Gold crowns and cast fillings cannot
wavelength emission is for activating camphoroquine be removed because the laser beam is reflected by
during polymerization of composites. The 514 nm (blue metals. No ablation effect is observed on ceramics. This
green color) light wavelengths have peak absorption laser is recommended for osteotomy, cyst removal and
in red pigment such as hemoglobin; thus, laser light is apicoectomy because of bone healing properties.
well absorbed in pigmented tissues with abundance of The thermal side effects are greatly reduced with
hemoglobin, hemosiderin and melanin. Argon laser Er:YAG laser. However, this laser beam is not easily
light is not well absorbed by enamel and dentin or transmitted through optical fibers and therefore is
other non-pigmented tissues. These characteristics usually applied via mirror and arm delivery systems.
make argon laser very useful for cutting, vaporizing, A root canal preparation is not possible due to lack of
coagulating and providing hemostasis on gingival and suitable delivery system (Fig. 31.6 a and b).
oral mucosa. The argon laser is primarily used for root
planing and curettage, gingival retraction, gingivec-
tomy/gingivoplasty, frenectomy, treatment of oral
lesions, tissue welding and for caries detection.
c. Neodymium: Yttrium Aluminium Garnet
(Nd:YAG) Laser
Nd:YAG laser systems are usually large and bulky. This
system emits its pulsed energy at 1064 nm (near
infrared) and this energy is directed through a 320 μ
silica fiber, using the high peak powers and free running
pulse emission. When this beam is used in non-contact,
defocused mode, this can penetrate deep and is used
for hemostasis, treatment of aphthous ulcers or pulpal
analgesia. The main disadvantage is the direct exposure
of pulp by laser light through crown or root, leading to
denaturation of pulp tissues. The common clinical
Fig. 31.6a Fotona Fidelis (screen projection)
applications are for cutting and coagulation of the
dental soft tissues. It has an affinity for pigmented
tissues (more for melanin and less for hemoglobin). It
minimizes the heat build-up in tissues.
d. Erbium Laser
Erbium laser is a promising laser system because of its
emission wavelength (Er:YAG—2940 nm and
Er:Cr:YAG—2780 nm), which coincides with main
absorption peak of water, resulting in good absorption
in all biologic tissues including enamel and dentin.
Infrared laser systems like carbon dioxide or Nd:YAG
laser have reported the presence of zones of carboniza-
tion and necrosis due to high temperatures. In contrast,
Er:YAG laser treatment does not induce any thermal
changes. Water has a very high absorption for Er:YAG
laser light. The incident laser radiation is absorbed
in a thin surface layer causing sudden heating and
vaporization of water. A high steam pressure then leads
to micro-explosions with erupting particles. Because the
tissue is not vaporized completely but only disintegrated

31 into fragments, radiant energy is converted into ablation

that alters the morphological structure of tissue. Er:YAG
laser can be used for the removal of healthy hard tissue
Fig. 31.6b Fotona Fidelis—dual wavelength dental laser
Er:YAG and Nd:YAG

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 Lasers in Endodontics 545

e. Semiconductor/Diode Laser Advantages of laser

Gallium-Arsenide (GaAs) 904 nm, Gallium-Aluminium- • Interaction with diseased tissue is selective and
Arsenide (GaAlAs) 780–890 nm and Indium-Gallium- precise
Aluminium Phosphide (InGaAlP) 630–700 nm are the • Damage to surrounding tissues is minimum
common diode lasers (Fig. 31.7). In diode lasers, the • Easy osseous tissue removal and contouring
active medium is sandwiched between silicon wafers. • Provide good hemostasis
The discharge of current from one silicone wafer to • Help reduction in pain
another releases photons from the active medium. • Minimal need for anesthesia
Diode lasers are used for the treatment of dentin • No whining sound or vibration of dental drill
hypersensitivity, wound healing and for relieving post- • Less chair time
surgical pain.
• Fast healing
Laser type, wavelength and their clinical potential
• Less antibiotics and analgesics required
are summarized in Table 31.3.
Disadvantages of laser
• High cost
• Delivery systems are bulky
• Difficult access to the surgical area
• Air embolisms may be produced by air and water
• Precise selection of wavelength is mandatory for
different procedures

APPLICATION OF LASER TECHNOLOGY

IN ENDODONTICS
The rapid development of laser technology coupled
with better understanding of interactions with biological
tissues, has widened the scope of applying this techno-
logy in endodontics.
In endodontics, laser energy is being tried in the
following procedures:
i. Analgesia
ii. Reducing permeability of dentin and fusing dentin
plug at apical end
iii. Sterilization of endodontic instruments
iv. Pulp testing (assessment of flow of pulpal blood
Fig. 31.7 Different wavelength diode laser by laser Doppler flowmetry)

Table 31.3 Laser type, wavelength and their clinical potential

Medium Wavelength (nm) Enamel surface characteristics Clinical use
Carbon dioxide 10,600 • Surface fusion • Resin bonding
• Charring/cracking • Enamel etching
• Roughness • Caries reduction
• Partially fused crystallization
Argon 514 • Reflection of beam produces minimal • Resin polymerization
effect on surface
Er:YAG 2940 • Etched and flaky, rough surface • Cavity preparation
• Enamel etching
Nd:YAG 1,064 • Reflection of beam is seen, until photo- • Removal of debris
absorptive is placed • Enamel etching
Diode/semiconductor 630–890 • Slight etching, smooth, lacking in charring,
planed enamel prisms
• Cavity preparation
• Enamel etching 31

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 546 Essentials of Endodontics

v. Pulp capping and pulpotomy

vi. Preparation of access cavities and root canal walls
vii. Disinfection of root canals
viii. Obturation of root canals
ix. Removing gutta-percha and separated instruments
x. Endodontic surgery
xi. Endodontic mishaps
xii. Laser bleaching
xiii. Stimulate healing and relieving postoperative pain
xiv. Retrograde cavity preparation

i. Analgesia
Certain wavelengths of laser energy interfere with the
sodium pump mechanism, change cell membrane
permeability, alter temporarily the endings of sensory Fig. 31.8b Laser irradiation for treating dentin hypersensitivity
neurons and block depolarization of C and Aδ fibers of in cervical abrasions
the nerves. The pulsed Nd:YAG laser has been success-
fully used for achieving analgesia. sterilization of endodontic instruments by lasers.
Carbon dioxide, argon and Nd:YAG lasers effectively
ii. Reducing Permeability of Dentin sterilize the instruments used in endodontics.
and Fusing Dentin at Apical End
It is established that the laser irradiation of 10 pulses/ iv. Pulp Testing (Assessment of Flow of Pulpal Blood
second for two minutes on dentin melts normal dentinal by Laser Doppler Flowmetry)
surface and closes the exposed dentinal tubule orifices Laser Doppler flowmetry is a non-invasive technique
without creating any surface cracks (Fig. 31.8a and b). that detects net red blood cell movement in small
The dentin surface after Nd:YAG laser treatment showed volumes of a tissue and monitor the total blood flow
no protrusive rods (protrusive rods are a measure of through that tissue (Fig. 31.9).
open dentinal tubules). Lasers can effectively treat dentin It utilizes light beam from a He-Ne laser (632.8 nm),
hypersensitivity. The laser treatment is also effective in which is carried to and from the tissues by a fiberoptic
fusing the dentin at the apical end. probe that carries light by one fiber and receives back
the scattered light (by moving red cells which undergo
iii. Sterilization of Endodontic Instruments frequency shift according to the Doppler principle) by
A significant reduction in the microbial loads due to another fiber to the instrument (Fig. 31.10).
raised temperatures has been reported after the Details of the technique are described in Chapter 9.

31 Fig. 31.8a Laser irradiation for treating dentin hyper-

sensitivity in cervical abrasions Fig. 31.9 He-Ne laser used for pulp testing

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 Lasers in Endodontics 547

The Nd:YAG laser and formocresol tooth pulpo-

tomies, when compared at 6th and 12th week of post-
operative period, depicted no significant differences in
radiological findings. Histologically, the frequency of
dentin bridge formation was higher for laser group than
formocresol group.

vi. Preparation of Access Cavities

and Root Canal walls
Various Lasers in different forms have been tried for
preparation of access cavities and root canal walls
Fig. 31.10 Frequency shift (laser Doppler flowmetry) (Er:Cr:YSGG—2780 nm, Er:YAG—2940 nm). The root
canals prepared with Lasers are cleaner as compared
Lasers (Nd:YAG) has also been used to differentially to conventional techniques.
diagnose types of pulpitis from normal pulp.
Technique
v. Pulp Capping and Pulpotomy The apical region of canal is initially hand instrumented
with a No. 15 K-file. The laser energy set at 150 mJ
Practically, all types of lasers have been used in pulp
through fiberoptic was inserted into root canal up to
treatment procedures, especially in deciduous and
working length. The canal is prepared circumferentially
young permanent teeth. For direct pulp capping, an
in apical third, middle third and the coronal third,
energy level of 1 W at 0.1 second exposure time with
sequentially increasing the size, as required.
one second pulse intervals is applied until the exposed
pulps are completely sealed. The laser preparation shows remarkable cleanliness
of all canals. The dentin reveals a crusty, wavy aspect
For indirect pulp capping, reduction in the permea-
with open tubules and no apparent smear layer;
bility of dentin is achieved by sealing the dentinal
however, carbonization has been observed in irradiated
tubules using Nd:YAG and carbon dioxide lasers. The
root canals.
energy is well absorbed by the hydroxyapatite of
enamel and dentin, causing tissue ablation, melting and The Er:YAG laser is equally effective for debris
re-solidification. removal, producing a cleaner surface with a higher
number of open tubules compared to other lasers.
It is established that laser therapy stimulates
odontoblast activity (calcium and collagen production), Nd:YAG laser may present melted and recrystallized
leading to secondary dentin formation. Carbon dioxide dentin and smear layer removal. Argon laser irradiation
laser has been very effective in pulp treatment of root canal system also efficiently removes intracanal
procedures. It sterilizes and heals the irradiated area, debris. Recently, Xe-Cl (308 nm) Excimer laser
reduce inflammation and the size of blood clot, ensuring effectively lead to melting and lasing dentinal tubules.
close contact of the pulp with the capping materials
Photon Induced Photoacoustic Streaming (PIPS)
(fast mode for hemostasis, disinfection and sealing of
Technology
exposed pulp tissue).
Nd:YAG, Er:YAG and Er:Cr:YAG have also been It is a revolutionary method for cleaning and debriding
tried successfully in pulp capping and pulpotomies. the root canal system using Er:YAG laser energy at sub-
These are equally effective in hemostasis and ablative power levels.
coagulation of exposed pulp. Photon induced photoacoustic streaming (PIPS)
The factors rationalizing the effect of lasers on pulp harness the power of the Er:YAG laser to create
are: photoacoustic shock waves within the cleaning/
debriding solutions (sodium hypochlorite, distilled
• The bactericidal effect of laser creates a sterile area
water, EDTA, etc.) introduced in the root canal. The
over exposed pulp.
shock waves effectively stream the solutions through
• Facilitates sealing of exposed pulp. the entire canal system. The canals are left clean and
• The coagulating effect provides dry area with no the dentinal tubules are free of smear layer. Photon
bleeding.
• Controlled thermal effects of laser allow formation
of barrier against contamination.
induced photoacoustic streaming (PIPS) is equally
effective for final rinsing prior to obturation (Fig. 31.11a
to d).
31

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 548 Essentials of Endodontics

a b c d
Fig. 31.11a to d PIPS technology (Web-photo)

PIPS technology eliminates the need to introduce the have confirmed the efficacy of diode and Nd:YAG lasers
tip into the root canals. Unlike traditional laser in eradicating bacterial load from the root canals;
techniques (placement of tip at 1.0–5.0 mm from apical however, a few authors have cautioned the undesirable
constriction), PIPS tip is placed at the coronal chamber, thermal effects of root dentin. An average of 34%
allowing acoustic waves to spread into the root canals. decrease in colony forming units (CFU) for Actinomyces
A combination of laser wavelength is being used in and 15.7% for Pseudomonas aeruginosa with 5 Hz laser
twinlight endodontic treatment (TET). The authors used treatment and a decrease of 77.4% for Actinomyces and
deep penetrating Nd:YAG laser wavelength for deep 85.8% for Pseudomonas with 10 Hz laser have been
thermal disinfection and better absorbed wavelength reported. It is further documented that Nd:YAG laser
for non-thermal acoustic cleaning of root canal system. is significantly more bactericidal than other lasers
The procedure facilitates clean canals with open (Fig. 31.12a to c).
dentinal tubules free of smear layer. Photoactivation disinfection (PAD)/light activated
disinfection (LAD)/photodynamic antimicrobial
vii. Disinfection of Root Canals chemotherapy (PACT) work on the principle that
The efficacy of Nd:YAG laser in sterilizing contami- photosensitive molecules get attached to the membrane
nated root canals has been established. Various studies of the bacteria. The specific wavelength of laser

31 a b c

Fig. 31.12a to c Disinfection of root canals using Nd:YAG laser

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 Lasers in Endodontics 549

irradiation leads to the production of singlet oxygen, The advantages of using lasers in endodontic surgery
which may cause bacterial cell wall to rupture, killing are:
the bacteria. Virtually, all kinds of micro-organisms can • Effective hemostasis by sealing the blood vessels.
be inactivated by this technology (specifically gram-
positive pathogens are more sensitive than gram- • Minimal postoperative pain due to minimum tissue
negative pathogens). It is established that this technique damage and sealing off nerve endings.
effectively destroys bacteria remaining in the canal
spaces after using conventional irrigants in root canal
treatment.

viii. Obturation of Root Canal Spaces

Argon laser has been used as a heat source to compact
the gutta-percha during root canal obturation. The quality
of apical seal achieved has not been established yet.

ix. Removing Gutta-percha

and Separated Instruments
Nd:YAG laser has successfully used to remove gutta-
percha and broken files from the root canals. Nd:YAG
and Er:YAG lasers are effective in removing zinc oxide
sealers and other filling materials. Biolase laser is used
to remove gutta-percha and other filling materials
following the hydrokinetic process. It involves removal a
of tissues with laser-energized water droplets.
Hydrokinetic energy is produced by combining a spray
of atomized water with laser energy. The resulting
energy gently and precisely removes a wide range of
materials and human tissue.

x. Endodontic Surgery
Lasers have been tried in endodontic surgery to
irradiate the surgical site during apicoectomy. It
effectively achieves hemostasis and visualization of the
operating field. Laser has also been used for
biostimulation of abscess (Fig. 31.13a and b). Er:YAG
laser in a low-output power, when used in apical
surgery (Fig. 31.14a and b), lead to smooth and clean
surface devoid of charring. Diode lasers have been tried b
to improve healing at the surgical sites. Fig. 31.13a and b Biostimulation of abscess

a b

Fig. 31.14a and b Laser (Er:YAG) used in endodontic surgery

31

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 550 Essentials of Endodontics

• Clean incision resulting in minimal edema and

scarring.
• During surgery for malignancies, no danger of
splattering blood and lymph.
• Many surgical procedures can be carried out without
local anesthesia. The procedure is not painful because
laser pulse is shorter than time required for trans-
mission by nerves.
• Leave a dry and sterile field.
• Precisely interact with diseased tissues
• Reduce the amount of bacteria in the surgical field
• Easy osseous tissue removal and contouring

xi. Endodontic Mishaps

Accidental perforation of pulp chamber is a common
feature during tooth preparations. Such perforations Fig. 31.15 Laser bleaching
may occur anywhere along the root during endodontic
procedures.
Lasers have been tried to sterilize the affected area
and seal the perforation effectively. Nd:YAG laser has
been observed to be effective in disinfecting the area of
perforation and removing the attached organic/
inorganic smear layer followed by sealing the area with
laser irradiated composites.
Nd:YAG laser was tried to seal the vertical root
fracture fragments and other cracks. The crack surfaces
were filled with tricalcium phosphate and melted by
the laser irradiation (various studies confirmed the
presence of tricalcium phosphate along the crack lines).
A few authors have successfully tried melting bioactive
glass paste over the crack site using carbon dioxide laser
(higher temperature of laser could melt bioactive glass
paste in a very short span of time).
Fig. 31.16 Laser on surgical site for healing
xii. Laser Bleaching
The procedure utilizes 30–35% hydrogen peroxide, has got a stimulating action on bone morphogenic
which is usually applicable in routine bleaching. Laser proteins, which further stimulates undifferentiated
whitening gel has a unique mix of thermal absorption mesenchymal cells into osteoblasts, resulting in
crystals integrated into gel of highly processed fumed increased osteogenesis. Laser also stimulate fibro-
silica and 35% hydrogen peroxide. Bleaching gel is blasts for more collagen production, accelerate cell
applied and is activated by high intensity light source reproduction and also cause increased prostaglandin
or plasma arc light. Crystals in gel absorb thermal levels, which help in healing and regeneration of tissues
energy from light allowing better dissociation of oxygen (Fig. 31.16).
and easy penetration into the enamel matrix thus
increasing the lightening effect on teeth (Fig. 31.15). xiv. Retrograde Cavity Preparation
Er:YSGG and Cr:YSGG laser have been used for root-
xiii. Stimulate Healing and relieving Postoperative end cavity preparation. The root-surface cracking
Pain
31
that produced by ultrasonic retropreparation tips/
Laser causes an anti-inflammatory effect in the irradiated conventional preparation using a bur have been
area, which accelerates healing and decreases pain. It overcome by lasers (Fig. 31.17).

t.me/Dr_Mouayyad_AlbtousH
 Lasers in Endodontics 551

by denaturation of cellular enzyme and structural

proteins, which interrupts basic metabolic processes.
Factors affecting laser-tissue interaction are:
• Relative absorption and transmission of particular
wavelength.
• Pulse duration and pulse repetition rate.
• Level of radiation exposure.
• Relative degree of vascularity of tissue.
The deleterious effects of lasers on enamel and dentin
are as follows:
• Enamel exhibits gross cratering from 0.1 to 1.1 mm
deep depending on amount of energy delivered to
target area. In deeper penetration, dark speckling of
exposed dentin can be seen. Examination under
Fig. 31.17 Retrograde cavity prepared by laser polarized light may show crystallographic changes.
• Dentin shows shallow, irregular craters 0.1 mm deep.
LASER HAZARDS Three distinct zones of dentinal destruction are:
Lasers, although beneficial in endodontics, may have Central zone of complete dentinal destruction; an
certain hazards in clinics. The hazards can be: immediate surrounding area of partial dentinal
a. Ocular injuries destruction and a scattered zone of dark specks
b. Tissue damage beyond first two zones.
c. Environmental hazards
c. Environmental Hazards
d. Electrical hazards
Airborne contaminants can be emitted in the form of
a. Ocular Injuries smoke or plume generated through thermal interaction
Potential injury to the eye can occur either by direct of laser with tissue or through accidental escape of toxic
emission from laser or by reflection from a specular chemical and gases from laser itself. These airborne
surface. The primary ocular injury that may result from contaminants may damage the functioning of respira-
a laser accident is a retinal or corneal damage. Retinal tory system.
injury is possible with emissions in the visible (400– d. Electrical Hazards
780 nm) and near infrared (780–1400 nm) wavelengths.
Because laser use high currents and high voltage power
The effects of different wavelength of Lasers on eyes
supplies, these are potentially hazardous. Electrical
are summarized in Table 31.4.
hazards of lasers can be grouped as electrical shock
b. Tissue Damage hazards, electrical fire hazards or explosion hazards.
Laser induces damage to skin and other tissues as a
result from thermal interaction of radiant energy with LASER SAFETY
tissue proteins. Temperature elevation of 21°C above It is established that even small amount of laser light
normal body temperature can produce cell destruction can lead to eye injuries. Laser safety designs utilize
implementation of laser to minimize the risk of laser
Table 31.4 Laser wavelength and pathological effect on eyes accidents, especially involving skin and eyes. American
Wavelength (nm) Effect on eyes National Standard Institute (ANSI) provides control
180–315 (ultraviolet) Inflammation of the cornea (like measures for laser hazards. The maximum permissible
sunburn) exposure (MPE) limit should strictly be looked into
315–400 (ultraviolet) Clouding of eye lens prior to use of lasers.
400–780 (visible) Retinal burn (photochemical ANSI has provided guidance for the use of lasers in
damage to retina) a series, ANSI 136. The standard protocol is:
780–1400 (near infrared) Retinal burn; cataract 136.1: Safe use of lasers
1400–3000 (infrared)
3000 and above
Cataract, corneal burn
Corneal burn
136.2: Safe use of optical fibers and LED sources
136.3: Safe use of lasers in health care
31

t.me/Dr_Mouayyad_AlbtousH
 552 Essentials of Endodontics

136.4: Laser safety measurements for hazard evaluation 8. Enwemeka CS, Parker JC, Dowdy DS, Harkness EE, Sanford
LE and Woodruff LD. The efficacy of low-power lasers in
136.5: Safe use of lasers in educational institutions tissue repair and pain control: A meta-analysis study.
136.6: Safe use of lasers outdoors Photomed. Laser Surg.: 2004; 22:323–329.
136.7: Labelling laser protective equipment 9. Gutknecht N. Lasres in Endodontics. J. Laser and Health
Acad.: 2008; 4:1–5.
136.8: Lasers in research and development 10. Kimura Y, Yonaga K, Yokoyama K, Kinoshita J, Ogata Y and
136.9: Lasers in manufacturing environment Matsumoto K. Root surface temperature increase during
Er:YAG laser irradiation of root canals. J. Endod.: 2002;
Safety Measures 28:76-78.
• A laser warning signal outside the clinic (aware of 11. Linc CH, Chou TM and Chen JH. Evaluation of effect of laser
the risks). tooth whitening. Int. J. Prosthodont.: 2008; 21:415–418.
• Use of barriers within the operatory. 12. Marcelo TS, Bocangel JS and Nogueria GEC. SEM evaluation
of interaction pattern between dentin and resin after cavity
• Use of eyewear to protect against reflected laser light preparation using Er:YAG laser. J. Dent.: 2003; 31:127.
or accidental direct exposure (high intensity beams
13. Marchesan MA. Effects of 980-nanometer diode laser on root
should be guided through opaque tubes). canal permeability after dentin treatment with different
• The residue left after tissue ablation should be chemical solutions. J. Endod.: 2008; 34:721–724.
evacuated using high volume suction. 14. Mathew A, Lajevardi M, Al Juboori HA. An in vivo study on
• Equipment should be serviced and checked regularly comparison of disinfection of root canal with chemical
(high temperature and fire hazards may result from disinfectants and disinfectant-diode laser-photodynamic
operation of high powered lasers). treatment combined system. J. Dent. Lasers: 2015; 9:2–10.
• The operator should take adequate precautions to 15. Meire M and De Moor R. Laser disinfection, an added value?
prevent injury/damage to adjacent soft and hard Endod. Pract. Today: 2007; 1:159–172.
tissue (alignment of beams and optical components 16. Nishad SG, Thyath MN, Sharma M and Zaidi I. Laser in
should be performed at a reduced beam power). Endodontics. J. Adv. Med. Dent. Sci. Res.: 2015; 3:137–141.
Everyone uses laser should be aware of the risks 17. Norberto Batista de Faria-Junior. Evaluation of ultrasonic and
involved. The routine complacency dealing with ErCr:YSGG laser retrograde cavity preparation. J. Endod.:
2009; 35:741–744.
invisible risks can lead to health hazards, which should
be avoided following safety measures. 18. Pawar SS, Pujar MA, Makandar SD and Khaiser MI. Post-
endodontic treatment pain management with low-level laser
therapy. J. Dent. Lasers: 2014; 2:60–63.
BIBLIOGRAPHY 19. Qian-qian W. Evaluation of bactericidal effect of Er, Cr:YSGG
and Nd:YAG lasers in experimentally infected root canals. J.
1. Andrew LS. DiagnoDent laser fluorescence assessment of
Endod.: 2007; 33:830–832.
endodontic infection. J. Endod.: 2009; 35:1404–1407.
20. Roy G and Ian AM. Laser activation of endodontic irrigants
2. Attrill DC, Davies RM and King TA. Thermal effects of Er:YAG with improved conical laser fiber tips for removing smear
laser on simulated dental pulp: a quantitative evaluation of layer in apical third of root canal. J. Endod.: 2008; 34:
effects of water spray. J. Dent.: 2004; 32:35–40. 1524–1527.
3. Benedicenti S, Cassanelli C, Signore A, Ravera G and Angiero 21. Roy G. Lasers in dentistry—Review. Int. J. Dent. Clinics.:
F. Decontamination of root canals with the gallium- 2009; 1:13–19.
aluminium-arsenide laser: An in vitro study. Photomed. Laser
22. Shoj S and Nakamana M. Histopathological changes in dental
Surg.: 2008; 26:367–70.
pulp irradiated by CO2 laser; a preliminary report on laser
4. Cankat K and Recep O. Comparative evaluation of Nd:YAG pulpotomy. J. Endod.: 1985; 11:379–384.
laser and fluoride varnish for treatment of dentin 23. Viducic D. Removal of gutta-percha from root canals using
hypersensitivity. J. Endod.: 2009; 35:971–974. Nd:YAG laser. Int. Endod. J.: 2003; 36:670–673.
5. Chaudhary S, Yadav S, Oberoi G, Talwar S and Verma M. 24. Wang HL, Bor SL and Hsin CL. Morphological study of
Evaluation of root-end cavity preparation using erbium, Nd:YAG laser usage in treatment of dentinal hypersensitivity.
chromium:yttrium, scandium, gallium, and garnet laser, J. Endod. 2004; 30:131–134.
ultrasonic retrotips, and conventional burs. J. Dent. Lasers:
25. Wong WS and Rosenberg PA. A comparison of apical seals
2016; 10:43–46.
achieved using retrograde amalgam and Nd:YAG laser. J.
6. Claudio HV. Obturation of root canal system treated by Cr, Endod.: 1994; 20:595–597.

31
Er:YSGG laser irradiation. J. Endod.: 2007; 33:1091–1093. 26. Yuichir N. Effect of Er:YAG laser irradiation on biofilm-
7. Daniel HP. CO2, Er:YAG and Nd:YAG lasers in endodontic forming bacteria associated with endodontic pathogens in-
surgery. J. Appl. Oral Sci.: 2009; 17:596–599. vitro. J. Endod.: 2008; 34:826–829.

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 Chapter
32
Surgical Endodontics

Endodontic surgery refers to the removal of tissues The absolute contraindication is:
other than the contents of root canal space, before or • Where the tooth cannot be restored or saved to serve
after root canal treatment. Surgical intervention using the functions.
advanced technologies coupled with availability of better The relative contraindications are:
diagnostic aids has led to greater success in retaining a
Medical conditions
tooth with pulpal and/or periapical involvement.
• Patients with uncontrolled diabetes mellitus,
The most common endodontic surgical procedures
tuberculosis, nephritis, etc.
are periradicular curettage and apicoectomy (root end
resection). Other procedures include crown lengthening, • Active leukemia with neutropenia
replantation/intentional replantation, hemisection/ • Recent cardiac/tumor surgery
radisectomy, incision/drainage and perforation repair. • Immunocompromised patients
The surgical intervention should be selective in the • Uncontrolled hypertension
best interest of the patients. • Bleeding disorders
• Radiation therapy of face (within six months)
Indications • First trimester and third trimester of pregnancy
• Need for surgical drainage • Psychologically distressed patients
• Failed nonsurgical endodontic treatment Anatomic considerations
– Irretrievable root canal filling material • Proximity of roots to nasal floor, maxillary sinus,
– Irretrievable intraradicular post mandibular canal or mental foramen
• Calcific metamorphosis of the pulp space • Inadequate visual and mechanical access such as
• Procedural errors thick buccal plate and lingually inclined roots in
– Instrument separation mandibular second molars
– Non-negotiable ledges Skill and experience
– Root perforation(s) • The skill and experience of the operator is mandatory
– Symptomatic overfilling to carry out surgical procedures
• Anatomic variations
Classification of Surgical Endodontic Procedures
– Root dilacerations
– Apical root fenestration I. Periradicular surgery
• Curettage
• Corrective surgery
• Apicoectomy (root end resection)
– Hemisection/bicuspidization/radisectomy II. Fistulative surgery
• Replacement surgery • Incision and drainage
– Replantation/intentional replantation • Trephination
– Autotransplants • Decompression
III. Corrective surgery
Contraindications • Perforation repair
The contraindications for surgery are mostly relative • Replantation/intentional replantation
and not absolute. IV. Biopsy

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PREOPERATIVE ASSESSMENT and general health of the patient. The medical ailments
Preoperative assessment involves following features. influencing surgical procedures are:
• Cardiovascular diseases
Patient Considerations • Metabolic/hepatic disorders
The type of procedures planned for the patient and • Bleeding disorders
health status of patient must be noted. Healthy patients • Drug allergies
tolerate a surgical procedure better than medically • Respiratory problems
compromised patients. A thorough medical history and • Renal problems
assessment of vital signs is mandatory. • Neurological problems
The American Society of Anesthesiologists (ASA) has • Miscellaneous conditions, like pregnancy, nutritional
categorized risk for surgical patients as follows: deficiency, addiction, etc.
ASA 1: Healthy patients (require no modification of
surgical treatment plan). Physical Examination
ASA 2 and 3: Patients having mild to moderate systemic It includes inspection, palpation, percussion and
disease (require medical consultation and modification auscultation.
of surgical treatment plan). The general physical examination is followed by local
examination of the maxillofacial region.
ASA 4, 5 and 6: Patients having significant systemic
problems (preferably not treated in dental clinic). Laboratory Investigations
Patients with sub-acute bacterial endocarditis and
a. Hematological investigations like Hb, BT, CT, TLC,
prosthetic joints should be administered with prophyl-
DLC, platelet count (complete blood count), diabetic
actic antibiotics. Patients on anticoagulant therapy (such
screening (fasting blood sugar, glucose tolerance test,
as warfarin) are required to stop medication two days
etc.).
before treatment. Patients on aspirin therapy should
b. Urine investigations
stop medication 4–5 days before surgery. International
• Gross examination: Like color, odor, etc.
normalized ratio (INR) and prothrombin test should
• Chemical examination: For presence of glucose,
be carried out at least a day before surgery.
ketones, etc.
Anatomic Considerations • Microscopic examination: For presence of RBC,
A thorough clinical and radiographic examination epithelial cell, etc.
should be carried out to evaluate access to surgical site. c. Biochemical investigations: For uric acid, serum
The anatomical problems can be: cholesterol, blood urea, serum bilirubin, etc.
d. Radiological examination
• Restricted access
• Extraoral radiographs
• Root tips inclined lingually
• Intraoral radiographs
• Small oral opening • Special radiographic examinations
• Active facial muscles e. Histopathological investigations
• Shallow vestibule • Biopsy
• Thick buccal alveolar bone f. Microbiological investigation: For bacterial, viral and
• Proximity to mandibular canal, mental foramen, protozoal infections, etc.
maxillary sinus or nasal floor
Special Investigations
Informed Consent Special investigations includes ELISA, tuberculin test,
Any postoperative complication specific to a particular Widal test, VDRL test, etc.
situation/medical condition should be informed;
written consent may also be obtained from the patient. Presurgical Preparation
The tolerance of the surgical procedure, the incidence
PRESURGICAL EVALUATION of complications, and the quality and rate of healing
Presurgical evaluation includes the following. are all affected by the health of the patient. Therefore,
it becomes goal of the surgeon to maximize physical
Case History
32 Case history comprises data recording with regard to
chief complaint, history of present illness, family history
condition of the patient prior to surgery.
The most important decisions concerning surgical
procedures are made long before any anesthetic agent

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 Surgical Endodontics 555

is administered. The decision to perform surgery should • The arms are rinsed of excess soap after scrubbing.
be the culmination of several diagnostic steps. The rinse should be carried out with the elevated
The important steps prior to surgery are as arms so that the water will drain from the finger tips,
follows. progressing down the hands, arms and finally elbow.
The hands and arms are not rubbed during rinse and
A. Premedication only superficial soap is removed in the process; the
Premedication can be defined as ‘the preliminary drugs residual soap provides about three hours of anti-
with specific pharmacological actions, given prior to surgery bacterial action for the surgeon’s hands.
to achieve the requisite goals’. • The drying with sterile towel begins at the fingertips
of one hand and progress down the hand and arm
The requisite goals are: in a similar manner.
• Relief of apprehension/anxiety
• Sedation b. Gloving
• Analgesia There are two types of gloves. The most common type
• Amnesia of preoperative events is clean latex. For those who are allergic to latex, milled
rubber gloves are available. These are thinner than the
• Antisialagogue effect
latex gloves and may provide better tactile sensation,
• Reduction of stomach acidity and volume but are more fragile.
• Prevention of nausea and vomiting
C. Preparation of the Surgical Site
The premedication agents are:
The operative site may not be sterilized thoroughly;
• Sedative and hypnotic agents
however, the gross cleaning action can significantly
– Benzodiazepines (diazepam, midazolam, etc.) reduce the incidence of postoperative infection.
– Barbiturates (phenobarbitone) The scrub should begin in the center of the area of
• Analgesic agents: Opioids (morphine, pethidine) preparation and then moved concentrically. This will
• Anticholinergic agents (atropine, glycopyrrolate, etc.) minimize contamination of already cleaned region
from unscrubbed one. The area may be scrubbed a
B. Preparation of the Surgeon and the Patient second time with a new sterile gauze in the same
a. Hand Scrub manner as the first. The area near eyes and ears should
be taken care of.
Clean hands beneath gloves are necessary. The purpose
of hand scrub is to remove the superficial contaminants Draping the Patient
and loose epithelium and to reduce bacterial count on
The purpose of draping the patient is to isolate the
the skin. 20% chlorhexidine and 7.5% povidone iodine
surgical areas from other parts of the body. A double
are the routinely used agents for hand scrubbing.
layered drape is necessary for effective isolation.
It is recommended that the scrubbing procedure A sterile head drape is used around patient’s head
(using soap) should take approximately 10 minutes. and is secured with towel clips.
The steps followed are: The anesthetist and the equipment are isolated from
• Before beginning of hand scrub, the nails should be the operating team by a drape covered screen.
checked for cleanliness.
• The scrub begins at the tip of one finger of one hand. LOCAL ANESTHESIA
The long axis of the finger is divided into four
Local anesthesia is defined as ‘the loss of sensation in a
surfaces and 30 scrub strokes are applied to each
circumscribed area of the body caused by inhibiting the
surface. After this, the inter webbing is given 30
excitation of nerve endings or blocking the conduction process
strokes and the next finger is begun. Then the ventral,
in peripheral nerves, without inducing loss of consciousness’.
dorsal and lateral surfaces of the hands are cleaned
along with forearms.
Common Terms used in Local Anesthesia
• Then scrubbing is progressed towards the elbow,
extending two inches above it. Analgesia: It is loss of pain sensation without loss of
consciousness.
• When one area is scrubbed, it should not be touched
again because of the possibility of contamination
from unscrubbed area.
Regional analgesia: It is loss of pain sensation over a
given region without loss of consciousness.
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Regional anesthesia: It is loss of all sensations, i.e. pain • Duration of anesthesia as required for specific
as well as temperature, pressure and motor function procedures
without the loss of consciousness. • Presence and extent of infection
Topical analgesia: It renders the free nerve endings in • When anesthesia of a single tooth or a small area is
accessible structure (intact mucous membrane, abraded required, extraoral block is not used. Where
skin, etc.) incapable of stimulation by the application profound anesthesia is required, an intraosseous
of a suitable solution directly to the surface area. method or a nerve block should be preferred.
• When longer duration of anesthesia is required, a
Local infiltration: The small terminal nerve branches nerve block is the method of choice. The nerve block
in the area of surgery are flooded with local anesthetic may be preferred even if a small area is to be
solution rendering them insensible to pain or anesthetized. Also, if infection in the region
preventing them from becoming stimulated and precludes the use of local infiltration, nerve bock
creating an impulse. becomes a preferred choice even if a small area is to
be anesthetized.
Field block: It consists of depositing local anesthetic
solution in close proximity to a large terminal nerve Indications
branch so that a circumscribed area is walled off to
prevent central passage of afferent impulses. In endodontics, local anesthesia is used for:
• During radiography, especially in sensitive patient
Nerve block: It consists of depositing local anesthetic who are prone to gagging during placement of film
solution within close proximity to the main trunk and • For access cavity preparation
thus preventing afferent impulses traveling beyond that • For pulpotomy and pulpectomy
point. • Incision and drainage of abscess
• In surgical endodontic procedures like apicoectomy,
Ideal Requirements of Local Anesthetic hemisection, etc.
An ideal local anesthetic should possess the following • For diagnostic purposes; when the patient is not able
properties: to pinpoint the offending tooth.
• Action must be reversible. • During surgical procedures as an adjunct with a
• Remain stable in solution and undergo biotrans- vasoconstrictor for bloodless field.
formation readily within the body.
• Should be either sterile or capable of being sterilized Contraindications
without deterioration. The contraindications can be ‘absolute’ or ‘relative’.
• Must be non-irritating to the tissues and produce no
secondary reaction. Absolute
• Should have a low degree of systemic toxicity. • Allergy to anesthetic solution(s).
• Should not produce any allergic reactions. Relative
• Should have a rapid onset and be of sufficient • Local infections may render the drug ineffective.
duration. • Un-cooperative patients.
• Should have sufficient penetration to be effective for • Patient refuses regional anesthesia because of fear
topical use. or apprehension.
• Should have sufficient potency to provide proper • Surgical procedures, which need prolonged anesthesia.
anesthesia. • Anomalies make regional analgesia difficult or
Although the present local anesthetics do not fulfill impossible.
all these requirements, but still possess sufficient • Systemic conditions, like renal and liver diseases
properties for safe and effective use. affect the metabolism and excretion of the drug.

Selection of Method of Local Anesthesia Advantages

The selection of the method of local anesthesia depends • Patient remains awake, co-operative and well
upon the following factors: oriented.
• Age of the patient • Very low incidence of morbidity.
32 • Area to be anesthetized
• Profoundness of anesthesia required
• Minimal distortion of normal physiology.
• Techniques are simple.

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 Surgical Endodontics 557

• No additional trained person is necessary. 3. Based on site of Administration

• Failure rate is less. • Injectable anesthetics
• Patient need not omit the previous meal. – Low potency (Short duration): Procaine, 2-
Chloroprocaine
Mode of Action – Intermediate potency (Medium duration):
The anesthetic salts are formed by a reaction of a weak Lignocaine, Prilocaine
base and a strong acid. Water solubility is necessary – High potency (Long duration): Dibucaine,
for their diffusion through the interstitial fluids to the Tetracaine, Bupivacaine
nerve fiber. The salts exist both as uncharged molecules • Topical anesthetic
(free base) and the positively charged molecules (cation) – Water soluble: Cocaine, Lignocaine Hydro-
in equilibrium with each other in an anesthetic solution. chloride, Tetracaine
The relative proportion between the uncharged base – Water insoluble: Benzocaine, Lignocaine Base,
and the charged cation depends on the pH of the Butyl-amino Benzoate
solution and the pKa of the specific chemical cation
form. The uncharged form (Free base) is responsible 4. Based on duration of action
for optimal diffusion through the nerve sheath. After • Ultra short acting anesthetics (less than 30
penetration, re-equilibrium occurs between the free minutes)
base and the cation form. The charged cation binds to – Procaine without a vasoconstrictor
the receptor site and is ultimately responsible for – 2-chloroprocaine without a vasoconstrictor
suppression of nerve transmission. – 2.0% Lignocaine without a vasoconstrictor
The sensory functions are lost in the following order – 4.0% Prilocaine without a vasoconstrictor for
and the return of sensation is in the reverse order: infiltration
• Pain • Short acting anesthetics (45–75 minutes)
• Temperature – 2.0% Lignocaine with 1:1 lakh adrenaline
• Touch – 2.0% Mepivacaine with 1:2 lakh adrenaline
– 2.0% Procaine, 0.4% propoxycaine with a vaso-
• Proprioception
constrictor
• Skeletal muscle tone – 4.0% Prilocaine when used for nerve block
• Medium acting anesthetics (90–150 minutes)
Classification of Local Anesthetics
– 2.0% Lignocaine and 2% Mepivacaine with a
1. Based on Source vasoconstrictor for pulpal anesthesia
• Natural – 4.0% Prilocaine with 1:2 lakh adrenaline
– Cocaine • Long acting anesthetics (more than 150 minutes)
• Synthetic nitrogenous compounds – 0.5% Bupivacaine with 1:2 lakh adrenaline
– Ester Type – 0.5% or 1.5% Etidocaine with 1:2 lakh adrenaline
– Amide Type 5. Based on biological site and mode of action
• Synthetic non-nitrogenous compounds • Class A: Acting at receptor site, located on external
– Benzyl Alcohol surface of nerve membrane
• Miscellaneous drugs – Tetrodotoxin, Saxitoxin
– Clove Oil • Class B: Acting at receptor site, located on internal
– Phenol surface of nerve membrane
– Quaternary ammonium analogues of lidocaine,
2. Based on Chemical Group Scorpion venom
• Ester Group • Class C: Acting by a receptor-independent physico-
– Benzoic acid esters: Cocaine, Benzocaine chemical mechanism
– Para-amino benzoic acid esters: Procaine, 2- – Benzocaine
Chloroprocaine, Tetracaine, Propoxycaine • Class D: Acting by combination of receptor-
• Non-ester group (Amide/Anilide Type): Ligno- mediated and receptor-independent mechanisms
caine, Bupivacaine, Prilocaine, Dibucaine
• Quinolones: Centbucridine
– Lidocaine, Mepivacaine, Prilocaine (Most
clinically useful local anesthetic)
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Composition of an Injectable Local Anesthetic local anesthesia is injected gets anesthetized. The
Solution anatomic landmarks are not much important.
Each 1.0 ml of 2.0% Xylocaine with 1:2 lakh adrenaline It is indicated when only the mucous membrane and
consists of following: underlying connective tissues are to be anesthetized.
1. Lignocaine hydrochloride (21.3 mg) (local anesthetic Technique
agent): Lidocaine/Xylocaine/Octocaine is used as hydro- A long, 25 gauge needle is inserted beneath the mucous
chloride salt which is readily water soluble and can membrane into the connective tissue in the area to be
withstand boiling and autoclaving. anesthetized. The solution is injected slowly through-
• Pharmacology: Diffuses readily through interstitial out the area (Fig. 32.1).
tissues and into the lipid rich nerves, giving a rapid Probe or any other suitable instrument can be used
onset of action. It is two times more potent and toxic to evaluate onset of anesthesia.
as compared to procaine.
• Onset time: 2–3 minutes 2. Block of Terminal Branches
• Duration: 30–75 minutes Large terminal branches of any area are anesthetized.
• Dose: 4.4 mg/kg (not to exceed 300 mg when not The anatomical landmarks depend on the areas to be
accompanied by a vasoconstrictor) and 7 mg/kg (not anesthetized.
to exceed 500 mg when used with vasoconstrictor). It is indicated for one or two maxillary teeth. Blocking
2. Adrenaline/epinephrine (vasoconstrictor) 0.005 mg: It the larger terminal branches in mandible is difficult
is the most potent vasoconstrictor used in dentistry. because of its denseness. However, it may be used to
Concentrations from 1:50000 to 1:250000 are commonly block terminal branches of mandible in younger
used. Excessive doses may produce side effects individuals.
primarily in cardiovascular, respiratory and central Techniques
nervous system. Its addition in local anesthetic solution
a. Paraperiosteal technique: The success of this technique
provides the following effects:
depends on the diffusion of the solution through the
• Prolongs duration of action of local anesthesia by
periosteum and into the underlying bone to come in
decreasing their rate of removal from the local site
contact with the underlying nerves. The bone covering
into the circulation.
the deciduous maxillary teeth is thicker than the bone
• Enhances the intensity of nerve block.
covering the maxillary permanent teeth. When one or
• Reduces systemic toxicity of local anesthesia by two teeth are to be anesthetized, the 25 gauge needle is
decreasing their absorption.
inserted into the mucobuccal fold so that it makes
• Provide hemostasis by vasoconstriction. contact with the periosteum opposite and just above
3. Sodium metabisulphite (preservative) (0.5 mg) the apex of the tooth. 1.0–2.0 ml solution is deposited
• Prevents oxidation when exposed to air. slowly. Sometimes, intraosseous (the solution is injected
4. Sodium chloride (6.0 mg) into the bone by creating a hole) or interseptal (the
• Makes the solution isotonic.
5. Methylparaben (1.0 mg)
• Used as preservative; however, it is primarily
responsible for allergic reactions.
6. Distilled water (1.0 ml)
• Provides volume to solution (as diluent)
• Thymol (fungicide) was present earlier as bacterio-
static agent; nowadays, it is not used.

TECHNIQUES OF REGIONAL ANESTHESIA

A. Anesthesia for Maxillary Nerve
and its Subdivisions
1. Local Infiltration
32 Local infiltration anesthetizes terminal branches of the
free nerve endings at that site. The area into which the Fig. 32.1 Local infiltration (submucosal anesthesia)

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 Surgical Endodontics 559

Fig. 32.2 Intraosseous anesthesia

solution is injected into the thin porous interseptal bone

on either side of the tooth) techniques are also used
(Fig. 32.2). Fig. 32.3b Intraligamentary anesthesia
b. Intraligamentary technique: Special syringes have been
developed to permit the solution to be injected under as a primary injection, it is effective for 10–20 minutes;
high pressure (Fig. 32.3a). The injection may also be whereas, a supplemental injection with inferior alveolar
given with conventional syringes. A 30 gauge needle nerve block, the effect is more pronounced.
is introduced through the gingival sulcus and into the
Complications
periodontal ligament. The solution is injected with high
pressure, forcing rather than diffusing the solution • Postoperative discomfort: The postoperative dis-
through periodontal ligament (Fig. 32.3b). It is advised comfort is related to the damage from the insertion
that single rooted teeth be injected on the mesial/distal of needle and not from the pressure of solution
side or buccal/lingual side and the multirooted teeth deposition. Initial discomfort mostly resolves within
be injected over each root. a day.
It is documented that intraligamentary anesthesia • Avulsion: Tooth avulsion, as hypothesized earlier, has
produces immediate onset of anesthesia. When used not been documented adequately.
• Occlusal disturbances: Feeling of high in occlusion
resolves within 24 hours.
c. Intrapulpal: Once the pulp chamber has been exposed,
the needle may be introduced directly into the pulp
(Fig. 32.4). The needle is wedged firmly into the pulp
chamber or root canal and 0.1 to 0.2 ml solution is
injected into canal. The anesthesia is achieved due to
pressure and not by the amount of anesthetic solution
injected into the canal.

3. Infraorbital Block (Anterior and Middle Superior

Alveolar Nerves)
The infraorbital, anterior and middle superior alveolar,
inferior palpebral, lateral nasal and superior labial

Fig. 32.3a Syringe for intraligamentary anesthesia

nerves are anesthetized by this block. The incisors,
cuspids, bicuspids and mesiobuccal root of first molar
including the bony support and soft tissues, upper lip,
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 560 Essentials of Endodontics

Fig. 32.5 Infraorbital nerve block

entering the orbital cavity. Approximately 2.0 ml of

solution is injected in the area.

Fig. 32.4 Intrapulpal anesthesia 4. Posterior Superior Alveolar Block

The posterior superior alveolar nerve is anesthetized.
lower eyelid, portion of nose on the side of injection
The maxillary molars, except the mesiobuccal root
are the areas which get anesthetized.
of first molar, buccal alveolar process of the maxillary
The anatomical landmarks, viz. infraorbital ridge,
molars including the overlying tissues are the areas
infraorbital notch, anterior teeth and pupils of eyes are
which get anesthetized.
important for this block.
The anatomical landmarks viz. mucobuccal fold and
Technique its concavity, zygomatic process of the maxilla, infra-
The supraorbital and infraorbital notches are palpated. temporal surface of maxilla, anterior border and
An imaginary line is drawn passing through the pupils coronoid process of the ramus of the mandible and
of the eye, the infraorbital foramen, bicuspid teeth and tuberosity of the maxilla are important for this block.
the mental foramen. The palpating finger is moved This block is indicative for operative procedures of
about 0.5 cm below infraorbital notch located on the maxillary molars and supporting structures.
infraorbital rim where a shallow depression will be felt.
This corresponds to infraorbital foramen. An Technique
appropriate long 25 gauge needle is inserted into the For the right side block, the left forefinger is moved
mucobuccal fold from either of the two techniques over the mucobuccal fold in a posterior direction from
(directions) (Fig. 32.5). In the first technique the operator the bicuspid area until the zygomatic process of maxilla
inserts in a line parallel with the supraorbital notch, is reached. At this particular point the finger is rotated
the pupil of the eye, infraorbital notch, and the second so that the fingernail is adjacent to the mucosa and its
bicuspid tooth. The needle should be inserted 5.0 mm bulbous portion is still in contact with the posterior
buccal to the mucobuccal fold to pass over canine fossa. surface of the zygomatic process. The hand is lowered,
The thumb over the infraorbital foramen should be used keeping the bulbous portion of the finger still in contact
to guide the needle into the position where it contacts with the zygomatic process. An appropriate long 25
the bone at the entrance of the infraorbital foramen. gauge needle is held in pen grasp and inserted into the
The second technique of insertion bisects the crown tissues in a line parallel to the index finger and bisecting
of the central incisor from the mesioincisal angle to the the fingernail for a distance of approximately half to
disto-gingival angle of the same side. The needle is one-third inch. The solution is slowly injected. For left

32 inserted towards the infraorbital foramen. In either

approach, the needle should not penetrate more than
three-fourth of an inch. This prevents the needle from
side block, the patient and the left arm is passed around
the patients head so that the area may be palpated with
the left forefinger.

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 Surgical Endodontics 561

5. Nasopalatine Nerve Block internal oblique ridge, pterygomandibular ligament,

Nasopalatine nerve is anesthetized. This nerve block is buccal sucking pad, pterygomandibular space are
not commonly used in endodontics. important for this block.
It is indicated for palatal anesthesia and also to Technique
complete the anesthesia of nasal septum. The operator stands in front of the patient and with the
The anterior portion of hard palate and overlying left index finger or thumb palpates the mucobuccal fold.
structures up to bicuspid area are anesthetized. The finger is then moved posteriorly until contact is
The anatomical landmarks, viz. central incisors and made with the external oblique ridge on the anterior
incisive papilla are important for this block. border of ramus of mandible. When the finger or thumb
contacts the ramus of mandible, it is moved up and
6. Anterior Palatine Nerve Block (Greater Palatine down until the greatest depth of the anterior border of
Nerve Block) the ramus is identified. This is called the coronoid notch
Anterior palatine nerve is anesthetized. The posterior and is in direct line with the mandibular sulcus. The
portion of hard palate and overlying structures up to palpating finger is moved lingually across the
first bicuspid are anesthetized. retromolar triangle and onto the internal oblique ridge.
It is indicated for palatal anesthesia to be used in The finger is then moved to the buccal side, taking with
conjunction with the posterior superior alveolar nerve it the buccal sucking pad. An appropriate long, 25 gauge
block. needle is then inserted parallel to the occlusal plane of
The anatomical landmarks, viz. second and third the mandibular teeth from the opposite side (Fig. 32.6),
maxillary molars, palatal gingival margin of second and at a level bisecting the finger nail. The depth of insertion
third maxillary molars, midline of palate, a line is assessed by estimating when the needle tip has been
approximately 1.0 cm from the palatal-gingival margin advanced half the distance between the palpating index
towards the midline of the palate are important for this finger. Patient is asked to keep the mouth wide open.
block. The needle is inserted gently, making contact with the
internal surface of ramus. The needle is then withdrawn
Technique about 1.0 mm and 1.0–1.8 ml solution is injected. For
The greater palatine foramen is approached from the left side, the operator stands slightly to the back and
opposite side with an appropriate long, 25 gauge right side of the patient. The left arm is placed around
needle, which is kept as near to right angle as possible the patients head so that the landmarks can be palpated
with the curvature of the palatal bone. The needle is with the left finger. The needle is slightly withdrawn
inserted till the palatal bone is encountered and then and the lingual nerve is anesthetized.
0.25 to 0.5 ml of the solution is deposited very slowly.

B. Anesthesia for Mandibular

Division and Subdivisions
1. Inferior Alveolar Nerves Block (Direct Conventional
Inferior Alveolar Nerve Block): Open Mouth Approach
This is the most commonly used nerve block in
endodontics.
The inferior alveolar nerve and its subdivisions,
mental nerve, incisive nerve, and occasionally the
lingual nerve and buccinator nerve are anesthetized.
The body of mandible and inferior portion of ramus,
mandibular teeth, mucous membrane and underlying
tissues anterior to the first mandibular molar are
anesthetized.
It is indicated for procedures on the mandibular teeth
and supporting structures, anterior to the first molar.
The anatomical landmarks, viz. mucobuccal fold,
anterior border of the ramus of mandible, external
oblique ridge, coronoid notch, retromolar triangle, Fig. 32.6 Inferior alveolar nerve block
32

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 562 Essentials of Endodontics

2. Vazirani-Akinosi Inferior Alveolar Nerve Block: identified. Operator visually aligns the intraoral and
Close-Mouth Approach extraoral landmarks, and the needle is introduced
The inferior alveolar nerve and its subdivisions, mental through the mucosa just medial to the temporal tendon
and incisive nerves, lingual and buccinators nerves are and directed towards the target area on a line extending
anesthetized. The anesthetized area includes mandi- from the corner of the mouth to the intertragic notch.
bular hard and soft tissue to the midline including the The degree of divergence of the external ear to the head
floor of mouth and anterior two-thirds of the tongue. is used as a guide to the lateral flare of the ramus.
The anatomical landmarks are the occlusal plane of Needle insertion should be parallel to the flare of the
occluding teeth, mucogingival junction of the maxillary ear. Needle is advanced till the fovea region of the
molar teeth and anterior border of ramus. condyle is contacted. Depth of insertion should not
exceed 25–27 mm. If bone contact is not established,
Technique the needle should be withdrawn and redirected after
With the mouth closed, the needle is aligned parallel checking the landmarks again. After injection, the
to the occlusal plane and positioned at the level of the patient is asked to keep the mouth open for 20–30
muco-gingival junction of the maxillary molars. The seconds to allow adequate bathing of the nerve trunk
operator retracts the patient’s lip and the needle is that has been straightened by open mouth. The onset
penetrated about one and a half inches into the mucosa of anesthesia takes five to seven minutes.
just medial to the ramus. After negative aspiration, the
solution is slowly deposited. 4. Lingual Nerve Block
Lingual nerve is anesthetized by this block leading to
Advantages regional anesthesia of anterior two-thirds of the tongue
• Simple and easy to master technique. and the floor of the mouth, mucosa and mucoperiosteum
• Three major nerves are anesthetized by single needle on the lingual side of the mandible.
injection. It is indicated for procedure on the anterior two-
• Fear of injection into the throat does not exist. thirds of the tongue, floor of the oral cavity and mucous
• Useful in patients with limited mouth opening like membrane on the lingual side of the mandible.
trismus, space infection, etc.
Technique
Disadvantage Same as inferior alveolar nerve block.
• Relies on minimum bony landmarks.
5. Long Buccal Nerve Block
3. Inferior Alveolar Nerve Block (Gow-Gates Long buccal nerve is anesthetized. The areas anesthetized
Technique): True Mandibular Nerve Block are, buccal mucous membrane and mucoperiosteum of
Inferior alveolar nerve and its subdivisions, mental the mandibular molar.
nerve, incisive nerve, lingual nerve and buccinator, The block is indicated for anesthesia of the mandi-
mylohyoid, auriculotemporal nerves are anesthetized bular buccal mucosa and to supplement the inferior
by this technique. alveolar nerve block.
All mandibular hard and soft tissues up to the The anatomical landmarks for block are external
midline including the floor of the mouth and anterior oblique ridge and retromolar triangle.
two-thirds of the tongue, the skin over the zygoma, the
Technique
posterior portion of cheek, temporal region and a
portion of external ear will be anesthetized. The needle is inserted in the buccal mucosa just distal
to the third molar depositing 0.25–0.5 ml anesthetic
It is indicated for operative and surgical procedure
solution in this area. An alternate technique is to insert
on the mandibular teeth.
the needle directly into the retromolar triangle.
Technique Instrumentation is necessary for the demonstration
The patient is placed in supine position and the operator of objective symptoms, since none of the subjective
stands to the right and slightly in front of the patient. symptoms are present.
Patient keeps the mouth wide open and remains in that
position till injection is completed. An imaginary line 6. Mental Nerve Block

32 is drawn from the corner of the mouth to the intertragic

notch of the ear. The anterior border of the mandible is
palpated, and the tendon of the temporal muscle is
Mental nerve is anesthetized resulting in anesthesia of
lower lip and mucous membrane in the mucobuccal
fold anterior to the mental foramen.

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 Surgical Endodontics 563

It is indicated for the surgery of the lower lip or 2. Mild or severe

mucous membrane in the mucobuccal fold anterior to 3. Transient or permanent
the mental foramen.
The complications can also be classified as:
Technique
The apices of the bicuspid teeth should be estimated. 1. Due to Solution Used
The needle should be inserted into the mucobuccal fold i. Toxicity
after the cheek has been pulled to the buccal side. The ii. Idiosyncrasy
tissues are penetrated till the periosteum of the iii. Allergy
mandible is contacted slightly anterior to the apex of iv. Anaphylactic reactions
the second bicuspid. 0.5–1.0 ml solution is injected. v. Infections caused by infected solutions
Both subjective and objective symptoms are present. vi. Local irritation or tissue reaction caused by the
Subjective symptoms are tingling and numbness of solution
lower lip; while for objective symptoms, instrumenta-
tion is necessary to demonstrate absence of pain 2. Due to Insertion of Needle
sensation. i. Syncope
7. Incisive Nerve Block ii. Muscle trismus
iii. Pain or hyperalgesia
Incisive nerve and mental nerve are anesthetized.
Mandible and overlying labial structures anterior to the iv. Edema
mental foramen, premolars, canines and incisors and v. Infections
lower lip are anesthetized. vi. Broken needle
It is indicated for anesthesia of the anterior mandible vii. Prolonged anesthesia other than from the
to the mental foramen and lower lip, when for some anaesthetic solution
reason, the inferior alveolar nerve anesthesia is viii. Hematoma
contraindicated or unnecessary. ix. Sloughing
x. Bizarre neurological symptoms
Technique
It is same as that for mental nerve block, except that the Advances in Local Anesthesia
needle point should penetrate into the mental foramen. Various advances in local anesthesia are as follows.
Subjective symptoms are numbness and tingling of
lower lip; whereas, for objective symptoms, instrumen- a. Computerized Local Anesthetic Administration
tation is necessary to demonstrate absence of pain Device
sensation. A computerized local anesthetic delivery system has
been developed as a possible means of eliminating pain
8. Local Infiltration due to injection. It consists of a conventional local anes-
Free nerve endings in the infiltrated area are anesthe- thetic cartridge linked to a disposable Luer-lock needle.
tized. Mucous membrane and mucoperiosteum in the The system delivers anesthesia at a constant pressure
infiltrated area are anesthetized. and controlled volume, regardless of the resistance in
It is indicated for soft tissue surgery in limited area. the tissues.
Technique b. Electronic Dental Anesthesia
The needle is inserted beneath the mucous membrane Transcutaneous electrical nerve stimulation (TENS) has
into the underlying tissues. More than one needle been used for the management of acute and chronic pain.
insertion may be necessary. The solution is deposited In many instances, proper use of electronic nerve
slowly and in minimal volumes. stimulation results in lack of need for local anesthetic.
Instrumentation is necessary for the demonstration The patient controls the level of anesthesia needed, and
of absence of pain, since none of the subjective once the unit is turned off, there is no numbness to
symptoms are present. recover from as with local anesthesia.
Patients with pacemakers, neurophysiological
Complications of Anesthesia
The complications of anesthesia are usually classified as:
1. Primary or secondary
disorders (like epilepsy) and pregnant women should
not be offered electronic anesthesia because of its
harmful side effects.
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c. EMLA (Eutectic Mixture of Local Anesthesia) c. Increased Blood flow due to Vasodilation
EMLA contains both lidocaine (2.5%) and prilocaine In such cases, higher concentrations of vasoconstrictors
(2.5%). It significantly reduces pain experienced during may produce profound anesthesia, e.g. 1:100000 or
needle insertion. It does not provide profound pulpal 1:80000.
anesthesia for major endodontic procedures.
Lidocaine-prilocaine eutectic mixture is marketed as d. Effect of Inflammation on Nociceptors
a cream base (EMLA cream) or a cellulose disk (EMLA Inflammatory mediators like Bradykinins, Prosta-
patch). EMLA cream is used as a local anesthetic for glandins, etc. activate or sensitize nociceptors. They also
topical application. EMLA is used to prevent pain asso- have a profound structural effect on these neurons. The
ciated with needle insertion, intravenous cannulation, Tetrodotoxin (TTX) resistant sodium channels are
laser hair removal and superficial surgery on skin. formed, which are less sensitive to lidocaine. To
EMLA patch (DentiPatchTM) is an adhesive, which is overcome this problem, the volume of anesthetic
absorbed by the mucosa. It is used as mild topical solution is increased (within the recommended
anesthesia for superficial dental procedures. It should maximum dose). It is helpful in two ways; first, it will
be applied at least one hour or prior to local anesthetic expose a greater length of the nerve to be blocked and
injection. secondly, it will block the population of TTX resistant
class of sodium channels.
Failure of Anesthesia in Endodontic Procedures
The failure of local anesthesia in endodontic procedures e. Psychological Factors
may be because of various reasons. The main reasons Patients with the history of experiencing inadequate
are: local anesthesia for dental procedures and those with
high level of anxiety and apprehension may also
a. Anatomic Causes contribute to local anesthetic failure. For managing such
Accessory innervations to the mandibular teeth, patients, a clinician should develop a positive and
especially molars, is the main cause of failure of local confident relationship with the patient. Also, drugs like
anesthesia. Various sources are: nerve to mylohyoid alprazolam, midazolam, etc. can be administered.
muscle, lingual nerve, upper cervical nerves and
auriculotemporal nerve. PRINCIPLES OF SURGERY
To overcome this problem, a nerve block given at a The general principles involved in surgery are:
higher level (Gow-Gates or Vazirani-Akinosi nerve
a. Painless surgery: The assurance of painless surgery
block technique) would predictably block the nerve
is important to avoid psychological and physical stress
impulses. Still, if pain persists, then the anesthetic
to the patient, which may predispose to shock, delay
solution is deposited at the apices of the teeth (intra-
in recovery and make the surgery under local anesthesia
ligamentary or intraosseous route).
more difficult.
b. Effect of Inflammation on Local Tissue pH Usually, most of the dental procedures can be carried
out under local anesthesia; however, general anesthesia
As inflammation/infection produces acidosis, the low
should also be the part of treatment option.
pH will result in a greater proportion of the local
anesthetic being trapped in the changed acid form of b. Asepsis: Asepsis implies methods, which prevent
the molecule and, therefore, unable to cross cell contamination of wound by environment. Sterilization
membranes. This is known as ‘ion trapping’. rather than disinfection is mandatory whenever tissue
To overcome this problem, it is suggested that drugs is penetrated or there is contact with blood or serum.
like 3.0% mepivacaine should be used, which would
c. Minimal damage of vital tissues: The damage of vital
increase the concentration of the molecules in the base
tissues during surgery should be minimum. Certain
form. The molecules can easily cross the cell membrane
radical operations may require the sacrifice of vital
producing profound anesthesia even at low pH.
structures; however, damage or loss of function should
A few authors disagree with this hypothesis. Firstly,
not be because of carelessness.
acidosis may be of minor magnitude, as extravasations
of RBC’s or protein products increases the buffering d. Adequate access: The surgical incisions in the skin

32 capacity of inflamed tissue. Secondly, change in pH is

a localized event and should be concern for infiltration
and not nerve block.
should be made along the ‘Resting skin tension lines
(RSTL)’ or natural skin creases ensuring the scar to be
more esthetic and less conspicuous.

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 Surgical Endodontics 565

Some commonly used skin incisions in the maxillo- 10. When repositioned, it should rest on a healthy bone
facial region are: and not on a defect or hematoma.
• Submandibular incision 11. Whenever incision is likely to involve free gingival
• Retromandibular incision margin, adequate care is taken not to disturb
• Preauricular incision epithelial attachment, otherwise during wound
• Brows incision healing there is distinct shift in epithelial re-
• Infraorbital incision attachment exposing the cementum.
• Coronal incision. 12. When the flap is raised, care should be taken to
avoid perforation of flap. Such perforations may
Principles of Surgical Incisions in Soft Tissues result in flap necrosis.
The principles followed for surgical incisions in soft 13. Flap is designed in such a way that there is no
tissues are: tension during retraction, surgery and suturing.
1. Incision must be made with a sharp blade. BP blade 14. The flap should be handled gently. Gentle handling
(15) is used in routine; however, during incision and is preferred during retraction with appropriate
drainage of an abscess, BP blade (11) is used. A sharp retractors. Failure to do so will result in tissue lacera-
blade cleanly incises the tissues without damage. tion, postoperative edema and tissue damage.
Such incisions heal without wound dehiscence. 15. Meticulous hemostasis during surgery is important.
2. Whenever an incision is made, blade should be held Excessive bleeding disturbs the fluid balance. It also
perpendicular to the epithelial surface and not results in poor visibility of the surgical field.
obliquely. Bleeding under the flap may result in subperiosteal
3. The incision must be firm and stroke must be conti- hematoma, which interferes with healing of the
nuous and deep to the bone. Supraperiosteal incisions flap.
and multiple strokes result in tissue damage. The Classification of Flaps
blood vessels are situated supraperiosteally;
incising over the periosteum while reflecting flap I. Based on bone exposure after reflection
protects supraperiosteal blood vessels. Short and • Full thickness flap (mucoperiosteal flap)
interrupted incisions must be avoided. To reduce • Partial thickness flap (split thickness flap)
bleeding, injection of vasoconstrictor solution into • Combination flap (full split type flap)
the area can be given prior to making incision. II. Based on presence/absence of vertical incisions
4. Incisions must be carefully planned in such a • Envelope flap (without vertical releasing incisions)
manner that vital structures are not damaged, e.g. • Relaxed flap (with vertical releasing incisions)
incision parallel to the long-axis of vessels will not III. Depending upon the shape of flap
damage the vessels. When operating in vascular • Two-sided/triangular flap
areas, the incision may be modified to reduce • Three-sided/trapezoidal flap
bleeding (electrosurgery may be used instead of • Semilunar flap
scalpel). IV. Based on the underlying specific blood vessel
5. The incisions should never be made over the • Pedicle flap
operative site but rather in adjacent undisturbed • Non-pedicle flap.
areas so that flap will be supported by normal
tissues and potential for revascularization is The routinely used flaps are:
preserved. Full Thickness Flap
6. Incisions should never be made in an area of The soft tissue including the periosteum is reflected to
thinned mucosa like that found over exostosis or expose the underlying bone (Fig. 32.7a and b). A full
other bony prominence because blood supply is thickness flap is performed by blunt dissection of the
reduced, suturing is difficult and rate of wound oral mucosa away from the teeth and alveolar bone.
dehiscence is high. This is carried out with periosteal elevators or any other
7. Flap must be designed to provide adequate access blunt instrument.
to the surgical area.
8. Flap must have broad base and good vascular Indication

32
supply. • Where access and visibility of the alveolar bone is
9. Length and breadth is an important factor. It is pre- required
ferable that length of flap does not exceed the base. • When primary wound healing is essential.

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 566 Essentials of Endodontics

a b
Fig. 32.7a and b Full thickness flap

Advantages
• Easy to perform than the split thickness flaps
• Improved visibility of the alveolar bone
• Generally associated with less bleeding and less post-
operative pain. Fig. 32.9 Combination flap

Partial Thickness Flap Envelope Flap

It includes only the epithelium and a layer of under- No vertical incision is given and the flap begins and
lying connective tissue (Fig. 32.8a and b). Partial ends within the gingival sulcus of the contiguous teeth
(Fig. 32.10).
thickness flaps are accomplished by using a scalpel,
which sharply dissect through the lamina propria of Advantages
gingiva and alveolar mucosa. • Because envelope flaps have no vertical incisions,
they are quicker to heal
Combination Flap • Less postoperative pain and bleeding.
The combination of both complete thickness and partial
thickness flap may be required to be used in certain Disadvantages
procedures (Fig. 32.9). • Limit the access to the bony tissues
• Cannot be moved/repositioned to other locations.

Relaxed Flaps
These flaps have vertical releasing incisions and offer
tremendous flexibility in terms of access and tissue control.
Advantages
• Better accessibility
• Can be repositioned to other locations.

32 b

Fig. 32.8a and b Partial thickness flap Fig. 32.10 Envelope flap

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 Surgical Endodontics 567

Disadvantages
• Vertical incisions delay healing as blood supply is
compromised.
• Greater postoperative pain and bleeding.

Two-sided/Triangular Flap
Two-sided triangular flap is designed by making a
releasing incision on the side of envelope flap that
should be preferably divergent towards the vestibular
sulcus forming an obtuse angle at the free gingival
margin (Fig. 32.11a and b).

Three-sided/Trapezoidal Flap
Fig. 32.12a Trapezoidal flap (diagrammatic)
Three-sided trapezoidal flap is a modification of two-
sided triangular flap with addition of a second vertical
incision towards vestibule to make better access
(Fig. 32.12a and b). Care should be taken to keep the
base of flap as broad as possible to ensure good blood
supply (base to length ratio should be 2 : 1).

Fig. 32.12b Trapezoidal (three-sided flap)

Fig. 32.11a Triangular flap (diagrammatic)
Semilunar Flap
The semilunar flap is designed when periapical area is
to be exposed. The height of incision is kept 5.0 mm
away from the free gingival margin (Fig. 32.13a and b).
This flap is preferred over the envelope flaps as there
is no gingival retraction. The main disadvantage is that
it leaves an unesthetic scar.
In edentulous case, horizontal incisions are placed
on the alveolar crest and vertical incisions remain at
the same place as in dentulous mouth.

Pedicle Flap
The flap based on specific blood vessel is known as
pedicle flap, e.g. in palate, flap based on greater palatine

Fig. 32.11b Triangular (two-sided flap)

vessels. If the flap is designed along the long-axis of
the blood vessel, the base of the flap will be located
around the maxillary third molar.
32

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 568 Essentials of Endodontics

The following features are important:

• When flap is reflected, care should be taken not to
damage important anatomical structures like neuro-
vascular bundles present around infraorbital and
mental foramen
• Take care of muscular attachments during flap
reflection
• Elevation of lingual mucoperiosteum near third
molar carries risk of injury to lingual nerve
• Elevation of the mucoperiosteal flap in the palate
needs careful consideration. Mucosa is tightly bound
to midpalatine suture. The incision placed in the
palate across the greater palatine vessels may results
Fig. 32.13a Semilunar incision (diagrammatic)
in brisk bleeding.

Bone Removal
Bone can be removed by chisel osteotome, surgical burs
and bone rongeurs/files, etc.
Chisel and osteotome: Chisel is a mono-bevelled
instrument while osteotome is bi-bevelled. Chisel along
with mallet is convenient and conventional method to
remove a portion of the bone. Osteotome is mainly used
for splitting of tooth or and bone.
Surgical bur: Surgical bur is used to cut bone or to divide
a tooth. Bone cutting must be carried out at slow speed
with copious irrigation to avoid thermal necrosis of bone.
Bone rongeurs or bone nibblers file: Bone rongeurs are
useful in clipping sharp and irregular margins of bone.
The rough surfaces of bone can be smoothened with
Fig. 32.13b Semilunar incision bone file.

Non-pedicle Flap Arrest of Hemorrhage (Hemostasis)

The flap not based on a specific blood vessel is termed The hemorrhage, if any, must be arrested before
non-pedicle flap. suturing the flap, otherwise accumulation of blood in
the dead space becomes a nidus for growth of bacteria.
Dissection and Reflection of Mucoperiosteal Flap Various methods used for hemostasis are:
• Digital pressure
Adequate retraction is essential for surgical access. The
retractor must rest on sound bone with light but firm • Hemostat or artery forceps
pressure. The mucoperiosteal flap may be reflected with • Ligature
a periosteal elevator. The elevator is first inserted into • Packing with gauge and hemostatic agents
the incision and starting in the buccal sulcus where • Electrocoagulation.
periosteum is loosely attached, the first few millimeters
at the edge of flap are gently freed along the periphery. Débridement and Drainage
Thereafter, it is reflected evenly along its periphery by The debris and pathological tissues must be cleaned
a clear movement with the end pressed and firmly kept from the wound before closure. The bone cavity and
against bone. The reflective forces should be applied flaps are trimmed off of all necrotic tissues or tags.
to the bone and periosteum with minimum force on Wound must be thoroughly irrigated with saline.

32 the gingiva. Lifting movements are avoided as they tend

to tear tissues. Bleeding tissue tags should not be
removed during surgery as they help in healing.
Dead space can be eliminated by adopting following
features: Suturing tissue planes together to minimize
the postoperative void, placing a pressure dressing over

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 Surgical Endodontics 569

repaired wound, packing void until the bleeding has The commonly used sutures are:
stopped and using drains, either alone or in addition
to pressure dressing. Gut/Catgut
Gut/catgut is the most popular absorbable suture
Wound Closure material. Plain catgut retains its tensile strength for
Wound closure by suturing help obliterate dead spaces approximately 10 days, while chromic catgut for 20
where accumulation of blood or other tissue fluids days. These are available in different sizes. Catgut is
could prevent direct apposition of tissues and provide absorbed by proteolytic digestive enzymes released
an environment favorable for bacterial growth. Sutures from inflammatory cells collected around the catgut (in
also distribute the tension of wound closure over a the presence of infection catgut is rapidly absorbed).
larger volume of tissues. Catgut is sterilized during preparation and kept in
isopropyl alcohol. It should not be boiled or autoclaved
SUTURE MATERIALS as heat destroys the tensile strength. It should be wiped
A suture is any thread or strand, which brings into with saline prior to use.
apposition of surfaces or tissues, while a ligature is any
Polyglactin 910 (Vicryl)
thread or strands which obliterates the lumen of
ductular structures. The suture material should be non- It is a synthetic absorbable suture material. It is braided
reactive, easy in handling and retain tensile strength to improve handling and is coated to reduce bacterial
till wound is completely healed. adherence and tissue drag. It is absorbed initially by
hydrolysis and then phagocytosed by polymorpho-
Classification of Suture Materials nuclear cells and other macrophages.
1. Absorbable It is available in different sizes.
a. Natural Advantages
i. Catgut (plain and chromic) • Minimum tissue reaction
ii. Fascia lata • No fraying
iii. Kangaroo/beef tendon • Excellent handling characteristics
b. Synthetic
• Distinct violet color is highly visible in the wound
i. Polyglactin 910 (vicryl)
• Unique molecular structure (retains its strength
• Polyglycolic acid
during the healing period and then get absorbed
• Polydioxanone. rapidly).
• Polyglecaprone 25 (monocryl)
ii. Irradiated Polyglactin 910 (vicryl rapid) Disadvantage
2. Nonabsorbable Roughness.
a. Natural
Irradiated Polyglactin 910 (Vicryl Rapid)
• Silk
• Cotton It is braided synthetic absorbable, white color suture
• Linen material, ideal for intraoral use.
b. Synthetic. It has a similar initial high tensile strength as that of
• Polyamide the normal vicryl suture. It gives wound support up to
• Monofilament 12 days. Its absorption is associated with minimal tissue
• Polyfilament (braided) reaction facilitating improved cosmetics and reduction
of postoperative pain.
• Polyester
• Polyfilament Silk
• Uncoated
It is natural, nonabsorbable, polyfilament suture
• Coated (with polybutylate)
material, obtained from the cocoon of silkworm.
• Polypropylene-monofilament (prolene)
• Polybutester-novafil Advantages
• Metals • Does not soak fluids and never becomes brittle.
• Stainless steel
• Platinum
• Silver.
• Ties down smoothly and securely and its natural
elasticity gives it an extensibility that signals when
optimum knot placement has been achieved.
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 570 Essentials of Endodontics

Disadvantage • When a wound has reached maximal strength,

• Infection rate is high as compared to synthetic sutures are no longer needed. Absorbable sutures
materials. are preferred in tissues that heal rapidly. Tissues that
heal slowly are closed with nonabsorbable sutures.
Cotton • Multifilament sutures should be avoided in contami-
It is a natural, nonabsorbable (twisted polyfilament) nated wounds as bacteria can linger within the suture.
suture, available in reels in an unsterile form. It can be • In case of cosmetic results, close and prolonged
sterilized by autoclaving. apposition of wound is achieved using inert mono-
Advantages filament suture (polyamide or prolene).
• Knot is secured • Multifilament braided materials, such as black silk,
• Easy handling or absorbable synthetic materials, such as polyglactin-
• Cheap and freely available. 910 are preferred for intraoral use.

Disadvantages SURGICAL NEEDLES

• Absorbs fluids by capillary action (more chances of
The surgical needles are sharp pointed instruments
infection)
made of stainless steel or carbon steel. These are used
• Shows more tissue reaction
for puncturing the tissue so as to guide the thread or
• Frays easily wire to suture. The needles are available in a wide range
• Low tensile strength. of types, shapes, lengths and thickness.
Linen
Classification of Surgical Needles
It is a natural, nonabsorbable, polyfilament suture of
• According to its eye
natural linen color.
– Eyeless needles (swaged)
Advantages – Needles with eye
• Knots slide down smoothly and tie securely • According to shape
• Smooth and nonirritating. – Straight needles
Nylon – Curved needles
• According to cutting edge
It is a synthetic, easily available nonabsorbable suture.
– Round body needles
Advantages – Conventional cutting needles
• Smooth and nonirritating. – Reverse cutting needles
• High tensile strength, which is retained for a long- • According to configuration tip
period. – Triangular tipped needles
• Cheaper. – Round tipped needles
Disadvantages – Blunt-point needles
• Knot is slippery (may need 5–7 knots) – Micro-point needles.
• Infection due to crevices in braided nylon. In endodontic surgery, the types of needles commonly used
are:
Stainless Steel
Stainless steel wires are available in different sizes. i. Eyeless needles: One strand of suture material is
attached to the swage of a needle during manufacturing.
Disadvantages
• Knots are not firm and may break Advantages
• May excite tissue reaction. • Causes minimal tissue trauma as only a single
swaged suture strand is drawn through the tissue.
Suture Selection • Each patient has the benefit of a new sharp needle.
The selection of a suture material should be based on Reusable needles are potentially dull, blurred or
sound knowledge of the healing characteristics of the tarnished.

32 tissues to be approximated, physical and biological • These needles do not unthread and can be easily
properties of the suture materials and condition of the recovered if accidentally dropped.
wound to be closed. • Allows faster, more efficient surgery.

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 Surgical Endodontics 571

ii. Needles with eye: These needles can be reused and • The knot should not be placed over the incision line.
are cheaper. The suture thread is changed with every • Sutures should be placed approximately 3.0–4.0 mm
surgery. apart.
• If ‘dog ear’ occurs at the end of incisions, it should
CLOSURE OF SURGICAL SITE be eliminated.
(TECHNIQUES OF SUTURING) • Apply firm pressure, at least for three to five minutes
The underside of reflected tissue, periradicular bone after suturing.
and the cavity should be inspected for any type of
debris. The surgical site is repeatedly washed with Knot Tying
normal saline. Gentle pressure is applied to reposition The operator may use either the instrument tie or one
tissues to remove excess blood and to begin intimate or two hand tie. The instrument tie is more convenient
attachment process. Reposition the flap and compress in closed areas such as mouth, but can be used in open
tissues against bone with moist sterilized gauze before areas as well.
suturing.
Surgeon’s knot is formed by two throws of suture
Principles of Suturing around the needle holder for first tie and one throw in
opposite direction for second tie (Fig. 32.14).
• The needle holder should grasp the needle at
approximately one-half to three-fourth of the Square knot: The basic knot is the square knot and
distance from the point. requires at least three ties for surface knots. It is formed
• The needle should enter the tissue perpendicular to by wrapping ties around the needle holder once in
the surface. If the needle pierces the tissue obliquely, opposite directions between ties (Fig. 32.15).
a tear may develop.
• The needle should be passed through the tissue
following the curve of the needle.
• The suture should be placed at an equal distance
from the incision on both the sides and at an equal
depth. This principle can be modified in case where
the tissue edges are at different levels; then passing
of the suture closer to the edge of the lower and
farther from the edge of the higher side will tend to
approximate the levels. Another method involves
passing of the suture at an equal distance from the
wound margins on both sides, but deeper into the
tissues on the lower side and more superficially on
the higher side.
• The needle should pass from the free tissue to the
Fig. 32.14 Surgeon’s knot
fixed side.
• If one tissue side is thinner than the other, the needle
should pass from the thinner tissue to the thicker
one.
• If one tissue plane is deeper than the other, then the
needle should pass from the deeper to the superficial
side.
• The distance that the needle is passed into the tissue
should be greater than the distance from the tissue
edge.
• The tissues should not be closed under tension, since
they will tear or necrose around the suture. If tension
is present, the tissues should be undermined to
relieve it.
• The suture should be tied so that the tissue is merely
approximated and the edges are everted. Fig. 32.15 Square knot
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 572 Essentials of Endodontics

Fig. 32.18 Continuous suture

Fig. 32.19 Locking continuous suture

Fig. 32.16 Granny’s knot
A simple interrupted suture is placed and needle is
Granny’s knot: This knot involves 1st tie in one then inserted in continuous fashion (Fig. 32.18). The
direction followed by a 2nd tie in the same direction as suture passes perpendicular to incision line underneath
the first. A 3rd tie is then squared in opposite direction tissue and diagonally on surface and is ended by tying
on the second to hold the knot permanently (Fig. 32.16). to last untightened loop of suture.

Methods of Suturing Continuous Locking Suture

The commonly used methods of suturing are: The suture is passed perpendicular to incision line
• Interrupted suture and degree of locking is provided by withdrawing
• Continuous suture suture through its own loop. The suture technique is
• Continuous locking suture begun and ended identical to continuous technique
• Mattress suture (Fig. 32.19).
• Figure of ‘8’ suture. Advantages
• The suture will align itself perpendicularly to the
Interrupted Suture
incision.
The interrupted suture is the most commonly used • The locking feature promotes continuous tightening
(Fig. 32.17). It can be used in the area of tension. of the suture as wound closure progresses. Care
Advantages should be exercised not to tighten the individual lock
• Successive suture can be placed excessively, since this can produce tissue necrosis.
• Each suture is independent of the next (loosening of
one suture will not cause loosening of the others; Mattress Suture
and/or few sutures during reinfection can easily be Mattress sutures are of two types:
removed). i. Vertical: The needle is passed close to incision line
on both sides. When needle is brought back from
Continuous Suture second flap to first flap, the depth of penetration is
The continuous suture provides a rapid technique for more superficial (Fig. 32.20a).
closure and even distribution of tension over the entire The vertical mattress suture is used to provide more
suture line. It provides water tight closure, which is tissue eversion and is used in areas where wound
especially important in intraoral bone grafting. It contraction could cause dehiscence and broad scar
should not be used in areas of existing tension. formation. The vertical mattress suture offers the
advantage of running parallel to the blood supply
of the edge of the flap and therefore not interfering
with healing.

32
ii. Horizontal: The suture passes perpendicular to
incision line underneath tissue and parallel to it on
Fig. 32.17 Simple interrupted suture the surface; again perpendicular to incision line

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 Surgical Endodontics 573

Suture Removal
Suture should be grasped with an instrument and
elevated above the epithelial surface during removal.
A scissors should be used to transect side of the loop as
close to the epithelial surface as possible. In this way a
minimal portion of the suture laden with debris and
Fig. 32.20a Vertical mattress suturing bacteria (open to environment) will be dragged through
the tissue.

Tissue Reaction to Sutures

The initial body response to sutures is almost identical
in the first 4 to 7 days, regardless of the suture material.
After one week the response is related to the type of
suture material.
If the suture material leads through mucosal or skin
surfaces, epithelial cells will begin tracking down the
Fig. 32.20b Horizontal mattress suturing
suture pathway. The longer the suture remains, the
deeper is the epithelial invasion of the underlying
underneath tissue to be knotted on that side tissue. When such sutures are removed, an epithelial
(Fig. 32.20b). tract remains. These cells may eventually disappear or
The interrupted horizontal mattress suture produces remain to form keratin and epithelial inclusion cysts.
broad contact of the wound margins and is useful A delay in sutures removal or excessive tension on the
where such a condition is needed. The disadvantage skin may also cause the site of the sutures to be visible
is the blood supply to the edges of the incision is and the typical ‘railroad track’ scar results.
constricted. The development of surgical infections is greatly
The continuous horizontal mattress suture is often used enhanced by the presence of a suture in a contaminated
after intraoral bone grafting, as the eversion and wound. The use of monofilament sutures rather than
continuity provide watertight closure. braided sutures reduces the potential for infection as
the multifilament sutures provide a heaven for bacteria,
Figure of ‘8’ Suture which can penetrate the interstices of the suture that
The figure of ‘8’ suture is used over extraction sites are too small to allow granulocytes and macrophages.
where it provides protection to the socket and adapta- As a general rule, sutures should not be used in the
tion of the gingival papillae round the adjacent teeth presence of infections and should be removed if an
(Fig. 32.21). infection becomes evident.
All sutures passing through the mucous membrane
The only disadvantage is that the suture is difficult
or skin provide a ‘wick’ down through which bacteria
to remove after wound closure.
can gain access to the underlying tissues and may cause
inflammation, subsequently granuloma or a stitch
abscess. Because of this and the downward growth of
the epithelial tissue, the sutures should be removed as
early as possible consistent with adequate healing.
Generally, sutures should be removed after 3 to 5 days
on the skin of the head and neck, and 5 to 7 days intra-
orally. The sutures in case of cancer should be removed
after two weeks.

SURGICAL ARMAMENTARIUM
The surgical armamentarium (Fig. 32.22) are:
For presurgical assessment

Fig. 32.21 Figure of ‘8’ suture

• Mirror and curved explorer
• Straight and curved periodontal probes.
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 574 Essentials of Endodontics

gain visual access to the surgical site. Bone removal is

carried out with round and fissure burs under copious
irrigation with normal saline. With the advent of
ultrasonic tips and microsurgical gadgets, the diameter
of an osteotomy is within 5.0 mm (exact position of root
tip is identified prior to making small sized osteotomy).
A periapical radiograph matches over the ‘estimated’
root tip. The area can be identified prior to use of
surgical burs. A small sized osteotomy lead to reduced
postoperative discomfort and faster healing.
Sometimes, a window is present in the bone due to
growth of periapical granulation tissue. The window
can be used as a starting point to cut bone round the
apex. An appropriate size surgical curette is used to
remove granulation tissue to improve visualization. The
Fig. 32.22 Armamentarium for endodontic surgery bony cavity can be modified for appropriate retrograde
fillings.
For soft tissue incision, elevation and reflection
• Scalpels Periradicular Curettage
• Disposable blades (sizes 11, 12, 15) Periradicular curettage is performed along with
• Mucoperiosteal elevator preparing bony cavity for better visualization of the root
• Mucoperiosteal retractor end. Sometimes, it is not possible to completely remove
• Tissue forceps the granulation tissue without resecting root. Straight
• Irrigating syringes and needles. and angled bone curettes are usually used to excavate
For periradicular curettage the diseased tissue. Injecting 0.5 ml of anesthetic
• Spoon curette solution in lesion decreases patient discomfort and also
• Periodontal curette improves hemostasis. Curettes are used in a scrapping
• Fine, curved mosquito forceps motion to detach soft tissue from bone. Loosened tissue
• Small, curved surgical scissors. is removed with the help of a tissue forceps. Caution
must be taken to prevent damage to the vital structures
For bone removal and root-end resection when working in proximity to maxillary sinus, mental
• Surgical burs foramen or mandibular canal. The bony cavity is cleaned
• Bone curettes. with sterilized gauge and checked for any residual bony
For root-end preparation and restoration spicules/diseased tissue. The cavity is then thoroughly
• Miniature contra-angle hand piece/ultrasonic hand washed with normal saline.
piece
• Burs and ultrasonic tips Apicoectomy (Root-end Resection)
• Hemostatic agent The removal of apical portion of the root may or may
• Restorative carriers and condensers not be necessary in all occasions. Usually, it is employed
• Small ball burnisher where retrograde filling is required or apical aberrations
• Small, fine explorer. warrant such resection. The other reasons for resection
of apical root are:
For suturing and soft tissue closure
• Surgical scissors • Removal of iatrogenic mishaps, such as ledges, block,
• Hemostat or fine needle holders etc.
• Sutures (size 3-0 to 5-0) • Reduction of fenestrated apical root
• Sterile gauze for soft tissue compression. • Evaluation of vertical fractures
• Achieving root canal access from apical end
SURGICAL PROCEDURES • Facilitate removal of granulation tissues.
Osseous Entry (Osteotomy)
32 The apical end of the root is identified. The bone
surrounding the root tip may need to be removed to
It has been established that at least 3.0 mm of root
end must be removed to remove apical ramifications
and to enhance visualisation of the periapical area.

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 Surgical Endodontics 575

The labial surface is beveled for better access and

visibility. Earlier 30–45° bevel was recommended. Once
the root has been exposed, the bur is placed at a desired
angle and the root is shaved away. A couple of authors
prefer cutting of root end without beveling. They are
of the view that beveling exposes more surface area,
which might lead to marginal leakage. It is established a b
that 10° bevel is beneficial for manipulation at the root
tip without leading to marginal leakage (Fig. 32.23).
Extent of removal of root-end is dictated by following
factors.
• Access and visibility to the surgical site
• Position of apical end of root within alveolar bone
• Presence of significant accessory canals
• Location of procedural error, if present
• Anatomical considerations, e.g. proximity of adjacent c d
roots, level of remaining crestal bone, etc.
Stepwise procedure of apicoectomy of left maxillary
central incisor tooth is depicted in Fig. 32.24. Apicoec-
tomy of first mandibular molar is shown in Fig. 32.25.

Root-end Preparation
The root-end preparation is carried out to seal the apical e f
opening of the root canal system. The preparation is
made parallel to the anatomic outline of root. The
depths of root end cavity depend upon the angle of
beveling. 1.0–1.5 mm depth is sufficient if no bevel is
given. Depth is more as the angle is increased (2.5 mm
deep for 45° bevel). Root-end cavity can be prepared
either with a bur used in a miniature handpiece or g h
ultrasonics. Ultrasonic tips are used in light, sweeping
motion (forward-backward). Interrupted strokes are Fig. 32.24 Apicoectomy procedure (left maxillary central
incisor): (a) Preoperative; (b) Incising the flap; (c) Flap raised;
more effective than the continuous ones. The prepared (d) Creating bony cavity; (e) Exposing root tip; (f) Root-
cavity is evaluated using micromirrors (Fig. 32.26). The end preparation; (g) Root-end filling; (h) Suture placed
ultrasonic tips allow good access to the root end and
provide the requisite shape (Figs 32.27 and 32.28). The
Root-end Filling Materials
cavity should be free of debris including gutta-percha.
The gutta-percha on the walls should be removed or The root-end cavity is isolated. The hemostatic agent
packed down in the canal. can be placed in the bony crypt. Manufacturer
instructions should be followed while choosing the
material for retrofilling and placing the same at the
retrocavity prepared. The bony cavity should be
cleaned thoroughly after the filling. The root-end filling
material should have the following features:
• Potential to seal the root canal hermetically
• Biocompatible with no inflammatory reaction
• Radiopaque
• Nontoxic
• Should not promote or preferably inhibit the growth
of pathogenic microorganisms

Fig. 32.23 (a) 0° bevel; (b) 45° bevel; (c) 10° bevel
• Moisture friendly
• Dimensionally stable
32

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 576 Essentials of Endodontics

a b c

d e

Fig. 32.25 Apicoectomy of first mandibular molar: (a) Fractured instrument lying in the periapical area (arrow);
(b) Apicoectomy of mesial root of first mandibular molar; (c) Root canal files in mesial canal; (d) Postoperative radiograph;
(e) Suture placed

Fig. 32.26 Micro mirror

Fig. 32.28 Root-end preparation with ultrasonic tip

• Should not corrode or be electrochemically active

• Should not stain the tooth or tissues.
The details of commonly used retrofilling materials
are described in Chapter 20.

Guided Tissue Regeneration (GTR)

32
a b

Fig. 32.27 Root-end cutting (a) Using round bur; (b) Using The term regeneration implies reproduction or
ultrasonic tip reconstruction of a lost or injured tissue. Guided tissue

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 Surgical Endodontics 577

regeneration refers to regeneration of periodontal A classification is proposed (VonArx and Cochran-

attachment (bone, periodontal ligament and cementum); 2001) for periradicular lesions suitable for GTR
whereas, guided bone regeneration refers to ridge techniques (Table 32.1).
augmentation and growth of bony tissue only. It has been shown that defects eroding both labial
Limited studies have been published using GTR and palatal cortical plate normally do not heal
techniques in endodontic surgeries. The most common completely; may fill with scar tissue (class Ib lesions).
lesion treated with GTR techniques are the endodontic– The use of membrane GTR technique has shown
periodontic lesions, wherein considerable bone loss is significant improvement in healing process. Class II
evident. It has been established that GTR improves lesions (endodontic–periodontal lesion) is always
healing of transosseous defects as compared to challenging. The loss of buccal bone compromises with
endodontic surgery without using GTR. the healing process. The operator must plan the
Guided tissue regenerative technique can utilize placement of membrane and bone grafts with and
bone grafts only or bone grafts with barrier membrane. without morphogenic scaffolds after assessing the bone
The placement of barrier membrane (polytetrafluoro- loss configuration around each root. Lateral/furcation
ethylene, polyglactin, collagen, calcium sulfate, lesions (class III) have also been surgically treated using
polylactic acid, etc.) prevents gingival epithelium and GTR approach. GTR therapy along with membrane
connective tissue from contacting the intended site of placement is particularly indicated for treatment of
bone reformation and interfering with osteogenesis furcation perforation lesions that communicate with the
(bone formation) (Fig. 32.29a and b). marginal periodontium.
It has been established that combination of graft and
Advantages of using barrier membrane
membrane is significantly better than barrier alone or
• Membrane provides additional wound coverage and
control group of patients treated conventionally.
stability/protection of blood clot.
However, a few authors have questioned the efficacy
• Facilitates in-growth of cells and blood vessels from
of GTR modality and opined that membrane might
the base of the lesion.
even prevent regeneration. It has also been questioned
• Maintain blood-clot area free of bacterial invasion.
in case of root-end surgeries. The healing in root-end
• Prevent other tissues (connective tissue) entering the surgery without using any GTR modality is quite
intended site of bone formation. predictable.
It can be personal preference of the operator to use
or not to use GTR techniques; however, using GTR
along with bone grafting is always beneficial for long-
term treatment outcome.
Although a substantial number of studies have
preferred using GTR techniques; it should also be noted

Periradicular lesions and guided tissue re-

Table 32.1
generation
Class I Periapical bone defect without marginal lesion
a Ia Lingual/palatal cortex not eroded
Ib Lingual/palatal cortex eroded (with a buccal
surgical approach, this will result in a transosseous
or through-and-through bone defect)
Class II Periapical lesion (with or without lingual erosion) and
concomitant marginal lesion)
IIa No communication between the separate lesions
IIb The two lesions are fused: endodontic–periodontal
lesion
Class III Lateral or furcation lesion (with or without marginal
lesion)
IIIa No communication to alveolar crest/marginal

32
b periodontium
IIIb Communication to alveolar crest/marginal
Fig. 32.29 Guided tissue regeneration: (a) Anterior tooth;
periodontium
(b) Posterior tooth

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 578 Essentials of Endodontics

that most of the studies did not evaluate the healing regeneration of periodontal ligament is the key to
potential of GTR in control group, especially where the success of this treatment.
lesion was small.
Indications
Recently, bioabsorbable membrane instead of non-
A chronically infected or severely fractured tooth or
resorbable membrane, has been used in endodontic
missing tooth requiring replacement (any non-
surgery. It is emphasized that GTR therapy, with or
functioning tooth, usually crowded tooth can be taken
without grafts and barrier membrane, significantly
as donor). The third molar tooth replanting into first
improves healing, especially of large lesions.
molar site is common. The teeth most commonly used
as donor are premolars extracted because of orthodontic
Replantation/Intentional Replantation
reasons.
Replantation implies planting avulsed tooth into the
same socket (extraoral time varies, condition of tooth Advantages
depends on patient); whereas, intentional replantation • The tooth continuously maintain alveolar bone and
means extracting the tooth and replanting in the same gingival margins
socket (extraoral time depends on operator). • Prosthesis is avoided
• No need to prepare adjacent tooth
Indications
• Cost-effective.
• Nonsurgical means are not feasible and the tooth
would be extracted Disadvantages
• Patient unable to tolerate or not fit for lengthy • Possibility of resorption and loss of tooth
endodontic surgery. • May lead to ankylosis
Contraindications • Need multidisciplinary approach for better results.
• Non-restorable tooth Decompression of Large Periradicular Lesions
• Severe periodontal disease
The decompression is indicated in case of large lesion
• Widely divergent/dilacerated roots or any abnormal where surgery might devitalize the pulp of an adjacent
morphology, which might lead to crown/root fracture. tooth and nonsurgical treatment would lead to slow
Technique healing (Fig. 32.30).
• Root canal treatment should preferably be completed Technique
before extraction • Fabricate tube with collar (section of intravenous
• Minimize extraoral time (especially, if opt for root tubing). A radiopaque nasogastric tube is preferred
canal treatment after extraction) • Aspirate lesion
• Restore access with amalgam or composites to • Small vertical incision is given into osseous fenestra-
prevent fracture tion
• Extraction should be atraumatic. Avoid injury to
cementum
• Keep tooth moist after extraction, preferably with
Hanks Balanced Salt Solution
• Do not curette walls of socket
• Replant (manually compress cortical plates over
replant)
• Splint, if necessary
• Relieve occlusion
• Prescribe antibiotics to prevent inflammatory
resorption.

Autotransplantation
Autotransplantation is the surgical repositioning of a

32 tooth within the same patient (the socket will be

different). The extracted tooth is implanted in a new,
surgically prepared socket. The preservation and Fig. 32.30 Decompression of large periradicular lesion

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 Surgical Endodontics 579

• Trim tube to fit into depth of lesion without protruding Hemisection/Bicuspidization/Radisectomy

• Insert tube and irrigate with saline (10 ml three times Hemisection refers to cutting the mandibular molar/
a day) two rooted tooth to half and removing one half (used
• Monitor patient weekly and remove tube when no in case where one root cannot be treated endo-
more debris is removed by flushing procedures dontically). In bicuspidization, the mandibular molar/
• Mucosal opening usually heal within one week two rooted tooth is cut into two and both the halves
• Follow resolution of lesion with radiographs. are preserved (used in case of un-managed furcation
perforation). In case of maxillary molars, if only one or
Perforation Repair
two roots need be extracted, the procedure is known
The perforation repair should preferably be carried out as ‘Radisectomy’.
using nonsurgical modalities. In case surgery is The root canal of the healthy root(s) is prepared and
mandatory; bone support of adjacent teeth is not to be
obturated. The crown is bisected into two halves using
sacrificed.
fine bur, moving from lingual to buccal direction
Access and visualization of the defect are essential
(prevents injury to tongue). The discs should be
for successful surgical repair (Fig. 32.31a to d). Usually
avoided. The diseased root is extracted slowly without
only flaps are helpful in managing the perforation
disturbing the healthy one. The socket is curetted and
(up to furcation area). If perforation is deep rooted,
sutured (Fig. 32.32a to f).
bone cutting becomes necessary. The perforation site,
once exposed, is washed thoroughly, excavated of The treated and preserved root(s) is usually prone
any granulation tissue/debris and filled with an to fracture, especially if the occlusal forces are not in
appropriate material. Intentional replantation can be line with long-axis of the root. Do not restore the
considered if access is difficult. hemisected tooth as a cantilever.

a b

32
c d
Fig. 32.31 Perforation repair (a) Preoperative; (b) File in perforation; (c) Sealing/filling of perforation; (d) Repositioning of
flap and suturing

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 580 Essentials of Endodontics

a b

c d

e f

Fig. 32.32 Hemisection procedure: (a) Preoperative (clinical); (b) Preoperative (radiological); (c) Healthy root is prepared
and obturated; (d) Crown is bisected into two halves; (e) Extraction of diseased root; (f) Postoperative radiograph

Electrosurgery • Electrosection is used for incision, excision and tissue

Electrosurgery is a surgical technique performed on soft planing.
tissues using controlled high frequency currents in the • Electrocoagulation provides control of hemorrhage
range of 1.5–7.5 million cycles per second or megahertz. by using electrocoagulation current. (Electrosection
The basic rule of electrosurgery is: always keep the tip and electrocoagulation are most commonly used in
moving. Prolonged/repeated application causes heat all areas of dentistry.)
accumulation and tissue destruction. • Electrofulguration and electrodesiccation are not

32 The commonly used electrosurgical techniques are

electrosection, electrocoagulation, electrofulguration
and electrodesiccation.
used in dentistry.
The types of electrodes and their uses are tabulated
in Table 32.2.

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 Surgical Endodontics 581

Table 32.2 Types of electrodes and their uses Postoperative Care

Type of electrode Use Postoperative care is mandatory after every surgery.
Needle electrode • Removal of gingival enlarge- The patient should be informed of the complications/
ment and gingivoplasty side effects of surgery. The patient is instructed to
• To make incision to establish follow the following protocol (the instructions can be
drainage in treatment of given verbally or in the written form).
acute periodontal abscess • Use ice packs for first day in cycles of 20 minutes.
Needle electrode supple- • Used for festooning • Avoid alcohol, smoking and strenuous activity.
mented by small ovoid loop • During reshaping, the elec- • Initial diet should consist of liquid supplements
or diamond-shaped trode is activating and moved including fruit juices and vitamin supplements.
electrodes in a concise ‘shaving’ motion Sticky food should be avoided.
Thin, bar-shaped electrode • Control of bleeding points • Do not tug or lift facial tissues.
located interproximally • Oozing of blood from surgical site during first
• Electrosurgery is mainly help- 24 hours is normal.
ful for the control of isolated • Postsurgical discomfort may remain.
bleeding points • Take analgesics/antibiotics as advised.
Loop electrode • Relocation of frenum and • Warm saline rinses are advised after 24 hours.
muscle attachments to
facilitate pocket elimination
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following apical surgery in the esthetic zone : a clinical study
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with 70 cases. Eur. J. Esthet. Dent.: 2009; 4:28–45.
60. Tsesis I, Rosen E, Schwartz-Arad D and Fuss Z. Retrospective 73. vonArx T. Apical surgery : a review of current techniques
evaluation of surgical endodontic treatment: traditional versus and outcome. The Saudi Dent. J.: 2011; 23:9–15.
modern techniques. J. Endod.: 2006; 32:412–416.
74. vonArx T. Failed root canals: the case for apicoectomy
61. Tsurumachi T and Kakehashi Y. Autotransplantation of a (periradicular surgery). J. Oral Maxillofac. Surg.: 2005;
maxillary third molar to replace a maxillary premolar with 63:832–837.
vertical root fracture. Int. Endod. J.: 2007; 40:970–978. 75. Von AT, Gerber G and Hardt P. Peririadicular surgery of
62. Velvart P and Peters CL. Soft tissue management in endodontic molars: a prospective clinical study with a 1-year follow-up.
surgery. J. Endod.: 2005; 31:271–274. Int. Endod. J.: 2001, 34:520–525.

32

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 Chapter
33
Endodontic Implants

Preservation of natural dentition so as to achieve

functional stomatognathic system is the main goal of
restorative dentistry. Advanced caries and periodontal
diseases may warrant the need of intrabone implant to
stabilize the tooth and/or to improve the crown-root
ratio. There are basically two types of implants;
prosthetic implants that replace the missing tooth/root
and endodontic implant that use the remaining tooth/
root for anchorage.
An endodontic implant is a metallic extension of the
root (Fig. 33.1), executed with the object of increasing
the root-to-crown ratio so as to provide better stability
to the tooth in the arch; subsequently maintaining the
stomatognathic system (Fig. 33. 2). Fig. 33.2 Crown: Root ratio

Endodontic implants are also known as endodontic

stabilizers, diodontic implants and endosseous endo-
dontic implants. The endodontic implants increase the
root anchorage in the bone by extension of the selected
metal/material into the alveolar bone, stabilizing teeth
with compromised alveolar support. As compared to
prosthetic implants, endodontic implants are
considered better since, these implants do not
communicate with oral environment (separation from
oral cavity reduces the complication of periodontal
breakdown; one of the main cause of implant failure).
Endodontic stabilizers have also been utilized in
stabilizing two fractured root segments (Fig. 33.3).

Indications
The indications of endodontic implants are:
• Periodontally involved teeth requiring stabilization
• Transverse root fracture indicating removal of apical
fragment, reducing the crown-root ratio
• Pathologic resorption of the root apex
• A pulpless tooth with an unusually short root
• Abutment teeth with inadequate root length
• A tooth in which additional root length is desired
Fig. 33.1 Endodontic implant for improving its alveolar support

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 Endodontics Implants 585

PATIENT SELECTION
The criteria used for patient selection requiring endo-
dontic implants are:
i. Periodontal status of the tooth: Aggressive
periodontal problem with continuous loss of bone
may lead to failure of endodontic implants. The
periodontal therapy is to be instituted with or
without grafting to ensure complete healing of
periradicular bone. The active periodontal problem
may also lead to soft tissue breakdown, facilitating
communication of the implant with the oral cavity.
This communication, if not managed at the initial
a b
stage may lead to failure of endodontic implant
therapy.
ii. Anatomical considerations: Anatomical structure,
such as maxillary sinus, mental foramen, inferior
alveolar canal may get violated during insertion of
implant, especially when in near proximity to the
apex of root. The inclination of root apex in the
alveolar bone should also be evaluated before
placing the endodontic implant.
iii. Patient’s acceptance: Patient selection is most
important consideration for implant placement.
Patient should be informed of all the implications
c d
involved during and after implant placement. The
prognosis and longevity of the procedure should
Fig. 33.3 Stabilizing two fractured root segments (a) Pre- be clear to the patient prior to opting for implant
operative; (b) Assessing root canal; (c) Endodontic
stabilization; (d) Postoperative (splinting)
therapy.
(Endodontic implants are not appropriate for all teeth
• Apicoectomy where large portion of apical root is lost that are mobile; and their placement may not resolve the
• Primary molars with no permanent successors advancing periodontal disease.)
• Grade II and III mobility iv. Occlusal interference: It is established that occlusal
• Certain mobile reimplanted teeth interferences affect treatment outcome in endo-
dontic implants. Teeth in maximum occlusal inter-
• Concomitant internal/external resorption leading to
relationships exhibit more mobility after placement
sacrificing apical portion of root.
of endodontic implants than those with no occlusion
Contraindications or at least minimum occlusal interference.
The contraindications for the use of endodontic v. Clinician’s skill: The skill/competence of operator
implants are: is also very important. The clinical information
should be gathered and evaluated for each case in
• Periapical rarefaction/bone infection
order to determine whether endodontic implant
• Previous radiation of the apical area
would be best and the last choice. And also the
• Periodontal pockets communicating with the apical operator would be able to perform the treatment
region procedure with precision.
• Debilitating systemic conditions
• Roots with excessive curvatures Implant Materials and Designs
• Failed root canal treatment cases The success of endodontic implant therapy mainly
• Inadequate vertical bone beyond the apex of tooth depends upon the material and the design of the
(minimum 6.0 mm bone required for implants) implant.
• Anatomic structures approaching apex, such as
maxillary sinus, inferior alveolar canal, mental
foramen, etc. which are liable to be violated.
Initially, vitallium (alloy of 65% cobalt, 30% chromium
and 5% molybdenum) had been widely used as
endodontic implant, considering it to be inert and
33

t.me/Dr_Mouayyad_AlbtousH
 586 Essentials of Endodontics

non-corrosive. Later, investigators questioned the use • The implant/stabilizer should effectively fix into the
of vitallium and also observed that it undergoes surface jaw bone and get stabilized.
corrosion. These observations lead to discontinuation • The effective growth of bone around the implant
of vitallium as endodontic implant material. provides necessary retention.
Currently, two materials are being used as endo-
dontic implants; Titanium and aluminium oxide, which Clinical Criteria for a Successful Endodontic Implant
is a single crystal sapphire. Titanium is biocompatible The success of endodontic implant therapy depends on
and exhibits superior physical properties. Stainless steel various factors. The factors, which affect the long-term
and Ni-Ti in the form of root canal files have also been success of implants are:
used as endodontic implants. • A radiographically normal attachment apparatus
The designs of endodontic implants currently in use including the bone, cementum, and dentin.
are smooth-taper and threaded-taper. Another design • A stabilized functional, and symptomless tooth.
of endodontic implant, the porous surface implant, is • Normal gingival crevice containing a normal
also under investigation (Fig. 33.4 ). The clinical success epithelial attachment.
of smooth and threaded implants is almost same; both • The implant can be inserted through the prepared
provide substantial fixation and adequate stress root canal up to the desired distance in the bone and
distribution to the surrounding tissues. Threaded remain there between the labial and lingual plates
implants displayed higher retention; however, the of bone.
threads cutting into apical dentin may lead to high • Sufficient alveolar bone should be available for
stresses and even microcracks in dentin, subsequently retention and stability of both the tooth and the
leading to root fracture and failure of implant therapy. implant.
Porous surface implant provides strong fixation by • Teeth with multiple canals, curved canals/curved
facilitating bony ingrowths. These implants also root apices, calcified/obstructed canals should be
provide better retention in the root canal and better seal avoided whenever possible.
as well. Glass-ionomer and AH 26 cements provide • Caution must be exercised to avoid implant penetra-
better mechanical interlocking at cement-implant tion into the mandibular canal, maxillary sinus, etc.
interface. Possibility of using aluminium, molybdenum • Teeth with insufficient bone support and a hopeless
with titanium for endodontic implant material is under periodontal prognosis are poor candidate for
investigation; porous surface design is showing endodontic implant.
promising results. The limitations of endodontic implants, which can
The efficacy of endodontic stabilizer depends upon result in failure, are:
following considerations: • Poor apical seal resulting in periapical rarefaction
• The implant/stabilizer should provide effective around the root apex.
apical seal; seal at the apical zone area. • Extrusion of excessive sealer through the apical
foramen into the periapical tissues; with resulting
• The implant/stabilizer should remain retentive in the irritation.
root canal.
• Limitation in the available length of the osseous
portion of implants by local anatomic factors, such
as the maxillary sinus, mandibular canal, etc. The
labioversion/linguoversion of the tooth in the jaw
also pose challenge.
• Perforation of the lateral root surface or perforation
of a curved root near the root apex.
• A structurally weakened tooth, instrumented to a
larger size than usual may fracture during function.
Three-dimensional apical seal is important feature
for the success of implant therapy. In preparing a wide
apical foramen, the root apex is ground away by the
large endodontic instruments, which may lead to

33 Fig. 33.4 Endodontic implants (surface variations)

fracture the root tip or subsequently resorption of the
root tip at a later stage. The result is an imperfect apical
seal, which would lead to failure of the implant therapy.

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 Endodontics Implants 587

IMPLANT PLACEMENT • Seat the implant by pressing the plugger firmly

The root canal is prepared following the conventional against the butt end of the implant, until it binds
principles. In case the tooth is mobile (grade II mobility), completely in the canal and the bone.
the same should be splinted prior to root canal The rest of the space can be utilized for back-filling
treatment. The access preparation should be larger and or postcore restoration depending on the remaining
wider so as to accommodate the placement of a rigid tooth structure, esthetics and the patient’s expectations.
implant that requires ‘straight-line’ insertion into the
canal. The root canal must be enlarged to at least the BIBLIOGRAPHY
size of a No. 60 instrument. The steps followed in 1. Cardenas JE, Beltran EH and Ananos FH. Ni-Ti endodontic
implant placement are: intraosseous implant. Dent. Press. Endod.: 2012; 2:38–41.
• Anesthetize the tooth and the surrounding areas. 2. Chen H, Liu N, Xu X, Qu X and Lu E. Smoking, radiotherapy,
diabetes and osteoporosis as risk factors for dental implant
• A marker is set on the 40 mm reamers at a level failure: a meta-analysis. PLoS ONE: 2013; 8:e71955.
equivalent to the length of the tooth plus the number 3. Goldberg F. Endodontic implant: a scanning electron
of millimetres the implant will extend beyond the microscopic study. Int. Endod. J.: 1982; 15:17–78.
root apex. 4. Konake VB and Patil SN. Management of grade III mobile
• The first 40 mm reamer used to perforate the root anterior tooth in function using endostabilizer – a case report.
apex should be smaller than the last sized instrument, J. Crit. And Diag. Res.: 2014; 8:6–7.
which was used to prepare root canal. 5. Larsen RM, Patten JR and Wayman BE. Endodontic
endosseous implants: case report and update of materials. J.
• The last 40 mm reamer should be of the size of last Endod.: 1989; 15:496–500.
endodontic instrument; the bone is pierced to the 6. Madison S and Bjorndal AM. Clinical application of
desired length. endodontic implants. J. Prosthet. Dent.: 1988; 57:603–608.
• Irrigate the root canal preferably with anesthetic 7. Maniatopoulos C, Pilliar RM and Smith DC. Evaluation of
solution, which débrides as well as controls hemorr- the retention of endodontic implants. J. prosthet. Dent.: 1988;
59:438–446.
hage within a few minutes.
8. Marchand F, Raskin A and Dionnes-Hornes A. Dental
• The canal is dried using sterile absorbent points. implants and diabetes: conditions for success. Diabetes
• Select an implant of equivalent size to the last Metab.: 2012; 38:14–19.
instrument used; the desired length is marked from 9. Mittal S, Kumar T, Aggarwal V, Bansal R and Kaur D.
the occlusal tip through the root canal to the exact Endodontic stabilizers for treating mid root fractures. J.
length cut into the cancellous bone, and insert it into Interdiscip. Dent.: 2011; 1:108–110.
10. Nivethithan T, Ramesh S and Raj JD. Endodontic stabilizers:
the bone through the root canal.
A myth. Int. J. Pharma. Resch. Clin. Res.: 2015; 7:1–7.
• The implant must penetrate into the bone up to the 11. Parmar G and Pramodkumar AV. Custom-fabricated endodontic
prepared length and should be tightly fit. implants: report of two cases. J. Endod.: 2000; 26:301–303.
• If necessary, enlarge the root canal a little more to 12. Pereira FR, Brawuel JD, Roahen JO and Giambarresi L.
accommodate the implant, but the implant must fit Histological response to titanium endodontic endosseous
snugly at the apical foramen. implant in dogs. J. Endod.: 1996; 22:161–164.
13. Priyadarshini L and Narayan L. Endodontic miscellany: Use
• Insert a plugger into the canal opening until it binds, of an endodontic file as an endodontic implant.
and measure the exact length; the implant can be Endodontology: 2000; 12:37–39.
inserted unimpeded into the canal. 14. Sahelipour F. Endodontic stabilizers. J. Endod.: 2005; 18–21.
• Using a diamond/carborundum disc, cut the butt 15. Sumi Y, Mitsudo K and Ueda M. Conservation of severely
end of the implant and adjust length equivalent to traumatized teeth using endodontic implants: A case report.
the measurement obtained by inserting the plugger J. Oral Maxillofac. Surg.: 1998; 56:240–242.
into the root canal. 16. Sumi Y, Nakamura Y, Mitsudoh K and Ueda M. Application
of titanium-alloy endodontic implants in conjunction with
• This plugger is used to push the implant, because periradicular surgery. Oral Surg., Oral Med., Oral Pathol.,
the butt end of the implant must be cut-off prior to Oral Radiol. Endod.: 1999; 88:484–7.
insertion into the tooth. 17. Sussman HI. Endodontic pathology leading to implant failure.
• Glass-ionomer cement or AH 26 cement is preferred A case report. J. Oral Implantol.: 1997; 23:112–116.
for cementation. Apply cement into the dried canal 18. Torabinejad M and Goodacre CJ. Endodontic or dental
implant therapy: the factor affecting treatment planning.
and try to avoid cement extrusion beyond the apical
JADA: 2006; 137:973–977.

33
foramen. 19. Yadav RK, Tikku AP, Chandra A, Wadhwani KK, Kumar A
• Using a hemostat, push the implant slowly into the and Singh M. Endodontic implants. Nat. J. Maxillofac. Surg.:
canal and bone. 2014; 5:70–73.

t.me/Dr_Mouayyad_AlbtousH
Chapter
34
Endodontic–Periodontal
Relationship

Each specialty of dentistry stands at a point where the perforations of the floor of pulp chamber, strip
patient care approach makes it mandatory to be perforations/root perforations, etc. Periodontal defects
involved with other specialties right from the phase of may also be caused by vertical root fractures, mostly
diagnosis to treatment planning and finally to that of associated with excessive force used during obturation
maintenance. The specialties have been created for of canal spaces.
convenience to focus the knowledge on particular areas; The by-products of pulpal inflammation often lead
however, for the benefit of patients, the interrelated to inflammation in the periodontal tissues. Inflamma-
areas should also be looked into and discussed. tion in the infected pulp produces by-products that pass
Pulpal and periodontal problems are responsible for along the pathways of communications and elicit an
more than 50% of tooth mortality. The main pathways inflammatory reaction in the periodontium. Similarly,
for communication between the dental pulp and the inflammatory by-products of the infected perio-
periodontium are through lateral/accessory canals, dontal tissues can cause infection in the pulp. This is a
apical foramen and also the dentinal tubules. The vicious cycle that continues and often creates a dilemma
pathways of communications between pulp and for the clinician. A few authors are of view that
periodontium often determine the progress of disease periodontal disease would not cause pulpal disease
in these tissues. because inflammation follows venous drainage and
Endodontic–periodontal (Endo–Perio) relationship the venous blood flows outward from the pulp to the
implies the spread of inflammation and infection from periodontium. Bacteria, viruses and fungi are the
one component to the other (spread of infection from pathogens from diseased pulp that can cause perio-
endodontic lesion to periodontic tissues and from dontal lesions.
periodontic lesions to endodontic tissues). Thorough
knowledge of Endo–perio relationship is crucial for Bacteria
proper diagnosis and treatment decision-making in Bacteria play a critical role in both endodontic and
diseases affecting these tissues. periodontal diseases.
Initially proteolytic bacteria predominate in the root
PERIODONTAL PULPAL INTERRELATIONSHIP canals; later, anaerobic microbiota becomes prevalent.
The pulp is generally not affected by periodontal Spirochetes though associated with both endodontic
disease until the defect exposes accessory canal(s) to and periodontal disease, are found more in subgingival
the oral environment. The pathogens may pass through plaque than in root canals. A large diversity of oral
these open accessory canals into the pulp and cause a treponemas in subgingival biofilms of periodontal
localized inflammatory response, which may lead to pocket has been identified; therefore, it was thought
pulpal necrosis. Certain procedures involved in root that the presence or absence of oral spirochetes can be
canal treatment, such as irrigants, intracanal medica- used to differentiate between endodontic and
ments, sealers, etc. if come in contact with periodontal periodontal lesions. However, the presence of
tissues may lead to inflammatory response in the spirochetes in the root canal has been well-documented
periodontium. by different identification techniques. The spirochete
Periodontal defects may occur after procedural species most frequently found in root canals are
mishaps during root canal preparations, such as Treponema denticola and Treponema maltophilium.

588

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 Endodontic–Periodontal Relationship 589

Bacteria associated with Pulp Diseases produce changes in the periodontal tissue; however, in
• Spirochetes some cases the pulpal inflammation may extend into
• Eubacteria the periodontium, e.g. a long-standing periapical
• Peptostreptococci abscess may drain through gingiva producing a
periodontal pocket. This pocket formation is different
• Fusobacterium
from the common periodontal pocket and is termed
• Porphyromonas
‘retrograde periodontitis’. The increased tension within
• Prevotella the pulp chamber may facilitate passage of infected
• Streptococci material into the periodontium along the pathways of
• Lactobacillus communications, thereby spreading the disease.
• Actinomyces.
Effect of Periodontal Disease on the Pulp
Bacteria associated with Periodontal Lesions The pulpal diseases when initiated as a result of
• Actinobacillus actinomycetemcomitans extension of infection from the periodontal tissue into
• Porphyromonas gingivalis the pulp, are termed ‘retrograde pulpitis’. During
• Bacteroides forsythus the root planing procedures, cementum may get
• Prevotella intermedia exfoliated, exposing the dentinal tubules. The exposed
• Streptococcus intermedius dentinal tubules create direct pathway between
• Fusobacterium nucleatum the periodontium and the pulp. It is established that
• Treponema denticola periodontal disease can produce atrophic changes like
calcification and deposition of secondary dentin in the
• Eubacterium spp.
pulp.
Fungi
Candida albicans, Candida glabrata, Candida guillermondii, CLASSIFICATION OF ENDODONTIC PERIODONTAL
Candida incospicia and Rodotorulamucilaginosa are the LESIONS
common fungi species found in pulpal diseases. The endodontic-periodontal lesions have been classified
The reduction of specific strains of bacteria in the by different authors. The accepted classifications are:
root canal during endodontic treatment may allow
fungal overgrowth in the remaining low nutrition 1. Simon’s/Cohen’s Classification
environment. Fungi may gain access to the root canal a. Primary endodontic lesions
from the oral cavity as a result of poor asepsis during b. Primary periodontal lesions
endodontic treatment or postpreparation procedures. c. Combined lesions
It has also been established that approximately 20% of i. Primary endodontic disease with secondary perio-
periodontitis patients harbor subgingival yeasts. dontal involvement
ii. Primary periodontal disease with secondary endo-
Viruses
dontic involvement
In patients with periodontal disease, herpes simplex iii. True combined diseases.
virus was frequently detected in the gingival crevicular
fluid and in the gingival biopsies of periodontal lesions. 2. Grossman’s Classification
Human cytomegalovirus may be present in about 65% a. Lesions that require endodontic treatment proce-
of the periodontal pocket samples and in about 85% of dures only
gingival tissue samples. Epstein-Barr virus Type 1 may
i. Periapical abscess
be present in more than 40% of pocket samples and in
ii. Root fractures
about 80% of the gingival tissue samples. Active virus
infection may give rise to production of an array of iii. Root perforations
cytokines and chemokines with the potential to induce • Teeth with incomplete root formation
immunosuppression and tissue destruction. • Pulp exposures
b. Lesions that require periodontal treatment proce-
Effect of Pulpal Disease on Periodontium dures only
i. Occlusal trauma
Pulpal tissue is enclosed in the pulp chamber and is
separated from the periodontal tissue by dentin and
cementum. The diseases of the pulp normally do not
ii. Gingival inflammation
iii. Periodontal pocket formation
34

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 590 Essentials of Endodontics

c. Lesions that require combined endodontic perio- necrosis does not cause periodontal disease directly;
dontic treatment procedures however, it may form sinus tract, which allows passage
i. Root resorption of inflammatory products to the periodontal ligament.
ii. Replants, transplants, etc. Osseous destruction is localized to the involved tooth.
• Surgical intervention b. Primary periodontal lesions
• Concomitant pulpal and periodontal involvement. The periodontal lesions usually initiate in the sulcus
and migrate apically (Fig. 34.2a to c). The plaque induced
3. Weine’s Classification
inflammation, lead to loss of surrounding alveolar bone
a. Class I: Tooth in which symptoms clinically and radio- and supporting periodontal soft tissues. The loss of
graphically simulate periodontal disease; but are clinical attachment of periodontal tissues initiates
actually due to pulpal inflammation and/or necrosis. periodontal problems; subsequently, progression of
b. Class II: Tooth that has concomitant pulpal/periapical periodontal disease leads to the formation of osseous
and periodontal disease. defects along the lateral and furcation areas.
c. Class III: Tooth that has no pulpal problem but requires The affected tooth has vital pulp and responds
endodontic therapy (may need root amputation also) normally on pulp testing.
to achieve periodontal healing.
d. Class IV: Tooth that clinically and radiographically c. Combined lesions
simulates pulpal/periapical disease; but actually has i. Primary endodontic lesions with secondary periodontal
periodontal disease. involvement: An untreated or poorly treated endodontic
lesion usually lead to destruction of the periapical
Simon’s/Cohen’s classification, based on pathology of
tissues; subsequently, this destruction progresses
origin of the lesion, is accepted and is described:
into the interradicular area. The persistent drainage
a. Primary endodontic lesion from gingival sulcus coupled with accumulation of
Primary endodontic lesion is originally an endodontic plaque/calculus results in periodontal disease and
lesion; the inflammatory by-products proceed from further apical migration of epithelial attachment
pulp spaces to the gingiva (Fig. 34.1a to c). Pulpal (Fig. 34.3a to c).

a b c
Fig. 34.1 Primary endodontic lesion: (a) Diagrammatic; (b) and (c) Radiographic

34
a b c

Fig. 34.2 Primary periodontal lesion (chronic periodontitis progresses apically along the root surface): (a) Diagrammatic;
(b) Radiographic (premolars); (c) Radiographic (incisors)

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 Endodontic–Periodontal Relationship 591

a b c

Fig. 34.3 Primary endodontic lesion with secondary periodontal involvement: (a) Diagrammatic; (b) Radiographic;
(c) Case-treated with root canal therapy and bone grafting

a b c

Fig. 34.4 Primary periodontal lesion with secondary endodontic involvement: (a) A periodontal pocket can infect the
pulp through a lateral canal (blue arrow) and this in turn can result in a periapical lesion (diagrammatic); (b) Radiographic;
(c) Case-treated with root canal therapy and curettage

These lesions usually have necrotic root canals and

plaque/calculus accumulations can be seen clinically.
Radiographs may show generalized periodontal defects
at the initial site of endodontic involvement.

ii. Primary periodontal lesions with secondary endodontic

involvement: Periodontal disease can have an effect on
pulp through accessory/lateral canals or even through
exposed dentinal tubules (Fig. 34.4a to c). Progressive
osseous destruction due to periodontal disease can
expose dentinal tubules, lateral accessory canals and
the furcation area. Thus, a periodontal pocket can infect
the pulp, subsequently resulting in a periapical lesion.
Primary periodontal lesions with secondary endo-
dontic involvement usually exhibit pain and clinical
signs of pulpal disease. This situation is evident when Fig. 34.5 Fisiograft
the periodontal disease progresses to expose the pulp
to oral environment, generally leading to necrotic pulp. clinically indistinguishable and are known as ‘True
Combined lesions’.
The periodontally involved maxillary lateral incisor
was treated with Fisiograft (Fig. 34.5) and root canal
therapy (Fig. 34.6a to e). DIAGNOSIS
The pulp is vital and responsive to pulp testing in
iii. True combined lesions: Pulpal and periodontal disease periodontal diseases; whereas, it is mostly infected and
may occur independently or concomitantly in and non-responsive in endodontic diseases. When the
around the same tooth (Fig. 35.7a to c). Two indepen- location is distinct and the lesion is discrete, the two

34
dent periapical and periodontal lesions can coexist and can easily be differentiated. Once both the lesions
may eventually fuse with each other. Once the separate progresses simultaneously or one affects the other, the
endodontic and periodontal lesions coalesce, they are diagnosis becomes challenging. Usually a similar

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 592 Essentials of Endodontics

a b c

d e
Fig. 34.6 Clinical management of maxillary lateral incisor (primary periodontal lesion with secondary endodontic
involvement) (a) Preoperative; (b) Flap raised; root canal opened; (c) Curettage of bony defect; (d) Placement of
fisiograft (after root canal completion); (e) Coapting the flap and suturing

a b c

Fig. 34.7 True combined lesion: (a) Diagrammatic; (b) Radiographic (molar); (c) Radiographic (incisor)

clinical and radiological features are evident with both; The suggestive treatment is described as per Simon’s/
a periapical lesion with secondary periodontal involve- Cohen’s classification of Endodontic–Periodontal lesions.
ment and a periodontal lesion progressing to the apical
area. The criteria of clinical identification of endodontic- Treatment: Key Features
periodontal lesions are tabulated in Table 34.1. The • A few authors suggest that initial treatment be either
differentiation of sinus tract from an infrabony pocket endodontic or periodontal depending on origin of the
initiating disease.
is depicted in Table 34.2. The diagnostic features of both
• Others recommend that endodontic treatment should be
pulpal and periodontal lesions are given in Table 34.3. initiated followed by periodontal therapy; once a successful
In case diagnosis cannot be established, the lesion is consi- periodontal result has been achieved, the endodontic
dered to be of pulpal origin (an endodontic treatment can treatment is finalized.
correct both lesions). • It is suggested that endodontic treatment should precede
periodontal therapy, regardless of the cause of the disease;
however, on exceptional occasions, the periodontal proce-
TREATMENT
34
dures should precede the endodontic treatment, such as
The treatment decision-making depends on diagnosis when an unexpected need arises for radisectomy of a multi-
of pulp vitality and extent of the periodontal defect. rooted tooth, exposed during periodontal surgical procedure.

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 Table 34.1 Clinical identification of endodontic–periodontal lesions
Examination/diagnostic Primary endodontic Primary periodontal Primary endodontic Primary periodontal True combined
tests lesion lesion lesions with secondary lesions with secondary lesion
periodontal involvement endodontic involvement
Visual examination Presence of deep carious Accumulation of plaque Root perforation/fracture Presence of plaque/ sub Presence of varying degree
lesion/large-old restoration/ and subgingival calculus of root/post placed away gingival calculus around of periodontitis.
fractured restoration/ around multiple teeth/ from root canal. Seeping multiple teeth. Presence of pus exudate
abrasion/cracks. Sinus inflamed gingiva. of exudate at the gingival Presence of generalized along with chronic dis-
opening may be present Presence of swelling margin of the affected gingival recession colored (nonvital) tooth.
around any tooth (indicat- tooth. Seeping of exudate from
ing periodontal abscess) affected teeth.
Pain Sharp Usually dull ache; abscess Usually sharp pain; chronic Usually dull ache; Usually dull ache
may present sharp pain conditions present dull Acute periodontal abscess (combined lesions are
ache present sharp pain usually chronic)
Palpation Usually no response Tender on palpation Tender on palpation Tender on palpation Tender on palpation
(chronic periradicular
inflammation may
response positively)
Percussion Tender on percussion Usually not tender (acute Tender on percussion Tender on percussion Tender on percussion
case may response)
Tooth mobility Fractured tooth/recently Presence of localized/ Presence of localized Presence of generalized Presence of generalized
traumatized teeth show generalized mobility mobility mobility mobility
mobility
Pulp vitality testing A lingering response- The pulp is vital and Pulp vitality tests negative Pulp vitality may be posi-
Usually negative because
irreversible pulpitis responsive to testing tive in multirooted teeth
of nonvital pulp. Vitality tests
No response-necrotic may give positive response
pulp (nonvital) in multirooted teeth
Periodontal pocket Presence of a solitary Multiple deep perio- Presence of periodontal Presence of multiple deep Periodontal pockets in
evaluation periodontal pocket in the dontal pockets pocket along the affected periodontal pockets association with endo-
absence of generalized tooth (teeth) dontically involved teeth

t.me/Dr_Mouayyad_AlbtousH
periodontitis.
(Such pocket may be
seen in case of a vertical
root fracture)
Radiographic sinus tracing Gutta-percha point Gutta-percha mainly Gutta-percha mainly at Gutta-percha mainly
Sinus tract (gutta-percha)
using gutta-percha points approaching apical depicted at the lateral the apical area or depicted at the lateral
may not detect the lesion.
area or furcation area aspect of the root furcation area aspect of the rootFlap is to be raised to deter-
in molars mine the exact etiology.
Conventional radio- Presence of deep carious Generalized vertical bone Presence of deep carious Generalized angular bone Generalized bone loss
graphic evaluation lesions/extensive, old and loss lesions/extensive, old and loss along with features of
defective restorations/poor defective restorations/poor endodontic lesions.
root canal management/ root canal treatment/root
root fractures. fractures.
Periapical radiolucency Periapical radiolucency
may and may not be usually present.
present.
Evaluating cracked tooth Painful response while No symptoms Painful response while No symptoms Painful response while
Endodontic–Periodontal Relationship

(teeth) chewing a wooden/ chewing a wooden/ chewing a wooden/rubber

rubber platform; on rubber platform; on platform; on releasing the
releasing the biting releasing the biting biting pressure, pain
593

pressure, pain increases. pressure, pain increases. increases.

34
 594 Essentials of Endodontics

Table 34.2 Differentiation of a sinus tract from an infrabony pocket

Sinus tract Infrabony pocket
Origin Originates from root canal and progresses occlusally Originates from gingival crevice and progresses apically
from apical foramen or from a lateral canal
Diagnosis By means of gutta-percha cone or diagnostic wire Periodontal probe
Treatment Endodontic therapy Periodontal therapy (endodontic therapy may be
required)

Table 34.3 Differential diagnosis of pulpal and periodontal disease

Pulpal Periodontal
Clinical
Cause Pulpal infections Periodontal infections
Vitality Nonvital Vital
Restoration Deep or extensive Not related
Plaque/calculus Not related Primary cause (must be present)
Inflammation Usually acute, become chronic later Usually chronic
Periodontal pockets Not related Deep/multiple
pH value Often acidic Often alkaline
Trauma May lead to pulpal disease Contributing factor
Flora Few Complex
Radiological
Pattern Localized Generalized
Bone loss Wider apically Wider coronally
Periapical Radiolucent Not often related
Vertical bone loss No Yes
Histopathological
Junctional epithelium No apical migration Apical migration
Granulation tissue Minimal larger
Gingiva Normal Usually recession

a. Primary Endodontic Lesions periodontal therapy. Poor restorations and develop-

Primary endodontic lesions usually heal following root mental grooves that are involved in the lesion must be
canal treatment. Prognosis is always better in properly removed. Periodontal surgery should be performed
executed root canal treatment. The sinus tract extending after the completion of hygiene phase of the treatment.
into the gingival sulcus/furcation area, if present, The surgical periodontal procedures may remove
disappears once the treatment is completed. Calcium cementum and expose dentinal tubules, (transporting
hydroxide as an intracanal medicament, has been irritants and causing pulpal inflammation); should be
effective in the healing of large periapical lesion carried out judiciously. The clinicians should take
[Calcium hydroxide damages the microbial cytoplasmic precautions during periodontal therapy and avoid the
membrane, suppresses enzyme activity, disrupts the use of irritating chemicals so as to minimize damage to
cellular metabolism and inhibits deoxyribonucleic acid cementum. Judicious use of periodontal surgical
(DNA) replication by splitting DNA]. It also acts as a intervention can be effective.
physical barrier that fills the space within the root canal Flowchart 34.1 summarizes the treatment of
walls and kills the remaining microorganisms by endodontic–periodontal lesions.
withholding substrates for their growth. In case of large
c. Combined Lesions
periapical radiolucency, surgical intervention can be
effective. i. Primary endodontic lesion with secondary perio-
dontal involvement
b. Primary Periodontal Lesions The prognosis for treatment of primary endodontic

34 Primary periodontal lesions are treated by appropriate

periodontal therapy. The prognosis depends on the
severity of the periodontal disease and the efficacy of
lesion with secondary periodontal involvement
depends primarily on the severity of periodontal
involvement. Such lesions should first be treated with

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 Endodontic–Periodontal Relationship 595

Flowchart 34.1: Stepwise treatment of endodontic–periodontal lesions

endodontic therapy followed by conventional periodontal treatment. Primary endodontic lesions with
periodontal treatment. Multivisit endodontics should secondary periodontal involvement may also occur as
be preferred placing intracanal medicament. The a result of iatrogenic damage, such as root perforation
reduction in inflammation followed by repair should or root fracture during root canal treatment. The
be evaluated periodically and then further periodontal outcome of the treatment of root perforations depends
treatment should be initiated. This way effect of pulpal on the size, location, time of diagnosis and the degree
inflammation on periodontal tissues can be evaluated. of periodontal damage. It has been recognized that the
It is established that aggressive removal of the success of the treatment depends mainly on immediate
periodontal ligament and underlying cementum during sealing of the perforation and appropriate infection
initial endodontic therapy may adversely affect the control. Root fractures may also present as primary
periodontal healing. If the endodontic treatment is
adequate, the prognosis depends on the severity of the
periodontal tissue damage and the efficacy of
endodontic lesions with secondary periodontal
involvement. Treatment depends on the tooth type,
extent, duration and location of fracture, e.g. vertical
34

t.me/Dr_Mouayyad_AlbtousH
 596 Essentials of Endodontics

root fracture of single rooted teeth has a poor prognosis, 3. Dahle UR, Tronstad L and Oslen I. Characterization of new
while molars can be managed by root resection/ periodontal and endodontic isolates of spirochetes. Eur. J.
hemisection. Innovative techniques to treat and retain Oral Sci.: 1996; 104:41.
anterior teeth have been attempted using removal of 4. Goyal L. Clinical effectiveness of combining platelet rich fibrin
with alloplastic bone substitute for the management of
the fractured segment followed by endodontic therapy combined endodontic periodontal lesion. Restor. Dent.
or to bond the fractured fragments using a Endod.: 2014; 39:51–55.
biocompatible material. 5. Harrington GW, Steiner DR and Ammons WF. The
periodontal-endodontic controversy. Periodontol2000.: 2002;
ii. Primary periodontal lesions with secondary 30:123–130.
endodontic involvement 6. Heijl L, Heden G, Svardstrom G and Frank AL. Enamel matrix
Primary periodontal lesions with secondary endodontic derivative (EMDOGAIN) in the treatment of intrabony
involvement usually require both endodontic and periodontal defects. J. Clin. Periodontol.: 1997; 24:705–714.
periodontal treatment. The periodontal lesions are 7. John V, Warner NA and Blanchard SB. Periodontic-
treated first (at least partially completed before Endodontic interdisciplinary treatment—A case report.
initiating root canal treatment); may be by conventional, Compendium: 2004; 25:179–185.
surgical and/or regenerative treatment protocol. In case 8. Oh SL, Fouad AF and Park SH. Treatment strategy for guided
tissue regeneration in combined endodontic-periodontal lesions:
of extensive periodontal lesion, splinting is advised
Case report and review. J. Endod.: 2009; 35:1331–1336.
for better results. The prognosis for such lesions is 9. Parolia A, Gait TC, Porto IC and Mala K. Endo–perio lesion:
favorable. A dilemma from 19th until 21st century. J. Interdisc. Dent.:
2013; 3:2–11.
iii. True combined lesion
10. Paul BF and Hutter JW. The endodontic–periodontal
True combined lesions should be treated as primary continuum revisited: new insights into etiology, diagnosis and
endodontic lesions with secondary periodontal treatment. J. Am. Dent. Assoc.: 1997; 128:1541.
involvement. Periodontal therapy should be completed 11. Rostein I and Simon JH. Diagnosis, prognosis and decision-
followed by root canal treatment. The prognosis of true making in the treatment of combined periodontal-endodontic
combined lesion is usually poor, especially in extensive lesions. Periodontol.: 2002, 2004:34:165–203.
periodontal lesions. The prognosis of combined lesions 12. Rotstein I and Simon JH. The endo–perio lesion: A critical
mainly rests with the efficacy of periodontal therapy. appraisal of the disease condition. Endod. Topics.: 2006;
13:34–56.
A tooth that requires a root to be resected always need
13. Rupf S, Kannengiesser S, Merte K, Pfister W, Sigusch B and
root canal treatment; therefore, judicious planning is
Eschrich K. Comparison of profiles of key periodontal
important as regard root amputation/hemisection. pathogens in the periodontium and endodontium. Endod.
Ideally, the tooth should be root filled prior to surgery. Dent. Traumatol.: 2000; 16:269.
The prognosis of an affected tooth can be improved by 14. Shenoy N and Shenoy A. Endo-perio lesion: diagnosis and
increasing bony support, using bone grafting and clinical considerations. Ind. J. Dent. Res.: 2010; 21:579–585.
guided tissue regeneration (GTR). GTR therapy has 15. Simon JHS, Glick DH and Frank AL. The relationship of endo-
been successfully carried out in the endodontic surgeries dontic–periodontal lesions. J. Periodontal: 1972; 43:202–208.
as a concomitant treatment during the management of 16. Singh P. Endo–Perio Dilemma: A brief review. Dent. Res. J.
the endodontic-periodontal lesions. The regenerative (Isfahan): 2011; 8:39–47.
procedure is planned after verifying the nonvital status 17. Siquiera JF and Sen BH. Fungi in endodontic infections. Oral
Surg. Oral Med. Oral Pathol.: 2004; 97:632.
of the pulp, extent and severity of the periodontal
18. Somanath G, George G, Sinha JN and Gautam V. Inter-
destruction, and also prognosis of the planned disciplinary approach in treatment of endodontic–periodontal
regenerative procedure. In case the prognosis of the lesion: A case report. J. Univ. Coll. Med. Sci.: 2013; 1:58–61.
periodontal regenerative procedure is found to be 19. Sunitha VR, Emmadi P, Namasivayam A, Thyegarajn R and
favorable, then endodontic therapy should be initiated. Rajaraman V. The periodontal–endodontic continuum: A
A few authors suggest splinting of concerned tooth review. J. Conserv. Dent.: 2008; 11:54–62.
(teeth) before GTR procedure and root canal treatment. 20. Taschieri S, Del Fabbro M, Testori T, Saita M and Weinstein
Root canal treatment does help reducing the mobility R. Efficacy of guided tissue regeneration in the management
of tooth. Long-term follow-up is necessary to assess of through-and-through lesions following surgical
endodontics: A preliminary study. Int. J. Periodontics
treatment success in such lesions. Restorative Dent.: 2008; 28:265–271.
21. Verma PK, Srivastava R, Gupta KK and Srivastava A.
BIBLIOGRAPHY Combined endodontic–Periodontal lesion: A clinical
dilemma. J. Interdis. Dent.: 2011; 1:119–124.
1. Bashutski JD and Wang HL. Periodontal and endodontic 22. vonArx T and Cochran DL. Rationale for the application of

34 regeneration. J. Endod.: 2009; 35:321–328.

2. Chapple I and Lumley P: The periodontal-endodontic
interface. Dent Update: 1999; 26:331.
the GTR principle using a barrier membrane in endodontic
surgery: a proposal of classification and literature review.
Int. J. Periodontics Restorative Dent.: 2001; 21:127–139.

t.me/Dr_Mouayyad_AlbtousH
 Chapter
35
Endodontic–
Orthodontic Continuum

Almost all professional specialties of dentistry are inter- IMPLICATIONS OF ORTHODONTIC TOOTH MOVEMENT
related. Endodontics is mainly interrelated to The force created by orthodontic tooth movement has
periodontics, orthodontics and restorative dentistry. definite effect on underlying tooth tissues. The clinical
The relation between orthodontics and endodontics implications are:
has attracted less attention of the researchers. There
might not be any definite guidelines on the subject, a. Effect of Orthodontic Tooth Movement on Pulp
which make the treatment planning and execution The magnitude of rapidity of orthodontic movement,
difficult for the clinicians. The orthodontic movement which may cause pulpal damage has not been properly
inevitably causes biological reactions in periodontal and documented. The pulpal degeneration may occur after
pulpal tissues. The clinician must be aware of the tipping forces or rapid tooth movement, owing to loss
possible complications and also the management of of collateral supply to the pulp. The ‘tipping force’
such complications during orthodontic movement of concept has been refuted, claiming successful rotation
teeth. of 72–108° without any pulpal damage. The ‘force’,
The combination of endodontics and orthodontics however, do affect pulpal vitality. The mechanisms
in majority of clinical situations present better which lead to changes in pulp vitality can be under-
results when treated both ways. The pulpal health, stood from the following factors:
during orthodontic movement is to be analyzed i. Respiratory rate of the pulpal cells
periodically; in case of any indication of disease process, ii. Blood flow to the pulp
the same should be managed properly. These two iii. Neural response of the pulp.
specialties are intertwined theoretically and clinically;
therefore, aptly referred to as ‘Endodontic–orthodontic i. Respiratory Rate of the Pulpal Cells
continuum’. Respiration is a sign of vitality for any living tissue.
Any change in the rate of respiration of any cell affects
Endodontic–orthodontic continuum is inseparable in
the state of its vitality. The pulp and its living compo-
the following situations:
nents are no exception to it. Orthodontic movement
• When orthodontic therapy warrants endodontic depresses the respiratory rate by a mean value of 27.4%.
intervention (post-treatment resorption and loss of A few authors have observed a significant correlation
vitality of orthodontically treated teeth). between amount of decrease in pulp tissue respiration
• When endodontic therapy warrants orthodontic rate and the age of the patient. This rate of respiratory
intervention [loss of clinical crown due to advanced depression is more in older patients due to the
caries/resorption near alveolar crest/periodontal constriction of their apical foramina that decreases the
blood flow. This also explains why younger teeth show
problems, requiring forced eruption (forced eruption
less effect than the older ones. The changes in tissue
is recommended in anterior teeth only)].
respiration (possibly hypoxia), because of orthodontic
• When orthodontics requires endodontic intervention movement of tooth, cause increase in aspartate
for better results (endodontic intervention to halt an aminotransferase (AST) activity level and affect pulp
ongoing resorption prior to starting of the orthodontic tissue, changing its neural response. It has also been
treatment). opined that decrease of some protein expressions block

597

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 598 Essentials of Endodontics

the regeneration of pulp structure. Radiorespirometric observed no significant change in teeth treated with
methods have confirmed respiratory depression in conservative orthodontic treatment. Calcitonin gene-
pulp, which is under orthodontic tooth movement. related peptide (CGP), a neuropeptide released from
C-type nerve fibers of pulp after injury, has the ability
ii. Blood Flow to the Pulp to initiate vasodilatation along with regulating inflamma-
It is hypothesized that dynamic mechanisms exist in tory cells (macrophages, mast cells and lymphocytes).
the control of blood flow in a tooth undergoing CGP has been shown to increase in teeth under ortho-
orthodontic movement. When an orthodontic force is dontic force as compared to normal neuropeptide values.
applied, pulp tissue reacts with initial pulp hyperemia, The decrease in the neural mediators causes a decreased
subsequently proceeding to degranulation of mast cells sensation of pain. The partial to complete diminution
characterized by cell damage and allied biochemical of the pulp space may be evident on radiographs. A
reactions. This is classical feature of acute inflammation. distinguishing feature is that such obliterations affect
The initial stage of reactive hyperemia usually reverts the apical third first followed by the coronal aspects of
back to normal in due course of time. When the pulp of the canal. Any case presenting with altered sensation
teeth subjected to orthodontic forces was grown in must be considered a manifestation of postorthodontic
culture, it showed sprouting of new vessels. Angiogenic pulpal damage. The healing in such cases is believed
changes have been observed after orthodontic to be normal. Orthodontic movement may not hinder
movement (increase in number of microvessels), periapical healing, but it certainly delays the process.
expressing rise of angiogenic growth factor in pulp. The
factors responsible for such changes are platelet derived Clinical Management
growth factor, vascular endothelial growth factor and • After orthodontic treatment: The resorption after
transforming growth factor-β. Transforming growth orthodontic treatment may cause an insufficiency of
factor β-1 (TGF-β1) and (TGF-β3) are responsible for the apical dentin matrix, which often leads to overfill.
stimulation of reactionary dentin and also reparative It is advocated to shorten the working length in such
dentin after orthodontic tooth movement. Since dental cases. The idea is to detect the most apical radio-dense
pulp is limited in narrow area, the increase blood flow point on the radiograph, which is usually 1.5–2.0 mm
(dilatation of arterioles) cause increase in pulp pressure short of the apical end.
and compression of venous flow. It is established that • During orthodontic treatment: Electrical pulp testing
most of the changes in pulpal blood are reversible may not be possible due to placement of orthodontic
(during tooth movement); only if pulp is not irritated bands. The electric pulp tester may also lead to
earlier because of deep caries, trauma, etc. It is also inaccurate readings because of edema and local
asserted that fully developed (mature apex) teeth are vascular damage. Also, the radiolucency due to
sensitive to irreversible pulp inflammation and orthodontic movement may often be confused with
immature apex teeth are not sensitive. It is established radiolucency of pulpal origin confounding the
that application of severe force for a longer period may diagnosis. Isolation is also difficult in such cases as
affect pulpal blood flow than short-term application of rubber dam placement becomes difficult. Calcifica-
same force (laser Doppler flowmetry evaluation). The tions, which may occur due to orthodontic treatment
two variables of decrease in pulpal respiration and an also make endodontic treatment challenging. In
altered blood flow interplay to bring about dystrophic anterior teeth, the lingual brackets may force the
mineralization with deposition of reparative dentin in endodontist to change the position of the access
coronal and radicular portions of the tooth. It is opening from the lingual to the incisal.
established that such changes beginning at the periapex
influence the odontoblasts in the formed teeth and b. Orthodontic Force and Root Resorption
Hertwig’s Epithelial Root Sheath (HERS) in the Root resorption due to application of orthodontic force
developing teeth. Such changes, especially when on teeth is not uncommon. Resorption is generally
accompanied with a history of previous trauma described to be of three types: Surface resorption
contribute to the mechanism of loss of pulp vitality after (occurring on cemental surfaces), inflammatory
orthodontic movement. resorption (resorption reaches infected dentin and an
inflammatory reaction follows) or replacement
iii. Neural Response of the Pulp resorption (where part of resorbed area is replaced by

35 Neural response during orthodontic tooth movement

has also been evaluated. A few authors examined pulp
axon response to orthodontic tooth movement and
bone causing ankylosis). Orthodontic forces cause
surface or inflammatory resorption and rarely the
replacement resorption. Apical resorption is four times

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 Endodontic–Orthodontic Continuum 599

effect on root resorption; whereas, morphology of roots

and sex were not associated factors. CBCT evaluation
also could not find any statistically significant difference
in root resorption between root-filled and vital teeth.
Cervical root resorption, a destructive form of
external resorption, characterized by osteoclastic cells
adjacent to dentin, was also evaluated as an effect of
orthodontic tooth movement. Authors were of view
that orthodontic treatment was the most frequent
a
predisposing factor in the development of cervical
resorption (trauma and intracoronal bleaching are the
other causes).
Routine periapical radiographs are generally effec-
tive in diagnosis of root resorption. CBCT, however,
enables more accurate view of root resorption than
traditional radiographs. CBCT provides even minute
details of resorption without any distortion. Axial
guided navigation, used to measure the axial length of
teeth (from cups/incisal tip to root apex), has also been
used to evaluate apical resorption.
b
Fig. 35.1 Root resorption in mandibular first molar after c. Orthodontic Tooth Movement
Orthodontic treatment: (a) Preoperative (encircle); (b) Root
and Periapical Lesions
canal treated (encircle)
It is established that orthodontic tooth movement does
more common than lateral resorption (Fig. 35.1a and b). not affect pathogenic and virulence of microbial biofilm
This may be attributed to the use of excessive forces and chronic inflammatory periapical lesions. The
especially in case of extreme proclination. The incidence orthodontic forces can be applied 2–4 weeks later after
is increased further in the presence of existing defects completion of endodontic treatment (exudate and
like blunt rooted teeth and invaginations. It is established inflammatory leakage is absorbed within 2–4 weeks).
that adults are more prone to resorption because In case of teeth with apical periodontitis, the
periodontal membrane becomes less vascularized and periapical environment is changed, having higher
inflexible leading to difficulty in tooth movement with bacterial concentration and inflammatory bony
aging. changes. The existence of these factors may complicate
healing process during orthodontic tooth movement.
Mechanism A few authors opined that orthodontic movement may
It is hypothesized that the pulp is responsible for delay the healing; however, did not prevent healing.
resorptive changes as an after-effect of orthodontic A few studies have evaluated the effect of ortho-
treatment. The sympathetic neurons of the pulp (both dontic tooth movement on teeth subjected to periapical
Aδ and C fibers) release intraaxonal compounds like endodontic surgery. It is suggested that more apical
substance P, calcitonin, gene related peptide, neuro- resorption may develop as dentin is exposed at the apex
kinin A, etc., which are neurogenic vasodilators that coupled with irritation of root-end filling material
increase the blood supply of the pulp. The increased (inflammation and leakage from the root end).
blood supply as caused by these mediators enhances
It has been established that persistence/partial
the availability of osteoclast precursors, which are
regression of periapical lesions as a result of endodontic
responsible for the resorption of roots.
treatment is independent from orthodontic movement.
Recently, specific genetic variables, IL-1β and 1L-1α
Orthodontic movement is not a cause for endodontic
have shown predisposition to root resorption, after
orthodontic tooth movement. Root resorption in root failures.
filled teeth is significantly related to various inter-
mediary genetic variations to inflammatory response. d. Endodontic Surgery and Orthodontic Forces
A few authors studied predisposed factors associated
with orthodontic tooth movement. They observed that
increased age and prolonged pressure had significant
The literature is deficient as regard orthodontic
behavior of teeth after endodontic surgery. A healing
period of three months to six months is recommended
35

t.me/Dr_Mouayyad_AlbtousH
 600 Essentials of Endodontics

before attempting any forces on an endodontically b. Endodontic Guidelines

treated tooth. Three months of healing period must The endodontic guidelines are:
be kept as a safety margin even for non-surgical cases • The endodontic therapy is initiated in the beginning.
with periapical radiolucency before attempting ortho- • During orthodontic movement, the canal is kept
dontics. clean and temporarily sealed.
• The obturation may be delayed till orthodontic phase
ORTHODONTIC EXTRUSION is over.
(FORCED ORTHODONTIC ERUPTION) (There is no contraindication to completion of
Certain clinical situations may warrant forced ortho- treatment, except that the operator is at ease if the
dontic eruption of the affected tooth, such as caries orthodontic appliances are not interfering).
causing loss of crown, resorption near alveolar crest, • In case the root is filled with silver points or even in
infrabony periodontal defects, etc. routine retreatment, the orthodontic extrusion is
Usually crown lengthening procedures utilizing recommended first, followed by removal of silver
periodontal surgery are followed to get access to tooth points/gutta-percha (retreatment will be convenient).
structure submerged under the gingival tissue. Ortho-
c. Orthodontic Guidelines
dontic extrusion in such situations offers advantages
as: The orthodontic guidelines are:
• No unnecessary bone cutting to maintain alveolar • Orthodontic movement should be initiated only in
crest morphology case of good periodontal health.
• Extrusion forces do not cause resorption (in fact they • Adequate anchorage must be considered (presence
cause deposition) of two teeth on each side of tooth to be extruded)
• Eliminates periodontal defects without periodontal (Fig. 35.2b).
surgery • Extrusion of anterior teeth is acceptable as it brings
the conical portion of the root near the cemento-
• Esthetically better than surgical intervention.
enamel junction of adjacent teeth. Thus, interdental
environment is improved if root proximity is
Guidelines
originally present (Fig. 35.2a).
The following guidelines must be kept in mind for the
health of periodontium and endodontium during
orthodontic extrusion.

a. Periodontal Guidelines
The periodontal guidelines are:
i. Biological width: The biological width (combined
width of the connective tissue and junctional
epithelium) should be taken care of during
orthodontic extrusion. The crest of alveolar bone
to cementoenamel junction is about 1.07 mm and
a
to junctional epithelial attachment is about
0.71–1.35 mm. Thus additional 1.0–2.0 mm of sound
tooth structure must be available coronal to the
epithelial attachment. Distance from the alveolar
crest to the coronal extent of remaining tooth
structure should be minimum of 3.5–4.0 mm.
ii. Health of periodontal tissues: Periodontal tissues
must be maintained in a state of health. The entire
periodontal apparatus moves alongside the tooth
being extruded. In periodontal disease, the forces
so exerted may cause deepening of the periodontal b

35 defect. Thus both, the biological width and the

integrity of the periodontal apparatus, should be
maintained.
Fig. 35.2 Orthodontic extrusion: (a) Fractured central incisor;
(b) Orthodontic extrusion (adequate anchorage from
adjacent teeth)

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 Endodontic–Orthodontic Continuum 601

• Extrusion of posterior teeth is not recommended as involved, then a root canal treatment is the only way
their access to forced extrusion is less and secondly, to achieve the treatment plan as originally intended. It
it brings the furcation close to the cementoenamel is an essential prerequisite for an orthodontic treatment
junction of the adjacent teeth. Thus, the chances of a that all teeth be disease-free and endodontics plays a
furcation exposure increase. The problems of root key role in achieving this requirement. Any tooth,
proximity also increase especially in case of disto- which is marred by resorption before orthodontic
buccal root of upper first molar and the mesiobuccal treatment (resorption will be accentuated by the
root of upper second molar. orthodontic forces), should be managed endodontically.
• Prefer conventional fixed appliances. Removable
appliances may offer greater anchorage, but are Orthodontic Behavior of
dependent on patient compliance and also do not Endodontically Treated Teeth
stabilize the tooth after extrusion. The entire orthodontic–endodontic continuum is based
• Problems like accelerated mesial drift and unfavor- on the interaction of the endodontically treated tooth
able tipping must be corrected first. with the force applied by appliances. It has been
• Adequate retention phase to prevent relapse (8–12 questioned whether the endodontically treated teeth
weeks with sign of apical bone fill). behave differently than those teeth, which have not
undergone any such treatment.
Clinical Protocol It is hypothesized that an endodontically treated
There is usually a time gap between the movement of tooth (the neuropeptide influence is minimal) exhibits
the tooth and the movement of the attachment apparatus less resorption as the factors causing resorption are
with it. The healthy attachment apparatus may move missing.
along with the tooth. Light force also reduces this gap A few authors are of view that even though the teeth
time and the movement is nearly simultaneous. In case show the same movement but more resorption occurs
of heavy force, the attachment apparatus does not get in endodontically treated teeth.
adequate time for a simultaneous movement and only It is established that endodontic treatment does not
the tooth structure gets exposed. influence tooth movement. However, a fresh endo-
Clinical protocol for forced extrusion depends upon dontically treated tooth in which the operator has
whether the clinical crown is intact or not. inadvertently irritated the periapical tissues (slight
overfill), can lead to complications. Such overfills can
i. Tooth Lacking a Clinical Crown (Only Root) cause focal ankylosis which makes orthodontic
An appropriate stainless steel wire with loop extension movement very difficult. It is recommended that such
is cemented in the postspace. Semipermanent cement teeth that need endodontic intervention during
is used as this does not dislodge on pulling but does orthodontic treatment phase should be prepared and
dislodge on rotation. The brackets are bonded to filled with calcium hydroxide initially and obturated
adjacent teeth. This is carried out as incisally as possible only after the orthodontic movement is complete.
to increase distance between arch wire and loop. The
arch wire must lie passively. Extrusion may take Fate of the Root Filling in Case of Resorption
4–6 weeks. After stabilization for 8–12 weeks, the root The literature is deficient on the fate of the root fillings,
is restored with appropriate post and core restoration. once resorption sets in. The root filling may exfoliate
ii. Tooth with Intact Crown Portion along with the tooth; otherwise, it may be left behind
in the bone after the tooth exfoliates and become
Place bracket as apical as possible on the tooth to be encapsulated. The apical seal may or may not be lost
extruded and rest of the bonding procedures are by resorption depending on the nature of condensation
followed as previously described. As the tooth of gutta-percha.
approaches during extrusion, a flexible wire deflected
2.0–3.0 mm is used, which gives an extrusive force. The
extruded tooth is stabilized for 8–12 weeks before BIBLIOGRAPHY
permanent restoration. 1. Abuabara A. Biomechanical aspects of external root
resorption in orthodontic therapy. Med. Oral Patol. Oral Cir.
Situations where Orthodontics Requires Bucal.: 2007; 12: E610–613.
Endodontic Intervention for Better Results
The orthodontists do not sacrifice a key tooth as a part
of the treatment plan. If such a tooth is pulpally
2. Alomari FA, Al-Habahbeh R and Alsakarna BK. Responses to
pulp sensibility tests during orthodontic therapy. Angle
Orthod.: 2009; 79:166–171.
35

t.me/Dr_Mouayyad_AlbtousH
 602 Essentials of Endodontics

3. Aydin H and Er K. The effect of orthodontic tooth movement 14. Ioannidou-Marathiotou I, Zafeiriadis AA and Papdopoulos
on endodontically treated teeth. J. Rest. Dent.: 2016; 4:31–41. MA. Root resorption of endodontically treated teeth following
4. Beck VJ, Stacknik S, Chandler NP and Farella M. Orthodontic orthodontic treatment: A meta-analysis. Clin. Oral Investig.:
tooth movement of traumatized or root-canal-treated teeth: 2013; 17:1733–1744.
A clinical review. Nz. Dent. J.: 2013; 109:6–11. 15. Javed F, Al-Kheraif AA, Romanos EB and Romanos GE.
5. Castro IO, Alencar AH, Valladares-Neto J and Estrela C. Influence of orthodontic forces on human dental pulp: A
Apical root resorption due to orthodontic treatment detected systematic review. Arch. Oral Biol.: 2015; 60:347–356.
by cone beam computed tomography. Angle Orthod.: 2013; 16. Lazzarett DN, Bortoluzzi GS, Torres Femandes LF, Rodriguez
83:196–203. R, Grehs RA and Martins Hartmann MS. Histologic evaluation
6. Cave SG, Freer TJ and Podlich HM. Pulp-test responses in of human pulp tissue after orthodontic intrusion. J. Endod.:
orthodontic patients. Aust. Orthod. J.: 2002; 18:27–34. 2014; 40:1537–1540.
7. Caviedes-Bucheli J, Munoz HR, Azuero-Holguin MM and 17. Popp TW, Artun J and Linge L. Pulpal response to orthodontic
Ulate E. Neuropeptides in dental pulp: The silent protagonists. tooth movement in adolescents: A radiographic study. Am. J.
J. Endod.: 2008; 34:773–788. Orthodont. Dentofacial Orthop: 1992; 101:228–233.
8. Deepa D, Mehta DS, Puri VK and Shetty S. Combined 18. Sameshima GT and Sinclair PM. Predicting and preventing
periodontic–orthodontic–endodontic interdisciplinary root resorption: Part I. Diagnostic factors. Am. J. Orthodont.
approach in the treatment of periodontally compromised Dentofacial Ortho.: 2001; 119:505–510.
tooth. J. Ind. Soc. Periodontol.: 2010; 14:139–143.
19. Santamaria M Jr., Milagres D, Iyomasa MM, Stuani MB and
9. Derringer KA and Linden RW. Vascular endothelial growth
Ruellas AC. Initial pulp changes during orthodontic
factor, fibroblast growth factor 2, platelet derived growth
movement: Histomorphological evaluation. Braz. Dent. J.:
factor and transforming growth factor and transforming growth
2007; 18:34–39.
factor beta released in human dental pulp following
orthodontic force. Arch. Oral Biol.: 2004; 49:631–641. 20. Veberiene R, Smailiene D, Baseviciene N, Toleikis A and
10. Durning P, Thomas M and McLaughlin W. Orthodontic Machiulskiene V. Change in dental pulp parameters in
extrusion: an interdisciplinary approach to patient response to different modes of orthodontic force application.
management. Dent. Update: 2009; 36:212. Angle Orthod.: 2010; 80:1018–1022.
11. Esteves T, Ramos AL, Pereira CM and Hidalgo MM. 21. von Bohl M, Ren Y, Fudalej PS and Kuijpers-Jagtman AM.
Orthodontic root resorption of endodontically treated teeth. Pulpal reactions to orthodontic force application in humans:
J. Endod.: 2007; 33:119–122. A systematic review. J. Endod.: 2012; 38:1463–1469.
12. Guevara MJ, McClugage SG and Clark JS. Response of the 22. Walker SL, Tieu LD and Flores-Mir C. Radiographic
pulpal microvascular system to intrusive orthodontic forces. comparison of the extent of orthodontically induced external
J. Dent. Res.: 1977; 56:243. apical root resorption in vital and root-filled teeth: A
13. Hamilton RS and Gutmann JL. Endodontic–orthodontic systematic review. Eur. J. Orthod.: 2013; 35:796–802.
relationships: A review of integrated treatment planning 23. Wang HL and Boyapati L. “PASS” principles for predictable
challenges. Int. Endod. J.: 1999; 32:343–360. bone regeneration. Implant Dent.: 2006; 15:8–17.

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 Chapter
36
Endodontic Failures
and Retreatment

Endodontics undoubtedly is the most progressive iii. Diseased: Radiolucency has emerged or persisted
branches of dentistry. The advancement in endodontic without change even when the clinical presentation
techniques and material has led to retaining significant is normal or clinical signs/symptoms are present
number of teeth in older adults. Root canal treatment even if the radiolucency is decreased.
is effective in preventing and healing apical perio- The patient’s perception of success is relief from acute
dontitis with varying success. It is established that symptoms, resolution of swelling or absence of pain
successful endodontics is based on the triad, i.e. correct and tenderness.
diagnosis, adequate cleaning and shaping and three- Basis of Failure
dimensional obturation. The proper execution of these
Failures can be classified as established failure and
steps facilitates healing of the periapical lesion with the
potential failure.
requisite osseous regeneration. Failure in root canal
a. Established failure: The failure is considered as
treatment is not uncommon. Root canal treatment
‘established’ when the patient and the operator are
usually fails when the standard protocol of ‘triad’ is
convinced of the clinical presentation, complaint and
not followed. Nevertheless, there are failures even after also the radiological assessment of the treated tooth.
following the highest technical standards. Scientific
b. Potential failure: The failure is considered as
evidences indicate that extraradicular and/or intra- ‘potential’ when one of the two (i.e. patient or the
radicular infections, and intrinsic and/or extrinsic non- operator) is not convinced of the clinical and radio-
microbial factors are responsible for failure. A number logical assessments of the treated tooth.
of factors are considered responsible for the unsatis- The clinical and radiological features of established
factory outcome of well-treated cases. Regardless of the and potential failures are tabulated in Table 36.1.
etiology, the main cause of failure is leakage and
bacterial contamination. In a rough estimate, the Causes of Failure
percentage of success in endodontically treated teeth The causes of endodontic failures are multifactorial;
ranges from 10 to 50% globally. broadly classified as follows:
1. Biological factors
Basis of Success a. Persistent intraradicular infection
The definition of success has always been ambiguous. The intraradicular infection may persist because of:
In endodontics, success implies clinical normalcy rein- (i) Poor aseptic environment; (ii) use of incorrect
forced with normal radiographic and histopathological irrigant/improper irrigation; (iii) inability to prepare
evidences. The percentage of success can vary if only till working length (Fig. 36.1a and b); (iv) missed
clinical parameter is considered; histopathological and canal(s)/hidden canal(s) (Fig. 36.2a and b); (v) proce-
radiological parameters should also be recognized. dural errors (Fig. 36.3a and b); (vi) poor obturation
The goal of endodontic therapy is to heal the disease (Fig. 36.4a and b); (vii) coronal leakage; poor coronal
process and also prevent its recurrence. The treatment filling (Fig. 36.5a and b); (viii) resistant micro-
outcomes in reference to healing are: organisms in the root canal intricacies
i. Healed: Both the clinical and radiographic presen- b. Persistent extraradicular infection
tations are normal. 2. Cystic lesions 3. Root fracture(s)
ii. Healing: Normal clinical presentation along with 4. Incorrect diagnosis 5. Foreign body reaction
reducing radiolucency. 6. Neuropathic problem.

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Table 36.1 Clinical and radiological features of failures

Types of failure Clinical features Radiological features
Potential failure • Sporadic or vague symptoms, usually not • No change in periapical radiolucency or slight
reproducible. evidence of healing.
• Feeling of pressure or tightness. • The periodontal ligament is not normal.
• Slight discomfort when chewing or pressing • Evident space between filling and root canal walls.
on tooth with finger or tongue. • Filling material/cement extending beyond the
• Overlapping symptoms of sinusitis in the anatomic apex.
region of the treated teeth.
• Occasional need of analgesics to alleviate
discomfort.
Established failure • Persistent symptoms. • The periapical radiolucency has not changed or has
• Recurrent sinus tract, swelling or pain. enlarged.
• Pain on percussion. • The appearance of new periapical or lateral radiolucency.
• Unable to chew with the tooth. • Absence of formation of new lamina dura.
• Pain during functional movements. • Evident space in the root canal that was not filled.
• Excessive overfilling.
• Evidence of progressive resorption.

a b a b
Fig. 36.1 Working length problem: (a) Short working length Fig. 36.2 Missed canals: (a) Missed canal in mandibular
in mesial canal; (b) Improper working length incisors; (b) Two root canals evident (arrows)

a b a b
Fig. 36.3 Procedural errors: (a) Perforation during root canal Fig. 36.4 Poor obturation: (a) Incomplete obturation (molar);
preparation; (b) Perforation during postspace preparation (b) Poor condensation (incisor)

36 a b
Fig. 36.5 Poor coronal restoration: (a) Leaky filling; (b) No coronal restoration since long

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 Endodontic Failures and Retreatment 605

NONSURGICAL RETREATMENT for retreatment is based on sound biological objectives

Retreatment in endodontics implies that procedures of elimination and future exclusion of microorganisms
carried out on teeth that demonstrate incomplete endo- from the root canal system, facilitating conducive
dontic treatment (showing signs of failure), to achieve environment for healing.
successful results. Since, the causes of failure are summed
Treatment Planning
up as leakage and bacterial contamination, the retreat-
ment procedures are aimed at correcting the leakage Patient’s thorough history, clinical examination along
and subsequently the bacterial contamination. with radiographs and other diagnostic tests should
In order to control infection and its source, the root be performed to rule out non-odontogenic etiology.
canals need to be reprepared and retreated. The process Inspection should always be carried out under dry
of renegotiating the canals can be carried out using condition, good illumination and magnification, which
either orthograde (nonsurgical retreatment) or a allows the clinician to identify significant conditions
retrograde (surgical retreatment) methods. In a few invisible to the naked eye, e.g. fracture, marginal
cases, any of these methods are not feasible and the leakage, etc. Dyes can also be a useful aid in diagnosing
tooth is considered for extraction. fracture lines, caries, marginal defects, etc.
Surgical retreatment is preferred in cases of failure of Percussion test evaluates the status of periodontal
nonsurgical methods, where root resection is indicated tissues of previously root canal treated teeth. The electric
or the removal of post warrants fracture of root. Mostly pulp testing is usually of lesser value in root canal
nonsurgical retreatment procedures are carried out to treated teeth. The positive result means that there may
overcome failures in root canal treatment. be remaining pulp tissue, but the negative result may
not be correct for absence of pulp tissues. Such teeth,
Indications especially, if restored with full crowns, pose difficulties
The indications of nonsurgical retreatment are: in evaluating status of pulp.
• Poorly sealed canals with a possibility to improve Intraoral periapical radiographs should be taken
upon the quality of the previous instrumentation and from various angulations; at least two radiographs, one
obturation. conventional and the other one at mesial/distal angula-
• Conventional root canal treatment failed; reasons tion. The proximal caries and periodontal bone height
conspicuous to the operator, where surgical interven- can be evaluated using bite-wing radiographs. The origin
tion not required. and path of sinus tract is traced by inserting a suitable
size gutta-percha point and getting a radiograph.
Contraindication On the basis of clinical and radiological examination,
The conditions, which contraindicate nonsurgical a failure case can be categorized as a ‘potential’ or
retreatment are: ‘established’ failure. For potential failure, the quality
• Canal walls prone to perforation on further prepara- of the restoration and root canal obturation should be
tion due to thinness. evaluated. If it is satisfactory, then it is better to wait
• Inability to débride the root canal system due to: and watch. If only coronal restoration looks compro-
– Failure in removal of post or broken instrument. mised, then it is better to restore the coronal restoration;
– Sclerotic root canal, which cannot be negotiated. however, when the obturation is compromised and
• Root fracture, especially vertical fractures. there is only a potential threat, one should wait and
• Non-cooperative patient. watch. When the failure is established, the access
opening, without adversely affecting the tooth
Objectives of Retreatment structure, should be carried out nonsurgically. In
The objectives of retreatment are the same as for the doubtful cases, resinifying therapy is the treatment of
primary treatment of infected root canal system; to choice; however, non-accessible cases are preferably
eliminate the substrate harboring microorganisms and retreated with surgical means.
hermetically sealing the space with biocompatible Patient’s consent is extremely important in planning
filling material. In retreatment cases, the operator may retreatment. Since, retreatment would involve a fair
face root canals obstructed by posts, insoluble filling amount of time and expenses, the patient should be
materials or separated instruments. Furthermore, during informed of the perceived prognosis and also other
options, including extraction, etc.
the previous treatment, a variety of procedural errors
such as canal blockage, ledging, apical transportation
and root perforation might have occurred. The rationale
The protocol for management of failure of root canal
treatment is depicted in Flowchart 36.1.
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 606 Essentials of Endodontics

Flowchart 36.1 Protocol for management of failure of root canal treatment

MANAGEMENT OF ENDODONTIC FAILURES tooth with definite restorative material after removing
The features leading to endodontic failures and methods the ‘hanging gutta-percha’ points from the coronal
of retreatment are as follows. chamber (Fig. 36.6a and b). When coronal leakage is
the cause of failure, only rerestoration and/or revision
1. Coronal Leakage of root canal treatment followed by coronal restoration
It has been established that poor coronal seal, even (Fig. 36.6c) is the treatment of choice. Rerestoration of
when the obturation is of good quality, affects the coronal filling should be avoided in chronic cases
success of root canal treatment. The compromised (where leakage continued for a sufficient long-time).
coronal seal allows oral microorganism to invade the
root canal system; subsequently, the failures. Both 2. Inadequate Root Canal Treatment
microorganisms and their endotoxins are capable to Once the retreatment is planned, the first step is to
penetrate the obturated root canal; endotoxins may identify the type of filling material present in the root
penetrate faster than microorganisms due to their canal(s) and also the anatomical variations. The method
smaller size. It has been hypothesized that ‘hanging used to remove the root canal filling will depend on
36 gutta-percha’ in the coronal aspect is one of the major
cause of coronal leakage. It is important to restore the
the type of material, the longevity of the treatment and
the existing coronal restoration.

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 Endodontic Failures and Retreatment 607

Fig. 36.6 Coronal leakage: (a) Hanging gutta-percha (diagrammatic); (b) Hanging gutta-percha (clinical); (c) Poor
coronal restoration

a. Gaining Access through the Coronal Restoration When the access is gained through the coronal
The coronal restorations, except for full crowns, is to restoration, care should be taken as the guidelines pro-
be removed completely before starting the reaccess vided by the natural tooth are missing. Diamond points
preparation. The coronal silver amalgam or cements, are usually preferred for access preparation in porcelain
crowns (PFM or all-porcelain), while carbide burs are
if not removed completely, can create problems in
used for composite, amalgam alloy and the cast metal
executing retreatment procedures (Fig. 36.7).
restorations. The size and shape of access opening
In case of well-fitting crown, which fulfills form, should be such that the endodontic instruments should
function and esthetics, the access can be gained through not scrape the cavity walls during instrumentation as
the crown (Fig. 36.8). it may shave off metal chips that might irreversibly
block the canals, particularly in mandibular teeth. Use
of copious irrigation during access preparation reduces
the chances of microfractures and blockage of canal
system by the remnants of these materials.
Advantages of retaining the restoration
The advantages of retaining the existing crown are
that the isolation becomes easy, esthetics is not
compromised and the occlusion is not disturbed.
Retaining crown is also cost-effective.
Disadvantage of retaining the restoration
The disadvantages of retaining the crown are that it
limits the visibility; subsequently, increasing the
chances of iatrogenic mishaps. The decreased visibility
Fig. 36.7 Removal of coronal filling also increases the chances of missing secondary caries,
fracture lines, hidden canals, etc.
b. Gaining Access after Removal of Crown/and
Bridges
The full veneer crowns usually make the retreatment
difficult. Several techniques and methods are available,
which facilitates easy and safe removal of such crowns.
The removal of coronal restoration is known as ‘coronal
disassembly’.
Advantages
• Coronal disassembly allows better access to the actual
axis of the tooth and the remaining coronal structure

Fig. 36.8 Gaining access through crown

allows excavation of recurrent/hidden caries.
• Minor cracks and missed/additional canals can be
negotiated easily.
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Removal of Crown and Bridges ii. Percussive instruments: These instruments apply
The restoration (crown and bridge or crown) is to be percussive forces to the restoration, either directly or
removed cautiously, not to fracture the teeth and/or indirectly, in order to break the luting cement.
the restoration. An effort is made to cement the same However, this is an unpleasant technique, which may
cause pain or fracture of crown and/or tooth. The
restoration after retreating the tooth. In case it is difficult
SybronEndo Crown Splitter assists in safe and easy
to remove the restoration in one-piece without any
crown removal. Kavo Coronaflex works by delivering
damage, it is wise to cut the restoration in two or three
a pneumatic force. Pneumatic crown remover can be
pieces and removed. The safe removal of the restoration used with parachute technique (Fig. 36.10). Parachute
is important. technique uses metallic wires placed through two or
Safe removal depends upon many factors; such as more embrasures of the bridge in order to create loops
the restorative material (porcelain crowns are difficult acting as a rest for a metal rod. They are excellent
to remove than metal ones; porcelain fracture easily, device for removing intact restorations. Examples are
especially at the margin), type of cement used during Peerless Crown-a-Matic (Peerless International); and
cementation (resin cement and glass-ionomer cements Coronaflex (Kavo, America).
pose problem than zinc oxide and zinc phosphate iii. Active instruments: Active instruments work by first
cement). Experience of operator also affects safe actively engaging the restoration to be dislodged and
removal of the crowns. then applying the dislodging force. For actively
A variety of removal devices are available depending engaging the restoration, these instruments need a
upon the principle on which they are based. Ultrasonics small window, prepared on the restoration, which
is useful to loosen the cement around the margins of a can later be restored. Examples are Metalift (Classic
crown. Undermining the crown and opening up the Practice Resources); Kline Crown Remover
margins allows placement of crown remover. (Brasseler); Higa bridge Remover (Higa Manu-
The routinely used devices are: facturing); and WamKey (Dentsply). For Metalift
crown removal system, a tiny hole is created on
i. Grasping instruments: The instruments facilitate
occlusal surface of crown. A self-tapping instrument
grasping of the restoration from two sides. The applica-
threads the metal on the occlusal surface, breaks the
tion of pressure on the handle increases the grip of cement layer and subsequently loosening and
instrument on the restoration. The pressure on the removing the restoration. WamKeys need a small cut
handle is adjusted so as not to damage the restora- in the buccal or lingual surface of the crown and the
tion and to avoid the slippage. These are coated crown is lifted using the appropriate keys (Fig. 36.11).
with carborundum powder to prevent slipping. The
instruments with rubber cup on the beaks are also
available. Examples are KY Pliers (GC America);
Wynman Crown Gripper (Miltex Instrument
Company); and Trident Crown placer remover
(Trident Dental Inc.) (Fig. 36.9).

Fig. 36.10 Parachute technique

36 Fig. 36.9 Crown remover (conventional) Fig. 36.11 WamKey system

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 Endodontic Failures and Retreatment 609

Removal of Post and Cores

The removal of post in an endodontically treated teeth
always present great difficulties because of risk of
fracture/perforation of the root, especially when the
remaining root dentin is less (Fig. 36.12a and b).
However, with the recent technical advances, these
sequelae have been minimized. The protocol of removal
differs with the type of post and the material (whether
metallic or fiber). The ultrasound and other mechanical
post-removing devices, such as Post puller, Gonon post
removal system, Masserann instrument, etc. have been
Fig. 36.13 Wrench for removing screw post
tried to achieve postremoval.
The factors which influence removal of posts are: ii. Removal of fractured post
• It is easier to remove tapering post than parallel. The post-fractured within the root canal pose difficulties
Similarly, passive post is easier to remove than active in removal.
post. After getting excess to the post, the cement lute
• The resins cement and glass-ionomer cement, being between the post and the root is to be broken. Ultrasonic
more retentive, pose difficulty in removal than zinc vibrations along with certain devices (sword post
phosphate cement and zinc oxide eugenol cement. puller, etc.) are used to loosen the post. Once the cement
• It is easier to remove post when post’s coronal end lute is separated, the post can be removed with the help
lies above the orifice of the root canal. of fine beaked forceps, e.g. Stieglitz forceps. When a
• Experience of the operator. post is broken deep inside the canal, the Masserann kit
i. Removal of screw post (Micro Mega) helps to remove post without damaging
the root dentin.
The screw post is removed using the wrench provided
in the kit by the manufacturer (Fig. 36.13). Core material The process of removal should be performed with
is carefully removed from around the coronal end of great care to avoid undesirable complications, such as
the post using a bur and ultrasonic tips. While removing root fracture, canal perforation and extrusion of objects
the core, care should be taken not to damage the beyond root apex.
protruding head of the post in the pulp chamber. iii. Removal of fiber posts
Generally, the vibration created during drilling of The fiber posts are bonded to root dentin with bonding
core coupled with use of ultrasonic is sufficient to loosen agents and are difficult to remove. It is hypothesized
the post. The ultrasonic tip is moved around the post that in failed cases, coronal microleakage may disrupt
in an anticlockwise direction to unscrew it. Ultrasonic the bond integrity facilitating removal of these posts.
vibrations need to be applied for sufficiently long-time Since fibers in fiber posts are tough materials and
to unscrew the post. pose difficulty in removing, it is advised to use new
removal drills. The fibers wear out the drills quickly
and are susceptible to get separated inside the canal.
Use of new removal drill is preferred in every case.
The sequence followed for removal of fiber posts is:
• The post is trimmed at the level of pulpal floor/canal
orifice.
• A pilot drill is used to make a hole in the center of
the post.
• The post is hollowed out by the successive drills
available in the removal kits.
• The cement is softened using softening agents.
• The ‘hollowed post’ is screwed out, moving the
appropriate peeso reamer/H-file, anticlockwise.
Fig. 36.12 Removal of post and core: (a) Removal of crown
without post do not create stress in root; (b) Removal of
crown with post creates stress (may lead to fracture of root)
• The canal should be reprepared and reobturated
before placing the new posts.
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 610 Essentials of Endodontics

iv. Removal of core • Hand instruments are easier to retrieve than rotary.
It is difficult to remove cast cores as compared to • Stainless steel instruments are easier to remove than
composite and amalgam cores. A diamond point/ Ni-Ti. Ni-Ti instruments may get straighten within
carbide bur can be used to remove core material. In a curvature in the root canal; posing difficulty in
certain cases, the core material is pushed 2.0 to retrieval.
3.0 mm into the root canals. In such cases, after It is emphasized that all separated instruments need
removing the coronal aspect of core material, an not be removed. The time and site of fracture are
ultrasonic tip is used across the pulp floor and the important. Time implies fracture of instrument prior
coronal part of the root, removing the material slowly to preparation, during preparation or after preparation
without risking perforation. of root canal. In case the instrument gets separated after
For cast post and core, attempt should be made the root canal preparation (during finishing stage), the
to remove the post and core in one entity. If not same is left in the root canal, filling the rest of the root
possible, the core is separated, removed first and then canal. The site implies fracture of instrument at coronal,
the post can be loosened with the help of ultrasonics. middle or apical areas (Fig. 36.14a to c). Instrument
The loosen post can be retrieved with the conventional fractured at apical area pose difficulties in removal;
gadgets. surgical interventions are only treatment of choice. In
such cases, by-passing the fragmented instrument and
Removal of Separated Instruments engaging the same with other obturating material is
The fracture of endodontic instruments (files, reamers, preferred treatment modality.
rotary instruments, pluggers, etc.) is quite common in
There are three phases for removal of separated
clinical practice. The causes of fracture are:
instruments.
• Improper handling
i. In case the separated instrument is below orifice
• Using instrument out of sequence
level, the coronal end of root canal is widened to
• Using excessive force, especially in rotary instrumen- get straight line access up to the coronal end of the
tation separated instrument. The non-cutting tungsten
• Spending excessive time in root canal carbide bur (Endo-Z) and diamond bur with non-
• Lack of failure of inspection of the instrument prior cutting tip (LA Axxess) can be used to achieve the
to use requisite straight line access (Fig. 36.15a to d).
• Iatrogenic causes. ii. Once the separated instrument is visible, the
Factors affecting instrument removal ultrasonic energy is applied to the lateral surface
of the fractured instrument to loosen the same.
The factors, which favor easy removal of separated
Ultrasonic energy is not applied at the coronal end.
instruments are:
If the energy is applied to the coronal end, the
• Straighter the root canal easier the removal. instrument may get embedded deeper into the root
• Retrieval from coronal portion is easier than middle canal. The ProUltra ENDO-3, 4, 5 ultrasonic tips
and apical portion of root canal. The separated instru- are utilized for this purpose. Additionally, they are
ment lying coronal to curvature is easier to remove coated with zirconium nitride to improve durability
than apical to curvature. and cutting efficiency. Zirconium nitride resists
• Longer fragments are easier to remove. corrosion, regardless of the irrigant employed, does

36 a b c

Fig. 36.14a to c Sites of separated instruments

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 Endodontic Failures and Retreatment 611

a b

c d

Fig. 36.15 Removal of separated instrument: (a) Preoperative (mandibular second premolar); (b) Separated instrument
engaged and removed; (c) Root canal obturated; (d) Postspace preparation

not flake-off during use, and provides safety during In case direct access is not feasible, by-passing the
intracanal procedures. The ENDO-6, 7 and 8 ultra- instrument is the treatment of choice. A drop of acid
sonic tips are made of titanium to provide clinicians etch is trickled in the root canal where the
with thinner diameters and longer lengths. These instrument was broken. After a couple of minutes,
instruments are utilized in deeper spaces where by-passing the broken instrument is tried using
access is more restrictive. small number file (Fig. 36.16). The residual acid etch

Fig. 36.16 By-passing the separated instrument (diagrammatic)

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t.me/Dr_Mouayyad_AlbtousH
 612 Essentials of Endodontics

is washed out. The canal is prepared in routine and separated file and lift it out. The disadvantage
obturated (Fig. 36.17a and b). Alternatively, a small of these systems is that they require excessive
round bur is cut into half and reached up to the removal of dentin for gaining direct access and
fractured site (Gary-Carr technique). It provides engaging the separated instrument. The available
appropriate dentin for by-passing the fractured systems are: Cancellier Extractor Kit, PRS System
instrument (Fig. 36.18). The canal is prepared in kit (Fig. 36.19a), Masserann kit, Spinal tap Needle,
routine and obturated. Endo extractor system (Fig. 36.19b), Meisinger
iii. Another instrument (system) for removal of separated Meitrac Instrument system, Instrument removal
instruments has disposable tube to capture the system, etc.

a b

Fig. 36.17a and b By-passing the fractured instrument (arrow)

Fig. 36.18 Gary-Kerr technique

36 a b

Fig. 36.19 Fractured instrument removal (kit): (a) PRS instrument removal system; (b) Endo extractor system

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 Endodontic Failures and Retreatment 613

Instrument Removal System (IRS) is a two- Hedstroem file is gently inserted extending
component system, designed to mechanically 1.0–2.0 mm beyond the apical end of the root canal.
engage separated instruments. Each microtube has The file is pulled gently retrieving the gutta-percha.
a small-sized plastic handle to enhance vision • When the gutta-percha is well-condensed, the
during placement, a side window to improve mechanical means [gates glidden drills (No. 2 or 3)]
mechanics, and a 45° beveled end to “scoop up” are used to remove gutta-percha from coronal part.
the coronal end of a broken instrument. Each screw A rotary file of smaller size than the root canal is
wedge has a knurled metal handle, a left handed used to remove gutta-percha apical to the coronal
screw mechanism, and a solid cylinder that area. Rotary files are also effective in generating heat,
becomes tapered towards its distal end to facilitate which further softens the gutta-percha. A heated
engaging an instrument. instrument or heated plugger can also be used. The
combination of solvent (xylene, eucalyptol, chloro-
Removal of Obturating Materials form, methyl chloroform, halothane or rectified
Various materials are being used, either alone or in turpentine) and hedstroem file can then be used to
combination, to obturate root canal. The complete remove the material from the remainder of the canals.
removal of these materials may pose challenge in In open apex cases, extra care must be taken to
retreatment cases. The commonly used obturating prevent the solvent or the softened gutta-percha from
materials and methods of their removal are: being forced out of apex. Chloroform is potential
carcinogenic and mutagenic; however, it is unlikely
i. Removal of gutta-percha
that chloroform in small quantity (normally less than
Gutta-percha has always been preferred as obturating 1.0 ml) required in the endodontic retreatment would
material. In retreatment cases, removal of gutta-percha be hazardous. Specific gutta-percha removal instru-
is comparatively easier than other obturating materials. ment, as the GPX is also available. The C+ file (a
The methods employed for removing gutta-percha stainless steel end-cutting hand file), with varying
may differ according to obturating technique used. taper is effective to cut through well-condensed
• The single cone gutta-percha can be removed easily gutta-percha.
as the space around the gutta-percha cone is filled In curved root canals, there are increased chances of
by the sealer. Similarly poorly condensed gutta- creating ledges, perforation and instrument fractures, etc.
percha can be removed easily. A gap is created with so extra care is exercised during removal of gutta-percha.
an explorer and a suitable Hedstroem file is screwed Improper removal of gutta-percha and/or post-space
into the space. A steady withdrawal force is exerted preparation may lead to perforation (Fig. 36.21a and b).
to remove the gutta-percha points. Gutta-percha is
engaged on sides with a Hedstroem file and moving ii. Removal of carrier based obturating devices
the file in pull-motion, gutta-percha is removed The carrier based obturating devices (e.g. Thermafil)
(Fig. 36.20). The endosonic file with irrigant can be usually consist of a metal or plastic carrier covered in
used to break sealer layer. Heated instrument alpha phase gutta-percha. The earlier Thermafil
(plugger, file, etc.) can also be used to remove gutta- obturator had metallic carrier, which was later replaced
percha in pieces. Alternatively gutta-percha solvents by plastic carrier, facilitating easy retreatment. Once
can also be used (gutta-percha solvents should be the carrier is exposed, the gutta-percha is removed
used along with endodontic instrument). The over- slowly using H-file along the sides of carrier. Solvent
extended gutta-percha points are difficult to retrieve
as the gutta-percha extruded from the apical
constriction tends to break from that point. A fine

36
a b

Fig. 36.21 Improper removal of gutta-percha: (a) Lateral

Fig. 36.20 Removal of gutta-percha with Hedstroem file perforation; (b) Labial perforation

t.me/Dr_Mouayyad_AlbtousH
 614 Essentials of Endodontics

can also be used along with H-file to facilitate softening iv. Removal of obturating pastes
and removal of gutta-percha. An appropriate file Various pastes are occasionally used as obturating
(usually 0.04 taper), depending upon the configuration material. Pastes normally have a soft consistency, but
of canal should be rotated in the groove of the carrier some materials can get hardened with time. The
and advanced with light pressure. Frictional heat allows bacterial activity after microleakage may result in
the instrument to advance apically and create a pilot sludge-like consistency of the pastes.
channel. When resistance is felt, switch to greater taper The majority of material is removed by rotary
(0.06 taper) file. Owing to the greater taper, the instruments, the remaining tags can be removed by
instrument will bind in the carrier, and the pulling force H-file/microdebrider along with endosonic irrigation.
can take it out. Thermafil, if remain in place for a long, The vibrating file loosens the paste, which is flushed
the gutta-percha usually become hard. Gutta-percha away by irrigant. Obturating pastes in the coronal and
solvents can be useful in such cases (Fig. 36.22). middle third are relatively easily removed; however,
iii. Removal of GuttaFlow removal in apical third is difficult.
GuttaFlow can be removed using similar techniques Certain cements may have radiopacity similar to
as used for removal of condensed gutta-percha. It is a that of dentin; hence, indistinguishable within the canal.
cold gutta-percha filling system that utilizes a silicone The commonly encountered cements are AH 26, zinc
matrix and shredded gutta-percha. The thermoplastic phosphate and glass-ionomer, etc. The cements can be
synthetic polymer (Resilon) when used as obturating soluble and insoluble. Soluble cements can be softened
material, can be softened with heat, or dissolved with by Endosolv E (for eugenol based cements) and
solvents. Epiphany is a dual-cured resin sealer that is Endosolv R (for resin based cements); whereas, insoluble
used with Resilon. It is claimed that it forms a cements are impervious to penetration by solvents.
monoblock with dentin. The removal is carried out by Long shank, fine sized carbide burs/diamond point can
mechanical means. effectively remove insoluble cements. Fine filing should
be carried out in slow motion, verifying the depth
and direction of penetration. Good illumination along
with use of magnification can allow the operator to
distinguish between cement and the root dentin and
can reduce the risk of perforation.
v. Removal of silver points
Silver points are no longer considered suitable for
obturating root canals; however, operator may
encounter previously obturated silver points for retreat-
ment. Silver points are relatively easier to remove; the
cement usually get dissolved by the time retreatment
is planned. Generally, the root canal is not circular in
cross-section but has an oval or fin-shaped morphology,
leaving a space between dentin and silver point, which
Fig. 36.22 Gutta-percha solvent eases its removal (Fig. 36.23a to c).

36
a b c
Fig. 36.23 Removal of silver points: (a) Maxillary molar restored with silver points; (b) Removal of silver points; (c) Tooth
retreated with gutta-percha

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 Endodontic Failures and Retreatment 615

The method of removing silver points varies as

follows:
• Removal of silver point extending in pulp chamber: The
silver points are easy to remove if they extend into
the pulp chamber. The coronal end is grasped by
either the Stieglitz forceps or narrow beaked artery
forceps. Prior to this, the core material is removed
using ultrasonic tips. Cement around the orifices of
the silver cones can be removed using an endosonic
tip. The point so loosen, can be gripped with Stieglitz
forceps and withdrawn.
• Removal of silver point lying in canal: If the silver point
lies in the straight portion of the root canal, the
Masserann fragment remover kit will be useful.
Removal of well-cemented silver points (newly
obturated) can be challenging. The cement is care-
fully removed from pulp chamber using ultrasonics.
An appropriate solvent is used to soften the cement.
If the root is too slender to permit the use of the Fig. 36.24 Locating missed canal under microscope
Masserann kit, attempts should be made to bypass
and remove the points with Hedstroem files. If iii. The access cavity is widened (diverging occlusally),
removal is not possible even after bypassing, the involving the roof of pulp chamber. The floor of
silver point should be incorporated with the new the pulp chamber is explored thoroughly with
filling. endodontic explorer for any catch, which may
• Removal of sectional silver point: The sectional silver indicate orifice of missed canal.
point, which is usually placed with a post, poses iv. Location of canal orifice can also be negotiated by
difficulty in removing. The root canal is enlarged the use of dyes, ultrasonic tips, sodium hypochlorite,
coronally. After dissolving the cement lining, by- etc. Dyes, such as methylene blue is applied on the
passing with H-files can be useful. Alternatively pulp chamber; upon rinsing and drying, the dye
periapical surgery can be planned to expose and leaves the stains in orifices and isthmus areas indicat-
remove the silver point from the apical end. ing missed canals. The color of the dentin around
the orifice is slightly darker than the surrounding
3. Missed Canals dentin, which can be a good indication. Presence
Missed canals have always been a source of failure in of pulpal remnants can cause bubbling with sodium
root canal treatment. Knowledge of possible deviations hypochlorite; if flooded pulp chamber shows
of root canal anatomy is mandatory for successful bubbling, it is also a good indicator for root canal
endodontics. In case of failure (persistent pain and orifice.
infection), the possibility of extra canal should be Once the orifice is located, the canal is negotiated
explored before retreating the already obturated canals. with smaller files along with lubricants. Root canal
preparation and obturation is carried out as in routine.
The features helpful in negotiating missed canals are:
i. Intraoral periapical radiographs taken at different 4. Canal Blockage
horizontal angulations are helpful in locating The dentinal mud is created during root canal
missed canals. CBCT, providing three-dimensional preparation; and if not properly irrigated may block
view, is certainly beneficial. the root canal. Usually, the apical portion of the canal
ii. Proper illumination and working under magnifica- is blocked; however, any portion of root canal can be
tion help visualize the internal anatomy of the blocked (Fig. 36.25a and b). The residual cement after
pulp chamber much better than the naked eyes post-placement may also create block (Fig. 36.26a and
(Fig. 36.24). Magnification can be achieved by b). The content of dentinal mud is frequently infected,
either loupes or surgical microscope. Surgical
microscope provides magnified field as well as
illumination.
thus may result in persistent disease. Blocks can be
detected on radiographs as a short root filling. While
managing blocks, the canal is widened using crown-
36

t.me/Dr_Mouayyad_AlbtousH
 616 Essentials of Endodontics

a b
Fig. 36.25 Canal blockage: (a) Blockage in distobuccal root
of maxillary first molar; (b) Blockage in maxillary premolar

a b
Fig. 36.27 Ledge: (a) Diagrammatic; (b) Radiographic
(obturation follows this ledge)

(No. 8 or 10), precurved at 1.0–2.0 mm from the tip is

inserted and rotated slowly to detect the original path
of canal beyond the ledge. The file tip is slowly scraped
along the internal wall of the canal curve slightly
a b coronal to the level of ledge. A lubricant enhances the
ability to place the file into the apical segment of the
Fig. 36.26 Canal blockage: (a) Blockage due to residual
canal. Once the file reaches the estimated working
cement (arrow)—diagrammatic; (b) Blockage due to
residual cement (arrow)—radiographic
length, a radiograph should be taken to verify its
position. The filing is carried out circumferentially as
down technique up to the level of block. Copious in routine. Once the ledge has been bypassed and the
irrigation is required to flush out the debris. The canal can be negotiated with a conventional file, a non-
blockage is negotiated with precurved #8 or #10 file end-cutting hand file with greater taper is tried to
inserted slowly to crossover the debris. The chelating smoothen the ledge area. The anticurvature filing will
agents are used to soften the obstruction and facilitate enable the clinician to blend the ledge into canal
the penetration of the file. Slowly, the file is pushed to preparation. Once the cleaning and shaping is
the entire length of the canal. Once the length is completed, the canal is obturated (Fig. 36.28a and b).
negotiated, the blocked area is prepared using In rare instances, surgical intervention becomes
appropriate files. Ultrasonics can also be helpful to necessary, if by passing the ledge is not feasible.
dislodge the blocked debris. 6. Canal Transportation
5. Ledges During root canal preparation, it is mandatory to
maintain the shape of canal. The root canal instruments,
The root canal instrumentation, if not properly gouged if not properly used, especially at the apical area may
along the curvatures, may lead to creating a ‘cut’ in
the dentin short of apical terminus; known as ‘ledge’
(Fig. 36.27a). It is usually created at the beginning of
curvature when root canal instrument is used without
precurving or using excessive amount of apical
pressure. The radiograph suggests presence of ledge,
when the apical extent of filling is not in the center of
canal but on the outer side of the curve (Fig. 36.27b).
The main problem with the ledge is that the instrument
invariably lands at the ledge, while the original canal

36 is not negotiated. As for management, non-end-cutting a b

files are used up to the ledge to widen the canal Fig. 36.28 Ledge: (a) Ledge in mesial canal of mandibular
(continuous irrigation is mandatory). Then a small file molar; (b) The retreated canals

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 Endodontic Failures and Retreatment 617

a b

Fig. 36.31 Canal transportation in maxillary second

premolar: (a) Preoperative; (b) Postoperative (treated with
Fig. 36.29 Apical transportation (diagrammatic) MTA)

lead to deviated apical terminus. Such deviation from • When the apical transportation is ‘severe’, the barrier
the actual terminus is referred to as ‘canal transporta- material may not be effective; surgery is the only
tion’ (Fig. 36.29). The degree of transportation can be treatment of choice in such cases.
minimal (less than 0.1 mm), moderate (0.1 mm) and
severe (more than 0.1 mm). At the same time, that area 7. Perforation(s)
does not provide resistance form to condense gutta- Perforation is the communication of root space with
percha. Reverse architecture often lead to vertically periodontal tissues. Perforation can occur during
overextended but actually underfilled canals. preparation of an access cavity (Fig. 36.32), cleaning and
The management of canal transportation varies shaping of the root canal system (Fig. 36.33) and post-
according to the degree of transportation. space preparation. The expansion of an inflammatory
• When the change in location of apical terminus is resorption defect may also lead to perforation.
‘minimal’ the reverse architecture can be merged with Perforation can be classified as:
the original path and obturated. Precaution should i. On the basis of size
be taken to avoid strip perforation or weakening of • Microperforation (less than 0.5 mm)
dentinal walls. • Macroperforation (more than 0.5 mm)
• When the apical transportation is ‘moderate’ then it ii. On the basis of crestal level
becomes difficult to correct the reverse architecture • Supracrestal
without weakening the residual apical dentin. Such • Crestal
cases need a barrier material, which provides • Subcrestal
hemostasis as well as a platform to condense gutta- iii. On the basis of location
percha. The commonly used barrier material, MTA • Coronal (at the pulpal floor)
(Fig. 36.30), sets within 4–6 hours and form • Radicular (may be cervical, middle or apical).
cementum like barrier over it, thus allowing for a
normal periodontal attachment (Fig. 36.31a and b).

Fig. 36.30 MTA material

Fig. 36.32 Perforation during Fig. 36.33 Perforation during
access cavity preparation cleaning and shaping of
root canal
36

t.me/Dr_Mouayyad_AlbtousH
 618 Essentials of Endodontics

The prognosis of management of perforation mineral trioxide aggregate and biodegradable

depends on its location, size and time elapsed since its ceramics. The advantages of using MTA are, it seals
occurrence. The perforation should preferably be sealed well even when the space is contaminated with
as soon as possible, since the delay leads to micro- blood and is highly biocompatible. The disadvan-
leakage, infection and bone resorption. The radiographs tages are; it cannot be used for transgingival defects,
taken at mesial/distal angulation are important in as it requires long-time for setting; and direct
determining where a perforation exists and locating contact with oral fluids may wash out the material.
which surface(s) of the root have been perforated. Fast setting repair material (e.g. Geristore) is
Sometimes, the perforated area (usually very small) preferred in transgingival defects.
heals with time; evidences of healing in perforation After control of bleeding and before placement of
need no treatment. However, in case perforation has repair material, the root canals should be blocked
led to inflammatory changes, surgical/nonsurgical with paper point or cotton, etc. so that the repair
treatment is initiated depending upon the size and site material should not enter the canal orifices.
of perforation. iii. The furcation perforations are generally round;
Advantages of nonsurgical approach whereas, the lateral perforations are ovoid. The
• Less destruction of periodontium in comparison to defect needs to be disinfected after isolation and
surgical approach prepared before receiving the restorative material.
Ultrasonic instruments are employed to reshape the
• Less chances of secondary infections.
perforation site, if required. An appropriate barrier
Disadvantages of nonsurgical approach material and restorative material are selected; and
• May be time consuming the restoration is completed (Fig. 36.35a and b).
• Prognosis remains doubtful. iv. The middle third area is usually perforated by
misusing gates-glidden drills or misdirected post-
Procedure preparations. For management, hemostasis and
i. Microperforation when located coronally (pulpal disinfection followed by restoration are carried out
floor) can be sealed using light cure composite or as for furcation perforations. In these cases, the
glass-ionomers. The site is disinfected before sealing defect lies deeper and further away from occlusal
(Fig. 36.34a to c). surface. To prevent obstructing the root canal space
ii. Macroperforations, particularly if associated with during repair procedure, any readily retrieval
osseous defect, need a barrier or matrix, which material is placed in the canal as space holders
serves as a hemostat. Hemostasis is achieved using apical to the defect.
collagen or calcium sulfate. Astringents, such as In case the perforation is in the middle third of the
ferric sulfate, should be avoided because the root and sufficient access is available through the
coagulum they leave, may promote bacterial pulp chamber, the perforation can be repaired
growth, subsequently compromising the seal. The nonsurgically. The perforation site is cleaned and
barrier materials can be absorbable or non- refined by Endo 4 ultrasonic tip to ensure an
absorbable. The absorbable are collagen materials environment free of microbial contamination and
and calcium sulfate. The non-absorbable are necrotic tissue.

36
a b c

Fig. 36.34 Coronal perforation: (a) Cervical perforation of maxillary first premolar; (b) Perforation site filled and canals
retreated; (c) Postoperative (radiograph)

t.me/Dr_Mouayyad_AlbtousH
 Endodontic Failures and Retreatment 619

a b

Fig. 36.35 Furcation perforation: (a) Preoperative (mandibular first molar); arrow showing perforation; (b) Postoperative
(treated with MTA; arrow showing pushed out MTA)

A sterile, resorbable, and biocompatible collagen 3. Alhadainy HA and Abdalla AI. Artificial floor technique used
material is placed along the perforation site, to for the repair of furcation perforations: a microleakage study.
control hemostasis and prevent overfills; the J. Endod.: 1998; 24:33–35.
material also acts as an internal matrix. 4. Aqrabawi J. Management of endodontic failures: case selection
and treatment modalities. Gen. Dent.: 2005; 53:63–65.
The Mineral Trioxide Aggregate forms a colloidal
5. Aydemir S, Helvacioglu-Yigit D, Sinanoglu A and Emre O.
gel upon hydration, which solidifies in approxi- Retreatment of a maxillary lateral incisor with two separate
mately four hours. Therefore, when used as a root root canals confirmed with cone beam computed
repair material, moisture must be provided from tomography. J. Clin. Med. Res.: 2015; 7:560–563.
the internal aspect of the root. The Mineral Trioxide 6. Barrieshi-Nushair KM. Gutta-percha retreatment: effectiveness
Aggregate, because of its biocompatibility, is of nickel-titanium rotary instruments versus stainless steel
preferred as a material of choice to seal perforations. hand files. J. Endod.: 2002; 28:454–456.
The location of the perforation is an important 7. Bindal D. Endodontic non-surgical retreatment techniques –
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Oral Pathol., Oral Radiol. Endod.: 2008; 106: e67–69.
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9. Cavenago BC, Ordinola-Zapata R and Duarte MA. Efficacy
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13. Escoda-Francoli J, Canalda-Sahli C, Soler A, Figueiredo R and
should be carried out, if need be.
Gay-Escoda C. Inferior alveolar nerve damage because of
over-extended endodontic material: A problem of sealer
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36

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 Chapter
37
Resinifying Therapy
in Endodontics

The root canal treatment is becoming popular day by Indications

day. The world-wide dental surgeons are encouraged • Necrosis of pulp
to provide better endodontic services by simplifying • Larger rarefied area at periapex
procedure, shortening the appointment times and • Pulp exposure requiring pulp capping/pulpotomy
maintaining original teeth in the arch. Different ways
• Broken instruments/obstructions in the canal
and means have been tried to save the teeth so as to
• Lateral/accessory canal(s), which may cause
maintain the stomatognathic system.
problems during root canal procedures
In certain cases, teeth with pulp involvement do not • Vital dentin surface, as coating/temporization.
response to conventional root canal treatment. The
reasons are multifactorial; however, complications pose Contraindications
difficulties in executing the treatment, so the success • Immature teeth with open apices
rate is compromised. Such cases and in other conditions
• Anterior teeth (resin may stain the teeth)
where permanent treatment is to be delayed, resinifying
• Maxillary last molars are difficult; however, not
therapy is the best choice.
contraindicated.
Wang Manen (1957) initially suggested this treatment
modality. In this therapy, the liquid phenol-aldehyde Advantages
resin when inserted into root canal or poured over the • No need to remove the entire pulp
tooth surface, becomes solid after polymerization. The • Can be used as antimicrobial sealer
microorganisms and associated debris get resinified.
• No need for compaction or additional sealer
The resinifying agent has the potential to creep into
• Effective in retreatment cases, especially where the
tubules and set there, facilitating three-dimensional
access is difficult.
obturation of the root canal system. Even if the solution
is pushed beyond the apex, it does not cause any major Disadvantages
damage. After initial irritation, the healing progresses
(the irritation and the healing has been documented in • Not radiopaque
histopathological studies). • Delay in healing if leaks into periapical areas
• Staining of the treated teeth (reddish hue)
Sensitivity of resin resorcinol has been evaluated
The differences between resinifying therapy and the
against eight commonly found microorganisms in the
conventional root canal treatment are summarized in
root canals, viz. Enterococcus faecalis, Streptococcus
Table 37.1.
haemolyticus, Streptococcus salivarius, Streptococcus mitis,
Staphylococcus aureus, Escherichia coli, Lactobacilli and
Actinomyces. Zone of inhibition was observed both in Composition
Staphylococcus aureus and Streptococci haemolyticus, Resinifying agent consists of three solutions (Fig. 37.1).
indicating that the resin has definite antibacterial effect The composition of these solutions is as follows:
both before and after polymerization. Solution I
Tsao (1984) recommended resinifying therapy of Formaldehyde (38.48%) 62.0 ml
posterior teeth with larger periapical rarefied areas Cresol 12.0 ml
because of its simplicity and higher success rate. Alcohol (95%) 6.0 ml

621

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 622 Essentials of Endodontics

Table 37.1 Differences between resinifying therapy and conventional root canal therapy
Procedure Conventional root canal therapy Resinifying therapy
Removal of pulp Entirely removed Not necessary
Preparation of canal Mechanically enlarged No need (many studies have shown better results
with prepared root canals)
Disinfection of canal Removal of infected dentinal wall, application No need
of medication, sealing, etc.
Use of sealer Require appropriate sealer No need
Root canal obturation Require obturating material; gutta-percha, etc. Resin sets in the canal and acts as obturator

Solution II solution is stirred prior to use. Solution III is a catalyst.

Resorcin 45.0 gm The usual setting time of the mixed solution is four to
Distilled water 55.0 ml five minute. In case, the operator requires early setting
time, an extra drop of solution III can be added.
Solution III
Sodium hydroxide 1.0 gm
Distilled water 2.0 ml UTILITY OF RESINIFYING THERAPY
The three solutions are mixed in a clean dappen Resinifying therapy can be used in variety of cases. The
dish/container (Fig. 37.2) in the ratio of 5 : 5 : 2. The main are:

a. Resinifying agent as an Obturating Material

Isolate the selected tooth and open the root canals
following standardized technique. In case of vital pulps,
pulp residues in the apical end need not be removed.
In necrotic pulps, root canals may not be prepared
mechanically; however, a few authors recommend
preparing the root canal with conventional methods,
along with irrigation and dressing.

Procedure
Once the canal is ready for obturation, resinifying agent
is introduced into the root canals. A small drop of
Fig. 37.1 Solutions used in resinifying therapy resinifying agent is trickled over the coronal end of root
canal. A small file is used with up-down motion to
remove air and facilitate entry of the resinifying agent
into the root canal(s). This process is repeated till the
canal is filled. Leave the excess agent in the pulp
chamber. Allow the liquid resin resorcinol solution to
set in room environment (usual time of setting is
5–7 minutes). The coronal chamber is filled with interim
restorative material.
The clinical and radiological observations strongly
suggest that the resinifying agent has the capability to
infiltrate into the root canals including the accessory
canals. The resinifying agent has the potential to imbibe
into the dentinal tubules up to 1/3rd or 1/4th of the
total length (Fig. 37.3a and b). The residual pulp tissues
and the irritants get resinified and retained in the canal
without irritation to periapical areas. The root canals

37 Fig. 37.2 Mixing of three solutions in the ratio of 5 : 5 : 2

are obturated three dimensionally and the sealing of
canals is maintained for a longer period. The clinical
cases are exhibited in Figs 37.4a to d and 37.5a to d.

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 Resinifying Therapy in Endodontics 623

a b

Fig. 37.3 Penetration of resinifying agent into dentinal tubules: (a) Low magnification; (b) High magnification

a b

c d

Fig. 37.4 Mandibular second premolar treated with resinifying therapy: (a) Preoperative (large rarefied area at periapex);
(b) Tooth obturated with resinifying agent; (c) Postoperative (signs of healing at six month follow-up); (d) Postoperative
(complete healing at one year follow-up)
37

t.me/Dr_Mouayyad_AlbtousH
 624 Essentials of Endodontics

a b

c d

Fig. 37.5 Mandibular first molar treated with resinifying therapy: (a) Preoperative (large rarefied area around mesial root);
(b) Tooth treated with resinifying therapy; (c) Postoperative (signs of healing at six month follow-up); (d) Postoperative
(complete healing after one year follow-up)

b. Resinifying Agent as a Direct Pulp Capping Material and let it set. The rest of the cavity is filled with Kalzinol,
Direct pulp capping, though not so popular these days, zinc phosphate cement or any other restorative
is a treatment modality, whereby the exposed pulp is material.
covered by a suitable material to retain pulp vitality. The effectiveness of resinifying agent as pulp capping
Direct pulp capping has always been controversial. material has been histologically proved.
Materials that have been tried as pulp capping agents Histological sections revealed areas of fibrosis and
range from pulp caps to tricalcium phosphate ceramics; hyalinization in the pulp in the coronal area; however,
the accepted one is calcium hydroxide. Earlier in the middle and apical third of the sections, normal
hypothesis that calcium of calcium hydroxide forms the pulpal tissue was evident.
dentin bridge has been disproved. The antibacterial The fibroblastic activities present at the coronal sites
environment created by calcium hydroxide, may are suggestive of the healing process. The normal pulp
however, be responsible for healing. The exposure site, tissue, without any sign of necrosis, present in the
if left bacteria free, may heal without any medicament. middle and apical part of the root confirms that the
Resinifying agent has been successfully tried as direct resinifying agent can successfully be used in direct pulp
pulp capping material (Fig. 37.6a and b). capping.

Procedure c. Resinifying Agent as a Sealer

The exposure site is washed immediately with normal Resinifying agent has been tried as a sealer along with
saline solution and isolated with sterilized cotton rolls. routinely used obturating materials. This sealer is

37 The exposure site and the rest of the cavity is wiped

with cresophene. Two drops of freshly prepared
resinifying solution is poured over the exposure site
antibacterial, but may shrink and leave a reddish hue
on the outer tooth structure (hence the nickname
‘Russian Red’).

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 Resinifying Therapy in Endodontics 625

a b

Fig. 37.6 Resinifying agent as direct pulp capping material: (a) Traumatic pulp exposure in mandibular first molar;
(b) Application of resinifying agent at the exposure site

Procedure prepared resinifying agent is applied to the tooth

When used as a sealer, once the resinifying agent is surface with the help of a camel brush. It will set within
introduced to the root canals, single cone gutta-percha five minutes and form a resin coat over the tooth
is pushed up to predetermined working length before surface. The solution in the ratio of 5 : 5 : 3 can be used
the sealer sets. Once set, the excess gutta-percha is for fast setting (Fig. 37.8a and b).
removed and the pulp chamber is filled with suitable
materials (Fig. 37.7a and b). e. Resinifying Agent in Complications
Resinifying agent has been used in complicated areas.
d. Resinifying Agent as a Material for Temporization Because of its liquid form, it can penetrate into
Tooth preparation for full/partial veneer crowns needs inaccessible areas. It can be used in cases of:
immediate converge, especially in vital teeth. The • Broken instruments (Fig 37.9a to c)
laboratory procedures may take time, which may lead • Obstructions/old filling materials in the canal, which
to hypersensitivity. are difficult to remove (Fig. 37.10)
Procedure • Ledges, where the root canal is not negotiated
Resinifying agent can be used to cover the prepared beyond ledge
tooth prior to permanent restoration. The freshly • Teeth not responding to routine endodontic therapy.

a b

Fig. 37.7 Use of resinifying agent as sealer: (a) Preoperative (mandibular first molar); (b) Postoperative (signs of healing)
37

t.me/Dr_Mouayyad_AlbtousH
 626 Essentials of Endodontics

a b

Fig. 37.8 Resinifying agent as interim restoration: (a) Crown preparation; (b) Application of resinifying agent

a b c

Fig. 37.9 Resinifying therapy in managing separated instruments: (a) Preoperative (broken instrument in maxillary central
incisor); (b) Broken instrument by-passed (arrow) and treated with resinifying agent; (c) Postoperative (follow-up at
six months; signs of healing)

BIBLIOGRAPHY
1. Gound TG, Marx D and Schwandt NA. Incidence of flare-
ups and evaluation of quality after retreatment of resorcinol-
formaldehyde resin (“Russian Red Cement”) endodontic
therapy. J. Endod.: 2003; 29:624–626.
2. Lin KC and Kirk EEJ. Direct pulp capping: A review. Endod.
and Dental Traumatol: 1987; 3:213–219.
3. Matthews JD. Pink teeth resulting from Russian endodontic
therapy. JADA: 2000; 131:1598–1599.
4. Orstavik D. Materials used for toot canal obturation: technical,
biological and clinical testing. Endodontic Topics: 2005;12:25–38.
5. Sikri V, Manjri M and Sikri P. Direct pulp capping with
resorcinol: A clinical, radiological and histological evaluation.
JCD: 1998; 1:90.
6. Sikri VK and Sikri P. Resinifying Therapy in Endodontics: A
clinical and radiological evaluation. IJDR: 1995; 6:35–39.
7. Sikri VK, Sikri P, Singh J, Manjri M and Khanna S. Resinifying
Therapy in Endodontics II. Histological and bacteriological
evaluation. IJDR: 1996; 7:51–56.
8. Schwandt NW and Gound TG. Resorcinol-formaldehyde resin
“Russian Red” endodontic therapy. J. Endod.: 2003; 29:435–437.
9. Tsao TF. Endodontic treatment in China. Int. Endod. J.: 1984;

37 Fig. 37.10 Unretrievable gutta-percha treated with

resinifying therapy
17:163–175.
10. Wu Min-K. Clinical and experimental observations on Resinifying
Therapy. O. Surg., O. Med., O. Path.: 1986; 62:441–448.

t.me/Dr_Mouayyad_AlbtousH
 Chapter
38
Regenerative
Endodontics

Regenerative endodontics is concerned with the helps to gain greater knowledge of tissue engineering
development of biologically based treatment modalities involving interactions at cellular and molecular levels.
that are used to replace diseased portion of the dental The purpose of pulp treatment (maintaining the
pulp or to allow complete formation of a dental pulp- vitality of teeth damaged due to caries or trauma) is to
like tissue that will act as the original dental pulp. A maintain the tooth structure in order to preserve
form of regenerative endodontics began many years optimal function. Maintaining the pulp vitality is
ago with the development of direct and indirect pulp essential for continuous root development and apical
capping procedures. The need for scaffold, vascular closure, especially in case of immature permanent teeth.
supply, growth factors, signaling mechanisms, If the pulp of immature permanent teeth is infected,
migration concept of cells differentiation are accepted traditional approach ‘apexification’ is followed, which
regenerative procedures. Regenerative endodontic includes removal of infected pulp and application of
Procedures are defined as ‘biologically based procedures calcium hydroxide, MTA, etc. This treatment modality
designed to replace damaged tissues, including dentin, aids in closing the apical foramen; however, cannot
cementum and cells of the pulp-dentin complex as well’. maintain pulp vitality.
These procedures are also named ‘revascularization’, As the concept of regeneration endodontics is not
‘revitalization’, and ‘regenerative endodontics’. An under- new, various authors have tried regenerative treatment
standing of the processes and mechanisms to restore a procedures with varying results. The important studies
vital, healthy tissue within a tooth is mandatory, which are tabulated below.

Author (Year) Procedure

Hermann (1952) First to carry out regenerative endodontic procedure; applied calcium hydroxide in vital pulp
amputation.
Nygaard-Ostby (1961) Established a blood clot to use as a scaffold to revascularize tissue within root canals of
teeth.
Rule (1966) Introduction of polyantibiotic paste; no bleeding in the canals was evoked; instrumentation
short of what appeared to be the vital tissue.
Nygaard-Ostby (1971) Use of antibiotics in the disinfection protocol and the intentional promotion of intracanal
bleeding.
Hoshino (1993) Use of triple antibiotic paste.
Iwaya and colleagues (2001) Showed the revascularization potential of an immature permanent tooth without instrumentation
and with the use of an antibiotic paste composed of ciprofloxacin and metronidazole (double
antibiotic paste).
Banchs and Trope (2004) Case reports on immature mandibular premolars (new protocol followed).
ADA (2011) Adopted a new procedure code to allow clinicians to induce apical bleeding into the root
canal in immature permanent teeth with necrotic pulps that have been extirpated.

627

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 628 Essentials of Endodontics

Common Terms used in Regenerative Endodontics Apexogenesis: A vital pulp therapy procedure per-
Biomimetics: The science of reconstructing or mimicking formed to encourage continued development of root
natural process or tissue with the expectation that and physiological formation of its apical end.
regeneration will follow. Apexification: A method to induce a calcific barrier in
Gene: Specific sequences of nucleotides along a root canal with an open apex; or continued develop-
molecule of DNA (or RNA in the case of some viruses) ment of root in teeth with necrotic pulp.
that represent the functional units of heredity. Revascularization: The methods involve in restoring
Genetic engineering: Also called genetic modification, vascularity of a tissue or organ.
is the alteration of genetic make-up of an organism Guided tissue regeneration: Induced/guided regenera-
using techniques that introduce heritable material tion of the tissues.
prepared outside the organism, either directly into the
host or into the cell, that is then fused and hybridized Objectives of Regenerative Endodontic Treatment
with the host.
The objective of regenerative treatment is to regenerate
Gene therapy: The technique for the correction of a fully functional pulp-dentin complex to aid in
defective genes that are responsible for the develop- continued root development for immature teeth.
ment of disease by the insertion, alteration or removal The goals of regenerative endodontic procedures are
of genes within an individual’s cells and biological categorized as primary, secondary and tertiary;
tissues to treat disease. however, success of the treatment is confirmed by
Morphogens: They are extracellular secreted signals histological means. Histologic confirmation of dental
governing morphogenesis during epithelial- pulp with an intact odontoblastic layer and restoration
mesenchymal interactions. It is a biologic factor that of a functional pulp is undoubtedly the prime goal.
regulates stem cells to form desirable cell type. • Primary goal: Elimination of symptoms along with
evidence of bony healing.
Repair: It is the restoration of tissue continuity without
mimicking its original architecture or function. • Secondary goal: (Desirable, may not be essential);
increased root wall thickness and/or increased root
Regenerative medicine: The engineering and growth of length.
functional biological substitutes in vitro and/or the • Tertiary goal: (If achieved, indicates a high level of
stimulus to the regeneration and remodeling of tissues success); positive response to vitality testing.
in vivo for the purpose of repairing, replacing,
maintaining or enhancing tissue and organ functions.
TISSUE ENGINEERING
Regeneration: The restoration or new growth of organs,
The application of the principles and methods of
tissues, etc. that have been lost, removed or injured in
engineering and life sciences for the understanding of
an organism.
structure-function relationships in normal and patho-
Scaffold: It provides a physiochemical and biological logical mammalian tissues; and the development of
three-dimensional micro-environment for cell growth biological substitutes that restore, maintain, and/or
and differentiation, promoting cell adhesions and improve tissue functions.
migration. The scaffold serves as a carrier for morpho- Tissue engineering is defined as ‘an interdisciplinary
gens in protein therapy and for cells in cell therapy. field that integrates the principles of biology and engineering
Stem cell: A cell that has the ability to continuously to develop biological substitutes that replace/regenerate
divide and produce progeny cells that differentiate into human cells, tissues or organs in order to restore the normal
various other types of cells or tissues. function’.
Regenerative procedures and tissue engineering hold
Stem cell plasticity: It refers to the phenomenon of the promise of a solution to a number of clinical
generation of specialized cells of another generation by problems in dentistry. The endodontists can adopt these
the adult stem cells of one generation. scientific advances emerging from regenerative thereby
Stem cell therapy: A technology in which persons own developing regenerative endodontic procedures,

38 cells are triggered to revert to their primitive organic subsequently improving patient care.
form, which then redifferentiate into mature cells of The ultimate goal of tissue engineering vis-à-vis
various organs. regenerative endodontics is to develop therapies to

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 Regenerative Endodontics 629

restore lost, damaged or aging tissues using engineered the same way, the stem cells can become many tissues
or regenerated procedures derived from either donor by making certain changes in their environment.”
or autologous cells. William Sedgwick (1866) described certain cells for
The tissue of interest in regenerative endodontics the regenerative properties of plants, the ‘stem cells.’
includes dentin, pulp, cementum and periodontal Stem cells are unprogrammed cells in the human body
tissues. Tissue engineering implies clinical approach for that can be described as ‘shape shifters’.
feeding more or less biodegradable scaffold with donor Stem cells differ from other kinds of cells in the body.
cells/growth factors, then culturing and implanting the All stem cells regardless of their source have three
scaffold to induce and direct the growth of new healthy general properties:
tissues.
i. Capable of dividing and renewing themselves for
Triad of tissue engineering long periods
The key elements of tissue engineering are stem cells, ii. Unspecialized
growth factors (morphogens) and an extracellular iii. May give rise to specialized cell types
matrix scaffold; known as ‘Triad of tissue engineering’
Isolation of stem cells involves enzymatic digestion of
(Fig. 38.1).
tissues followed by growth of isolated cells in a medium
a. Stem cells rich in growth factors. The differentiation of these cells
b. Growth factors involve: (i) Colony forming assays, (ii) Phenotypic
c. Scaffolds. assays and (iii) Flow cytometry.
These cells are stored in liquid nitrogen at –196°C
a. Stem Cells (preservation in a liquid phase).
Stem cells are unspecialized cells in the human body
that are capable of becoming specialized cells, each with Culturing of Stem Cells
new specialized cell function.
‘Cell culture’ is a term that refers to the growth and
A stem cell is defined as ‘a cell that has the ability to maintenance of cells in a controlled environment
continuously divide and produce progeny cells that outside an organism. A successful stem cell culture is
differentiate (develop) into various other types of cells or the one that keeps cells healthy, dividing and
tissues.’ “Stem cells are like little kids who, when they unspecialized.
grow up, can enter a variety of professions,” Dr Marc
Dental pulp stem cells can be cultured by following
Hedrick of the UCLA School of Medicine says. “A child
two methods:
might become a fireman, a doctor or a plumber, depend-
ing on the influences in their life or environment. In 1. Enzyme-digestion method: In this method, the pulp
tissue is collected under sterile conditions and
digested with appropriate enzyme; the resulting
cell suspensions are incubated in culture dishes
containing a special medium supplemented with
necessary additives. Finally, the resulting colonies
are subcultured before confluence and the cells are
stimulated to differentiate.
2. Explant outgrowth method: In this method, the
extruded pulp tissues are cut into 2.0 mm3 cubes,
shifted to a suitable substrate and are incubated
directly in culture dishes containing essential
medium. Ample time (up to 2 weeks) is needed to
allow a sufficient number of migrants out of the
tissues.

Classification of Stem Cells

38
i. Stem cells are classified as:
• Embryonic/fetal: Mostly cells are embryonic, so term
Fig. 38.1 Triad of regenerative procedure embryonic is preferred.

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 630 Essentials of Endodontics

• Postnatal/adults: Cells are similar at all age groups, iii. Stem cells have been classified, based on their source
so term postnatal is preferred. of genesis:

Embryonic/fetal Postnatal/adults Allogenic Xenogenic Isogenic Autologous

• Derived from inner cell • Any stem cells taken from From same From individual From geneti- From the
mass of early embryo mature tissue. species (e.g. of other species cally identical same indivi-
called blastocyst. • They are lineage restricted blood cells, (blood cells, individual dual to whom
• Capable of dividing and and are referred to by their bone marrow, bone marrow (twins) (any required
renewing themselves for tissue of origin. cells of same cells of other cell to be (any cell to be
long periods without • Play an important role in species) species) implanted) implanted)
differentiating whereas adult local tissue repair and
stem cells cannot regeneration. Most stem cells found in the orofacial region are
• For example: Embryonic stem • For example: Dental pulp
mesenchymal stem cells (Fig. 38.2). Flowchart 38.1
cells can differentiate into any stem cells (DPSC), Stem
summarizes forms of dental stem cells.
type of specialized cells like cells from exfoliated
Hematopoietic cells, Hepatic deciduous teeth (SHED), The various postnatal mesenchymal cells can differen-
cells, osteoblasts, vascular etc. tiate into odontoblast-like (dental) cells.
endothelial cells, etc.
b. Growth Factors
ii. Stem cells are also classified according to their source Growth factors are proteins that bind to receptors on
and range of differentiation: the cell and induce cellular proliferation and/or
differentiation. Many growth factors are quite versatile,
Type Source
stimulating cellular division in numerous cell types,
Totipotent Cells from early (1–3 days) embryos (each while others are more cell specific. Dentin contains
cell can develop into a new individual)
many proteins capable of stimulating tissue responses.
Pluripotent Some cells of blastocyst (5–14 days) [cells It is hypothesized that the therapeutic effect of calcium
can form any (over 200) cell types] hydroxide may be because of its ability to extract
Multipotent Fetal tissue, cord blood, and postnatal stem growth factors from the dentin matrix. These growth
cells including dental pulp stem cells (cells factors play a key role in stimulating tertiary
differentiated, but can form a number of dentinogenesis, an accepted response of pulp-dentin
other tissues)
repair.

38 Fig. 38.2 Potential source of stem cells in oral environment (Schematic representation: Adapted from Hargreaves et al
2013)

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 Regenerative Endodontics 631

Flowchart 38.1: Forms of dental stem cells

• Growth factors, especially transforming growth Table 38.1 Growth factors and cellular activity
factor (-TGF) are important for odontoblast Growth factor (source) Cellular activity
differentiation and stimulation of dentin matrix
Bone morphogenic protein Induces differentiation of osteo-
secretion. (BMP) (bone matrix) blasts; stem cells synthesize
• Another important growth factors in regeneration secrete mineral matrix, subse-
is bone morphogenic proteins (BMPs). Recombinant quently bone mineralization
human bone morphogenic protein (BMP) stimulates Epidermal growth factor (EGF) Promotes proliferation of
differentiation of osteoblasts; subsequently, bone (submaxillary glands) mesenchymal and epithelial
cells; increase stem cell
mineralization.
numbers
• Fibroblast growth factors (FGF) are for general
Fibroblast growth factor (FGF) Promotes proliferation of
growth-promoting effects on most fibroblastic cells; (a wide range of cells) many cells; increase stem
it stimulates angiogenesis wound healing and cell cell numbers
migration in vivo. Insulin-like growth factor I or Promotes proliferation of many
• Platelet derived growth factor (PDGF) are derived II (IGF I or II; variety of cells) cell types; increase stem cell
from platelets and endothelial cells; promotes numbers
connective tissue cells. Platelet-derived growth factor Promotes proliferation of
(PDGF) (platelets, endothelial connective tissue; increase
The common growth factors, their source and cellular cells, placenta) stem cell numbers
activity is tabulated in Table 38.1.
Transforming growth factor Anti-inflammatory, promotes
(-TGF) (dentin matrix, wound healing, inhibits macro-
c. Scaffolds activated T-helper cells phage and lymphocyte
A scaffold is an artificial three-dimensional frame proliferation; used to promote
mineralization of pulp tissue
structure that serves as a mimic of extracellular matrix
Nerve growth factor (NGF) Survival and maintenance of
for cellular adhesion, migration, proliferation, and
(protein secreted by neuron’s sympathetic and sensor y
tissue regeneration in three dimensions. tissues) neurons; promotes neuron out-
growth and neural cell survival
Ideal Requirements of a Scaffold
• Biocompatible Types of Scaffold
• Biodegradable a. Biological/natural scaffolds
• Promote cell attachment, spreading and proliferation These consist of natural polymers, such as collagen and
• Strong enough to hold matrix glycosaminoglycan, which offer good biocompatibility
and bioactivity. Collagen is the major component of the

38
• Good transport properties
extracellular matrix and provides great tensile strength
• Easy to connect to host’s vascular system to tissues. As a scaffold, collagen allows easy placement
• Conducive surface characteristics. of cells and growth factors and allows replacement and

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 632 Essentials of Endodontics

natural tissues after undergoing degradation. However, • Synthetic hydrogels, including polyethylene glycol
it has been reported that pulp cells in collagen matrices (PEG) based polymers.
undergo marked contraction, which affects pulp tissue • Scaffolds modified with cell surface adhesion peptides
regeneration. For example; such as arginine, glycine and aspartic acid to improve
• Collagen/dentin matrix cell adhesion and matrix synthesis within the three
• Glycosaminoglycan dimensional network.
• Fibrin c. Scaffolds containing inorganic compounds
• Platelet rich plasma (PRP). Scaffolds containing inorganic compounds, such as
Platelet rich plasma (PRP): An ideal scaffold hydroxyapatite (HA), tricalcium phosphate (TCP) and
Platelet rich plasma (PRP) is being established as a calcium polyphosphate (CPP) are used to enhance bone
potentially ideal scaffold for regenerative endodontic conductivity and have proved to be very effective for
treatment regimen. An ideal scaffold selectively binds tissue engineering of dental pulp stem cells.
and localizes cells, contains growth factors and under-
goes biodegradation over time. PRP contains growth Clinical Applications of Tissue Engineering
factors, stimulates collagen production, recruits other Clinical techniques, whereby the tissues can be regene-
cells to the site of injury, produces anti-inflammatory rated, include the surgical implantation of laboratory
agents, initiates vascular ingrowth, induces cell differen- grown synthetic pulp and dentin tissues; implanting a
tiation, controls the local inflammatory response and mix of scaffold and growth factors and promoting
improves soft and hard tissue wound healing. endogenous recruitment of stem cells; or enhancing
It has increased concentration of growth factors that revascularization into root canals by encouraging stem
have the potential to attract stem cells present in the cells to grow into natural fibrin clots.
apical tissues (vital pulp cells, periodontal ligament, On the basis of aforementioned principles of tissue
apical dental papilla, bone marrow) and even from engineering, the procedures for regenerating endo-
periapical lesions. dontium can be carried out following two approaches:
Preparation of PRP involves taking—blood sample a. Creating an engineered tissue constructed in the
from the patient’s arm (20 ml approximately); centri- laboratory and transplanting the same into the
fuging the blood in the presence of an anticoagulant, recipient tooth (pulp cavity).
removal of erythrocytes from the blood, and adding
b. Revascularization: Inducing host stem cells from the
thrombin and calcium for coagulation of prepared PRP.
adjacent site to mobilize and inhabit the implanted/
It is then injected into the canal space up to the level of
natural host matrix.
slightly short of coronal opening and allowed to clot
for 5 minutes. Approximate 3.0 mm of grey MTA is a. Implanting laboratory constructed tissue into the
placed directly over the PRP clot. The PRP clot provided Pulp Cavity
an excellent matrix for placement of MTA. Subse-
quently permanent restoration is placed to prevent The advancements in tissues engineering techniques
coronal leakage. facilitate stem cells be implanted onto a three dimen-
sional conductive scaffold matrix rich in bioactive
Advantages signaling molecules. The artificial pulp generated in the
• Relative ease of application laboratory can be transplanted into the pulp cavity of
• Shorter time to induce vital tissues within the root the recipient tooth. However, construction of precise
canal system. 3D models for each individual pulp cavity is difficult.
Highly complex and variable internal anatomy amongst
Disadvantages
the teeth and also variations from tooth to tooth and
• Need of special equipment and medications to
individual to individual makes the task quite difficult.
prepare PRP in young patients.
• Increased cost of the treatment. Injecting a soft scaffold matrix impregnated with
pulp stem cells and growth factors into the root canal
b. Artificial synthetic scaffolds system can overcome difficulties associated with
These are synthetic polymers with controlled physico- implanting a rigid matrix. Scaffold material that can be
chemical features such as degradation rate, micro- injected includes synthetic hydrogels like polyethylene

38 structure, and mechanical strength; for example:

• Polylactic acid (PLA), polyglycolic acid (PGA) and their
copolymers–polylactic-co-glycolic acid (PLGA), etc.
glycol polymers. Though delivery system is relatively
easier with these polymers, problems of low cell
survival and limited control over tissue formation exist.

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 Regenerative Endodontics 633

Modifying hydrogel polymers with peptides like

arginine, glycine or aspartic acid have helped in
improving cell adhesion and matrix synthesis rendering
them suitable for use. Making the hydrogels photo-
polymerizable (injectable scaffold) so that they form a
rigid framework after implantation into the receptor
site is a better solution. Mineralizing genes have also
been implanted into the pulp to promote tissue
mineralization. Viruses have been genetically modified
to hold human DNA. Therapeutic DNA can directly
be inserted or transported to the membrane of the target
cells through artificial lipid carrier. The ability to use
this system in vivo need to be further evaluated. The Fig. 38.3 Conventional vital pulpotomy: (a) Removal of
conventional pulpotomy and regeneration of dentin- coronal pulp; (b) Placement of MTA and restorative material;
pulp organ is depicted in Figs 38.3a to c and 38.4a to d, (c) Dentin bridge formation (no effect on dentin-pulp complex)
respectively.
odontoblasts, fibroblasts and also endothelial cells
Cell Homing (Fig. 38.5 a to d).
Cell homing refers to two cellular processes; implanting Cell Homing is applicable to restoration of pulp
and cell differentiation. The mesenchymal stem/ vitality of both immature and mature permanent teeth.
progenitor cells having capacity to differentiate into Cell Homing has the advantage wherein patient’s own
various cell lineages forming dentin-pulp tissues are mesenchymal cells are implanted into endodontically
implanted into the root canal. Differentiation implies prepared root canals and induce them to differentiate
transformation of these stem/progenitor cells into into pulp cells/odontoblastic lineage.

Fig. 38.4 Regeneration of dentin-pulp complex: (a) Residual pulp; (b) Implantation of growth factors and scaffolds;
(c) Induced progenitor cells (stem cells) from pulp; (d) Regeneration of pulp-dentin complex

Fig. 38.5 Cell homing approach (diagrammatic): (a) Normal tooth with periapical lesion; (b) Root canal prepared;
(c) Placement of scaffold into root canal; (d) Proliferation of stem cells
38

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 634 Essentials of Endodontics

b. Revascularization (Inducing Endogenous Stem maturation of fibroblasts, odontoblasts, cementoblasts,

Cells Grow in Natural Fibrin Clot) etc. from the immature, undifferentiated mesenchymal
Revascularization is the procedure to re-establish the cells in the newly formed tissue matrix.
vitality in a nonvital tooth to allow repair and regenera-
Advantages
tion of tissues.
The advantages of revascularization are:
Revascularization procedure is based on the concept
that if a sterile matrix is provided in which new cells • Requires short treatment time: After control of
infection, can be completed in a single visit
can grow, pulp vitality can be re-established. Necrotic
pulp, if free from infection, provides a matrix into which • Cost-effective; number of visits are reduced, and no
cells from periapical tissues grow and re-establish additional material required
pulp vascularity, slowly replacing necrotic tissue. In • Obturation of the canal is not required unlike in
immature infected nonvital teeth, an infection-free calcium hydroxide-induced apexification
matrix is created by use of irrigants and/or tri-antibiotic • Continued root development (root lengthening) and
pastes. This matrix acts as the scaffold for the regenera- strengthening of the root as a result of reinforcement
tion of new pulp tissues. of lateral dentinal walls with deposition of new
dentin/hard tissues can be achieved successfully.
Mechanism of revascularization: The possible
mechanism of revascularization includes: Limitations
The limitations of revascularization are:
Vital apical pulp cells: It is speculated that a few vital
• Long-term clinical results are yet to be documented.
pulp cells always remain at the apical end of the root
canal. These cells might proliferate into the newly • The entire canal might get calcified; potentially
formed matrix and differentiate into odontoblast under increasing the difficulty in future endodontic proce-
dures, if required.
the organizing influence of cells of Hertwig’s epithelial
root sheath, which are quite resistant to destruction, • Procedures are limited to the open apices, immature
even in the presence of inflammation. The newly teeth.
formed odontoblasts can lay down atubular dentin at • In case post and core are the final restorative treat-
the apical end (apexogenesis); also on lateral walls of ment plan, revascularization is not the right
the root canal, thus reinforcing and strengthening the treatment option because the vital tissue in apical
two-thirds of the canal cannot be violated for post-
root.
placement.
Multipotent stem cells: Multipotent dental pulp stem cells
present in abundance in immature teeth are responsible Clinical Procedure
for continued root development. These cells from the The clinical procedure followed in revascularization
apical end might get into the existing dentinal walls includes:
and differentiate into odontoblasts; deposit tertiary/
atubular dentin. Case Selection
Necrotic pulp/immature pulp is a reasonable candidate
Stem cells in periodontal ligament: The stem cells present of regenerative endodontic procedures.
in the periodontal ligament can proliferate, grow into Young patients (6–8 years of age) are preferred,
apical end and within the canal to deposit hard tissues though success has been observed in older age group
both at the apical end and also on the lateral walls. patients also. The size of the apical opening has definite
Stem cells from apical bone/apical papilla: Instrumentation effect on the successful regenerative potential. Short and
beyond the confines of the root canal to induce bleeding open root is more conducive to ingrowth of tissue,
can also transplant mesenchymal stem cells from the because of presence of increased number of apical
apical bone into the canal lumen. These cells have papilla cells. Ideally the size of the apical opening
extensive proliferating capacity. should be greater than 1.0 mm, though a few authors
have observed successful ingrowth even with an apical
Blood clot: Blood clot, being a rich source of growth opening as less as 0.3 mm.
factors, could play an important role in regeneration. The cases to be excluded are: avulsed teeth

38
These include platelet-derived growth factor, platelet- immediately after replantation (revascularization may
derived epithelial growth factor, and tissue growth occur naturally in them), tooth cannot be adequately
factor, which may stimulate differentiation and isolated, teeth with extensive loss of coronal tissue that

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 Regenerative Endodontics 635

require restoration with a post, medically compromised The third stage includes stimulating bleeding and
patients, patients on anticoagulants and with previous placing scaffold.
history of apical surgery. The initial treatment is assessed thoroughly to ensure
Compliance of patient is essential. Patient should be no sensitivity to palpation and percussion. If signs/
informed of all the possible implications and make an symptoms of infection persist, additional treatment
informed consent. time with antimicrobial or use of alternative anti-
microbial is recommended.
Procedure The area is anesthetized (epinephrine should be
The first stage includes local anesthesia, rubber dam avoided as it prevents blood flow to create a scaffold)
and isolated with rubber dam.
isolation and access preparation, followed by copious
Antibiotic paste/calcium hydroxide is removed by
and gentle irrigation. No instrumentation is carried out
copious irrigation using EDTA. (EDTA removes smear
during regenerative procedures (use of instruments is
layer and exposes dentinal tubules. It also stimulates
limited to removal of loose/necrotic pulp tissue; no
and conditions the dentin to release growth factors).
instrumentation of canal walls). Hence, there is a need to
Bleeding is created into canal system by over
rely heavily on chemical débridement and the use of instrumenting (blood clot consists of a network of fibrin
intracanal medicaments to achieve disinfection and platelets, red blood cells and white blood cells).
resolution of infection. The canal is finally irrigated with 5.0 ml normal
The selection of irrigant should not only be based saline. After drying the canal, a sterilized pre-bent H-
on bactericidal property, but also ability to promote the file is used to cause mechanical irritation of the
survival and proliferative capacity of the patient's stem periapical tissues. The canal is allowed to be filled with
cells. blood; wait for 15 minutes for the blood to clot.
1.5% sodium hypochlorite is preferred, followed by
normal saline; lower concentration of sodium Clinical Tips
hypochlorite minimizes cytotoxicity to stem cells in the • Place a small bend in the file, dip the file in EDTA and over
apical tissue (Chlorhexidine is known cytotoxic to stem instrument to achieve blood clot just below the cemento-
cells and should be avoided, especially in the second enamel junction (coronal openings).
appointment). 5.0 ml of normal saline minimises the • In canals where a blood clot cannot be evoked, blood from
adjacent canals can be placed in the canal under treatment to
cytotoxic effect of sodium hypochlorite on vital tissues. create a clot.
The second stage includes placement of antibiotic
paste or calcium hydroxide after drying the canal. Autologous fibrin matrix (AFM) can be preferred as
i. Calcium hydroxide is effective as an antimicrobial, a 3D scaffold than a blood clot with increased concen-
but it has certain limitations: tration of growth factors. Use of AFM is advantageous,
• Calcium hydroxide limits the possibility of being easy to collect, provides a 3D scaffold and
increasing the root canal wall thickness. supplies a concentrated source of growth factor.
• Effectiveness limited to the root canal only with Platelet rich fibrin (PRF) is commonly used auto-
inadequate dentin penetration. logous fibrin matrix. It is rich in pre-existing growth
ii. Triple antibiotic paste is very effective (1:1:1 by factors like PDGF, TGF-, etc., which helps in
volume of ciprofloxacin/metronidazole/mino- migration of fibroblasts and endothelial cells. Platelet
cycline (0.1 mg/mL). rich fibrin is prepared by collecting venous blood
Note: Undiluted slurry of antibiotics is cytotoxic to stem from the patient without anticoagulant. It employs
cells. Dilution of 1000 times (or g/ml) is necessary for stem a centrifuge kit and a collection kit. The blood is
cell survival and proliferation. Calcium hydroxide is still a immediately centrifuged at a speed of 2700 rpm for
preferred choice. 12 minutes. The resultant product consists of PRF
Minocycline may stain dentin; however, staining can clot in the middle and RBC at the bottom.
be avoided by: Once bleeding has been evoked or AFM has been
• Sealing the pulp chamber with dentin bonding agent injected, place a collagen matrix, such as Collaplug or
or flowable composite Collacote at the orifice (prevents over extension of
• Elimination of minocycline from the composition restorative material). A case, achieving revascularization
and use as double antibiotic paste in deciduous first molar, is depicted in Fig. 38.6a to d.
• Cefaclor is used in place of minocycline.
The canal is sealed with appropriate temporary
material.
Place 3.0–4.0 mm of MTA over the collagen matrix
to provide a seal (white MTA may stains dentin, GIC
can be used as an alternate in esthetic areas).
38

t.me/Dr_Mouayyad_AlbtousH
 636 Essentials of Endodontics

Materials used for Sealing

The materials currently available for sealing the teeth
intended for revascularization are Mineral Trioxide
Aggregate (MTA), Bioceramics, Glass-ionomer cement
and Calcium enriched mixture (CEM).

Mineral Trioxide Aggregate (MTA)

MTA has been successfully used as a sealing agent along
a b with glass-ionomer cement in the revascularization
process. It is biocompatible and osseoconductive and
sets in the presence of moisture. However, it does not
strengthen the remaining tooth structure (Fig. 38.7a to h).
A clinical case of revascularization with MTA is
shown in Fig. 38.8a and b.

Bioceramics
c d
Bioceramics have also been successfully tried for sealing
Fig. 38.6 Revascularization using plasma rich fibrin (PRF) in of root canals and as root repair materials. Their alumi-
deciduous first molar: (a) Immature apex and periapical nium free composition makes them more biocompatible
radiolucency in relation to mandibular first molar; (b) Plasma
as compared to MTA. The ability to form hydroxy-
rich fibrin (PRF) prepared; upper layer of plasma, fibrin clot
and RBC’s below; (c) Placing PRF in canals; (d) Post- apatite while setting and then easy availability makes
operative radiograph showing closure of apex and root them the choice of materials for the apexification
development (at six month follow-up) procedures.

38 Fig. 38.7a to h Revascularization using MTA as sealing agent

t.me/Dr_Mouayyad_AlbtousH
 Regenerative Endodontics 637

• Control over growth factors is mandatory to get

desired quality results
• Appropriate biodegradable scaffolds are required for
formation of engineered tissues
• Isolation and organization of dental stem cells for
regeneration procedures is practically challenging
• Procedural problems, such as discoloration,
insufficient bleeding, etc. should also be taken
care of.
There is a need for biologically based endodontic
a b procedures that offer the potential to replace tissues
lost due to trauma or disease. Regenerative endodontic
Fig. 38.8 Revascularization using MTA in maxillary left
central incisor: (a) Incomplete root formation; (b) Recall
procedure of future will involve cell biologist and also
at six months showing root apex formation the concept of tissue engineering so as to achieve
successful results.
Glass-Ionomer Cement
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38

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 Chapter
39
Ethics in Endodontics

The word ethics is derived from a Greek word ‘ethos’ to evaluate human activities; especially, the concepts
meaning ‘conduct’ or ‘character’. It is the philosophy of goodness and obligation. Ethics may be defined as ‘a
of human conduct, a way of stating and evaluating normative study that deals with the conduct of human beings
principles by which problems of behavior can be solved. in private or in public’. Ethics is thus, a normative science,
In simple terms ‘Ethics’ is the ability to know the not a descriptive one. The descriptive science deals with
difference between what you consider as a right to do the factual truths; whereas, moral values are evaluated
and what is right to do. Ethics is the philosophy of in a normative science. Ethics does not teach us what
human conduct or the science of what is morally right. to do; rather it seeks to find out what should be the
The conduct is a voluntary action carried out without base for our actions. It is a search for principles that
any compulsion and the ethics is concerned with guide our conduct and moral perceptions in the society.
evaluating the human conduct and judging whether Other two branches of philosophy, i.e. metaphysics
the action is right or wrong. Ethics is interchangeably and epistemology also have a bearing on ethics.
used with the word ‘moral’ (latin word mores: meaning Metaphysics is concerned with our perception of
conduct or habits). Collectively ethics are only moral ultimate nature of reality. Epistemology deals with the
obligations, not imposed by any law. A few professions conditions under which our claims to knowledge and
may have written ethical codes; however, basic belief are either valid or invalid. The relation between
principle should be followed by one and all. Dental ethics and epistemology is well-described by forensic
ethics implies moral duties and obligations of the dental science, which defines the ethicolegal status of an action
professionals towards patients, colleagues and the on the basis of evidence of facts.
society at large. The nucleus of ethics is moral behavior, which
A few authors have notified ETHICS alphabets develops in following three stages:
as, E: Expertise, T: Truthful, H: Honesty, I: Integrity, Stage 1: Person decides what is ‘right’ or ‘wrong’ on
C: Compassion and S: Sagacity. the basis of inborn/innate feelings.
Ethics and society are interrelated and influence each
Stage 2: Those forms of conduct is considered ‘right’
other. Individuals following ethics make better society.
which were approved by customary modes of behavior
The gap between general and professional ethics is
in the society.
marginal. There is difference of degree only and not of
quality. For example, ‘do not steal’, a principle in Stage 3: It is the individual’s conscience with his capacity
general ethics is equally applicable to the professional to judge what is ‘right’ and what is ‘wrong’.
ethics. Usually our moral judgments are not decided on the
The code of dental ethics, created by American basis of instincts or customs. The transition from
Dental Association, serve as a standard to which all customary to conscience/reflective morality makes the
dental professionals should adhere with sincerity. Each individual responsible for his/her choice of action.
member of dental fraternity is responsible for The ethical postulates to be followed are:
maintaining the ethical standards of the profession. • To differentiate between right and wrong actions
Ethics is one of the three branches of philosophy (know the difference between right and wrong).
(other two are metaphysics and epistemology) that is • Knowledge of morality make a genuine impact on
concerned with study of those concepts that are used human behavior.

640

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 Ethics in Endodontics 641

• Despite certain constraints, one has the capacity to life, all thanks. But it may also be within my power
exercise one’s rationality to make moral decisions. to take a life; this awesome responsibility must be
• Individual’s capacity to fix priority of decisions. faced with great humbleness and awareness of my
own frailty. Above all, I must not play at God.
History of Ethics • I will remember that I do not treat a fever chart, a
The ‘Hippocratic oath’ has been regarded as a standard cancerous growth, but a sick human being, whose
of professional ethics. Descriptive theories define the illness may affect the person’s family and economic
meaning of good; may be moral or non-moral stability. My responsibility includes these related
characteristics. Prescriptive theories define ethical terms problems, if I am to care adequately for the sick.
as carrying mandatory force, e.g. ‘ethical rules for • I will prevent disease whenever I can, for prevention
dentists’ framed by Dental Council of India. Various is preferable to cure.
theories have been put forward regarding ethics: • I will remember that I remain a member of society,
1. Theory of utilitarian ethics: Focuses on utility. with special obligations to all my fellow human
2. Theory of deontologic ethics: Focuses on morality of act beings, those sound of mind and body as well as the
rather than its consequences; emphasis on action infirm.
irrespective of the consequence and do not compro- • If I do not violate this oath, may I enjoy life and art,
mise with duty. respected while I live and remembered with affection
3. Theory of virtue ethics: Focuses on what a virtuous thereafter. May I always act so as to preserve the
person would have reacted in a particular circum- finest traditions of my duties and may I long
stance. experience the joy of healing those who seek my help.

Modern Version of the Hippocratic Oath (Revised Ethical Dilemmas

in 1964 by Louis Lasagna) The specific problems and moral issues emerged due
In India, The Dentist Act was amended via section 17A to changed modern circumstances for dealing with
(amendment in August 1988) empowering the Dental patients are called Ethical Dilemmas. A branch of
Council of India to prescribe standards of professional normative ethics, which deals with these specific ethical
conduct and etiquettes. problems is called ‘Applied Ethics’. It includes (a) medical
The famous ‘Hippocratic Oath’ written in 4th ethics, (b) business ethics, (c) media ethics, (d) legal
Century BC, is still the nucleus of professional ethics. ethics and (e) environment ethics.
The initial version ‘do no harm’ has been modified and The principles followed for making decisions in the
considered as the nucleus of modern version of the ethical dilemmas are:
Hippocratic Oath. 1. Analyzing: Dividing a problem into its leading
I swear to fulfil, to the best of my ability and judg- alternatives.
ment, this covenant: 2. Weighing: Assessing the strength and weakness of
• I will respect the hard-won scientific gains of those alternatives by balancing one against the other.
physicians in whose steps I walk, and gladly share 3. Justifying: Providing a compelling and sufficient
such knowledge as is mine with those who are to moral reason that appeal to an established moral
follow. principle such as to tell the truth.
• I will apply, for the benefit of the sick, all measures 4. Choosing: Selecting alternatives for which some
which are required, avoiding those twin traps of justification can be made.
overtreatment and therapeutic nihilism. 5. Evaluating: Re-examining the choice and the
• I will remember that there is art to medicine as well justification based on one’s exposure to other similar
as science, and that warmth, sympathy, and under- moral issues.
standing may outweigh the surgeon’s knife or the
chemist’s drug. Code of Dental Ethics
• I will not be ashamed to say “I know not,” nor will I A profession consists of a limited group of persons who
fail to call in my colleagues when the skills of another have acquired some special skill and are able to perform
are needed for a patient’s recovery. that function in society better than an average normal
• I will respect the privacy of my patients, for their person. A professional person is expected to have
problems are not disclosed to me that the world may
know. Most especially, must I treat with care in
matters of life and death. If it is given me to save a
respect for human beings, competence in his chosen
field, integrity and primary concern with service rather
than with prestige and profit. A systematic set of rules
39

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 642 Essentials of Endodontics

is needed that upholds the dignity and honor of any regularly, and under all constraints, can perform the
profession upgrading its standards and sphere of procedure in the best interest of the patients.
usefulness. The members of the concerned association
should understand their duties and obligations, not 2. To Do Good (Beneficence)
only to their fellow beings but also to the society. Ethical Doctors are generally equated to God and it is our moral
codes are the result of an attempt to direct moral duty not to abuse this power.
consciousness of members of the profession to a The healthcare professionals are expected to initiate
peculiar problem. Hippocrates wrote first voluntary beneficial actions for their patients honoring an
code of regulations for medical profession, protecting unspoken agreement between the doctor and the
the rights of patients and appealing to finer instincts of patient that some good will result.
physicians. Standards for protection of human subjects The dental professionals must realize that it is not
were created in 1947 and called ‘Nuremberg Code’. enough to feel satisfied that the treatment will not cause
In dentistry, the American Dental Association’s any harm to the patient. Make sure that endodontic
(ADA) principles of ethics are followed in routine, therapy/restorative treatment or re-evaluation at a later
labelled as a code of ethics and conduct. This code date will definitely be for the benefit to the patient and
contains five major sections: relieve them of their discomfort.
1. Service to public and quality of care This principle can be explained as ‘there are two
2. Education types of bad people—those who do bad things; and
3. Governing the profession those who see bad things and do not make any attempt
4. Research and development to rectify them’.
5. Professional announcement. If the patient’s previous treatment is unsatisfactory
(say partial endodontic treatment or an overhanging
Ethical Principles restoration) causing pain or discomfort, it is the duty
The fundamental duty of a dental surgeon is to achieve of the operating doctor to do his/her level best without
proper ethical conduct in a dental setting; the patient’s undermining and abusing the other doctor. Your work
interest and needs should be balanced. For maintaining will convey the clear message of your supremacy of
the balance, the following principles of ethics are the subject.
prescribed. 3. Respect for Persons
1. To Do No Harm (Non-maleficence) One of the most important principles, respect for persons,
incorporate two fundamental ethical considerations,
This is the foundation of social morality, which states
namely:
that dental surgeon should not cause any unnecessary
harm to the patients specifically. a. Autonomy: Autonomy implies that healthcare
‘Conservative Dentistry’ literally embodies the professionals respect the patient’s capacity for self-
principle, which implies that preservation of what determination in making decision concerning their
remains is more important than the meticulous treatment.
replacement of what is lost. Newer methods of cavity Patients should be explained the pros and cons of
preparation and recent advances in material technology their decision and should be allowed to abide by their
are already providing attractive minimal invasive decision, whether or not the operator believe that these
options for treatments that once required extensive choices are wise or beneficial (in case of discontentment
unnecessary removal of tooth structure. the patient is referred to another dental surgeon for
Endodontists must explain alternatives to patients opinion).
as regard restorative aspects. Implants are an enticing During planning the treatment, the patient should
lucrative business currently in vogue; however ethically be an active participant and not as a mere by stander.
speaking, if the damaged tooth can be salvaged, all More often we, the dental surgeons, are guilty of
measures must be taken to preserve it by endodontic withholding information, restricting choices or making
treatment and an adequate postendodontic restorations. choices for the patient without their consent, even if
In case where pain cannot be avoided, all appropriate we believe that the decision is in ‘best interests of the
measures must be attempted to minimize the pain patient’.

39 during treatment. The aim should be to provide

‘painless endodontics’ to all the patients. It is imperative
that the dental surgeons must update their knowledge
Restoring some adjoining teeth when patient ask for
a specific restoration, or propagating the use of a
particular material insisting it is the best option, must

t.me/Dr_Mouayyad_AlbtousH
 Ethics in Endodontics 643

be avoided as misleading the patients is always disadvantages, associated risks, need for treatment as
unethical and may lead to legal hassles. well as the future prognosis to some extent.
b. Informed consent: ‘Informed Consent’ is an essential Step 2: Patient understand the process (may be by
component of respecting a person under ethical norms. reading the document or by narrating the same in his/
The attributes of informed consent (Nuremberg code) are: her language) and based upon this understanding
• It should be voluntarily given by the patient. either agrees or refuses to undergo treatment.
• It should be legally valid. A list of information conveyed to the perspective
• It should be informed. patient/subject includes:
• It should be comprehending. i. A statement that the study involves research
In certain populations, the concept of individual coupled with explanation of the purpose of
autonomy may be comprehended. In such situations, research and expected duration of subjects’
informed consent is negotiated with a leader. This can involvement. A description of the procedure
also be followed in cases where persons because of followed should also be identified.
illiteracy or otherwise cannot participate actively. The ii. A description of any benefit to the subjects.
ethical principles require special justification before iii. A description of any reasonably foreseeable risks
treatment is carried out on vulnerable individuals. or discomforts to the patient.
Vulnerable population also includes women who might iv. Whether any medical treatment available during
be subservient to their spouses. Women may or may risk.
not be literate, but should participate in discussion. v. Availability of alternative procedure, if any.
Illiteracy may not create any problem because informed vi. A statement highlighting how the confidentiality
consent can be taken by talking rather than reading. This of records will be maintained.
empowers even women to protect their own interests. vii. Availability of person(s) for answer to pertinent
The ‘Consent Form’ is an instrument designed to questions about ongoing research.
protect the interests of the investigators and their viii. A statement that participation is voluntary and
institutions; and also to defend them against any civil refusal to participate will involve no penalty or loss
or criminal liability. The informed consent actually of benefits to which the subject is otherwise entitled
consists of two steps. In first step, the investigator/ and the subject may discontinue participation at
operator presents whole of the information regarding any time.
the procedure to the subject/patient and in second step, These eight features are known as ‘Elements of
his queries about that procedure are cleared. Information’ in the informed consent.
Step 1: Information is presented to the patient regard- Informed consent must be recorded in every case
ing the procedure to be undertaken, advantages, along with date and must be duly signed by the patient.

Informed Consent of Endodontic Treatment

In case not opting for endodontic treatment, the options may be:
• Extracting the tooth
• Endodontic surgery
In case opting for endodontic treatment (endodontic treatment may have 5–10% failure rate); the possible risks and complications
may be:
• Pre-existing gum disease requiring additional treatment
• Problems due to local anesthesia
• Instrument separation
• Perforation of the canal
• Infection, discomfort, numbness
• Allergic/adverse reaction of the materials used
• Tooth fracture
• Incomplete healing
After endodontic therapy, it is important to restore the tooth as early as possible (say within two weeks).
I understand that endodontic therapy may have 5–10% failure rate under optimal conditions. I agree to face the problems, if
any. I have had the opportunity to ask questions and all my questions have been answered to my satisfaction. I trust the operative
capabilities of my doctor and I hereby offer my consent to have root canal treatment for tooth .............. .
Diagnosis: ............................................................................................................................................................................................
Clinical/Radiological findings: .............................................................................................................................................................
Name of patient/guardian Signature Date 39

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 644 Essentials of Endodontics

4. Justice Advertising in Dentistry

Justice is described as fairness and equal acceptance Advertising has traditionally been seen as a contro-
given to other individuals. The principal of justice, versial issue especially for health professionals. The use
emphasising on equality, calls for an obligation to of advertising media to promote a professional practice
protect the weaker section of the society and to ensure is relatively new in medical field. However, advertising
equality in their rights and benefits. by healthcare professionals in India has increased
It is the society which determines what is just and dramatically during the past decade, and this trend in
unjust; therefore, it is imperative that dental surgeons all probability is to continue.
should be in touch with society for ethical compliance Three types of advertising commonly used amongst
of justice. dental professional are:
The dental professional in general and endodontist a. Comparable advertising
in particular can offer discount services to needy or b. Competitive advertising
spare some time in clinics for low income patients. c. Informational advertising.
They can support local or state level program that
a. Comparable advertising is the use of comparisons
seek to extend oral healthcare to the needy people in
between the advertiser and others in the same market.
society.
An example of ‘comparable’ type of advertisement,
5. Truthfulness (Veracity) which states that Dr X is the ‘only dental surgeon
recognized as a Master’. These are usually seen as
Veracity implies being truthful and respecting the trust
statements of superiority. Such advertisements can
that is essential in patient–doctor relationship. The
easily be misinterpreted by the public; so considered
patient–doctor relation being based on trust, lying of
false and misleading. A few professionals claim
any kind may jeopardize the relations.
that advertising one’s achievements is informational
It is unethical to recommend any unnecessary and not a statement of superiority. Explanation may
treatment to the patients and also charging for the and may not be convincing; however, such advertise-
treatment procedures which was never carried onto the ments must not mislead the patients and therefore
patients (doctor may charge for two restorations when should be used with caution. Advertisements regarding
only one tooth was restored). Unnecessary referral is superiority are comparative and not information,
also considered unethical. Advertisements based on since they promote the impression that the particular
partial truths are also sort of lying to patients. Another dental surgeon is superior to or better than others in
area of veracity (truthfulness) is the credential of the the field.
dental surgeon. Any fake degree or specialization as
shown by the doctor lead to ‘lying’; subsequently, guilty b. Competitive advertising implies offering discounts on
of diluting this ethical principle. dental procedures or offering of the same product or
service for less cost than others in the same market. A
6. Confidentiality few dental surgeons have seen offering discounted
Patients have the right to expect that all communica- services, such as ‘fillings free with ortho treatment’, or
tions and records pertaining to their case will be treated ‘one child will be treated free if parents are also
as confidential. The relationship of patient and the patients’, or ‘free treatment for first five patients’ and
doctor is based on the understanding that any so on.
information revealed by the patient will not be divulged c. Informational advertising is the most acceptable mode
without the patient’s consent. of advertisement in medical field. It is the use of
In the field of conservative dentistry, which pertains information that only pertains to the advertiser and
largely to esthetics as well, the operator may advertise/ does not refer to any other service providers. This type
display the pre- and post-treatment photographs; of advertisement informs the selected population of the
however, in doing so without the consent of the patient, person (advertiser), the advertiser’s location, and the
would undeniably break a bond of trust between the services available from the advertiser. It also
dental professional and the patient. In case the dental communicates general information regarding the
surgeon has some personal relations with the patient, services to educate the target audience. These types of

39 it is important to understand that in professional

dealing, the personal and professional relationship will
have to be dealt separately.
advertisements generally comply with various state
ethical codes and the ADA Code of Professional
Conduct.

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 Ethics in Endodontics 645

In some countries, dental surgeons have the right to council acts but convey a non-professional message to
advertise their practice within legal limits; however, in the society. Such advertisements, being unethical
India the rules do not permit advertisements. In the damage the professionalism of dentistry and insult the
Dentists (Code of Ethics) Regulations 1976, advertising, social contract that dentistry enjoys by being a
‘whether directly or indirectly, for the purpose of profession and not a business.
obtaining patients or promoting their own professional In spite of the ban on advertising by dental
advantage’, or acquiescing in the publication of notice professionals, there are few who keep on resorting to
directing attention to the operator’s skills, knowledge advertising to promote their professional services.
or qualifications, is considered as unethical, equal to Unethical advertising is neither appreciated nor
conniving at or aiding in any kind of illegal practice. condoned, but there is a demand for relaxation in the
Under the code of ethics, any advertisements by dental restrictions, which would be beneficial for the budding
professionals should be limited to the announcement dental professionals. The majority of young and
of the opening of a practice, a change of address, a budding dental surgeons approve of advertising, while
change of ownership, or the introduction of a new their seniors reject it. This may be a reflection of
partner. Despite these rules, a number of practitioners industry competition, a drop in ethical standards, or a
ignore the code of ethics to advertise their services. greater familiarity with the world of advertising and
Many dental surgeons feel that advertising is a media among younger age groups. The ethical
necessary part of running a business, and a few also objections to advertising by healthcare professionals,
argue that it has the potential to be beneficial. including dental professionals, persist with good cause.
Supporters of advertising claim that information The rise of new technologies and media is another
advertising can empower consumers to make good challenge, but the ethical issue remain the same.
decisions regarding their oral health; increase the
community’s awareness of dental healthcare; encourage Standard of Care
better quality dental services; and help consumers
The standard of care in dental profession is defined as
choose their dental surgeon. However, there are also
the degree of care that a concerned dental surgeon
those who defend the traditional view that dentistry is
would exercise under similar circumstances. The
primarily a health profession and not a business; and
standard has been expressed as the capability/expertise
that the ethical considerations of a profession should
of the operator as compared to other dental surgeons
be given priority. It is also a fact that industry
in the community with similar education and
competition has allowed commercialization of medical
experience. The dental surgeon should be aware of their
profession in general, which risks undermining the
responsibilities and commitment towards their patients.
ethical standing of the profession. The concept of
commercialization is considered inappropriate and Any conduct failing to conform to the standard of
misleading. The opponents object to the increased care constitutes a breach of duty and an element of
emphasis on fee structure, viz. discounts and ‘treatment negligence.
packages’ etc. The dental surgeons are encouraged to The dental surgeon practicing general dentistry are
regard patients as customers, rather than patients in expected to execute standard of care under any circum-
need of help. A few professionals believe that stances.
advertising could have an adverse effect on the image Endodontists are expected to set a higher standard
of the profession in general and no impact on of care as compared to general dental practitioner.
competitive price reduction. The dichotomy between The element of negligence on the part of the dental
the dual role of dental surgeons as a healthcare provider surgeon is looked into by the attorneys (judges), who
and as a business entity is the main impinging factor. analyse whether standard of care was followed or not.
Commercial goals are one side of the coin; whereas, The evidence and justification of standard of care
professional goals are other side of the coin. However, presented to the patient at that given time and
business itself is not unethical, and the reality is: if the circumstances are to be explained to the judge by the
practice fails as a business, the practitioner fails as a dental surgeon.
professional. It is important to comply with the following basic
The issue of poorly designed advertisements is also criteria:
of concern of the ethical principles. Many dental • Complete dental and medical history is to be

39
advertisements can be seen with poor design that lead recorded.
to discredit to the profession. Some of these advertise- • The affected teeth along with other oral tissues
ments may well be within the guidelines of state dental should be thoroughly examined.

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 646 Essentials of Endodontics

• Do not rely on old radiograph, take a new good Guidelines for Referral
quality radiograph; may be more than one at • Is the treatment technically beyond my capability?
different angulations. • Is there a high-risk of complications for the indicated
• Analyze the previous treatment plan and never procedure?
hesitate to suggest more conservative/feasible
• Will the patient feel comfortable if I perform the
options; do not straight away disregard the earlier
procedure?
plan.
• Inform the patient about prognosis of the affected • My experience and confidence with the said
tooth and also possible time span. procedure.
• Refer the patient whenever treatment protocol is The accepted principle is ‘When in doubt, refer to
beyond your control and expertise. some experienced operator’. The dental surgeon should
Advances in technology continue to make dentistry follow certain duties (guidelines) while referring his/
a truly dynamic profession. The standard of care in each her patient to a consultant. The duties are:
and every ailment is improving over the years. Duties towards the patients
For example, the standard of care in the direct place- The duties towards the patients are:
ment of Class II restoration in early eighties differs from
• Dental surgeon has the ethical obligation to furnish
the present standard of care. It requires a commitment
record of the patient to the referral doctor, either free
to continuous learning to offer standard of care of the
level prevalent at any given time. Participating in or accepting nominal fee.
continuing education courses, and professional • A reasonable arrangement for emergency care of a
meetings help updating the knowledge on periodic patient, (may be direct or referred) should be
basis. available in every dental clinic.
The dental surgeons should strive to use current • Dental surgeon shall be obliged to seek consultation,
technology, materials and knowledge to offer the if need be; the referred consultant upon completion
requisite standard of care to their patients. of the treatment shall return the patient to the
referring dental surgeon.
Refer or Not to Refer • Dental surgeons have an obligation to use their
The concept of ‘referral’ has never been properly knowledge and experience for overall improvement
understood and followed in our country. Patients keep of dental health of the society.
on moving from one dental surgeon to another; may
not get satisfaction of their choice. By and large, patients Duties towards the referral doctor (consultant)
are not aware of their problems; and also who is the The duties towards the referral dental surgeon are:
perfect person to solve that problem. The ethics and a. The dental surgeon should exercise control in making
the concept of referral implies certain objectives. comments on oral health of the patient, e.g. for
The common objective is that no patient shall move example, a difference of opinion as regard disease
from one practitioner to another without someone in or treatment should not be communicated to patient
command. Every patient should learn and understand in a manner which may offend him.
the importance of the first dental surgeon visited b. One should never criticize the fellow dental surgeon,
(patient has the right to choose and select the initial especially in front of other patients.
doctor). The following features are considered unethical
In case of referral, the basic ‘headquarter’ remains towards professional colleagues:
with the first operator; the patient is to be sent back • Paying or accepting commissions of referrals.
after the requisite consultation/treatment. General
• Undercutting of charges in order to solicit patients
practitioner refer the patient to a specialist for treatment;
for future.
whereas, one specialist can refer the patient to another
for seeking opinion. The referred operator, after • If planned treatment is beyond the competence of
sincerely analysing, inform his/her opinion to the first the initial dental surgeon; even then the patient is
operator (the relevant fee can be charged). not referred to a consultant.
The decision to make a referral is personal, based on • The patient is not sent back to the previous doctor
after the requisite service of the consultant completes.
39 the individual’s own experience, an honest assessment
of one’s abilities in particular areas and the comfort
level, drawing the line as to where one’s expertise ends.
• The consultant should charge as per advice of the
referred dental surgeon.

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 Ethics in Endodontics 647

Endodontic Referrals
A. Referred from
Doctor’s Name: ________________________________ Contact: ___________
Clinic Address: _________________________________
Patient Name: __________________________________

a. Signs and Symptoms Treatment already performed

• Pain in tooth • Prescribed medicines (also report any allergy/sensitivity to
• Swelling drugs)
b. Radiological findings • Caries excavation
• Apical Radiolucency • Root canal opened (report all root canal separately)
• Periodontal condition • Incision/drainage
• Status of pulp spaces • Mishaps (if any)
• Any abnormal findings
c. Any specific complaint
• Trauma or fracture
B. Referred to
Doctor’s Name: ________________________________ Contact: ___________
Clinic Address: _________________________________
Patient Name: __________________________________
Referred For
• Diagnostic consultation
• Root canal treatment
• Endodontic surgery
• Managing root canal mishaps
• Any specific problem

Referred to Dr. ……………………………

Referred by Dr. …………………………... Signature and Date

Negligence and Malpractice root canal instrument in a canal, which cannot be

Dental negligence is a violation of the standard of care retrieved, the patient should be advised and referred
during dental treatment; an injury caused to the patient appropriately.
as a result of negligent dental treatment. The dental The endodontic negligence, is mainly because of
surgeon is liable to face criminal charges for such failure to carry out proper preoperative assessments
negligence. or devise inappropriate treatment plans, substandard
Any kind of negligence or poor quality dental treat- operative procedures and inadequate information to
ment is considered as dental malpractice. the patient as regard postoperative maintenance phase.
Substandard dental care resulting in the above can In case of legal implications, the lawyer will take a
be due to (i) Clinician not possessing a required detailed statement from the dental surgeon to find out
qualification (ii) Qualified persons perform carelessly exactly what happened during treatment. The lawyers
without professional responsibility. usually seek an independent expert opinion as to
Endodontic treatment procedure is the second whether that particular dental practice was acceptable
highest number of malpractice reported in India. Teeth and whether it caused any harm to the patient.
to be treated endodontically should be evaluated for Depending on that opinion, the lawyers tries to settle
any aberrant morphology/anatomy such as curved the claim off the court’s jurisdiction.
roots, calcified canals, and any other potential Traditionally, dental cases do not get into the courts,
complicating factors. Good preoperative X-rays and use probably because the sums claimed might be less than
of a rubber dam are mandatory. Infections due to
endodontic procedures can be ‘deadly’; mainly because
of their anaerobic nature. If the operator breaks any
the expenses of the courts. There have been a few
exceptions in recent years; most of the cases related to
cosmetic dentistry.
39

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 648 Essentials of Endodontics

The dental surgeons should put sincere efforts to diffuse d. Injuries Leading to Burns
patient dissatisfaction; mostly the patients are not heard Burns can be because of thermal or chemical reasons.
properly and need psychological motivation. Dental
surgeon’s conduct and practice, usually solve most of i. Thermal burns: Thermal burns can occur due to:
the problems. The nucleus is how to deal with the • Over used burs; especially at high speeds
complaint, rather to involve lawyers, etc. • Curing lights and few lasers (less chances)
Failure to provide the standard care to the patients • Insufficiently cooled instruments after sterilization
may have many parameters; main are as follows: • Heated instruments especially during sealing off
gutta-percha during obturation.
a. Failure to Provide Adequate Isolation Care should be taken to avoid these mishaps, such
Failure to use rubber dam while performing an endo- as:
dontic procedure is considered as negligence. Use of • Handpiece should be regularly oiled and maintained.
rubber dam is mandatory as it provides appropriate • New and sharp burs should be used.
safety measures during root canal procedures. • Soft tissues should be properly managed during
It prevents the aspiration, inhalation or ingestion of endodontic procedures.
endodontic instruments and irrigants like sodium • Continuous irrigation should be carried out during
hypochlorite, etc. It also reduces microbial contamina- root canal treatment.
tion and reinfection.
In case the instrument is ingested/aspirated, the ii. Chemical burns: Many strong chemicals, medica-
dental surgeon should: ments and irrigants can cause chemical burns in the
• Inform the patient oral cavity, which can be avoided by:
• Reassure the patient • Proper training of assistants
• Refer patient to medical care • Avoid overuse of chemicals
• Pay all the bills of patient. • Alternate between strong irrigants/acids with
The barrier technique such as sterilized gloves, face normal saline
mask, protective eye shields and disposal of waste, etc. • Avoid carrying chemicals over patient’s face.
should also be followed during endodontic treatment.
e. Negligence in use of Sodium Hypochlorite
b. Failure to record Quality Radiographs Sodium hypochlorite, when extruded beyond tooth
Good quality radiographs are mandatory; if not recorded apex, manifest as combination of severe pain, swelling
properly, will be considered as negligence. Avoid and profuse bleeding both through tooth and
excessive radiation exposure to patient at all expenses. interstitially.
Whenever possible, take digital radiographs, so as Such accidents are managed by aspiration, ice packs,
to incorporate all the affected teeth in least number of analgesics, wound débridement and warm compress
radiographs, coupled with minimum exposing the (after 24 hours).
patient. Following principles help in preventing such
X-ray units and other related armamentarium should accidents:
be checked before use. • Using needles with closed end and lateral vents
• The tip of the needle be 1.0–2.0 mm short of apex if
c. Negligence related to Pain Management open on top
Pain management is mainly carried out by using local • Do not allow binding of needle in root canal
anesthesia in dental set up. Injecting local anesthesia • Do not force irrigants in root canals.
may lead to problems such as:
• Syncope f. Iatrogenic Negligence
• Fracture of needle in site i. Tissue emphysema: Collection of gas or air in the
• Hematoma tissue space of facial planes leads to tissue emphysema.
• Trismus While using air pressure, blast of air should be directed
• Drug allergy at horizontal direction against the walls of tooth and
• Infection (postoperative). not periapically.

39 In few cases, patients have moved consumer courts

with allegations of negligence by the operator.
ii. Overlooking periodontal concerns: In case the
affected tooth has caries progressing subgingivally or

t.me/Dr_Mouayyad_AlbtousH
 Ethics in Endodontics 649

into the furcation area, or if the periradicular area shows The prevention of misconduct in research is best
signs of bone loss/inflammation; the dental surgeon achieved by properly educating all individuals
should seek opinion of a periodontist or other specialist involved in research. It is suggested that researchers
before proceeding to endodontic treatment. should participate in appropriate educational activities,
keeping abreast with the latest knowledge. Constant
iii. Instrument separation: Instrument separation
review of current literature in various national and
usually occurs in routine endodontic practice. A sincere
international journals pertaining to our own branch as
effort to retrieve the instrument or to bypass the separa-
well as parallel branches of dentistry should be carried
ted instrument to negotiate rest of canal is mandatory.
out in routine to be able to innovate ideas for the
If unable to manage the separated instruments, the
betterment of the concerned subject.
guidelines are:
All participating investigators and their colleagues
• Explain the patient about the incident.
conducting any research should follow ethical practice,
• Show the remaining part of the instrument and with due consideration of any local legislation and
assure that the tooth will remain asymptomatic. regulations. Ethical committee approval must be
• Record the methods tried to retrieve or bypass the obtained along with written informed consent by the
separated instrument. participants in their own language.
• Refer the case to someone expert and follow till Where the population is vulnerable to exploitation,
satisfaction of the patient. it is important to respect their human rights and ensure
• Keep the records for any medicolegal reference. that the research has relevance and potential benefit to
iv. Perforations: Perforation is a common procedural their well-being.
accident, mainly due to unpredictable anatomy. The
Human Research
endodontists are usually competent enough to tackle
the situation. In case the perforation is unmanageable, The declaration of Helsinki is a statement of ethical
the case can be referred to the expert operator for principles for research involving human participants; a
management. The patients should also be explained of subject of ethical standards that promote respect for all
the implications of perforations. human participants and protect their health and rights.
Research must adhere to the fundamental principles:
v. Overextensions: Overextensions is a rare procedural respect the needs for autonomy, beneficence, justice,
error; endodontists are mostly aware of the precautions veracity, fidelity, anonymity and nonmaleficence.
to be taken to avoid such mishap. Human research comprises, investigative clinical
There is a controversy regarding what actually research, clinical trials and studies using tissue samples.
constitutes as an ‘overextended obturation’. It is fine if Biogenetics, using stem cells and utilizing tissue banks
the filling is within the tip of the apex; 1.0–2.0 mm require complete transparency in all aspects of
beyond the apex constitute overextension (patient may consenting and confidentiality.
be asymptomatic). Sealer causing paresthesia are
usually not used these days; the problem caused by Animal Research
obturating materials is usual transient and get resolved An investigator using animals in research should
within one week. The case should be followed up understand basic principles of ethics and also contribute
properly. to the improvement of animal health and welfare.
Researchers should sincerely make efforts to protect
ETHICS IN ENDODONTIC RESEARCH misuse of animals.
Research in the dental profession is moving forward Every effort must be made to:
expeditiously. A fairly large amount of research articles • Preferably replace the use of live animals by non-
are being published by Indian authors. Apart from animal alternatives
institutional trust, the authors should adhere to the • Reduce the number of animals used in research to
Code of Ethics in every aspect of research and publica- the minimum mandatory requirement
tions. This is fundamental professional responsibility • Refine the procedures so that the animal’s suffering
and commitment to an ethical pursuit of knowledge. is kept to a minimum during research.
All of us, especially the budding researchers are
Conflicts of Interest
expected to cooperate in the implementation of this
Code. Misconduct casts doubt on the integrity of indivi-
duals and may lead to complications at any stage of life.
Each individual is expected to follow ethical ways to
avoid conflict in terms of decision-making and
39

t.me/Dr_Mouayyad_AlbtousH
 650 Essentials of Endodontics

publication of data. The appearance of a conflict of Any individual, who is involved in any form of
interest, such as the potential for financial and personal misconduct or misuse of ethical principles is expected
gain, can be as damaging as an actual act of conflict of to report the matter to the concerned authorities. Only
interest. Full disclosure of any potential conflict of then the profession will adapt to a state of satisfaction
interest must be made to the investigator’s institution in any field of research, precisely Endodontics.
or to the association as applicable.
The intellectual property rights of all participating Ethics and Esthetics
researchers should be protected (intellectual property The term ‘esthetic dentistry’ has been used to refer to
rights apply to any potential commercial gain, and must the application of tooth colored restoration in either
be agreed at the outset of the project by the investiga- anterior or posterior regions. Such restorations should
tors, their institutions and/or any other external body, function properly maintaining the stomatognathic
such as a sponsoring company). system.
Cosmetic dentistry implies application of restorative
Dissemination of Information techniques purely to remove the appearance while not
Most scientific journals ask authors to make declara- necessarily improving function. These type of restora-
tions at submission about the integrity of their research. tive protocol should not be at the cost of unnecessary
Many journals have experienced plagiarism; the editors tooth reduction.
need to develop policies to minimize the publication It is important to note that we must resist the
of articles containing evidence of scientific misconduct. provocative call of cosmetic gurus to limit your practice
It is expected that authors, representing a body of to esthetics. Cosmetic dentistry should be undertaken
research in a process of publication should: keeping in view the need and analyzing each aspect of
• not inappropriately fragment data into several the procedure.
different publications The dental surgeons are usually attuned to their
• inform sources of funding patient’s esthetic desires and aspirations. Many of them
• adhere to predetermined guidelines regarding order have added the requisite know-how of the subject
of authorship and are willing to help improving patient’s dental
• agree to its submission for review and publication. appearance by using biologically sound and minimally
Appropriate written permission must be obtained destructive means following ethical principles.
to publish any type of image, which should not identify Esthetic problems are generally managed ethically
the participant. following detailed discussions and careful evaluation
Misconduct is the fabrication, falsification, plagiarism, of the various options available (including the ones that
or any other deviation from accepted practices in other disciplines or skills could possibly provide)
proposing, carrying out, or reporting results from coupled with appropriate training and skills.
research. It is the failure to comply with international, Cosmetic dentistry is regarded as just one aspect of
national, local and institutional requirements for decent restorative dentistry. Restorative dentistry has
the protection of researchers, human participants, always been about managing dental disease;
laboratory animals and the public at large. It is also the maintaining function and improving looks as well.
failure to meet other legal requirements governing However, in seeking to do so, the ‘risk-to-reward ratio’
research. must be considered and enough time must be taken to
ethically weigh up the real potential esthetics benefits
Misconduct includes: against the many risks involved; (risks include long-
• Submission of the same article simultaneously to term biologic damage of the tooth tissue or stability,
more than one journal without informing the editors that might be involved in performing such procedures).
concerned.
• Lack of consent by coauthors (coauthorship of an Laws in Dentistry
article indicates that all individuals who have The laws applicable to dental practice are same as those
genuinely participated in research, have full applicable to anyone who provides personal services.
knowledge of, and are in total agreement with, the As a private practitioner, the dental surgeons are
content of the article). governed by tax laws, employment laws and law of

39
• Lack of acknowledgment of financial support. contract. The dental profession is also subject to a special
• Premature release of scientific data prior to presenta- statue, commonly referred to as dental law or dental
tion or publication in a peer-reviewed forum. practice act.

t.me/Dr_Mouayyad_AlbtousH
 Ethics in Endodontics 651

The laws that are applicable under the act are as 4. Chambers DW. A primer on dental ethics: Part I. Knowing
follows: about ethics. J. Am. College of Dentists: 2006; 73:38–46.
• The name under which a dental surgeon conducts 5. Chambers DW. A primer on dental ethics: Part II. Moral
Behaviour. J. Am. College of Dentists: 2007; 74:38–49.
his practice should not be false or misleading in any
respect. 6. Ellen P and Singleton R. Human rights and ethical considera-
tions in oral health research. JCDA: 2008; 74:439–439e.
• The name of the dental surgeon no longer actively
7. Garbin CA, Garbin AJ, Saliba N, de Lima DC and Macedo
associated with the practice may not be used for more AP. Analysis of the ethical aspects of professional confiden-
than one year. tiality in dental practice. J. Appl. Oral Sci.: 2008; 16:75–80.
• A dental surgeon, who by any means of communica- 8. Grady C. Enduring and emerging challenges of informed
tion, announces that he/she is certified or a consent. N. Engl. J. Med.: 2015; 372:855–862.
diplomate in an area of dentistry not recognized by 9. Hayden JE. Digital manipulation in scientific images: some
Dental Council of India, amounts to making a false ethical considerations. J. Biocommun.: 2000; 27:11–19.
or misleading representation to the public. 10. Jeffocoat MK. A well-founded trust: a sever-tier defence
against scientific misconduct. J. Am. Dent. Assoc.: 2002;
Laws that are related to third party payment are: 133:804, 806.
• A dental surgeon who accepts third party payment 11. Kegley JA. Challenges to informed consent. EMBO Rep.:
under a co-payment plan, as payment without 2004; 5:832–836.
disclosing details to the third party is unethical. 12. Macklin R. Understanding informed consent. Acta. Oncol.:
• It is unethical for a dental surgeon to increase the 1999; 38:83–87.
fee to a patient solely because the patient is insured. 13. Main BG and Adair SR. The changing face of informed
• Payments received under a government funded consent. Br. Dent. J.: 2015; 219:325–327.
program or constituent dental society sponsored 14. Nicholl J. The ethics of research ethics committees. BMJ:
2000; 320:1217.
program should not be overbilled.
15. Nichols PS and Winslow GR. How strict is confidence? Gen.
• A dental surgeon who submits a claim form to a third
Dent.: 2004; 52:15–17.
party reporting arbitrary treatment dates so as to
16. Nicol TE. Confidentiality versus disclosure of a patient’s
assist a patient in obtaining benefits under a dental infectious status. Gen. Dent.: 1997; 45:78–80.
plan is unethical. 17. O’Neill O. Some limits of informed consent. J. Med. Ethics:
• A dental surgeon who incorrectly describes a dental 2003; 29:4–7.
procedure in order to receive a greater payment or 18. Phaosavasdi S, Thaneepanichskul S, Tannirandorn Y, Pupong
reimbursement is unethical. V, Uerpairojkit B, Pruksapongs C and Kajanapitak A. The
• A dental surgeon who performs unnecessary dental idealistic ethical doctor. J. Med. Assoc. Thai.: 2007; 90:
procedures is also unethical. 201–202.
We, the dental professionals, should strive to do what 19. Renson CE. Ethical dilemmas in dentistry. Dent. Update:
1994; 21:225–226.
is ‘right’. Usually, it is tempting to do what is easy.
Simeroth’s words clearly explain ‘Science takes us to 20. Shaw D. Ethics, professionalism and fitness to practice: three
concepts, not one. BDJ: 2009; 207:59–62.
the next level, but it is ethics that keeps us there’. Ethical
21. Sikri V and Sikri P. Ethics and endodontic intervention. JIDA:
codes tries to direct the moral consciousness of the
1990; 2:31–33.
members of the profession to a particular situation and
22. Skene L. Undertaking research in other countries: national
are important in developing standards of moral ethico-legal barometers and international ethical consensus
conduct. It is imperative to concentrate doing the right statements. PLoS Med.: 2007; 4:e10.
thing in the right perspective rather than repenting why 23. Smith AJ. Human embryonic stem cell research and its
you did that wrong. regulation. J. Dent. Res.: 2007; 86:197.
24. Smith D. Five principles for research ethics. Am Psychological
BIBLIOGRAPHY association: 2003; 34:56.
25. Sotelo J. Regulation of clinical research sponsored by
1. Angell E, Sutton AJ, Windridge K and Dixon-Woods M. pharmaceutical companies: a proposal. PloS Med.: 2006;
Consistency in decision making by research ethics 3:e306.
committees: a controlled comparison. J. Med. Ethics: 2006;
26. Trathen A and Gullaghor JF. Dental professionalism:
32:662–664.
definitions and debate. BDJ: 2009; 206:249–253.
2. Castledine G. The importance of keeping patient records 27. Zabala-Blanco J, Alconero-Camarero AR, Casaus-Perez M,
secure and confidential. Br. J. Nurs.: 2006; 15:466.
3. Chamber DW. The ethics of experimenting in dental practice.
Dent. Clin. North Am.: 2002; 46:29–44.
Gutierrez-Torre E and Saiz-Fernandez G. Evaluation of
bioethical aspects in health professionals. Enferm Clin.: 2007;
17:56–62.
39

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t.me/Dr_Mouayyad_AlbtousH
 Index
A Antihistamine 32 Bisecting technique 123
Abbott’s classification 53 Anticholinergic 32 Bitewing technique 123
Access cavity preparation 241 Apexification 456, 517 Bite test 113
in difficult cases 254 Apex locators 260 Bleaching
Accessory/lateral canals 202 Apexification/apexogenesis in agents 425
ActiV GP 357 deciduous teeth 517 of teeth 424
Apexogenesis 455 Block of terminal branches 558
Active posts 382
Apical Bluetooth technology apex locator 262
Acupuncture 39
constriction 197 Boiling 189
Acute apical/alveolar abscess 67, 411
control zone 273 Bonding agents 384
Acute apical periodontitis 63
coronal techniques 273 Bone morphogenetic proteins (BMPs) 631
Acute exacerbation of chronic lesion
delta 203 Bone removal 568
(phoenix abscess) 68, 418
extrusion 306 Bone rongeurs and files 568
Acute irreversible pulpitis 410
foramen 199 Boston post 381
Acute periradicular abscess 411
periodontitis 418 Bow technique 238
AD seal 323 scar 74 Broaches and rasps 155
Adaptive type apex locator 263 scouting 273
Adverse effects of bleaching 437 transportation 617 C
Advertising in dentistry 644 tuning 272 C-arm imaging 132
Affected dentin 443 Apicoectomy 574 Calamus 3D system 349
Age changes in pulp-dentin complex 520 AquaPick device 303 Calcibiotic root canal sealer 326
AH26 321 Archaea 93 Calcific degeneration 59
AHPlus 321 Argon laser 544 Calcifying odontogenic cyst 75
Ahmed and Dummer classification 207 Assessing apical constriction area 258 Calcium-enriched mixture 637
Air emphysema 307 Atrophic degeneration 60 Calcium
Aldehydes 309 Autoclave 189 enriched cement 361
All-ceramic post 397 Automated devices 161 hydroxide 309, 325, 447
Alternative analgesics 39 Autotransplantation 578 phosphate-based sealers 330
Ameloblastoma 176 Avulsion 416 phosphate cement 361
Amelogenesis imperfecta 423 Callahan-Johnston technique 342
American Society of
B Canal
Bacterial injuries and pulp diseases 51
Anesthesiologists (ASA) 554 finder system 162
Balanced force technique 276
Anesthetic agents 32 master file 158
Barbed broaches 155
Anesthesia delivery system 33 Cancellier extractor kit 612
Barbiturates 31
Anachoresis 91 Carbamide peroxide 293
Barodontalgia (aerodontalgia) 49
Anesthesia test 114 Capillary condensation method 361
Berman, Blanco and
Anatomy of the root apex 256 Cohen’s classification 464 Carbon fiber post 394
Andreasen’s classification 463 Beneficences 642 Carie-care 445
ANSI 551 Beam splitter 533 Carisolv 286
Anterior palatine nerve block 561 Benzodiazepines 31 Caseation necrosis 61
Antibiotic Binoculars 531 Causes of inter-appointment pain 23
as intracanal medicaments 310 Bioactive glass 293, 310 Causes of pulp diseases 49
in pediatric endodontics 517 Biocalex 316 CBCT imaging 205
prophylaxis 43 Bioceramics 636 Cell homing 633
resistance and virulence associated Biodentine 363 Cementing medium 384
with plasmids 100 Biofilm in endodontic infections 100 Cementoblastoma 76
Antibioma 45 Biolase 543 Cementodentinal junction 197
Anticurvature filing motion 224 Biological/natural scaffolds 631 Cervical resorption 492
Antiemetic drugs 46 Biological width biomimetics 628 Cetrehexidin 293

653

t.me/Dr_Mouayyad_AlbtousH
654 Essentials of Endodontics

C-files 158 pulp 15 Densfil 351

Chelating agents 293 root apex 197 Depressibility 113
Chemical injuries and pulp diseases 51 Computerized Development of dentin-pulp complex 10
Chemically softened gutta-percha 341 local anesthetic administration device 563 Devitalization pulpotomy 507
Chin-Jyh Yeh classification 468 tomography 126 Diagnostician 108
Chisel and osteotome 568 Computer expert system 134 Diaket 316
Chitosan 286 Concussion 416 Digital
Chlorhexidine 292 Condensing osteitis 73 image processing 260
Chlorine dioxide 293 Confidentiality 644 subtraction radiography 125
Chloropercha 324 Cone beam computed tomography 127 Dia proseal 323
Cholesteric liquid crystals 133 Congenital hyperbilirubinemia 423 Dilaceration 226
Chronic apical abscess 69 Conscious sedation 34 Diode laser 545
Chronic hyperplastic pulpitis Conservative access cavity Direct pulp capping 446, 505
(pulp polyp) 58 preparation 246 Disinfection of guttapercha 338
Chronic periradicular inflammation 68 Consequences of avulsion 483 DNA-DNA hybridization 198
Circumferential filing 157 Continuous locking suture 572 Downpack 346
Citric acid 295 Coolidge and Kesel method 259 Double flare technique 278
Clamp first technique 239 Core materials 401 Draping the patient 555
Clark’s classification 473 Coronaflex (crown remover) 608 Dry heat sterilization 190
Clark’s rule 122 Coronal-apical techniques 277 Dry dam 237
Classification of Coronal Drug resistance 45
antibiotics 41 leakage 606 Dual wavelength spectrophotometry 120
cracks 472 scouting 273 Dulbecco’s solution 486
C-shaped canals 200 Corrective surgery 553 Dyes 112
endodontic emergencies 409 Corticosteroids 37
endodontic isthmus 154 Cotton suture 570 E
endodontic-periodontal lesions 589 Cracked tooth syndrome 413, 470 EDTA 293
flaps 565 Crown and root fracture 476 Effect of bleaching on
local anesthetics 557 Crown-down pressureless technique 277 dentin 438
periradicular diseases 64 Crown fracture 475 gingiva and mucosa 438
posts 379 Cryosurgery 581 pulp 439
pulp diseases 52 C-shaped canals 200 restorations 439
root fractures 470 Custom structure of enamel 438
traumatic injuries 462 cast metal posts 380 Effective pain control 35
Cleansing of the cavity 187 fibre post 392 Efficacy of irrigants 299
Clinical protocol for forced extrusion 537 Cvek pulpotomy 452 Electric pulp testing 117
Closure of surgical site 571 Cyanoacrylates 324 Electrochemically activated solution 296
CO2 laser 543 Electronic dental anesthesia 563
D Electrosurgery 509, 580
Code of dental ethics 641
DG 16 154 Element system 345
Coagulative necrosis 61
Decompression of large Ellis classification 463
Coated cones 356
periapical lesion 578 EMLA 564
Cohen’s classification 527
Declination angle 530 Enamel infraction 475
Cold
Dehiscence 180 Endo pulse 162
gutta-percha 338
Endo-Z bur 64
sterilization 189 Dens
Endo access bur 164
test 116 evaginatus 226
Endodontic–orthodontic continuum 597
Combination invaginatus 22
Endodontic–periodontal relationship 588
flap 566 Dentinal hypersensitivity 410
Endodontic
technique of bleaching 435 Dentin/biological posts 398 failures 603
Combined lesions 590 Dentin 10 implant 584
Complications during root canal chips 358 pressure syringe 515
irrigation 305 dysplasia 423 treatment and allergic reactions 86
Components of permeability 13 treatment in elderly 521
dentin 11 shavings 380, 450 working width 266
inflammation 78 Dentinogenesis imperfecta 227 Endoactivator system 302

t.me/Dr_Mouayyad_AlbtousH
 Index 655

Endo extractor system 612 Fiberfill Grades of mobility 113

Endo-eze system 162 obturation system 359 Grasping instruments 608
Endoflas 319, 326 post 398 Greater taper files 166
Endomethasone 319 Fiberoptic transillumination 115 Grossman
Endo sequence system 171 Fiber posts 392 classification 589
EndoREZ 357 Fibrous degeneration 60 method 259
Endoscope 529 Figure of ‘8’ suture 573 sealer 317
Endosolv E 614 Files 156 Growth factors 630
Endosolv R 614 Filing motion 271 Guedes-Pinto paste 515
Endotec 346 Fillippi’s classification 463 Guided tissue regeneration 576
Endocrown 403 Fissured fracture 462 Gut/catgut 569
Endovac system 304 Fistulative surgery 553 Guttacore system 354
Endowave system 175 Flaming 189 GuttaFlow 353
Endo-Z Bur 610 Flex master 175 Gutta-percha 337
Enrique Basrani classification 468 Flex-R file 158
Enterococcus faecalis 103 Flexoreamer 156 H
Envelope flap 566 Flexofiles 157 Hanging gutta-percha 606
Enzymes 449 Flexidam 237 HEBP 295
Enzyme cleaner 188 Fluorosis 422 Hemostatic agents 508
Epiphany 323, 614 Flute 150 Halides 309
Epistemology 640 Focal infection theory 86 Hand scrub 555
Er:YAG laser 544 Formocresol pulpotomy 508 Handidam 237
Ergonomics 529 Fracture of Hard laser 543
Essential oils 308 alveolar process 487 Healing of
Established failure 603 Ni-Ti instruments 153 root fracture 481
Ethylene oxide (ETO) sterilization 191 Frequency type apex locator 262 sinus tract 86
Etiology of pulpal diseases 441 Full thickness flap 565 Heat
Ethical dilemmas 641 Furcation canals 202 carriers 143
Ethics in Fusion and gemination 226 softened gutta-percha 342
endodontics 640 Future of endodontics 7 test 116
endodontics research 649 Hedstrom files 157
esthetics 650 G Heithersay and morile classification 468
Evolution of Gallium-aluminium-arsenide (GaAIAs) Helix angle 153
endodontics 1 diode laser 545 Hemisection/bicuspidization/
Ni-Ti instruments 152 Garcia Godoy classification 463 radisectomy 579
Exploring instruments 154 Garcia Godoy method 573 Herbal irrigants 298
Extirpating instruments 155 Gary-Carr technique 612 Hero 642 170
External resorption 491 Gates glidden drills 165 Higa bridge remover 608
Extra-radicular infections 94 Gene High restoration 409
Extrinsic discoloration 423 therapy 628 Hippocratic oath 641
Extrusive luxation 416 transfer system 99 History of ethics 641
Eukaryocytes 96 Genetic engineering 628 Home bleaching 430
Eyeless needles 570 Geriatric endodontics 520 Host-microbe interaction 99
Eyepiece 531 Giant cell granuloma 76 Horizontal
EZ-Fill system 356, 359 Gingival dam 425 dimensions of root canals 205
Girobroaches 161 root fracture 476
F Girofiles 161 Hot
F 360 files 184 Giromatic 161 gutta-percha test 117
Factors affecting Glass salt sterilizer 189
instrument removal 610 bead sterilizer 190 Hughes probeye camera 133
post retention 383 fiber post 395 Hybrid technique 169
selection of posts 382 Gloving 555 Hydrogen
Fan’s classification 201 Glutaraldehyde 508 peroxide 292
Fast dam 237 Golden mediums 159 peroxide toxicity 437
Ferrule effect 389 Gow-gates technique 562 Hydron 322

t.me/Dr_Mouayyad_AlbtousH
656 Essentials of Endodontics

Hyflex X-file 176 Iodophors 293 LN bur 164

Hyperaemia of pulp 53, 410 Iodoform paste 326, 515 Local
Hyper-reactive pulpalgia 410 Irradiated polyglactin 569 anesthesia 555
Hyperparathyroidism 228 Irreversible pulpitis 56 infiltration 558
Irrigation needles 306 Long buccal nerve block 562
I lrrivac needle pressure system 305 Loomba’s classification 465
Idiopathic root resorption 498 Lutein method 203
Illumination 532 J Loupes 527
JW 117 154
Immunocompetent cells 15 Luebke’s classification 472
Jiffy tube 515
Immunological methods 95 Luxation injuries 416, 482
Johnson-Callahan method 324
Impedance type apex locator 261
Justice 644
Implant M
material and design 585 McSpadden compactor 347
K
placement 587 K3 body shapers 170 Make of endodontic instruments 151
Impression of the prepared post space 387 K3 files 170 Magnetic resonance imaging 127
Incisive nerve block 563 Kerr pulp canal sealer 316 Magnification 530
Inclinable binocular 531 K-flex files 158 changers of 531
Incomplete pulp tissue removal 418 Kline crown remover 608 Maillefer guttacondenser 347
Indicators for sterilization 193 Kloroperka N-O sealer 324 Maisto paste 515
Indirect pulp Kooldam 237 Maleic acid 294
capping 443, 504 KRI paste 515 Management of
treatment 504 Knot tying 571 canal blockage 615
Infected dentin 443 KY pliers 608 canal transportation 616
Inflammation 78 failures 606
Inflammatory events leading to L fear and anxiety 30
inter-appointment pain 24 Land 153 ledge 616
Infrared thermography 34 Laser Management of
Inferior alveolar nerve block 561, 562 assisted bleaching 435 missed canals 615
Informed consent 643 optical disc storage 134 pain 35
Infraorbital block (anterior and middle delivery system 540 patient with dental trauma 473
superior alveolar nerves) 559 device 539 perforation 617
Incomplete tooth fracture 390 Doppler flowmetry 119 soft tissue injuries 474
Ingle’s method 259 emission modes 540 Mandibular nerve block 562
In-office bleaching 426 hazards 551 Masserann kit 612
Irrigating techniques 301 safety 552 Mattress suture 572
Isthmus 203 sterilization 192 Maxillary nerve block 558
Instidam 237 tissue interaction 541 Max-i probe 301
Interstitial fluid pressure 16 Lateral Mechanical injuries and pulp diseases 49
Instrument removal system 612 compaction method 338 Mechanisms of revascularization 634
Isolite 238 luxation 416 Meisinger meitrac instrument system 612
Integra-post system 381 Laws in dentistry 650 Melton classification 200
Interaction among micro-organisms 99 Law of Mental nerve block 562
Inter-appointment endodontic pain 22 cemento-enamel junction 196 MetaSeal 323
Intermediate size files 159 centrality 196 Metalift crown remover 608
Internalized discoloration 423 color change 196 Methods of suturing 572
Internal resorption 496 concentricity 196 Microabrasion assisted bleaching 429
Interrupted suture 572 symmetry 196 Microbes in endodontic disease 90
lntracanal Laws of orifice location 196 Microbial
aspiration technique 305 Ledging 616 diagnostic techniques 95
medicaments 308 Lentulo spiral 160, 515 interactions in infected root canals 99
lntraligamentary technique 559 Liberators 174 Micro-debrider 155
lntrapulpal technique 559 Light speed (LSX) system 168 Microflora of root filled teeth 93
Intrinsic discoloration 422 Light transmitting post 399 Micro-opener 155
Intrusive luxation 416 Lingual nerve block 562 Microbrush 284
Inverted point technique 340 Liquefactive necrosis 61 MICR 498

t.me/Dr_Mouayyad_AlbtousH
 Index 657

Mid-treatment emergencies 418 Odontogenic Phases of access cavity preparation 243

Mineral trioxide aggregate 358, 360, 363, 458 keratocyst 75 Phenol based agents 308
Missed canals 615 pain 1 Phoenix abscess (mid-treatment
Mobility and depressibility 113 One shape single rotary file 179 flare up) 418
Modified Open mouth approach for Photobiological interactions 541
McSpadden 347 inferior alveolar nerve block 561 Photodynamic therapy 297
step-back technique 276 Opioid analgesic 36 Photochemical interactions 541
walking bleach technique 434 Optical reflection vitalometer (ORV) 120 Photon induced photoacoustic streaming
Monoblock concept 320 (PIPS) technology 548
Optradam 237
Photoplethysmography 121
Morphogens 628 Orabase paste 425
Photothermal interactions 541
Molecular methods 95 Oral sedation 34
Phytomedicines 311
Mountain pass concept 21 Orascope 529
Plasma sterilization 191
M-series pluggers 160 Orthodontic extrusion 600 Plasmids in the oral/
MTAD 295 Ossifying fibroma 76 endodontic microbiota 100
MTwo 175 Osseous entry 574 Plastic endo 176
Munce discovery bur 164 Over the counter products 437 Platelet rich plasma (PRP) 632
Mynol cement 319 Oxidative potential water 296 Polyethylene fiber 376
Myofascial pain 27 Ozonated water 297 Polyglactin 910 (vicryl) 569
Myxoma 76 Postcore restorations 378
P Post diameter 384
N PAC-160 350 Post-endodontic pain 25, 250
NSAIDs 36
Palpation 112 Post inlay 399
N2 sealer 319
Palatal developmental groove 227 Posterior superior alveolar block 560
N2-sargenti technique 360
Papa-carie 444 Post length 383
Nano care plus 298
Parachute technique 608 Post taper 393
Nanotechnology 8
Parkell parallel post 381 Post-treatment emergencies 420
Nasopalatine nerve block 561 Potential failure 603
Parallel posts 381
Nathoo’s classification 423 Power bleaching 427
Paraperiosteal technique 558
NaviTip 302 Pow-R files 176
Partial
NaviTip Fx 302 Pre-endodontic pain 19
pulpectomy 510
Nd:YAG laser 544 Pre-fabricated metal posts 380
pulpotomy 452
Needles with eye 571 Premedication 32, 555
thickness flap 566
Neo Ni-Ti 184 Preoperative assessment 554
Parts of the microscope 530
Nerve Preparation of
Passive posts 380
block 556 canal space 385
Paste fillers 160
impulses in pulp 16 surgeon and patient for surgery 555
Pastes as obturating materials 360
Ni-Ti superflex 302 surgical site 555
Patency filing 272
Nogenol sealer 318 Polymerase chain reaction 96
Path finder files 59, 155
Non-odontogenic pain 26 Preservation pulpotomy 508
Pedicle flap 567
Non-pedicle flap 568 Presurgical
PEEK 403
Non-maleficence 642 evaluations 555
Peeso Reamers 165
Negligence and malpractice 647 preparation 555
Percussion 112
Non-narcotic analgesics 35 Pre-treatment emergencies 410
Percussive instruments 608 Principle of laser 539
Nonsurgical retreatment 605
Perforation repair 579, 618 Principles of
Non-thermocatalytic bleaching 427
Periapical surgical incisions 565
Non-vital
cyst 72 suturing 571
pulpotomy 510
cemental dysplasia 76 Prinz’s classification 64
tooth bleaching 432
granuloma 70 Procosol-silver cement 316
Nygaard-Ostby method 324
Pericoronitis 26 Procedure scope 528
Nylon 570
Periodontal probing 113 Profile system 166
O Periradicular Prokaryocytes 96
Objective lens 532 curettage 574 ProTaper
Obtura II 348 diseases of endodontic origin 66 gold 184
Ocular injuries 481 lesions of non-endodontic origin 74 next 180
Octenidine 293 lesions 21, 66 system 166

t.me/Dr_Mouayyad_AlbtousH
658 Essentials of Endodontics

PRS system kit 612 Resinifying Smooth broach 154

Pruden’s classification 473 agent 622 Sodium hypochlorite 291
Pulp 14 therapy 621 Soft laser 542
curettage 450, 506 Resistance type apex locator 261 Solvidont 295
necrosis 20, 60 Respiratory rate of the pulpal cells 597 SOAP 110
polyp 58 Retrograde filling materials 361 Sonic irrigation 302
protection 446 Revascularization 634 Soymilk 486
Reversible pulpitis 55 SPAD 319
therapy 443, 504
Riebler’s paste 319 Spinal tap needle 612
vitality tests 115
Rigid body shapers (RBS) 176 Spinas and Altana’s classification 464
Pulpal
Risk factors for developing flare-up 24 Splint fibers 396
degeneration 50
Roeko seal 324 Split cast metal post 399
inflammation 49
Role of lasers in endodontics 545 Spreader dryer 160
Pulp-dentin complex regeneration 16 Spreaders and pluggers 159
Root canal
Pulpectomy 510 Standardized technique 273
curvatures 203
Pulpitis 55 Standardization of endodontic
preparation 270
Pulpotomy 454, 506 instruments 150
sealers 314
Pulse oximetry 120 Stem cell 629
Root-end preparation 575
Step-back technique 273
Root fracture 415, 465
Q Step-down technique 277
QMix 292 Root resorption 489
Sterilization of
Quantec system 170 Rubber dam application 238
dental unit waterlines 192
Quartz fiber post 395 Rules for access cavity preparation 242
handpiece 192
Quickfill compactor 348 instruments 187
S miscellaneous instruments 193
R S-file 158
Steroids 37
RaCe 171 Salvizol 295
Stieglitz forceps 609
R-file 158 Sankin apatite root canal sealer 330
Stock classification 291
Radiovisiography (RVG) 123, 259 Scaffold 631
Storage medium 485
Radix entomolaris and Schanker’s design 303
Straight binocular 536
radix paramolaris 199 Schnider’s method 203
Stressed pulp 441
Rake angle 153 Sealapex 325 Structure of dentin-pulp complex 9
Rationale of case selection in Sealer plus 322 Subluxation 416
endodontics 139 Sectional gutta-percha 358 Successful 350
Rare endodontic infections 92 Sedative-hypnotic drugs 30 Sure-flex file 159
Rasp 155 Self-adjusting files 180, 305 Surface texture 384
Reamers 156 Semilunar flap 567 Surgical
Reaming motion 271 Sequence of access cavity preparation 243 armamentarium 573
RealSeal 355 Series 29 159
Reciprocating instruments 161 bur 568
Side effects of vital bleaching 437 endodontics 553
ReciProc system 183
Silk suture 569 needles 570
Referred pain 22
Sikri’s classification 291 principles and techniques 564
Regeneration 627
Silica fiber post 395 procedures 574
pulpotomy 509
Silver cones 351 Suture
Relaxed flaps 566
SimpliFill obturation system 359 materials 569
Relief 153
Removal of Simon’s classification 589 removal 573
crown and bridges 608 Single visit selection 570
gutta-percha 384, 614 endodontics 366 Sword post puller 550
separated instruments 610 pulpectomy 506 Syngcuk Kim’s hypothetic model 81
silver points 614 Sinus tracing 123 System B 344
post and core 609 Smart seal 356
Repair following endodontic treatment 94 Smart bleaching 436 T
Replacement resorption 424 Smear Tagger’s classification 291
Replantation 417, 578 clear 386 Tailor-made gutta-percha/roll-cone
Resilon 354 layer 281 technique 341
Resin based sealers 320 layer and smear plugs 14 Talim and Gohil’s classification 473

t.me/Dr_Mouayyad_AlbtousH
 Index 659

Talon cusp (eagle’s talon) 226 Triple-flex files 159 W

Tapered posts 380, 382 Trushape 3D conforming files 184 Wach’s sealer 318
Taurodontism 227 True cell-inductive agents 439 Walking bleach technique 434
Technique of anesthesia 34 Tubli-seal 307 Walkoff paste 515
Test cavity 114 Tuberculin syringe 515 Walton’s classification 291
Tests assessing supply of blood 118 Twisted files 183 Wamkey crown remover 608
Test measuring tooth temperature 133 Two-sided/triangular flap 567 Watch winding motion 271
Tetraclean 296 Types of Warm vertical condensation 342
Tetracycline staining 423 lasers 542 Washer disinfector 188
Thermafil 350 scaffold 631 Watch-winding motion 271
TheraCal LC 450
U Wave one 181
Thermal injuries and pulpal diseases 50
U-file 158 Wedjet 236
Thermal
Ultrafil system 349 Weine’s classification
remover 385
Ultra-flex file 159 endodontic–periodontal lesions 590
test 116
Ultrasonic root canal anatomy 205
Thermapact 347
cleaners 188 Weine’s method 203
Thermocatalytic bleaching 426
imaging 133 Whaledent parapost 381
Thermocompaction 347
instruments 162 WHO classification 64
Thermomechanical remover 385
irrigation 303 William Kahler’s classification 473
Three-sided/trapezoidal flap 567
plasticizing gutta-percha 348 Williams’ classification 473
Tissue
Ultrasound imaging 133 Wing technique 238
changes following inflammation 81
Unifile (S-file) 158 Working
emphysema 648
engineering 628 length 256
V
Titanium rotary files 176 Variable taper 174 width 266
Tooth Vascularity of pulp 16 Wound closure 569
bleaching with non-thermal Vazirani-Akinosi inferior alveolar Wynman crown gripper 608
atmospheric plasma 436 nerve block 562
discoloration and staining 462 Venting 406 X
fracture 462 Veracity 644 Xeroradiography 125
restorability index (TRI) 374 Vertical Xtreme reamer with
Touch ‘N’ heat 344 condensation 343 rapid safe shaping 176
Transient inflammatory resorption root fracture 415 XP-endofinisher 284
(surface resorption) 495 Vertucci classification 206
Transillumination 115 Vibratory devices 161 Z
Transmetal bur 165 Vibringe system 303 Zinc oxide eugenol 316, 362, 514
Transverse root fracture 415 Videography 115 Zipperer thermocompactor 347
Traumatic bone cyst 75 Virus 93 Zone of
Treatment planning in endodontics 139 Vista-probe irrigating tips 302 contamination 82
Trephination 25 Vital apical pulp cells 634 infection 82
Trifecta system 351 Vital pulp therapy 442 irritation 82
Trigeminal neuralgia 27 Vital tooth bleaching 424 stimulation 83
Trident crown remover 608 Vitapex 514 Weil 15
Triple antibiotic paste 458 Vortex-blue 184 Zurich technique 169

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