J Indian Prosthodont Soc (July-Sept 2013) 13(3):165–174

DOI 10.1007/s13191-012-0181-2

REVIEW ARTICLE

Digitization and Its Futuristic Approach in Prosthodontics

Ritika Bhambhani • Jayanta Bhattacharya •

Saibal Kr. Sen

Received: 26 November 2010 / Accepted: 27 September 2012 / Published online: 7 October 2012
 Indian Prosthodontic Society 2012

Abstract Digitization has become part and parcel of the robotic devices would be performing the restorations under
contemporary prosthodontics with the probability of most the command and surveillance of the master—the dentist
of the procedures being based on the digital techniques in without his immediate presence.
near future. Let us think of X-rays or photographs, making
impressions, recording jaw movements or fabricating Keywords Digitisation
Digital technology

prosthesis, educating and training new dentists or patient Virtual dentistry
Recent/contemporary prosthodontics
motivation for practice build up, all has become digital.
CAD-CAM has revolutionized not just the ceramic tech-
nology but has also been used for the CAD-CAM implant Introduction
surgeries, maxillofacial prosthesis and diagnostic splints.
Today a practicing dentist needs to be abreast with the Background
latest but with the technology changing so fast, this poses a
great challenge. There is endless scope of digitisation and Dentistry can be dated back to eighteenth century, when
technology in prosthodontics- let it be in the clinical and impressions meant use of waxes and plaster of Paris [66];
lab procedures like use of CAD-CAM technology, stere- and the dental equipment consisted of hand driven and later
olithography, rapid prototyping, use of virtual articulators water driven motors. From then there’s been a long journey
and digital face bows, digital radiographs, or in the field of to achieve the contemporary paraphernalia [22, 26, 72].
training, education and research by the use of virtual Along with limited materials and equipment there were
patient programs, dental softwares, optoelectronic record- selective treatment options but, with the passing years and
ing of jaw motion, digital instron machine, retention testing the endless growth in research, emerged a gamut of options
device, audiovisual aids,… the list will remain endless. The in dentistry. The contemporary dental practice has endless
article reviews those various aspects of prosthodontics options for preserving oral health and provides next to
where digitization has modified the conventional proce- natural aesthetics with an enhanced approach, reduced
dures. For discussion they have been considered under the treatment time, minimized error potential and better quality
educational aspect, diagnostics, treatment procedures, assurance. These reasons rightly explain present day den-
prosthesis fabrication and lastly the research and futuristic tistry being called the Golden Age of Dentistry [75].
development. The day is not far when remote sensing Evolution of CAD-CAM ceramics could make single sit-
ting restorative dentistry a reality in the 21st Century [33].
This has been possible by the visionary approach of great
R. Bhambhani
J. Bhattacharya
S. Kr. Sen
Department of Prosthodontics, Gurunanak Institute of Dental researchers, scientists and practitioners.
Sciences and Research, Kolkata 700114, India Digitization started to influence dental fraternity with the
form of audio-visual aids in both teaching and patient
R. Bhambhani (&)
education. It was in 1980s that advances in computerisation,
27E/5, Baburam Ghosh Road, Tollygunge, Kolkata 700040,
India optics, miniaturisation and laser technologies enabled cap-
e-mail: ritikabhambhani@yahoo.co.uk ture of dental impressions [66]. Even digital radiography

123
166 J Indian Prosthodont Soc (July-Sept 2013) 13(3):165–174

was used widely in medicine, but it was only in the 1980s, procedures, training of students, patient motivation, practice
that the first intra-oral sensors were developed for use in management and not the least dental research. It tends to be a
dentistry. The early systems could not capture panoramic narration of influences of digitisation on prothodontic
and cephalometric images, and this made it impossible for practice, teaching and research. With technology evolving
surgeries to abandon film processing and adopt digital so fast dentist needs to be abreast with these developments.
technology [51]. The development of cost-effective intra-
and extra-oral digital technology coupled with an increase
in computerization of practices has made digital imaging a Methods
superior alternative in many respects to conventional film
imaging. Early 1980s also paved the way for computer- Search Strategy
aided design/computer-aided manufacturing (CAD/CAM)
technology. CAD-CAM initially was used for enabling Electronic search was conducted for online journals to
design in aircraft and automotive industries; it was first search for relevant articles and material with selected
patented in dentistry by Dr. Duret (1984). Since then, the keywords like digitisation in dentistry, digital technology,
technology has evolved in two directions—the intraopera- CAD-CAM, virtual technology, recent developments, dig-
tory application for single appointment restoration (using ital radiographs, contemporary practice etc. The various
prefabricated ceramic monoblocks) and paralleled by, sites scanned were—MEDLINE/Pubmed journals and
CAD/CAM systems for commercial production centres and Cochrane reviews. Handsearching was done for articles in
dental laboratories [34, 43, 50, 66]. the following journals—Journal of Prosthetic dentistry,
The research and development in material science and Dental clinics of North America, Journal of American
the related paraphernalia cater to preservation of oral dental association, Journal of Indian Prosthodontic society,
structures with an early diagnosis, repair of dental disease to Journal of Prosthodontics, Journal of contemporary dental
achieve aesthetics and function with high level of predict- practice, Journal dental research and Dental Practice.
ability and even less number of sittings. Digital technology Bibliographies of the selected articles were referred for
has immense influence over the clinical aspect, laboratory relevant papers. Grey literature was included from journals
procedures, training of students, patient motivation, prac- and online publications, World Wide Web, online confer-
tice management and not the least dental research. Today a ence proceedings and reports etc. All search included rel-
dentist has ample of options to choose from but needs to be evant articles uptill 2012.
abreast with the developing technology to avail them all.
With the mounting research it is quite challenging to keep Selection Criteria
pace with it but is the need of the hour. More updated the
knowledge, better we provide to our patients and hence The authors independently assessed the relevant papers for
helping towards the upliftment of dental fraternity. inclusion; any disagreements were resolved by discussion.
Selection included literature suggesting use of digital
Need of Review techniques in areas of dentistry like clinical, laboratory
steps, training, patient motivation or research. Articles with
Digitisation, being so significant in the dental practice pros and cons of various techniques and futuristic opinion
needs to be understood well. There are a few systematic regarding them were preferred.
reviews found regarding the effect of fast growing digital
technology in prosthodontics. The array of developments Data Collection and Analysis
need to be known, as they either affect the contemporary
practice or may have a significant futuristic outcome, and A comprehensive search for the relevant studies was car-
hence give an endless scope on revision. Such reviews ried on health related electronic bibliographic databases, a
would help the dental fraternity to be refreshed with the narrative synthesis was conducted. Articles were searched
latest, and cultivate a futuristic vision. and screened according to the inclusion criteria.

Objective
Results
Review has been written with a contemporary reference
considering the pros and cons of various technological The literature regarding recent techniques helps us assim-
progresses. The impact of digital technology in prostho- ilate latest trends for benefit of patient and expansion of
dontics is immense, hence for ease its influence has been dental profession as a whole. The transition from old to
considered under sections—the clinical aspect, laboratory new occurs with basic aim of making patients life better,

123
J Indian Prosthodont Soc (July-Sept 2013) 13(3):165–174 167

and also providing a convenient practice for dentists. To allows the dental surgeon to simulate true life situations in
achieve the above it is needed to explore all options, it’s patients [21, 23, 25, 26, 41]. The term ‘Digitisation’ refers
with use and time that the drawbacks and limitations of to conversion of an image or signal into digital code by
newer materials and methods would surface. To utilise scanning, tracing, or a graphics tablet or using an analogue
technology in its best form it needs to be gripped well. to digital conversion device. It is a process of making a
Digitisation is quite an immense subject and current review digital copy or recording of something that was originally
has further scope of elaboration in each of its aspects. analogue; which might be a document, artefact, sound,
performance or natural phenomena. There is endless scope
AID in Clinical Practice of digitisation and technology in prosthodontics—starting
from motivating a patient and maintaining records to
Digital technology has impact over the patient motivation, making digital impressions, use of digital radiographs and
practice management and clinical treatment procedures. Be photographs, use of virtual articulators and digital face
it digital radiographs aiding in diagnosis, CAD-CAM bows for planning and fabrication of prosthesis; or for
ceramics for better aesthetics and function with less num- processing of restorations with use of CADCAM technol-
ber of appointments, rapid prototyping and stereolithogra- ogy, stereolithography, rapid prototyping etc. The appli-
phy for maxillofacial prosthesis fabrication and still others cations of above are becoming essential in field of training,
provide high level of predictability, more convenience and education and research akin to clinical practice. Research
even less number of sittings. has been enhanced by utilising virtual patient programs,
dental softwares; digital recording of jaw motion, FEA and
AID to Research digital instron machine etc.… the list will remain endless.
This review has been an attempt to elaborate some of the
Research has to be kept on for better dental productivity. Be significant points of above. This technological influence
it development of material science, or the latest equipment over the dental service if used wisely would make practice
or enhanced treatment techniques…all owe to continued more convenient for both dentist and the patient.
research. Old methods undoubtedly form the basis of
research science but have been enhanced upon by digital Role of Digitization for Patient Motivation and Practice
methods. One being, the incorporation of digitisation in the Management
Finite element analysis (FEA) by use of computerised or
software based models. FEA is based on force and dis- Building a good rapport with the patient and educating
placement relationships for analysis and design of large and him/her regarding their poor oral health and need for pro-
complex structures. It incorporates a computer model of a fessional help, can be assisted using intraoral camera,
material or design that can be stressed and endured to dif- education softwares, videos, 2D and 3D images of dental
fering amount and direction of force and the effect ana- procedures. This helps them understand the interrelation-
lyzed. This has found place in research to analyze the ship of teeth with general health, and also wade away
stresses transferred by various materials, their mechanical dental fear. Softwares like XCPT, Dentrix and Bite FX can
properties, effect of different designs on dentofacial struc- be used for a better understanding of treatment plans por-
tures, implant loading and their placement and other endless trayed in a visually convincing way [8, 21, 38]. Such
options [15, 53, 55, 69]. softwares digitize analogue radiographs or capture any
Web based surveys based been retrospective studies digital radiograph (panoramic, periapical or CT scan) and
provide an enormous subject research method over a global give the dentist the ability to annotate the image and to
platform [52, 61]. Other areas where digitisation has helped place a variety of objects, crowns, implants, abutments and
in research is use of digital instron machine for material bone grafts to explain to the patient exactly what the doctor
testing, retention testing devices, use of softwares for sees. They can be well termed as an on-the-spot consul-
anthropometric, cephalometric and esthetical ratio studies. tation tool, to build trust and save time because the patient
immediately grasps the ideas being presented. Similar
softwares have been in use in orthodontics to design the
Discussion treatment plan on a computer and generate 3D virtual
treatment course to represent teeth movements to an ideal
Digitization has captured the world with its ubiquitous position (Invisalign-ClinCheckTM software). Hence the
applications, such that no field remains aloof. If casually treatment results can be visualized in a three dimensional
said, anything and everything is just a click away…. The form and help motivate a patient better [64].
future of dental practice is closely linked to the utilization Literature suggests use of internet based programs for
of computer-based technology and virtual reality, which educating patients about tobacco cessation. Basis of such

123
168 J Indian Prosthodont Soc (July-Sept 2013) 13(3):165–174

interventions are the estimated figures of 1.73 billion Coral draw and Adobe Photoshop allow evaluation of
internet users worldwide and expected to increase further. photographs for anthropometric and tooth ratios [20, 64].
These internet based interventions were found to be highly Laser digitisation of casts was done using 3D optical dig-
cost effective with an easy access from home, public itising technology and evaluated for accuracy to see the
libraries and other internet points. But mixed results were effect of tray selection and cast formation technique. The
found, not consistent depending on effect of face to face method hence paved way for accurate techniques of cast’s
interaction on patient psychology [14]. measurements as an alternative to manual measurements
The computerized data base technology has decreased [5]. Digital machines have also been an aid in measuring
the problem of limited storage space for patient records as certain parameters which are otherwise difficult to analyse
even the plaster casts can be converted to virtual 3D study quantitatively. This has been done with an aim of
models. Conferencing and communication amongst the increasing reliability and validity of research example use
functioning team has become easier with the newer com- of a digital device to check retention of lower dentures.
munication methods. Same can be applied to direct retainers etc. [2].
Material testing has become more efficient with better
Role of Digitization for Training and Research testing methods like digital Instron machine. INSTRON is
a contraction of the words ‘‘instrument’’ and ‘‘electronics’’
The education and training of dental students has also and represented an important milestone in the materials’
become more effectual and practical with audiovisual aids, testing machine, since 1946 when its use was established in
which aid for better presentation of the subject. Learning Canton. Rockwell tester was marketed over 80 years ago
through the World Wide Web, and visualizing many dental and later developments involved micro-indentation testers,
related videos on You-tube is just a click away for today’s Knoop and Vickers testing, Brale diamond indenter, Bri-
generation. One big leap in field of education is with virtual nell portable tester etc. many of which found use in dental
softwares like Virtual dental patient (CANDIDETM, research. Shore Instruments, developed durometer which
PERIOSLIMTM) that allow learning with the true feel of could be used for measuring the hardness of plastics, rub-
working on a patient. Surgical training has traditionally bers and elastomers. From pencil style and analogue
been one of apprenticeship, where the surgical trainee durometer, manual operating stands and rubber test blocks,
learns to perform surgery under the supervision of a trained today they have revolutionised to S1 digital durometer with
surgeon. This is time consuming costly, and of variable interchangeable probes. Similarly there has been develop-
effectiveness. Training using a virtual reality simulator is ment in impact testing machines; all these improved testing
an option to supplement standard training and assessing the machines hence allow a better and accurate understanding
competency of a surgeon in an ethical way [27, 29, 46]. of material properties.
These systems have been applied in the medical fraternity Finite element analysis is based on force and displace-
for learning laparoscopic procedures, diathermy and other ment relationships for analysis and design of large and
surgeries; use of virtual drilling systems would similarly complex structures. It incorporates a computer model of a
aid dental students in getting acquainted with tooth anat- material or design that can be stressed and endured to
omy, handling of drilling instruments and other challenges differing amount and direction of force and the effect
associated with drilling procedure. This can prove to be analyzed. This has found place in research to analyze the
beneficial for teaching restorative procedures, tooth prep- stresses transferred by various materials, their mechanical
aration, sutures, implant related surgeries and others, with properties, effect of different designs on dentofacial
the feel of working on a patient without harm or any risk to structures, implant loading and their placement and other
patient [62, 73] Others have also expressed this to be endless options [15, 53, 56, 69].
inferior to traditional methods of teaching due to lack of
patient interaction [27]. The other quite a significant use of Role of Digitization in Diagnosis and Treatment
virtual technology is use of virtual articulators discussed Planning
later.
Research forms backbone for development of dentistry A good treatment begins with the right diagnosis, and the
as a professional science. Computers and various softwares dental X rays have been an important diagnostic aid from
have been an aid in studies. Scores of web based studies the start. Investigators have stated digitized radiography to
and surveys have been listed in literature [52, 61]. These be superior to the traditional radiograph in disclosing the
have been retrospective studies or opinion based researches defects affecting hard tooth tissue (dental caries) [31, 51].
and provide enhanced subject research methods on a global The computerized digital sensitivity allows for the use of
platform. These surveys were found to be 38 % less on cost up to 1024 gray levels, thus it enables the operator to
compared to traditional mail surveys [54]. Softwares like distinguish the earliest changes that could affect the hard

123
J Indian Prosthodont Soc (July-Sept 2013) 13(3):165–174 169

tissues especially in areas of low contrast e.g. detection of (2) gradient coil technology for more rapid image acqui-
incipient caries at the inter-proximal areas. Digital radi- sition leading to the possibility of true cine magnetic res-
ography offers immediate viewing of images which is onance; and (3) smaller, more powerful computers for
highly desirable during implant procedures, post placement more rapid data processing have implications over ana-
and patient education. It omits the use and maintenance of tomic and physiologic assessments of the joint along with
chemicals and dark rooms. Images can be enhanced using reduced costs [28, 30, 39].
the intuitive software for easier reading and diagnosis, Diagnostic imaging is an essential component of implant
comparison and subsequent viewing. The storage and treatment planning, and a variety of advanced imaging
electronic distribution of digital images allows better modalities have been recommended to assist the dentist in
communication with other practitioners and third-party assessing potential sites for implants. Developments in
benefit companies and not to forget the decreased radiation cross-sectional imaging techniques such as spiral tomog-
exposure by fewer retakes (no processing errors). 3D raphy and reformatted computerized tomograms have
radiographs have been called the fourth dimension of become increasingly popular in the preoperative assess-
endodontic treatment planning as they improve the preop- ment and planning for dental implant. Radiographs are
erative visibility of lateral canals, presence/absence of used to evaluate bone quantity, quality, density and aes-
additional canals and knowing all possible about the given thetic site assessment for implant placement. Digital pan-
tooth anatomy before any invasive procedure [3, 6, 9, 44]. oramic imaging being one of the earliest and most sought
On the other hand, software related barriers need to be after, as it is a non-invasive procedure. Authors suggest
overcome for use of computers in dental radiography; the considering risk–benefit analysis before applying newer
alteration of an image to remove artefacts or scratches imaging methods e.g. radiation exposure etc. which also
needs to be documented and cannot be relied on as an makes the latter most used [18, 58].
evidence in the legal sense [49]. Its high cost also does not Dental photography has always been an aid for patient
encourage many of the practitioners; however, some newly education and aesthetic treatment planning. Intuitive soft-
introduced equipment with a reasonable price have aided in wares make it possible to visualise post treatment effect,
a transition from traditional to computerized radiography. variation of tooth size and form etc. It is utilised for many
Radiovisiography (RVG) is a multi-component system web based studies to survey opinions of dentists and non
advocated by Dr Francis Mouyen in 1989 [47], which dentist population [52, 61]. Photographic records are easier
enables the operator to capture colored images from the to store, can be viewed at various angulations and easily
patient mouth via an intra—oral camera and the transfer of measured. Regular photographic records, at all dental visits
this image to the computer. The images on a computer can could be great help to examine the age changes like
be zoomed, rotated, cut or edited; or further manipulated- occlusal vertical dimension, tooth colour and facial chan-
enhancement, contrast stretching and reversing. The newer ges. This can redefine practice of prosthodontics with their
versions of intra-oral cameras are very light in weight (less ability of visual communication and medicolegal docu-
than 50 g) and the illumination for image capture is no mentation for contemporary practice. Use of digital pho-
longer a fibre-optic which is affected by aging but it tographs has also been explored in areas of maxillofacial
became light emitting diodes which give adequate white restoration to replicate the iris for fabricating a custom
illumination to comply with darkness inside the mouth. ocular prosthesis for an anopthalmic patient and restoring
Radiation exposure is reduced with RVG when compared other maxillofacial defects like mandibulectomy [1, 8].
to conventional radiography; a Cone beam CT further helps Softwares like Adobe Photoshop and Coral Draw allow
in reduction of radiation exposure by nearly 10 to 30 times potential for the digital subtraction photography, which
less than that of a conventional CT radiograph. improves detection of caries, periapical lesions, bone
Advent of digital radiography has enhanced the study of changes, periapical healing following an endodontic treat-
temperomandibular joint- its functioning, pathophysiology ment as early as 2 months [7].
and disorders. Other than the conventional plain film Diagnosing and treating occlusal errors has never been
modalities, array of contemporary options available for easy. To analyze the problems arising from occlusal origin
TMJ imaging are—CT with cone-beam technology, MRI constitute a great difficulty due to the complex nature of
and nuclear imaging including single-photon emission the human occlusal system. An atraumatic dental occlusion
computed tomography and positron emission tomography. is the area of growing demand in the fields of restorative
These advancements improve the understanding of this and reconstructive dentistry [40, 59]. Systems like Tekscan
complex joint and its pathology, ultimately leading to (T scan) and Matscan permit a precise study of occlusal
improved treatment outcomes. Refinement in magnetic contacts and the forces created; examining even slightest of
resonance technology like (1) use of new alloys for lighter occlusal interferences, significant in full mouth rehabilita-
weight permanent magnets with reduced operating costs; tion and implant protected occlusion (IPO). It was in 1988,

123
170 J Indian Prosthodont Soc (July-Sept 2013) 13(3):165–174

Dr William Maness [42] working in Tufts introduced his task. These omit the use of materials and their related
automated computerized sensor for analysis of the dental inaccuracies; this historical development of impressions
occlusion. Aim was to register the patient occlusion on a has been aptly called Bites to Bytes [66] Digital recording
thin patented 60 microns thickness disposable sensor to allows multiple uses without loss of accuracy; omit need of
record instantaneously the patient bite in terms of location, disinfection and could be beneficial in patients with
timing and force of every tooth in contact. This record is hypersensitive palate. Advent of digital impressions has
transferred to a computing system which can make an aided in further shortening the chairside time for CAD –
actual simulation of the patient occlusion on a monitor, CAM restorations [10–12].
assuming the different situations possible during centric, But as with any other digital technology, the technique
eccentric and functional movements. This provides both sensitivity increases; inadequate tooth preparation or
qualitative and quantitative assessment of occlusion. The insufficient soft-tissue management cannot be compensated
system was termed T scan, and got accepted well due to its for. Sufficient gingival displacement is required for good
advantages like simple operation, dynamic viewing of emergence profile, or egression silhouette as scanning
occlusion, timed analysis of force during various positions through gingival tissue is not possible. 3D optical digitising
of teeth contact and the possibility of permanent docu- technology allows 3D images to be scanned with a 3D
mentation and monitoring of the occlusal condition after scanner and these can be coupled with computerised
carrying on the various treatment protocols. It not only milling machines for processing restorations. The scanning
presented a valuable method for clinical evaluation and method differs in various systems, regarding the distance to
understanding of the occlusal problems but also an be kept from tooth; kind of light used or need of powdering
important tool for teaching purposes. There have been the surface to be scanned. The E4D scanner has a separate
many improvements in the system (up to 4th generation) scanning and milling unit with automated interunit com-
now allowing use of a 100 microns thin sensor and soft- munication, its scanner utilises a red light laser (20,000
ware to analyze and display the timing and force of the cycles per second) to create a 3D model. The ICEvery-
patients bite in 2D and 3D graphics. thingTM (ICE) feature of the system’s DentalogicTM soft-
Akin to occlusion knowing details of mandibular motion ware takes pictures of teeth and gingiva before and after
and TMJ also pose a challenge. Their detailed observation tooth preparation with occlusal registration. The 3D ICE
may form a basis for diagnosing musculoskeletal disorders view makes margin detection easier. CEREC AC gives
of the jaws, to monitor progress or evaluate prosthodontic dentists the choice of implementing in office fabrication or
treatment functional results. Various electronic, telemetric sending the digital images with CEREC CONNECT
methods, magnetometry and optoelectronic methods aid in directly to the laboratory, where the restoration can either
above. Mandibular kinematics permits detection and be milled directly or a model can be created for traditional
assessment of TMJ functional irregularities due to internal fabrication of the restoration. Its scanner operates using
obstacles such as a displaced articular disc. Jaw tracking visible blue light (LEDs) with shorter wavelengths than
devices (K6 Diagnostics) would be helpful in studying jaw previous CEREC models, hence increasing the accuracy of
movements and hence occlusion which may be a micro- the scan. Image acquisition is more rapid with CEREC AC
trauma for temporomandibular disorder [36, 45]. The ele- than with previous models due to the continuous capturing
vated muscle activity associated with malocclusion of a series of images by the scanner once in position. The
directed nocioception can be detected with surface elec- system software has been designed to verify the digital
tromyography (EMG). An EMG device named BITE preparation and interocclusal clearance followed by which
STRIPTM can record muscle activity for 6 h which pro- a digital version of the proposed restoration is created prior
vides useful information in nocturnal bruxism. All these to its fabrication. The CEREC MC XL milling centre can
techniques mainly revolve around the aim of studying be used to create full contour crowns in six minutes. Other
stomatognathic system, as accurately and precisely possi- systems used for chairside digital impression is Lava
ble. Computerized pantographs like Cyberhoby articulator C
O.S., iTero scanner; the latter utilizes parallel confocal
can be used for restoration of deteriorated dentitions, imaging to capture a 3D digital impression of the tooth
thereby relating the stomatognathic system near to surface, contours and gingival structure. Parallel light
accurate. emission from the scanner, does not need to be held a set
distance from the tooth and will also scan when touching
Role of Digitisation in Treatment and Associated the teeth, enables the detection of angled contours. As
Laboratory AID mentioned another difference between the various systems
is the requirement for powdering. The CEREC system
Impression making is an indispensible part of prostho- requires a coating of reflective powder on the dry prepa-
dontics, and digital impressions have revolutionised this ration prior to scanning. Light powdering is required when

123
J Indian Prosthodont Soc (July-Sept 2013) 13(3):165–174 171

using the Lava C.O.S. system. The iTero system does not through the soft tissue. Bone contour data are registered
require powdering. The optical impressions and other over the computerized tomographic image. Guided by
digital records can be much needed information for the treatment preplanning software, a chairside robotic
functioning of forensic dentistry [33, 34, 57] Digital manipulator fabricates guiding sleeves that direct the drill
impressions with LAVATM Oral Chairside Scanner have and implant during the osteotomy and implant placement,
been used for assessment of gingival contour and compared respectively [63, 64]. Construction of CAD/CAM bilateral
with traditional clinical indices like modified gingival ear prostheses has been described using laser scanning of
index and bleeding index [48]. the defective regions of a patient’s face and rapid proto-
Another area of digital application has been shade rep- typing using 3D anatomic models from digital ear library.
lication, and this has always been prone for inter and intra The accuracy of the photographic 3D imaging system
operator variability. Visual shade matching is now being has been found accurate for clinical description of the mid-
overrun with methods like photography, colorimeters and face structures and may be potentially useful for rapid
spectrophotometers (Shade Match, Shade Vision, Shade prototyping of facial prostheses [35].
Eye and Clear Match) which give more consistent shade Advances in computer technology enable cost effective
and a near life effect with colour mapping of tooth selected. production of individual pieces. Further research is needed
Digital imaging and shade matching decrease the inter- to utilize this technology for veneering, which would not
operator and intra-operator variability; and also eases the just decrease manual error but also processing time. The
communication with the laboratory [4, 32]. CAM component is expected to undergo a remarkable
The accuracy and precision in planning and early change towards adaptation of high speed machining to
diagnosis also allows use of approaches like microrotary permit faster removal of material. This would reduce
instrumentation, air abrasion and laser technology with machining time and could reduce the production costs.
bonded resin based composite restorations [19]. Another important technological application is use of
Along with clinical procedures even the production virtual articulators. Treating occlusion and restoring oral
stages have become automated; with the cutting edge health needs a good articulator simulating the oral envi-
technology of CAD-CAM or conoscopic system (Strau- ronment, there has been immense development in design of
mann, LAVA, CEREC-CAD-CAM scanners, software and articulators so as they can closely simulate the mouth,
ceramic material). CAD/CAM systems have three func- Bernard Frank said ‘‘Mouth is the best articulator’’ con-
tional components: data capture unit or scanner, CAD to sidering limitations of the existing articulators. Application
design the restoration and CAM to fabricate the restoration. of virtual technology to articulator design aims to repro-
The precision scanning technique, intuitive design software duce close to real life situation; the virtual articulator has
and industrial manufacturing machines decrease the labo- been designed for the exhaustive analysis of static and
ratory deficiencies of the restoration and has made possible dynamic occlusion, with the purpose of substituting
the use of zirconium based ceramics (which otherwise is mechanical articulators and avoiding their errors. It can
difficult to machine), hence resulting in excellent high simulate the specific masticatory movement of the patient,
quality metal free dental prosthesis. CAD was initially and the program calculates the sites where the opposing
based on ‘‘subtractive method’’, but the recent processes teeth come into contact during mandibular animation.
involve ‘‘additive’’ approaches like rapid prototyping and Mechanical articulators are different from the real life
selective laser sintering technologies or a combination of biological setting; they cannot simulate masticatory
additive and subtractive CAM [33, 37, 50]. The latter movements that are dependent upon the muscle patterns
decreases material wastage. It not just finds place in area of and resilience of the soft tissues and joint disc. Moreover,
ceramic veneers, crowns, inlays, onlays but also posts, tooth mobility cannot be simulated by plaster models; as a
occlusal splints or surgical splints for implant planning, and result, the latter are unable to reproduce the real life
even in fabrication of maxillofacial prosthesis [13, 16]. dynamic conditions of occlusion. And a passing mention to
CAD-CAM aided implant surgeries aid in proper planning other limitations derived from the procedures and materials
and execution of treatment and result in biomechanically used for assembling the models in the articulator: precision
sound prosthesis, implementing minimally invasive flap- in orienting the model, expansion and contraction of the
less procedure [13, 63]. Tactile registration based Implant plaster, deformation of the bite registration material, the
locating System has been proposed to be simple method for stability of the articulator, etc. [24, 41]. Use of virtual
accurate implant design and placement, requiring only technology has been mentioned as used for studying
basic computer experience, minimal operational space, and occlusion on mounted patients casts [17].
low infrastructure investment [60]. Computer-assisted To analyse a situation on virtual articulator the plaster
surgery help to improve oral implant planning and the models need to be scanned with a scanner, CT scan or 3D
intraoral bone-sounding device maps the surface of the jaw imaging over which prosthesis is then statically modelled

123
172 J Indian Prosthodont Soc (July-Sept 2013) 13(3):165–174

and later the excursive movements are simulated using a it digital radiographs aiding in diagnosis, CAD-CAM
CAD system (or ultrasound or optoelectronic methods) ceramics for better aesthetics and function with less num-
analyzing occlusal collisions to adequate/modify the ber of appointments, rapid prototyping and stereolithogra-
design. The basic system of the virtual articulator generates phy for maxillofacial prosthesis fabrication and still others
an animation of the movements of the mandible based on provide high level of predictability, more convenience and
the input data, and calculates the points of occlusion, which even less number of sittings.
in turn are shown on-screen by means of some type of
code. Digitised dental arches have been studied using vir- Implications on Research
tual articulator of Kordass and Gaertner, Szentpétery’s
virtual dental articulator and needs more research; a digital Research has to be kept on for better dental productivity.
face-bow is another aspect of this project which allows for Be it development of material science, or the latest
a more precise location of the occlusal surface. equipment or enhanced treatment techniques…all owe to
continued research. Digitisation permits many newer and
Future Scope of Digitisation effective methods of research.
But the major hindrance in acceptance of the recent
The pace at which Digitization is conquering dental prac- technology is the associated costs. Dedicated and timeless
tice will revolutionise the future of dentistry. Research in research continues to develop hardware and software so as
areas like Optical coherence tomography (D4D Technolo- to make these technologies in reach of the practitioners.
gies) and would allow creating a sliced image of the tooth Also the training and continued education is needed to
or other structures. It could be used for potential caries adapt to newer technology. If used well, this would not just
diagnosis, tooth crack location, CAD/CAM imaging, sub- redefine the way dentistry is practiced but help to provide
gingival margin location, periodontal diagnosis, soft tissue better treatment results, and achieve the utmost for the
analysis, and more. Presently digital impressions are profession.
extremely sensitive to face movements which make it There is much scope of detailed discussion on every
difficult to scan preparations intaorally. The newer devel- aspect of this review, and to be applied in contemporary
opments are expected to give more consistent results. The practice there’s a need that the practitioner stays abreast
Evolution 4D system, currently under development by with the latest. And to end with a note, that the endeavour
D4D Technologies (Richardson, Texas), is expected to is to take Prosthodontics to greater heights.
have intraoral data capture capabilities. Other commer-
cially available CAD/CAM systems capture data from Acknowledgments Warm thanks to Dr Santanu Sen Roy (Senior
lecturer, Department of community and public health dentistry,
models, using mechanical or optical digitizers of various GNIDSR.) for his thoughtful comments, advice and help for design-
types. With few exceptions, these high-precision digitizers ing the search strategy.
use technologies that prevent them from being used in-
traorally. The complete edentulous arches if recorded Conflict of interest None known.
digitally can be treated without the discrepancy of REA-
LEFF factor. Other areas to be explored include use of
virtual articulators and digital face bows to facilitate References
automatic design of the occlusal surface.

Authors’ Conclusion Included Studies

1. Artopoulou II, Montgomery PC, Wesley PJ, Lemon JC (2006)

Advances in digital imaging, computer aided design, Digital imaging in the fabrication of ocular prostheses. J Prosthet
internet communication, digital manufacturing and new Dent 95(4):327–330
materials have undoubtedly simplified the diagnostic pro- 2. Badra H, Radi A, Aboulela A (2010) The Effect of ultra-suction
cess and improved treatment outcomes. Patient care and system on the retention of mandibular complete denture. Egypt
Dent J 56:101–109
communication can be enhanced substantially by using 3. Brennan J (2002) An introduction to digital radiography in den-
several new technologies. tistry. J orthod 29(1):66–69
4. Brewer JD, Wee A, Seghi R (2004) Advances in colour matching.
Implications on Clinical Practice Dent clin N Am 48(2):341–358
5. Brosky ME, Pesun IJ, Lowder PD, Delong R, Hodges JS (2002)
Laser digitisation of casts to determine the effect of tray selection
Digital technology has impact over the patient motivation, and cast formation technique on accuracy. J Prosthet dent
practice management and clinical treatment procedures. Be 87(2):204–209

123
J Indian Prosthodont Soc (July-Sept 2013) 13(3):165–174 173

6. Buchanan LS (2010) Endodontic treatment planning in the fourth 29. Gurusamy KS, Aggarwal R, Palanivelu L, Davidson BR (2009)
dimension. Dent Today 29(10):104,106,108 passim Virtual reality training for surgical trainees in laparoscopic sur-
7. Carvalho FB, Goncalves M, Tonamaru Filho M (2007) Evalua- gery (review). Cochrane database Syst Rev (1):CD006575. doi:
tion of chronic periapical lesions by digital subtraction radiog- 10.1002/14651858.CD006575.pub2
raphy by using adobe photoshop CS: a technical report. J Endod 30. Guttenberg S (2008) Oral and maxillofacial pathology in three
33(4):493–497 dimensions. Dent Clin North Am 52(4):843–873
8. Chew MT, Koh CH, Sandham A, Wong HB (2008) Subjective 31. Jackson PH, Dickson GC, Birnie DJ (1985) Digital image pro-
evaluation of accuracy of video imaging prediction, following cessing of cephalometric radiographs: a preliminary report. Br J
orthognathic surgery in Chinese patients. J Oral Maxillofac Surg Orthod 13:122–132
66(2):291–296 32. Jarad FD, Albadri SS, Mair LH (2008) The use of objective
9. Child PJ, Christensen GJ (2010) Digital radiography: an digital matching to achieve an esthetic composite restoration.
Improvement. Dent Today 29(8):100–102 J Clin Dent 19(1):9–13
10. Christensen GJ (2009) Impressions are changing: deciding on 33. Kaur I, Datta K (2006) CEREC—the power of technology.
conventional, digital or digital plus in-office milling. J Am Dent J Indian Prosthodont Soc 6:115–119
Assoc 140(10):1301–1304 34. Kelly JR, Benetti P (2011) Ceramic materials in dentistry: his-
11. Christensen GJ (2008) Will digital impressions eliminate the torical evolution and current practice. Aust Dent J 56(Suppl
current problems with conventional impressions? J Am Dent 1):84–96
Assoc 139(6):761–763 35. Kimoto K, Garrett NR (2007) Evaluation of a 3D digital photo-
12. Christensen GJ (2008) Challenge to conventional impressions. graphic imaging system of the human face. J Oral Rehabil
J Am Dent Assoc 139(3):347–349 34(3):201–205
13. Ciocca L, De Crescenzio F, Fantini M, Persiani F, Scotti R (2011) 36. Kinuta S et al (2005) Measurement of masticatory movement by
Computer aided design and manufacturing construction of a a new jaw tracking device using a home digital cam recorder.
surgical template for craniofacial implant positioning to support a Dent Matter J 24(4):661–666
definitive nasal prosthesis. Clin Oral Implant res 22(8):850–856 37. Lee JW, Fang JJ, Chang LR, Yu CK (2007) Mandibular defect
14. Civljak M, Sheikh A, Stead LF, Car J (2010) Internet based reconstruction with the help of the mirror imaging coupled with
interventions for smoking cessation (review). Cochrane Database laser stereolithographic modelling technique. J Formos Med
Syst Rev (9):CD007078. doi:10.1002/14651858.CD007078.pub3 Assoc 106(3):244–258
15. Clelland NL, Lee JK, Bimbenet OC, Gilat A (1993) Use of an 38. Levine LN (2006) XCPT (Accept) software: the future of case-
axisymmetric finite element method to compare maxillary bone analysis and patient acceptance of treatment planning. Dent im-
variables for a loaded implant. J Prosthodont 2:183–186 plantol update 17(4):25–29
16. Dayalan M, Jairaj A, Nagaraj KR, Savadi RC (2010) An evalu- 39. Lewis E, Dowlick MF, Abramowicz S, Reeder SL (2008) Con-
ation of fracture strength of zirconium oxide posts fabricated temporary imaging of temporomandibular joint. Dent Clin N Am
using CAD-CAM technology compared with prefabricated glass 52(4):875–890
fibre posts. J Indian Prosthodont Soc 10(4):213–218 40. Lund J (2001) Occlusion: the ‘‘Science-Based’’ approach. J Can
17. Delong R, Ko CC, Anderson GC, Hodges JS, Douglas WH Dent Assoc 67:84
(2002) Comparing maximum intercuspal contacts of virtual 41. Maestre-Ferrı́n L, Romero-Millán J, Peñarrocha-Oltra D, Peñar-
dental patients and mounted dental casts. J Prosthet Dent 88: rocha-Diago M (2012) Virtual articulator for the analysis of
622–630 dental occlusion: an update. Med Oral Patol Oral Cir Bucal
18. Elian N, Ehrlich B, Jalbout ZN, Classi AJ, Cho SC, Kamer AR 17(1):e160–e163
et al (2007) Advanced concepts in implant dentistry: creating the 42. Maness W (1988) Automated sensor takes clean bites. Dent
aesthetic site foundation. Dent Clin N Am 51:547–563 Today 7:19–22
19. Fasbinder DJ (2010) Digital dentistry: innovation for restorative 43. Miyazaki T, Hotta Y (2011) CAD/CAM systems available for the
treatment. Compend Contin Educ Dent 31(4):2–11 fabrication of crown and bridge restorations. Aust Dent J
20. Fayyad M, Jamani KD, Aqrabawi J (2006) Geometric and 56(Suppl 1):97–106
mathematical proportions and their relations to maxillary anterior 44. Miles DA (2008) The future of dental and maxillofacial imaging.
teeth. J Contemp Dent Pract 7(5):062–070 Den Clin N Am 52(4):917–928
21. Feuerstein P (2004) Can technology help dentists deliver better 45. Mohl ND, Mocall WD, Lund JP, Piesh O (1990) Devices for
patient care? J Am Dent Assoc 135(Suppl):11S–16S diagnosis and treatment of temperomandibular joint disorders.
22. Feuerstein P (2001) How dental practitioners can benefit from the Part I. J Prosthet Dent 63(2):198–201
internet. J Mass Dent Soc 50(2):14–17 46. Moorthy K, Munz Y, Jiwanji M, Bann S, Chang A, Darzi A
23. Feuerstein P (2012) Paul Feuerstein discusses the newest trends (2004) Validity and reliability of a virtual reality upper gastro-
in technology for 2012. Dent today 31(1):17 intestinal simulator and cross validation using structured assess-
24. Gärtner C, Kordass B (2003) The virtual articulator: development ment of individual performance with video playback. Surg
and evaluation. Int J Comput Dent 6:11–24 Endosc 18(2):328–333
25. Gutmann JL (2009) The maturation of science within dentistry: 47. Mouyen F, Lodter JP (1989) Presentation and physical evaluation
the impact of critical milestones and visionary leaders on con- of radiovisiography. Oral Surg Oral Med Oral Pathol 68(2):
temporary achievements. J Hist Dent 57(3):109–122 238–242
26. Gutmann JL (2009) The evolution of America’s scientific 48. Newby EE, Bordass A, Kleber C, Milleman K et al (2011)
advancements in dentistry in the past 150 years. J Am Dent Quantification of gingival contour and volume from digital
Assoc 140(Suppl 1):8S–15S impressions as a novel method for assessing gingival health. Int
27. Gerson LB, Van Dam J (2003) A prospective randomised trial Dent J 61(Suppl 3):4–12. doi:10.1111/j.1875-595X.2011.00043.x
comparing a virtual reality simulator to bedside teaching for 49. Pickens RD (1986) Management of digital image data raises
training in sigmoidoscopy. Endoscopy 35(7):569–575 sticky legal issues. Diag Imaging 8:150–152
28. Gossi DB, Gallo LM, Bahr E, Palla S (2004) Dynamic intraar- 50. Rekow ED, Silva N, Coelho PG, Zhang Y, Guess P, Thompson
ticular space variation in clicking temporomandibular joints. VP (2011) Performance of dental ceramics: challenges for
J Dent Res 83(6):480–484 improvements. J Dent Res 90(8):937–952

123
174 J Indian Prosthodont Soc (July-Sept 2013) 13(3):165–174

51. Richardson A (1981) A comparison of traditional and comput- 67. Higgins JPT, Green S (2006) Cochrane Handbook for Systematic
erized methods of cephalometric analysis. Eur J Orthod 3:15–20 Reviews of Interventions 4.2.6 [updated September 2006].
52. Rosenstiel SF (2004) Dentists’ molar restoration choices and http://www.cochrane.org/resources/handbook/hbook.htm. Acces-
longevity: a web based survey. J Prosthet Dent 91(4):363–367 sed 30 June 2012
53. Sakaguchi RL, Borgersen SE (1993) Non linear finite element 68. Dawson PE (2007) Functional occlusion. From TMJ to smile
contact analysis of dental implant components. Int J Oral Max- design. Mosby, St. Louis, pp 379–392
illoac Implant 8(6):655–661 69. Geng J, Yan W, Xu W (2008) Application of the finite element
54. Schleyer TK (2000) Methods for design and administration of method in implant dentistry. Springer, Berlin, pp 3–6
web based surveys. J Am Med Inform Assoc 7(4):426–429 70. Hobo S, Ichda E, Garcia LT (1989) Osseointegration and occlusal
55. Sevimay M, Turhan F, Kilicarsalan MA, Eskitascioglu G (2005a) rehabilitation. Quintessence publishing, Hanover Park
Three dimensional finite element analysis of the effect of dif- 71. Hobo S, Takayama H (1997) Oral rehabilitation. Clinical deter-
ferent bone quality on stress distribution in an implant supported mination of occlusion. Quintessence Publishing Co, Illinois
crown. J Prosthet Dent 93(3):227–234 72. Reinitz JR (2007) From plaster to polyvinyls: a review of
56. Sevimay M, Usumez A, Eskitascioglu G (2005b) Influence of impression materials. http://www.dentalcompare.com/dentist_
various occlusal materials on stresses transferred to implant profile.asp?expertid=11&headerid=36 Accessed 29 Nov 2007
supported prostheses and supporting bone: a three dimensional 73. Marras I, Papelentiou L, Nikolaides N, Lyrocidia K, Pitas I
finite element study. J Biomed Mater Res B Appl Biomater 73(1): (2006) Virtual dental patient. In: International conference on
140–147 multimedia and expo. pp 665–668
57. Strub JR, Rekow ED, Witkowski S (2006) Computer aided 74. Solaberrieta E, Etxaniz O, Minguez R, Muniozguren J, Arias A
design and fabrication of dental restoration: current systems and (2009) Design of a virtual articulator for the simulation and
future possibilities. J Am Dent Assoc 137(9):1289–1296 analysis of mandibular movements in Dental CAD CAM, Cran-
58. Sukumaran A, Al-Ghamdi HS (2007) A method of gauging dental field university press, Cranfield
radiographs during treatment planning for dental implants. 75. Schmitt SM (2009) Dental digital diagnosis and treatment: new
J Contemp Dent Pract 8(6):82–88 tools for predictable. http://smile.uthscsa.edu/fallSchmittjan/html.
59. Szentpétery A (1997) Computer aided dynamic correction of Accessed 20 July 2012
digitized occlusal surfaces. J Gnathol 16:53–60 76. T scan III system computerized analysis of dental occlusion.
60. Tal H, Schicho KA, Shohat M (2007) Implant locating and www.tekscan.com/dental.html. Accessed 25 July 2012
placement based on a novel tactile imaging and registration
concept: a technical note. Int J Oral Maxillofac Implants 22(6):
1007–1011
61. Wagner IV, Carlsson GE, Ekstrand K, Odman P, Schneider N
(1996) A web based comparative study of assessment of dental Excluded Studies
appearance by dentists, dental technicians and laymen using
computer-aided image manipulation. J Esthet dent 8(5):199–205 77. Hayashi M, Yeung A (2003) Ceramic inlays for restoring pos-
62. Weaver IM, Lu M, McCloskey KL, Herndon ES, Tanaka W terior teeth. Cochrane Database Syst Rev (1):CD003450. doi:
(2009) Digital multimedia instruction enhances teaching oral and 10.1002?14651858.CD003450
maxillofacial suturing. J Calif Dent Assoc 37(12):859–862 78. Lu DP, Lu GP, Lu W (2007) Anxiety control of dental patients by
63. Widmann G, Bale RJ (2006) Accuracy in computer aided implant clinical combination of acupuncture, Bi-digital O ring test and
surgery—a review. Int J Oral Maxillofac Implants 21(2):305–313 eye movement desensitisation with sedation, via submucosal
64. Wong NK, Kassim AA, Foong KW (2005) Analysis of esthetic route. Acupunct Electrother Res 32(1–2):15–30
smiles by using computer vision techniques. Am J Orthod 79. White DJ (2007) Effect of stannous fluoride dentifrice on plaque
Dentofacial Orthop 128(3):404–411 formation and removal: a digital plaque imaging study. J Clin
65. Wong NY, Huffer-Charchut H, Sarment DP (2007) Computer- Dent 18(1):21–24
aided design/computer-aided manufacturing surgical guidance for
placement of dental implants: case report. Implant Dent 16(2):
123–130

Additional References (textbooks, world wide web)

66. Birnbaum NS, Aaronson HB (2008) Dental impressions using 3D

digital scanners: virtual becomes reality. Compend Contin Educ
Dent 29(8):494–505

123