EXTERNAL ROOT
RESORPTION
PRESENTED BY: DR JAMAL AHAD
PGR OPERATIVE & ENDODONTICS
RESORPTION
DEFINTION:
Dental resorption is defined as the loss of dental hard tissues as a result of
clastic activities
Root resorption in the primary dentition is a physiologic process except if it
occurs prematurely.
resorption of permanent dentition is a pathologic process that, if left
untreated, may result in premature loss of the affected teeth.
CLASSIFICATION:
Depending on its location in relation to root surface, root resorption may be
• External root resorption.
• Internal root resorption.
External inflammatory resorption
• External inflammatory resorption (EIR) affects the root's outer surface and is
usually a consequence of dental luxation and avulsion injuries.
• It is a progressive condition with a potentially precipitous onset, capable of
advancing rapidly, such that an entire root surface may be resorbed within a
few months if the tooth is left untreated.
• It also affects teeth diagnosed with chronic periapical periodontitis
Prevalence
• After luxation injuries, EIR ranges from almost 5% to 18%.
• It affects 30% of replanted avulsed teeth. EIR is the most common form of
external resorption root resorption after luxation and avulsion injuries.
ETIOLOGY
• Traumatic dental injuries (e.g., intrusion, lateral luxation, and avulsion) and
subsequent replantation often result in contusion injuries to the PDL.
• Orthodontic Treatment
• Infection and Inflammation
• Pulpitis or Pulp Necrosis
• Impacted teeth
PATHOGENESIS OF EXTERNAL
INFLAMMATORY RESORPTION
The pathogenesis of EIR can be explained as follows.
Contusion injuries to the PDL, after a traumatic dental injury (TDI) involving
the periodontal structures, initiate wound healing, during which osteoclasts
and macrophages are attracted to the site of the injury to remove the
damaged tissue. The initial injury causes a breach in the integrity of the
protective precementum. This permits odontoclasts to bind to and resorb the
underlying mineralized cementum and dentine.
CLINICAL FEATURES
• The tooth in question will not respond to sensibility testing
• In advanced cases may be associated with signs of pulpitis or apical
periodontitis
• discoloration, sinus tract, and/or tenderness to percussion and/or palpation
may be evident
RADIOGRAPHIC FEATURES
diagnosis of EIR is based solely on radiographic examination.
Conventional intraoral radiographic imaging is currently the clinical reference
standard for the detection of ERR after luxation and avulsion injuries.
EIR is characterized radiographically by radiolucent, concave, and sometimes
ragged bowl-shaped excavations along the root surface, Complete loss of the
lamina dura is seen in the area of the resorption.
Management
• Root canal treatment can stop resorption and prevent further progression, aiding in
hard tissue repair of the damaged root surface.
• Initiating root canal treatment upon identifying radiographic signs of External
Inflammatory Resorption (EIR) is crucial.
• Exception: For replanted teeth with closed apices, root canal treatment should occur 7
to 10 days after replantation, regardless of radiographic signs of EIR.
• Early diagnosis and treatment improve the prognosis for the affected tooth,
preventing potential tooth loss.
• Effective chemomechanical debridement of the root canal space is vital for successful
treatment and halting EIR.
• The specific root canal protocol used is less relevant as long as it meets biological
objectives.
• Long-term use of calcium hydroxide in the root canal for established EIR may be
beneficial but should be used cautiously due to the risk of root fracture.
Follow-up and prognosis of external
inflammatory resorption
• - Healing of External Inflammatory Resorption (EIR) seen on X-rays involves:
• - Stoppage of the resorption process.
• - Disappearance of dark areas in nearby bone.
• - Restoration of the space around the root.
• - Untreated EIR can rapidly destroy an entire root within 3 months.
• - Prognosis is particularly poor for untreated immature teeth undergoing EIR.
External cervical resorption
• - External Cervical Resorption (ECR) mainly occurs in the tooth's cervical
region and can invade root dentin in various directions and extents.
• - Typically starts just below the tooth's epithelial attachment, usually in the
cervical region of healthy teeth with normal periodontal attachment.
• - Also known by other names such as invasive cervical resorption,
supraosseous extracanal invasive resorption, peripheral inflammatory root
resorption, and subepithelial external root resorption.
Etiology
o Orthodontics is the most common appearing factor
o trauma
o parafunctional habits
o poor oral hygiene
o malocclusion
o extraction of neighboring tooth
o parafunctional habits
o occlusal overloading and poor oral health
o malocclusion with poor oral health
ECR is located most commonly in maxillary central incisors (29%), 14% in
maxillary canines, 14% in mandibular molars, and 14% maxillary premolars.
ECR is less frequently seen in mandibular canines (3%), mandibular centrals
(1%), and mandibular lateral (1%).
Radiographic features
• There is no usual radiographic appearance of ECR.
• The lesion may have well-defined or irregular margins in the cervical aspect of the
tooth.
• The radiographic appearance of ECR depends on the location, the extent of
invasion, and the relative proportions of fibro-osseous and fibrovascular tissue
occupying the resorptive cavity.
• All ECR defects presents as a radiolucency of varying radiodensity, often in but
not confined to the cervical region of the affected tooth or teeth.
Clinical features
• The clinical features of ECR are variable The process is very often quiescent
and asymptomatic, especially in the earlier stages, and absence of clinical
signs and symptoms is very common
• the diagnosis is commonly made as a result of a chance radiographic
finding.
• A pink or red discoloration may develop at the cervical region of the tooth.
• The discoloration is due to the fibrovascular granulation tissue occupying
the resorptive defect, it is also referred as “pink spot”
• The granulation tissue may perforate the enamel or dentin at the gingival
margin, giving the appearance of mild gingival hyperplasia.
• Loss of periodontal attachment may occur in the region of the resorption,
and probing of the resorptive defect or the associated periodontal pocket
causes the granulation tissue to bleed profusely.
CLASSIFICATION OF ECR:
Heithersay developed a four-stage classification system for ECR based on the
depth of penetration of the resorption in a buccolingual and apicocoronal
direction.
• Class 1: a small cervical lesion with shallow penetration into the dentine
• Class 2: a well-defined lesion close to the coronal pulp, but with little or no
extension into the radicular dentine
• Class 3: deeper invasion of the lesion into the coronal third of the root
• Class 4: a lesion extending beyond the coronal third of the root.
Management strategy:
Effective management of ECR depends on an accurate assessment of the true
nature and accessibility of the lesion.
The fundamental treatment objectives in ECR are
• To excavate the resorptive defect and halt the resorptive process
• To restore the hard tissue defect with an esthetic filling material
• Prevent and monitor the tooth for recurrence.
Management steps
1. Preparation and Access
o Raise a mucoperiosteal flap of appropriate dimensions to fully visualize the resorptive
defect.
o Ensure adequate surgical access to the site of resorption.
2. Excavation of Resorptive Tissue
o Use hand excavators to remove fibrovascular granulomatous tissue.
o Utilize ultrasonic instruments for removal of fibro-osseous tissue, especially when
contiguous with dentin.
o Employ a surgical operating microscope for accurate differentiation between sound dentin
and unwanted tissue.
o Consider intraoperative radiographs to ensure precise removal of unwanted hard tissue
while preserving sound dental tissue.
Continue………
3. Treatment with Trichloroacetic Acid
Apply a 90% aqueous solution of trichloroacetic acid to the excavated cavity.
Induce coagulation necrosis of resorptive tissue without harming periodontal tissue.
Allow the acid to penetrate and treat small, inaccessible channels of resorption.
4. Removal of Undermined Dentin or Enamel
Remove any undermined dentin or enamel at the periphery of the cavity using a bur in a high-
speed turbine.
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5. Restoration of the Cavity
Restore the excavated cavity with an esthetically acceptable restorative material, such as
composite resin, glass ionomer cement, or Biodentine.
Consider Biodentine due to its potential for acceptable esthetics and support for periodontal
ligament (PDL) attachment.
6. Closure and Securing the Flap
Replace and secure the mucoperiosteal flap in its original position to cover the restored cavity.
