This document discusses the different types of root resorption, including external root resorption. External root resorption is classified into external surface resorption, external inflammatory resorption, external replacement resorption, and external cervical resorption. External surface resorption is a self-limiting resorption caused by trauma or orthodontic treatment. External inflammatory resorption is often seen radiographically as an extensive lesion caused by necrotic pulp. External replacement resorption replaces the root surface with bone in a process called ankylosis. External cervical resorption is a localized resorptive lesion of the cervical area that may progress in an apical or coronal direction.

1. EXTERNAL ROOT
RESORPTION
(ERR)
D R . K H AW L A K H A L I D A B D A L L A

2. OUTLINE
 Types of root resorption
 External resorption
 External surface resorption & treatment
 External Inflammatory Resorption & treatment
 External Replacement Resorption & treatment
 External Cervical Resorption & treatment

3. TYPES OF ROOT RESORPTION
i. Internal Root Resorption
• Root Canal Replacement Resorption
• Internal Inflammatory Resorption
ii. External Root Resorption
• External Surface Resorption
• External Inflammatory Resorption
• External Replacement Resorption
• External Cervical Resorption
iii. Transient inflammatory resorption

4. EXTERNAL ROOT RESORPTION
• Definition
External resorption is the progressive loss of tooth structure (Dentin and
cementum) from the external surface of the tooth by the action of
osteoclasts.
• Classification:
• External Surface Resorption
• External Inflammatory Resorption
• External Replacement Resorption
• External Cervical Resorption

5. 1. EXTERNAL SURFACE RESORPTION
• Is a self-limiting resorption that is transient.
• Small, superficial resorption cavities in the cementum and the outermost
layers of the dentin without an inflammatory reaction in the PDL.
• Caused by: traumatic injuries or orthodontic treatment..
• When trauma/pressure discontinued – spontaneous healing occur – -
typical feature of REPAIR RELATED RESORPTION
• This process is thought to be exceedingly common but grossly under-
reported as it is sub-clinical.

6. TREATMENT
• Endodontic Implication:
• Primarily periodontal injury – endodontic intervention not indicated.
• If trauma/pressure eliminated – almost 100% repair
• If root apex resorbed - excessive mobility becomes a problem, if root is shorter than
mm

7. 2. EXTERNAL INFLAMMATORY
RESORPTION
• Is often seen radiographically as an extensive peri-radicular
radiolucency associated with an extensive inflammatory response to
endodontic pathosis.
• Causes: Necrotic pulp.
• Bacteria primarily located in pulp & dentinal tubules trigger
osteoclastic activity resulting in both tooth and bone resorption..
• Resorption can affect all parts of root.
• Diagnosed 2-4 weeks after injury.
• Resorption rapidly progress – total root resorption within few months.
• Most common after avulsion and luxation injuries

8. Clinical Findings:
• Increased mobility
• Dull percussion tone (Tender to percussion and palpation)
• Sometimes tooth extruded
• Negative EPT and thermal testing
• Sometimes sinus tract develop
Radiographic Findings:
• Radiolucency on the external root surface and adjacent bone.
• Extensive root resorption if lesion is long standing in origin

9. TREATMENT
• Endodontic Implication:
• Non-surgical root canal treatment is indicated - to remove
osteoclast promoting factors (bacterial toxins)
Treatment:
• Use of Calcium Hydroxide intracanal medicament is recommended
to remove bacterial stimulation from both the root canal and
dentinal tubules.

10. 3. EXTERNAL REPLACEMENT (ANKYLOTIC)
RESORPTION
• This is the process of replacement of root surface with bone otherwise known as
ankylosis.
Causes
Severe traumatic injuries (intrusive luxation or avulsion)
Clinical Findings Appear firm in socket
High pitched metallic sound on percussion
Infra-occlusion may be present
Radiographic Findings
Resorption lacunae are filled with bone
Periodontal ligament space is missing

11. TREATMENT
• Endodontic implications:
• Endodontic therapy- cannot arrest progressive ankylosis related resorption
• In vital pulp - no endodontic procedure
• In pulp necrosis - root canal treatment
• Prevention by minimizing periodontal ligament damage immediately following an
injury is the only treatment.
• Decoronation and submergence maybe an option in the developing dentition to
for growth to cease before considering dental implant replacement

12. 4. EXTERNAL CERVICAL RESORPTION
• External cervical resorption is a localized
resorptive lesion of the cervical area of the root
below the epithelial attachment (thus it may not
always be in the cervical region.)
• In a vital tooth unless the lesion is extensive there
is rarely pulpal involvement.
• Potential predisposing factors: dental trauma,
orthodontic treatment, intracoronal bleaching,
periodontal therapy and idiopathic origin.
• Heithersay et al – studied 259 teeth with invasive
cervical resorption –
23% : related to orthodontic treatment
15% : acute trauma
14% : cervical restoration

13. • Pathogenesis: • Initial cervical resorption cavity gradually spreads • Progress in apical &
coronal direction – leading to root fracture
Expanding lesion- show as
a “pink spot” next to
cervical margin
Clinical
Findings Cervical bowl-shaped
lesion is the start of
invasive progression of
resorption in coronal &
apical direction.
Pulp canal not invaded in
initial phase
Radiographic
Findings

15. TREATMENT
• Endodontic Implications:
• Pathology entirely related to PDL defect
• Does not need endodontic treatment primarily
• When invasive nature finally encroaches pulp - need endodontic treatment
• Treatment:
• • Essentially, treatment involves complete removal of the resorptive tissue and
restoring the resulting defect with a plastic tooth-coloured restoration.

16. REFERENCES
• https://pocketdentistry.com/root-resorption-2/
• Darcey, James & Qualtrough, Alison. (2013). Resorption: Part 1. Pathology,
classification and aetiology. British dental journal. 214. 439-51. 10.1038/sj.bdj.2013.431.
• Z. F., I. T., & S. L. (2003). Root resorption - Diagnosis, classification and treatment
choices based on stimulation factors. Dental Traumatology, 19, 175-182.