External root resorption (ERR)

Presentation about external root resorption, subdivisions and treatment

1. External Root Resorption (ERR) Dr. Khawla Khalid Abdalla

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 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 12 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. 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.

9. 3. External Replacement (Ankylotic) Resorption This is the process of replacement of root surface with bone otherwise known as ankylosis.

10. 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 allow for growth to cease before considering dental implant replacement

11. 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

12. Pathogenesis: • Initial cervical resorption cavity gradually spreads • Progress in apical & coronal direction – leading to root fracture

13. 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.

14. 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.