2026 Catalog: All Courses

March 2026 Dental Pearl: Endodontics-Resorption
Root resorption is the pathological loss of dentin or cementum from the tooth root, initiated by clastic cells [osteoclasts/odontoclasts] due to trauma, infection or pressure. [NIH.gov]



There are 2 broad categories of resorption internal and external. The categories are based on where the resorption originated from.
In children, the roots of deciduous teeth naturally undergo resorption as part of the normal physiological process.
Root resorption in permanent teeth is almost always a pathological process.
2 things need to happen for root resorption to occur:
1] there must be a loss of the protective unmineralized surface layers of the tooth adjacent to dentin
2] there must be active on-going inflammation next to the exposed dentin.
Internal Root Resorption
-Usually asymptomatic, lesion is usually symmetrical oval size enlargement of the pulp space, and part of the pulp tissue must be vital for this process to be active, chronically inflamed pulp tissue, when the canal becomes necrotic the resorption stops.
-Treatment includes conventional root canal therapy often with intracanal medicament to eliminate the resorptive tissues, prognosis is very predictable and favorable. Coined“pink tooth of Mummery” by James Howard Mummery.
Types of External Root Resorption:
External Inflammatory Root Resorption
-Presence of sulcular bacteria, pressure from adjacent impacted teeth and pressure from orthodontic tooth movement were found to be associated with inflammatory root resorption. Once etiology was removed this would lead to the arrest of the active resorptive process.
-Preventative and interceptive strategies can be employed to treat/stop the inflammatory root resorption. Using calcium hydroxide is an intracanal medicament due to its antibacterial effect and it can influence the pH in dentin to aid in stopping the resorption.
External Replacement Root Resorption
Also known as “Ankylosis”. Trauma results in PDL destruction with exposure of cementum/dentin, teeth become “ankylosed”, pulp is the last thing involved. No radiolucency present. Bone undergoes continuous remodeling through one’s lifetime. Process cannot be stopped without disrupting the natural process of bone remodeling.
-Asymptomatic teeth can be maintained for many years. In children the treatment of choice is “decoronation”. Primary goal of decoronation is to remove all enamel from tooth since bone won’t grow onto enamel. The tooth structure will eventually be replaced with bone allowing normal growth of the osseous ridge in the area for potential implant placement. Replacement resorption can be a rapid or a slow progressive process.

External Invasive Cervical Resorption [ECIR]
Typically asymptomatic, pulp tissue found to be uninvolved in invasive cervical resorption. Resorptive process involved the cervical region of the tooth being invaded by fibro-vascular and/or fibro-osseous tissues from the PDL.
-Predisposing factors: Orthodontics, trauma, intracoronal bleaching, dentoalveolar surgery, periodontal therapy, bruxism, developmental defects, intracoronal restorations, viral infections, idiopathic. [Endodontics review study guide 2nd Ed.]


Heithersay classifications of ECIR or ECR: [Endodontics review study guide 2nd Ed.]
Class 1- small, well-defined lesion localized to cervical area and involving dentin
Class 2-slightly larger, well-defined lesion localized to cervical area but penetrating further into dentin and approximating the coronal pulp
Class 3-larger, less defined lesion extending into the coronal third of the root
Class 4-large lesion extending beyond the coronal third of the root.

Treatment: debride defect, treatment with trichloroacetic acid [TCA], restore with a bonded restorative material that promotes gingival attachment such as Geristore. Root canal therapy.
Mavridou proposed a 3 step strategy on how to manage external cervical resorption cases. 1] tooth extraction 2] monitoring of the tooth 3] treatment of the resorptive lesion.
In summary root resorption is a complex and often asymptomatic pathological loss of tooth structure that is driven by clastic cells. Various classification systems are used to categorize resorption. It is a multifaceted condition and a thorough understanding of the types of resorption, the causes of and the management strategies of resorption are all critical for an accurate assessment and treatment of these lesions.

Resources:
Blicher, B., Lucier Pryles, R., & Lin, J. [2022]. Endodontics review: A study guide [2nd ed.]. Quintessence Publishing.
Abbott PV, Lin S. Tooth resorption-Part 2: A clinical classification. Dent Traumatol. 2022 Aug;38[4]:267-285. doi: 10.1111/edt.12762. Epub 2022 May 23. PMID: 35605161; PMCID: PMC9543863.
Myers, G.L. [2025] Root Resorption-Endodontics. Colleagues for Excellence. American Association of Endodontists.
NIH.gov
AAE.org

1]   Know what root resorption is.
2]   Learn what two conditions are required for root resorption.
3]   Know what predisposing factors could cause ECIR

Emily Ikahihifo — Personal Description / Biography not available. For follow-up questions, please contact the speaker at emily.ikahihifo@ihs.gov.

The speaker has no conflicts of interest to report.

It is the policy of the Indian Health Service, Division of Oral Health, that faculty/planners disclose any financial or other relationships with commercial companies whose products may be discussed in the educational activity. The Indian Health Service, Division of Oral Health, also requires that faculty disclose any unlabeled or investigative use of pharmaceutical products and medical devices. Images that have been falsified or manipulated to misrepresent treatment outcomes are prohibited.

None of the faculty/planners for this activity has a conflict of interest, and there is no use of unlabeled or investigative pharmaceutical products or medical devices. No images have been falsified or manipulated to misrepresent treatment outcomes.The educational objectives, content, and selection of educational methods and instructors are conducted independent of any commercial entity.

The IHS Division of Oral Health is an accredited sponsor of continuing education under the American Dental Association Continuing Education Recognition Program (CERP). ADA CERP is a service of the American Dental Association to assist dental professionals in identifying quality providers of continuing dental education. ADA CERP does not approve or endorse individual courses or instructors, nor does it imply acceptance of credit hours by boards of dentistry. Concerns or complaints about a CE provider may be directed to the IHS at IHS CDE Coordinator or to the Commission for Continuing Education Provider Recognition at CCEPR.ada.org

Please Make Checks Payable to: Indian Health Service.

Tuition must be paid in full 8 weeks prior to the start date of any course. Request for refunds must be received in writing at least two weeks before the course begins. For each refund request, there will be an administrative charge of $100. No refunds will be made to registrants who fail to attend a course. If IHS CDE program cancels a course, then 100% of the tuition will be refunded.