How is internal resorption identified radiographically and what is the general treatment approach?

• A. Symmetrical, well-defined circular radiolucency within canal space; address by cleaning/debriding the resorptive defect and obturating to seal
• B. Irregular radiolucency external to the root
• C. Diffuse root resorption with no canal involvement
• D. No radiographic signs of resorption

Answer: (A)

Internal resorption shows up on radiographs as a symmetrical, well-defined radiolucent area within the root canal space, usually circular or oval and centered on the canal. The resorptive process enlarges the canal from the inside while the outer root outline remains intact (unless perforation has occurred). This pattern often accompanies a vital pulp and inflammatory activity that stimulates odontoclasts to resorb dentin from within. The usual treatment is endodontic therapy to remove the resorbing tissue and seal the canal, stopping the process. Practically, this means accessing the canal, cleaning and debriding the resorptive tissue, shaping to remove any resorbing tissue, and obturating with gutta-percha and sealer to seal the defect and prevent reinfection. Calcium hydroxide may be used as an intracanal medicament to help arrest resorption before final obturation. If perforation into the root surface has occurred or the resorption is extensive, additional procedures may be needed beyond standard nonsurgical endodontic treatment.

External resorption would present as an irregular radiolucency outside the canal space; no radiographic signs would suggest resorption.