06/05/2026
Internal Resorption ⬇️
▶️ Definition
➟ A progressive, destructive process of intraradicular dentin that begins from within the root canal wall.
➟ It is caused by multinucleated dentinoclasts or odontoclasts acting on the internal dentin surface.
▶️ Etiology Causes
➟ Most common cause is dental trauma.
➟ Other causes include deep caries, excessive heat during restorative procedures, and orthodontic tooth movement.
➟ Crucial board fact: Internal resorption requires a vital, vascular pulp below the lesion to supply clastic cells with blood and nutrients.
➟ If the pulp becomes completely necrotic, internal resorption stops.
▶️ Key Clinical Symptoms High-Yield
➟ Usually asymptomatic and often discovered incidentally on routine radiographs.
➟ Pink tooth of Mummery may be seen if the lesion is in the coronal pulp chamber.
➟ The pink color occurs because highly vascular inflamed granulation tissue shines through thinned enamel and dentin.
▶️ Radiographic Findings High-Yield
➟ Smooth, well-defined, symmetrical ballooning or oval radiolucent enlargement of the root canal space.
➟ The original root canal outline is lost or distorted at the site of the lesion.
➟ The lesion usually stays centered in the canal on angled radiographs because it is located inside the canal.
▶️ Complications
➟ If untreated, the resorptive defect may progress through dentin and cementum.
➟ This can cause intraosseous root perforation.
➟ Perforation makes the tooth much harder to save and lowers the prognosis.
▶️ Treatment & Prognosis
➟ Definitive treatment is prompt root canal therapy.
➟ Removing the vital pulp cuts off blood supply to odontoclasts and stops the resorptive process.
➟ Warm vertical condensation or thermoplasticized gutta-percha may be needed to fill the ballooned, irregular defect.
➟ Prognosis is excellent if treated before perforation.
➟ Prognosis becomes poor or questionable if a large perforation has already occurred.
❇️ Board Exam Differentiator
➟ Internal resorption: Canal outline bulges and is lost within the defect.
➟ External resorption: Canal outline can still be traced through the radiolucent lesion.
