Role of mineral trioxide aggregate in management of external root resorption.

External root resorption (ERR) is a lytic process occurring in the cementum or cementum and dentin of the roots of teeth. Here we report a case of inflammatory ERR in a mandibular right molar in a 22-year-old male patient with history of incomplete root canal treatment with the same. Considering the biological properties of mineral trioxide aggregate cement, especially its alkalinity and sustained calcium hydroxide release, this material was used for the treatment of ERR, followed by permanent prosthesis. The clinical and radiographic follow-up for 24 months revealed that treated teeth were functional, the progression of the ERR had ceased, the resorptive area were replaced with newly formed bone and periapical radiolucencies was healed.