Periapical healing and continued root maturation following endodontic surgery and apexification.

Persistent periapical lesions associated with iatrogenic errors, such as overextended silver cone obturations, present a significant clinical challenge that often necessitates multidisciplinary treatment. This case report describes the successful management of a 25-year-old female presenting with a large (1.5 cm × 1.2 cm), unilocular periapical cyst-like lesion involving the maxillary anterior teeth (11, 12, and 21). The treatment followed a staged protocol: initial nonsurgical retrieval of overextended silver cones was performed, followed by mineral trioxide aggregate (MTA) apexification for the teeth with open apices (11, 21). Subsequent endodontic surgery was performed, incorporating a 3-mm root-end resection for tooth 12, ultrasonic retrograde cavity preparation, and MTA root-end filling. After the 10-month follow-up, the patient remained asymptomatic, with radiographs demonstrating significant bone regeneration and evidence of "continued root maturation" or lengthening.