Concrescence of permanent maxillary second and third molars: case report of non-surgical root canal treatment.

Concrescence is a rare developmental anomaly with an overall incidence of 0.8% in the permanent dentition. While many case reports describe the treatment of concrescence with extraction, there are few reports of non-surgical root canal treatment (NSRCT), due to the atypical root form, canal morphology, and technical difficulties involved in concrescence. This unique case report describes a technical modification of NSRCT that can retain joined posterior maxillary teeth to maintain natural posterior occlusion without surgical intervention or dental implants, thereby avoiding the risk of damage to a large portion of the alveolar bone near the maxillary sinus.