Inadequate treatment: a pathway to surgery.

A patient developed postendodontic pain 3 years after undergoing root canal therapy in a maxillary first premolar tooth. Radiographic examination revealed that a recently extracted impacted second premolar had originally obscured the x-ray view of a third root on the first premolar. Endodontic therapy in the unfilled root was rejected because the tooth had been restored with full coverage. Apicoectomies and retroseals were performed on all roots, and the tooth became asymptomatic.