Endodontic retreatment of a maxillary second molar with three separate buccal roots.

A rare case of a four-rooted maxillary second molar in a 39-year-old male patient is reported. After clinical and radiographic examination, two separate mesio-buccal roots were detected, and a treatment plan consisting treatment of the mesio-buccal roots and retreatment of the disto-buccal and palatal roots was made to resolve the previous treatment failure. The tooth was treated by orthograde endodontic retreatment in two visits. Mesio-buccal canals that were located in the separate mesio-buccal roots (which were missed in previous treatment) were found and treated. The case report underlines the importance of complete knowledge about root canal morphology and possible variations, coupled with full clinical and radiographic examination, in order to increase the ability of clinicians to treat difficult cases.