Mandibular second molar with C-shaped canal morphology and five canals: report of a case.

This article reviews a case involving endodontic treatment of a mandibular second molar with C-shaped canal morphology and five separate canals. The C-shaped canal variation of morphology is unusual and can lead to difficulties during treatment. Preoperative radiographs are limited in their ability to detect this entity; for a favorable treatment outcome, knowledge of the C-shaped canal's existence and morphology is essential.