Canal configuration of the mesiobuccal root of the maxillary first molar: conventional and surgical approaches

One of the primary causes of endodontic failure is the presence of untreated canals. Although the maxillary first molar has been described as the most endodontically treated tooth, the canal configuration has been the least understood. The purpose of this article is to present, with the aid of several clinical cases, a review of the literature regarding the frequency, the location, and the incidence of the second mesiobuccal canal in relation to the maxillary first molar, both for conventional and surgical approach.