Introduction: One of the main causes of failure in endodontic treatment of maxillary molars is the inability to locate the secondary mesiobuccal canal, preventing proper debridement or obturation. The aim of this study was to describe in vivo the prevalence and location of the MB2 in the mesiobuccal root of the maxillary first molar through cone-beam computed tomography.
Materials and Methods: 60 maxillary first molars were analysed. To detect the MB2 canal, the observation and measurements were done 1 mm apically to the pulpal floor to standardize the methodology. The central point of the MB1, MB2 and P canals were located geometrically. Then straight lines were projected, connecting different points: line MB1-P and line MB1-MB2. A third line, MB2-T, corresponding to a perpendicular line between MB2 and MB1-P (T point) was drawn. The T point corresponding to a perpendicular line between the MB2 and MB1-P. The distance between the lines was measured in millimeters. The results were analysed using descriptive statistics, with a statistically significant value of p<0.05.
Results: The MB2 canal was identified in 68.3% of cases. The average distance between MB1 and P was 6.91 ± 1.47 mm, between MB1 and MB2 2.61 ± 0.64 mm and MB2-T 1.26 ± 0.36 mm. There were no statistically significant differences in the presence and/or absence of the MB2 canal in terms of age or gender.
Conclusions: The MB2 canal was found in a high percentage in the maxillary first molar. When present, it is advisable to take the main mesiobuccal canal as a parameter and explore some millimeters mesially and palatally to display it. CBCT is a good diagnostic tool for its detection and exploration.