Cone-beam computed tomographic analysis of dentinal wall thickness in the danger zone of the first and second mesiobuccal canals of maxillary first molars

Aim: This study evaluated the dentin thickness at the furcation level and danger zone of the first and second mesiobuccal (MB1 and MB2) canals of maxillary first molars and determined the dentin thickness between genders and different age groups. Materials and Methods: One hundred cone-beam computed tomography images of maxillary first molars with MB2 canals were evaluated from radiology centers in Bangalore. Images were prepared using CS three-dimensional Imaging Software Version 3.8 (Carestream Dental India, Mumbai, India), with a field of view of 8 cm × 8 cm and resolution of 0.1 mm. Axial cross-sections of 0.1 mm thickness were examined at a distance of 1 mm at four different levels, at the level of the furcation, followed by 2 mm, 4 mm, and 6 mm below the furcation (×10, magnification). The distances from the center of the MB1 and MB2 canals to the nearest point on the distal surface of the mesiobuccal root were measured. Statistical Analysis: Student paired t-tests were used for statistical analysis. Results: The dentin thickness in the MB2 canal was significantly less than that in the MB1 canal in all samples at all levels ( P < 0.001). The least mean dentinal wall thicknesses of the MB1 and MB2 canals were 4 mm below the furcation. Conclusions: Danger zone lies 4 mm from the furcation level for both MB1 and MB2 canals. Dentinal wall thickness at 4 mm below the furcation showed statistically significant differences with respect to both MB1 and MB2 canals in females and patients aged <40 years.