2018 年 9 巻 2 号 p. 78-85
Unfortunately, it is not uncommon to encounter cases of tooth fracture in everyday clinical practice. In clinical tooth fracture, the direction of the fracture depends on the site, and in tooth root fractures, the buccolingual direction is common in premolars and the mesiodistal direction is common in molars. Here, in order to investigate the probability of fracture depending upon the anatomical structure of the tooth root, we constructed models of one-third of the root on the crown side of premolars with two roots based on cone-beam computed tomography (CBCT) coronal sections, and we carried out a structural analysis using frames. The results suggest that if a dividing wall is removed in order to treat two root canals as a single canal, stress concentrates in a buccolingual direction and there is a high probability of fracture occurring from the inside toward the outside.
