咬合力下における歯牙および歯槽壁の応力分布に関する光弾性的研究

抄録

In this paper, the photoelastic method was used to determine preferable forms of models of a tooth and an alveolus from the biomechanical viewpoints. The wedge-formed tooth model was used in this experiment and the models of a tooth and an alveolus were prepared from epoxy resin. A periodontal membrane-model was sandwhiched between the tooth- and alveolar-models. The concentrated load corresponding with occlusal force was applied to the model. The stress concentrations and distributions under the load were investigated by varing each radius of curvature of the tooth root apex and that of the alveolar fundus. When the radius of curvature of the tooth root apex is larger than that of the alveolar fundus, the following results are obtained. Namely, a zero point, which indicates the zero stress, and low stress zones occur always in the tooth root apex and on the alveolar socket near the alveolar fundus regardless of positions of loading. The tooth root apex corresponds to the place where an apical foramen locates. It seems that the alveolar socket near the alveolar fundus corresponds to the place where nerves and blood vessels pass through principally. These places are important anatomically for the reason that nerves and blood vessels converge there. From the functional viewpoints, it is reasonable that nerves and blood vessels locate in the place of safety where stress concentrations do not occur. Therefore, it seems that the form of the model in which the above result occurs is more preferable.