抄録
It is recognized that the occlusal force is transmitted through the tooth and the periodontal membrane to the alveolar bone. As the periodontal supporting tissue is destroyed by periodontal disease, the occlusal force may tend to concentrate to the remaining tissue. In this study, the mechanical stress to the root apex was experimented by the various conditions of the alveolar bone defects. The quasi-three dimensional photoelastic models of premolar and molar mandibular teeth were used to estimate the stress. These models were loaded up to 98.0N, the color fringe changes were observed. This study suggests that the mechanical stress from the occlusal surface was spread to the wide area of alveolar bone and its surrounding tissue as the load was increased. The stress was concentrated to the root apex regardless of the shape of infrabony defects, and compression and tension of tooth were observed on the root surface. The color fringe pattern was changed by infrabony wall defect.
