[Mechanical studies on the dental bridges by the finite element method. (1)--An abutment tooth model-- (author's transl)].

Biomechanical considerations are very important to design a prosthetic appliance; however, there have been no satisfactory quantitative studies of such problems, mainly because theoretical and experimental models are unable to represent exactly the natural conditions in the mouth. The finite element method has been successfully applied in each field of applied mechanics and found to be effective for the structural analysis of the biological systems, for it has the advantage of greater versatility for modelling. Accordingly, this analytical, computer-aided method was applied to the dental bridges to evaluate the loads transmitted to the abutment tooth and the stress distributions in the supporting tissues. As the preliminary study a two-dimensional model was constructed to simulate the tooth subject to a vertical and a horizontal load and a moment at the coronal portion. The stress distributions in the tooth and the periodontal membrane and the force distributions on the socket wall were calculated for three load conditions. The tooth mobility and the center-of-rotation position were compared with actual data available in some literatures and the characteristics of tooth support were discussed in terms of three spring constants.