[A photoelastic study of the stress distribution in the surrounding tissues of the abutments of a fixed partial denture with tilted molar abutments].

The purpose of this study was to evaluate the stress distributions to the abutments of a fixed partial denture with tilted molar abutments. In cases of the lower 1st molar being missing four 2-dimensional photoelastic models with 3- unit fixed partial dentures of which the 2nd molars were tilted 0 degrees, 10 degrees, 20 degrees and 30 degrees toward the 2nd premolar were made. A vertical load of 50 lbs was applied to the 1st and 2nd molar in each case. Two-dimensional photoelastic stress analysis was used, and the stress areas were recorded photographically. The results were as follows; 1. When the vertical load was applied to pontic and 2nd molar on the central fossae, the magnitude of stress distribution of the surrounding tissues of the root of the 2nd premolar was increased incrementally with increasing inclination. 2. Under two loading conditions, the stress distributions were directed to the long axis of the abutments. 3. In this experiment, no stress distributions were observed on the mesial area of the mesial root of the second molar.