A photoelastic study of rests on solitary abutments for distal-extension removable partial dentures

With a distal-extension removable partial denture, maximum use of existing oral structures can aid in the total support of the prosthesis and reduce the force on the solitary abutment. Four rests with relieved and unrelieved guide plates were evaluated for optimum stress distribution around the root of a solitary premolar abutment. These rests were the mesial, the distal, the mesial and distal, and the continuous rest. The findings demonstrated that The continuous rest had the most favorable stress concentration. All other rest designs demonstrated more lateral stress than the continuous rest. Relieved guide plates demonstrated 58% less maximum shear stress in the apical portion than unrelieved guide plates.