A photoelastic analysis of the stress distribution in bone supporting fixed partial dentures of rigid and nonrigid design.

Within the limitations of the experiment, the following conclusions can be made from this investigation: 1. Under conditions of vertical loading, the rigid fixed partial denture design does not permit independent response by either abutment. The nonrigid fixed partial denture design allows the abutments some independence in response to vertical loading 2. The stress distributions and concentrations produced in the supporting bone are favorably altered by the placement of a fixed partial denture of rigid or nonrigid design. 3. The distribution of stresses in the supporting bone varies with the number and location of the loading sites. 4. Under conditions of vertical loading, the Ney and Stern nonrigid fixed partial denture designs exhibit no significant differences in stress distribution or concentration.