Effects of mesiodistal inclination of implants on stress distribution in implant-supported fixed prostheses.

PURPOSE Patterns of von Mises stress values surrounding implants supporting fixed prostheses in the posterior edentulous maxilla were evaluated using 3-dimensional finite element analysis. MATERIALS AND METHODS Implants were placed in maxillary bone in 2 different configurations. In the first configuration, implants were placed in the first premolar, second premolar, and second molar regions; in the second configuration, implants were placed in the second premolar and second molar regions, and a mesial cantilever was extended to the space of the first premolar tooth on the superstructure. On the implant placed in the socket of the second molar, 3 different inclinations were used (0, 15, and 30 degrees). Loading was applied in the vertical, oblique, and horizontal axes. RESULTS Inclination of the implant in the molar region was found to result in increased stress. Significant increase in stress on the implant embedded in the premolar region was also seen in the design with the cantilever as compared to the conventional prosthesis design. DISCUSSION The stress concentrations observed at the neck of the implant were similar to results reported in the literature. CONCLUSION The highest stress value obtained in the study was 194.2 MPa with oblique loading. This value did not exceed the endurance limit of pure titanium, which is 259.9 MPa.