Methods: A three-dimensional finite element FPD model of the maxillary second premolar to the second molar was designed. Three load conditions were applied statically on functional cusps in horizontal (57.0 N), vertical (200.0 N) and oblique (400.0 N, è=120°) directions. Four standard framework materials were evaluated: polymethyl methacrylate, base-metal, porcelain fused to metal and porcelain. All materials were considered to be linear elastic, homogeneous and time independent.
Results: The maximum of von Mises stress in oblique direction was higher than vertical and horizontal directions in all case studies. In crestal bone section, the maximum von Mises stress was observed in polymethyl methacrylate through oblique direction of the load with the value of 53.78 MPa. The numerical results demonstrated that maximum stress was generated at the connector region of the FPD in all case studies.
Conclusions: A noticeable difference between bone stress distribution using different prosthesis materials were not observed. Although higher stress value could be seen in polymethyl methacrylate, all types of prosthesis yielded the same stress distribution pattern in FPD. More clinical studies are needed to evaluate the success and failure of these materials.