Abstract

Aim: To assess the peri-implant stresses produced by cobalt chromium and zirconium frameworks for mandibular prosthesis using finite element analysis.

Material and methods: This investigation was performed using three-dimensional finite element models of an edentulous mandible restored with a prosthesis supported by four implants. While the posterior implants were positioned at the second premolar location with a 17-degree distal angulation, the anterior implants were positioned vertically and bilaterally in the lateral-canine area. All of the implants had multi-unit abutments. For the first model, a zirconia framework was constructed, while a cobalt-chromium framework was envisaged for the second. Assessments were made of the directional deformation, maximum principal stresses, and Von Misses stresses.

Results: Von Mises stress, maximum principal stress, and directional deformation were assessed in the peri-implant bone area. Von Mises stresses, maximum principal stress and directional deformation on the screw-retained prosthesis were very similar in cobalt chromium and zirconium frameworks compared to the underlying bone and implants.

Conclusion: Zirconium frameworks are comparable to cobalt-chromium frameworks as regards the stresses induced at the per-implant bone, they showed comparable deformation values at the fixation screws.