Evaluation of Zirconia and Cobalt-Chrome for Custom-Milled Framework Design for an Implant-Supported Full-Arch Fixed Dental Prosthesis: A Finite Element Analysis

The demands for aesthetics in implant-supported full-arch prosthesis increased the use of zirconia as framework material due to its aesthetics, biocompatibility and high survival rate. The aim of this study was to compare the mechanical response of Zirconia and CoCr custom-milled framework indicated for maxillary prosthetic rehabilitations using the Finite Element Method. To perform this simulation, a custom-milled framework design for an implant-supported full-arch fixed dental prosthesis was used. The geometries of bone, prosthesis, implants, abutments and prosthetic screw were modelled. The mechanical properties for each isotropic and homogeneous material were simulated. Two frameworks were simulated (YZTP and CoCr Alloy). A load of 500 N load was applied on the occlusal surface of the right upper first molar. The results were analysed in terms of displacement, von Mises stress and microstrain. After the simulation processing, it was not possible to observe difference for prosthesis displacement or stress concentration regarding the framework material. The use of YTZP exhibited the lowest stress magnitude for implant (60 MPa) near the load application site, in comparison with the metallic framework (76 MPa in the same region). The same behaviour was calculated for the microstrain results in peri-implant region. The use of YZTP to perform a custom-milled framework design for an implant-supported full-arch fixed dental prosthesis may have acceptable mechanical response for the analysed structures.