Numerical Evaluation of Micromotions and Wear of Two Different Dental Implants in Case of Isotropic and Anisotropic Human Jaw

Nowadays, dental prostheses are certainly a valid and safe solution for oral cavity issues in terms of reliability and long-term survival. Unfortunately, mechanical efforts, the presence of bacteria, and the corrosive environment may even jeopardize the functionality and the stability of medical devices. In this light, one of the potential failure causes is certainly mechanical wear that originates from the micromovements between the abutment and the implant, with the release of toxic ions in the bone and near tissues. The purpose of this work is therefore to evaluate, by numerical analysis, the sliding and consequential material loss according to Archard’s law for four loads and in the case of two implants having different designs and fixing mechanisms. The jawbone, characterized by isotropic or anisotropic behavior, was composed of cortical and cancellous parts and was considered completely osseointegrated with the implants, while a frictional contact with the abutment was involved. The effect of fixture designs, applied forces and the kind of jawbone was discussed and interpreted, analyzing similarities and differences. Micromovements, mostly diffused in the buccolingual direction, were strongly affected by the conical angle, whereas wear was found to also be correlated also with the kind of implant and bone properties.