Influence of thread shape and inclination on the biomechanical behaviour of plateau implant systems

To assess the influence of implant thread shape and inclination on the mechanical behaviour of bone-implant systems. The study assesses which factors influence the initial and full osseointegration stages. By the permutation of three thread shapes and three thread inclinations, nine geometric configurations were obtained. Two different osseointegration stages were analysed. In total, 18 different FE models were analysed and two load conditions were applied to each model. The mechanical behaviour of the models was analysed by Finite Element Analysis. Static linear analyses were also carried out. ANOVA was used to assess the influence of each factor. Models with a rectangular thread and 6◦inclination provided the best results and reduced displacement in the initial osseointegration stages up to 4.58%. This configuration also reduced equivalent VM stress peaks up to 54%. The same effect was confirmed for the full osseointegration stage, where6◦inclination reduced stress peaks by up to 62%. The FE analysis confirmed the beneficial effect of thread inclination, reducing the displacement in immediate post-operative conditions and equivalent VM stress peaks. Thread shape does not significantly influence the mechanical behaviour of bone-implant systems but contributes to reducing stress peaks in the trabecular bone in both the initial and full osseointegration stages.