Enhanced implant longevity: Finite element optimization of all-on-four implant designs to minimize jawbone stresses

The all-on-four treatment concept is widely used to rehabilitate edentulous dental arches; however, its biomechanical effect on supporting jawbones requires careful evaluation. This study aims to optimize the all-on-four implant design to minimize cortical bone stress using finite-element analysis (FEA). A three-dimensional FEA model was developed based on the mean average dimensions of Japanese edentulous mandibles (Takahashi et al. 2010). Implants (length = 12-16 mm and diameter = 3-5 mm) were placed between the two mental foramina with two parallel anterior implants positioned at distances ranging from 9.6-15 degree from the mandibular midline. Posterior implants are angled from 1-45° with lengths varying between 12-18 mm. A rigid superstructure splints all implants and an occlusal load of 50 N was applied at distal ends. The maximum Von Mises stress on the cortical bone was measured. The adaptive optimization approach identified eight optimal design configurations. These designs results in a peak Von Mises stress of 2.26 MPa which demonstrate 32% reduction compared with previous findings by Takahashi et al. (2010). The optimized all-on-four configuration significantly reduces cortical bone stress while accommodating anatomical variability. This approach offers clinical insights into improving implant longevity and outcomes in edentulous patients.