The influence of occlusal scheme on biomechanical performances of short implant-supported fixed detachable prosthesis on maxilla arch: a finite element study

This research examines the impact of various occlusal schemes on the biomechanical behavior of posterior short implant- supported fixed- detachable prostheses using finite element analysis (FEA). A 3D model of a maxillary complete denture supported by implants was created. A model of a maxillary edentulous arch with dental implants ( 4. 1×8 mm and 4. 1×6 mm) and a zirconia prosthesis was constructed. In the anterior region, two 4.1×8 mm implants were used in both scenarios. In the posterior region, the short implant-supported prosthesis group (SI) received two 4.1×6 mm implants, while the All-on-4 group (AF) utilized two 4.1×8 mm implants tilted at a 30° angle. For the occlusal scheme, the bilateral balanced occlusion (BB) condition, a 50 N load was applied at the first molars and the first and second premolars on both sides. In the canine guidance (CG) condition, a 300 N load was applied to tooth number 13. Each load was distributed over five equally spaced points (0, 0.75, 1.5, 2.25, and 3 mm) from the central groove, then along an inclined plane. The study assessed strain, stress, and implant displacement under each condition. All measured values did not exceed the critical values: 150 MPa for stress (bone yield strength), 4000 microstrain (bone resorption threshold), or 5 µm (physiological implant mobility), indicating that there is no biomechanical failure occurred in all conditions. Among the simulations, CG produced higher biomechanical values than BB. This study’s findings suggest that both BB and CG are biomechanically viable for use in implant- supported fixeddetachable prostheses, though BB is more favorable due to its lower impact on both bone and prosthetic components.