Biomechanical Performance of Implant-Tooth-Supported Prostheses: A Numerical 3D Finite Element Analysis

To assess the biomechanical behaviour of implant-tooth-supported (hybrid) prostheses, compared with an implant-implant-supported prosthesis, utilising two different prosthetic materials, employing finite element analysis (FEA).

Three digital models, derived from a CBCT-scanned edentulous mandible, were designed: two hybrid configurations (M1: distal implant-first premolar; M2: mesial implant-first molar) and an implant-implant-supported prosthesis (M3). A biomechanical modelling workflow was carried out (Mimics for segmentation, 3-Matic for bone/mucosal layer refinement, Exocad DentalCAD and SolidWorks for implants, abutment and prosthesis integration, and ANSYS for meshing and FEA). Assuming isotropic/elastic material properties, zirconia and polyetherketoneketone (PEKK) were selected as prosthetic materials. Models were subjected to a static vertical load (100 N). von Mises stress and total deformation were analysed to evaluate structural responses.

M3 demonstrated the most favourable biomechanical profile, exhibiting the lowest von Mises stress magnitudes alongside the highest overall deformation. In hybrid models (M1, M2), stress maxima were localised at the pontic-tooth connector regions and, in M1-PEKK, reached 261 MPa in the screw. Cortical bone and prepared teeth exhibited higher stress in distally anchored hybrid systems (M1) compared to mesially supported designs (M2), regardless of the prosthetic material. Comparative analysis revealed that zirconia-based prostheses generated higher stress concentrations in bone (≤35 MPa) compared to PEKK, whereas the PEKK prosthesis itself exhibited greater structural deformation (70 µm in M1-PEKK).

Hybrid implant-tooth-supported prostheses can act as a reliable alternative to implant-implant ones and eliminate cantilever extensions; however, their use should be reserved for carefully selected cases to avoid biomechanical incompatibilities.