Innovative Design of a New Intraosseous-Subperiosteal Combined Implant for Severe Atrophic Edentulous Dentition: A Finite Element Analysis

Background: To develop a new combined intraosseous-subperiosteal implant for severely atrophic edentulous mandibles and analyze its biomechanical properties via finite element analysis. Methods: We reconstructed the bone model using CBCT data from a patient with an edentulous mandible. Subsequently, we designed intraosseous implants based on the bone volume within the 3-matic software, and the superstructure abutments were designed on top of it. Then, a subperiosteal titanium mesh base was designed on the surface of the mandible. Finally, the intraosseous implants, the abutments, and the subperiosteal titanium mesh base were integrated to obtain a new intraosseous-subperiosteal combined implant. Four groups of finite element models were assembled, varying in implant design and abutment count. Four loading modes were identified: anterior vertical, unilateral molar vertical, bilateral molar vertical, and unilateral molar lateral occlusions. Finite element analysis was used to analyze the maximum and minimum principal stresses in the peri-implant bone and the von Mises stresses in the implants, abutments, screws, and titanium nails. Results: A new intraosseous-subperiosteal combined implant for an extremely atrophic edentulous mandible with severe jaw was successfully constructed, which consisted of three main components: a subperiosteal titanium mesh base combining mesh and ribbon morphology, the endosteal implant, and the abutment. The results of finite element analysis demonstrated that the maximum and minimum principal stresses among all groups remained below the yield strength of 140 MPa, while the von Mises stresses in the implant component groups were within the material’s tolerable limits. The surrounding bone stress can be reduced with the novel-designed implant. Increasing the number of abutments can decrease the stress on the implant components. Conclusions: The new implant developed in this study demonstrated enhanced biomechanical properties in simulated applications for dental implant prosthetics in severely atrophic edentulous mandibles. This innovative design offers a promising alternative for overcoming the challenges associated with dental implant prosthetics in patients with severely atrophic mandibles, potentially improving outcomes in this patient population.