Three-dimensional finite element analysis of the biomechanical behavior of implant retained prostheses with different materials in the posterior maxilla

Abstract

<strong>Background:</strong> <br/> The biomechanical performance of implant-supported prostheses is strongly influenced by prosthetic design and material properties. In the posterior maxilla, reduced bone density and anatomical limitations often necessitate the use of cantilevered restorations, which may alter stress distribution and affect long-term clinical outcomes. This study aimed to evaluate the influence of prosthetic configuration and material selection on stress distribution in implant-supported prostheses. <br/> <strong>Methods:</strong> <br/> A patient-specific three-dimensional maxillary model was reconstructed from cone-beam computed tomography (CBCT) data. Three prosthetic designs were analyzed: fixed–fixed (MF), mesial cantilever (MM), and distal cantilever (MD). Each configuration was restored using monolithic zirconia (Zr) and polyetherketoneketone (PEKK). Finite element models were created and subjected to a static axial load of 300 N simulating functional occlusion. von Mises stress values were calculated for the prosthesis, implants, and surrounding bone. <br/> <strong>Results:</strong> <br/> Prosthetic design significantly influenced stress distribution. The fixed–fixed configuration demonstrated the lowest stress values in implants and bone, indicating the most favorable biomechanical behavior. Cantilever designs, particularly distal cantilevers, produced markedly higher stress concentrations. The highest stress values were observed in the distal cantilever PEKK model, especially in the implant and peri-implant bone. Regarding materials, zirconia showed higher stress within the prosthesis but reduced stress transfer to implants and bone, while PEKK reduced prosthetic stress but increased stress transmission to supporting structures. <br/> <strong>Conclusion:</strong> <br/> Both prosthetic design and material significantly affect the biomechanical behavior of implant-supported prostheses. Fixed–fixed zirconia restorations provided the most favorable stress distribution, whereas cantilever configurations (especially distal cantilevers) should be carefully considered due to increased biomechanical risk. Within the limitations of finite element analysis, these findings emphasize the importance of appropriate prosthetic designing and material selection. Further experimental and clinical studies are recommended to validate these results.