The Influence of Various Superstructure Materials on Stress Distribution for Implant-Supported Prosthesis: Three-Dimensional Finite Element Analysis

In different applied load scenarios, this study evaluates the distribution of stress in the implant and bone exerted by zirconia, lithium disilicate, and cobalt chromium alloy. A 3D virtual model of a mandibular three-unit implant-supported prosthesis was created using SolidWorks 2022. The model featured two 12-mm Straumann Ti-Zr (Roxolid) implants with diameters of 4.5 mm and 4 mm. Zirconia, lithium disilicate, and cobalt chromium alloy were used as superstructure materials. Vertical loads of 100 N and 200 N were applied to the central fossa of the implant-supported prosthesis. The finite element analysis demonstrated that doubling the applied load leads to a proportional increase in von Mises stress on both the implant and bone in a mandibular posterior three-unit implant-supported prosthesis model. Zirconia and chromium cobalt as superstructure materials result in similar stress levels due to their closely matched elastic moduli of 200 GPa and 218 GPa, respectively. In contrast, lithium disilicate leads to the highest stress levels, which is attributed to its lower elastic modulus of 95 GPa. These findings highlight the critical role of superstructure material properties in stress distribution. Zirconia emerges as the preferred material for implant-supported prosthetics due to its favorable stress distribution.