The effect of different implant-bone levels on stress distribution in three-unit monolithic zirconia restorations: A 3D finite element analysis

Aim: The aim of this study is to investigate the stress distribution in implant-supported three-unit monolithic zirconia restorations according to different bone levels at which implants are placed in the mandible, using three-dimensional finite element analysis. Methodology: For this study, mucosal, trabecular, and cortical bone pieces were designed using the SolidWorks program to simulate an edentulous mandibular jawbone. Two implants were positioned in areas numbered 44 and 46 with different subcrestal placements (0 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm). In each model, dental implants, abutments (TiBase), monolithic zirconia crowns, abutment screws, and bone tissues were simulated. The obtained data were exported as Standard Tesselation Language (STL) files and imported into the Exocad program for the design of prosthetic restorations and custom abutments. The STL files were then imported into the Geomagic Design X program to merge the implants, abutments, and restorations on the digital model. The final models were saved as STP files and transferred to the ABAQUS software for finite element analysis. Subsequently, an oblique load of 150 N in the buccolingual direction was applied to the occlusal table for 1000 cycles, and the mandibular jawbone was fully constrained (encastre) in all directions (both movement and rotation). Stress distribution values were recorded in von Mises (vMS) units, and fatigue performances were measured using the Seegers method. Results: As the implant bone levels increased, the vMS increased on the prosthetic restoration. Specifically, vMS increased on the abutment of implant 44 but decreased on implant 46. Fatigue performance worsened on the abutment of implant 44 but improved on the abutment, and screws of implant 46. Abutment screws proved most durable, with abutments experiencing early failures. Conclusion: According to the results of the study, it has been observed that the implant bone level affects the stresses occurring in prosthetic restoration. How to cite this article: Alioğlu Koparal NS, Tunçdemir AR, Demirel MG, Mohammadi R, Keçeci M. The effect of different implant-bone levels on stress distribution in three-unit monolithic zirconia restorations: A 3D finite element analysis. Int Dent Res. 2024;14(S1):81-89 https://doi.org/10.5577/indentres.566