Effect of Abutment Height Difference on Stress Distribution in Mandibular Overdentures: A Three-Dimensional Finite Element Analysis

Background and aim: implant-supported overdentures are a treatment option foredentulous patients. one of the important factors in determining the prognosis ofoverdenture treatment is to control the distribution of stress in the implant-boneand attachment complex. this study assessed the effect of implant abutment heightdifference on stress distribution in mandibular overdentures.materials and methods: in this study, three models of mandibular overdentureswere designed independently using finite element analysis (fea). the implantswere placed at different height levels relative to the adjacent implant (1 mm, 2 mmand 3 mm). a 100 n load was applied to the overdenture, and the software wasprogrammed for stress analysis in the models. the load was applied bilaterally,unilaterally, vertically, and obliquely. finally, the von misses stresses wereproduced numerically, color-coded, and compared among the models.results: the models in which the implants had up to 2 mm height difference witheach other showed better stress distribution than the model with 3 mm heightdifference between the implants. in all conditions, the implant neck showed thehighest concentration of stress among all areas of the implant. lower stress levelswere found in the cancellous bone than the cortical bone in different loadingconditions.conclusion: lower von mises stress values were found in the models with up to 2mm difference in implant height, and higher stress values were noted in the corticalbone and the implant neck compared with trabecular bone.