The Effect of Varying Abutment Heights on Stress Distribution in Different Bone Densities: A Finite Element Analysis Study

TL;DR

This study uses computer modeling to show that taller dental implant abutments increase stress on surrounding bone, especially in softer bone types, which could lead to mechanical issues.

Contribution

The study introduces a finite element analysis to evaluate how abutment height and bone density jointly affect stress distribution in dental implants.

Findings

Higher abutment height increases stress on implants and surrounding bone.

Peak stresses exceeding 300 MPa were observed at the implant-abutment connection.

Stress levels were highest in low-density bone with a 6 mm abutment (126 MPa).

Abstract

The biomechanical performance of dental implants is affected by both abutment height and bone quality, which influence stress distribution around the implant and the preservation of surrounding bone. This study used three-dimensional finite element analysis (FEA) to assess the combined effects of these factors. Two implants with abutment heights of 3 mm and 6 mm were modeled and placed in mandibular bone blocks representing class II and class IV bone, according to Lekholm and Zarb’s classification. A static load of 150 N, inclined at 6° buccolingually, was applied during the analysis. The simulation results showed that increasing the abutment height raises stress on the implant, leading to greater stress transfer to the peri-implant bone. The von Mises stress levels were higher in the crestal cortical bone of the class IV model with a 6 mm abutment (126 MPa). Notably, peak stresses exceeding 300 MPa were localized at the implant-abutment connection. These findings suggest that abutment height is a critical factor that negatively affects the biomechanical response, especially in low-density bone, although longer abutments offer biological benefits. This highlights the importance of minimizing the crown-to-implant ratio to reduce overload, preserve bone, and prevent mechanical failure complications.

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