Influence of different diameter reductions in the labial neck region on the stress distribution around custom-made root-analogue implants.

Abstract

This study was designed to investigate the influence of diameter reductions on the stress distribution around root-analogue implants via 3D finite element analysis. Four root-analogue implant models with different diameter reductions (0, 1, 2, or 3mm), a traditional threaded implant and congruent bone models were created through reverse engineering. A 100-N force was applied parallel with and in a 45° angle to the implant axis, respectively. The stress concentration in the labial neck area around implants with 1-2mm diameter reduction was lower than seen with no reduction. When the implant diameter was reduced by 3mm, there were obvious stress concentrations in both implant and bone (the maximum stress was 206 and 111MPa, respectively). In other groups, the maximum stress was 65.1MPa in the bone and 108MPa in the implant. Additionally, the stress concentration in the bone around the root-analogue implant when the implant diameter was reduced by 0-2mm (maximum stress of 65.1MPa) was obviously smaller than that around the traditional implant (maximum stress 130.4MPa). Reducing the diameter of maxillary central incisor root-analogue implants by up to 2mm next to the labial cortical bone could help disperse stress.