Biomechanical evaluation of splinted 4- and 6- millimeters short dental implants with different crown-implant ratios, a finite element analysis

Abstract

The purpose of this study was to assess the influence of the crown height, and the crown to implant ratio, of two adjacent 4- and 6-millimeters short dental implants with connected and non-connected restorations on the distribution of stress to the implant abutment and periimplant structures, using a three-dimensional finite element method. Dental implants and abutments were scanned, and the scans were analysed using NX Nastran software to create finite element models. A total of 48 experimental states from 12 finite element models were initiated with different conditions according to diameter, length, crown height, and direction of the occlusal force. The results showed that crown height did not influence the stress concentration on implant abutment and surrounding bone under axial (90?) loading, while oblique (45?) loading strongly influenced the outcome. Increasing the crown to implant ratio from 1:1 to 2:1 resulted in increasing stress values 22.38-76.78%. The results of this study suggest that connecting two restorations does not have significance difference on stress distribution to implant. In splinted models, stress tends to concentrate on outer implant fixtures and peri-implant structures.