Stress Distribution on Short Implants at Maxillary Posterior Alveolar Bone Model with Different Bone-to-Implant Contact Ratio: Finite Element Analysis

Abstract

The aim of this study is to evaluate the stress distribution of the short dental implants and bone-to-implant contact ratios in the posterior maxilla using 3D finite element models. Two different 3D maxillary posterior bone segments were modelled. Group 1 was composed of a bone segment consisting of cortical bone and type IV cancellous bone with 100% bone-to-implant contact. Group 2 was analoged as a bone segment consisting of cortical bone and cancellous bone including spherical bone design and homogenous tubular hollow spaced structures with 30% spherical porosities and 70% bone-to-implant contact ratio. 4 mm diameter and 5 mm height dental implants were assumed to be osseointegrated and placed at the center of the segments. 300 N lateral occlusal bite force was applied at a 25 degree inclination to the implants long axis. The maximum von Mises stresses in cortical and cancellous bones; and implant-abutment complex were calculated. The von Mises stress values upon the implants and the cancellous bone around the implants of the 70% bone-to-implant contact group were almost three times higher compared to the values of the 100% bone-to-implant contact group. For clinical reality, use of the 70% model for finite element analysis (FEA) simulation of the posterior maxilla region better represents real alveolar bone and the increased stress and strain distributions evaluated on the cortical and cancellous bone around the dental implants.