Three Dimensional Finite Element Analysis Of Stress Distribution Of Implant-abutment Interface

The stability of the implant-abutment joint is one of the key factors which are critical to the success of implant restoration. The different interfaces of the implant-abutment joint would cause different degree of rotation of the joint, and the less degree of rotation is , the lower potential micromotion of the interface would be, thus reducing the degree of rotation would benefit to the long term stability of the implant-abutment joint. Researches have indicated that the Spline implant system is a system with mechanical stability and low degree of rotation, yet there is still no report on the comparison between the Spline implant system and other implant systems. This study is a part of series studies of the Spline implant system, which is aimed at comparing stress distribution of the implant-abutment joint of the Spline and other implant systems under different loads, thus provides theory basis for further investigation and improvement of the Splineimplant system.This study uses the method of three-dimensional finite element analysis. The three-dimensional models of different implant-abutment joint, which are of the same length and dimension, are modeled by software Pro/Engineer Wildfire 2.0, and the finite element analysis is based on Ansys Workbench 9.0.In this research, we find that under different external loads, the Spline system has different stress distribution compared with implant systems with external-hex, internal-hex and Morse Taper connections. Maximum Von Mises stress of central screw locates at the joint of the screw head and the screw shank. Maximum Von Mises stress of the Spline implant locates at the root of the Spline projections. Lateral load causes dramatical increase of the stress of the implant-abutment joint. Maximum stresses of different implant-abutment joint are all within the yield stress of the material.From the mechanical point of view, it is concluded that the weakness part of the Spline implant is the root of the Spline projections, the central screw of the Spline system plays a role in protecting the implant and abutment. Lateral load would increase the stress of the implant-abutment joint dramatically, thus it is recommened to diminish the lateral stress when making clinical designs in order to ensure the stability of the implant-abutment joint.