A model for the implant-bone interface characteristics of porous dental implants.

The use of computer-aided design techniques, such as finite element stress analysis, to evaluate implant designs requires that the mechanics at the interface between the implant and the bone be characterized. This problem is accentuated when implants designed to achieve stabilization by tissue growth into porous coatings are used. A model has been developed to represent the mechanical properties of the porous material-bone interface. The model, which accounts for the mechanics of bone tissue grown into a porous implant surface, was also developed so that it could be incorporated into a three-dimensional finite-element analysis. The analytical results from a three-dimensional finite-element model of a cylindrical porous rooted dental implant system incorporating the interface model were compared to the results of mechanical tests performed on similar implants which had resided in canines for two yr. The results from the finite element analysis using the interface model were found to be in better agreement with the experimental results than when a direct bone-to-porous-material interface was assumed.