The influence of implant geometry on the stress distribution around dental implants.

A three-dimensional finite element stress analysis has been used to investigate the influence that variations in the infrastructural geometry of a blade-type dental implant have on the stress distribution around LTI carbon and aluminum oxide implants. The finite element model was constructed based upon an analysis of serial sections of a retrieved implant specimen. In addition to the implant, the finite element model contained a three-unit fixed bridge connected to a natural molar with periodontal membrane. The removal of the bridge allowed for the study of freestanding implants and molar. Variations of the implant blade geometry were found to produce significant changes in the stress distributions around bridged and freestanding aluminum oxide implants. Very little effect, however, was observed around the LTI carbon implants. A comparison of the stresses around the freestanding molar and the stresses around the bridged and freestanding implants was made to determine the implant design that came closest to reproducing the stress state around the modeled molar. The LTI carbon system that best achieved this stress state was found to be a full-blade implant used in conjunction with a tooth as an abutment in a fixed bridge. The aluminum oxide system that best achieved this stress state was found to be of the post or short-blade design used as a freestanding implant.