Methods: this study was performed using 3D finite element analysis. Twelve models were compared using three different lengths (12, 10 and 8mm) and two different diameters of implants in titanium (4 and 5 mm). Each of the 6 implants carried an abutment in titanium and was connected to a tooth by a ceramic prosthesis. Two prosthetics configurations were considered: two connected crowns and a 3 unit Fixed Partial Denture. The implant and the tooth were seated in a supporting structure of cancellous bone. A vertical occlusal load of 100 newtons is applied in the middle of the prosthesis.
Results: Whatever the shape of the implant, it acted like the fulcrum of a device that induces the intrusion of the tooth. Bone stresses appear around the neck of the implant. In implants and abutments, stresses are meaningfully less intense when the diameter was 5 mm and when the distance between the tooth and the implant decreases. Implant length is a less influencing parameter.
Conclusion: If implant abutments and natural teeth are involved to support a prosthetic restoration, the use of wide-bodied implants in selected cases of short-span fixed partial dentures is recommended. Nevertheless, bone quality and methods of connection are important parameters that must be studied and taken into account