An in vitro evaluation of the strength of a 1-piece and 2-piece conical abutment joint in implant design.

The performance and maintenance of implant-supported prostheses are primarily dependent upon load transmission both at the bone-to-implant interface and within the implant-abutment-prosthesis complex. The design of the interface between components has been shown to have a profound influence on the stability of screw joints. In this in vitro evaluation, implants utilizing an internal conical joint have demonstrated a parity in resistance to bending moments at the fixture-abutment interface, when comparing a 1-piece abutment to a 2-piece abutment, which is tightened via a separate abutment screw, with mean plastic bending moments of 4176 N mm and 4049 N mm respectively. The very small values for coefficient of variance measured in both systems would confirm that whilst the size of data is small it is nonetheless a reliable indication of the relative strength of these conical joint designs.