The influence of the location of load transfer on strains around implants supporting four unit cement-retained fixed prostheses: in vitro evaluation of axial versus off-set loading.

Abstract

Prudent control of the biomechanical load on dental implants is imperative to achieve long-term clinical success. The design of the final prosthesis and location of force transmission have a definitive influence on the quantification of induced strains and load partitioning among implants. While axial loading of implants generate an even distribution of stresses in the bone around implants, off-set loading, which is particularly observed in screw retained prosthesis increases the stresses at the bone-implant interface. This study evaluated the cervical strains on dental implants supporting four unit cement retained fixed prostheses under 50 N static axial and off-set loading conditions. As the type of strains are also dependent on the point of load transfer, design of the prosthesis and implant positioning, the study comprised the evaluation of induced strains through a simulation of five cement retained prosthetic options. The results revealed that off-set loading increases the magnitude of strains. However, it was not significant for all configurations (P < 0.05). This finding emphasizes the accompanying effect of implant location, angulation and macrogeometry of the prosthesis and, that the biomechanical evaluation of affecting factors is a multifaceted phenomenon.