A new experiment to determine intrisic thin film PMMA precoated implant/bone cement interface strength under mixed ladings

摘要

Three kinds of expeirments are usually used to estimate the mechanical strenth of PMMA thin film precoated implant/ bone cement: push-out (or pull-out), tensile and torsional tests. But the non-uniformity of the stress state along the specimen interface, the existence of stress singularities and the dependence of results on boundary conditions make the experiments cited unable to provide intrinsic interface s trength values. Morecover, it is important to highlight the fact that they only concern pure loadings. A new experiment has been developed which measures the PMMA precoated implant/bone cement interface intrinsic strength under mixed loadings. The specimen geometry has been optimsed to ensure a uniform and non-singular stress state on the whole ested interface irregarless load. The results concerning 20 #mu# m PMMA thin film precoated Cr-Co-Mo alloy implant/bone cement interface strength are presented.