Finite element analysis of bone resorption around dental implant

Previously, a few models have been proposed to predict bone resorption process due to stress shielding in long bones such as proximal femur; however, there are almost no reports on finite element analysis of loss of marginal dental bone that is caused mainly by occlusive overload. In this work, the stress, strain and strain energy density (SED) criteria were separately applied to simulate overload-induced bone resorption in a jawbone/implant system by means of the finite element analysis. A simplified dental bone/implant model was created, with the bone composed of a cortical bone and a cancellous bone and the implant having the detailed screw structure. The results demonstrated that the simulations according to the equal SED criterion reproduce bone resorption patterns that are more realistic to actual clinical situations, when compared to the equal stress or strain criterion. It was shown that bone resorption starts initially in the cortical bone around the implant neck, then extends downwards, and lastly enters the cancellous bone after passing through the interface of the cortical and cancellous bone. A symmetric bone resorption pattern was revealed under the condition of axial loading, whereas an asymmetric resorption prototype was demonstrated under the oblique loading condition. Moreover, in the case of oblique loading, bone resorption is faster and the amount of resorbed bone is larger, which leads to more micromotion of the dental implant than in the case of axial loading.