Analytical and numerical analysis of human dental occlusal contact

The knowledge of contact forces in teeth surfaces during mastication or para-functional movements can help to understand processes related to friction and wear of human dental enamel. The development of a numerical model for analysis of the occlusal contact between two antagonistic teeth is proposed, which includes three basic steps: the characterisation of the surface roughness, its homogenisation using an assumed distribution function and the numerical determination of the resulting forces. Finite element strain results for the main different asperities are statistically combined, deriving the predicted macroscopic behaviour of the interface. Axisymmetric and 3D numerical models with an elasto-plastic constitutive law are used to simulate micro-indentations and micro-contacts, respectively. The contact is allowed to occur locally in planes not necessarily parallel to the surface's mean plane, a problem for which there is no analytical solution. The three identified parameters, homogenised surface hardness (3.68 GPa), surface yield stress (3.08 GPa) and static friction coefficient (0.23), agree with the experimental values reported in the literature.