Contact induced deformation of enamel

Teeth survive millions of contact cycles with relatively limited damage and wear, despite high local contact stresses. In this letter, the authors investigated the influence of enamel microstructure and specifically the role of the minor protein component on contact induced deformation. They assume that protein is responsible for the nonlinear contact stress-strain relationship. The extremely low contact stresses to induce inelastic contact deformation result in high contact induced energy loss which is indenter geometry dependent. A simple model shows that shear strain in protein layer is 16 times higher than the contact strain, and is where most deformation is dissipated. (c) 2007 American Institute of Physics.