Principles of deformation resistance in human tooth dentine.
We determined the Young's modulus and Poisson's ratio of apatite nano-particles in dentine. These engineering parameters define the elastic mechanical properties from which the properties of the teeth (and bones) are derived. We have also showen that residual stresses are built into the tooth nanostructures, and they help arrest or prevent cracks from penetrating towards the pulp. Collagen fibers and mineral particles are strongly linked adding to the strength and toughness of the material, something that is yet to be achieved by artificial materials.