Elastic anysotropy of dentin and enamel

摘要

The anisotropy of the elastic properties of hard tooth tissues, dentine and enamel is investigated. Dentin and enamel are considered as anisotropic hexagonal symmetry media. The variability of Poisson’s ratio for dentin and enamel are obtained is analyzed. The parameters of elastic anisotropy are calculated. These parameters exceed the characteristic boundary values inherent in isotropic materials, including the known composite materials, used in dentistry for restoration. It is assumed that this can lead to the formation of domains of overstress at the border of the filling material-dentin and the filling material-enamel, to accompany the growth of microcracks, to weaken the adhesion of the material to dentin and enamel, to destroy the results of restoration by composite materials. Elastic anisotropy of hexagonal crystals was determined in several parameters, since on the basis of literature data it was assumed that there is no such anisotropy index of the deformation of hexagonal crystals, which could be considered the main one. Orientational dependencies of the elastic moduli are given. The possibility of predicting the "technical" elastic characteristics of microinhomogeneous materials – composites, such as hard tissues of the tooth and bones of the skeleton, is estimated on the basis of measurement and calculation of the elastic parameters of their individual components. It is represented that the obtained data will promote to the best understanding of communications between structure and elastic properties of tissues and optimization of the decision of problems of biomechanics of a tooth taking into account symmetry of their mechanical properties.