Abstract
Tooth enamel is mainly constructed by hydroxyapatite (HAp) crystals. Since HAp has crystalline structure, X-ray diffraction method can be applied to measure the lattice strain of HAp. In this study, the X-ray diffraction method was applied to the HAp of tooth enamel to obtain the strain of tooth. Column shaped specimens of human teeth were prepared from an incisor tooth and a posterior tooth. The (002) and (004) lattice planes were strongly oriented to the surface perpendicular direction of the tooth. The strain measurements were conducted under the compression of 0.2% strain measured by strain gage. The strains of (004) lattice planes were measured at the several positions on the side surface of tooth specimens. The lattice strains were obtained as tensile strain in the incisor tooth specimen. In the case of posterior tooth specimen, the strains were different values changed in tensile to compressive states by measurement positions.
