抄録
Crystals in tooth enamel were analyzed by X-ray diffraction, XRD, using a 100 μm in diameter microbeam. A polished section of human tooth enamel was made, and the microbeam XRD patterns were obtained at six positions from the enamel-dentin junction region to the surface region. Although the apatite unit cell dimensions of the six positions were almost the same, the orientation of crystallites changed abruptly at the surface layer. It was noted that the crystallites aligned not only in their c-axis but also in their a-axis.