Abstract
Growth mechanism of hydroxyapatite crystal under the psudo-physiological conditions was investigated by in situ atomic force microscopy using hydrothermally synthesized single crystal as the seed. It was revealed that the rate determining process of a growth was not in the diffusion process but in the incorporation of a growth unit into the crystal. The relative resistance of incorporation showed a similar value as that of macromolecular protein and virus crystals suggesting that the growth unit of hydroxyapatite was a duster. This cluster may correspond to the "Posner cluster" which was defined in the structure of amorphous calcium phosphate.
