2019 年 28 巻 2 号 p. 165-174
Fundamental studies on biocompatible materials were conducted using the mechanism of dentin formation as a model. Hydroxyapatite and fluorinated apatite were synthesized in a gelatin solution. Synthesized apatite was pressed under vacuum, and the mechanical strength was investigated. A hardened mold was prepared by adding amorphous calcium phosphate (ACP). Then, changes in the crystals of the hardened mold dipped in distilled water or 1 ppm fluoride solution were observed with a transmission electron microscope. The results showed that the crystal growth of apatite synthesized in 1% gelatin was suppressed. Moreover, small and homogenous granular apatite was formed in the precipitate synthesized with fluorine. Gelatin contributed to the reduction of brittleness of the hardened mold, and thus a high cutting resistance value was obtained. Furthermore, acceleration of crystal growth and aggregation of fine crystals were observed in the hardened mold when ACP was added to the solution.