Duplex Prepared Hydroxyapatite Coating and Its Biocompatibility

The hydroxyapatite coating was hydrothermally prepared from plasma sprayed CaHPO4 coating and its bonding strength and solubility were studied. The osteoblast culture test was also produced in order to examine the biocompatibility of the coating. The as-sprayed coating consists of CaHPO4, β-Ca2P2O7 and α-Ca3(PO4)2, and the phase ratio, crystallity and morphology are dependent on spraying current and stand-off distance. The as-spayed coating can be converted to calcium-deficient hydroxyapatite coating with needle-like crystals by hydrothermal treatment. The hydrothermally synthesized hydroxyapatite coating having high bonding strength and stability, possesses good biocompatibility with the osteoblast.