Characteristics of hydroxyapatite films formed on various substrates via hydrothermal reactions of Ca(edta)~(2-) and phosphate

摘要

Hydroxyapatite films were formed on various substrates such as 12 molpercent ceria-doped tetragonal zirconia (12Ce-TZP), 3 molpercent yttria-doped tetragonal zirconia (3Y-TZP), alumina, monetite coated titanium (Ti/CaHPO_4) and calcium titanate coated titanium (Ti/CaTiO_3) via hydrothermal reactions of Ca(edta)~(2-) and 0.05 M NaH_2PO_4 at initial pH 6 and 160 - 120 deg C for 0.5- 6 h. Morphology of the film changed depending on the substrate, i.e. hydroxyapatite entirely coated the surfaces of 12Ce-TZP, Ti/CaHPO_4 and Ti/CaTiO_3 plates, but sparsely deposited on 3Y-TZP and Al_2O_3 plates. Film thickness increased with time (ca. 41 and 90 mu m on 12Ce-TZP for 2 and 6 h, respectively, at pH 6 and 200 deg C). Adhesive strength of the film changed depending on the substrate as 12Ce-TZP(28 MPa)>CaTiO_3 coated Ti (22 MPa)>Ti/CaHPO_4 (9 MPa).