Atmospheric plasma spraying of hydroxyapatite was carried out to investigate the influence of the plasma spraying parameters on the formation of the amorphous phase. The amorphous phase was investigated with X-ray diffraction and optical microscopy. The results infer that dehydroxylation of the molten particle and a high cooling rate produce a larger amount of the amorphous phase. Crystalline regions of the coating consist of partially molten particles and elongated recrystallized areas. The amorphous phase is commonly found at the substrate interface. It is shown that the amorphous regions vary throughout the coating which clinically could affect the process of bone deposition and successful implant fixation.
Bioceramics: proceedings of the 8th International Symposium on Ceramics in Medicine, Ponte Vedra, Florida, United States, November 1995 / June Wilson, Larry L. Hench and David Greenspan (eds.),
Vol. 8, pp. 361-366