Affiliations: Department of Dental Materials Science and Technology, Osaka University Faculty of Dentistry, Osaka 565, Japan, Tel.: +81 6 879 2919; Fax: +81 6 879 2832 | Department of Ultrastructural Science, Tokyo Dental University, Chiba 261, Japan
Note: [] Corresponding author: Masayuki Okazaki, Department of Dental Materials Science and Technology, Osaka University Faculty of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565, Japan.
Abstract: The partially substituted fluoridated apatites H-FHAp0.5 and FH-HAp0.5 were synthesized heterogeneously by supplying fluoride at a concentration equivalent to half of the maximum value of fluorapatite during the initial or final half of the experimental period. Although X-ray diffraction patterns and SEM photos of H-FHAp0.5 and FH-HAp0.5 apatites were not significantly different, high-resolution transmission electron microscopy showed quite different features; H-FHAp0.5 type apatite was an elongated hexagon with electron beam damage in the core, and FH-HAp0.5 type apatite was a rather wide hexagon analogous to fluorapatite. Energy dispersive spectroscopy attached to the SEM showed H-FHAp0.5 apatite to have a higher fluoride peak intensity than FH-HAp0.5. These results supported the previ6us speculations on the two different types of heterogeneous fluoridated hydroxyapatites: hydroxyapatite covered with fluorapatite and fluorapatite coverted with hydroxyapatite.
