Heterogeneous fluoridated apatites synthesized with a three-step fluoride supply system.
Two types of heterogeneous fluoridated apatite, H-F-H and F-H-F, were synthesized by supplying fluoride during the middle half (H-F-H) or initial and final quarters (F-H-F) of the experimental period. Although X-ray diffraction patterns and SEM photographs of both H-F-H and F-H-F-type apatites were not significantly different, high-resolution transmission electron microscopy showed quite different features; H-F-H-type apatite crystals were elongated hexagons, while those of F-H-F-type apatite were rather wider hexagons with electron damage in three-quarters of the inner core. These results supported the previous speculations on the two different types of heterogeneous fluoridated hydroxyapatites synthesized with fluoride concentrations stoichiometrically equivalent to that of fluorapatite: hydroxyapatite covered with fluorapatite and fluorapatite covered with hydroxyapatite. F-H-F-type apatite was less soluble than that of H-F-H-type apatite.
Department of Dental Materials Science and Technology, Osaka University Faculty of Dentistry, Japan.
M
M
Okazaki
H
H
Tohda
T
T
Yanagisawa
M
M
Taira
J
J
Takahashi
D001031:Apatites / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005459:Fluorides / Q000737:chemistry*; D006882:Hydroxyapatites / Q000737:chemistry; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D012995:Solubility; D013499:Surface Properties
D001031:Apatites; D006882:Hydroxyapatites; C025105:fluorapatite; D005459:Fluorides