Functionally graded fluoridated apatites

Citation
M. Okazaki et al., Functionally graded fluoridated apatites, BIOMATERIAL, 20(15), 1999, pp. 1421-1426
Citations number
29
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Multidisciplinary
Journal title
BIOMATERIALS
ISSN journal
0142-9612 → ACNP
Volume
20
Issue
15
Year of publication
1999
Pages
1421 - 1426
Database
ISI
SICI code
0142-9612(199908)20:15<1421:FGFA>2.0.ZU;2-2
Abstract
Fluoridated hydroxyapatite was synthesized at 80 +/- 1 degrees C and pH 7.4 +/- 0.2 using a gradient fluoride supply system. X-ray diffraction analysi s showed a typically apatitic pattern, although the (3 0 0) reflection was broader than that of homogeneous fluorapatite. Scanning electron micrograph ic observation indicated that the apatite was composed of rod-like crystals similarly to fluorapatite. High-resolution transmission electron microscop y showed electron damage in the core of the crystal. When the apatite pelle t was prepared, electron spectroscopy for chemical analysis showed a negati ve gradient of fluoride concentration with depth in the crystals. The appar ent solubility in 0.5 mol/l acetate buffer solution (37 degrees C and pH 4. 0) was 9.16 +/- 0.39 mmol/l, much less than that of homogeneous hydroxyapat ite 32.3 +/- 1.9 mmol/l, and less than that of heterogeneous two-layer fluo ridated apatite with an outer fluoride-rich layer 12.5 +/- 0.6 mmol/l, whic h was synthesized previously by supplying fluoride during the latter half o f the experimental period. These results suggest that graded fluoridated ap atite may be formed by this process and have higher acid resistance than tw o-layer fluoridated apatite. (C) 1999 Elsevier Science Ltd. All rights rese rved.