Functionally graded fluoridated apatites
| Autor: | Takuya Matsumoto, Junzo Takahashi, Yasuo Miake, Hisako Tohda, Masayuki Okazaki, Takaaki Yanagisawa |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Materials science
Scanning electron microscope Biophysics Mineralogy Bioengineering Crystallography X-Ray Electron spectroscopy Apatite Biomaterials chemistry.chemical_compound Solubility Hydroxyl Radical Fluorapatite Buffer solution Microscopy Electron Models Chemical chemistry Mechanics of Materials Transmission electron microscopy visual_art Microscopy Electron Scanning Ceramics and Composites visual_art.visual_art_medium Thermodynamics Hydroxyapatites Fluoride Nuclear chemistry |
| Zdroj: | Biomaterials. 20:1421-1426 |
| ISSN: | 0142-9612 |
| DOI: | 10.1016/s0142-9612(99)00049-6 |
| Popis: | Fluoridated hydroxyapatite was synthesized at 80 +/- 1 degree C and pH 7.4 +/- 0.2 using a gradient fluoride supply system. X-ray diffraction analysis showed a typically apatitic pattern, although the (3 0 0) reflection was broader than that of homogeneous fluorapatite. Scanning electron micrographic observation indicated that the apatite was composed of rod-like crystals similarly to fluorapatite. High-resolution transmission electron microscopy showed electron damage in the core of the crystal. When the apatite pellet was prepared, electron spectroscopy for chemical analysis showed a negative gradient of fluoride concentration with depth in the crystals. The apparent 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 hydroxyapatite 32.3 +/- 1.9 mmol/l, and less than that of heterogeneous two-layer fluoridated apatite with an outer fluoride-rich layer 12.5 +/- 0.6 mmol/l, which was synthesized previously by supplying fluoride during the latter half of the experimental period. These results suggest that graded fluoridated apatite may be formed by this process and have higher acid resistance than two-layer fluoridated apatite. |
| Databáze: | OpenAIRE |
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