The effect of a tannin-fluoride mixture on human dental enamel.
In this study, the effect of a tannin-fluoride mixture (Ta-F, 0.5% tannic acid, 450 ppm fluoride, pH 5.9) on dental enamel has been investigated by using scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and X-ray diffraction (XRD), compared with the effect of acidulated phosphate fluoride (APF, 0.015 M phosphoric acid, 450 ppm fluoride, pH 5.3). Under the SEM, a large number of spherical globules (1-5 microns in diameter) were observed on the enamel surface treated with Ta-F. On a fractured cross section, these large globules showed a columnar appearance, measuring 2.5-5 microns each in height. They had a good range and formed a single coating layer on the enamel, whereas on the APF-treated enamel only very small spherical globules 0.1-0.5 micron in diameter were seen. Moreover, three types of connective patterns were observed between the basal ends of these columnar deposits and the enamel surface: (a) a pattern loosely attached to the enamel surface, (b) a pattern partially connected with the crystals of enamel, and (c) a pattern inserted into the pores of enamel. These columnar deposits also showed very strong resistance either to acid decalcification or to water washing. By EPMA and XRD examinations, a remarkable elevation of the fluoride profile accompanied by a high elevation of calcium was observed and CaF2 peaks were detected on the enamel surface. These results suggest that the columnar deposits might contain the CaF2-like substances and possess unique morphological and qualitative features which are quite different from the deposits found after APF or NaF treatment as described in previous studies.
Department of Preventive Dentistry, Faculty of Dentistry, Kyushu University, Fukuoka, Japan.
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H
Yu
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Xu
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T
Oho
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T
Morioka
D000134:Acid Etching, Dental; D000149:Acidulated Phosphate Fluoride / Q000494:pharmacology; D002327:Cariostatic Agents / Q000494:pharmacology*; D003743:Dental Enamel / Q000187:drug effects* / Q000648:ultrastructure; D005460:Fluorides, Topical / Q000494:pharmacology*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties / Q000187:drug effects; D013634:Tannins / Q000494:pharmacology*
D002327:Cariostatic Agents; D005460:Fluorides, Topical; D013634:Tannins; D000149:Acidulated Phosphate Fluoride