How does fluoride concentration in the tooth affect apatite crystal size?
Despite fluoride's (F) well-documented ability to prevent caries, the effects of F concentrations on enamel and dentin apatite crystals are unknown. The present study examined the hypothesis that tooth F concentration and tooth crystallite size correlate. One hundred human unerupted third molars were studied-53 from Fortaleza-Brazil (F water 0.7 ppm), 23 from Toronto (1.0 ppm), and 24 from Montreal (0.2 ppm). F concentration was analyzed by Neutron Activation Analysis and apatite crystal size by powder x-ray diffraction. A positive correlation between dentin F concentration and enamel crystallite length and width was found. Enamel crystallite length was significantly greater in teeth from Fortaleza than in teeth from Toronto (p = 0.011) and Montreal (p = 0.003). Enamel crystallite widths were significantly greater in Fortaleza teeth compared with those from Toronto (p = 0.020) and Montreal (p < 0.001). No difference in the dentin crystallite size was seen in the 3 regions. Thus, tooth F concentration and crystallite size correlate.
Faculty of Dentistry, University of Toronto, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, ON, Canada.
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Vieira
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Hancock
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Limeback
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Schwartz
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Grynpas
D000704:Analysis of Variance; D001938:Brazil; D002327:Cariostatic Agents / Q000032:analysis*; D003460:Crystallization; D018360:Crystallography, X-Ray; D003743:Dental Enamel / Q000737:chemistry*; D003804:Dentin / Q000737:chemistry*; D005459:Fluorides / Q000032:analysis*; D006801:Humans; D006882:Hydroxyapatites / Q000737:chemistry*; D008963:Molar; D009501:Neutron Activation Analysis; D009864:Ontario; D011792:Quebec; D018709:Statistics, Nonparametric; D014881:Water Supply / Q000032:analysis
D002327:Cariostatic Agents; D006882:Hydroxyapatites; D005459:Fluorides