Is Fluoride Concentration in Dentin and Enamel a Good Indicator of Dental Fluorosis?

Abstract

Despite some studies correlating dental fluorosis (DF) and fluoride (F) concentration in dental enamel, no information is available about DF and dentin F concentration. Our objective was to determine the correlation between teeth F concentration and DF severity in unerupted human 3rd molars, and the correlation between dentin and enamel F concentrations in the same tooth. Ninety-nine 3rd molars were studied—53 from Fortaleza, Brazil (F water, 0.7 ppm), 22 from Toronto (1.0 ppm), and 24 from Montreal (0.2 ppm). DF severity was evaluated according to the Thylstrup-Fejerskov Index, while F concentration was analyzed by Instrumental Neutron Activation Analysis. DF severity varied between TF0 and TF4, while F concentration ranged between 39 and 550 ppm in enamel and 101 and 860 ppm in dentin. Our results showed correlation between dentin F concentration and DF (rS = 0.316, p = 0.001), but no correlation between enamel F concentration and DF (rS = 0.154, p = 0.133). No correlation was observed between dentin and enamel F concentrations in the same tooth (rS = 0.064, p = 0.536).