Remineralization and acid resistance of enamel lesions after chewing gum containing fluoride extracted from green tea

Background: The aim of this study was to evaluate enamel remineralization and the acquisition of acid resistance by using sugar‐free chewing gum containing fluoride extracted from green tea. Methods: Forty‐five volunteers participated in a crossover, double‐blind study and wore intraoral appliances with human demineralized enamel. Subjects chewed fluoride chewing gum (FCG: 50 μg fluoride) or placebo gum. Remineralization and acid resistance were evaluated using the mineral change value (ΔZ, in vol%·μm). Fluoride concentrations in saliva and remineralized enamel were analysed. Results: The peak salivary fluoride concentration was 3.93 ± 1.28 ppm (mean ± SD). The elevated salivary fluoride concentration resulted in a higher fluoride concentration of 656 ± 95 ppm in the remineralized region versus 159 ± 26 ppm for placebo gum (p < 0.001). After remineralization, the ΔZ of the FCG group was higher than that of the placebo gum group. After an acid challenge, ΔZ of the FCG group was lower than the placebo gum group. Both ΔZ were statistically significant. Conclusions: FCG produced a superior level of remineralization and acid resistance, as compared to the placebo gum. The in situ results suggest that regular use of FCG is useful for preventing dental caries.