Histidine buffering of acidic fluoridated solutions increases CaF<sub>2</sub>-like formation on carious enamel

Aim: Since the reactivity of fluoride with enamel decreases when the pH of slightly acidic solutions is not maintained, we evaluated the effect of acidic fluoridated solutions buffered with histidine on the formation of loosely (CaF2-like) bound products on enamel. Methods: Demineralized enamel slabs were treated with 0.05% NaF solution at pH levels of 5.0, 5.5, 6.0, and 6.5, either buffered or not with histidine (n=12). CaF2- like product formation was determined in enamel, and the data were submitted to ANOVA, Tukey, and Dunnett’s tests. Results: Buffered fluoride solutions, regardless of pH, formed higher concentrations of CaF2-like products on enamel than the respective group without buffering (p<0.05). Conclusion: The findings show that the buffering increases CaF2-like formation on carious enamel, although a direct effect of histidine cannot be entirely ruled out.