Effect of an Iron Varnish on Bovine Enamel Erosion

Objectives: The aim of this study was to evaluate, in vitro, the effect of an experimental varnish containing iron on the dissolution of bovine enamel by carbonated beverage. Methods: Eighty specimens were randomly allocated to 4 groups (n=20/group), according to the following treatments: Fe varnish (FeV, 10 mmol/L Fe), F varnish (FV, 2.71% F), placebo varnish (PV) and control (not treated, NT). The varnishes were applied in a thin layer and removed after 6 h. Then, the samples were submitted to six cycles, alternating re- and demineralisation (only one day). Demineralisation was performed with the beverage Coca-Cola® (10 min, 30 mL/block) and remineralisation with artificial saliva for 1 h. In order to determine the amount of enamel dissolved, the wear was analyzed by profilometry. Data were analysed by ANOVA and Tukey's test (p<0.05). Results: The mean wear (±SE) was significantly lesser for the FeV (0.451±0.018 µm) when compared to the other treatments. The FV caused significantly less wear (0.554±0.022 µm) when compared to PV (0.991±0.039 µm) and NT (1.014±0.033), which did not significantly differ from each other. Conclusions: The results suggest that the iron varnish can interfere with the dissolution of dental enamel in the presence of acidic beverages.