Preventive effect of an iron varnish on bovine enamel erosion in vitro

Abstract Objective 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 four groups ( n = 20 per 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 1 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 analysed by profilometry. Data were analysed by ANOVA and Tukey's test ( p < 0.05). Results The mean wear (±S.E.) 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.