Method: Fourteen volunteers participated in this hybrid split-mouth parallel study wearing a palatal device containing 4 sterilized bovine enamel slabs, for 10 days. Half of the participants followed protocol A: daily rinse with a Ca lactate solution (150mmol/L, 1min), followed by NaF solution (12mmol/L, 1min), while the other half followed protocol B: daily rinse only with the NaF solution. Appliances were removed from the mouth and one side of the palatal appliance was exposed to an erosive challenge (0.05M citric acid, 90s); the other side served as negative control (no erosion). Specimens were evaluated for wear depth with an optical profilometer (micrometers).
Result: Kruskal Wallis (p=0.003) and Dunn test showed that when Ca+NaF were used prior to erosive challenges, enamel wear (median=-0.02) was similar to that obtained for uneroded groups. Rinse with NaF only resulted in the highest wear (median=-2.27).
Conclusion: Pre-rinse with Ca lactate may increase the protection exerted by NaF against erosion.