An Intra-Oral Erosive Study to Evaluate High Fluoride Varnish

Objectives: Investigate the step height change using a high fluoride varnish on enamel using an Intra-oral enamel erosion clinical study.
Methods: Twenty-four healthy volunteers, 2 males and 22 females aged 27 - 54 years, were screened and recruited. Panelists wore a palatal splint containing 8 human enamel specimens and each underwent two 3-day treatment periods for 6 hours a day. A varnish containing sodium fluoride at 22,600 ppm and a matching placebo without fluoride, were applied on to the surface of the enamel samples on day 1 in randomized order, removed after 6 hours, then immersed ex-vivo in a pH 2.7 citric acid solution for 2 minutes. The acid cycling was repeated 4 times a day for a total of 2 days. Measurements of enamel were assessed blindly by microhardness on day 2 and by non contact laser profilometry on day 3 for the two treatments. Between product differences were assessed by analysis of variance (ANOVA). For microhardness, the change from baseline (delta) calculated as baseline minus post day 2 was analyzed. An ANOVA product p value of < 0.05 indicates statistical significance.
Results: The delta microhardness for the control and fluoride treatment was 95.7 (22.9) kgf/mm² and 123.7 (28.9) kgf/mm², respectively (p < 0.001). The mean (SD) enamel surface loss for the control was 3.67 (2.07) µm and 1.79 (1.01) µm for the fluoride varnish. The enamel loss for the control was significantly greater than the fluoride varnish (p < 0.001)
Conclusions: Utilizing an intra-oral model where enamel was exposed to acid over the course of 2 days, it was demonstrated that a high fluoride varnish containing sodium fluoride at 22,600 ppm can prevent erosive wear compared to a placebo