Enamel Protection Superiority of SnF2 vs. Prescription Level Fluorides

While OTC products sold in the U.S. are generally restricted to containing only 1000-1100ppm Fluoride(F), prescription level products often contain 5000ppm F. Some researchers believe that since F in general provides a low level of benefit to the enamel against external acid attack, more F likely works even better. Objectives: The purpose of this study was to determine the relative ability of various F-containing products to protect enamel against the initiation and progression of enamel surface damage due to acid challenges. Methods: Cores of enamel were removed from extracted human teeth, cleaned, lightly ground and polished to provide an essentially virgin enamel surface, soaked in pooled human saliva (pellicle formation), then treated in a 1:3 slurry (product:saliva) of product representing both OTC level (1100ppm) and prescription level(5000ppm) of F. Products compared included: a) 1100ppm F as NaF; b) 1100ppm F as SnF2; c) 5000ppm F as NaF; and d) 5000ppm F as NaF + acidulated phosphate. Specimens were subjected to pH cycling conditions in which the specimens were exposed to a 1% citric acid solution (pH 2.4) over the course of 5 days of treatment, representing challenges to the enamel by a common food based acid. Results: Specimens treated with 1100ppm F (SnF2) toothpaste demonstrated significantly less damage (p=0.05, ANOVA) as a result of this citric acid challenge, losing, on average, only 8.0um of enamel. The 1100ppm F as NaF treated specimens suffered 22.8um of enamel loss, the 5000ppm F as NaF lost 20.0um of enamel and the 5000ppm F as NaF + acidulated phosphate lost an average of 24.0um enamel. Conclusion: Results from this study demonstrated 1100ppm F as SnF2 provides superior protection against common acid attack compared to some of the most popular prescription level fluoride treatments.