The protective effect of SnF2 containing toothpastes and solution on enamel surfaces subjected to erosion and abrasion in situ

Stannous fluoride solutions have shown promising protective effect against erosion/abrasion, but the effect of SnF2 toothpastes is uncertain. The aim of the study was to test the inhibiting effect of two SnF2 toothpastes and a SnF2 solution against erosive/abrasive wear in a single-blind, randomised in situ study, using a white light interferometer. Sixteen human molars were each divided into four specimens, mounted on mouth appliances and worn by 8 volunteers for 9 days. Specimens were brushed with toothpaste twice each day for 30 s either with fluoride-free toothpaste or toothpastes including SnF2. Toothpaste was left on the surface for 90 additional seconds. Group 1, fluoride-free toothpaste; Group 2, toothpaste A (0.4 % SnF2, Solidox); Group 3, toothpaste B (0.454 % SnF2, Oral-B®); Group 4, brushed with fluoride-free toothpaste (30 s) and treated for 2 min with a 0.4 % SnF2 solution (1,000 ppm F). To mimic gastric reflux/vomit, specimens were etched for 2 min twice a day (0.01 M HCl). Procedures were performed extra-orally. The mean enamel wear (in μm) for the control specimens was: −29.2 ± SD 10.5; for group 2 −14.5 SD ± 9.3; for group 3 −33.3 SD ± 7.4, and for group 4 +0.4 SD ± 1.3. The specimens treated with SnF2 solution and toothpaste A showed significantly lower enamel wear than the control group. Toothpaste B gave no significant reduction in enamel wear. The SnF2 solution fully protected the enamel surface against erosive and abrasive challenges. The SnF2 toothpaste A (Solidox) showed less, but significant protection of the enamel, while no statistically significant protection was demonstrated by SnF2 toothpaste B (Oral-B® Pro-Expert).