Effect of titanium tetrafluoride/sodium fluoride solutions containing chitosan at different viscosities on the protection of enamel erosion in vitro.

OBJECTIVE: The aim of this in vitro study was to evaluate the protective effect against enamel erosion of experimental solutions containing TiF(4)/NaF and Chitosan compared to a commercial SnCl(2)/NaF/AmF solution. DESIGN: Bovine enamel samples were divided (n = 15/group) into: (1) commercial solution SnCl(2)/NaF/AmF (500 ppm F(-), positive control); (2) NaF/TiF(4) (490 ppm F(-)); (3) similar to 2 plus 0.5 % chitosan (Ch) (500 mPas), (4) similar to 2 plus 0.5 % chitosan (2000 mPas), (5) negative control (water), (6) 0.5 % chitosan (500 mPas) and (7) 0.5 % chitosan (2000 mPas). The samples were submitted to a pH cycling (0.1 % citric acid, 4 x 90 s/day, interposed by artificial saliva) and daily treatment application (after the last erosive challenge, 1 x 30 s/day) for seven days. After the first day, the surface reflection intensity changes (% rSRI) were measured. After 7 days, the erosive enamel loss was quantified by contact profilometer. The % rSRI and the enamel loss (mum) were compared using ANOVA/Tukey and Kruskal-Wallis/Dunn, respectively (p < 0.05). RESULTS: The solution containing TiF(4)/NaF plus Ch 500 mPas was the only able to reduce the early erosive demineralization compared to negative control (p = 0.003). However, it did not differ from the other solutions. Enamel samples treated with SnCl(2)/NaF/AmF presented the lowest median loss value [0.72 (0.18) mum] followed by both TiF(4) + Ch [1.24 (0.49) and 1.28 (0.25)]; which significantly differed from the negative control [1.70 (0.27)]. CONCLUSION: The experimental solution containing TiF(4)/NaF plus chitosan (2000 mPas) has comparable effect to SnCl(2)/NaF/AmF on the protection against enamel erosion.