ABSTRACT
OBJECTIVE: To evaluate root dentine demineralisation, biomass and loosely bound fluoride (CaF2 ) concentration according to different frequencies of sucrose exposure using a high-fluoride dentifrice. BACKGROUND: Although high-fluoride dentifrice has been recommended to arrest root dentine lesions, it is not clear whether it can protect dentine from increased frequencies of sucrose exposure. METHODS: An in situ, crossover, split-mouth study was conducted in 3 phases with 7 days each, in which 10 volunteers used a palatal device containing 4 bovine root dentine slabs (2 on each side) with predetermined initial hardness. Cariogenic challenge consisted in dripping a 20% sucrose solution 0 (control), 2, 4, 6, 8 or 10 times/d in each block. Volunteers used high-fluoride dentifrice (NaF, 5000 µg F/g) 3 times/d. After each phase, final hardness was measured and the percentage of surface hardness loss (%SHL) calculated. Also, biomass and CaF2 concentration on dentine were determined. The data were processed and analysed by ANOVA and Tukey test with significance level set at 5%. The relationship between the variables was analysed by linear regression and Pearson correlation (r). RESULTS: %SHL and biomass were significantly greater than control for sucrose frequencies higher than 6 times/d (P < 0.001), while CaF2 concentration decreased from sucrose frequency higher than 2 times/d (P < 0.001). Regression analysis data showed a significant linear fit between sucrose exposure frequency and the studied variables with a strong correlation (r) for %SHL and CaF2 and moderate for biomass (P < 0.05). CONCLUSION: High-fluoride dentifrice is able to reduce root dentine demineralisation if sucrose consumption is not higher than 6 times/d.
