Xylitol, a sugar substitute, has gained attention in the last years due to its antimicrobial, anticaries and remineralizing properties. Thus, effective and safe vehicles are desirable for caries control. Considering that sodium fluoride varnishes are broadly employed in Dentistry to control caries, the present study aims to evaluate the efficacy of a new varnish having xylitol as active principle, in different concentrations, associated or not with fluoride for: 1) in vitro inhibit demineralization and increase remineralization of bovine enamel, 2) on dental enamel de-remineralization in situ and 3) to clinically control active non-cavitated caries lesions (white-spot lesions). For this purpose, in phase 1, the effect of 7 different varnishes (10% Xylitol, 20% Xylitol, 10% Xylitol + 5% NaF, 20% Xylitol + 5% NaF, Duofluoride XII®, Duraphat® and placebo varnish - without xylitol or fluoride) on the inhibition of demineralization and increase of remineralization of sound or artificially demineralized bovine enamel, using an in vitro pH-cycling model will be evaluated (total n = 280 - 20 for each group). In phase 2, 20 will take part in the crossover, split-mouth and double-blind study performed in 4 phases. Four enamel samples will be worn in palatal appliances (2 sound and 2 demineralized), being each type of sample submitted to one treatment: a) Duraphat®, b) xylitol varnish (the one that presents the best result in phase 1), c) 5% NaF xylitol varnish (the one that presents the best result in phase 1) and, d) placebo (without xylitol or fluoride). Finally, in phase 3, 120 6-12-year-old schoolchildren presenting active non-cavitated caries lesions will receive 4 applications with one-week interval, of one of the varnishes evaluated by in situ study. The examination of caries lesions at baseline and at the end of the study will be done using the QLF system (F and lesion area), associated with clinical examination (Nyvad index). Data will be tested for normality and homocedasticity for selection of the appropriated statistical test to be used. The significance level will be set at 5%.
News published in Agência FAPESP Newsletter about the scholarship: