Effect of 0.02% NaF solution on enamel demineralization and fluoride uptake by deciduous teeth in vitro Efeito da solução de NaF a 0,02% na desmineralização e incorporação de fluoreto pelo esmalte de dentes decíduos in vitro

INTRODUCTION Fluoride dentifrice is considered an important factor in explaining the decline in dental caries observed either in developed or in developing countries at the end of the last century. However, fluoride dentifrice is also a risk factor with respect to dental fluorosis because young children ingest a large amount of toothpaste during brushing. In addition, there is evidence that dental fluorosis is increasing in developed countries irrespective of whether the areas concerned have water fluoridation or not. These findings in developed countries are an alert to developing countries that have caries control programs based on fluoride use. In order to reduce the risk of dental fluorosis some recommendations have been made for young children: (i) do not use dentifrice, or use a non-fluoride dentifrice; however, the presence of fluoride during toothbrushing is considered indispensable; (ii) use a dentifrice with low fluoride concentration; however, the anticaries effect of dentifrice with less than 1,100 μg F/g is not well-established; (iii) use a small amount of dentifrice; however, the anticaries effect of this procedure has not yet been established. In addition to these international recommendations, the use of 0.02% NaF solution for children under 3 years of age in Brazil has been suggested, instead of fluoride dentifrice. Parents or guardians should apply this solution to the children’s teeth daily, using a cotton swab. This alternative is safer than the use of fluoride dentifrice with regard to dental fluorosis because the child is subjected daily to a low amount of fluoride (approximately 0.01 mg F/cotton swab). However, its anti-caries potential is unknown. Thus, the aim of this study was to evaluate