Ingestão de fluoreto por pré-escolares, com o uso de dentifrícios infantil e regular: um estudo experimental cruzado

Abstract

This study aimed to compare the dose and amount of fluoride (F) ingested through dentifrices formulated for children (childrens) with those formulated for adults (regular), using the Total Fluoride (TF) and Total Soluble Fluoride (TSF) as indicators. Moreover, it aimed to evaluate the TF, FST, and Ionic Fluoride (IF) concentrations in dentifrices regularly used by children. This research used an experimental crossover study in which all children brushed their teeth twice one using a childrens dentifrice and the other using a regular dentifrice on distinct occasions and in their own schools. This study consisted of 197 children from the city of Montes Claros, Minas Gerais, Brazil, from 9 to 48 months of age. The residues left after brushing were collected to determine the amount of F intake during brushing (initial quantity on the brush minus the remainder on the brush and expectorated products) and the F dose (mgF/Kg weight/day) to which the children had been submitted (amount of F intake during brushing multiplied by the number of times the child brushed his/her teeth daily divided by the childs weight). The F content in the residues left after brushing, as well as in the dentifrices used by the children, was determined using a fluoride ion specific electrode. The children were weighed and the parents answered a questionnaire in an attempt to assess the childrens tooth brushing habits and their socioeconomic status (SES). For statistical analysis, Microsoft Office Excel 2007 and the SPSS for Windows, version 18.0, considering p0.05, were used. It could be observed that 45.15% referred to regular dentifrices (100% with 1100-1500 ppmF), while 54.85% referred to childrens dentifrices (86.73% with 1000-1200 ppmF, 5.31% with 500-800 ppmF, and 7.96% without F). The TF concentrations, claimed by the manufacturer and analyzed in this study, were similar, whereas the TSF concentration varied from 422.3 to 1432.3 ppmF (1016.7±234.7 ppmF). The regular dentifrices containing calcium carbonate (CaCO3) as an abrasive, as compared to those found in the childrens dentifrices containing silicon as an abrasive, presented a greater percentage of insoluble F and similar average concentrations of soluble F (1006.3±137.0 and 1061.4±270.3 ppm F, respectively). As regards the type of dentifrice used and the familys SES, a statistically significant relation between the children who used the childrens dentifrice and a high SES, and those who used regular dentifrice and a low SES (p<0.001), could be observed. The TF intake was greater for the regular dentifrice (0.51±0.44 mgF) than for the childrens dentifrice (0.35±0.34 mgF). By contrast, the TSF intake was greater for the childrens dentifrice than for the regular dentifrice (0.37±0.36 and 0.26±0.30 mgF, respectively). Likewise, the F dose to which the children had been submitted also proved to be greater when using the childrens dentifrice than when using the regular dentifrice (0.049±0.068 and 0.034±0.053 mgF/Kg/day, respectively) (p<0.001). Although both types of dentifrice used represent the risk of developing dental fluorosis, it could be observed that the childrens dentifrice brought about a greater TSF intake. Thus, the amount of soluble F, and not only that of the TF, present in the dentifrice should be taken into consideration when estimating the anticaries potential or the risk of developing dental fluorosis.