Effect of acidulated phosphate fluoride – gel and foam – on enamel caries-like lesion of primary teeth: an in vitro study

Abstract

The purpose of this study was to evaluate in vitro the effect of APF, gel and foam, for 1 to 4 minutes, on artificial enamel caries-like lesion of primary teeth submitted to the pH cycling. The specimens with medium values of initial superficial enamel micro-hardness between 272 and 331KHN were selected for the formation of the artificial caries lesion. Later, they were randomly divided into 6 groups (n=15): no pH cycling control, cycled control, gel 1min, gel 4min, foam 1min and foam 4min.The no pH cycling control group was maintained in an humid environment, while the application of APF and the pH cycling were accomplished. After, the specimens were sectioned at the center for the enamel cross-sectional micro-hardness test. The values of micro-hardness of the depths from 20 to 180mm were converted into percentile of mineral volume (%Vol) and the area of mineral recovery (∆ZR) was calculated.  In spite of there is no statistically significant differences, it was observed through the analysis of the ∆ZR a difference in the values for the groups gel 1min and foam 4min (p>0.05). The evaluation of %Vol indicated a significant difference only at 60mm depth (p=0.005). This study concluded that a single application of APF gel or foam, for 1 or 4 minutes, do not remineralize artificial enamel caries-like lesion of primary teeth