Efeito da nano-hidroxiapatita associada ao fluoreto na prevenção da desmineralização do esmalte adjacente aos braquetes ortodônticos : "Estudo In Situ"

Abstract

This in situ study aimed to evaluate the effect of nano-hydroxyapatite associated with fluoride in the prevention of enamel demineralization adjacent to orthodontic brackets. 120 bovine enamel blocks (5x5x2mm) properly polished, were mounted on palatal devices containing three specimens for each side, in two distinct rows. Orthodontic brackets were bonded in the center of each block enamel, set with wire niti 0.016 "and elastic bandages. The experiment was conducted in two stages of 14 days each. During periods of the experiment was dropped 20% sucrose 8 times a day over the enamel blocks for biofilm formation. In the first stage (control groups with and without disruption of the plate), after 7 days, half of the blocks were performed plaque disruption by means of a microbrush. In the second stage of the experiment (group Nano-P), new blocks were positioned on the device and the product was applied Desensibilize ® Nano-P (FGM) at baseline and after 7 days. After the experimental period, the specimens were sectioned in its center, with one half used for analysis by polarized light microscopy, whereas the other half analyzed the microhardness of the enamel, applied in three different distances (bottom bracket, 30 μm and 130 μm from the edge of the bracket) in 7 different depths (10, 20, 30, 50, 70, 90 and 110 μm). Data was analyzed statistically (ANOVA, p <0.05). Considering the groups was observed averages demineralization different, with lower average for the Nano-P group (20.23 μm) when analyzed by polarized light. In the analysis of longitudinal microhardness was observed in relation to distance below the bracket, which was no statistical difference between the control group and Nano-P without disorganization of the plate. In comparison to 30 μm (depths of 10 and 20 μm) and the 130 μm (to a depth 70 μm) Nano-P group significantly increased hardness compared to the others.: Therefore, products containing nano-hydroxyapatite associated with fluoride showed preventive effect on enamel adjacent to orthodontic brackets, could be an alternative treatment for patients at high risk for dental caries.