EFEITO IN SITU DE AGENTES BIOATIVOS NO ESMALTE

This study evaluated in situ the effects of bioactive agents on enamel whitened with hydrogen peroxide at 37.5%, using Knoop microhardness (KHN) and ion chromatography (IC). We selected25 third  human molars included were fragmented (3x3x3 mm). Five volunteers were selected and had five specimens attached to the buccal surface of their upper and lower molars. Each volunteer represented a group (n = 5): CONTROL: no treatment, POLA: Pola Office 37.5% (Positive Control), NANO: Pola Office 37.5% + Nanohydroxyapatite, CPP- + CPP-ACP (CPP-ACP) and NOVA: Pola Office 37,5% + NovaMin. KHN analysis (n = 5) was performed before and after treatments. Five indentations were performed, using the 25 gf load for 15 seconds. For the chemical analysis (n = 3), the samples were ground, autoclaved and subjected to acid digestion by microwave radiation. They were then diluted in 303x with distilled / deionized water. To quantify the chemical elements calcium (Ca), fluorine (F) and phosphorus (P), an ion chromatography technique was used. ANOVA followed by TUKEY (p <0.05) showed that the CPP-ACP and NOVA groups showed higher KHN means in relation to the other groups; the NANO group was statistically similar to the CONTROL group; The POLA presented the lowest KHN mean when compared to the other groups. The percentage of KHN in descending order was: CPP-ACP, NOVA, NANO CONTROLE and POLA. The use of bioactive agents in the bleaching treatment promoted an increase in the percentage of calcium, fluorine and phosphorus ions and the hardness of human enamel.