In vitro evaluation of effects of two different seal materials on enamel demineralization

The aim of this in vitro study was to evaluate the effects of two different seal materials on enamel demineralization which can occur during orthodontic treatment. In this study, 60 caries-free human premolars are allocated to three groups and brackets were placed on the teeth with TransbondTM XT paste. As a bonding material, in one of the groups TransbondTM XT primer is used, in the other group ProSealTM and in the last group BisCoverTM LV is used. All samples were then cycled for 30 days through a daily procedure of demineralization for seven hours and remineralization for 16 hours at 37°C to simulate the body temperature. Teeth were examined by laser fluorescence device, DIAGNOdent at the beginning and the end of the pH cycling procedure. In addition, at the end of the pH cycling procedure the teeth were sectioned and evaluated quantitatively by cross-sectional microhardness testing. Each sample was assessed by microhardness profiles across the cut surface with a microhardness tester (Micromet 5114, Buehler®) fitted with a Vickers diamond. On each sample indentations were made on 7 positions and 5 depths. According to the data obtained, when used in combination with the beginning and the end of DIAGNOdent readings, significant differences are observed. The analysis of the end of DIAGNOdent readings showed significant differences that the fluorescence degrees of ProSealTM group were lower than the other two groups, the fluorescence degrees of BisCoverTM LV were lower than the TransbondTM XT group. According to the cross-sectional microhardness test results, it is found that hardness numbers of ProSealTM group were higher than the other two groups and hardness numbers of BisCoverTM LV group were higher than the TransbondTM XT group. In the statistical analyses of the hardness numbers between depths, no significant results are obtained in the ProSealTM group. Beyond this, in both goups, BisCoverTM LV and TransbondTM XT, a significant demineralization is observed through 90 ?m from the outer enamel surface. The sealants, ProSealTM and BisCoverTM LV, result in a significant reduction of enamel demineralization in vitro. Bonding material TransbondTM XT, showed no significant results in reduction of enamel demineralization in vitro.