Effects of sealant and self-etching primer on enamel decalcification. Part I: An in-vitro study

IntroductionThe objective of this study was to compare the resistance to enamel demineralization between self-etching primer (SEP) and conventional sealant in vitro.MethodsA total of 120 molar sections were randomly assigned to 3 groups: SEP (Transbond Plus, 3M Unitek, Monrovia, Calif), sealant (Light Bond fluoride-releasing sealant, Reliance Orthodontic Products, Itasca, Ill), or control (no enamel treatment). SEP or sealant was applied following the manufacturer's recommendations. The tooth samples were exposed to rotary brushing for 2 minutes. A 2 × 2-mm window of sound enamel was created by using nail varnish. After 48 or 72 hours of acidic challenge with Ten Cate solution (pH 4.46), the samples were sectioned down to a thickness of 200 μm and stained with rhodomine B dye to evaluate lesions, lesion depths, area of lesions, and total fluorescence by using confocal microscopy. Statistical analyses were performed with 1-way analysis of variance (ANOVA) and Tukey-Kramer tests.ResultsThe incidence of lesion was 50% in the sealant group and 100% in both the SEP and the control group. The lesion in the sealant group was present only when the sealant integrity was broken. Lesion depth (149.9 ± 20.5 μm), area (636 ± 90 × 102 μm2), and total fluorescence (252 ± 83 × 104) in the SEP group were similar to those in the controls. Lesion depth (107.6 ± 45 μm), area (441 ± 212 × 102 μm2), and fluorescence (160 ± 103 × 104) in the sealant group were significantly less than in the SEP and control groups (P <0.05).ConclusionsThese results suggest that neither sealant completely protects the teeth against enamel decalcification. The application of sealant provided protection in 50% of the samples, whereas the SEP provided no resistance to enamel demineralization. Protection from acid demineralization depends on the integrity of the sealant.