Abstract
Aim of the study: To evaluate in vitro the microleakage of fissure sealant, the effect of using home bleaching agent containing 18% carbamide peroxide and the effect of ethanol as an antioxidant agent on microleakage. Materials and Methods: Twenty four extracted sound human third molars were randomly assigned to 3 groups. After sealant placement, the teeth were thermocycled (125 cycles; 5- 55°C), isolated, immersed in 0.2% methylene blue dye for 24 hours, included in acrylic resin and sec-tioned longitudinally in a buccolingual direction. The sections were analyzed for leakage using an ste-reomicroscope, and a 4-criteria ranked scale was used to score dye penetration. Results: Microleakage scores increased with significant difference between control and bleached group when home bleach was used for fourteen days, also leakage scores decreased with significant difference when ethanol was used after bleaching to reverse the oxidation process, no significant difference was observed between control versus ethanol group. Conclusions: Microleakage scores increased after bleaching because of reduction in enamel bond strength of sealant when the bonding procedure was carried out immediately after bleaching, use of ethanol or other types of antioxidant reduced the amount of microleakage sig-nificantly.
