OBJECTIVETo compare the microleakage of compomer sealant with non-rinse conditioner and resin sealant with phosphoric acid (35%) by dye test and scanning electron microscope (SEM) observation.

METHODS16 extracted third permanent molars were divided into 4 groups: Group I, non-rinse conditioner (NRC) + Prime & Bond NT + Dyract seal; Group II, phosphoric acid (35%) + Concise sealant; Group III, phosphoric acid (35%) + Dyract seal; Group IV, NRC + Prime & Bond NT + Concise sealant. The teeth were then coated with nail polish, placed in a 50% AgNO3 dye for 18 hours, and sectioned with a diamond saw. SEM observation was performed to evaluate microleakage in the teeth.

RESULTSSilver nitrate penetration was found in each group. The percentage of microleakage in group I was higher than that in group II, and group IV was higher than that in group II (P < 0.01). The percentage of microleakage of resin sealant with phosphoric acid was lower than that in compomer sealant with NRC (P < 0.01). On SEM observation, resin tags and few gaps were found in groups with phosphoric acid. Some gaps and bubbles were found at the bottom of the fissures, particularly in the narrow fissures because of the failure of sealant penetration.

CONCLUSIONResin sealant used with phosphoric acid was better than compomer sealant with NRC on microleakage.