Methods: 150 maxillary premolars were divided into 3 groups after etching: dry, wet with water, and contaminated with saliva. Each of them was divided to 3 subgroups: use of ethanol base bonding (Single Bond), use of acetone base bonding (Solobond), and without bonding (N=15). Eventually, the fissures were covered with Clinpro sealant. After thermocycling, the amount of microleakage was assessed using dye penetration technique qualitatively. Data were analyzed using Kruskal-Wallis and Mann-Whitney tests.
Results: The use of Solobond significantly decreased microleakage compared to Single Bond (P<0.001) and without bonding (P=0.001). Regarding surface conditions, the microleakage of wet and dry enamel were significantly lower than contaminated enamel (P<0.001), but there was no significant difference between dry and wet enamel (P=0.11). The highest microleakage was found in saliva contaminated-without bonding sealants and the lowest microleakage in dry-without bonding and dry-Solobond groups.
Conclusions: Acetone base bonding compared to ethanol base bonding showed considerable superiority in reducing microleakage under salivary contamination. But the best method was applying sealant directly on the dry enamel without intermediate bonding layer.