The purpose of this study was to evaluate the effect of dentin adhesive system on sealant bond strength under saliva contaminated condition. Moisture contamination of enamel during application of sealant is the most frequently cited reason for sealant failure. Bond strength of sealant to enamel was measured in vitro, with dentin adhesive system(primer and adhesive) under various conditions of contamination. One hundred twelve human molars were divided randomly into fourteen groups. Two kinds of sealants were used: Concise(3M, U.S.A.) and Teethmate-F (Kuraray, Japan). The enamel samples, etched for 30 seconds with 37% phosphoric acid´ gel, were contaminated with none, water or fresh whole saliva. All contaminated conditions were tested for sealant bond strength with primer alone or primer & adhesive both as an intermediate layer under the sealant. As the control groups, sealants were applied to clean dried enamel. Bond strength was measured using the Universal Testing Machine(Zwick Co., Germany). Dentin adhesive system under sealant on saliva contamination yield bond strengths equivalent to the bond strength obtained when sealant was bonded directly to clean dried enamel. There was no significant difference between using primer alone and primer & adhesive both.
The results obtaind were as follows ;
1. There was no significant difference in bond .:.rength between the control group and the group using dentin adhesive system under wet condition. Therefore, application of dentin adhesive system is recommended when fissure sealing is done under the environment susceptible to saliva contamination.
2. The shear bond strength of Concise is significantly higher than that of Teethmate-F(P<0.05).
3. Except in the no contamination group, use of primer only and use of primer & adhesive under sealant showed no significant difference in bond strength.
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