Effect of wet and dry bonding techniques on marginal leakage

To evaluate the effect of wet and dry bonding on microleakage of Class V restorations bonded with three bonding agents.

60 extracted human premolars and molars were randomly assigned to three groups for bonding with Gluma CPS, EBS (ESPE) and Prime & Bond 2.1. Cavities were cut in both the buccal and lingual surfaces. Half of each preparation was in enamel and the other was in cementum/dentin. The cavities were restored with composite after the application of dentin bonding agents using a wet and dry technique for each material. The teeth were stored in distilled water for 6 days at 37 degrees C, thermocycled, and the restorations examined microscopically for leakage using Procion Brilliant Red as a marker.

All groups showed microleakage at both the enamel and dentin margins. At the gingival margin, there was a significant difference between the groups for both wet-bonding (P = 0.039) and dry-bonding (P = 0.024). There was no significant difference between the groups at the enamel margin (wet bonding: P = 0.179, dry-bonding: P = 0.357). The wet-bonding technique was compared with the dry-bonding technique for each material at both the gingival and enamel margins and no significant differences were observed (in all cases P > 0.47). SEM showed that in dye-labeled areas debonding occurred mostly, but not always, near the resin-hybrid interface.