Microleakage of resin-based composite restorations using different solvent-based bonding agents and methods of drying acid-etched dentin

To evaluate the effect of a wet, conventionally dried, and dry bonding technique on microleakage of Class V resin-based composite (RBC) restorations bonded with three different solvent-based adhesive agents.

Forty five extracted human premolars and molars were randomly assigned to nine groups for bonding with Syntac original, Syntac Single Component, or Syntac Sprint (all by Ivoclar/Vivadent). 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 RBC after the applications of dentin bonding agents to acid-conditioned cavities using a wet, conventionally dried, and a dry technique for each material. The teeth were thermocycled and the restorations examined microscopically for leakage using Procion Brilliant Red as a marker. SEM microphotographs were prepared from dye-labeled and non dye-labeled areas.

All groups showed microleakage at the gingival margins with no significant difference between the groups irrespective of the bonding material or the method of drying acid-etched dentin [Kruskal-Wallis: (ANOVA) P = 0.1858]. Neither was there a significant difference between the groups irrespective of bonding material or drying method at the enamel margin [Kruskal-Wallis: (ANOVA) P = 0.3434). SEM showed that in dye-labeled areas debonding was predominantly cohesive in resin.