Microleakage of composite restorations with Syntac Bond and Denthesive

The purpose of this study was to assess, in vitro, the microleakage of Class V restorations using two new dentin bonding agents with light polymerized resin composite. Restorations were placed in cavities prepared in extracted human premolars using either a bulk or incremental packing technique. Dentin bonding agents were applied according to the manufacturer's instructions. The enamel margin of each tooth was etched with 37% orthophosphoric acid. The teeth were stored for 6 weeks at 37 degrees C, thermocycled, and the restorations examined for leakage using methylene blue dye. The teeth were sectioned buccolingually through the restorations and the degree of microleakage assessed visually. All groups of teeth showed some degree of leakage at the gingival margin. There was a significant difference between the cavities restored by bulk packing of the resin composite and those where the resin had been applied incrementally for both materials (P < 0.05). There was no significant difference in leakage between the two dentin bonding agents (P > 0.05).