Influence of marginal bevels on microleakage around Class V cavities bonded with seven self-etching agents

To evaluate microleakage around Class V resin-based composite restorations in box-shaped cavities with and without marginal bevels, bonded with one of seven self-etching materials and a non-self etching system.

120 extracted human premolars were randomly assigned to eight groups for bonding with the following self-etching agents: Prompt-L Pop, Adper Prompt, Clearfil SE, Prime& Bond NT with NRC, Xeno111, One-Up Bond, AdheSe, or Prime & Bond NT using a total etch technique (36% H2PO4). Box cavities were cut in both the lingual and buocal surfaces. The cavities were made with an ISO 010-fissure diamond bur in a water-cooled high-speed handpiece and were approximately 3 mm wide, 1.5 mm deep, and 2.0 mm high. Selected at random, box-shaped cavities were cut with a 0.5 mm bevel in enamel and dentin on one side and on the contra-lateral side, box-shaped cavities were cut without bevels. Each tooth served as its own control. The teeth were thermocycled and the specimens prepared and examined for microleakage using Procion Red as a marker.

All gingival margins leaked whether or not a bevel had been placed, when bonded either with a self-etching agent or using a total etch technique with 36% phosphoric acid. There was no significant difference in leakage between the self-etching groups or those using a total etch technique, at the gingival bevel margins, (P= 0.7384) or the gingival non-beveled margins (P= 0.2307; Kruskal-Wallis Test). Microleakage was found with every agent, both occlusally and gingivally, when bonded either with a self-etching agent or using a total-etch technique. There was no significant difference in leakage between the self-etching groups or those using a total etch technique at the enamel bevel margins, (P= 0.9907) or the enamel non-beveled margins (P= 0.9963; Kruskal-Wallis Test).