Purpose: To evaluate whether differences in material composition between various classes of resin-based composite and polyacid-modified resin-based composites (compomers) affect microleakage in Class V preparations.
Materials and methods: Class V cavity preparations were made in the buccal/lingual surfaces of non-carious human molars with the occlusal margins in enamel and the gingival margins in dentin. Enamel margins were beveled, preparations etched, and a single bottle dentin bonding agent was applied. Preparations were restored with the following materials (n = 20): Heliomolar RO, Tetric Ceram, Tetric Flow, Flow-It, Flow-It LF, Compoglass F, and Compoglass Flow. Restorations were polished and teeth thermocycled, stained, and sectioned to evaluate both linear and penetrating microleakage.
Results: Within all groups there was significant increase (P < 0.05) in both linear and penetrating dentin microleakage when compared to enamel microleakage. Linear gingival microleakage results indicated that Compoglass Flow and Tetric Ceram had significantly less microleakage than Flow-It and Flow-It LF and that Compoglass Flow also had significantly less microleakage than Heliomolar RO. Heliomolar RO, Flow-It and Flow-It LF had significantly more penetrating dentin microleakage than Tetric Ceram. The fact that microleakage scores between groups of materials were not significantly different indicates that the ability to predict microleakage in Class V preparations among various classes of resin-based composite or compomer materials is a much more complex phenomenon than can be simply gathered from focusing on compositional differences alone.