Class V cavities were prepared on the lingual and buccal surfaces of 50 extracted intact human posterior teeth using diamond drill. The cavities were randomly assigned to five groups: Group 1: Conditioned with laser (Energy=120mJ, Frequency=10Hz, Pulse duration=100ms for enamel and Energy=80mJ, Frequency=10Hz, Pulse duration=100ms for dentin) + Optibond FL; Group 2: Conditioned with laser + etching with 35% phosphoric acid + Optibond FL; Group 3: Conditioned with laser + Clearfil SE Bond; Group 4 (control): Acid etched with 35% phosphoric acid + Optibond FL; Group 5 (control): Only Clearfil SE Bond. All the cavities were restored using Point-4 composite resin. All samples were stored in distilled water at 37°C for 24 h, then were thermal cycled for 500 cycles and immersed in 50% silver nitrate solution for 24 h. The teeth sectioned bucco-lingually and then dye penetration was scored. Kruskal-Wallis & Mann-Whitney tests were used for statistical analyses.
Results: In occlusal margins, the least microleakage was found in groups 2, 4 and 5. The maximum microleakage was observed in group 3 (P = 0.009). In gingival margins, the least microleakage was observedd in group 2, while the most microleakage was found in group 5( P = 0.001). All the differences observed were statistically significant (P < 0.05). The microleakage scores were higher at the gingival margins.
Conclusions: The use of the Er:YAG laser for conditioning with different dentin adhesive systems influenced the marginal sealing of composite resin restorations.
Keywords: Acid etch, Composites, Conditioning, Lasers and Microleakage
See more of: Dental Materials 2: Adhesion - Leakage/Margin Assessments