Marginal quality and microleakage of adhesive class V restorations

Objectives: The aim of this in vitro study was to determine the marginal quality and microleakage of composite resin class V restorations. Methods: Standardized mixed class V cavities (diameter: 4 mm, depth: 2 mm) with half of the finish lines limited within dentin were cut in 90 freshly extracted human molars and randomly assigned to nine groups (n=10). After etching enamel and dentin, the cavities were restored with nine different restorative systems (Syntac Sprint/Tetric Ceram=SS, Syntac Single-Component/Tetric Ceram=SC, Onestep/Aeliteflo=OS, Aquaprep+Onestep/Aeliteflo=OA, Prime & Bond 2.1/TPH=PB, Optibond Solo/Prodigy=OP, Singlebond/Z100=SB, Tenure Quik/Marathon=TQ, Solobond M/Arabesk=SM) using a wet-bonding procedure. After finishing and polishing, the teeth were stored for 24 h in distilled water at 37°C before they were subjected to thermocycling (5/55°C, 1000×). Epoxy replicas were made for margin analysis in the SEM. Specimens were stained in methylene blue, sectioned, and evaluated for microleakage. Dye penetration was scored on a 0–3 ordinal scale. Results: Statistical analysis (Kruskal–Wallis H-test, Mann–Whitney U-test) revealed significant differences (P<0.05) among the groups at dentin and enamel margins for the microleakage scores as well as for the results of the quantitative SEM margin analysis. SC revealed a significantly higher percentage of perfect margins in the SEM than OS and SM in enamel and dentin, respectively. OA exhibited significantly more leakage in enamel than all other groups. Conclusions: None of the tested restorative systems achieved a perfect seal in dentin and enamel of mixed class V cavities. Marginal quality and sealing ability of adhesive systems to dentin, using a wet-bonding procedure, is still inferior compared with enamel margins.