Influence of curing methods and materials on the marginal seal of class V composite restorations in vitro.

The study tests the hypothesis that soft-start irradiation improves, whereas, high intensity irradiation compromises the margin quality and marginal seal of Class V resin based composite [RBC] restorations. Box-shaped Class V cavities were prepared in extracted, human third molars with cervical margins located apical to the CEJ. Cavities were restored using a multi-step bonding agent (Optibond FL, Kerr), a thin layer of flowable resin composite and two increments of fine hybrid resin composite (Filtek Flow/Filtek Z250, 3M ESPE; Revolution f2/Herculite XRV, Kerr).