Effect of thickness of flowable resins on marginal leakage in class II composite restorations.

Despite limited scientific evaluation, there is an increased use of low elastic modulus flowable resin composite (FRC) as a stress-relieving gingival increment in Class II restorations. This study compared marginal leakage in preparations with gingival margins in enamel or dentin/cementum (sub-CEJ and supra-CEJ) after FRC was used as a gingival increment to hybrid resin composite used alone. In addition, the extent of leakage around restorations with or without the use of FRC gingival increments when light curing the resin composites from occlusal direction only or buccal, lingual and occlusal directions was compared.