The in vitro evaluation of the effectiveness of polishing and surface coating after the application of three different flowable composite materials to primary molar teeth

The aim of this study was to evaluate effectiveness of polishing and surface coating on marginal adaptation and microleakage of new flowable composite restorations on primary teeth and the composites? bond strengths to primary tooth dentin by microtensile test.For the study, 120 non-caries primary molar teeth were used. Class V cavities were prepared in buccal and lingual surfaces of 60 teeth and the teeth were divided into three groups in three different flowable composites (Vertise Flow, G-aenial Universal Flo, Tetric N-Flow). Half of the restorations in each group were polished. Then the subgroups were divided into two again and surface coating (G-Coat Plus) was applied on half of the restorations. Marginal adaptation assessments were made on replicas of teeth; microleakage assessments were made on teeth.The remaining 60 teeth were abraded from buccal to expose dentin surfaces. The teeth were divided into three groups and three different flowable composites were applied dentin surfaces. Bond strengths were measured by microtensile test and fracture modes were analyzed with SEM.According to the results of this study, polishing reduced marginal adaptation and increased microleakage in all groups. When surface coating was applied that marginal adaptation and microleakage measurements were significantly successful. Bond strength values were measured respectively that 15.5MPa for G-aenial, 13MPa for Tetric, 2.3MPa for Vertise.Consequently, the surface coating applications were increased the success of restorations and self-adhering flowable composite Vertise Flow?s bond strengths were found to be inadequate. More laboratory and clinical studies are needed on newly developed materials.