Evaluation of Marginal Adaptation of Class II Restorations Using Flowable Bulk-fil Composite and Self-Adhesive Composite

Abstract

Abstract Background: The gap caused by the polymerization shrinkage of composite restorations has an important effect in dental restorations durability, and various methods have been proposed to reduce it. Proper selection of composite and its correct use in cavities improve the marginal seal of restorations. The aim of this study was to evaluate marginal adaptation of class II restorations using flowable bulk-fil composite and self-adhesive composite as liners. Materials and Methods: This in vitro study was performed on 18 human premolars. Teeth were mounted 2 mm below CEJ in self-cured acrylic and Class II cavities were prepared in the mesial and distal surfaces. Mounted teeth divided into 2 groups randomly: In group 1, restoration using self-adhesive flowable composite (Vertise Flow) as a liner in the floor and the axial wall of the cavity and bulk fill composite(X-tra fil) in the upper part of the cavity.In group 2, restoration using flowable bulk fill composite( X-tra Base)as a liner in the floor and the axial wall of the cavity and bulk fill composite(X-tra fil) in the upper part of the cavity.Finally, polishing burs and aluminum oxide discs were used for finishing and polishing. Then they were placed in thermocycling conditions. The prepared samples were evaluated under stereomicroscope with 60x magnification and marginal gap measurement was performed by stereomicroscope software. Data were analyzed by SPSS17 software and t-test. Results: The mean marginal gap measured in the self-adhesive flowable composite group (12.10±2.91 µm) was significantly higher than the bulk fill flowable composite (7.86±1.65 µm). Conclusion: The marginal adaptation of the self-adhesive flowable composite is significantly lower than the bulk fill flowable composite.