The shear bond measurement of two self-adhesive composite resins to both enamel and dentin (An in vitro study)

Abstract

Background and objectives: The aim of this study is to measure the shear bond strength of two self-adhesive composite resins (Vertise Flow, Kerr and Constic, DMG) to both enamel and dentin and compared it to that of conventional flowable composite (used with self-etching bonding system).Methods: Sixty freshly extracted human third molar teeth were chosen for this study (thirty for enamel samples and thirty for dentin samples). The teeth were mounted horizontally, in blocks of self-cured acrylic resin to leave only buccal surfaces exposed. Then 0.5 and 2mm were cut from the buccal surface to obtain flat enamel and dentin surfaces successively. Thirty enamel samples were divided into three groups; group E1: Vertise Flow, group E2: Constic and group E3: conventional composite with self-etching bonding. Also the thirty dentin groups were divided into three groups, group D1, D2 and D3 with the same corresponding composites as in enamel groups. For all the specimens composite cylinders (4mm height and 4 mm in diameter) were built of the flat surface of the sample then subjected to shear bond testing in a universal testing machine. Results: Group E3 (conventional flowable composite bonded to enamel) had the highest bond strength while group D1 ( Vertise Flow bonded to dentin) had the lowest bond.Conclusion: Both self-adhesive composites provided insufficient shear bond strength less than that required for using in most clinical conditions.Keywords: Shear bond strength, self-adhesive, Vertise Flow, Constic.