Modified Microtensile Bond Strength of Glass Ionomer to Composite Resin Using Universal Adhesive in Self-etch and Total-etch Modes

Background: Glass Ionomer Cements (GICs) are frequently used as base or liner before the application of restorative materials. The success of this approach depends on the bond strength of GICs to composite resin. Objectives: This study to assess the modified microtensile bond strength of glass ionomer to composite resin using universal adhesive in self-etch and total-etch modes. Methods: Samples were fabricated of resin-modified GIC (RMGIC) and conventional GIC(CGIC) (6 x 1 x 1 mm), and were randomly divided into 8 groups. Clearfil SE Bond and G-Premio universal adhesive in self-etch and total-etch modes were used according to the manufacturers' instructions. Z250 composite was applied over the GIC (12 x 1 x 1 mm), and light-cured. The microtensile bond strength was measured using a universal testing machine. The samples in each group were evaluated under an electron microscope to determine the mode of failure. Data were analyzed using one-way ANOVA and Tukey's test. Results: The microtensile bond strength of RMGI used with Clearfil SE Bond was significantly higher than that of other groups (6.57 +/- 1.15 MPa) (P<0.05). The maximum and minimum microtensile bond strength values of CGIC after applying the bonding agents were recorded after using G-Premio total-etch mode (1.34 +/- 0.77 MPa) and SE Bond in total-etch mode(1.18 +/- 79 MPa), respectively. Conclusion: Application of of G-Premio in both modes did not show any significant different bond strength in both glass ionomers. The bond strength of RMGIC was higher than that of CGIC, and the maximum bond strength of RMGI was achieved by the use of SE Bond.