Investigation of Shear Bond Strength of Composite Resin and Glass Ionomer Cement to Dentin with Different Roughening Methods

Objective: This study aimed to investigate the effect of different surface treatments on the bond strength of two restorative materials to dentin. Materials and Method: The occlusal enamel of 172 molars, 160 for shear bond strength testing and 12 for SEM examinations, was removed and embedded in acrylic resin blocks with the occlusal surfaces facing up. The samples randomly were divided into two groups according to material(Group C: Composite resin, Group G: Glass ionomer cement) and then into eight subgroups according to surface conditioning (Group C1, G1: No surface conditioning, Group C2, G2: Phosphoric acid, polyacrylic acid, Group C3, G3: Air abrasion, Group C4, G4: Air abrasion+acid, Group C5, G5: 1 W Laser, Group C6, G6: 1 W Laser+acid, Group C7, K7: 2 W Laser, Group C8, G8: 2 W Laser+acid). The universal adhesive was applied to the dentin sample surface for composite groups, restorative materials built up (2 mm X 3 mm), and a shear bond strength test was performed. Images of different surface treatments applied to the dentin surface were evaluated by SEM. Data were analyzed using one-way analysis of variance, post-hoc LSD tests, and independent sample t-tests(α=0.05). Results: For both materials, the acid group showed the highest shear bond strength, significantly higher than the laser and air abrasion groups(p