Comparative Analysis of Bond Strength Durability of 10-Methacryloyloxydecyl Dihydrogen Phosphate-Containing Adhesives on a Low-Viscosity Bulk-Fill Composite Surface.

PURPOSE:To compare the bond durability of adhesives with 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) to low-viscosity bulk-fill composite. MATERIALS AND METHODS:Four 10-MDP-containing adhesives (Tokuyama Bond Force II [TBF II], Tokuyama; Scotchbond Universal [SU], 3M Oral Care; Clearfil Universal Bond Quick [CL], Kuraray Noritake; and G-Premio Bond [GP], GC) and one 10-MDP-free adhesive (Heliobond [HB] Ivoclar Vivadent) as a control were applied to polished, air-abraded surfaces of randomly assigned SureFil SDR flow low-viscosity bulk-fill composite blocks. The application of the adhesives was followed by applying Tetric EvoCeram universal nanohybrid composite in layers. Each layered composite block was sliced into stick specimens with a hard-tissue microtome. Half of the groups were randomly selected and tested for microtensile bond strength (immediate group); the other groups were aged in a thermocyling machine for 5000 cycles, followed by testing microtensile bond strength (aged group). The adhesive interface was evaluated with scanning electron microscopy (SEM). Failure modes were observed using light microscopy. The results were evaluated with Levene's test, ANOVA, Welch's ANOVA, Tukey's test and the Z-test as appropriate (significance: p < 0.05). RESULTS:There was a significant difference in the bond strength between 10-MDP-containing adhesives and the 10-MDP-free adhesive in all groups. Aging significantly decreased the bond strength in all adhesive groups. There was no significant difference in the bond strength durability among the 10-MDP-containing adhesives. CONCLUSION:Application of 10-MDP-containing adhesives has an advantageous effect on the air-abraded SDR composite surface compared with 10-MDP-free adhesive. The composition of 10-MDP-containing adhesives did not influence the bond strength. Aging diminishes the bond strength durability of 10-MDP-containing adhesives.