Dentin Bond Strength of Bulk Fill Resin Composites

Objectives: The objective of this study is to evaluate the dentin shear bond strength of a contemporary bulk fill resin composite in conjunction with universal bonding agents using self-etch bonding technique.
Methods: Human molars were sectioned, mounted and ground to a flat dentin surface using 320/400/600 grit SiC polishing paper. Specimens (n=10) were randomly distributed into five experimental groups. Three universal bonding agents [Adhese^® Universal/Ivoclar Vivadent ((AU)/Groups: 1-3); Scotchbond^TM Universal/3M ESPE ((SBU)/Group-4); OptiBond^TM eXTRa Universal/Kerr^TM ((OB)/Group-5)] were tested. A self-etch bonding technique was used for all test groups. Adhesives were applied to dentin surface and light cured following manufacturer’s recommended technique and timeframe. Excess adhesive was dispersed with air to produce an immobile layer prior to light curing (Bluephase^® G4/Power intensity: 1200±50 mW/cm²).
Five resin composites [(Tetric^® EvoCeram (A2)/TE/Group-1; Tetric^® EvoCeram Bulk Fill (IVA)/TEB/Group-2; Experimental Bulk Fill Composite (IVA)/EB/Group-3)-Ivoclar Vivadent; Filtek^TM One Bulk Fill (A2)/3M ESPE/F1B/Group-4; SonicFill^TM 3 (A2)/Kerr^TM/SF3/Group-5] were tested. The shear bond specimens were fabricated with an Ultradent jig by condensing resin composite through the plastic mold insert (Diameter-2.38mm) and light cured per manufacturer's instructions. Specimens were stored in the incubator (37°C/100% humidity) for 24 hours. Each specimen was tested in the Instron Universal Testing Machine with a crosshead speed of 1.0 mm/min. Data was analyzed by one-way Analysis of Variance (ANOVA) and Tukey’s HSD post-hoc test (α=0.05).
Results: The following shear bond strengths (Mean±SD) were obtained. Groups showing different superscripts were significantly different (Table 1).
Conclusions: Within the limitation of the study, no significant difference in shear bond strength was observed between test groups including new experimental bulk fill resin composite.