Dentin Bond Strength of 5th Generation Adhesives

Total-etch one-bottle adhesives (5^th generation) simplify the restorative procedure by combining priming and bonding into one step.  Objective: To measure and compare the dentin bond strength of several commercial 5^th generation dental adhesives: OptiBond Solo Plus (Kerr), Single Bond Plus (3M ESPE), One-Step Plus (Bisco), Prime&Bond NT (Dentsply), and XP Bond (Dentsply).  Method:  Dentin surface was first flattened with 600 grit SiC paper and then etched with phosphoric gel etchant.  Each adhesive was applied according to manufacturer's instructions for use and light-cured.  A bonding jig (Ultradent Products, Inc) with a cylindrical mold (D=2.38mm) was securely placed on the adhesive-covered dentin surface and Herculite XRV composite resin (A2 shade, Kerr) was condensed into the mold and light-cured.   The bonded specimens (n=6 for each cement) were then stored in de-ionized water at 37ºC for 24 hours before being subjected to shear force on an Instron mechanical tester.  Results:  ANOVA analysis revealed that the dentin bond strength of OptiBond Solo Plus is significantly (p < 0.05) higher than those of other adhesives which are not statistically different (p > 0.05) from each other.  

Adhesive Systems	Dentin Shear Bond Strength (MPa)
OptiBond Solo Plus	31.3±2.7a*
One-Step Plus	22.9±6.5b
Prime&Bond NT	22.6±1.9b
Single Bond Plus	21.9±3.6b
XP Bond	21.3±1.7b

*Means with different letters are statistically different at p < 0.05.

Conclusion:  OptiBond Solo Plus had the highest dentin bond strength among all 5^th generation dental adhesives tested in this study.