Tensile bond strength of three dual-cure bonding systems.

Objectives: The purpose of this study was to test and compare the tensile bond strength of three dual-cure bonding systems on dentinal surfaces.

Methods: Scotchbond MP Plus (3M Dental Products, St. Paul, MN 55144-1000), Allbond 2 (Bisco INC. Itasca, IL 60143) and Prime & Bond 2.1 Dual Cure (DENTSPLY Caulk, Milford, DE 19963-0359) were the three agents tested following manufacturer's instructions on flat dentinal surfaces. A total of 60 teeth were obtained, prepared and stored in distilled, deionized water prior to testing. Twenty teeth were distributed randomly to each bonding agent product. Ten of the 20 were light-cured and the other 10 were activated chemically, thereby creating six experimental groups. "Enforce" (DENTSPLY Caulk) resin cement was placed in a cylinder on the bonding agent interface in all 60 teeth. A pull test was performed using an Instron machine (Instron Corp., Canton, MA 02021) at a speed of 1 mm/min and under continuous load until failure.

Results: This study demonstrated that no significant difference existed among the means of the six sample groups involved when they were compared against each other using two-way ANOVA (p < 0.05). Yet, when comparing light-cured samples as a group, versus chemically-cured samples, light-cured samples produced a significantly stronger bond. When comparing adhesive systems, regardless of the cure method, Scotchbond MP Plus resulted in a significantly stronger bond than Allbond 2. When only comparing chemically-cured samples, Scotchbond MP Plus was significantly stronger than Allbond 2. Prime & Bond 2.1 was not significantly different than Scotchbond MP Plus or Allbond 2 regardless of cure type. No difference existed when comparing only light-cured samples.

Clinical relevance: The bond strengths of adhesive systems are critical for the dentist in deciding which product to purchase to ensure the restoration will be a long-lasting one.