Permeability and Microtensile Bond Strength of A New Bonding System

Objectives: Recently, a newly developed one-step self-etching adhesive system with unique activator brushes has been introduced to the market. The activator brushes are impregnated with aromatic amine and sodium sulfinate as a hydrophilic chemical-initiator. In this study, we evaluated the permeability and microtensile bond strength(MTBS) of this bonding system focusing on the characteristics of the activator brushes in comparison to other bonding systems using conventional brushes.
Methods: Three adhesive systems bonded to human dentin were evaluated: (1) Brush&Bond Universal(BBU/Parkell), (2) Scotchbond Universal(SU/3M) and (3) All Bond Universal(AU/Bisco).
Human coronal dentin discs(n=2) were pretreated with 23% phosphate for 10sec to establish tubule patency, applied an adhesive, then light-cure resin composite was placed and cured. Permeability was evaluated by SEM observation on the interface between the etched dentin and resin.
For the MTBS test, human dentin(n=2) was bonded with these adhesive systems without etching, then two kinds of dual-cure resin composite(Absolute Dentin/Parkell or HyperFIL/Parkell) were placed. After curing only by chemical mode for 30minutes, the specimens were stored in 37°C water for 24hours, then cut into 10 sticks per specimen and MTBS test was conducted to evaluate the compatibility between adhesives and dual-cure resin composite. Statistics:One-way ANOVA and Tukey’s test.
Results: The BBU SEM micrographs showed longer resin tags with lateral branches of dentinal tubules than other systems. Furthermore, no gap between the bonding resin and resin composite was observed in BBU. BBU showed the significantly higher microtensile bond strength than other systems(p<0.05)(Table.1).
Conclusions: It was concluded that Brush&Bond Universal with unique activator brushes had better permeability into dentin microstructure and had better compatibility with dual-cure resin composite.