Bond strengths of a new dentin adhesive system

Purpose: This in vitro study evaluated the shear dentin bond strengths of EBS, a new three-component adhesive system containing an aqueous primer. Two other adhesive systems (Scotchbond Multi-purpose and OptiBond FL) were included in the study for comparison. A simple tensile test and the effect of composite restorative material on shear bond strength were also evaluated. Materials and Methods: Eighty bovine teeth were obtained, embedded in acrylic, polished to 600 grit to form standardized dentin specimens, and randomly assigned to eight treatment groups. Resin composite was placed in gelatin capsules and bonded to dentin using the three adhesive systems. Each system was used according to manufacturers' instructions on dentin that was blotted to remain moist after etching. Each bonding system was used with its own manufacturer's composite material, and EBS and OptiBond FL were also used with a higher modulus composite, Z100. Specimens were stored in water for 24 hours, and bond strengths were determined using an Instron universal testing machine. Results: EBS/pertac II had a mean shear bond strength of 17.2 MPa, which was significantly less than Scotchbond Multi-Purpose/Z100 (22.5 MPa) but similar to OptiBond FL/Herculite (16.4 MPa). Shear bond strengths of EBS and OptiBond were only slightly higher when they were used with Z100 composite. Tensile bond strengths were less than shear bond strengths but were nearly identical for all three systems (range: 8.0-9.8 MPa).