LABORATORY EVALUATION OF ONE-COMPONENT ENAMEL DENTIN BONDING AGENTS/

Purpose: To evaluate the bonding efficacy of five commercial and one e xperimental one-component enamel/dentin adhesives. Materials and Metho ds: The adhesives One-Step (BOS), Primabond (PAB), Prime & Bond 2.0 (P B2), Solist (SOL), Tenure Quik (TEQ), and an experimental compound (EX P) were investigated. The adhesives were used to bond a hybrid-type re sin composite to enamel and dentin. Shear bond strength (SBS) to human teeth was determined after 24-hour storage in water. The marginal per formance was evaluated on restorations in 3.5 mm wide cylindrical dent in cavities as the maximum gap width found 15 minutes after light acti vation. The hybrid layer thicknesses at the cavity margin were measure d by light microscopy. Results: Mean SBSs to enamel were between 23 an d 35 MPa, those to dentin between 3.5 and 25 MPa. BOS and EXP showed t he highest bond strengths to dentin and consistently gap-free restorat ions. PB2 mediated significantly lower SBS to dentin; only three of th e six restorations were gap-free. SOL exhibited poor marginal quality (mean MGW 7.5 mu m) despite 15 MPa dentin bond strength. PAB and TEQ d emonstrated very low SBS to dentin. None of the restorations with thes e products was gap-free. All adhesives produced hybrid layers between 2 and 10 mu m thick, as a coupling zone between dentin and restoration . Adhesives with the essential components of wetting monomer, well-pol ymerizing dimethacrylate, and acetone as the water-chasing solvent, pe rformed very well when used with a moist bonding technique.