Enamel bond strengths of pairs of adhesives from the same manufacturer.Oper Dent. 2005 Jul-Aug; 30(4):492-9.OD
Most manufacturers of dental adhesives have both a total-etch adhesive and a simplified self-etching adhesive available on the market. This study measured the enamel microtensile bond strengths of five pairs of enamel adhesives as a function of enamel roughness. The proximal surfaces of 25 extracted mandibular molars were sectioned with a diamond saw to obtain 50 enamel rectangles with an area of 8x4 mm2. The enamel rectangles were divided in two equal parts via a groove to obtain 4x4 mm2 squared bonding surfaces. One half was roughened with a coarse diamond bur under water for five seconds, while the other half was kept intact. The enamel surfaces were randomly assigned to 10 enamel adhesives grouped into five pairs. Each pair included one self-etch adhesive and one total-etch adhesive from the same manufacturer: Adper Prompt and Adper Single Bond (PLP and SB, 3M ESPE); AdheSE and Excite (ADH and EXC, Ivoclar Vivadent); OptiBond Solo Plus SE and OptiBond Solo Plus (OPTSE and OPT, Kerr); Tyrian SPE/One-Step Plus and One-Step (TYR and OST, BISCO, Inc); Xeno III and Prime&Bond NT (XEN and PBNT, Dentsply). The adhesives were applied according to the manufacturers' instructions. Buildups were constructed with Filtek Z250 (3M ESPE). The specimens were sectioned in sticks with a cross section of 0.8+/-0.2 mm2 and tested to failure in tension at a crosshead speed of 1 mm/minute. Two-way ANOVA followed by Duncan's post-hoc test at p<0.05 was computed. The highest mean bond strengths were obtained with total-etch adhesives. For "roughened enamel," three pairs of materials had statistically different means in which the total-etch adhesive resulted in statistically higher bond strengths (MPa) than the corresponding self-etch adhesive: EXC (36.6) > ADH (23.0) at p<0.026; OPT (34.5) > OPTSE (25.3) at p<0.028; PBNT (36.6) > XEN (19.5) at p<0.0001. For "intact enamel," four pairs of materials resulted in statistically different means: SB (31.7) > PLP (20.9) at p<0.049; EXC (37.9) > ADH (16.3) at p<0.0001; OST (30.1) > TYR (18.0); PBNT (43.8) > XEN (16.0) at p<0.0001. When the same adhesive was compared on intact vs roughened enamel, all the self-etch materials resulted in lower bond strengths on intact enamel, but this difference was only significant for TYR (p<0.042) and ADH (p<0.050). For total-etch materials, only OPT resulted in statistically lower bond strengths when applied on intact enamel p<0.011).