Microtensile Bond Strength of Various Current Adhesive Systems to Dentin

Objectives: Using the microtensile bond test (µTBS), this study investigated the bond strengths of four two-step self-etching adhesives, seven all-in-one adhesives and four two-step total-etch systems and compared the data to those of a three-step total etch adhesive.

Methods: Sixty-four extracted human molar teeth were ground to 600-grit to obtain flat dentin surfaces. Adhese (A-SE/Ivoclar-Vivadent), Protect Bond (PB/Kuraray) Silorane System Adhesive (SSA/3M ESPE), SE Adhesive (SEA/3M ESPE), Optibond All in One (OP/Kerr), S³ Bond (SB/Kuraray), Xeno V (XE/Dentsply DeTrey), Futurabond NR (F-NR/Voco), GO (GO/SDI), G Bond (GB/GC), Adhese One (A-SEO/Ivoclar-Vivadent) Tetric N Bond (TNB/Ivoclar-Vivadent), XP Bond (XPB/Dentsply DeTrey), Peak LC Bond (P-LC/Ultradent), Single Bond 2 (SB2/3M ESPE) and Scotchbond Multi Purpose (SBMP/3M ESPE) were used as adhesive systems. Adhesives were applied on dentin surfaces according to the manufacturers' instructions. Than a resin composite was applied on adhesive-treated dentin surfaces in two increments of 2mm and polymerized. Rectangular sticks (0.9-1mm²) were obtained and subjected to µTBS testing (Bisco Microtensile Tester) after 48 hours of water storage at 37°C.

Results: The data were statistically analyzed using one-way ANOVA, Dunnett C and Tukey's post-hoc tests with significance defined as p<0.05. The µTBS test results of the adhesive systems in MPa and their respective SD values are: SBMP: 20,04±3,88^c; TNB: 38,96±4,51^a; XPB: 27,02±6,79^b; SB2: 18,75±6,39^c,f; PLC: 18,08±5,25^c,g; SEA: 37,47±13,02^a; SSA: 21,48±8,48^b,c,e; A-SE: 19,95±4,02^c; PB: 19,15±5,62^c,d; OP: 21,66±5,60^b,c; SB: 18,41±2,85^c,h; XE:14,81±5,19^{d,e,f,g,h,j,l}; F-NR: 12,89±3,84^j,k,l; GO: 9,78±3,00^i,k; GB: 8,58±3,02ⁱ and A-SEO: 6,62±3,37ⁱ. The same superscript letters indicate no statistically significant differences between the systems tested.

Conclusions: The progress in the adhesive technology has led to high-quality fewer-step adhesives revealing sometimes higher bond strengths to dentin than "golden standard" three-step adhesives. However, some all-in-one adhesives still need to be improved for better bond strength values.

The adhesives tested in this study were generously donated by their respective companies.