Objective: There is a concern about bond strength with 7th-generation bonding agents on un-cut enamel. Bond strengths of 7th-generation bonding agents (G-aenial Bond, GB; Bond Force, BF; Xeno IV, X; Optibond All-In-One, O) with composite (TPH3) on un-ground and ground human enamel and dentin with and without thermal cycling were measured. Methods: Specimens of freshly extracted human teeth were prepared as un-ground (UGE) and ground (GE) enamel and ground dentin (D) through 600-grit silicon carbide paper. GB on UGE, GE and D specimens were prepared both with and without acid etch (37% phosphoric acid). BF, X, and O were not used with phosphoric acid. Bond strengths (Ultradent shear bond test) were determined on a testing machine (Instron) at 1 mm/min after 24 h storage in water at 37°C and after thermo-cycling of 5000 cycles (TC) in water between 5 and 55°C. Results: Means and standard deviations for 24 h data are shown in the table. Data were analyzed with ANOVA at the 0.05 level of significance. Means with the same letter are statistically the same.
Bonding Agent | Substrate | Condition | Bond Strength, MPa |
GB | UGE | Un-etched | 19.9(4.8) |
GB | UGE | etched | 25.0(4.9) |
O | UGE | Un-etched | 17.9(7.0) |
X | UGE | Un-etched | 14.1(8.2) |
BF | UGE | Un-etched | 9.6(3.3) |
GB | GE | Un-etched | 29.3(2.8)a |
GB | GE | etched | 27.9(4.0)a |
O | GE | Un-etched | 25.7(2.9)b |
X | GE | Un-etched | 20.6(2.8) |
BF | GE | Un-etched | 24.7(1.0)b |
GB | D | Un-etched | 31.4(3.6)c |
GB | D | etched | 29.2(6.1) |
O | D | Un-etched | 32.9(5.1)c |
X | D | Un-etched | 26.4(5.1) |
BF | D | Un-etched | 17.8(1.6) |
Conclusions: Bond strength of GB to etched UGE after 24 h was statistically higher than O, X and BF. Bond strength of GB to etched UGE is statistically higher than to un-etched UGE after 24 h. Bond strengths of GB on un-etched UGE, GE and D were statistically higher than those of X and BF for 24 h and TC. Supported by GC America.