Objective: The purpose of this study was to compare the shear bond strength of various self-etch bonding agents. Methods: The buccal and lingual enamel (E) and dentin (D) of recently extracted human molars was flattened and prepared with 600 grit sandpaper, and teeth randomly divided into 24 groups (n=10), consisting of 6 adhesives: Prompt L-Pop (3M-ESPE); Clearfil SE (Kuraray); Clearfil Linerbond 2V (Kuraray); Optibond Solo Plus Self Etch (Kerr); Optibond Solo Plus Self Etch plus dual cure activator (Kerr); Optibond Solo Plus total etch (Kerr); 2 substrates: E and D; and 2 times: 5 minutes (I) and after 24 hour storage in 37oC water (L). Bonding agents were applied according to manufacturer instructions. Composite (Herculite A2, Kerr) was applied in two-2mm increments using a single plane shear testing device (Watanabe jig), cured for 40 sec each, and tested in shear on a universal testing machine (crosshead=5.0mm/min). Data was analyzed with three-way ANOVA/Tukey’s (p £ 0.05). Results:
| Group | E/I | E/L | D/I | D/L | Significant interactions were present for adhesives x substrate and adhesives x time. There were no differences for dentin vs enamel bond strength, except for Opti SE at 24 hrs. |
| Prompt | 14.1 (2.6)b,c | 22.4 (7.9)b | 14.3 (3.4)a,b | 18.0 (7.3)c,d | ||
| Clearfil SE | 22.1 (3.3)a | 28.6 (4.8)a,b | 21.2 (2.8)a | 24.8 (3.4)b,c | |
| Clearfil 2V | 16.5 (2.5)a,b | 25.5 (4.1)a,b | 18.9 (2.9)a,b | 25.9 (4.9)a,b | ||
| Opti SE | 16.0 (2.1)a,b,c | 23.7 (4.4)a,b | 19.6 (2.9)a | 33.0 (5.8)a | |
| Opti SE DC | 9.3 (2.3)c | 11.1 (3.1)c | 11.9 (3.1)b | 13.2 (4.3)d | ||
| Opti TE | 20.7 (3.7)a,b | 30.3 (3.1)a | 17.8 (4.1)a,b | 25.8 (6.9)b | |
Column groups connected by the same superscript are statistically similar. Conclusions: Clearfil SE, Clearfil 2V, Opti SE were comparable to total etch for both substrates and times. This study was supported by Kerr, Inc.