Microtensile Bond Strengths of Self-etching Adhesives with Different Application Procedures

Methods: Flattened occlusal dentin of human molars was bonded with two self-etching systems, Brush and Bond (Parkell) and Adper Prompt L-Pop (3M/ESPE). The dentin surfaces were bonded either following the manufacturers' instructions; the material and applicator were repetitively used (control group) or with a modified method; the material and applicator were renewed for each application to avoid material contamination by smear layer debris (experimental group). Composite build-up was carried out with Z100 and BisFil Core, then the specimens were stored in distilled water for 24 hours at 37°C. The specimens were cut into beams with a cross sectional area of approximately 1mm², and the beams were set onto a µ-tensile bond testing apparatus. The load was applied until a failure occurred. The bond strengths for each material were independently analyzed with a two-sample t-test (p=0.05).

Results: Results showed that the bond strengths of the specimens prepared with the modified application technique were not statistically different from that of the specimens prepared with manufacturers' instructions.

Conclusion: The smear debris did not significantly affect the bond strengths of the materials tested.

Table. Bond strengths of respective bonding procedures Mean ± S.D. Unit: MPa

The values with the same letters within the same low are not significantly different (p>0.05).