Bond Strengths of Two Adhesives and Effects of Application Method.
Objective: To evaluate dentin bond strength of a current self-etching primer and a new one-step bonding system and effects of different application methods in Vitro. Materials and Methods: Dentin disks were prepared from occlusal dentin of extracted human premolars and polished with 600-grit SiC papers and randomly distributed into six groups (N=10). Three groups were treated with Clearfil SE bond (Kuraray):1-According to the manufactures instructions, 2-The primer briefly air blown and 3-Primer applied for 60 seconds and the other three with SSB-200(Kuraray): 4-According to the manufactures instructions, 5- Adhesive air dried for a longer period and 6-Adhesive applied for 60 seconds. The specimens were subjected to the micro-shear bonding test after composite (APX, Kuraray) placement and 24 hours storage in saline at 37c. Data were analyzed using one way ANOVA and Fisher's PLSD at the significance level of 0.05. Results: When following manufacturer suggested application method SE bond showed higher bond strength than SSB-200(p<0.05)
|
SE BOND |
Mean(SD) in MPa |
SSB-200 |
Mean(SD) in MPa |
|
1 |
50.6(12.0) |
4 |
40.4(7.70) |
|
2 |
39.3(10.4) |
5 |
36.2(8.38) |
|
3 |
46.3(12.0) |
6 |
36.9(5.32) |
Group2 (incomplete air dry) showed significantly lower bond strength than the other two SE Bond groups. Extension of application period of the self-etching primer (Group3) or All-in-one adhesive (Group6) did not significantly affect the bond strength; neither did the extension of air drying time of in group5. (p>0.05) Conclusion: The new all-in-one adhesive showed lower bond strength to dentin than the two-step self etching primer adhesive; however, regarding the results and standard deviation values, this new adhesive seems to be less technique sensitive. Twenty seconds application of the self-etching agents could sufficiently etch dentin surface so extension of etching time is not necessary. Supported by the COE Program, at TMDU.