Comparison of the effect of three mechanical surface treatments on the repair bond strength of a laboratory composite.
OBJECTIVE
This study compared the effects of three mechanical surface treatments, including diamond bur, air-abrasion, and Er, Cr: YSGG laser on the repair bond strength of a laboratory composite resin.


BACKGROUND
A proper bonding must be created between the existing composite and the new one for successful repair.


METHODS
Sixty cylindrical specimens of a laboratory composite resin (Gradia) were prepared and randomly divided into four groups (n = 15). Groups 2-4 were treated with diamond bur, air-abrasion, and Er, Cr: YSGG laser, respectively; group 1 was the control group, without any mechanical surface treatment. The topographical effects of different mechanical surface treatments were characterized by atomic force microscope. Silane and a bonding agent (Single Bond) were used in all of the groups before adding a direct resin composite. Then, the specimens were subjected to a shear bond strength test. Failure modes were evaluated under a stereomicroscope. All data were analyzed by one-way ANOVA and Tukey test at a significance level of p < 0.05.


RESULTS
There were statistically significant differences in bond strengths between the groups (p < 0.0005). Differences in bond strengths between group 1 and the other groups were significant (p < 0.0005). Furthermore, there were significant differences in bond strengths between group 2 and groups 3 and 4 (p < 0.0005), while the bond strength differences between groups 3 and 4 were not significant.


CONCLUSIONS
Based on the results of this study, Er, Cr: YSGG laser was confirmed to be as effective as air-abrasion for laboratory composite repair.
Department of Operative Dentistry, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran. kimyais@tbzmed.ac.ir
Soodabeh
S
Kimyai
Narmin
N
Mohammadi
Elmira Jafari
EJ
Navimipour
Sahand
S
Rikhtegaran
D020906:Air Abrasion, Dental; D017438:Bisphenol A-Glycidyl Methacrylate / Q000627:therapeutic use; D003188:Composite Resins / Q000627:therapeutic use*; D001840:Dental Bonding; D003793:Dental Restoration, Permanent / Q000379:methods; D006801:Humans; D013718:Tensile Strength; D019246:Tooth Preparation / Q000379:methods*
D003188:Composite Resins; C470230:Gradia; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate