Effects of self-etching primer on shear bond strength of orthodontic brackets at different debond times.
OBJECTIVE
To evaluate the effect of a self-etching primer on shear bond strengths (SBS) at the different debond times of 5, 15, 30, and 60 minutes and 24 hours.


METHODS
Brackets were bonded to human premolars with different etching protocols. In the control group (conventional method [CM]) teeth were etched with 37% phosphoric acid. In the study group, a self-etching primer (SEP; Transbond Plus Self Etching Primer; 3M Unitek, Monrovia, Calif) was applied as recommended by the manufacturer. Brackets were bonded with light-cure adhesive paste (Transbond XT; 3M Unitek) and light-cured for 20 seconds in both groups. The shear bond test was performed at the different debond times of 5, 15, 30 and 60 minutes and 24 hours.


RESULTS
Lowest SBS was attained with a debond time of 5 minutes for the CM group (9.51 MPa) and the SEP group (8.97 MPa). Highest SBS was obtained with a debond time of 24 hours for the CM group (16.82 MPa) and the SEP group (19.11 MPa). Statistically significant differences between the two groups were not observed for debond times of 5, 15, 30, or 60 minutes. However, the SBS values obtained at 24 hours were significantly different (P < .001).


CONCLUSIONS
Adequate SBS was obtained with self-etching primer during the first 60 minutes (5, 15, 30 and 60 minutes) when compared with the conventional method. It is reliable to load the bracket 5 minutes after bonding using self-etching primer (Transbond Plus) with the light-cure adhesive (Transbond XT).
Turk
Tamer
T
University of Ondokuz Mayis, Faculty of Dentistry, Department of Orthodontics, Samsun, Turkey. turkset@superonline.com
Elekdag-Turk
Selma
S
Isci
Devrim
D
D000704:Analysis of Variance; D001641:Bicuspid; D002484:Cementation; D016009:Chi-Square Distribution; D017005:Dental Debonding; D045662:Dental Etching / Q000379:methods*; D003799:Dental Stress Analysis; D006801:Humans; D008422:Materials Testing; D016910:Orthodontic Brackets; D010756:Phosphoric Acids; D019279:Resin Cements; D013193:Stainless Steel; D013997:Time Factors
D010756:Phosphoric Acids; D019279:Resin Cements; C429625:Transbond Plus Self-Etching Primer; C477790:Transbond XT; D013193:Stainless Steel; C030242:phosphoric acid