The European Journal of Orthodontics Advance Access originally published online on February 22, 2006
The European Journal of Orthodontics 2006 28(4):400-404; doi:10.1093/ejo/cji107
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bonding characteristics of a self-etching primer and precoated brackets: an in vitro study
* Department of Orthodontics, Dental Institute of King's College London, UK
** Department of Biomaterials Sciences, Dental Institute of King's College London, UK
Address for correspondence, Sunil Hirani, Department of Orthodontics, Floor 22, Guy's Tower, Guy's Hospital, London Bridge SE1 9RT, UK, E-mail: sunilhirani{at}aol.com
Little is known about the performance of TransbondTM Plus Self-Etching Primer (TPSEP), especially when used with Adhesive Precoated BracketsTM (APC 1 and APC 2). The aim of this study was to compare the shear bond and rebond strengths and failure sites of APC 1 and APC 2 with a non-coated bracket system [Victory Series (V)] using Transbond XTTM light-cured adhesive and TPSEP or 37 per cent phosphoric acid as the conditioner.
The results demonstrated that on dry testing of 120 brackets when applying an occluso-gingival load to produce a shear force at the brackettooth interface, there was no statistically significant difference in the shear bond strength (SBS) of APC 1 (68.4 N), APC 2 (74.9 N), and V brackets (75.4 N, control group). There was also no significant difference in bond failure sites of the APC 1 and APC 2 when compared with the non-coated bracket system using Transbond XT light-cured adhesive and TPSEP, with bond failure for all groups occurring mainly at the adhesiveenamel interface. There was a significant difference in the SBS of the V brackets when using TPSEP and 37 per cent phosphoric acid as the conditioners. The latter was lower (60.6 N) and the bond failure site changed from the enameladhesive interface to the bracketadhesive interface.
The shear rebond strengths of all bracket types were statistically significantly lower (P < 0.05) than their initial SBS (APC 1, APC 2, and V: 35.9, 36.7, and 34.1 N, respectively) and the locus of bond failure altered from the adhesiveenamel interface to the bracketadhesive interface. A clinical trial using TPSEP as a conditioner would be useful as the time taken to remove the adhesive from the enamel surface may be reduced following debond.