Are Bonding Agents being Effective on the Shear Bond Strength of Orthodontic Brackets Bonded to the Composite

Introduction: One of the clinical problems in orthodontics is the bonding of brackets tocomposite restorations. The aim of this study was to evaluate the shear bondstrength of brackets bonded to composite restorations using Excite. Methods:Forty brackets were bonded to composite surfaces, which were embedded inacrylic resin. One of the following four protocols was employed for surfacepreparation of the composite: group 1) 37% phosphoric acid for 60 seconds, group2) roughening with a diamond bur plus 37% phosphoric acid for 60 seconds, group3) 37% phosphoric acid for 60 seconds and the applying Excite®, group4) roughening with diamond bur plus 37% phosphoric acid for 60 seconds andapplying Excite®. Maxillary central brackets were bonded onto thecomposite prepared samples with Transbond XT. Shear Bond Strength (SBS) wasmeasured by a universal testing machine. The ANOVA and Tukey test was utilizedfor data analysis. Results: There was a significant difference betweenthe four groups (P<.000). The lowest and highest SBS were attributed to theGroup 1 and Group 4 respectively. There was no significant difference betweenGroups 1 & 3, 2 & 3 and 2 & 4. However, differences between Group 1in comparison with Groups 2 and 4 and Group 3 with Group 4 were statisticallysignificant. Conclusion: According to the results of this study, theusage of Excite® alone beforebonding brackets tocomposite restorations does not cause an increase in bond strength. However,roughening the composite surface before applying Excite is very effective forimproving the bond strength of orthodontic brackets to composite restorations

Keywords:

Bond Strength , composite restorations , orthodontic brackets