The Bond and Rebond Strength of Two Orthodontic Adhesives on Enamel Surfaces
Format of Original
Journal of Dental Research
Objective: This study was to determine the effects of multiple pumice prophies, acid etchings, and enamel reconditioning on the shear bond strength and shear rebond strength of orthodontic brackets using two different adhesives.
Purpose: To determine if there was a difference in the shear bond and shear rebond strengths between a traditional composite resin adhesive and a poly-acid modified composite adhesive.
Methods: Brackets were bonded, with one of the two adhesives, to extracted human premolars and then debonded with a shear force in the Instron Universal Testing Machine. The enamel surface was then reconditioned with a 12-fluted tungsten finishing bur in a high speed handpiece to remove the bulk of the adhesive and then the same bur in a slow speed for finishing. This was followed by a coarse pumice prophy and the rebonding of a new bracket. The same bedonding procedure was then conducted. Both adhesive groups were then reconditioned, rebonded, and the debonded again following the same procedures as the previous steps. Data was collected for three debondings of each specimen in both adhesive groups and analysed using a one-way ANOVA and Tukey HSD system.
Results: 1) No statistically significant difference between shear bond strength values obtained for specimens within the Transbond XT group, or within the Ultra Band-Loc group over the three debonds (p<0.05); 2) highly significant difference (p<0.001) between initial shear bond strength of Transbond XT and a second bonding shear bond strength of Ultra Band-Loc.
Conclusion: Both Transbond XT and Ultra Band-Loc are capable of producing shear bond and shear rebond strengths that are similar and capable of withstanding applied forces of mastication.