Can antioxidant treatment replace delay in bracket bonding? An in vitro study

Abstract

Background Deterioration in shear bond strength has been reported after immediate bracket bonding following hydrogen peroxide bleaching. This study compared the effectiveness of three antioxidant agents, namely, alpha-tocopherol, green tea extract, and sodium ascorbate, in reversing the bleaching effect and as possible alternatives to delayed bonding. Methods A total of 105 extracted human premolars were arbitrarily assigned to 7 groups (n = 15 each), including group 1 as the unbleached control group and six experimental groups, which were bleached with 40% hydrogen peroxide in three sessions of 15 min each. In experimental group 2, bonding was performed immediately after bleaching, whereas in groups 3 and 4, bonding was delayed for 1 and 2 weeks, respectively; meanwhile, the specimens were immersed in artificial saliva at 37 °C. Groups 5, 6, and 7 were treated immediately after bleaching with 10% of alpha-tocopherol, green tea extract, and sodium ascorbate solutions, respectively, for 15 min. Specimens were processed using 500 thermal cycles between 5 and 55 °C, with a dwell time of 30 s after 24 h of bracket bonding, and then tested for shear bond strength. The adhesive remnant index was examined to evaluate fracture mode. One-way analysis of variance, Kruskal–Wallis H, and post hoc Tukey’s honestly significant difference tests were used to compare the data. Significant results were subjected to pairwise comparisons with Bonferroni’s correction-adjusted of p values ≤ 0.050. Results Shear bond strength was significantly lower (p < 0.001) in the immediate bonding and 1-week delay groups than in the control group. However, no significant difference was detected among the 2-week delay, antioxidant-treated, and control groups (p > 0.05). Conclusions Application of 10% alpha-tocopherol, green tea extract, or sodium ascorbate for 15 min could restore shear bond strength after 40% hydrogen peroxide bleaching as an alternative to delay in bracket bonding.

Reduction of surface treatment time by combination of citric acid and ascorbic acid while restoring shear bond strength of metal brackets bonded to bleached enamel: a pilot study

“…Numerous in vitro studies concerning applying antioxidants to enhance SBS have been performed [ 20 , 22 – 25 ]. These studies included an additional etching procedure involving phosphoric acid, leading to an increase in the duration of the clinical procedure [ 20 , 22 , 24 , 25 ].…”

“…Numerous in vitro studies concerning applying antioxidants to enhance SBS have been performed [ 20 , 22 – 25 ]. These studies included an additional etching procedure involving phosphoric acid, leading to an increase in the duration of the clinical procedure [ 20 , 22 , 24 , 25 ]. A previous study proposed a method to improve the clinical effectiveness, reduce working time, and address this concern by combining antioxidant and acid etching solutions [ 23 ].…”

Effect of antioxidant on tooth sensitivity after bleaching

“…39 Another study found that a 15-min application of antioxidants was found to be adequate after three 15-min bleaching sessions, in line with our findings. 40 The gel form was used as the key advantage of gel over solution is better control because of the gel's increased viscosity and a delayed release of the SA, which ensures its effectiveness over time. 16,37 According to the scales used for measuring tooth sensitivity, The Numerical Rating Scale (NRS) is easy to record, reliable, valid, sensitive, and presents the greatest accuracy.…”