Reversal of Compromised Bonding in Bleached Enamel Using Antioxidant Gel

Abstract

Dental bond strength is significantly reduced when bonding is performed immediately after bleaching treatments. It has also been reported that the application of an antioxidant after bleaching treatment improves the adhesive bond strength of oxidized enamel tissue. The application of an antioxidant in gel form by the patient makes the application process easier and shortens time spent in the clinic. SUMMARYMany studies have shown a considerable reduction in the enamel bond strength of resin composite restorations when the bonding procedure is carried out immediately after bleaching. These studies claim that a certain waiting period is needed prior to performing the restoration in order to attain the original bond strength values. This study determined the most effective time duration for the application of sodium ascorbate prepared in gel form. The labial surfaces of 70 bovine incisors were polished with 600-grit silicon carbide paper on a water-irrigated metallurgical polishing wheel. The specimens were randomly divided into seven groups: 1) bleaching (10% Rembrandt Xtra-Comfort +) immersed in artificial saliva for seven days, 2) bonded immediately after bleaching, 3) bleaching + 10% sodium ascorbate (SA) gel for 10 minutes, 4) bleaching + 10% SA gel for 60 minutes, 5) bleaching + 10% SA gel for 120 minutes, 6) bleaching + 10% SA gel for 240 minutes and 7) bleaching + 10% SA gel for 480 minutes. After preparation, a standardshaped resin composite was applied to all specimens. The teeth were stored in distilled water at 37˚C for 24 hours and a universal testing machine determined their shear bond strength. The data were evaluated using ANOVA and Tukey tests. Antioxidant gel proved to be effective for increasing the shear bond strength of the resin composite to enamel. For maximum effectiveness, antioxidant gel should be applied to enamel for

Effect of Three Different Antioxidants on Shear Bond Strength of Composites To Bleached Enamel - An In Vitro Study

“…Management of these discolorations can be done conventionally, by using a veneer/crown or more conservatively by bleaching. [1][2][3] Various concentrations of peroxide are being used as whitening systems to bleach enamel. Hydrogen peroxide because of its low molecular weight diffuses through enamel, decomposes into oxygen and perhydroxyl free radicals.…”

Comparison of efficacy and outcome satisfaction between in-office and home teeth bleaching in Chinese patients

“…Bleaching studies that compared different Asian ethnic groups (e.g., Chinese, Koreans, Japanese, and Malays) will be more relevant as dissimilarities arising from genetic alternations and environmental influences are anticipated. A two-fold increase in ΔE* (3.23-6.35) was observed in canines immediately after the first treatment and 1 week after OB; this phenomenon may be explained by remnant perhydroxyl radicals in the tooth structure arising from the high concentrations of bleaching agent used (31,32).…”

O ascorbato de sódio promove a resistência de união após técnicas de clareamento dental?

“…The additives within hydrogel may reduce the efficacy of the material, thus decreasing the ascorbate diffusivity [10,14,28]. Conversely, it was reported that when chemical substances of SA are converted into hydrogel form, their drug releases rates are much slower than in the solution form, and their efficiency periods could be much longer [12]. Moreover, the application of SA solution is more difficult because its flowability and should be applied several times prior to bonding [10,17].…”

“…Most studies, which tested the effectiveness of AS in reversing compromised bond strengths, used carbamide peroxide at low concentrations [5,[7][8][9][10][11][12][13][14][15][16]20,21,25,[28][29][30]33]. It is possible that SA was more effective in teeth bleached with carbamide peroxide due the hydrogen peroxide releases a high oxygen concentration [37].…”

“…Therefore, 10% SA might be as effective as high concentrations in neutralizing the oxidizing effects of bleaching and increasing bond strengths. The 10% SA has been the most frequently concentration used in studies, being considered adequate for clinical application in solution form [5][6][7][8][9][10][11][12][13][14][15]28,30,31,33,36].…”