Can green tea be used to reverse compromised bond strength after bleaching?

Abstract

The objective of this study was to evaluate the antioxidant effect of green tea on microtensile bond strength (μTBS) to bleached enamel. Forty-two human third molars were randomly divided into six experimental groups (n = 7 each group): group 1, no treatment; group 2, bleaching (10% carbamide peroxide); group 3, bleaching + 10% sodium ascorbate gel (SA); group 4, bleaching + 10% green tea gel (GT); group 5, SA; and group 6, GT. In groups 2, 3, and 4, bleach was applied onto the enamel surface for 6 h, every day for 14 d. In groups 3 and 5, SA was applied for 1 h; and in groups 4 and 6, GT was applied for 1 h. Immediately after treatment, the specimens were bonded with Adper Single Bond 2 and Filtek Z350 XT. The μTBS of the specimens was tested using a universal testing machine. Fracture mode analysis of the bonded enamel surface was performed using scanning electron microscopy. The mean μTBS values for each group were: group 1, 33.2 ± 5.8 MPa; group 2, 22.6 ± 5.5 MPa; group 3, 30.0 ± 5.2 MPa; group 4, 31.6 ± 3.8 MPa; group 5, 29.1 ± 4.2 MPa; and group 6, 32.2 ± 4.5 MPa. All groups had a higher percentage of mixed failures. In conclusion, green tea can be used as an alternative antioxidant on bleached enamel before bonding procedures.

The effect of green tea on the shear strength of brackets after home whitening treatment

“…structure have been studied, including sodium ascorbate [6,7], catalase [8], alphatocopherol [9], grape seed extract [10], and, more recently, green tea [11,12]. Although sodium ascorbate is the most studied antioxidant [6,7,13], its use is still not clinically feasible.…”

“…Polyphenolic compounds from green tea are antioxidants used in modern dentistry [11,14]. Green tea, which is extracted from the plant Camellia sinensis, contains various catechin compounds.…”

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

“…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].…”

“…Perhaps, the different kinetics degradation of bleaching agents type may influence the antioxidant ability of SA. Studies that did not observe the effectiveness of AS used high concentrations of peroxide or long time exposure of bleaching agent [32][33][34][35][36].…”

Effect of waiting time for placing resin composite restorations after bleaching on enamel bond strength

“…Consequently, polymerization of resin-based materials (e.g., dental adhesives, resin composites, and resin cements) may be compromised since oxygen is a well-known inhibitor of polymerization reactions [5], thus affecting negatively the bond strength between resin materials and the tooth. Taking this into account, the literature advices that it would be prudent to wait for a period of time between the end of bleaching treatment and placement of adhesive restorations, unless if antioxidant substances are applied on the tooth in an attempt to completely remove the remaining oxygen molecules [4,[6][7][8][9].…”