Department of Orthodontics, Faculty of Dentistry, Mansoura University, Mansoura, 35516, Mansoura, Egypt.
Department of Dental Biomaterials, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
BMC Oral Health. 2023 Apr 2;23(1):197. doi: 10.1186/s12903-023-02894-3.
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.
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.
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).
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.
有研究报道，在经过氧化氢漂白后立即粘结托槽会导致粘结强度降低。本研究比较了三种抗氧化剂（即α-生育酚、绿茶提取物和抗坏血酸钠）的有效性，以逆转漂白效果，并作为延迟粘结的替代方法。
共 105 颗人离体前磨牙被随机分为 7 组（每组 15 颗），包括第 1 组未漂白对照组和 6 个实验组，每组实验组均用 40%过氧化氢分 3 次、每次 15 分钟漂白。实验组 2 在漂白后立即粘结，实验组 3 和实验组 4 分别延迟 1 周和 2 周粘结，同时将标本置于 37°C 的人工唾液中。实验组 5、实验组 6 和实验组 7 在漂白后立即用 10%的α-生育酚、绿茶提取物和抗坏血酸钠溶液处理 15 分钟。标本在 5 至 55°C 之间进行 500 次热循环，在粘结后 24 小时后停留 30 秒，然后进行剪切粘结强度测试。用粘结残留指数评估断裂模式。采用单因素方差分析、Kruskal-Wallis H 检验和事后 Tukey Honestly Significant Difference 检验比较数据。对有统计学意义的结果进行两两比较，并对 p 值进行 Bonferroni 校正调整，p 值≤0.050。
立即粘结组和 1 周延迟组的剪切粘结强度显著低于对照组（p<0.001）。然而，2 周延迟组、抗氧化剂处理组和对照组之间无显著差异（p>0.05）。
用 10%α-生育酚、绿茶提取物或抗坏血酸钠处理 15 分钟可恢复 40%过氧化氢漂白后的剪切粘结强度，作为延迟粘结的替代方法。
