University of Passo Fundo, Brazil.
University of Passo Fundo, Brazil.
J Dent. 2024 Apr;143:104880. doi: 10.1016/j.jdent.2024.104880. Epub 2024 Feb 7.
To evaluate the influence of antioxidants (ATX) resveratrol, winter's bark, green tea and yerba mate on the bond strength between bleached enamel and the nanohybrid composite resin.
Bovine incisor crowns (n = 132) were randomly divided into 22 groups (n = 6) according to the application times (5, 10, 15, 30, and 60 min) of each antioxidant. Teeth restored without previous bleaching or ATX constituted the non-bleached control group (NB Ctrl) (n = 6), and teeth restored after bleaching and without ATX represented the bleached control group (B Ctrl) (n = 6). The 35 % hydrogen peroxide was applied for 45 min (3 application of 15 min) to the buccal enamel surface. ATX was used after bleaching for the specified time of each group and removed with air-water spray. The enamel was etched with 37 % phosphoric acid (30 s) and rinsed with air-water spray. The adhesive resin was applied to the enamel dry surface. Teeth were restored using 1 mm composite resin increments (10 × 10 × 3 mm) and sectioned in test specimens of 6 mm in length and 1 mm in cross-sectional area submitted to microtensile bond strength test (0.5 mm/min). The load (N) at failure was recorded, and the bond strength (σt) was calculated (MPa). The fracture area was analyzed under optical microscopy, and failures were classified as cohesive, mixed, or adhesive. Data was evaluated by Kruskal-Wallis and Dunn tests (p ≤ 0.05).
B Ctrl group presented lower σt than NB Ctrl (p < 0.001). Applying resveratrol for 5 or 10 min, winter's bark for 10 or 15 min, green tea for less than 15 min, and yerba mate for 15 min provided similar σt between bleached enamel and nanohybrid composite to the control group.
Restorative procedures performed immediately after tooth bleaching compromises adhesion. Experimental antioxidants applied to bleached enamel can increase the immediate bond strength of restorations performed directly after bleaching, with similar values to those observed in unbleached enamel.
This study presents promising results to support the use of antioxidants on the recently bleached enamel to allow adhesive tooth restorations. The immediate bonding obtained using antioxidants was similar to the one achieved in non-bleached enamel in brief application times. Green tea extract and resveratrol were able to restore the bond strength to bleached enamel in a short application time of 5 min. The reduction in the required application time holds the potential to decrease the overall duration of the clinical section, offering clinical advantages and improving the feasibility of using antioxidants on the bleached enamel prior to adhesive procedures.
评估抗氧化剂（ATX）白藜芦醇、冬柏树皮、绿茶和马黛茶对漂白牙釉质与纳米混合复合树脂之间粘结强度的影响。
根据每种抗氧化剂的应用次数（5、10、15、30 和 60 分钟），将牛切牙冠（n = 132）随机分为 22 组（n = 6）。未经先前漂白或 ATX 处理的牙齿构成非漂白对照组（NB Ctrl）（n = 6），经漂白后未使用 ATX 的牙齿代表漂白对照组（B Ctrl）（n = 6）。35%过氧化氢应用于颊侧牙釉质表面 45 分钟（3 次，每次 15 分钟）。漂白后，各实验组用 ATX 处理指定时间，并用空气水喷雾去除。用 37%磷酸酸蚀牙釉质 30 秒（30 s），并用空气水喷雾冲洗。将粘结树脂涂覆于牙釉质干燥表面。用 1 毫米复合树脂增量（10×10×3 毫米）进行修复，在长度为 6 毫米、横截面面积为 1 毫米的测试标本上进行微拉伸粘结强度测试（0.5 毫米/分钟）。记录失效时的负载（N），并计算粘结强度（σt）（MPa）。在光学显微镜下分析断裂面积，并根据断裂模式将失效分为内聚性、混合性或粘着性。采用 Kruskal-Wallis 和 Dunn 检验（p ≤ 0.05）对数据进行评估。
B Ctrl 组的 σt 明显低于 NB Ctrl（p < 0.001）。白藜芦醇处理 5 分钟或 10 分钟，冬柏树皮处理 10 分钟或 15 分钟，绿茶处理少于 15 分钟，马黛茶处理 15 分钟，均可使漂白牙釉质与纳米混合复合树脂之间的粘结强度与对照组相似。
牙漂白后立即进行修复程序会损害粘结性。应用于漂白牙釉质的实验性抗氧化剂可增加牙漂白后直接修复的即刻粘结强度，其值与未漂白牙釉质相似。
本研究提供了有前景的结果，支持在最近漂白的牙釉质上使用抗氧化剂以进行牙粘结修复。使用抗氧化剂获得的即刻粘结强度与在短时间应用的非漂白牙釉质相似。绿茶提取物和白藜芦醇能够在 5 分钟的短应用时间内恢复对漂白牙釉质的粘结强度。应用时间的减少有可能缩短临床操作的总时间，为临床带来优势，并提高在粘结操作之前在漂白牙釉质上使用抗氧化剂的可行性。
