Universidade de Fortaleza - Unifor, Dentistry School, Fortaleza, CE, Brazil.
Universidade Federal do Ceara - UFC, Faculty of Pharmacy, Nursing and Dentistry, Department of Operative Dentistry, Fortaleza, CE, Brazil.
Braz Oral Res. 2021 Nov 19;35:e108. doi: 10.1590/1807-3107bor-2021.vol35.0108. eCollection 2021.
The present study sought to evaluate the protective effect of Epigallocatechin-3-gallate (EGCG) and commercial green tea (GT) on eroded dentin using in vitro and in situ experimental models. For the in vitro experiment, matrix metalloproteinases (MMPs) were extracted from demineralized human coronary dentin powder (citric acid, pH 2.3) and assessed via a colorimetric assay and electrophoresis in gelatin. The gels were exposed to buffers with: control (no treatment), 0.05% sodium fluoride (NaF), 0.12% chlorhexidine digluconate (CHX), GT infusion, and 0.1% EGCG, and their respective activity was analyzed by zymography. For the in situ experiment, 20 healthy volunteers (aged 20-32 years) participated in this single-center, blind, crossover study. The subjects wore upper removable devices containing four human dentin blocks. Erosive challenge (coke-1 min) was performed four times/day/5 days. Blocks were treated for 1 min with: control (No treatment), 0.05% NaF, 0.1% EGCG, and GT. Thereafter, the specimens were subjected to stylus profilometry and SEM. ANOVA was used to evaluate dentin roughness and wear, with a significance level of 5%. In the zymography analysis, 0.12% CHX, GT, and 0.1% EGCG were found to inhibit the action of MMPs; however, in the colorimetric assay, only green tea inhibited the activity of MMPs. There were no significant differences observed in dentin roughness or wear (p > 0.05). Herein, EGCG and GT inhibited the activity of endogenous proteases, resulting in protection against erosion-induced dentin damage; however, they could not prevent tooth tissue loss in situ.
本研究旨在通过体外和体内实验模型评估表没食子儿茶素没食子酸酯（EGCG）和市售绿茶（GT）对脱矿牙本质的保护作用。体外实验中，从脱矿的人冠状动脉牙本质粉末（柠檬酸，pH2.3）中提取基质金属蛋白酶（MMPs），通过比色法和明胶电泳进行评估。将凝胶暴露于以下缓冲液中：对照（无处理）、0.05%氟化钠（NaF）、0.12%葡萄糖酸氯己定（CHX）、GT 输注液和 0.1%EGCG，并通过酶谱法分析其各自的活性。体内实验中，20 名健康志愿者（年龄 20-32 岁）参加了这项单中心、盲法、交叉研究。研究对象佩戴含有四个人类牙本质块的上可移动装置。每天进行 4 次/5 天的腐蚀性挑战（可乐 1 分钟）。用以下方法处理牙本质块 1 分钟：对照（无处理）、0.05%NaF、0.1%EGCG 和 GT。然后，对标本进行触针轮廓仪和 SEM 分析。使用方差分析评估牙本质粗糙度和磨损，显著性水平为 5%。在酶谱分析中，发现 0.12%CHX、GT 和 0.1%EGCG 抑制 MMPs 的作用；然而，在比色法中，只有绿茶抑制 MMPs 的活性。牙本质粗糙度或磨损没有显著差异（p>0.05）。在此，EGCG 和 GT 抑制内源性蛋白酶的活性，从而防止侵蚀性牙本质损伤；然而，它们不能防止原位牙齿组织丢失。
