Human Biology Department, College of Dentistry, University of Toronto, Toronto, ON, Canada.
J Appl Oral Sci. 2013 Mar-Apr;21(2):203-7. doi: 10.1590/1678-7757201302430.
To test the inhibitory growth activity of green tea catechin incorporated into dental resins compared to resins containing the broad-spectrum antimicrobial compound chlorhexidine against Streptococcus mutans in vitro.
The minimum inhibitory concentrations (MICs) of epigallocatechin-gallate (EGCg) and chlorhexidine (CHX) were determined according to the microdilution method. Resin discs (5 mm × 3 mm) were prepared from Bis-GMA/TEGDMA (R1) and Bis-GMA/CH3Bis-GMA (R2) comonomers (n=9) containing: a) no drug, b) EGCg, c) CHX. Two concentrations of each drug (0.5× MIC and 1× MIC) were incorporated into the resin discs. Samples were individually immersed in a bacterial culture and incubated for 24 h at 37°C under constant agitation. Cell viability was assessed by counting the number of colonies on replica agar plates. Statistical analysis was performed using one-way ANOVA, Tukey and Student t-tests (α=0.05).
Both resins containing EGCg and CHX showed a significant inhibition of bacterial growth at both concentrations tested (p<0.05). A significantly higher inhibition was observed in response to resins containing CHX at 0.5× MIC and 1× MIC, and EGCg at 1× MIC when compared to EGCg at 0.5× MIC. Also, EGCg at 0.5× MIC in R1 had a significantly higher growth inhibition than in R2.
Both EGCg and CHX retained their antibacterial activity when incorporated into the resin matrix. EGCg at 1× MIC in R1 and R2 resins significantly reduced S. mutans survival at a level similar to CHX. The data generated from this study will provide advances in the field of bioactive dental materials with the potential of improving the lifespan of resin-based restorations.
测试绿茶儿茶素与广谱抗菌化合物氯己定相比，掺入牙科树脂后对体外变形链球菌的生长抑制活性。
根据微量稀释法确定表没食子儿茶素没食子酸酯（EGCg）和氯己定（CHX）的最小抑菌浓度（MIC）。从 Bis-GMA/TEGDMA（R1）和 Bis-GMA/CH3Bis-GMA（R2）共单体（n=9）制备 5mm×3mm 的树脂圆盘，含有：a）无药物，b）EGCg，c）CHX。将两种药物浓度（0.5×MIC 和 1×MIC）分别掺入树脂盘中。将样品单独浸入细菌培养物中，在 37°C 下以恒定搅拌孵育 24 小时。通过在复制琼脂平板上计数菌落数来评估细胞活力。使用单向方差分析、Tukey 和学生 t 检验（α=0.05）进行统计分析。
两种含有 EGCg 和 CHX 的树脂在测试的两种浓度下均表现出对细菌生长的显著抑制作用（p<0.05）。与 0.5×MIC 和 1×MIC 时的 EGCg 相比，在 0.5×MIC 和 1×MIC 时含 CHX 的树脂以及在 1×MIC 时含 EGCg 的树脂观察到更高的抑制作用。此外，与 R2 相比，R1 中 EGCg 0.5×MIC 时的生长抑制作用显著更高。
EGCg 和 CHX 掺入树脂基质中时保留其抗菌活性。R1 和 R2 树脂中 1×MIC 的 EGCg 可显著降低变形链球菌的存活率，其水平与 CHX 相似。本研究产生的数据将为具有延长树脂基修复体寿命潜力的生物活性牙科材料领域提供进展。
