茶多酚、MTAD和次氯酸钠液抑制粪肠球菌及其生物膜的作用比较

摘要

目的:检测中药茶多酚、MTAD、52.5 g/L次氯酸钠抑制根管壁粪肠球菌生物膜的能力,并分析中药茶多酚作为根管冲洗液的可行性.方法:采用微孔板滴定法检测茶多酚,MTAD和52.5 g/L次氯酸钠液对粪肠球菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC),采用琼脂扩散实验检测3种抗菌剂对粪肠球菌的抑菌圈.通过建立粪肠球菌感染根管3周和6周的模型,分别用茶多酚、MTAD和52.5 g/L次氯酸钠液对粪肠球菌感染后的根管进行处理,然后对根管壁生物膜中的细菌生存情况进行定性定量分析,比较这3种根管冲洗液抗粪肠球菌生物膜的能力.结果:MIC、MBC和琼脂扩散实验显示:3组冲洗剂对粪肠球菌均有抑制作用.在粪肠球菌感染根管3周的生物膜中,MTAD和次氯酸钠液可以完全抑制粪肠球菌生物膜,茶多酚处理后虽仍有粪肠球菌生长,但明显低于生理盐水处理组的细菌生存数,差异有统计学意义(P＜0.05).在粪肠球菌感染根管6周的生物膜中,次氯酸钠液可以完全抑制细菌生长,茶多酚和MTAD作用后仍有活菌生长,但与对照组相比,细菌生存数均显示了8个log值的下降,差异有统计学意义(P＜0.05).结论:52.5 g/L次氯酸钠液具有很强的抑制根管内粪肠球菌生物膜作用,而茶多酚和MTAD也具有一定的抑制粪肠球菌生物膜的能力.%AIM; To determine the antimicrobial efficacy of tea polyphenols, MTAD and 52.5 g/L sodium hypo-chlorite (NaOCl) against Enterococcus faecalis biofilm formed on intracanal surface, and to evaluate the feasibility of tea polyphenols as an intracanal irrigation agent. METHODS: The minimal inhibitory concentration ( MIC) and minimal bacte-ricide concentration (MBC) of tea polyphenols, MTAD and NaOCl were examined using microtiter plate assay. Agar diffusion assay was used to determine inhibition zones of the three antibacterial agents. Furthermore, the root canal models infected by E. Faecalis for 3 weeks and 6 weeks were set up, and the bacterial survival in biofilm was qualitatively and quantitatively analyzed after the infected canals were treated with tea polyphenols, MTAD and NaOCl. RESULTS: All three agents showed inhibition for E. Faecalis by MIC, MBC and agar diffusion assay. In the qualitative assay with 3 - week biofilm, MTAD and NaOCl showed complete inhibition of bacterial growth, followed by tea polyphenols. Saline exerted no effects on bacterial growth, and the survival rates of E. Faecalis in tea polyphenols - treated group were significantly lower than those in saline group (P < 0.05). In the qualitative assay with 6 - week biofilm, NaOCl showed complete inhibition of E. Faecalis biofilm, whereas tea polyphenols and MTAD did not completely inhibit E. Faecalis biofilm. All groups except NaOCl showed eight log reduction when compared to control, and there was a statistical difference between the groups (P < 0. 05). CONCLUSION-52. 5 g/L, sodium hypochlorite showes maximum antibacterial activity against E. Faecalis biofilm formed nntooth substrate. Tea polyphenols and MTAD showe a certain ability of inhibition of E. Faecalis biofilm.