评价两种低温等离子体对粪肠球菌生物膜作用的体外实验研究

目的 比较辉光放电和介质阻挡放电两种低温等离子体装置产生的大气压低温等离子体对根管内粪肠球菌生物膜的杀菌效果。方法 在120颗离体牙的根管内部培养粪肠球菌生物膜，培养时间为7 d。将离体牙随机分为12个组，其中，10组分别接受介质阻挡放电和辉光放电这两种大气压低温等离子体装置处理离体牙根管，每种装置各处理5组，每组处理时间分别为2、4、6、8、10 min；另外2组为两种不同装置的单纯气体对照组。采用菌落形成单位计数法比较两种装置对根管内生物膜的杀菌效果，通过光谱测量仪分析两种装置的等离子体活性成分。结果 介质阻挡放电装置比辉光放电装置对根管内粪肠球菌生物膜的杀菌效果更好，不同时间段二者存活的细菌数量均有统计学差异（P<0.05），而且随着处理时间延长优势更加明显。发射光谱显示两种装置的低温等离子体活性物质成分一致，但激发态Ar原子的群峰总体上表现为介质阻挡放电装置是辉光放电装置的2倍。结论 介质阻挡放电装置产生的低温等离子体杀灭根管内粪肠球菌生物膜更具优势。

Evaluation of two different cold plasma treatments on root canal infected with Enterococcus faecalis biofilms in vitro

 Objective  To compare the bactericidal efficacy of two different cold plasma (glow discharge and dielectric barrier discharge) treatments on root canal infected with Enterococcus faecalis biofilms in vitro. Methods  One hundred and twenty teeth infected with Enterococcus faecalis biofilm in the roots for seven days were divided into twelve groups randomly. Two served as negative control group (gas only, no discharge) . Five were teeth treated by dielectric barrier discharge cold plasma and the other five were treated by glow discharge cold plasma. The treatment time in each five groups was 2, 4, 6, 8 and 10 min, respectively. The disinfection of Enterococcus faecalis biofilm was evaluated by colony forming unit (CFU) counting. The plasma component produced by different devices was analyzed by optical emission spectroscopy (OES) . Results  Comparing the two plasma treatments, the plasma produced by dielectric barrier discharge had better bactericidal effect than that produced by glow discharge at different treatment time (P<0.05) . The advantage was obvious with the time getting longer. The OES indicated that active components of the two type plasmas were similar. But the peak of excited Ar atom of dielectric barrier discharge was twice as that of glow discharge. Conclusion  The cold plasma produced by dielectric barrier discharge has more bactericidal efficiency in the treatment of root canal infected with Enterococcus faecalis biofilms.