4种消毒剂对治疗台水路系统细菌生物膜的消毒效果研究

Study on the disinfection effect of four kinds of disinfectants on bacterial biofilms in dental unit waterlines

目的评估口腔科治疗台水路系统(DUWLs)内细菌生物膜的特点及不同消毒剂的消毒效果。方法通过场发射扫描电镜(FE-SEM)观察DUWLs内壁细菌生物膜的超微结构,通过Remel识别系统对细菌菌落数和种类进行分析。分别用3%过氧化氢、0.2%过氧化氢纳米银、5.25%次氯酸钠和0.12%氯己定灌洗DUWLs 5 min,静置10 min,再用无菌水冲洗1 min,每周重复操作,共4周。在处理前和处理后24 h,用激光共聚焦扫描显微镜评估生物膜的结构和活菌比例。结果FE-SEM图像显示DUWLs内壁有丰富的细菌生物膜,共12种条件致病菌,革兰阴性条件致病菌为优势菌。所有DUWLs中的细菌数量在用4种消毒剂处理后迅速减少,但随着时间的推移逐步增加。0.2%过氧化氢纳米银的消毒效果比其他消毒剂更持久(P<0.05)。结论DUWLs内壁存在细菌生物膜,革兰阴性条件致病菌为优势菌,0.2%过氧化氢纳米银对DUWLs细菌生物膜具有良好的消毒效果。

Objective To evaluate the characteristics of bacterial biofilms in dental unit waterlines(DUWLs)and the disinfection effects of different disinfectants.Methods The ultrastructure of bacterial biofilms on the inner wall of DUWLs was observed using field emission scanning electron microscopy(FE-SEM),and the number and types of bacterial colonies were analyzed using the Remel identification system.DUWLs were washed respectviely with 3%hydrogen peroxide,0.2%hydrogen peroxide nanosilver,5.25%sodium hypochlorite and 0.12%chlorhexidine for 5 min,incubated for 10 min,and then rinsed with sterile water for 1 min.The operation was repeated every week for a total of 4 weeks.The structure of biofilms and the ratio of viable bacteria were assessed using confocal laser scanning microscopy before and 24 h after the operation.Results FE-SEM images showed abundant bacterial biofilms on the inner wall of DUWLs,with a total of 12 types of conditional pathogenic bacteria,and Gram-negative conditional pathogenic bacteria were the dominant bacteria.The number of bacteria in all DUWLs were decreased after treatment with four kinds of disinfectants,but gradually increased over time.The disinfection effect of 0.2%hydrogen peroxide nanosilver was more durable than other disinfectants(P<0.05).Conclusion There is a bacterial biofilm on the inner wall of DUWLs,and Gram-negative pathogenic bacteria are the dominant bacteria.0.2%hydrogen peroxide nanosilver has a good disinfection effect on the bacterial biofilm of DUWLs.