次氯酸钠对口腔综合治疗台水路消毒效果的研究

A Study of the Disinfection Effect of Sodium Hypochlorite on the Dental Unit waterlines

目的观察7.5‰次氯酸钠对口腔综合治疗台水路(dental unit water lines,DUWLs)的消毒效果,并通过电镜观察消毒前后旧管路及全新管路的生物膜结构变化,为DUWLs的有效消毒方案提供参考。方法随机选取13台使用3.5年的A-dec口腔综合治疗台(dental chair unit,DCU)作为研究对象,用7.5‰的次氯酸钠进行水路消毒,对消毒前即刻、消毒后0、24、48 h的水样进行菌落计数;同时随机选取两台DCU对消毒前即刻、消毒后0、24、48 h水气枪处出水管管路内壁进行电镜生物膜观察;上面两台DCU在更换全新管路后进行30 d的水样菌落计数和60 d的生物膜电镜观察。结果使用3.5年的DUWLs消毒后即刻与消毒前相比,细菌菌落数量明显降低,差异有统计学意义(P<0.01),消毒后24 h与消毒后即刻相比,差异无统计学意义(P>0.05),均<100CFU/ml,符合北京市口腔综合治疗台消毒技术规范诊疗用水标准;电镜下观察消毒后DCU内壁的生物膜结构受到一定程度破坏,但是基质及部分细菌仍然存在;新管路消毒后30 d内的细菌菌落计数基本符合诊疗用水标准,全新管路60天内未见成熟生物膜形成。结论7.5‰的次氯酸钠消毒液能有效地降低DUWLs内的菌落总数,并破坏管壁的生物膜结构,起到较好的消毒效果,但对不同使用年限的DCU,为达到北京市诊疗用水标准,消毒频次应有所区别。

Objective To observe the disinfection effect of 7.5‰sodium hypochlorite on dental unit water lines(DUWLs),and observe the changes of biofilm structure of old and new pipes before and after disinfection through electron microscopy,so as to provide reference for effective disinfection of DUWLs.Methods Thirteen A-dec dental chair units,which have been used for 3.5 years,were randomly selected as the research objects,and 7.5‰sodium hypochlorite was used for disinfection.The colonies were counted in the water samples immediately before disinfection and 0,24 and 48 h after disinfection Two DCUs were randomly selected to observe the biofilm before and after disinfection at 0,24,and 48 hours by scanning electron microscopy(SEM).The bacterial colony count of the water samples was counted for 30 days and the biofilm was observed by SEM for 60 days after the two DUWLs was replaced.Results Immediately after disinfection,the number of bacterial was significantly lower compared to before disinfection,and there was significant between them(P<0.01).The difference between 24 hours after disinfection and immediately after disinfection was not statistically significant(P>0.05).The biofilm structure on the inner wall of the DUWLs was partially destroyed for 48 hours after disinfection under SEM,but the matrix and some bacteria still existed.The bacterial colony count within 30 days after disinfection of the new waterlines basically met the local standard in Beijing,which is less than 100 CFU/mL,and no mature biofilm was formed within 60 days.Conclusion The 7.5‰sodium hypochlorite can effectively reduce the total number of colonies in DUWLs and destroy the biofilm structure of the tube wall,and play a good disinfection effect.However,the disinfection frequency should be different for DCUs with different years of use to meet the local standards in Beijing.