口腔综合治疗台水路空踩放水各量点的细菌污染状况

背景:每天空踩口腔综合治疗台水路放水作为简单、花费少的减少口腔综合治疗台水路污染的方法,官方感控指南建议每治疗完一例患者后需要空踩高速涡轮机30 s放水.但由于每台口腔综合治疗台的出水速度不同,以时间作为放水依据往往欠精确.目的:评估空踩口腔综合治疗台水气枪和高速涡轮机水路放水不同量点的细菌污染状况,以期为临床探索实际操作性好的水路放水方案提供依据.设计、时间及地点:横断面调查,于2007-05/2008-03完成实验及数据整理,取样于广东省口腔医院各临床科室完成,细菌学检测于南方医科大学公共卫生与热带医学学院微生物实验室完成.材料:普通营养琼脂、血平板、微生物生化反应鉴定系统、链球菌凝集试验试剂盒、革兰染色液等购自广东环凯微生物试剂公司.方法:选取某口腔医院80张口腔综合治疗台水气枪和高速涡轮机水路取水样,取样时间为2007-05/10隔周星期五下班后,每机连续取3个2 mL水样.采用常规微生物分离鉴定技术进行细菌学检测.主要观察指标:水样中细菌浓度及葡萄球菌、链球菌和放线菌的检出率.结果:口腔综合治疗台水气枪和高速涡轮机水路水样中细菌浓度中位数为5.67×10 ~2cfu/mL,二者3个2 mL水样的细菌浓度差异无显著性意义(P>0.05).口腔综合治疗台水路第3个2 mL水样较前2个2 mL水样中葡萄球菌浓度高(P<0.05),而3个2 mL水样中链球菌和放线菌的浓度差异无显著性意义(P>0.05).结论:以空踩口腔综合治疗台水气枪和高速涡轮机水路放水不同量点为依据较以时间点为依据探索水路放水方案的实际操作性更好,但最佳放水量的确定还有待进一步研究.

Microbial contamination in dental unit waterlines with different flushing volume

BACKGROUND:Daily flushing of dental unit waterlines (DUWLs) is believed to be the least expensive and simplest method for reducing the level of microbial contamination in DUWLs.Authorities' guidelines suggest that high-speed handpieces should be run to discharge water for 30 seconds after use on each patient.However,the guideline is inaccurate for clinicians according to the time-dependent flushing since the maximum flow rate of flushing water varied from dental chair units (DCUs).OBJECTIVE:To assess the level of microbial contamination in water effluent from the air-water syringe and the high-speed handpiece line of DCUs and prevalence of three species of bacteria detected in DUWLs at each flushing volume.Thus,practical water flushing measures could be proposed according to the effect of volume-dependent dental unit waterline flushing on the microbial contamination in DUWLs.DESIGN,TIME AND SETTING:A cross-sectional investigation was designed and conducted in Guangdong Provincial Stomatological Hospital and Laboratory of Microbiology,School of Public Health and Tropical Medicine,Southern Medical University between May 2007 and March 2008.MATERIALS:The materials used in this investigation including nutrient agar,blood plates,biochemical testing kit,agglutination testing kit and Gram staining agents.These materials were supported by Guangdong Huankai Microbiological Science and Technology Ltd.METHODS:Water sampling was conducted at 80 DCUs in a stomatologicel hospital.A total of 6 mL,2 mL for once sampling,of continuous water flushing from the air-water syringe and the high-speed handpiece line of each DCU respectively were collected aseptically after the finish of the daily clinical work on every second Friday,between May 2007 and October 2007.Standard isolation and identification technique of bacteria was adopted.MAIN OUTCOME MEASURES:Concentration of bacteria and prevalence of three species of bacteria in water effluent from the air-water syringe and the high-speed handpiece line of DCUs at each flushing volume were evaluated.RESULTS:The median concentration of bacteria in water effluent from either the air-water syringe or the high-speed handpiece line of DCUs was 5.67×10~2 cfu/mL,and there were no statistical differences among microbial concentrations of first three 2-mL flushing water samples (P>0.05).Prevalence of Staphylococcus spp.from the third 2-mL flushing water sample demonstrated an obviously higher level than that of Staphylococcus spp.from the first two 2-mL (P < 0.05),while prevalence of Streptococcus spp.and Actinomycete spp.kept at a relative stable level (P > 0.05) at each flushing volume.CONCLUSION:Volume-dependent water flushing procedure stays a more practical measure for reducing microbial contamination in DUWLs rather than time-dependent flushing,but the volume of flushing water needs to be further evaluated.