零回吸牙科涡轮机微生物回吸污染状况的实验研究
A Bacteriological Study of Contamination of Zero Suck-back Dental Handpiece and Tube
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摘要:
目的 通过细菌学实验,比较牙科用零回吸涡轮机与普通涡轮机在使用中的微生物污染状况和零回吸涡轮机的防回吸能力,为临床使用提供理论依据。 方法 零回吸涡轮机和普通涡轮机各10支,在不安装车针、菌液液面下回吸和安装车针、菌液液面上回吸(1次和3次)1& #215;107、1& #215;108、1& #215;109 cfu/mL鼠伤寒沙门菌(TA97标准菌株)配制成菌悬液,采集涡轮机内部及连接管道不同时段的冲洗液,培养计数,比较细菌污染状况。 结果 零回吸涡轮机的回吸现象较普通涡轮机减弱,在1& #215;107 cfu/mL菌液浓度下,零回吸涡轮机尾部采样培养获得250& #177;71菌落数,普通涡轮机尾部采样培养获得944& #177;156菌落数。模拟临床使用情况下,零回吸涡轮机的内部和连接管道未检测到试验菌株;普通涡轮机可检测到涡轮机内部和连接管道内的回吸菌株,在空踩60 s后管道内回吸细菌排空;普通涡轮机回吸3次较1次可回吸更大量的细菌,在1& #215;109 cfu/mL菌液浓度下,回吸1次涡轮机头部采样培养获得762& #177;292菌落数,回吸3次涡轮机头部采样培养获得1925& #177;106菌落数。 结论 零回吸涡轮机可避免工作环境污物的回吸,避免交叉感染;使用普通涡轮机必须做到使用前后空踩冲洗管道。 Abstract:Objective To compare the performance and contaminating level of zero suck-back dental handpiece with conventional handpiece through bacteriological experiments for clinical practice. Methods Ten zero suck-back handpieces and ten conventional handpieces sucked (n=1 and 3)without bits and in the solution, or with bits and on the surface of culture solution of 107 cfu/mL, 108 cfu/mL, and 109 cfu/mL Salmonella typhimurium TA97 respectively to prepare the bacterium suspensions. The flushing fluid of handpieces and tubes at different time periods was collected for bacterial culture to count the number of bacteria and then compare the contaminating levels of different units. Results Compared with conventional handpiece, zero suck-back handpiece exhibited less resorption. As sucked with Salmonella typhimurium of 1& #215;107 cfu/ml concentration, 250& #177;71 bacterial colonies of tester strain had been detected in the cultured specimen collected from the rear of the zero suck-back handpieces, while 944& #177;156 had been detected in the cultured specimen collected from the rear of the conventional ones. The tester strain had not been detected in zero suck-back handpieces and tubes under simulated clinical uses, but was detected in conventional ones. After flushing 60 s, no strain could be detected in conventional handpieces and tubes. Compared with one resorption, 3 times of resorption by conventional handpieces produced more bacteria. As sucked with Salmonella typhimurium of 1& #215;109 cfu/ml concentration, 762& #177;292 bacterial colonies of tester strain had been detected in the cultured specimen collected from the head of the zero suck-back handpieces after 1 time of resorption, while 1 925& #177;106 had been detected in the cultured specimen collected from the head of the conventional ones after 3 times of resorption. Conclusion The use of zero suck-back handpieces could avoid resorption of contaminating substances and thus, reduce the possibility of cross infection. Tubes of dental units should be flushed before and after use of conventional handpieces.
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