Montebugnoli Lucio, Dolci Giovanni, Spratt David Alexander, Puttaiah Raghunath
Department of Oral Science, University of Bologna, via S. Vitale 59, 40125 Bologna, Italy.
Am J Dent. 2005 Aug;18(4):270-4.
To evaluate the efficacy of anti-retraction valves; and to compare between-patient flushing with water and with using a chemical treatment to control patient-to-patient contamination through dental unit waterlines (DUWL).
For the first aim, nine new antiretraction valves from three different manufacturers were utilized. Each valve was installed along the water line connecting the high-speed handpiece to the dental unit. The handpieces were made to run and stop in a container filled with a solution of about 7 log10/mL of Bacillus subtilis spores (used as a marker) and retraction of spores was measured. Subsequently, all nine valves were installed in dental units in use in private offices, and all tests repeated after 15, 30 and 60 working days. For the second aim, the efficacy of mechanical flushing (30 seconds for each instrument) was compared with that of mechanical flushing in combination with pressurized air and of a between-patient disinfecting procedure (2 minutes contact with TAED and persalt utilizing an "autosteril" system). Before each test (10 tests for each procedure), known concentrations of Pseudomonas aeruginosa (ATCC 27853) suspension (4 to 7 log10cfu/mL) was loaded in the DUWL and let sit for 20 minutes.
In the anti-retraction valve experiment, at baseline only one anti-retraction valve showed a failure in opposing fluid retraction. After 15 days, three valves, after 30 days, six valves, and after 60 days, eight valves showed failure. In the flushing experiment, a highly significant linear correlation (r =.9178) was found between values before and after mechanical flushing. Post flush log10cfu/mL values showed the removal of about only 1 log10cfu/mL of the microorganisms (only about 10% in absolute counts). On the other hand, no cfu/mL was detected in waterlines after the "autosteril" disinfecting cycles.
评估防回流阀的功效；并比较使用水进行患者间冲洗以及使用化学处理来控制通过牙科设备水线（DUWL）造成的患者间污染的效果。
对于第一个目标，使用了来自三个不同制造商的九个新型防回流阀。每个阀门都安装在连接高速手机与牙科设备的水线上。使手机在装满约7 log10/毫升枯草芽孢杆菌孢子溶液（用作标记物）的容器中运行和停止，并测量孢子的回流情况。随后，将所有九个阀门安装在私人诊所正在使用的牙科设备中，并在15、30和60个工作日后重复所有测试。对于第二个目标，将机械冲洗（每个器械冲洗30秒）的效果与机械冲洗结合加压空气的效果以及患者间消毒程序（使用“自动消毒”系统与TAED和过氧酸盐接触2分钟）的效果进行比较。在每次测试前（每个程序进行10次测试），将已知浓度的铜绿假单胞菌（ATCC 27853）悬浮液（4至7 log10cfu/毫升）注入DUWL中并静置20分钟。
在防回流阀实验中，基线时只有一个防回流阀在阻止液体回流方面出现故障。15天后，有三个阀门出现故障，30天后，有六个阀门出现故障，60天后，有八个阀门出现故障。在冲洗实验中，发现机械冲洗前后的值之间存在高度显著的线性相关性（r = 0.9178）。冲洗后log10cfu/毫升的值显示仅去除了约1 log10cfu/毫升的微生物（绝对计数仅约10%）。另一方面，在“自动消毒”消毒循环后，水线中未检测到cfu/毫升。
