Checchi L, Montebugnoli L, Samaritani S
Department of Oral Surgery, School of Dentistry, University of Bologna, Italy.
J Clin Periodontol. 1998 Aug;25(8):607-11. doi: 10.1111/j.1600-051x.1998.tb02495.x.
In the present work, we evaluated (a) the influx of contaminating fluid into the air chamber when a high-speed turbine stops rotating, (b) the significance of a series of variables (type of handpiece and dental unit, shape of the bur, number of stops set on the turbine) which condition it, and (c) the time required to expel the contaminating fluid from the turbine head. Results showed that contamination takes place every time the turbine stops rotating with the bur in contact with an external fluid. The main variable affecting the influx of contaminating fluid into the air chamber of the turbine head was represented by the shape of the bur (F=54.9; p<0.01). Another significant variable was the type of handpiece and dental unit (F=7.3; p<0.01). The number of stops set on the turbine was irrelevant (F=0.03; p=n.s.). The expulsion of the contaminant from the turbine head showed 2 different exponential rates: a very rapid-elimination phase within 30 s and a slow-elimination phase between 60 and 300 s. In order to remove over 99% of the contaminant from the air chamber, a turbine had to run for more than 4-7 min depending on the type of the handpiece. In conclusion, data from the present study suggest that a significant cross-infection potential exists with high-speed handpieces whenever they are only externally scrubbed and disinfected so the internal cleaning and sterilization between patients is mandatory. The practice of flushing by running the turbines between patients should be discouraged.
在本研究中，我们评估了：(a)高速涡轮停止转动时污染液体流入气腔的情况；(b)一系列影响该情况的变量（手机和牙科设备的类型、车针形状、涡轮设定的停止次数）的重要性；(c)从涡轮机头排出污染液体所需的时间。结果表明，每当涡轮停止转动且车针接触外部液体时就会发生污染。影响污染液体流入涡轮机头气腔的主要变量是车针形状（F=54.9；p<0.01）。另一个重要变量是手机和牙科设备的类型（F=7.3；p<0.01）。涡轮设定的停止次数无关紧要（F=0.03；p无统计学意义）。从涡轮机头排出污染物呈现出两种不同的指数速率：30秒内的快速消除阶段和60至300秒之间的缓慢消除阶段。为了从气腔中去除超过99%的污染物，根据手机类型，涡轮必须运行4至7分钟以上。总之，本研究数据表明，只要高速手机仅进行外部擦洗和消毒，就存在显著的交叉感染风险，因此患者之间进行内部清洁和消毒是强制性的。应不鼓励在患者之间通过运行涡轮进行冲洗的做法。
