超声波刮治机所引发气溶胶的时空分布特性

Spatiotemporal Distribution of Aerosols Generated by Using Ultrasonic Scaling Instrument

对牙周科诊疗过程中使用超声波刮治机所引发的气溶胶(粒径为0.3~10.0μm)浓度和数量随时空的分布特性进行了现场测试.在3个不同高度处,即患者呼吸区(0.8 m高)、医护人员呼吸区(1.1 m高)和过渡区(0.9 m高)以及距患者口腔水平距离0.8 m范围内设置采样点.在诊疗期间使用强吸设备(内径为6 mm)的情况下,环绕患者口腔水平距离0.8 m范围内的气溶胶质量浓度(以下简称浓度)均值大约为300μg/m^(3),明显高于室内空气质量标准中所规定的限值.沿高度方向,医护人员呼吸区高度受喷溅气溶胶影响较小.沿水平方向,气溶胶浓度沿不同方位的分布特性近似,并且随距离的增加衰减不明显.与喷砂洁牙机相比,超声波刮治机所引发的气溶胶粒径以小于1μm为主并且气溶胶动量较小,这表明不同诊疗设备可能造成完全不同的气溶胶污染风险.因此,牙周科诊室呼吸道传染病交叉感染风险较高,现有防控措施(如强吸设备)不能有效限制气溶胶喷溅,仍需研发新型防控技术和装备.

The study performed an on-site measurement of the spatiotemporal distribution of aerosols at the range of 0.3~10.0μm,generated during the use of an ultrasonic scaling instrument in the dental treatment.The mass concentration and number of aerosols were monitored within 0.8 m away from the patient’s mouth at three vertical heights from the floor,namely 0.8 m(the height of the patients’mouth),0.9 m,and 1.1 m(the height of the medical staffs’mouth).The mean concentration of aerosols in the area within 0.8 m away from the patient′s mouth is approximately 300μg/m^(3),which is higher than the allowed thresholds in indoor spaces.This concentration is measured when a suction system with an inner diameter of 6 mm is used.Vertically,the medical staff′s respiratory zone is less affected by the spattering during the dental treatment.Horizontally,the concentration of aerosols is similar along different directions and the attenuation is not obvious along the distance.Compared with powder jet handpieces,the diameter of aerosols generated by an ultrasonic scaling instrument is mostly less than 1μm and the initial momentum of aerosols is lower obviously,indicating different levels of pollution risk of aerosols generated by different instruments.The results indicate that the present control measures,including the suction system,are not effective to prevent the spattering of aerosols generated by ultrasonic scaling instruments.New control measures should therefore be developed to limit the high risk of cross-infection in dental hospitals and clinics.