Li Xiujie, Mak Cheuk Ming, Ma Kuen Wai, Wong Hai Ming
Department of Building Services Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.
Faculty of Dentistry, The University of Hong Kong, Pok Fu Lam, Hong Kong Island, Hong Kong, China.
Sustain Cities Soc. 2021 Nov;74:103134. doi: 10.1016/j.scs.2021.103134. Epub 2021 Jul 9.
In time, dental health care has slowly expanded beyond emergency treatment to treat oral diseases. How to reduce the cross-transmission risk in dental surgery has raised much more attention. Considering the lack of consistency of fallow time (FT) in its necessity and duration, the highly sensitive laser light scattering method has been proposed to visualize the airborne lifetime and decay rate of suspended particles in the dental surgery environment. The FT is defined as when the number of suspended particles drops to the level that the next patient can safely enter after the aerosol-generating procedures (AGPs). The ultrasonic scaling was performed in the mock-up experimental dental clinic with 6 air changes per hour (ACH), and the instantaneous moments of the droplets were recorded by a high-speed camera. Without any mitigation measures, the estimated FT in the single dental surgery environment with 6 ACH was in the range of 27-35 min, significantly affecting the number of daily dental services. Despite the cooperation of high-volume evacuation (HVE [IO]) cannot eliminate the FT to zero minutes, the equipment could reduce the required FT by 3-11 min for the suspended particles reducing the baseline levels. Owing to the longer airborne lifetime of suspended particles, the relevant protection equipment, especially respiratory protection, is quite essential in dental surgery. The obtained results of this study will provide evidence to establish the revised FT in dental surgery guidelines and protect the health and wellbeing of urban dwellers.
随着时间的推移，牙科医疗保健已逐渐从紧急治疗扩展到口腔疾病的治疗。如何降低牙科手术中的交叉传播风险受到了更多关注。考虑到休耕时间（FT）在必要性和持续时间上缺乏一致性，人们提出了高灵敏度激光散射法来可视化牙科手术环境中悬浮颗粒的空气传播寿命和衰减率。FT的定义是悬浮颗粒数量下降到下一位患者在产生气溶胶程序（AGP）后能够安全进入的水平。在每小时换气6次（ACH）的模拟实验牙科诊所中进行超声洁治，并通过高速摄像机记录液滴的瞬间情况。在没有任何缓解措施的情况下，每小时换气6次的单一牙科手术环境中的估计FT在27 - 35分钟范围内，这显著影响了每日牙科服务的数量。尽管大容量抽吸（HVE [IO]）的配合不能将FT消除到零分钟，但该设备可以将悬浮颗粒的所需FT减少3 - 11分钟，从而降低基线水平。由于悬浮颗粒在空气中的寿命较长，相关防护设备，尤其是呼吸防护设备，在牙科手术中至关重要。本研究获得的结果将为制定牙科手术指南中修订后的FT提供证据，并保护城市居民的健康和福祉。
