Spatiotemporal distribution of aerosols generated by using powder jet handpieces in periodontal department

Abstract

This study performed an on-site measurement of the spatiotemporal distribution of aerosols, at the range of 0.3-10.0 μm, generated during the use of the powder jet handpieces in a periodontal department. The mass concentration and number of aerosols were monitored within 1.0 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 doctors’ mouth). Overall, the concentration of aerosols during the dental treatments, mostly more than 1000 μg/m³, is much higher than the allowed thresholds in the area within 1.0 m away from the patient's mouth, putting a high exposure risk to the dental doctors and other nearby persons. Vertically, the concentration of aerosols is mostly comparable among on the three measured heights. Horizontally, the concentration of aerosols shows a non-uniform distribution around the patient's mouth, especially for larger aerosols at the area closer to the mouth. This is an important characteristic of the dental spattering, which is due to the high momentum of the generated aerosols and randomness of their spattering direction. The results indicate that the present control measures, including particularly the suction system, are not effective to prevent the spattering of high-momentum aerosols generated by using dental instruments. The high risk of cross-infection in dental hospitals and clinics calls for the advancement of control measures.