A clinical observational analysis of aerosol emissions from dental procedures.

There remains uncertainty as to which dental procedures constitute aerosol generating procedures. We aimed to quantify aerosol concentration produced during different dental procedures. Where aerosol was detected, we assessed whether the aerosol size distribution from patient procedures was explained by the non-salivary contaminated instrument source, using phantom head controls. This study obtained ethical approval within the AERATOR grant. Patients were recruited consecutively, and written consent was obtained. Both an optical and an aerodynamic particle sizer were used to measure aerosol, attached to a 3D-printed polylactide funnel 22cm from the patients face. A range of periodontal, oral surgery and orthodontic procedures were captured using time-stamped protocols. High-fidelity phantom head control experiments for each procedure were performed, under the same conditions. Aerosol was measured for each procedure. Where aerosol was detected, phantom head control and patient procedure aerosol size distributions were compared, with the assumption that if the distributions were the same, aerosol detected from the patient could be explained by the instrument source. 41 patients underwent fifteen different dental procedures. For nine procedures, no aerosol was detected. Where aerosol was detected, the percentage of procedure time that aerosol was observed above background ranged from 12.7% for ultrasonic scaling to 42.9% for 3-in-1 air + water syringe. For ultrasonic scaling, 3-in-1 syringe use and surgical drilling, the aerosol size distribution matched the non-salivary contaminated instrument source. High and slow speed drilling produced aerosol from patient procedures which appear to have different size distributions from a phantom head control and so may pose a greater risk of (potentially infected) salivary contamination. Ultrasonic scaling does not appear to generate additional aerosol above that of the instrument itself and therefore does not increase the risk to dental teams, relative to the risk from being in close proximity to the patient.