Aerosol mitigation efficiency of high-volume suction systems during aerosol-generating dental procedures with...

Routine dental procedures can expose dental providers to aerosols associated with potential acute or chronic respiratory health effects. High-volume suction (HVS) systems can potentially mitigate aerosols generated during routine dental procedures; however, few studies to date have evaluated HVS systems' aerosol exposure mitigation efficiency during procedures with patients. This study reports the aerosol mitigation efficiency of 5 commercially available HVS systems [standard high-volume evacuation (HVE), 3 intraoral HVS systems (Systems A-C), and 1 modified HVE (System D)] when used during dental procedures utilizing a high-speed handpiece (ie crown preparations) or ultrasonic scaler. Direct-reading instruments measured aerosol size distribution, aerosol number concentrations (thoracic [PM10]), and aerosol mass concentrations (respirable [PM4] and thoracic [PM10]) while using each of the 5 HVS systems during high-speed handpiece (n = 26) or ultrasonic scaling procedures (n = 25). Background and procedure aerosol measurements were collected in the (i) operatory near the dentist and (ii) hallway outside the operatory. Factors including (i) HVS flow rate, (ii) procedure duration, (iii) crown preparation tooth location, and (iv) ultrasonic scaler type and mouth quadrant(s) treated were recorded. Ratios of procedure-to-background aerosol concentrations were calculated, and multiple linear regression models were fit accounting for covariates to determine if an HVS system reduced mean aerosol number concentrations to levels no different from background concentrations (ratio 95% lower confidence limit ≤1). The percentage frequency of how often PM4 or PM10 mass measurements were reduced to concentrations below average background concentrations was also calculated for each HVS system. Standard HVE, System A, and System D reduced aerosol number concentrations to background concentrations during both procedure types. Additionally, standard HVE reduced aerosol mass concentrations to background most often during either procedure type. However, none of the 5 HVS systems fully reduced aerosol mass to background levels during high-speed handpiece procedures, despite all HVS flow rates being greater than a flow rate previously reported as sufficient for aerosol capture during high-speed handpiece procedures. Further, the effect of HVS flow rate on PM10 number ratios during either procedure type varied across HVS systems. Future studies are needed to identify factors that can improve HVS systems' aerosol mitigation efficiency, including HVS flow rate ranges needed to sufficiently mitigate aerosol exposures during common patient procedures.