Aerosol Capture Efficiency of a Prototype Dental Aerosol Shield

Details

• Personal Author:
  Onuche E
• Description:
  Aerosols and splatter generated during dental procedures have the potential to transmit infectious diseases to patients and dental personnel. This study evaluated the performance of the newly developed aerosol evacuation device named as Pro-TecT-Shield (PTS). The objective of this study was to evaluate PTS aerosol capture efficiency at distinct flow rates for various particle sizes, and the impact of aerosol plume velocity on PTS performance as well as the effects of PTS placement relative to aerosol plume. This study was performed in 2 phases. Phase 1 involved suction airflow determination for high-volume extractors (HVE) installed at the Miranda Clinic of the University of Oklahoma Health Sciences Center College of Dentistry (OUCOD) and plume velocities that are typically generated during the delivery of routine dental care. This phase revealed that HVE flowrates ranged from approximately 104 to 194 liters per minute (Lpm), and plume velocities varied from approximately 3 to 62 feet per minute (Ft/min) as measure while simulating dental procedures (cavity preparation or dental plaque removal using a high-speed turbine and an ultra-sound, respectively; note that air/water spray was used in both simulations). In Phase 2, PTS capture efficiency was determined resolved by the diameter of particles (diameters from 0.3 µm to 5 µm). Other influencing factors such as HVE flowrates (100 and 200 Lpm), aerosol plume velocities (6, 25, 50 and 100 Ft/min) and PTS spatial positioning were also investigated as they are known to influence the efficacy of aerosol mitigation devices, such as the PTS. A NaCl solution (at 2%) was used together with a Collison Nebulizer (3 Jet, CH Technologies, Westwood NJ, USA) to generate the test aerosols. A laser aerosol spectrometer (TechnIK GmbH & Co. KG, Model 1.108) was used to determine PTS capture efficacy for particles with varied diameters (< 0.3 µm up to 20 µm). Data reduction and analysis was performed in Jupyter Notebook Software (version 6.3.0) with a Python code developed by Dr. Changjie Cai using mixed effect regression model. Findings from this study have demonstrated that the PTS was significantly (p = 0.003) more effective exhausting particles of small diameters (0.3 µm-5 µm) when operated at 200 Lpm flowrate as compared to 100 Lpm. Collection efficiency was observed to vary as a function of plume location on the PTS. At both HVE flowrates, overall collection efficiency decreased with the increase in distance from the vacuum manifold. At HVE flowrate of 200 Lpm, and all plume velocities (6, 25, 50 and 100 Ft/min), average collection efficiency ranged from 70%-100% at plume locations closest to PTS suction manifold. As such, the PTS should be positioned to intercept the aerosol plume as close to the suction manifold as practicable during the delivery of routine dental care. The use of PTS in this manner will minimize the risk of infectious disease transmission in dental settings. [Description provided by NIOSH]
• Subjects:
  Aerosols Communicable Diseases Dental Offices Occupational Health Safety
• Keywords:
  Aerosol Particles Control Equipment Dentistry Face Shields Infectious Diseases Particle Aerodynamics
• Publisher:
  University of Oklahoma Health Sciences Center
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Thesis
• Place as Subject:
  Oklahoma ; OSHA Region 6
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-62
• NIOSHTIC Number:
  nn:20068913
• Citation:
  Oklahoma City, OK: University of Oklahoma Health Sciences Center, 2021 Dec; :1-62
• Federal Fiscal Year:
  2022
• Performing Organization:
  University of Oklahoma Health Sciences Center
• Peer Reviewed:
  False
• Start Date:
  20050701
• End Date:
  20290630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:2233b82b316d411c5558708f8a4232035981945a27a4704f7dfeb8a5a658d42ca7462e230a436b0e2a3d85ad3a841fa01dae2ce86e6273c386acc5caa5b31799
• Download URL:
  https://stacks.cdc.gov/view/cdc/207476/cdc_207476_DS1.pdf
• File Type:
  [PDF - 2.01 MB ]