De-risking dentistry: Quantifying aerosols associated with routine dentistry to inform mitigation technology and operating practices

This project brings together internationally leading expertise in multiphase flows with key stakeholders working to develop evidence to underpin new protocols for safe delivery of UK dental care in the light of covid-19. Aerosol Generating Procedures (AGPs) are ubiquitous in dentistry due to mixed streams of air and water used as coolants during instrumentation. This coupled with evidence that oral fluids contain high levels of viral particles rapidly led to dental AGPs being identified as a critical transmission risk during the current pandemic and all routine UK dental care stopped. In this project, we will first characterise aerosols formed during the most common dental AGPs, (high-speed and low speed cutting of tooth substrate and ultrasonic dental scalers used for dental cleaning). High speed photography combined with appropriate illumination will be used for aerosol characterisation. The illumination angle and strength and image recording speed will be optimised for quantification of aerosol concentration and aerosol dispersion speed and distance from the source where the aerosol cloud can disperse. Then, measurements will be conducted in clinically relevant environments using training mannequins with ambient air exchange, enclosure size and operatory furniture reflective of different care settings. Following establishment of base-line aerosol behaviour for current care practices, mitigation steps, including modifications in air/water supplies to instrumentation, reduction in cutting speeds, high volume aspiration parameters and ambient air flow, will be explored. The direct involvement of clinical experts, virologists, public health policy researchers and instrument manufacturers will ensure that findings are rapidly considered.