Abstract
AbstractIn dentistry, fallow time is a period which allows for airborne pathogens to settle out of the air and mitigate the risk of airborne infection transmission to dental professionals and staff. The current recommendation is a one hour period.Aims and Objectives We aim to show that air purification devices are an undervalued adjunctive measure to mitigate the risk of airborne transmission of pathogens, and so reduce fallow time.Methods Using a computational fluid dynamics software, we created a virtual dental surgery, and simulated a ten-minute aerosol generating procedure. We then modelled air flow in the room with no ventilation, and then the same room with an air purifier at a throughput of 430m3 h-1, and subsequently the room with one open window providing 6 ACH and no purifier. The particles released were monitored and their behaviour and airborne time measured and collated.Results and conclusions The room with no ventilation had a total particle number at 600s of 4.5million, which required 8400s to reduce by 99%. With an open window providing 6 ACH, we obtained a value of 2500s for a 99% reduction in airborne particles, and a similar peak particle volume. Conversely, when using an air purifier throughout the procedure, the peak particle number was ten times lower than the peak number without ventilation, or with an open window, and after the particle injection 99% airborne particle reduction was achieved 60s. Our findings suggest that the use of an air purifier greatly reduces the total particle volume in the air during the aerosol generating procedure, and the fallow period needed. The values found with 6 ACH and an open window are corroborated in other literature. The use of air purification could greatly reduce the risk of infection transmission in a dental surgery.
Using Computational Fluid Dynamics to Evaluate the Role of Air Purification in Reducing Fallow Time in Dentistry
