Detection of dental fomites using topical fluorescein. Br Dent J 2022; http://doi.org/10.1038/s41415-022-4403-7

COVID-19 can spread through surface contamination, aerosols and droplets, which renders thorough surface disinfection of paramount significance for a dental environment. However, droplets are transparent and often have microscopic size, which makes it difficult or impossible to detect in clinical practice without additional methods.

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Given that there was ambiguity around fallow time between patients and the difficulty to measure aerosols in clinical environments, the researchers used fluorescein dye to stain dental irrigants. They performed a series of aerosol generating procedures on a dental manikin under high-volume suction. Subsequently, they viewed droplets and fomite spread around the dental chair, with and without an ultraviolet (UV) light, and documented it with use of photography. This aimed to provide a better understanding of the spread of dental droplets.

Observations under normal light showed minimal or no droplet spread around the manikin, but were visible on face and teeth. However, UV light use allowed detection of fluorescein on the operator, chairs, handpieces, splatter on the floor and on the instrument tray, which was surprising and educational for the staff members.

In conclusion, the COVID-19 pandemic instigated the generation of a large amount of research on aerosols in dental practice. Apart from good ventilation, it is also important to identify surface contamination with droplets as a potential way of spread. Fluorescein facilitates the detection of droplet spread and helps clinical staff to see high-risk areas that require thorough cleaning. Clinical-grade fluorescein is cheap and readily available, which means that this model could easily be used in clinical practice to determine spread within individual clinics and could be used to train the dental team, highlighting areas which require cleaning between patients and can be easily missed with fluid contamination without use of fluorescein.