Efficacy of personal protective equipment against coronavirus transmission

ABSTRACT Background This in vitro study evaluated the efficacy of personal protective equipment (PPE) and high-volume evacuation (HVE) against human coronavirus (HCoV) 229E spreading by a standard dental procedure. Methods Phantoms for both patient and operator were used to recreate a dental setting inside a custom-built class III cabinet-like chamber. The patient’s phantom mouth was inoculated with an HCoV-229E suspension having viral load similar to SARS-CoV-2 asymptomatic subjects. The dental procedure was performed using an air-turbine and HVE for 10 seconds. The efficacy of surgical masks, FFP2/N95 and FFP3 respirators, and face shields was tested using quantitative real-time PCR. Results The wide surface on which the inoculum was spread caused low contamination. Over the masks and respirators’ external surfaces when a face shield was not worn, viral loads ranged 1.2 to 1.4 log10 mean gene copies/cm2. When the shield was on, viral loads dropped below detection limit ( Conclusions All PPE combinations significantly reduced viral loads in the operator’s mouth below the detection limit, but HVE did not decrease viral contamination.