SARS-CoV-2 Did Not Spread Through Dental Clinics During the COVID-19 Pandemic in Japan

Background: Dental professionals were thought to have the most significant risk of coronavirus infection during the pandemic. Since the first Coronavirus Disease 2019 (COVID-19) patient was detected in Japan in January 2020, Japan has faced several waves of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections. However, no cluster of SARS-CoV-2 infections associated with dental procedures has been reported in Japan. In this study, we aimed to investigate the actual status of SARS-CoV-2 infection during the pandemic through antibody testing for dental professionals. We further investigated saliva and oral management-related aerosol to estimate the risk of virus transmission during dental procedures. Methods: SARS-CoV-2 antibody titer in the blood of dental professionals and their families was determined during the pre-vaccinated period of the SARS-CoV-2 wave to see the history of infection in Japan. Viral loads in saliva and in the aerosol generated during the oral management of COVID-19 patients were detected by RT-qPCR. Results: The antibody testing of dental healthcare providers during the early phases of the pandemic in Japan revealed low antibody positivity, which supported the low incidence of infection clusters among dental clinics. The aerosol generated during dental procedures may contain trace levels of SARS-CoV-2, indicating the risk of transmission through dental procedures is limited. Therefore, SARS-CoV-2 did not spread through dental clinics. Conclusions: Very few SARS-CoV-2 infections were observed in dental professionals who took appropriate infection control measures in the early period of the pandemic. Performing dental procedures using standard precautions seems to be sufficient to prevent SARS-CoV-2 infections.