A questionnaire-based survey of COVID-19 transmission in dental practice during the pandemic:comparison between the 1st-5th and the 6th-8th surges in Japan

Background: Previously, we conducted a questionnaire survey on infection control measures and infection status among practicing dentists in Nagano prefecture, Japan, between February 2020 and September 2021 (1-5 ^th surge of COVID-19 cases in Japan) and found that the risk of COVID-19 infection spreading through dental care was very low. However, it was noted that the low number of infected patients during the survey period may have been a contributing factor. Subsequently, an explosive increase in the number of infected patients was observed, raising the possibility of nosocomial infections in dental treatment settings. Therefore, in this study, we reexamined the infection situation in dental care settings at the time of infection spread and compared the results with those of previous reports. Materials and methods An online questionnaire-based survey on clinical activities, infection control measures, and confirmed or probable COVID-19 cases among patients and clinical staff were conducted between February 2022 to March 2023 (6-8 ^th surge). Results The number of COVID-19 positive patients increased approximately 50-fold between the study periods. There was a 3.5-fold increase in the rate of treatment for infected patients. Even with the increased likelihood of contact with COVID-19 patients, no cases of infection during dental treatment were observed. Conclusions The results of this study indicate that even with the possibility of contact with COVID-19 during dental treatment, the likelihood of COVID-19 clusters occurring in dental practices is low if appropriate infection prevention measures are in place.