Risk for dental healthcare professionals during the COVID-19 global pandemic: An evidence-based assessment

OBJECTIVES: Heightened anxiety among dental healthcare professionals (DHPs) during the COVID-19 pandemic stems from uncertainties about the effectiveness of personal protective equipment (PPE) against dental aerosols and risk levels of asymptomatic patients. Our objective was to assess the risks for DHPs providing dental care during the pandemic based on available scientific evidence. METHODS: We reviewed the best available evidence and estimated the annualized risk (p=d(a)s(1−1-p(0)p(1)(1-e)(y)(n)) for a DHP during the COVID-19 pandemic based on the following basic parameters: p(0), the prevalence of asymptomatic patients in the local population; p(1), the probability that a DHP gets infected by an asymptomatic patient; e, the effectiveness of the PPE; s, the probability of becoming symptomatic after getting infected from asymptomatic patient; d(a), the probability of dying from the disease in age group a; n, number of patients seen per day; and y, number of days worked per year. RESULTS: With the assumption that DHPs work fulltime and wear a N95 mask, the annualized probability for a DHP to acquire COVID-19 infection in a dental office, become symptomatic, and die from the infection is estimated at 1:13,000 (0.008 %) in a medium sized city in the US at the peak of the pandemic. The risk estimate is highly age-dependent. Risk to DHPs under the age of 70 is negligible when prevalence of asymptomatic cases is low in the local community. CONCLUSIONS: Risk of COVID-19 transmission in dental office is very low based on available evidence on effectiveness of PPE and prevalence of asymptomatic patients. Face shields and pre-procedure oral rinses may further reduce the risks. CLINICAL SIGNIFICANCE: DHPs should follow guidelines on pre-appointment protocols and on PPE use during dental treatments to keep the risk low.