Potential Modes of Transmission for SARS-CoV-2 in the Dental Office

Evidence suggests that SARS-CoV-2 can be transmitted both directly from person-to-person by respiratory droplets and via indirect fomite-mediated transmission.^4,5 Viral shedding by asymptomatic individuals has been reported during an asymptomatic prodromal period of up to 14 days with the potential for viral shedding up to 24 days.⁷² Live SARS-CoV-2 viruses have been isolated from saliva of infected individuals and the concentration of virus in saliva has been shown in some cases to be significantly higher than that on nasopharyngeal testing swabs.^13,73 Not surprisingly, ACE2⁺ cells are abundant throughout the respiratory tract and salivary gland duct epithelium.^25,65 In the SARS epidemic in the early 2000s caused by SARS-CoV-1, epithelial cells of the salivary gland ducts were early targets for viral infection.⁷⁴

Transmission of SARS-CoV-2 is increased in the dental setting due to the close interpersonal contact between individuals involved and by nature of the procedures performed during the delivery of dental care.^75-77 Both DHCPs and patients are at risk due to droplets containing microorganisms or direct contact with conjunctival, nasal, or oral mucosal tissues.^{17-20,30,75-78} Furthermore, SARS-CoV-2 may survive between 4 to 72 hours on hard surfaces, which can lead to indirect exposure after touching such surfaces."⁷⁰ The likelihood of such transmissions may be dependent upon the viral load of the infected individual and the susceptibility of the host individual.⁷⁹ Potential pathways of SARS-CoV-2 transmission in the dental office are outlined in Figure 2.

Figure 2. Potential transmission pathways for SARS-CoV-2 in the dental office.²⁵

Figure 2. Potential transmission pathways for SARS-CoV-2 in the dental office.²⁵