Background
The novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has precipitated the COVID-19 pandemic. The World Health Organisation (WHO)1 has recommended a society-wide quarantine approach (during acute or peak phases of the disease), social distancing and handwashing followed by contact tracing. Alongside this, most countries have suspended elective and non-urgent dental care,2,3 closing many practices with only emergency treatment provision.4,5,6 This acute phase of the pandemic is subsiding, although further acute phases are being seen in different countries. There is increasing dental need across populations and dental practices are suffering financially, so practices are opening and commencing care. However, the WHO has taken a cautious and risk assessment approach and recommended that situations where aerosol generating procedures (AGPs) are carried out should be reduced to a minimum, with additional precautions in place.
It is still controversial but there is growing concern over possible airborne transmission of SARS-CoV-2.4,5,6,7 Although there has been much written about possible spread of COVID-19 through aerosols generated in the dental surgery, reviews of the evidence show there is little directly relating to respiratory viruses, despite over 70 years of research into bio-aerosols in dental settings.8,9,10,11 Studies of microbial content of aerosols and splatter generated during dental procedures have mostly involved aerobic bacteria.9,10,11,12,13,14,15 Viral studies are sparse, focusing on blood-borne HIV and hepatitis B.8,16 This limits confidence in the assumptions around transmission of SARS-CoV-2 during dental treatment. Although there seems to be little supporting evidence for mass transmission of respiratory pathogens through provision of dental care in the past, evidence is still emerging around transmission of this novel virus, where there is no innate immunity in the global population.
In general, management of dental caries has traditionally involved using instruments that have potential to generate bio-aerosols containing saliva, blood and tooth debris; the high-speed air rotor,17,18,19,20,21 slow-speed handpiece22,23,24 and use of the air-water syringe to complete steps for most dental materials.16,17,25,26
Until uncertainty around the level of risk associated with SARS-CoV-2 transmission between dental staff and patients is resolved or an acceptable level of risk is agreed, and because many aspects of dental treatment generate aerosols, a precautionary position is to keep aerosol generation as low as possible.