From the MLMIC website:
Aerosols are a known transmission route of the COVID virus. In fact, just one milliliter of saliva from a COVID-19-infected person contains 120 million copies of the virus, each of which can cause infection. Dentistry is considered to be a high-risk profession during COVID-19 because of the dental staffs’ inherent close contact with patients’ mouths and saliva.
Researchers at Imperial College London and King’s College London studied aerosol generation in dental practices to find better alternatives, the results of which were published in a paper in the Journal of Dental Research. The researchers measured aerosols using cameras and lasers during procedures such as decay removal, applying and polishing finishes and adjusting prostheses.
The researchers recommend two adjustments to dental handpieces to make a big difference to aerosol production.
- Using just water coolants in the drills, rather than a mixture of water and air, limits the saliva that enters the air.
- Using drills at lower speeds also creates less disruption of saliva particles that then become aerosolized.
The researchers found that, together, those changes allow a dentist to perform a procedure while producing 60 times fewer aerosol droplets.
The most common drill is an air turbine type which creates dense clouds of droplets that can quickly contaminate a room. When using a different type of drill, a high torque electric micromotor, at speeds of less than 100,000 rpm without air streams, 60 times fewer droplets were produced than with the air turbine drills. The researchers acknowledged that slower drills are less efficient and cannot be used all the time or in every procedure.
Other factors that affect the speed of aerosol generation and movement are the positioning of the patient, the ventilation system in the room and the size and shape of the room.
Earlier research by the American Dental Association found that, although dentistry is considered a high-risk profession, the actual incidence of COVID-19 infection among dentists was very low. By June 2020, only 1% of dentists had contracted the virus, likely due to the stringent safety measures and PPE standards in place.
Dentists are reminded to visit the New York State Dental Association website for up-to-date information on NYS Health Law alerts and more. MLMIC also encourages dental providers to monitor all COVID-19-related updates on our resources page and continue to consult our detailed blog post on safely managing practices during the pandemic.