Study uses LED imaging to visualise aerosols generated during dental treatment

Not only saliva but also materials such as silicon, calcium, potassium and zinc can produce aerosols, which, if inhaled, can lead to respiratory issues. The researchers believe that understanding the spread and diffusion of such particles in the air can help protect individuals from potentially harmful substances and diseases that can be spread through airborne droplets.

Using a dental air turbine and a mannequin, researchers at Tohoku University in Sendai recreated the droplets and aerosols that occur during dental procedures. They used a high-sensitivity camera and high-intensity LED light source to create high-quality images of the droplet spreading during the simulated procedure and assessed the efficacy of extra-oral suction (EOS) and intra-oral suction (IOS). They found that the devices reduced droplet and aerosol spread in the air by 97.8% when both EOS and IOS were used and by 92.1% when only IOS was used.

“Since the droplets and aerosols (“spray” and “mist”) generated during dental treatment contain bacteria and viruses derived from saliva and blood, elucidation of their spreading and diffusion dynamics is required from the perspective of COVID-19 prevention,” said lead author Jun Watanabe, a researcher at the university.

The researchers also noted that the spread of the droplets changed, depending on the treatment and bur type. They found that cavity treatments on the anterior teeth were the most likely to be associated with droplet spreading and that a bud-shaped bur on the air turbine generated the most aerosols compared with round-shaped, round end-tapered or needle-tapered burs.

Additionally, they pointed out that it is vital to place the oral suction device correctly. The most effective positioning of the EOS device was found to be approximately 10 cm away from the patient’s mouth at a 0º angle.

“Analysis in various clinical situations is expected to elucidate the dynamics of dental treatment-derived droplets and aerosols and lead to the establishment of new dental treatment protocols, the development of air purification equipment and the development of a cleaner and safer dental care environment,” said co-author Prof. Hiroyasu Kanetaka, a researcher at the Liaison Center for Innovative Dentistry at Tohoku University.

Further research using a patient model is required to validate the efficacy of oral suction devices.

The study, titled “Visualization of droplets and aerosols in simulated dental treatments to clarify the effectiveness of oral suction devices”, was published online on 22 February 2023 in the Journal of Prosthodontic Research, ahead of inclusion in an issue.