Characterization and mitigation of aerosols and splatters from ultrasonic scalers

Ou, Q.; Placucci, R. G.; Danielson, J.; Anderson, G.; Olin, P.; Jardine, P.; Madden, J.; Yuan, Q.; Grafe, T. H.; Shao, S.; Hong, J.; Pui, D. Y. H.

Background: Dental procedures often produce aerosols and splatter which have the potential to transmit pathogens such as SARS-CoV-2. The existing literature is limited. Methods: Aerosols and splatter were generated from an ultrasonic scaling procedure on a dental mannequin and characterized by two optical imaging methods - digital inline holography (DIH) and laser sheet imaging (LSI). Capture efficiencies of various aerosol mitigation devices were evaluated and compared. Results: The ultrasonic scaling procedure generates a wide size range of aerosols up to a few hundred micrometers and occasional large splatter which emit at low velocity (mostly below 3 m/s). Use of a saliva ejector (SE) and high-volume evacuator (HVE) resulted in 63% and 88% of overall reduction respectively while an extraoral local extractor (ELE) resulted in a reduction of 96% at the nominal design flow setting. Conclusions: The study results showed that the use of ELE or HVE significantly reduced aerosol and splatter emission. The use of HVE generally requires an additional person to assist a hygienist, while an ELE can be operated hands-free when a dental hygienist is performing ultrasonic scaling and other operations. Practical Implications: An extraoral local extractor aids in the reduction of aerosols and splatters during ultrasonic scaling procedures, potentially reducing transmission of oral or respiratory pathogens, like SARS-CoV-2. Position and airflow of the device are important to effective aerosol mitigation.