Ultrasonic scaling in COVID‐era dentistry: A quantitative assessment of aerosol spread during simulated and clinical ultrasonic scaling procedures

Abstract

Objective: Healthcare agencies recommend limited use of aerosol-generating procedures to mitigate disease (COVID-19) transmission. However, total dispersion patterns of aerosols, particularly respirable droplets, via dental ultrasonic units is unclear. The purpose of this study was to characterize and map total spatter, droplet and aerosol dispersion during ultrasonic scaling in simulated and clinical contexts.Methods: Ultrasonic scaling was performed on dental simulation units using methylene blue dye-stained water. All resultant stain profiles were photoanalysed to calculate droplet size and travel distance/direction. Airborne particle concentrations were also documented 0-1.2 m (0-4ft.) and 1.2-2.4 m (4-8ft.) from patients during in vivo ultrasonic scaling with a saliva ejector.Results: Stain profiles showed droplets between 25 and 50µm in diameter were most common, with smaller droplets closer to the mouth. In-vivo particle concentrations were uniformly low. The smallest (<1 µm, PM1) and largest (>10 µm, PM10+) particles were most common, especially within 1.2 m (4ft.) of the patient. Respirable particles (PM2.5) were uncommon. Conclusions:Tests showed the highest concentration of small droplets in zones nearest the patient. While uncommon, particles were detected up to 2.4 m (8ft.) away.Furthermore, observed particle sizes were consistent with those that can carry infectious agents. Efforts to mitigate the spread of inhalable aerosols should emphasize proximate regions nearest the procedure, including personal protective equipment and the use of evacuation devices.

Assessment of dental personal protective equipment (PPE) and the relationship between manual dexterity and dissemination of aerosol and splatter during the COVID-19 pandemic

“…Of course, this result does not fully represent the clinical situation, but according to the research of Alexandra et al., in 2021. 19 The study stated that the size range for influenza A (80–120 nm) largely encompasses that of SARS-CoV-2（70–110 nm）, suggesting that most droplets detected in their simulated and clinical situation were capable of transporting SARS-CoV-2. In the above article, 19 the simulated test is also used dyes (methylene blue dye) as a test method to see the size of the droplet.…”

“… 19 The study stated that the size range for influenza A (80–120 nm) largely encompasses that of SARS-CoV-2（70–110 nm）, suggesting that most droplets detected in their simulated and clinical situation were capable of transporting SARS-CoV-2. In the above article, 19 the simulated test is also used dyes (methylene blue dye) as a test method to see the size of the droplet. It was also mentioned that the droplets of ultrasonic scaling may contain pathogens.…”

COVID-19 Pandemic and Periodontal Practice: The Immunological, Clinical, and Economic Points of View

“…Brushing the teeth and cleaning the tongue at least twice a day and oral rinsing with antiseptic solutions (like hydrogen peroxide 0.5-1.5%, cetylpyridinium chloride 0.1-1.5% or povidone iodine 0.23-1% [ 85 ], 1.5% hydrogen peroxide, mixture of cetylpyridinium chloride, and povidone iodine) all effectively reduce oral bacterial load [ 86 – 88 ]. Studies have shown that these products effectively inactivate SARS, MERS, and H1N1 in 1 minute [ 87 – 90 ]. Finally, oral hygiene should be well improved, especially in ICU and the patients over 70, if anyone seeks to reduce risk of aspiration pneumonia and COVID complications [ 66 ].…”

“…The droplets made after ultrasonic scaling are able to travel long distances. Therefore, as the sensitivity of SARS-CoV-2 dictates, any related surface must be very well disinfected in compliance with the usual protocol for surface disinfection and sterilization of devices [ 87 ].…”

Particle Size, Mass Concentration, and Microbiota in Dental Aerosols

“…The spread of particles is well established in dental literature. Pierre-Bez et al (2021) reported that at 0 to 1.2 m from the patient’s head, there is an increase in mass concentrations of particles compared to 1.2 to 2.4 m, indicating that these larger particles can settle and contaminate surfaces adjacent to the emission source. The same study found a significantly higher mass concentration of PM 1 compared to all other studied PM fractions at these distances ( Pierre-Bez et al 2021 ).…”