Dental high-speed handpiece and ultrasonic scaler aerosol generation levels and the effect of suction and air supply

• Published in: Infection control and hospital epidemiology 2023-06, Vol.44 (6), p.926-933
• Main Authors: Choi, Joanne Jung Eun, Chen, Jason, Choi, Yunsun Jane, Moffat, Susan M., Duncan, Warwick J., Waddell, J. Neil, Jermy, Mark
• Format: Article
• Language: English
• Subjects: Aerosols; Coronaviruses; COVID-19; Design; Disease transmission; Evacuation; Health risks; Humans; Masks; Oral hygiene; Original; Original Article; Ozone; Pandemics; Particle counters; Pathogens; Personal protective equipment; Suctioning; Teeth; Ultrasonic Therapy; Ultrasonics; Ventilation
• ISSN: 0899-823X; 1559-6834
• DOI: 10.1017/ice.2022.196

Exposure to aerosol spray generated by high-speed handpieces (HSHs) and ultrasonic scalers poses a significant health risk to oral health practitioners from airborne pathogens. Aerosol generation varies with different HSH designs, but to date, no study has measured this. We measured and compared aerosol generation by (1) dental HSHs with 3 different coolant port designs and (2) ultrasonic scalers with no suction, low-volume evacuation (LVE) or high-volume evacuation (HVE). Measurements used a particle counter placed near the operator's face in a single-chair, mechanically ventilated dental surgery. Volume concentrations of aerosol, totaled across a 0.3-25-µm size range, were compared for each test condition. HSH drilling and scaling produced significantly high aerosol levels ( < .001) with total volume concentrations 4.73×10 µm /m and 4.18×10 µm /m , respectively. For scaling, mean volume of aerosol was highest with no suction followed by LVE and HVE ( < .001). We detected a negative correlation with both LVE and HVE, indicating that scaling with suction improved operator safety. For drilling, simulated cavity preparation with a 1-port HSH generated the most aerosol ( < .01), followed by a 4-port HSH. Independent of the number of cooling ports, lack of suction caused higher aerosol volume (1.98×10 µm /m ) whereas HVE significantly reduced volume to -4.47×10 µm /m . High concentrations of dental aerosol found during HSH cavity preparation or ultrasonic scaling present a risk of infection, confirming the advice to use respiratory PPE. HVE and LVE both effectively reduced aerosol generation during scaling, whereas the new aerosol-reducing 'no air' function was highly effective and can be recommended for HSH drilling.