Microbiological and Ergonomic Effects of Three Prototypes of a Device to Reduce Aerosol Dispersion in Dental Care During the COVID-19 Pandemic: A Randomized Controlled Clinical Trial

Objectives: This randomized clinical trial evaluated the microbiological efficacy and the ergonomic impact of three prototypes of a device to reduce aerosol dispersion during dental procedures. Methods: Sixty patients undergoing dental care using high-speed turbines and/or ultrasonic tips were randomly assigned to 4 groups (n = 15): CG: control group, with standard personal protective equipment (PPE); G1: PPE + acrylic device (AD) with aspiration; G2: PPE + AD without aspiration; and G3: PPE + polyvinyl chloride device. The device prototypes consisted of a rigid translucent acrylic structure (G1 and G2), or a rigid PVC tube structure surrounded by layers of translucent flexible PVC films (G3), adjusted to the dental chair, involving the patient's head, neck and chest. The main outcome was the microbiological analysis (mean Delta of CFU at 10 different sites), and the secondary outcome was the ergonomic evaluation (questionnaire to dentists and patients). Results: The final sample comprised 59 participants (mean age 38.6 +/- 11.4 years, 55.2% male). The overall mean time for dental procedures was 32.4 +/- 16.9 min, with no differences between groups (p = 0.348). Microbiological analyses showed that the use of the device significantly reduced contamination in the light reflector (01.46 +/- 4.43 Delta CFU in G2 vs. 19.25 +/- 36.50 Delta CFU in CG; p = 0.028), apron (09.11 +/- 12.05 Delta CFU in G3 vs. 21.14 +/- 43.41 Delta CFU in GC; p = 0.044), and face shield (08.80 +/- 32.70 Delta CFU in G1 vs. 56.78 +/- 76.64 Delta CFU in the GC; p = 0.017). The device was well accepted by patients and increased the dentists' perception of safety and protection (p < 0.001), but significantly decreased ergonomics related to the clinical view, space, agility and access to the patient, and ease of performing procedures (p < 0.001). Conclusions: The tested device can be an additional tool for infection prevention and control in dentistry, not only during the COVID-19 pandemic, but also for the control of future infectious diseases and epidemics.