Aerosol suppression from a handpiece using viscoelastic solution in confined dental office

Abstract

Aerosolized droplets are produced en masse in dental practices; these aerosols disperse in the surrounding space, posing a health threat if the patient is infected with a transmittable disease, particularly COVID-19. Here, a viscoelastic polyacrylic acid (PAA) solution was used to minimize liquid aerosolization and limit the travel distance of aerosols. The PAA concentration was varied to evaluate its effect on aerosolization and droplet size resulting from procedures using dental handpieces, which include tooth cutting, grinding, and polishing. In addition, a thermocouple was inserted at the center of the model tooth to measure its temperature during a handpiece operation. The temperature data suggest that the cooling performance of the PAA solution is comparable to that of pure water in operations in the occlusal and facial directions. The PAA solution droplets splattered on the patient's facial area during the handpiece operation are markedly larger than those of pure water, which is evidence of the settling of the PAA droplets, preventing further transmission. Accordingly, the travel distance of the aerosolized PAA droplets was limited by viscoelastic resistance to droplet detachment. This comparison of the aerosol suppression capability between water and PAA solutions confirms the benefit of using viscoelastic solutions for various dental operations.