Evaluating Salivary Aerosol Spread and Contamination Risks During Dental Procedures in an open-plan clinic

Saliva has been regarded as a potential transmission medium in dentistry. This study aims to investigate the dispersion of salivary aerosols on susceptible individuals and assess the resultant environmental contamination, focusing on field measurement during drilling procedures. To visualize salivary dispersion during dental procedures, a fluorescein solution was introduced into a dental manikin's mouth. Spectrofluorometry quantified the spatial-temporal distribution of salivary aerosols in the breathing zones of both the operator and the patient in the adjacent bay, along with environmental contamination. Aerosol particles from 0.5 to 20 μm in diameter were measured by an Aerosol Particle Sizer (APS). Fluorescence photography was used to evaluate the contamination on the operator's dominant hand. Employing High-volume evacuators (HVE) reduced fluorescence by 52% and peak concentration by 65%. Particle size distribution showed a substantial proportion of <1 μm particle number concentrations with a notable increase in fine particles during the operation. There was no significant difference in the contamination of the dominant hand regardless of whether the HVE was used or not (P=0.839>0.05). Remarkably, the fingertips exhibited notable contamination (inner surface 0.11%, outer surface 0.13%). The results highlighted the potential transmission risk of patients’ salivary to dental staff, emphasizing vital coordination between the HVE and dental instruments.