A preliminary experimental study on the user behaviors and aerosol emissions of electric toothbrushes

¹ School of Mechanical Engineering, Tongji University, People’s Republic of China
² Key Laboratory of Engineering Structure Performance Evolution and Control, Ministry of Education, Tongji University, People’s Republic of China

^* Corresponding author: weiye@tongji.edu.cn

Abstract

The oral cavity is a human organ where a high concentration of microorganisms occupies. Evidence has shown that using dental instruments may trigger the release of microbial aerosol indoors. In this paper, the aerosol emissions during the working process of electric toothbrushes were investigated as follows. First, brushing habits, e.g., the favorite brand and flavor of the toothpaste, first tooth/teeth to brush, etc., were determined by 70 questionnaires from university students. Second, typical toothpaste usage per time was determined as 0.3g–0.5g based on a squeezing test by the group. Third, an experimental setup was designed to simulate toothbrushing to measure aerosol emissions. Finally, the measured emissions during toothbrushing were compared with other oral activities. The results showed that the peak PM_2.5 emission rate can reach up to 5.9 μg/s by using a typical toothpaste dosage. The number of particles emitted if the incisors were brushed first can be 1–2 times higher than if the molars were firstly brushed. The magnitude of aerosol generated from electric toothbrushing was similar to that of coughing and sneezing.