Abstract:

Objective To determine two different interventions and understand pollution levels of aerosols and droplets in the air at different distances. Methods Used the air natural sedimentation to take sample of the aerosols and droplets, experimental group used the opening with aspirator function, control group used the strong negative pressure to attract intervention. Fall out samples were collected with nutritious agar plates placed in nine different spots, in front, left, right 50, 100, 150 cm from head height of the patient. Took the samples for four times, before cleaning teeth, 30 min and 60 min after the start, 10 min after cleaning teeth; took the samples of doctor’s mask and office table surface at the end, and appraisalled the number of colonies and species classification. Results There were significant differences between experimental and control groups, samples of which had bacterial colony counts, which were collected at 30, 60 min after cleaning teeth, 50, 100 cm in the same orientation. The difference was statistically significant（P<0.01）. There were significant differences between the experimental and control groups, samples of which had bacterial colony counts, which were collected at 30, 60 min after cleaning teeth, 150 cm in the same orientation. The difference was statistically significant（P<0.05）. Bacterial colonies of doctor’s masks and office countertops of experimental group were（1 493±35.73）,（1 538±71.85）CFU·m-3, significantly lower than the control group, bacterial colonies of which were（2 828±59.51）, （3 073±74.27）CFU·m-3. The found pathogenic microorganisms were identified as Stenotrophomonas maltophilia, Ochrobactrum anthropi, micrococcus and so on. Conclusion Aspirator openings can more effectively control the spread of aerosols and droplets.

Key words: dental clinic, aerosol, droplet, nosocomial infections