Density of Airborne Bacterial Species in Dentistry Units in Urban Health Centers, Kermanshah, Iran

Background and Air pollution, especially in treatment centers is associated with several types of pathogenic microorganisms. In dental environment, dentists and patients are exposed to a great variety of infectious agents dispersed by aerosols and droplets produced during operative dentistry procedures. The aim of this study was to determine the density of airborne bacterial species in dental units in urban health centers in Kermanshah, Iran.
A total of 168 air samples was collected from 14 dental units via active sampling based on NIOSH 0800 standard. Relevant information, including the number of patients, temperature, relative humidity, space volume for each patient, type of dentistry service, and type of operational system were recorded. Density of total bacteria, Staphylococcus aureus, and Streptococcus pyogenes were determined as CFU/m3. Data was analyzed in SPSS® vs.16.0.
The mean density of total air bacteria was 338.54±120.43 CFU/m3 at the beginning of the day and 758.37 ±348.74 CFU/m3 during clinical activity. The mean values for density of Staphylococcus aureus and Streptococcus pyogenes increased after clinical activity. There were significant relationships between bacterial density with number of patients, space volume, and type of service.
The air bacterial density increased significantly during dental treatment in dentistry units. According to WHO standards, the air bacteriological quality of dentistry units studied were not acceptable during dentistry services, which leaves dentists and patients at risk of illnesses. Therefore, appropriate ventilation and using personal protective equipment are recommended.