Qualitative and quantitative analysis of bacterial aerosols.

The objective of this study was to investigate qualitatively and quantitatively the bacterial aerosols before, during, and after clinical work sessions in different areas within a multichair dental clinic, an isolation clinic, the sterilization center, and the prosthetic laboratory in the College of Dentistry, King Saud University. Also, the contributions of aerosols generated by different types of dental procedures were investigated. Air sampling using blood and heart infusion agar plates at four selected areas was performed three times per day over a 2-week period before, during, and after clinical sessions. The concentration of total bacterial aerosols was 5 times higher in the multichair clinic, 3.6 times higher in the prosthetic laboratory, 2 times higher in the sterilization center and isolation clinic during working sessions as compared to before the working sessions. At the end of the working day, aerosols decreased 50-70% in all areas. Staphylococcus epidermidis had the highest prevalence (37.12q%) of colony composition of bacteria examined. This study demonstrates that aerosols increase during and after work sessions and, therefore, increase the chance for infectious agent transmission. Preventive measures should be instituted to reduce or disrupt aerosols as a transmission route in the multichair dental clinic, sterilization center, prosthetic laboratory, and isolation clinic.