Prevalence of E. coli and Coliform bacteria in the Dental Unit Waterlines of Private Clinics of Islamabad and Rawalpindi

Abstract

Bacteria colonizing surfaces and forming biofilm in dental unit waterlines is a well-documented phenomenon. Pathogenic bacteria from contaminated dental unit water lines are transmitted with aerosols and splatter generated during dental procedures. Objective: To identify the presence of coliform bacteria and E. Coli in dental unit waterlines of private dental clinics in Islamabad and Rawalpindi to see whether they meet the criteria for drinking water. Methods: This is a quantitative study carried out on 30 active dental units. Triple syringe and handpiece outlet water samples were taken. Samples were evaluated by National Institute of Health (NIH) through Polymerase Chain Reaction (PCR). The cultures were incubated twice at 24 and 48 hours. The presence of coliform bacteria and E. coli in the samples was evaluated. Results: Approximately 20% of the samples were found to have coliform bacteria and E. coli. Some private dental clinics in Islamabad and Rawalpindi use dental unit waterlines that do not meet the criteria for drinking water. Conclusions: Dental unit water lines (DUWLs) must meet the set criteria for drinking water to reduce the risk of infections. Contamination with coliform bacteria and E. Coli were evident in some of the dental clinics. This contamination can be reduced by following Center for Disease Control (CDC) guidelines and using chemical treatment protocols for cleaning dental unit waterlines.