Microbiological evaluation of dental unit water systems in teaching hospitals in Karachi Pakistan

Objectives: The microbial quality of water in dental unit water system (DUWS) is of considerable importance because patients and dental staff are regularly exposed to water and aerosol generated from the dental units. The objective of this study is to evaluate the DUWS in teaching hospitals and to determine the total viable count and the different species of micro-organisms present.
Methods: Water samples were taken from ten different dental units from each of the four dental teaching institutes. The samples were collected from the distal outlet of the 3-in-1 syringe. Analysis was done using spss version 16
Results: The mean TVC value for all the water samples was 2.843 log CFU/ml. multiple colonies of micro-organisms were isolated including Klebsiella pneumoniae and the opputunistic pathogens such as Legionellae
Conclusions: The study emphasizes the need for effective mechanisms to reduce the microbial burden within DUWS and highlights the risk of occupational exposure and cross infection in dental practice.