RESUMO
The purpoe of this study was to investigate contamination of the dental unit water systems in a sample of dental clinics in Saudi Arabia. A total of 270 water samples [200mL/sample] was collected from the handpieces line, air-water spray and tap water sources of the dental clinics. Microorganisms were identified using established culturing techniques [Analytab Products Inc.] The prevalence of bacterial contamination was 84% in dental unit water lines of handpieces and 64% in air-water spray, while it was 10% in tap water samples. Bacillus and Pseuodmonas were found to be the predominant [52%] pathogenic microorganisms. The results indicated that dental unit water systems tested were contaminated. Therefore, more effort should be directed to reduce [if not totally eliminate] the number of pathogens in the dental unit water systems