Microbial diversity in dental unit waterlines.

Dental health care providers and patients are exposed during ongoing work to contamination by the water used in the dental units, due to accidental swallowing or aspiration of the sprays generated by the high-speed handpiece and the threeway syringe. This study evaluated the quality of water in dental units in the public dental care system of Maceio, Alagoas, Brazil, by conducting analyses of contamination by total coliforms, E.Coli, heterotrophic bacteria and filamentous fungi. We collected 200 mL of water at 5 sites in 6 dental offices of the Department of Health located in different parts of the city. A total 212 isolates and 16 genera of filamentous fungi were identified in the water collected from the dental units. Total coliforms indicated that the water used in dental units was not appropriate for human consumption. The high levels of contamination found in this study showed that water was a potential source of cross-infection.