Background: Bio films form speedily on dental unit waterlines. The specific design of dental units favors bacteria to colonize surfaces and to form biofilm in water supply tubes, together with dental unit water line (DUWL). In recent years, microbial contamination of DUWLs has become a prominent infection control issue even receiving some alarmist coverage in the media. More than 25 different species of bacteria have been isolated from DUWLs. It may also harbour opportunistic pathogens that are responsible for respiratory disease – namely P. aeruginosa, Legionella spp and non–tuberculous Mycobacterium spp. Aim: To determine the predominant bacteria isolated from DUWL biofilm attached to ultrasonic scaler device. Method: A total 10 sample were collected from department of period ontology, TKDC & RC, Kolhapur. Each tube was aseptically cut into 2 cms length. The biofilm was removed by scraping the wall with a scalpel and the scraping were suspended in peptone water. Each suspension were spread on agar plate and incubated for 48 hrs. To obtain pure culture, morphologically different colony forming unit (CFU) were selected for subculture. Finding: The following aerobic organisms were found in samples of DUWL. Proteus species, Bacillus species, Staphylococcus albus, Staphylococcus citreus, Staphylococcus aureus. Conclusion: From the DUWL, the microorganism are transmitted with aerosol and splatter, generated by working unit handpieces. Numerous studies highlight the need for effective mechanisms to diminish the microbial contamination in DUWL and emphasize the threat for cross-infection in general practice, especially in view of the ever-increasing number of persons with immunocompromised state who present at outpatient dental clinics.
