Assessment of nosocomial bacterial contamination in dental unit waterlines: Impact of flushing.

Purpose: This study evaluated the extent of bacterial contamination in water from dental unit waterlines (DUWLs).

Methodology: Water samples were collected (before flushing, 1 min post-flushing, and 3 min post-flushing) from 24 clinics (Group A: no disinfection, Group B: citric acid disinfectant) of a Government Dental College. Bacterial counts, identification, antibiotic sensitivity tests, determination of endotoxin levels, and scanning electron microscopy (to confirm the presence of biofilm) were performed.