A dental unit waterline is a perfect environment for microbial growth and biofilm formation, due to their dimensions, material, low flow and minimal use of water. Incoming water can introduce different water bacteria including Legionella and Pseudomonas to the DUWLs, where they can proliferate to high numbers and can be spread through the handpieces to the patient or staff and can cause mild to severe illness.
Guidelines for water quality of dental unit systems
The general international agreement on the quality of water from dental units is that water quality of dental unit systems should meet the demands for drinking water standards.
Guidelines for water quality in dental unit systems:
|Heterotrophic bacteria (total viable count)||500 CFU/ml||CDC, APHA, most national guidelines|
|Legionella species||100 CFU/l||CDC, APHA, most national guidelines|
Ensure safety for patients and staff
The guidelines for dental unit water recommend testing the water at least once a year, however the water quality can change many times during a year. To some dental clinics the yearly water control water can result in closing down the dental unit due to elevated bacterial levels.
By monitoring the water quality more often, the situation can be controlled in time and ensure that the safety level is high at all times.