Dental unit waterline safety: The science and what dental professionals need to know

The science of waterlines and what dental professionals need to know

In many areas of dentistry, outcomes are determined by the dental health-care professional’s (DHCP) level of ethics, standard of care, and ability to stay up to date. Dentistry is not static; being aware of current findings and embracing them ethically can protect both the patient and DHCP from disease. Dental unit waterlines are one of these areas. When new findings and regulations come forward, finding out if you are in compliance can be daunting—like opening a can of worms. Finding out you have an issue and addressing it can be a defining moment.

What do we know?

Recently, there has been a focus on water safety in dentistry. Dental unit waterline systems (DUWS) have long been known as a harbor for high concentrations of potentially pathogenic bacteria.1 The small tubing has proven a haven for specific pathogenic bacteria,2 including Pseudomonas spp., Legionella spp., and nontuberculosis mycobacteria.3 Most microorganisms detected in DUWS come from public water supply and do not pose a risk for healthy patients. Until recently, it was assumed infection was possible only in immunocompromised patients. But infection outbreaks involving at least 90 healthy patients in Anaheim, California, and Atlanta, Georgia, suggest otherwise. There are now documented cases of direct transmission of disease from DUWS.4–10


Recent cases of disease acquisition from dental waterlines involving healthy children have also brought the topic to the forefront in dentistry and the media.11,12 DHCPs may also be put at risk by exposure to water spray and aerosols from devices that use DUWS.