Patients Trust Your Waterlines Are Safe, Should They?

Are your dental unit water lines (DUWLs) as clean as your professional reputation? Patients trust you with their health—don’t let poor waterline maintenance put that at risk.

By Genni Burkhart, Editor

A constant challenge in infection control, dental unit water lines (DUWLs) can be a breeding ground for dangerous microorganisms that thrive in biofilm. If there's moisture, there's the possibility of microbial biofilm, which collects on surfaces and disperses into the air. Unfortunately, biofilm is a persistent foe for dental practices, thriving in waterline tubing supplied by city water or private wells that are far from sterile.

While the Centers for Disease Control (CDC) and the American Dental Association (ADA) have long advocated for federal mandates regarding DUWLs, none currently exist. However, states such as California,¹ Washington,²and most recently, Georgia³ have additional requirements beyond CDC recommendations.⁴

Given the potential risks of waterline contamination infecting patients⁵ and exposure to legal liability, dental practices should establish robust DUWL protocols in addition to state guidelines or a lack thereof. These protocols should include regular monitoring, testing, and maintenance of safe waterlines as well as staff education on the importance of this issue.

Rare, Yet Serious Consequences

In 2022, the CDC issued a health advisory⁶ regarding waterborne Nontuberculous Mycobacteria⁷found in the waterlines of dental practices in California and Georgia. After 1,082 patients were put at risk, 71 patients, with an average age of 6 years old, were infected and required surgical intervention.

Previous outbreaks⁷ were confirmed in 2022, 2015, and 2016.⁸ In at least two of these outbreaks, public health investigators found the clinics were not using disinfectants on their dental units or regularly monitoring water quality.

While outbreaks are rare, the complications are devastating. Patients affected have endured tooth loss, hearing loss, facial nerve palsy, and incision fibrosis. Others have faced cervical lymphadenitis or mandibular and maxillary osteomyelitis, complications so severe they required surgical intervention and hospitalization.

Some patients as young as 4 years old have been left with lasting health issues, enduring consequences they will carry throughout their lives, all of which were preventable.

A Dirty Water Secret

Numerous lawsuits have been filed⁹ against dental practices for non-compliant waterlines. However, many cases are settled out of court with confidentiality clauses. Because these incidents often go unpublished, the public is left unaware of the potential risks. Unfortunately, this lack of accountability and transparency allows some dental practices to operate in noncompliance, treating patients with unchecked and unmonitored DUWLs.

A 2023 report from RDH Magazine¹⁰ revealed alarming statistics from a survey of dental professionals about waterline maintenance and safety. Ten percent of respondents reported doing nothing to treat their DUWLs, and even more concerning, 24 percent reported not testing waterlines at all.

In 2018, a whistleblower (dentist) in Richmond, VA, reported to a local CBS news station and the local health department that their dental practice was not properly sterilizing equipment after use, instead "wiping them down with an intermediate disinfectant between patients." Additionally, the waterlines were not monitored or treated to meet CDC guidelines. (Two dentists at this practice corroborated this information.)¹¹

These instances reveal a troubling oversight in infection control: waterlines. When they aren't adequately maintained or monitored, patients are exposed to harmful contaminants that can pose serious health risks.

Navigating Compliance & Safety Measures

Industry guidelines for waterline safety can be vague, and enforcement varies widely by state. However, the CDC plans to release updated waterline maintenance guidelines in 2025, which are expected to provide more precise direction for effective practices to maintain safety standards.

The CDC currently outlines three essential "pillars" of dental water compliance¹²:

Surgical Water: Sterile water and sterile delivery systems for surgical procedures.
Dental Unit Water (≤500 CFU/mL): This involves chemical treatments, shock treatments, water reservoirs, and flushing air and water lines.
Verification of Compliance: Regular monitoring, testing, written operating procedures, and staff training.

To avoid noncompliance risks, dentists should adhere to the standard of care, which includes following CDC guidelines and State Dental Board regulations. Dr. Edwin Zinman, DDS, JD, highlighted four critical steps for compliance in the March/April 2020 issue of TIPS¹³:

Ensure that water used for routine dental treatment meets EPA standards for drinking water (≤500 CFU/mL of heterotrophic water bacteria).
Consult the manufacturer of your dental unit for proper usage methods and maintenance protocols to preserve water quality.
Follow manufacturer recommendations for monitoring water quality and using waterline treatment products.
Use saline or sterile water as a coolant and irrigant during surgical procedures.

Dr. Zinman also emphasized three additional strategies to protect your practice from liability:

Education: Train staff on waterline safety protocols.
Documentation: Maintain thorough records of waterline maintenance and compliance efforts.
Professional Services: Consider hiring a specialized service to monitor, treat, and maintain your dental unit waterlines.

As no federal mandate for DUWLs currently exists, it's wise to check with your state and local regulations. ProEdge Dental Water Labs, experts on dental waterline safety, offers an interactive map of state-by-state DUWL compliance standards.¹⁴

Make Clean Waterlines a Priority

In 2024, the ADA Forsyth Institute conducted a study¹⁵ to assess dental offices’ DUWL infection control practices. They discovered that most dental professionals acknowledge the importance of infection control but face barriers to implementation, including time, education, training, financial limitations, and staffing issues.

However, many Dental Boards are increasingly focused¹⁶ on dental water quality as more bacterial outbreaks occur and public scrutiny over PFAS exposure and water fluoridation continues to grow. Adding further complexity to this issue is the increased risk public water supplies face due to fires, floods, or other natural disasters. Clean water is an integral component of public health, and that extends to its use in dental practices. Ultimately, patients should leave their dental appointments in better health, not worse.

Patients put a tremendous amount of trust in their healthcare providers. While there are plenty of stories of incompetent dentists¹⁷ losing their way, most gladly uphold the standard of care. The issue simply comes down to this: If you were transparent about the monitoring, maintaining, and testing of your waterlines, would patients still choose your practice?

For more information on how to adequately monitor and maintain the safety of your dental unit water lines visit these resources for guidelines, tips, products, and support.

Author: With over 15 years as a published journalist, editor, and writer, Genni Burkhart's career has spanned politics, healthcare, law, business finance, technology, and news. She resides in Northern Colorado, where she works as the editor-in-chief of the Incisor at DOCS Education.

References:

Requirements for maintaining dental water lines - CDA. CDA. Published April 10, 2024. Accessed January 10, 2025. https://www.cda.org/newsroom/newsroom-archives/requirements-for-maintai…
WAC 246-817-660: Wa.gov. Published 2025. Accessed January 10, 2025. https://app.leg.wa.gov/wac/default.aspx?cite=246-817-660
Board of Dentistry Issues Notice of Intent to Adopt Dental Unit Water Quality Rule. State: GA - Georgia. Published 2024. Accessed January 20, 2025. https://www.gadental.org/latest-news/2024/12/20/board-of-dentistry-issu…
CDC. Best Practices for Dental Unit Water Quality. Dental Infection Prevention and Control. Published May 23, 2024. https://www.cdc.gov/dental-infection-control/hcp/dental-ipc-faqs/best-p…
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