Dental Unit Waterline Contamination: Causes, Concerns, 3rd edition

About the Course
This course offers a comprehensive overview of the problem of dental unit waterline (DUWL) contamination. The Environmental Protection Agency regulates drinking water in the public water supply to ensure that the number of water organisms is kept at an acceptable level. The Centers for Disease Control and Prevention recommends that the water emitted from dental handpieces and air/water syringes be the same quality as drinking water. 

Due to the extremely narrow DUWL tubing through which patient treatment water is delivered, and the frequent periods of water stagnation, the inner surfaces of tubing provide a particularly favorable environment for the multiplication of microorganisms. Contact of the oral cavity or other routes of entry with water from a dental unit containing large numbers of microorganisms is incompatible with infection control standard of care and inconsistent with the public’s expectations of modern dentistry. 

It is widely accepted that dental unit waterline contamination be controlled to protect dental workers and patients from aerosolized, inhaled, and ingested microbes. Therefore, dental practitioners should have an understanding of the problem and current approaches to improving the quality of the water in dental units.  

This basic-level course discusses the complexity of DUWL contamination and the importance of monitoring contamination levels. The methods used to control microbial growth and the limitations associated with current approaches are also explained. Participants learn how to judiciously choose a DUWL disinfectant best suited to their practice needs.

Learning Objectives
  • Identify the causes of dental unit waterline contamination.
  • Describe national standards and guidelines for dental unit waterline quality.
  • Describe the types of microorganisms recovered from dental unit waterline.
  • Explain the consequences of dental unit waterline contamination.
  • Identify the current approaches to improving dental unit waterline quality and their limitations.
  • Explain the rationale and methods available for monitoring dental unit waterline quality.
About the Author
Nuala B. Porteous, BDS, MPH, received her bachelor of dental surgery degree (equivalent to the American DDS) in 1976 from University College Cork, Ireland. She earned her master’s in public health degree from The University of Texas Health Science Center (UTHSC), School of Public Health, at Houston in 1992. Dr. Porteous is a diplomate of the American Board of Dental Public Health. She is currently an associate professor/researcher in the Department of Comprehensive Dentistry, UTHSC San Antonio (UTHSCSA) Dental School. She has held previous faculty appointments at UTHSCSA in the Department of Community Dentistry as clinical instructor (1995 to 1998), assistant professor (1998 to 2005), associate professor (2005 to 2007), and infectious diseases fellow in the Department of General Dentistry (2000 to 2002). Dr. Porteous is a member of the American National Standards Institute/American Dental Association Standards Committee for Dental Products. Her research activities include infection control, with a particular focus on dental unit waterline contamination. She has authored or coauthored numerous articles in peer-reviewed scientific journals and has presented her research at numerous national and international scientific meetings.

AGD Subject Code: 148

How to Receive Credit
  • Read the entire course online or in print.
  • Depending on your state requirements you will be asked to:
  • Complete a mandatory test (a passing score of 75 percent is required). Test questions link content to learning objectives as a method to enhance individualized learning and material retention.
  • Provide required personal information and payment information.
  • Complete the mandatory Course Evaluation.
  • Print your Certificate of Completion.
Resolution of Conflict of Interest

Colibri Healthcare, LLC implemented mechanisms prior to the planning and implementation of the continuing education activity, to identify and resolve conflicts of interest for all individuals in a position to control content of the course activity.

Sponsorship/Commercial Support and Non-Endorsement.
It is the policy of Colibri not to accept commercial support. Furthermore, commercial interests are prohibited from distributing or providing access to this activity to learners.

The information provided in this activity is for continuing education purposes only and is not meant to substitute for the independent medical judgment of a healthcare provider relative to diagnostic and treatment options of a specific patient’s medical condition.

©2020: All Rights Reserved. Materials may not be reproduced without the expressed written permission or consent of Colibri Healthcare, LLC. The materials presented in this course are meant to provide the consumer with general information on the topics covered. The information provided was prepared by professionals with practical knowledge of the areas covered. It is not meant to provide medical, legal, or professional advice. Colibri Healthcare, LLC recommends that you consult a medical, legal, or professional services expert licensed in your state. Colibri Healthcare, LLC has made all reasonable efforts to ensure that all content provided in this course is accurate and up to date at the time of printing, but does not represent or warrant that it will apply to your situation nor circumstances and assumes no liability from reliance on these materials. Quotes are collected from customer feedback surveys. The models are intended to be representative and not actual customers.