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  • Dentists
  • Dental Hygienists
  • Dental Assistants
Hours: 1 Contact Hour
Author(s): Nuala B. Porteous, BDS, MPH
Peer Reviewer(s): Shannon E. Mills, DDS, FAGD, FICD
Item#: L0716
Contents: 1 Course Book (34 pages)
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Dental Unit Waterline Contamination: Causes, Concerns, and Control, Updated 1st Edition

Price $9.95
Item # L0716
When available, the Online Course format is included with the hard copy, eBook, or audio book formats!

Original Release Date: November 2, 2012

Review Date: October 22, 2015

Expiration Date: April 21, 2021

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.
AGD Subject Code: 148

Western Schools designates this activity for 1 continuing education credit.

Course 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 waterlines.
  • 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.

Nuala B. Porteous, BDS, MPH, received her bachelor (the Irish equivalent of the American doctorate) of dental surgery degree (BDS) from University College Cork, Ireland, in 1976. She earned her master’s in public health degree (MPH) from The University of Texas Health Science Center (UTHSC), School of Public Health, at Houston in 1992. She is a diplomate of the American Board of Dental Public Health. She is currently an associate professor/research 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 a clinical instructor (1995-1998), assistant professor (1998-2005), associate professor (2005-2007), and infectious diseases fellow in the Department of General Dentistry (2000-2002). 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 scholarly articles in peer-reviewed scientific journals and has presented her research at many national and international scientific meetings.

Shannon E. Mills, DDS, FAGD, FICD, is vice president for professional relations and science for Northeast Delta Dental in Concord New Hampshire. Dr. Mills retired from the U.S. Air Force as a colonel in 2005. He has authored or coauthored numerous articles on dental infection control in peer-reviewed journals and was a member of the American Dental Association (ADA) panel that drafted the 1995 statement on dental unit waterlines. He is a consultant to the ADA Council on Scientific Affairs and contributed to the 2003 CDC Guidelines for Infection Control in Dental Health-Care Settings. Dr Mills was chair of the Organization for Safety, Asepsis and Prevention from 2001 to 2002. He currently serves as a committee chair for the ADA/American National Standards Institute Standards Committee for Dental Products and is a member of the U.S. delegation to ISO Technical Committee 106, Dentistry.

  • Courses must be completed on or before the expiration date noted in the course description above.
  • You must score 75% or higher on the final exam and complete the course evaluation to pass this course and receive a certificate of completion.
  • All persons involved in the planning and development of this course have disclosed no relevant financial relationships or other conflicts of interest related to the course content.
  • Through our review processes, Western Schools ensures that the course content is presented in a balanced, unbiased manner and is free from commercial influence.
  • There are no prerequisites for this course.
  • Shannon E. Mills has disclosed that he is a copatent holder for Air Controlled Sterile Irrigation System, marketed under license from the U.S. Air Force by Aseptico, Inc., Woodinville, WA. Western Schools ensures that this content is free from bias and commercial influence through its peer-review process.