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H2O so simple: Simplicity should be the key in ensuring dental water is as safe as drinking water

Sept. 20, 2016
Infection control expert Noel Kelsch says simplicity should be the key in ensuring dental water is as safe as drinking water.

By Noel Kelsch, RDH, RDHAP, MS

The simplest things in life can get deceptively complex at times. One such area that eludes many is water. Water is such a simple element that many of us take for granted. It is made up of two-parts hydrogen and one-part oxygen. Simple? Maybe, maybe not.

In the dental environment, we use water in different ways. We may offer a glass to a patient. We use it in most dental procedures, ranging from tap water to sterile water for surgical procedures. But when is the last time you checked the safety of the water you are using for dental procedures? Are you sure the water you are utilizing is safe and dependable? Are you treating to reduce the bacterial level to the standards required?

This simple concept eludes many dental health-care professionals (DHCP) to the point that they may not even be addressing the issue. This has been an ongoing issue, and a national news story just proved how important water is to the safety of our patients.

When parents take their child to the dentist, they assume that the office will do everything they can to keep that child safe. In September 2015, it was discovered to not be the case in a Georgia office. A hospital notified the Centers for Disease Control and Prevention (CDC) that there was a cluster of pediatric Mycobacterium abscessus odontogenic infections. Nine children developed the infection after having a pulpotomy at pediatric dentistry practice.1

What is M. abscessus? It is s a rapidly growing nontuberculous mycobacterium (NTM). It is found in soil, dust, and water! M. abscessus can cause skin and soft tissue infections. It also can impact the organs. According to the CDC, the Issue here is that "NTM species display tolerance to commonly used disinfectants and are frequently found in the plumbing of health care facilities and water distribution systems."

If DHCP do not take care of waterlines, it will allow the growth and amplification of microorganisms, including this hardy bacteria. The thin, narrow tubing of waterlines along with the inconsistent water flow and potential for retraction of oral fluids in the dental setting give the perfect scenario for biofilm to adhere, and replication of this bacteria can get out of control. This bacteria, once it enters the body, can cause a severe infection in immunocompetent children, and poses a contamination risk. For the immunocompromised patient, this would even be a greater risk.

The Georgia office was evaluated for their infection control practices. The infection control breaches recognized included:

  • They were not following the instructions for use (IFU) for the dental unit they were using. It is required by the Food and Drug Administration (FDA) that you follow the IFU for use on the FDA medical devices you are using and that you train the staff to those measures.2
  • They used tap water for the pulpotomies without water quality monitoring or treating of waterlines at the end of each day, as recommended in the manufacturer guidelines of their unit.
  • Water samples taken for the units were well above the 500 CFU/ml (drinking water standard) that is required in the dental setting-the average being 91,333 CFU/ml.

M. abscessus was found in all water samples, and testing revealed that it was from a common source. The outbreak of the nine patients came from this source.

Here is where it gets simple. To prevent this from occurring in your office, there are a few things you need to do:3,4

  1. Read the IFU for your unit and follow the instructions for disinfecting your waterline. If you do not have them, call the manufacturer and get them. Train your staff about the IFU.
  2. Follow manufacturer's recommendations for monitoring the quality of the water to ensure that the recommended bacterial counts are being adhered to. All dental units should use systems that treat water to meet drinking water standards (i.e., ≤ 500 CFU/mL of heterotrophic water bacteria).
  3. Independent reservoirs or water-bottle systems alone are not sufficient. Commercial products and devices are available that can improve the quality of water used in dental treatment. Consult with the dental unit manufacturer for appropriate water maintenance methods and recommendations for monitoring dental water quality.
  4. During surgical procedures, you must take the next step of using an appropriate delivery device such as a bulb syringe or sterile tubing/single use devices that bypasses the dental unit waterline.4
  5. Discharge water and air for a minimum of 20 to 30 seconds after each patient, from any device connected to the dental water system that enters the patient's mouth (for example, handpieces, ultrasonic scalers, and air/water syringes).3
  6. Consult the dental unit's manufacturer for the need to periodically maintain anti-retraction devices.

There are many methods of keeping the bacterial levels down in a unit. It is important to do what the manufacturer recommends. Some methods include:

  1. An alternate water supply that is able to bypass the community water system. This has to be combined with chemical treatment.
  2. Ultraviolet irradiation of water before entrance into individual unit waterlines.
  3. In line filters that remove bacteria right before it goes into the dental unit attachements.
  4. Chemical disinfection involving periodic flushing of lines with a disinfectant followed by appropriate rinsing of lines with water or a continuous release chemical disinfection system.
  5. Thermal inactivation of facility water at a centralized source.
  6. Reverse osmosis or ozonation using units designed for either single chair or entire practice waterlines.7-9

The most common way for maintaining a dental waterline is via a cleaning agent. This can be in table form or as simple as a device that slowly releases chemicals into the system. So what do you need to look for in dental water line cleaning agents?3,7-9

  • Reliability and ease of use. There are some great new products on the market that are time released to simplify the process.
  • Noncorrosive to metals and line tubing, which can be rubber or synthetic
  • Nontoxic to equipment or patients
  • Ability to interrupt biofilm formation and rapid antimicrobial action
  • Nonpyrogenic and nonallergenic
  • Does not interfere with performance of any dental restorative or therapeutic agents
  • Does not impact the environment
  • Exhibit broad-sprectrum antimicrobial activity against bacteria, fungi, and protozoa
  • Exhibit substantivity to minimize or prevent microbial accumulation on treated surfaces

Test when you try a new product and periodically to make sure the protocol you are following is working. These tests are available through dental supply companies and can confirm you are in the 500 CFU/ml guideline.

Water is one of the simplest things in dentistry where our attention to detail can make the difference in the outcome. Simple things do make a difference. RDH

NOEL BRANDON KELSCH, RDH, RDHAP, MS, is a syndicated columnist, writer, speaker, and cartoonist. She serves on the editorial review committee for the Organization for Safety, Asepsis and Prevention newsletter and has received many national awards. Kelsch owns her dental hygiene practice that focuses on access to care for all and helps facilitate the Simi Valley Free Dental Clinic. She has devoted much of her 35 years in dentistry to educating people about the devastating effects of methamphetamines and drug use. She is a past president of the California Dental Hygienists' Association.


  • http://www.cdc.gov/mmwr/volumes/65/wr/mm6513a5.htm
  • http://emergency.cdc.gov/han/han00382.asp accessed July 1.
  • Kohn WG, Collins AS, Cleveland JL, Harte JA, Eklund KJ, Malvitz DM; Guidelines for infection control in dental health-care settings-2003. MMWR Recomm Rep 2003;52(No. RR-17).
  • Centers for Disease Control and Prevention. Summary of Infection Prevention Practices in Dental Settings: Basic Expectations for Safe Care. Atlanta, GA: US Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Division of Oral Health; March 2016.
  • Molinari J, Harte J. Practical Infection Control in Dentistry. 3rd Edition. Baltimore, MD: Lippincott Williams and Wilkins, 2009. Print.
  • Mills SE. Dental unit water and air quality challenges. In: Molinari JA, Harte JA, eds. Cottone's Practical Infection Control in Dentistry. 3rd ed. Philadelphia: Wolters Kluwer/ Lippincott Williams & Wilkins; 2009:63-75.
  • Molinari JA. Dental unit water contamination. Compend Contin Ed Dent. 1999;20:358-362.
  • Molinari JA. Principles of dental waterline asepsis. Dental Economics. Available at: www.dentaleconomics.com/display_article/363284/54/none/none/Colum/Principles-of-dentalwaterline-asepsis. Accessed July 16, 2016.