Oral Health Topics
Waterlines, Dental Unit
In our environment, we are exposed to countless germs or bacteria. These common microbes or germs accumulate inside things like showerheads, faucets and fountains, and in the thin tubes used to deliver water in dental treatment. Patients should always feel free to ask their dentist about water quality or any other aspect of their practice.
- What are biofilms?
- Will biofilms harm me?
- What is the recommendation for dental unit water quality?
- Is the water in my dentist's office safe?
- What should patients know about waterlines?
Biofilms are microscopic communities that consist primarily of naturally occurring water bacteria and fungi. They form thin layers on virtually all surfaces, including dental water delivery systems. These common microbes or germs accumulate inside things like showerheads, faucets and fountains, and in the thin tubes used to deliver water in dental treatment.
In our environment, we are exposed to countless germs or bacteria. Yet, exposure to these common microbes does not mean that an individual will get an infection or a disease. However, when a person’s immune system is compromised because of age, smoking, heavy drinking, being a transplant or cancer patient or because of HIV infection, he or she may have more difficulty fighting off the invading germs. This is why the ADA encourages patients who may have weakened immune systems to inform their dentist at the beginning of any treatment. That way, the patient and dentist together can make the right treatment decisions.
The CDC recommends that dental unit water meet the standard set for drinking water, which is a limit of 500 colony forming units of bacteria per milliliter of water.
Patients should feel free to ask their dentist about the quality of their dental treatment water or any other aspect of their practice. To help reduce the number of microorganisms in treatment water, the Association recommends that dentists follow the infection control guidelines of the CDC and ADA. This is in addition to other precautions that your dentist may have in place.
Patients should always feel free to ask their dentist about water quality or any other aspect of their practice. Patients also should inform their dentist of any health problems and medications they might be taking so the patient and dentist can make the right treatment decisions.
Drinking water must meet a certain standard with respect to concentrations of contaminants and chemicals. The maximum concentration of heterotrophic bacteria set by the EPA, the American Public Health Association (APHA) and the American Water Works Association (AWWA) is 500 colony-forming units per milliliter (CFU/ml) of drinking water.
The quality of water delivered by dental units will not meet this standard without regular maintenance. In fact, research has shown that microbial counts can be as high as 200,000 CFU/ml within 5 days of installation of new dental unit waterlines; and, without maintenance, levels as high as 106 CFU/ml of dental unit water have been found. The small diameter of dental waterline tubing, combined with their design and flow rate, enable bacteria and other microorganisms to form a biofilm that coats the inside of the tubing. As the water travels through the waterlines the microorganisms slough off resulting in contamination of the water.
- A Simulated-Use Evaluation of a Strategy for Preventing Biofilm Formation in Dental Unit Waterlines (June 2004)
- A Review of the Science Regarding Dental Unit Waterlines (September 2002)
- Evaluation of a Hydrogen Peroxide Disinfectant for Dental Unit Waterlines (September 2001)
- The Effect of a Dental Unit Waterline Treatment Regimen on the Shear Bond Strength of Resin-Based Composite (May 2001)
- The Dental Unit Waterline Controversy: Defusing the Myths, Defining the Solutions (October 2000)
- ADA Statement on Dental Unit Waterlines
- ADA Statement on Infection Control in Dentistry
- Dental Unit Waterlines: Cleaning Waterlines (PDF)
- Oral Health Topics: Infection Control