| FAQ - Dental Unit Waterlines - 2013
It is recommended that waterlines be flushed 20-30 seconds after each patient. What is the recommended time to flush the lines first thing in the morning?
The 2003 US Centers for Disease Control and Prevention (CDC) infection control guidelines for dentistry says the following:
Strategies To Improve Dental Unit Water Quality
In 1993, CDC recommended that dental waterlines be flushed at the beginning of the clinic day to reduce the microbial load (2). However, studies have demonstrated this practice does not affect biofilm in the waterlines or reliably improve the quality of water used during dental treatment (315,338,343). Because the recommended value of <500 CFU/mL cannot be achieved by using this method, other strategies should be employed. Dental unit water that remains untreated or unfiltered is unlikely to meet drinking water standards (303--309). Commercial devices and procedures designed to improve the quality of water used in dental treatment are available (316); methods demonstrated to be effective include self-contained water systems combined with chemical treatment, in-line microfilters, and combinations of these treatments. Simply using source water containing <500 CFU/mL of bacteria (e.g., tap, distilled, or sterile water) in a self-contained water system will not eliminate bacterial contamination in treatment water if biofilms in the water system are not controlled. Removal or inactivation of dental waterline biofilms requires use of chemical germicides.
Patient material (e.g., oral microorganisms, blood, and saliva) can enter the dental water system during patient treatment (311,344). Dental devices that are connected to the dental water system and that enter the patient's mouth (e.g., handpieces, ultrasonic scalers, or air/water syringes) should be operated to discharge water and air for a minimum of 20--30 seconds after each patient (2). This procedure is intended to physically flush out patient material that might have entered the turbine, air, or waterlines. The majority of recently manufactured dental units are engineered to prevent retraction of oral fluids, but some older dental units are equipped with antiretraction valves that require periodic maintenance. Users should consult the owner's manual or contact the manufacturer to determine whether testing or maintenance of antiretraction valves or other devices is required. Even with antiretraction valves, flushing devices for a minimum of 20--30 seconds after each patient is recommended.
VIII. Dental Unit Waterlines, Biofilm, and Water Quality
A. General Recommendations
1. Use water that meets EPA regulatory standards for drinking water (i.e., <500 CFU/mL of heterotrophic water bacteria) for routine dental treatment output water (IB, IC) (341,342).
2. Consult with the dental unit manufacturer for appropriate methods and equipment to maintain the recommended quality of dental water (II) (339).
3. Follow recommendations for monitoring water quality provided by the manufacturer of the unit or waterline treatment product (II).
4. Discharge water and air for a minimum of 20--30 seconds after each patient, from any device connected to the dental water system that enters the patient's mouth (e.g., handpieces, ultrasonic scalers, and air/water syringes) (II) (2,311,344).
5. Consult with the dental unit manufacturer on the need for periodic maintenance of antiretraction mechanisms (IB) (2,311).1
The American Dental Association (ADA) Statement on Dental Unit Waterlines says the following:
In 1993, CDC recommended that dental waterlines be flushed at the beginning of the clinic day to reduce the microbial load. However, studies have demonstrated this practice does not affect biofilm in the waterlines or reliably improve the quality of water used during dental treatment. Dental unit water that remains untreated or unfiltered is unlikely to meet drinking water standards, <500 CFU/mL, therefore, one or more commercial devices and procedures designed to improve the quality of water should be employed. At the present time, commercially available options for improving dental unit water quality include the use of:
· Independent water reservoirs
· Chemical treatment regimens
· Source water treatment systems
· Daily draining and air purging regimens
· Point-of-use filters
Additionally, strict adherence to maintenance protocols is required to sustain the quality of dental unit water. Industry and independent researchers are strongly encouraged to continue to explore the possible alternatives and adjuncts to the above listed options. Dental practitioners should always consult with the manufacturer of their dental units before initiating any waterline treatment protocol.2
It is recommended that you contact the manufacturer of your equipment regarding this question because recommendations for dental unit waterline flushing can vary by product and manufacturer.
1) Kohn WG, Collins AS, Cleveland JL, Harte JA, Eklund KJ, Malvitz DM, Centers for Disease Control and Prevention (CDC). Guidelines for infection control in dental health-care settings—2003. MMWR Recomm Rep 2003;52(RR-17):1-61. Accessed on January 29, 2013 http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5217a1.htm .
2)American Dental Association. Statement on Dental Unit Waterlines. Accessed on January 30, 2013 http://www.ada.org/1856.aspx .