There is no better way to have control of dental unit water lines than with the use of water bottles on the dental unit. All manufacturers of dental units today have water bottles as standard equipment. Older units can be equipped with a basic water bottle system for less than $150 each. The system can be configured to feed the water to the handpieces, syringes, and the ultrasonic scaler. If you use a cuspidor, it need not be fed from the water bottle, but the cup-filler should be.
Why do we recommend water bottles? Simply put, the reason is control. Through the water bottle, we can introduce chemicals which will kill biofilms, inhibit their growth and/or feed an assortment of other hygienic chemicals that are produced. Deluxe systems are available with dual bottles - one bottle can hold distilled water, while the other can contain a cleaning chemical or medicament.
If you use water bottles, some things must be done to ensure that biofilms do not contaminate the lines, even if you use distilled water. If you add water bottles to existing units, have the service technician perform an initial cleaning of the lines when he installs the bottles. Ask your dealer for approved chemicals which will kill biofilms. Then follow the protocol outlined in Table 1.
Note: Whatever you use for cleaning, check the water lines periodically for biofilm contamination. You do not have to check every line each time. For example, test a syringe and one handpiece in one or two rooms. Three months later, check the lines in another room, etc. A test kit is available from Pall Medical through your dealer.
If you use bottles - and testing reveals that biofilms have invaded the lines - increase the frequency of cleaning your lines as I described above, or review your own method of cleaning for possible errors.
Ask your dealer about the chemicals available for cleaning the lines and for patient use. Solutions are available which can be added to your water bottle. They are not harmful to the patient and will inhibit growth of biofilms.
Now I want to point out some obvious things, but possibly some things you haven’t considered:
➥Distilled water is not sterile water.
➥Just using sterile water does not make the water exiting the handpiece sterile. The whole idea of using a self-contained, water-bottle system is not to provide sterile water, but to control the environment of the dental unit water lines.
➥No matter what product you use in the water bottle, it does not exclude the need for periodic cleaning of the water lines.
➥To be sure of the efficacy of your efforts, periodic testing of your water by a third party is advised.
Dave Cheney is a retired service technician from Patterson Dental with more than 30 years in the dental industry. He is the author of “Doctor, Did You Check the Breaker, Too?,” a manual written to assist the dental staff in analyzing and performing minor equipment repairs when a technician is not warranted or not readily available. To order the manual as a book or CD, call (800) 695-0943. You may also order online through his Web site at www.davandental.com.
dental unit water lines
1. Install a dry bottle.
2. Blow out all of the lines with the air (only) from the empty bottle, expelling the water in the lines. Don’t forget the syringe and Cavitron®.
3. Fill a bottle with the suggested concentrate of the biofilm-killing chemical and tap water.
4. Introduce the chemical into the lines with the purge switch or foot controller. Keep it going until the solution begins to come out of every line. Note: Most of these chemicals are detrimental to fabrics, so protect clothing, carpets, and chair upholstery.
5. Leave the chemical in the lines for the prescribed time. You can use the same mixture for several units at one time.
6. Install a dry bottle and expel all of the chemical from the lines.
7. Install a bottle with distilled water and thoroughly flush all remaining chemicals.
8. Instead of using produced chemicals, bleach can be used. Dilute the bleach 10:1 with tap water (one part bleach, nine parts water). Leave it in the system only 10 minutes, then flush.
9. This protocol should be repeated weekly.