36C25818Q0241-004.docx

Attachment C – Dental Water Testing Protocol Waterlines:

The Environmental Protection Agency (EPA), American Public Health Association and the American Water Works Association have defined the standard for US potable water – not to exceed 500 colony forming units (cfu) per milliliter of water. The Centers for Disease Control and Prevention (CDC) and the American Dental Association (ADA) have recommended dental unit water line (DUWL) deliver water should meet the U.S. potable water standard – not to exceed 500 cfu/ml of water. Dental services should routinely test water coming out of the DUWLs to meet this standard, have an action plan to meet this standard and to address a DUWL that exceeds this standard.

Waterline testing is to be accomplished by a laboratory certified (EPA or state) to perform environmental testing. VA Microbiology Laboratories perform clinical tests, and have not been approved for environmental testing.

The following is the recommended waterline protocol for VA Dental Services:

1. Dental unit water lines (DUWL) must be accessible for treatment – daily and for shocking, as needed. That requires a water bottle (reservoir) on the unit or some means to access the DUWLs.

0. Replace/change any units with direct connection to municipal water.

1. Provide an ongoing water treatment program. There are multiple choices. Among the most common are those that involve placing a tablet in the reservoir and those that have a reservoir draw-tube which treats the water.

Testing protocol

1. Test each line separately

1. Remove all handpieces and any other equipment reprocessed by SPS before drawing samples from the lines. Air-water syringe tips should be removed. The air-water syringe itself, if not changed between patients (e.g., if barrier + disinfection is accomplished by dental personnel), should remain on the line while drawing the sample.

1. Quarterly

1. Use a lab certified to do water testing

1. Report results to the Infection Control Committee Action Levels

1. If >200 cfu but <500 cfu

5. Shock all lines in the unit (i.e., the dental treatment room)

0. Leave the air-water syringe on the line if not reprocessed by SPS

5. Line can stay in service

5. No retest needed after shocking

2. Maintain the unit's place in the quarterly testing sequence

1. If >500 cfu

6. Take line out of service (the >500 cfu line only – other sub-500 cfu lines may stay in service)

6. Shock all lines to unit per manufacturer's instructions

1. Leave the air-water syringe on the line if not reprocessed by SPS

6. Retest the >500 cfu line before returning it to service

1. If shocking and retesting again yields >500 cfu

7. Line remains out of service

7. Contact dental equipment manufacturer and waterline treatment manufacturer for recommendations on options, such as repeat shocking or line replacement Feed Water (water supplied to the reservoir)

1. Generally tap, distilled, de-ionized or sterile water is acceptable (see manufacturer’s recommendations). Also, at least one manufacturer has a sequential cartridge system which produces treated water for the reservoir.

Note: All recent Legionella occurrences in VA have involved municipal water. There is no advantage to filling dental unit reservoirs with sterile water. Typical dental units are not designed to deliver sterile water, and therefore this does not meet sterile water surgery requirements. Sterile water in reservoirs does not prevent biofilm formation in DUWLs.

Sterile saline or sterile water for surgical procedures Note: Placing sterile saline/water in a dental unit reservoir does not constitute sterile irrigation at the surgery site

1. Surgical procedures are those involving the incision, excision, or reflection of tissue that exposes normally sterile areas of the oral cavity, such as:

9. biopsy

9. periodontal surgery

9. apical surgery

9. implant surgery

9. surgical extraction of teeth (flap elevation, bone removal or tooth sectioning) At time of publication at least one manufacturer offers an equipment system that delivers sterile irrigants via sterile reservoir and sterile lines through the sterile handpiece. At least one manufacturer offers a device to deliver sterile irrigants via an assistant handheld device to the surgical site. These systems do not require waterline testing, as sterile irrigant is used in a sterile system.

At the end of the work week, the water reservoir may be removed and drained, allowing the reservoir to dry over the weekend.

1. Tablet treatments added to the reservoir have expiration timeframes after mixing, commonly 2-4 weeks, depending upon the manufacturer. Emptying the reservoir weekly ensures no solution becomes expired.

· If tablet system reservoirs are not emptied weekly, the dental service will need to identify how tablet expiration is monitored. An expiration label on the reservoir is one example.

1. If using a draw-tube system, water may not be effectively treated until it is drawn into the tube. (Checking with the draw-tube manufacturer is recommended.) Allowing the reservoir to dry reduces the risk of biofilm forming in the reservoir.

Testing each individual waterline separately (as opposed to combining all the unit's lines into one sample) is for the following reasons:

1. If a line exceeds 500 cfu, only that line needs to be taken out of service until shocked and retested. The remainder of the unit's lines may well be functional during the shocking process.

0. Often it's the least used line that forms biofilm

1. Combining lines into one sample adds a dilution factor. For example, assuming equal amounts of water from 5 lines, a report of 100 cfu needs to assume a worst case scenario – that 1 line was 500, and the other 4 were zero (the 1:4 dilution factor). The entire unit needs to be taken out of service until shocked and retested.

Ideally personnel other than dental personnel will accomplish waterline testing. This is a local, resource dependent decision. Drawing waterline samples and submission of the samples for testing requires a competency document be accomplished, with associated annual validation. Test results, actions and outcomes should be reported to the local Infection Control Committee.