Closing and reopening your Practice

If dental chairs are scheduled to be closed for an extended period (more than 4 days is considered a reasonable measure) you should implement precautions to ensure the chair is safe for use on resumption. This can be done in a couple of ways.

• You can purge all water from the DUWLs and air dry as per accepted end of day practice, noting that completely drying DUWLs is difficult in some chairs.
• Alternatively, you can use a purpose made sanitising solution which can be introduced into the DUWLs via the water bottle. The fluid would remain in situ for the duration of the chair closure.
• (Ensure the product is designed to stay in the chair for the closure period and check the suitability of the product for your chair.)
• When you reopen ensure, the sanitising solution is flushed from the system as per the product IFU and follow up by flushing all lines for 2 minutes as per start of day protocol.

To avoid biofilm growth there are several strategies that can be employed:

Water quality: 

Should be of a potable standard as outlined by the Australian Drinking Water Guidelines (updated August 2018) which stipulates that the number of bacteria in water used as a coolant or irrigant for non-surgical dental procedures should be less than 200 CFU/ml (colony forming units/ml). It is important that you check your water quality using either a commercially available kits e.g. a dip slide kit or processing samples through a NATA certified laboratory. Ensure all lines are included in the sample.

Chlorine/Chloramine levels measurement:

Adequate Chlorine/Chloramine levels is a valuable tool to reduce biofilm growth SAWater - Disinfecting your drinking water

Flushing DUWLs: 

This is an important process in reducing biofilm and should be part of your daily practice. The turbulent flow created acts to flush any unestablished/immature biofilm out of the DUWL. The current ADA Guidelines for Infection Prevention and Control pg. 30 stipulates flushing for 2 minutes at start of day and at least 30 seconds after each patient.

Use of Preventors: 

There are a range of products you can use to prevent the growth of biofilm including hydrogen peroxide, hypochlorites, chloramines, iodine and silver ions. Be aware that these work better on new or shocked DUWL that haven't had a chance to grow biofilm. Be aware that products recommended for European manufactured chairs may vary from chairs manufactured in the United States.

Non return valves: 

All DUWLs should be fitted with anti-retraction valves to prevent water contaminated from the patient's mouth being drawn back into the DUWL when the water flow is snapped shut. Check with your chair supplier or technician if you are unsure.

DUWL shock treatment: 

If you find that your CFU count is >200 CFU/ml you can do a shock treatment of the DUWLs which strips out any biofilm. It is important to ensure that the product is compatible with your chair and that it is completely removed prior to recommissioning. For this reason, it is recommended that you get a qualified technician to do this, so contact your chair supplier or manufacturer.

Bottled Chairs: 

Bottles have advantages over mains connected chairs because you can easily dose chairs if required, with either biofilm preventors shock or hibernation treatments. Using bottles also allows DUWL to be air dried using an empty bottle at end of day or when closing the chair for a longer period.

Mains supplied chairs typically require qualified technicians to access the DUWL through the floor box in the base of the chair, although some mains fed chairs do include line flushing and chemical dosing ports incorporated into the mains waterline.

It is strongly recommended that you ensure that your practice has a:

• DUWL flushing schedule in place
• Water testing schedule in place particularly where high levels of CFU's are measured
• DUWL treatment program in place for both everyday use and if a chair is closed for an extended period of time (>4 days)

Resources

The ADA Guidelines for Infection Prevention and Control - Fifth Edition (p32-35) provide detailed guidance on waterline management and water quality maintenance procedures to be followed in dental practice. Click here for the link to the ADA Guidelines for Infection and prevention Control, or visit our Infection Control Assessment Program page.

Any Questions! 

If you have any queries regarding DUWLs or any other infection control matters, please contact our Infection Control and Prevention Officer via canderson@adasa.asn.au or phone 8272 8111.

We offer comprehensive advice on individual issues or group training sessions that can cater for a broad range of infection control topics and how they relate to your specific setting. In addition, we can provide a clinic audit and feedback session which ensures your clinic is operating to the latest standards. If you would like to book your infection control assessment program session, click here or email membership@adasa.asn.au