Failing to plan, is planning to fail - get your dental water lines ready...
Management of waterborne pathogens in dental unit water lines during the COVID-19 Pandemic!
First off, thank you for taking great care of your patients. Infection prevention has never been so important and although many of other issues are on your mind you may find yourself at the point where you will have to consider suspending or limiting the care.
Some practices are reaching out to us with questions regarding waterline maintenance given that many of you may have to close down the surgeries. We've been advising you on the dental lines disinfection procedures for a while and this time is no different. We would like to help you understand how to mitigate the rapid biofilm development within your DUWL during the shutdown or reduced use of your equipment.
Whilst water systems may not seem to be high on the priority list during the COVID-19 pandemic it is important for the health and safety of patients, staff, and visitors is maintained and all water systems are managed safely. Bacteria may grow and develop biofilms, which, combined with the generation of aerosols from high speed powered hand-pieces and ultrasonic devices, may expose your patients to microbial pathogens including Legionella, Pseudomonas and Mycobacterium species.
Recommended Protocol If You're Suspending or Limiting Care:
Recommended Shut Down Procedure
As outlined in HTM 01-05, follow the manufacturer’s guidance (This refers to dental unit manufacturer) for the temporary decommissioning of DUWLs.
1. Purge Your Waterlines: Purge or drain all water from all waterlines including syringes, high-speed handpieces and ultrasonic scalers (e.g. Cavitrons) and let lines dry. Verify that your Slow Speed Handpiece lines are capped by attempting to purge water from them. If water comes out, completely purge these lines as well. Leave lines completely dry until the practice resumes care.
2. If Using Tablets or other Waterlines Maintenance Products: Purging may not be necessary, but we recommend it across the board in this situation.
3. If Using Straws: Purging water from the lines is recommend with straws with prolonged non-use. The straw can be left on the pick-up tube with the bottle reattached. (Refer to the manufacturer guidance)
In the absence of manufacturer’s guidance, flush, drain and leave disconnected during any temporary closure for each surgery. If this is not practicable, they should be flushed on a weekly basis (as outlined in HTM 01-05). Self-contained water bottles (bottled water systems) should be removed, flushed with distilled and/or reverse osmosis (RO) water, emptied and stored inverted to dry during the temporary closure.
Recommended Start-up Procedure
1. Clean and disinfect your waterlines upon return: Before resuming care on your dental unit, thoroughly shock the DUWL regardless of the maintenance product you use! Remember, there is a big difference between ongoing maintenance products and DISINFECTANTS (SHOCK TREATMENT)!
NOTE: Always check manufacturer’s instructions for your equipment and shock product. Different chair manufactures suggest different shock protocols and different treatment products call for different techniques
Where in-line filters are present, these will also require replacement or treatment using a cleaning solution as recommended by the manufacturer and this step should be performed after the first DUWL flush. Ensure that any other disposable filters are changed as per manufacturer’s instructions.
2. Flush the entire system and test your dental unit water lines after disinfection: Once your DUWL are disinfected (shocked)
3. Test your dental unit water quality (at least 48 hours after any disinfection) to ensure biofilm development during non-use is completely cleaned and guidelines are met. It would be wise to use UKAS accredited method of sampling. HTM 01-05, states that ‘All microbiological measurements should be by approved methods and / or be carried out by United Kingdom Accreditation Service (UKAS) accredited laboratories. Dip slides are not acceptable’ (paragraph 19.68).
4. Keep record of all actions and water sampling taken during the decommissioning and decommissioning.
"WHILE THE USE OF DIP SLIDES IS NOT ADVOCATED BY HTM 01-05 AS THEY ARE NOT SENSITIVE ENOUGH FOR USE AS A TEST FOR DRINKING WATER QUALITY, NOR DO THEY DETECT LEGIONELLA, THEY ARE QUITE CAPABLE OF DETECTING THE HIGHER NUMBERS OF BACTERIA ASSOCIATED WITH THE PRESENCE OF BIOFILMS, SO THEY COULD BE USED FREQUENTLY AS AN INEXPENSIVE METHOD OF TRENDING AND CHECKING THAT GROSS BACTERIAL INVASION IS NOT OCCURRING.
WHERE DIP SLIDES ARE TAKEN, THEY SHOULD BE USED ACCORDING TO THE MANUFACTURER’S INSTRUCTIONS. IT SHOULD BE NOTED THAT THE USE OF DIP SLIDES FOR HETEROTROPHIC BACTERIA DOES NOT PROVIDE INFORMATION ON THE PRESENCE OF PATHOGENS."
DIP SLIDES will NOT test your lines for presence of viruses like COVID-19!
Sylwia Leszkiewicz MWSOC
Director & Senior Legionella Consultant