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Dental unit waterline and independent water bottle

Also called: water bottle, self-contained water system, DUWL

The bottle and thin tubing that supply water to handpieces, scalers and the syringe.

Many dental units get their water from a bottle attached to the unit (an independent or self-contained water system). The narrow tubing grows biofilm (a slimy layer of germs) unless it is treated with chemicals. Water used for nonsurgical care should have 500 CFU/mL (colony-forming units, a count of bacteria) or fewer, which is the drinking water standard.

How to spot it

  • A clear or white plastic bottle screwed onto the side or back of the delivery unit or chair.

What it is used for

  • Fill and treat the bottle exactly as the waterline product and unit manufacturer direct.
  • Test the water as often as the manufacturer recommends, using an in-office kit or a mail-in lab.
  • If a test fails, treat the lines per the instructions and retest right away.

Safety and care

  • Flushing alone does not remove biofilm; chemical treatment is needed.
  • Use sterile water or saline from a sterile delivery device for surgery, not the unit water.
  • During a boil-water advisory, do not use unit water for patient care.

Related

Sources: CDC. Guidelines for Infection Control in Dental Health-Care Settings, 2003. MMWR 2003;52(RR-17), ADA Oral Health Topics. Dental Unit Waterlines, CDC. Best Practices for Dental Unit Water Quality