December 11, 2023

The Truth About Distilled Water

Myth: I don’t need to test or treat the water in my dental chair because we use distilled water.

Reality: False, let’s bust this myth!

While distilling does rid water of impurities and removes 99.9% of the contaminants in your water, it is critical to remember that your dental unit is NOT sterile. Meaning the moment distilled water is inside your waterlines it is now a conducive environment for bacteria to grow and form biofilm. Distilled water can and in many cases has created a false sense of security. Believing that what goes into your waterlines (distilled, sterile water) is what is coming out.

A study conducted by Barbeau confirmed that bacteria can overwhelm brand-new waterlines even when using sterile water. The resulting CFU count after 5 days of using sterile water in untreated, brand-new waterlines revealed over 200,000 CFU/mL1… to put that in perspective the EPA and CDC consider 500 CFU/mL to be safe for consumption2. That’s 400x the safe level for water.

Here’s the truth. While your water is going in clean, it is not coming out clean. Your waterlines are a perfect environment for bacteria to grow. Here’s a quick rundown of why that is:

  1. Tiny porous tubing (perfect for bacteria to nestle in and build a home)
  2. Long periods of stagnation (gives bacteria a chance to grow and populate uninterrupted)
  3. The infrequent, gentle water flow allows bacteria to detach and spread down the line.

It is important that even when using distilled water, you are regularly treating and testing your dental unit waterlines. In order to keep water safe for both you and your patients, a protocol that involves shocking, treating, and testing should be implemented. Here are a few resources on what a simple, effective protocol should look like:

Complete Guide to Dental Unit Waterlines

Dental Waterline Maintenance Protocol – Three Steps to Safe Water

Additionally, our safe water team is here to help you achieve safe water, you can reach out to them here or 888.843.3343.

Lastly, and something you may want to consider, your chair manufacturer may also have some concerns about using distilled water with their equipment.

When the dissolved minerals are removed to make distilled water, more carbon dioxide dissolves in the water, which produces carbonic acid. This lowers the pH of the water, making it slightly acidic, and can negatively interact with the components in the chair. Some dental unit manufacturers, including A-dec, do not recommend distilled water for use in dental units. So check your chair manufacturer’s instructions for use to prolong the life of your equipment and protect your warranty.

Bottom line: Distilled water going in does not equal safe water coming out.

1 Barbeau, J., Tanguay, R., Faucher, E., Avezard, C., Trudel, L., Côté, L., & Prévost, A. P. (1996). Multiparametric analysis of waterline contamination in dental units. Applied and environmental microbiology62(11), 3954–3959.
2 Centers for Disease Control and Prevention. Guidelines for Infection Control in Dental Health-Care Settings — 2003. MMWR 2003;52

back to blog

Publish Date:

December 11, 2023


Suggested for You