7042 S Revere Pkwy #400, Centennial, CO 80112

How To Shock Your Dental Unit Waterlines

Dental waterlines are extremely susceptible to bacterial contamination. Why that’s the case is another conversation altogether, but because of that, they must be treated consistently and effectively.

The kinds of treatment options can be split into two categories – shock treatments and continuous treatments. Shock treatments contain high-level disinfecting agents meant to “shock” the system and eradicate all biofilm. Continuous treatments contain a low-level anti-microbial making them safe for contact and undetectable to patients.

Shock treatments work okay by themselves, continuous treatments work a bit better by themselves, but when you utilize them together, that is the most effective protocol for dental practices.

Shocking essentially get your lines to “0”, while continuous treatments keep them that way for a longer period of time.

Our lab works with thousands of offices across North America and it doesn’t matter what treatment product they’re using, effective shocking is a necessary step to consistently passing waterline safety tests.


When To Shock Your Dental Waterlines?

Using a Continuous Waterline Treatment

Shock Before Initial Use of a Water Treatment ProductAs mentioned above, continuous water treatment products like tablets, drops, and straws effectively maintain already clean dental waterlines. Shock your dental unit waterlines prior to treatment to clear out biofilm and ensure that your treatments can do their job and protect your patients.

Shock Every 1-3 MonthsThe best products recommend shocking your dental unit waterlines between 1-3 months. Effective resistance against microbial growth slowly diminishes within this timeframe and biofilm counts can quickly rise towards the 500 CFU/mL limit. You'll definitely hear from some product reps that shocking isn't necessary with certain products. We've not found this to be proven in practice (take a look at the data or get the 12-page peer-reviewed E-Book by Nancy Dewhirst, RDH and John A. Molinari, Phd.) and recommend testing your waterlines to make sure your product is performing as advertised.

Shocking your dental waterlines consistently purges out the regrown bacteria, restores a clean environment for continuous treatment, and ensures safe dental water.

USING Only A Shock Treatment Product

Shock Every Week - Without using any dental water treatment products designed to be in your waterlines continuously, biofilm can re-attach and begin growth immediately after shocking your waterlines. Studies have shown that within 5 days, bacteria counts can grow to 200,000 CFU/mL (Barbeau J., 1996).

This method of maintenance requires consistent attention, and shocking less than once a week can put your patients and practice at risk. Test your waterlines regularly to make sure your protocol is being effective.

Regardless of your Protocol, Shock When Your Waterline Test Reveals Microbial Counts of 200 CFU/ML or Above

Biofilm never quits. These colonies are highly organized and attach, multiply, and spread very efficiently. They are also constantly receiving reinforcements as water enters the line. The more there are, the more effectively they can spread.

Because of this, when your test reveals a line at 200 CFU/mL or above, we recommend shocking to ensure these colonies cannot quickly multiply and exceed the ≤ 500 CFU/mL guideline.

If a line is between 200 CFU/mL and 500 CFU/mL, shock within 7 days, continue regular treatment and testing. If a line is at 501 CFU/mL or more, shock immediately and retest to make sure lines return to below the CDC guideline (≤ 500 CFU/mL).

The only way to know when biofilm levels reaches 200 CFU/mL is consistent dental waterline testing.


How To Shock Your Dental Waterlines

Always check manufacturer’s instructions for your operatory equipment and shock product. Different chair manufactures suggest different shock protocols and different treatment products call for different techniques and frequencies.

Our water safety specialist team has found using diluted bleach for a maximum of 10 minutes or Liquid Ultra (formerly Sterilex Liquid Ultra) following their overnight directions to be most effective.

 Blue Line


DOWNLOAD Shocking With Bleach Protocol HERE:


Download Your Protocol


Blue Line

There are many other shock products available, however, many of our customers have found them too inconsistent or weak in real-world practice. With shocking, you want to only have to do the process once at the recommended intervals rather than 3 or 4 times.


When your continuous treatment is a straw or cartridge, do not shock through your straw (Using Citrisil shock with Sterisil Straw is the only exception). Shocking through a straw can permanently damage it and leave it completely ineffective.

Request a “shock straw” or "dummy straw" from the manufacturer or request one from ProEdge - a little freebie - and remove your straw before shocking. Then, use these instructions for to shock your lines with the straw provided. 


If you're using an in-line cartridge or system for city-water hookups, there is often no easy way to shock your waterlines. Yet, these products can fail like all the others.

If testing has revealed the need to shock your waterlines, we recommend the following:

Blue Line



Blue Line   

How Do I Know What Kind of Shocking is Best For My Practice?

Each practice has its own unique preferences and requirements, but the important part is that your treatment protocol is effective. No point going to all that trouble if it does not meet the goal you're trying to reach. Do your product research and always test your waterlines to ensure they're meeting the safe water guidelines of ≤ 500 CFU/mL set by the Center for Disease Control.

Our ProEdge Water Expert team is always ready to help you answer this question. With 15 years of experience helping professionals achieve safe dental waterlines, we can help you shock regardless of what dental water treatment products you are using.

Blue Line




Download Your Protocol


Blue Line

If you have other questions about shocking your waterlines, contact our safe water specialists today.


*Barbeau J., Tanguay R., Faucher E., Avezard C., Trudel L., Cote L., Prevost AP. Appl Environ Microbial 1996; 62:3954-9.




Tags: dental unit waterlines, dental unit waterline maintenance, Shocking Your Waterlines