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The 5 most overlooked cleaning guidelines for your ultrasonic bath

Jan. 1, 2021
The more you know about how to keep your ultrasonic cleaner running at its best, the better off your practice will be. Michelle Strange, MSDH, RDH, outlines five must-dos to make sure your ultrasonic bath is working properly.

Thoroughly and properly cleaning dental instruments and equipment is critical to patient care. Contaminated dental instruments can lead to disease in otherwise healthy individuals and leave a dental practice reeling from the aftermath.1 Prior to the use of technologically advanced cleaners, many dentists and staff had to clean their instruments by hand. This has changed with engineering controls such as the ultrasonic bath cleaner.2

The ultrasonic cleaner is without a doubt a step-up in sterilization practices and helps avoid potential cross contamination and percutaneous injuries from hand scrubbing. There is more to ultrasonic cleaning than meets the eye though; it requires more than turning the dial, listening for the vibrations, and hoping it is working.

5 things you should be doing with your ultrasonic bath

There are five things every dental practice should be doing with their ultrasonic bath to ensure that the job is being done properly every time:

Water. Yep, I am writing about water. Both the temperature and the amount of water we put into the ultrasonic machine needs to be optimal. It isn’t just a guessing game for how much you fill the tank. So, what is optimal? Well, this is where your instructions for use (IFU) will guide you. Look at the IFUs for the ultrasonic equipment and the enzymatic cleaner or detergent you use with it. Be sure to precisely follow the IFUs. It is possible to use water that is too hot, which results in denaturing the enzymatic cleaner, baking on the bioburden instead of removing it, or using an incorrect ratio of water to cleaner, which means it doesn’t work as well.

Testing. It is not enough to simply assume that the ultrasonic bath is working. You will need to test it regularly. You can do this by using a piece of lightweight aluminum foil the width of the unit and cleaning solution. With the foil vertically in the tank, hold for roughly 60 seconds. If the unit is functioning as it should, the foil will have indentations and pitting.3 There are products on the market created specifically for testing your ultrasonic bath that are worth investigating.

Run it once before use. Wait, what? That was my reaction at least. Historically, I would fill the tank, put the detergent in, and then turn the machine on when the first instruments of the day were tossed in. However, most machines will have manuals that explain this process, and it is essential to know that your ultrasonic bath should be run once without instruments. There is a degassing (to optimally disrupt the bioburden) that needs to occur before we put our instruments in the machine.

Be mindful of detergent to water ratios. As I mentioned above, if you are not using enough water to detergent, or vice versa, the tools could possibly still have bioburden on them even after they have run through a full cycle. This is an issue because it would require you to scrub your instruments, and it increases the chance of a percutaneous injury. And let’s be honest—most of us don’t have time for additional steps. We use the ultrasonic bath because it makes instrument cleaning easier and faster. If we aren’t mindful of how much water and cleaner we use, however, we could be required to perform more steps or not be able to remove the bioburden before it goes into the sterilizer, thus increasing the chance for cross contamination.

Change the solution every day. Sometimes this may need to be done multiple times a day, but at a minimum, it needs to occur every single day. If you open the lid to the ultrasonic bath and the water is murky, or you can’t even see the bottom of the tank, it is time to change the water. We put items in the bath that can be bloody, and the enzymatic cleaner we use isn’t magic. It can only work so hard before it needs a little boost or refresh, so be sure to monitor the water throughout the day and change it as needed.

The ultrasonic bath has become a helpful engineering tool in the dental industry. Cleaning and sterilization are the most critical factors in maintaining a functional dental practice that is free of infection outbreaks.4 Without sterilization, disease and infection can occur. Hand scrubbing is an effective way to clean tools, but it can lead to injuries that can put the health of your dental team at risk. The more you know about how to keep your ultrasonic cleaner running at its best, the better off your practice will be. 


1. Thurston J. Dirty dental tools put dozens at risk for disease. NECN News. NBCUniversal Media. December 8, 2016. Accessed October 7, 2020. https://www.necn.com/news/local/vermont/unsterilized-dental-equipment-patients-testing-morrisville-vermont/134704/ 

2. Ultrasonic cleaners. Fisher Scientific. Accessed October 7, 2020. https://www.fishersci.ca/ca/en/products/I9C8JVSX/ultrasonic-cleaners.html

3. From policy to practice: OSAP’s guide to the CDC guidelines (2019 edition). Organization for Safety Asepsis and Prevention. Accessed October 7, 2020. https://www.osap.org/store/ViewProduct.aspx 

4. Centers for Disease Control and Prevention. Guidelines for infection control in dental health-care settings – 2003. MMWR. 2003;52(RR-17):1-76. https://www.cdc.gov/MMWR/PDF/rr/rr5217.pdf

MICHELLE STRANGE, MSDH, RDH, has been a dental clinician since 2000 and is currently a practicing hygienist, speaker, writer, content developer, consultant, and podcast cohost for A Tale of Two Hygienists. With a master’s in dental hygiene education and a belief in lifelong learning, she hopes to continue to learn and grow within the dental profession and one day see the gap bridged between medicine and dentistry.

About the Author

Michelle Strange, MSDH, RDH, CDIPC

Michelle Strange, MSDH, RDH, CDIPC, has more than two decades of dental expertise, beginning as a dental assistant and completing her BS from the Medical University of South Carolina and her MSDH from the University of Bridgeport. She has a Certificate in Dental Infection Prevention and Control and is the owner of Level Up Infection Prevention and MichelleStrangeRDH. Strange is a practicing dental hygienist and was the cofounder of the A Tale of Two Hygienists podcast.

Updated April 14, 2023