Has Your Dental Unit Waterline Become a Bacterial Metropolis?

Everything You Need to Know to Keep Your Dental Waterlines Clean

For decades, dental professionals have known microorganisms were colonizing the waterlines of their dental units. Ample evidence shows the narrow tubing, low flow rates, and frequent stagnation periods found in water delivery systems create the ideal metropolis for biofilms. These slimy mats of bacteria cling to the walls of the plastic tubes, sloughing off countless individual organisms into the water as it passes by.

The US Centers for Disease Control and Prevention (CDC) says dental practices should use water containing no more than 500 colony forming units (CFUs) per milliliter, the maximum allowed in public drinking water by Environmental Protection Agency (EPA) standards. But when left untreated, it takes only five days for new waterlines to reach microbial counts of 200,000 CFUs/mL, the CDC says. Contamination as high as 1,000,000 CFUs/ml has been reported.

Although dental professionals have known waterlines harbor bacteria, until relatively recently there has been no solid evidence this contributes to the spread of infection. That changed in 2011 when an 82-year-old woman was diagnosed with and died from Legionnaires' disease following a dental appointment. Investigators found Legionella pneumophila on the dental handpiece waterline in the practice the woman had visited.

In 2015, a CDC report concluded that a rash of Mycobacterium abscessus odontogenic infections among children in Georgia could be traced back to contaminated water used during pulpotomies. The dental units in question, the CDC said, contained an average of 91,333 CFUs/mL.

There is no question now that dental unit waterlines can contain microorganisms well above safe levels, and these bacteria can cause deadly diseases. Cleaning and maintaining waterlines is critical for every dental office.

Fortunately, with the right tools and regular attention, preventing bacterial growth in your practice’s dental unit waterlines is possible.

Keeping Dental Unit Waterlines Clean

There are several different ways to clean and maintain dental unit waterlines, and dental practices should select the method that is most appropriate for their needs.

Water Filters

New innovations in recent years have made water filters the most convenient way to clean and maintain waterlines. The Hu-Friedy Waterline Filter continuously works to deliver clean water to patients and staff for up to a year. It features a ready-to-use cartridge that is easy to install and inhibits microbial contamination in the waterline. Once installed, the filter goes to work, requiring no daily, weekly, or monthly maintenance with minimal human interaction.

With a universal design, it can be used with either a municipal waterline or an independent water reservoir. Additionally, the filter is non-corrosive and does not contain silver or other hazardous materials, so disposal is quick and easy – just throw it in the trash.

It’s always important to note, however, that any type of filter connected to a municipal water supply will be ineffective if your town or city declares a boil-water advisory. If this happens, the CDC says, “Do not deliver water from the public water system to the patient through any dental equipment that uses the public water system.”

Chemical Treatment

There are alternative methods to waterline maintenance for practices that want to take a more hands-on approach. These alternatives apply primarily to practices that maintain their own water supplies in independent reservoirs or bottles and involve the use of chemical germicides on an ongoing basis.

Prior to maintaining waterlines, dental facilities need to clean their waterlines with an antimicrobial cleaner – often referred to as a “shock” treatment. Shock treatments are typically utilized monthly or more often if the waterlines get above the CDC recommendation of 500 CFU/mL.

Hu-Friedy’s VistaTab™ Dental Waterline Cleaner Tablets have the advantage of working fast. The tablets dissolve quickly when dropped in a water reservoir, while still being safe on your equipment. The solution will only need to sit for five minutes to purge the bacteria from waterlines, unlike others that take several hours or – even worse – multiple, hourly applications day after day.

Daily maintenance drops, such as Hu-Friedy’s VistaClean™ Irrigant Solution Concentrate, are easy to use. Just add one to five drops a day, depending on the size of the water bottle, to emulsify organic and inorganic contaminants that build up in waterlines. When used as directed these drops are environmentally friendly, non-toxic, and non-corrosive, so patients won’t taste or smell them.

Special Approaches for Surgical Procedures

Regardless of how practices maintain their waterlines, it’s important to remember that sterile water – not filtered water – should always be used for surgical procedures. Because oral surgery raises a patient’s risk of local or systemic infections, the CDC recommends the use of sterile irrigating solutions and devices designed for the delivery of sterile irrigating fluids.

Concerned About Your Waterlines?

If you’re worried about a bacterial metropolis in your dental unit waterlines, the first step is to test the water. The CDC recommends regular monitoring according to the guidelines provided by the manufacturers of your dental units or water delivery systems. Commercial testing kits and laboratories are available for this purpose.

While it can be disturbing to discover high levels of bacterial contamination in your dental unit waterlines, it is not a difficult problem to solve. An initial antimicrobial treatment followed by regular cleaning and maintenance will keep bacteria counts low.