Complete Guide to Dental Unit Waterlines

Dental unit waterlines are not likely the hottest topic floating around your dental practice. Still, understanding what waterlines are, how they can become contaminated, and how to adequately maintain them is essential to protecting your practice, team, and patients.

So, let’s jump right in. Here’s what we will cover in this article:

• What is the definition of dental unit waterlines?
• What is the difference between dental unit waterlines and dental evacuation lines?
• How does water move to and through dental unit waterlines?
• What does dental infection prevention have to do with dental unit waterlines?
• What is dental unit waterline maintenance?
• Why is waterline maintenance necessary?
• What compliance standards for dental unit waterlines should my practice follow?
• What steps does my dental office need to follow to have compliant dental unit waterlines?

What is the definition of dental unit waterlines?

In simple terms, dental unit waterlines are plastic tubing that carries water to the high-speed handpiece, air/water syringe, and ultrasonic scaler.

These lines are typically made of a polymer (e.g. polyurethane, polyvinyl chloride) plastic or silicone rubber tubing which results in a lightweight, soft, and easily maneuverable waterline. While this is perfect for moving around to get into those hard-to-reach places in your patient’s mouth, it is also the ideal home for bacteria growth.

The tubing offers a porous surface that bacteria can easily grab hold of. It’s not visible to the naked eye, but both rubber and plastic polymer has small divots that allow the material to expand and contract on demand as it is moved. Think of tires driving over a gravel road. The tires naturally grab onto the surface, but the grooves pick up rocks and sand that are small enough to wedge their way into the crevices. In essence, while the rubber tubing is great for usability, it’s not great for infection control.

Additionally, waterline tubing is incredibly small (diameter of 1/8 – 1/16 inch) and the volume of water needed per patient is minimal. This means that even when used regularly, water doesn’t move very quickly through the line. Instead, it inches forward, then sits stagnant. This becomes the perfect environment for bacteria.

What is the difference between dental unit waterlines and dental evacuation lines?

In layman’s terms, a dental unit waterline is made up of small-bore tubing (usually plastic or rubber polymer that connects to a coupler. Dental waterlines carry water to a handpiece which is usually used for daily patient treatment. An evacuation or suction line removes fluid and debris from the patient’s mouth during dental procedures.

Both waterlines and evacuation lines have their own set of treatment procedures.  Always be sure to consult the manufacturer guidelines for any piece of equipment before utilizing any maintenance products on them.

How does water move to and through dental unit waterlines?

While you may interact with water and waterlines daily, you might not have given a lot of thought about how the water that rinses your patients’ pearly whites gets there. While this may not be the most hair-raising information, it gives context to how waterlines can become contaminated and form stubborn, aggressive biofilm if not treated properly.

Knowledge is safety in the case of infection control in dentistry, so we want to guide you through the journey of water through your lines to help give you insight into where and how bacterial growth happens:

1. Water starts at the source. The source will vary depending on your practice. Water may come from bottled distilled water, bottled spring water, filter, distiller, R/O unit, tap water, or may even be plumbed directly into the chair. In many cases, bacteria is already present at the source level before it even enters your waterlines.
2. From the source, the water will journey to the chair. Whether your chair is plumped directly to the city or has an independent water reservoir the moment water enters your chair it has entered an ideal environment for growth.
3. Once the water is at the chair it travels into the junction box where a myriad of delicate tubing is not-so-delicately shoved into small spaces. This is where the waterline officially begins.
4. From there, the water travels through the waterline to a handpiece and out into your patient’s mouth. In some instances, retraction (a.k.a. your patient’s fluid being sucked back into the handpiece) can become a source of new bacteria that fight the flow of water and grows backward into the waterline… we know, gross!

All that to say, bacteria can enter your water from a plethora of different touchpoints, and it’ll do everything it can to thrive in the environment it is in.

What does dental infection prevention have to do with dental unit waterlines?

It’s important to know that all water, even your favorite bottled water, has some bacteria in it. These bacteria are generally harmless to healthy, non-immunocompromised individuals, but the challenge comes with bacteria growing from harmless single-celled organisms to a network of bacteria called biofilm. Biofilm can become a comfortable nest for pathogens, which has the potential to lead to dangerous infections. Implementing effective infection prevention protocols in waterline maintenance is essential for mitigating that risk and creating a safe environment for you and your patients.

What is dental unit waterline maintenance?

Dental unit waterline maintenance is the process of utilizing various waterline treatment and testing solutions to help remove and prevent biofilm growth in waterlines. This is necessary for everyday dental procedures, unlike surgical procedures, which must use sterile, often single-use disposable equipment. Ultimately, the goal of waterline maintenance is to ensure that safe water is being used for all procedures, routine or specialized–protecting you and your patients.

Why is waterline maintenance necessary?

In any chair, even the busiest, water sits stagnant for most of the day. This gives bacteria ample time to create thick, complex layers of biofilm. Even when the water is used, fragments of a mature biofilm will intentionally separate so it can go further down the waterline and restart the biofilm process again. So, it’s essential to recognize the potential of biofilm in your waterlines and begin to take action against it.

Though you may be using tablets (like BluTab), straws/cartridges (like BluTube), or even a centralized filtration system, rarely are these enough to keep aggressive colony-forming bacteria at bay. Your waterline maintenance protocol needs to be strong enough to fight back. For those just getting started or those looking for an effective protocol, we recommend the 3 simple steps to safe water.

But still, why is waterline maintenance necessary?

Allow us to briefly answer a question with a question. How do you know that restaurants utilize clean machinery, water, and drying techniques to sterilize their cutlery and dishes prior to you digging into your deliciously crafted Bourbon Chicken and Shrimp?

Assuming that you don’t pop into each of your favorite eatery’s dishwashing station, there is a level of trust that you are giving that restaurant by choosing to dine there.

The same goes for the patients who choose your practice. They trust that you are taking reasonable and prudent steps to ensure that they do not get infected on your watch.

So, the question is, are you?

If waterline maintenance is not a part of your compliance or patient care protocol, you may have a gap in what you intend to deliver to your patients and what you are actually delivering. Providing great quality care in dentistry starts with keeping patients safe and safety must extend to the water that goes into your patients’ bodies.

What compliance standards for dental unit waterlines should my practice follow?

As a starting point, the CDC and ADA follow the EPA regulatory standards for drinking water (less than or equal to 500 CFU/mL of heterotrophic water bacteria) for quality water in dental procedures. Keep in mind that a test resulting in 400 CFU/mL today can be over 4,000 CFU/mL tomorrow. We will keep ringing that bell, biofilm is aggressive!

As the FDA explains, “Municipal water contains microorganisms that may be considered safe for drinking water, but could potentially cause patient infections when used during dental procedures…Without proper cleaning and disinfection, waterborne microorganisms can collect in the dental unit waterline and form a biofilm, a layer of microorganisms or bacteria adhered to the surface of the dental unit waterline, that can become dislodged and enter the water stream. Contaminated dental unit waterlines pose a risk of infection to the patient, particularly during surgical procedures by direct exposure of waterborne pathogens and to dental professionals due to inhalation of aerosols.”

With many of our interactions with dental professionals we are often asked, “what does my state require me to do?” While that is a great question, we think the best question is, “what level of safety should I provide my patients so that I know with 100% certainty they are safe in my care?”

To help answer that question, we’ve simplified waterline compliance down to an effective, 3 step protocol that your practice can implement. You can download it here or keep reading to see what each step entails.

What steps does my dental office need to follow to have compliant dental unit waterlines?

With over hundreds of thousands of dental unit water data points, our team put together the Proven Protocol, an effective, simple, 3-step protocol for safe water.

The “Proven Protocol” to Waterline Compliance

The latest recommendations and research in infection prevention for dental unit waterlines show that every effective waterline maintenance protocol includes these three steps:

1. Shock: Shocking is to dental waterlines what a professional dental cleaning is to oral health–it is essential to ensure major buildup is removed and waterlines remain healthy. This step whips your dental waterlines into shape by using a strong disinfectant (like diluted bleach or Liquid Ultra) to completely rid your lines of contaminants to give them a fresh start every quarter.
2. Treat: If shocking is for dental waterlines was like a visit to the dentist’s office, treating is like daily brushing and flossing. To maintain the clean conditions made by shocking, all lines should use treatment products like straws or tablets to reduce and inhibit the re-growth of bacteria.
3. Test: This essential step helps evaluate the effectiveness of the maintenance efforts. Without testing, there is no way to know that your practice is delivering safe water to every patient. Testing also provides the documentation necessary to protect your practice if an infection is thought to be linked to your office.

Following this proven protocol will ensure that your dental waterlines are compliant. It may require some practice, but those who have successfully implemented this protocol have achieved safe water for both them and their patients.