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Chairside Impact: Dove Dental backflow prevention

June 27, 2023
Most patients don't know that backflow is a risk when using saliva ejectors, but it's happened to 1 in 4. Can you imagine the reaction if they were better informed? Dove Dental has a few products to address this problem.

The CDC has stated that risk is involved in having patients close their lips around a saliva ejector. Backflow from low-volume saliva ejectors occurs when the pressure in the patient’s mouth is less than that in the evacuator.1 This backflow could be a delightful cocktail of the previous patient’s waste material, biofilm from the tubing and valves, and chemicals from line flushing. 

More Chairside Impact: 

A mouthful of biofilm

When patients close their mouth around the tip of the saliva ejector, it creates a partial vacuum that can cause the retraction of suctioned fluids into the patient’s mouth. While no adverse health effects have been reported (yet), the incidence of this happening is around one in four.2

Biofilm gets stuck inside metal valves, even after doing everything right, such as flushing and cleaning regularly.2 It is vital to consider that when patients close their mouths around the suction, they may get a mouthful of previously suctioned fluids.

What they don’t know won’t hurt them, right?

A busy practice might think that one in four with no adverse effects reported doesn’t amount to a concern. But what happens when patients find out? They will consider the practitioner as either:

Someone who didn’t know about backflow and its hazards

Someone who did know but didn’t care enough to educate the patient

Someone who did know but didn’t use any alternative products to prevent backflow

No matter how they perceive it, it doesn’t look good.

Prevent backflow, keep patients

Currently, Dove Dental offers a few disposable products to prevent backflow. One is the HVE (high-volume evacuation valve), and the other is a disposable saliva ejector (SE).

Dove Dental’s HVE is a one-way valve that helps prevent saliva and other bio-contaminants from escaping or entering dental lines. It is quick and easy to attach and remove. The disposable SE valve fits onto any standard dental handpiece and is made of soft vinyl materials for patient comfort. Its single-use design helps reduce cross-contamination risk and minimize cleaning time. The long-neck versions are more traditional, while the short-neck versions are the newer ones designed to sit above the dental hanger when not in use. Disposable SEs only allow for one-way suction, so there is no chance of backflow.

Replacing the metal valve eliminates the entire dismantling and cleaning process, which is handy, particularly in high-­turnover clinics. By alleviating backflow and reducing aerosol risks, clients can feel protected even if they accidentally close their mouths around the straw. It is then possible to work on the patient while letting them know that the products in use eliminate any risk of backflow, just in case they have heard about it!3

Other options

If you are waiting on Dove Dental disposable products to arrive, there are some other ways to prevent cross-contamination from saliva ejectors4:

  • Tell patients not to close their lips around the SE tip.
  • Do not position suction tubing above the patient.
  • Disinfect suction lines between patients.

Let’s invest in infection prevention tools now so we aren’t part of the next gross dental story that makes national news. 

Editor’s note: This article appeared in the June 2023 print edition of RDH magazine. Dental hygienists in North America are eligible for a complimentary print subscription. Sign up here.


  1. Saliva ejector and backflow. Centers for Disease Control and Prevention. Updated March 3, 2016. Accessed April 7, 2023.
  2. Barbeau J, ten Bokum L, Gauthier C, Prévost AP. Cross-contamination potential of saliva ejectors used in dentistry. J Hosp Infect. 1998;40(4):303-311. doi:10.1016/s0195-6701(98)90308-5
  3. Cohen S. Beware of backflow at the dentist. HuffPost. September 1, 2016. Updated December 6, 2017. Accessed April 7, 2023.
  4. Kelsch N. Saliva ejectors and risk. RDH. April 1, 2011. Accessed April 7, 2023.
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