Saliva ejectors and risk

April 1, 2011
I try to avoid asking people to jump off a bridge or stick their fingers in a light socket. I simply make it a rule not to ask people to do things that put them at risk.

by Noel Kelsch, RDHAP
[email protected]

I try to avoid asking people to jump off a bridge or stick their fingers in a light socket. I simply make it a rule not to ask people to do things that put them at risk. As I waited in a dental office recently and listened as a hygienist asked a patient repeatedly to close his lips around a saliva ejector, I wondered if that hygienist had really thought about what she was doing.

The Centers for Disease Control (CDC) has given us clear and concise directions when it comes to saliva ejectors. They frequently state that, "There is a risk 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." This backflow can include previous patients' waste material, colonized biofilm1 from the tubing, and chemicals from flushing the line.

It is this simple action when patients close their lips and form a seal around the tip of the ejector that creates a partial vacuum. That vacuum can cause suctioned fluids to be retracted into the patient's mouth. Studies have shown that gravity pulls fluid back toward the patient's mouth whenever a length of the suction tubing holding the tip is positioned above the mouth, or when a saliva ejector is used at the same time as other evacuation (high volume) equipment.2

There have not been any reported adverse health effects associated with the saliva ejector. But research from nearly two decades has shown that there is risk involved. Dental health-care personnel should be aware that backflow might occur when they use a saliva ejector, especially when the tubing is above the patient's head.

A few simple things you can do to prevent cross-contamination from a saliva ejector:

  • Do not advise patients to close their lips tightly around the tip of the saliva ejector to evacuate oral fluids.
  • Never position the suction tubing above the patient. Always have it hang below the patient's head.
  • Suction lines should be disinfected between patients.
  • Dental health care professionals should contact the manufacturer of the dental unit to review proper use and maintenance procedures, including appropriate disinfection methods.
  • Many companies have come up with products to prevent backflow, including saliva ejectors with prevention built in, or anti-backflow prevention devices for the dental unit. It is important to investigate all preventive tools.
  • Saliva ejectors are single-use items and must be disposed of after a single use.
  • Do not use low volume and high volume suction simultaneously.

Keeping patients out of harm's way means that sometimes we need to change the simple things we ask patients to do and the simple tasks we perform. These changes can help eliminate the possible risk of cross-contamination.


1. Meiller TF, DePaola LG, Kelley JI, et al., Dental unit waterlines: biofilms, disinfection and recurrence. J Am Dent Assoc. 1999; 130:65-72.

2. Barbeau J, Bokum L, Gauthier C, Prevost AP. Cross-contamination potential of saliva ejectors used in dentistry. J Hosp Infect 1998;40:303-311.

Noel Brandon Kelsch, RDHAP, is a syndicated columnist, writer, speaker, and cartoonist. She is a member of the Organization for Safety, Asepsis and Prevention, and has received many national awards. Kelsch owns her dental hygiene practice that focuses on access to care for all. She has devoted much of her 35 years in dentistry to educating people about the devastating effects of methamphetamine and drug use. She is immediate past president of the California Dental Hygienists' Association, and is on the board of directors for the Simi Valley Free Clinic.

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