The Risk of Saliva Ejector Backflow and Evacuation Valve Leakage:

Saliva Ejector Backflow:

Research and the CDC point to the Saliva Ejector (smaller suction used for saliva and liquids).  Specifically the CDC states:  

Backflow occurs when previously suctioned fluids present in the suction tubing flow back into the patient’s mouth. Backflow can occur when:

  • There is pressure in a patient’s mouth (a result of closing their  lips and forming a seal around the tip of the ejector) that is less than  in the saliva ejector (similar to how liquid flows back into a cup  after drinking through a straw).
  • The suction tubing attached to the ejector is positioned above the patient's mouth.
  • A saliva ejector is used at the same time as other evacuation (high-volume) equipment.

Although no adverse health effects associated with the saliva ejector  have been reported, dental health care personnel (DHCP) should be aware  that backflow could occur when they use a saliva ejector. DHCP should  not advise patients to close their lips tightly around the tip of the  saliva ejector to evacuate oral fluids. DHCP should contact the  manufacturer of the dental unit to review proper use and maintenance  procedures, including appropriate cleaning and disinfection methods.

Evacuation Valve Leakage:

Evacuation valves (HVE and Saliva Ejector) contain multiple parts requiring routine cleaning and inspection.

Specifically, rubber or silicon o-rings are used to seal liquids during suction transfer.  Manufacturers recommend routine inspection, cleaning and lubrication of o-ring surfaces.  Rubber based o-rings have a shelf life effected by storage conditions and or chemicals used on the surfaces.  Effectiveness is also dependent on clean surfaces to assure sealability.  O-ring properties are effected by usage of dental cleaning agents that cause drying or swelling of surface.  O-rings are recommended to be discarded yearly by dental manufacturers.  

Research concludes dental offices do not inspect, change or clean o-rings.  Connection surfaces become compromised resulting in leaking either by seepage or bubbling of saliva and liquids.  For more information click here.

The following list overviews the leading Metal Valve Manufacturer Cleaning Recommendations and Frequency from each IFU (Instructions for Use):