cross contamination, dental assisting, dental hygiene, dentistry, infection control, rdh, Uncategorized

Your Evacuation Valves Most Likely Leak

I know what you’re saying, Not My Valves!  And we hope that is the case, however, there’s a very good possibility they do.  Here’s why…

Lets first ask a couple of questions to see how well maintained your office HVE and Saliva Ejector Valves are.

*How often do you disassemble the parts on the HVE and Saliva Ejector?  See image below.  Each manufacturer states you are to disassemble as part of the regular routine and then scrub each part.


*Do you lubricate the o-rings frequently?  All manufacturers state to routinely lubricate the orings.  Specific to the leading chair mfr, they state to remove the orings entirely and lubricate each routinely.

*How often are you replacing the o-rings?  Valve companies state to inspect orings often and routinely.  Most agree to replace all valve orings yearly assuming your offices are already following the above-mentioned disassembly & lubricating routine.  Not following the above routine likely means changing more frequently.

*What is the main purpose of the orings inside the evacuation valves?

  1.  Seal off the liquid debris from leaving the interior of the valve.
  2.  Provide a swivel on the valve and tailpiece coupler
  3.  Provide a smooth easy on/off rotation

With respect to your office.  Visit each room and see if the following is easy to do:

*Pull off the HVE or Saliva Ejector easily.  These are designed to connect similar to a dental handpiece.  They will click into place and should require NO force.

*Swivel at the connection.  Same applies, similar to dental handpiece designs you should have swivel ability.  Dental unit instruments were designed to work with you and not against you to reduce carpel tunnel syndrome.  Also they are designed to reduce tangling of tubings.

*Pull/push out the On/Off lever.  These are designed to push out with relative ease.  This should require very little force.

So why is our article titled “Your Evacuation Valves Most Likely Leak?”

Over the past 3 years we’ve visited 100’s of offices, spoke with countless dental professionals and continue to work with the leading infection control professionals in the industry.  We rarely see valves maintained correctly.

When orings are not maintained, they will not work properly.  Our experience is based on the following:


1.  It very rare when we offices disassemble the valves.  Our last poll consisted of a few hundred dental professionals resulting in less than 1% following the IFU (instructions for use).  Most valves we encounter are never removed off the lines and never lubricated.

2.  Many offices we visit require a pair of pliers to remove the valves.  It is a sure indicator the orings do not work.  In these situations, the orings have become dry and brittle.  Blood, saliva and other debris leak into the areas where the oring was designed to seal.  These valves most often seap (leak) out the sides.

3.  We speak to dental professionals and ask them if they have ever seen a bubble on the side of the valve during a procedure.  More often we hear YES as opposed to NO as the response.

We’ve personally viewed leaking blood, saliva, water and bubbles.  The cause for concern is where these leaks end up.  Many of the leaks end up on the patients!  To quote one RDH, “I quickly wiped the bubble off of my patients ear in horror”.

leaking valve

Finally, just because you cannot see the leak does not mean it’s not occurring.  Bubbles and blood are obvious indicators.  However, when orings are compromised and no longer function as they were designed, they will leak air and faint fluid because they will take the path least resistance when suction is on.


cross contamination, dentistry, infection control, rdh

Do you guarantee clean evacuation valves?

Disposable dental devices have come a long way in the past 10 years.  Not long ago, a disposable evacuation valve would have been unreliable in both fit and performance, not to mention prohibitively expensive.

DOVE Evacuation Valves changed all that.  These plastic valves are made in the USA in a clean-room ISO 13485 facility, guaranteed clean from contaminants.  Plastic molds are extremely accurate producing a disposable product with consistent quality and reliable standards, manufactured to assure outstanding performance in the dental office at an affordable price.


Furthermore, DOVE Valves have been evaluated by leading infection control experts; all agree our disposable valve is a cleaner and safer alternative.   Our valves were also voted by OSAP member’s at the most innovative infection control product in early 2017.

We encourage you to carefully consider what is specifically required of your dental office is to guarantee a clean, sterile evacuation valve for every patient.  As one dentist studying the situation commented, “It’s not a matter of if someone is going to get sick from a valve that was only wiped, it’s a matter of when.”

As you evaluate, consider the cleaning protocol that your staff learned in their training program, school or university.  Each teaching facility tends to instruct the student in a protocol that is biased by its orientation, for example “busy,” programs have patients that are so tightly scheduled that wiping a valve clean, the bare minimum, is reinforced.  Teaching programs, on the other hand, are constantly exploring ways to lower costs and shockingly some students never even learn that the valve can be removed!  Minimal steps may be taught, valves maintained infrequently, flushing occurring daily or even weekly.  Finally, larger universities tend to reinforce “central sterilization,” allocating the cleaning process to an outside team.  Here students may learn to flush the lines occasionally but have very little knowledge of how to remove and clean a valve, relying on outside personnel for maintenance and repair.

The below image is a typical parts room at a University.   Most students never see this side of the routine maintenance.

dental cleaning room

You might wonder why there is no industry protocol on sterilizing such an essential piece of dental equipment as an evacuation valve. especially in today’s climate of infectious disease awareness.  Shockingly, it’s not even on the radar, taking a back seat to money makers like 3D imaging, CAD CAM, etc.

Speak with each of your staff about their cleaning techniques.  You may be surprised to find that staff use different cleaning methods even within the same office, varying among rooms.  Some flush, some wipe, some are more thorough than others.  The following are various cleaning methods that we see when we visit dental offices.

#1 – wiping the exterior and flushing the lines at the end of the day

It’s important to note that wiping the exterior surfaces without scrubbing them does not remove debris.  Recent testing on 212 valve surfaces that were only wiped between patients “all failed” a ATP bacteria test.  Also flushing once a day is only considered a preventive maintenance step (like drano) and will not clean the lines for the patient.  If backflow is a concern, every line will fail a clean test.

#2 – wiping the exterior and flushing between patients

Wiping the surfaces, as in #1 above, without scrubbing, does not remove debris and consequently not all the valves will be clean.  Flushing the lines between patients is a great start, albeit rarely done, but without a backflow prevention device every line will fail.  The same applies to cleaning the interior surface of the lines.  Unless blood and debris is scrubbed and the surface sterilized contamination will still be present (see photo below of a flushed line).

interior valve after flushing

#3 – wiping the exterior and not flushing the lines, or flushing once a week or even once a month

This replicates the scenarios above.  Every week we encounter a new office that has never flushed the evacuation lines.  All the valves and lines maintained this way are not clean.


#4 – removing the valves, disassembling the parts and running them through a sterilizer.

This is actually what the manufacturers of the metal valves recommend be done between each patient.  We have found that only the VA clinics follow this recommendation.  This process, stipulated in the metal valve instruction guide, is the only process that will guarantee a clean traditional valve.  The major risks are in transporting the parts and assembly.  The downside of this method is time (approx 12 minutes per valve) and cost (over $3.00 per valve) which ranks it second to the disposable option.

In private practice we have found that when a sterilizer is used, it is only used once a day or infrequently at best.  In addition, unless the parts are scrubbed prior to sterilization, then the contaminants are merely baked on and not removed.

#5 – disposing of the valve and using a new DOVE Saliva Ejector or HVE valve for each patient

A DOVE Disposable Valve guarantees each patient a safe, clean valve.  DOVE Saliva Ejector Valves eliminate backflow.  Performance is consistent, time is negligible and cost (approx. $2) is less than frequent cleaning through a sterilizer, making this a superior choice.

While all the above cleaning methods do meet CDC minimum guidelines, only #4 (maintaining the valve frequently) and #5 (offering a disposable version) are truly worthy of our dental patient’s expectations.

Guaranteeing a clean, safe visit for your dental patients is easier and more affordable today than ever. It’s more than an option. In today’s environment, with busy offices and discriminating patients – it’s an imperative.