For whatever reason, a lot of dentists use the endo ice improperly and/or interpret the cold test results incorrectly. The end result is the wrong pulpal diagnosis for a sensitive tooth.
This is a guide on how to use this pulp vitality test to properly diagnose the health of the tooth nerve in order to determine if it needs root canal therapy.
Table of Contents:
How to cold test teeth
Cold test on teeth commonly involves using Endo Ice due to its simplicity and convenience but other types of cold mediums can be used as well.
Supplies needed:
Endo Ice
College pliers
Cotton pellet
For the cold test, you will be testing a minimum of three teeth, the tooth in question and two control teeth. The controls should be adjacent to the experimental tooth or at least in the same quadrant as it.
Below is how you test a single tooth and you will need to repeat it for all three teeth.
How to do it:
Hold cotton pellet with college pliers.
Spray it with endo ice for 2-3 seconds.
Apply the cold cotton pellet to tooth.
Remove cold from tooth as soon as the patient feels it.
Record the response.
What to watch out for: Make sure your cotton pellet isn't so big that it touches adjacent teeth.
Recording cold test response
There are 3 pieces of information you can obtain from cold testing a tooth.
Does it feel the cold?
How long does it take to feel the cold?
How long does the cold linger?
The information from all three of those questions will help you in formulating a diagnosis for said tooth based on the severity of its cold sensitivity.
Why test 3 teeth?
At a bare minimum, the cold test must be done on at least 3 teeth because this vitality test provides relative results rather than absolute results.
If you don't have a control tooth, you won't know if the tooth in question is showing pathological symptoms or not.
The more control teeth that you use, the more accurate or confident you can be in your diagnosis.
The control teeth provide information for how "normal" teeth should respond to the cold.
If the questionable tooth responds with a large deviation to the control, it may be pathological. However, if it responds within a close range of the control, it may not necessarily be diseased.
Cotton pellet vs Cotton tip applicator
Due to convenience, a lot of clinicians use the cotton tip applicator (q-tip) rather than a cotton pellet but that is less effective.
The pellet of cotton is more effective because it contains a larger volume of cotton so it retains the endo ice better. Using it will invoke a stronger cold response from the tooth.
The cotton tip applicator is convenient to use but it contains less cotton so it does not retain the cold as well. Using it often invokes a weaker or more muted cold response from teeth.
Pulpal diagnosis with cold test
The purpose of using a cold test on teeth is to obtain a pulpal diagnosis, which tells you the health status of the tooth nerve. Put another way, it is a pulp vitality test.
The diagnosis in turn will tell you what the next step is because there is an associated treatment with each diagnosis. In other words, the endo ice test gives you clues as to whether a root canal is needed or some other type of dental treatment needed.
Pulp Diagnosis | Treatment |
|---|---|
Normal pulp | No treatment |
Irreversible pulpitis | Root canal |
Reversible pulpitis | Restorative treatment |
Necrotic pulp | Root canal |
In the next section we will explain how to interpret the cold test results to arrive at each diagnosis, the signs and symptoms.
Normal pulp
A tooth nerve that tests normal to cold does not require any treatment whatsoever.
Cold test response:
Able to feel it.
Cold sensation felt within 3 seconds.
No lingering afterwards.
Overall the cold doesn't really seem to bother them too much. The tooth will react similarly to other teeth in the mouth.
Irreversible pulpitis
A tooth nerve with irreversible pulpitis has progressed beyond the point of recovery and will need a root canal. As it's name implies it cannot reverse its unhealthy state back to normal.
Cold test response:
Able to feel it.
Cold sensation felt within 3 seconds.
Long lingering sensation afterwards.
This condition often responds with the most exaggerated response to the endo ice.
The patient may feel a very sharp pain.
They may want to reach towards the ceiling.
It could even give them a headache for a few minutes after the pulp test.
Reversible pulpitis
A tooth with reversible pulpitis can recover and revert back to normal. Typically there is a condition which is causing it to be symptomatic but as long as you treat it, it should heal.
Cold test response:
Able to feel it.
Cold sensation felt within 3 seconds.
Slight lingering afterwards.
Conditions causing reversible pulpitis:
Recent dental treatment.
Tooth decay.
Gum recession.
Tooth concussion.
This condition is the best example of a cold sensitive tooth that doesn't need root canal.
Necrotic pulp
A necrotic pulp is a tooth nerve which has died. Yes, you've a dead tooth if it is no longer responsive to all types of vitality test.
Cold test response:
Unable to feel the cold at all.
Does not respond to temperature.
For a non-vital tooth, a root canal is recommended because it removes the dead nerve and it also opens up the opportunity to internally bleach the tooth later on.
It's a test of relativity
The most important concept to understand about the cold test is that it is a test of relativity.
The results (responses to cold) are NOT meaningful nor are they significant on their own. They require responses from control teeth in order to provide context for the results of the tooth in question. Otherwise, it doesn't mean anything.
Examples of nondiagnostic tests:
If none of the teeth feel the cold, it doesn't mean that all the teeth are necrotic.
A 5 second delayed response to cold doesn't mean anything if all of the teeth test similarly.
The point that we're trying to make is that everyone will respond to stimuli differently. What you want to obtain from a cold test is what is normal for the patient. Then you go ahead and test the tooth in question to see how it compares to normal.
For some reason, everyone seems to miss that above point.
