Oral Health Group

Thermal Testing in Endodontics: Materials and Methods

March 1, 2005
by Rich Mounce, DDS

I rely upon cold as my primary objective test to determine if, when and where treatment is needed for an irreversibly inflamed pulp as well as to help determine pulp vitality. While the method is somewhat crude, cold testing is highly effective and easily employed. Only rarely do I find it necessary to employ thermal testing to hot, with or without concomitant cold testing. In practical application, cold testing, more than any other single test, allows the clinician to “zero in” on the source of the pulpal inflammation and/or confirm the diagnosis of a necrotic pulp.

For example, if the patient reports that they have pain to cold on the lower right and that the symptoms have been getting more frequent and intense and/or that they cannot drink cold on that side, my question to the patient will be, 1) “Is the pain localized?” followed by 2) “Does the pain linger to cold and/or hot?” and 3) “Is the sensitivity to cold causing you to not drink cold beverages on that side?” The patient’s response to these questions combined with objective cold testing is generally diagnostic.


The pain’s localization simply acts as a guide to the likely source of pain and if the patient’s symptoms can be reproduced, the offender has been found. Conversely, if the suspected offending tooth does not give results to cold testing, which match the patient’s chief complaint, it is very possible that another tooth is causing the symptoms (the pain might be referred) and caution is advised. In the most general terms, if the patient has pain that lingers to cold, especially for more than a few seconds, it is a virtual certainty that they have an inflamed pulp that requires treatment. If the patient cannot drink cold on the side, the patient needs a root canal and cold testing can be invaluable to locate the tooth that needs treatment.

I favour the use of Endo Ice by Coltene/Whaledent that is sprayed from a can. The can expresses a refrigerant that is dispensed onto a cotton pellet and applied to every tooth in the quadrant of concern as well as the contra lateral tooth. In actual practice, the cotton pellet is soaked with Endo Ice and allowed to cool for just a second or two to allow any wet refrigerant to dissipate so as not to drip on the patient. The Endo Ice is sprayed away from the patient’s face and carried into the mouth on the cotton pellet help by cotton pliers. Each tooth in the affected quadrant is tested reapplying the Endo Ice for each tooth. The soaked pellet is placed on the occlusal or buccal surface of every tooth one time and when the patient has any perception of any kind the pellet is removed. The tooth that is suspected is the last tooth always to be tested. Other methods of cold application are possible as are other products, but of the many methods I have tried, this product over the years has proven the most convenient.

If the patient has similar perceptions on all teeth and the suspected tooth responds identically to the other control teeth, caution is advised. Such a scenario could easily mean that either the offending tooth is in the opposing arch or some other entity aside from an irreversible pulpitis. Usually, cold applied to the offending tooth will bring a lasting and sustained response that lingers or a very sharp response that goes away quickly, in any event, a response which is significantly different (in line with the response above) from the other teeth all things being equal indicates pulpal disease and the indication for root canal treatment.

As an aside, I use the Elements diagnostic unit from SybronEndo (Orange, CA, USA) as my electronic apex locator. The Elements Diagnostic Unit has a built in electric pulp tester (EPT) if I wish to augment my cold testing with EPT.

One additional note needs to be made about patients who arrive with a mug of ice water and who require drinking the water at regular intervals to keep their pain away. Such patients virtually always need treatment. To confirm the diagnosis, allow the patient to experience the pain momentarily and move from tooth to tooth with cold to see which tooth becomes asymptomatic with the application of cold. This test is virtually diagnostic.

I welcome your feedback and questions.

Dr. Mounce is in private endodontic practice in Portland, OR.

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3 Comments » for Thermal Testing in Endodontics: Materials and Methods
  1. John says:

    Have there been any studies to determine how many patients who have the Endo Ice test on perfectly healthy teeth go on to require root canal or extraction down the road, compared to those who require the aforementioned but never had the Endo Ice test?

    Same for air or ice tests.

  2. Char says:

    Having dull ache on left side, little headache too. Dentist sprayed endo (cold) on top of one tooth with some response. Then sprayed the last tooth on top with huge pain response. Suggested crown but not decisive.
    This tooth has old silver with 2 cracks. Is it likely this is causing my daily discomfort?
    She also suggested maybe sinus problem.

  3. Do you consider the cold test to be a definitive diagnosis for irreversible pulpitis, and therefore RCT, or rather a helpful guide in consideration, along with other diagnostics as well as the history of the specific tooth, in determining if that tooth requires RCT? Thank You!

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