Why You Must Perform a Cold Test on Teeth

Somebody give me a microphone, because I’m about to get on my soapbox! I recently had a conversation with a general dentist who I love, but something she said made me nearly fall out of my chair. She told me she never does a cold test. This is endodontic blasphemy! It’s so important for you to perform a cold test on teeth, and I want to tell you why today. I hope that when you finish reading this blog, you’ll feel as strongly as I do about this.

Performing a Cold Test on a Tooth: Why It Is NOT Optional

First of all, let’s talk about what cold testing in dentistry is actually for. Rather than an optional step, a cold test is an essential part of your endodontic evaluation that helps you make and understand your diagnosis. Why does this matter? Because accurately diagnosing your patient’s pain is always necessary, whether you intend on doing the root canal or not. Diagnosis is endodontics too, and this fact is not appreciated enough!

(Get your diagnosis right every time with my free Pulpal & Periapical Diagnosis Checklist!)

Think about your diagnosis like a roadmap that helps guide your treatment plan. With the right diagnosis, you can properly anesthetize, medicate, treat, and follow up with your patient. Or, if you won’t be treating your patient yourself, you can guide them through the referral process. Either way, you end up with the best possible outcome and are able to build a strong, trusting relationship that lasts for years to come.

On the other hand, forgoing a tooth cold test can lead to disastrous consequences. Without a proper endodontic evaluation—which a cold test is absolutely a part of—you can end up misdiagnosing your patient, leading to numerous potential repercussions, like:

• Performing an unnecessary root canal
• Misunderstanding your root canal and what’s normal in the follow-up period
• Extracting a tooth when you don’t need to
• Missing pathology that needs to be biopsied
• Referring your patient to the wrong specialist because the lesion is of periodontal origin
• Damaging specialists’ trust in you as a capable provider
• Damaging your patient’s trust in you—and dentistry as a whole—when they receive conflicting opinions about their treatment
• Losing your patient’s business
• Getting negative online reviews that impact your business
• Getting reported to the board

This is why I always say cold testing isn’t just for endodontists—it’s for ALL dental providers. Period.

Still not convinced about the importance of doing a cold test on every tooth you treat? Let’s have a look at a few examples that come from my very own practice.

Tooth Story 1: Cold Test on Tooth Without Pain

What do you do when you see a Texas-sized lesion that encompasses multiple teeth? Which tooth is the culprit? Do you treat all the teeth, or do you believe that none of these teeth are no longer saveable? (I really hope it’s not the latter. Please, give teeth a chance!)

You do your tooth cold test, of course! It’s the best way to ensure you get the right diagnosis and treatment plan. After doing my full endodontic evaluation, my findings were as follows:

All probings in the quadrant were within normal limits. There was no pain to percussion. In fact, the patient had no pain at all. Teeth #3, 4, and 5 all responded normally to cold, but tooth #2 did not respond to cold at all. Aha, that’s some good information! So, my diagnosis was Necrotic Pulp and Asymptomatic Apical Periodontitis #2.

Knowing that all the other teeth in the quadrant were vital, I knew that this lesion belonged solely to tooth #2. It was the culprit, and the other teeth were fine for now.

So, I created a treatment plan that included a root canal on #2, and we will see what happens from there. Hopefully, he won’t need any other treatment beyond that, but I always prepare my patients who present like this for a possible surgery, since this could be a cyst. The plan is to follow up with him in 6 months and see if this lesion shrinks.

Tooth Story 2: Lesion Present, but Teeth Test Vital

What do you do when you see a lesion, but then the teeth test vital? (Hint: You will only know if you do a cold test on the teeth!) 

Here is another patient who could literally be the previous patient’s twin when it comes to their tooth stories, but there is one key difference. This second patient presented with a large lesion around teeth #14 and 15. He was asymptomatic, had no pain to percussion, and all his probings were within normal limits. The point of departure? This time, both teeth responded normal to cold, and #14 and 15 were vital.

When I did a cold test on the teeth, I was very surprised to see that both teeth #14 and 15 were vital. My assistant even looked at me with big eyes. 

This lesion is NOT of endodontic origin, and so that means that it needs to be biopsied. I couldn’t tell you if this was an odontogenic keratocyst or metastatic cancer, but this patient needs to be seen by an oral surgeon, not an endodontist.

Do you see how a simple cold test can save patients so much money and time? Not to mention, it will build trust in you for making the proper referral! There was no need for this patient to walk through my door for this evaluation. Instead, they needed OMFS, stat!

Tooth Story 3: Different Variations of Normal

One of my referring dentists sent me this image with no other info and asked me what I would do.

What other information do you think I might need in addition to this radiograph? Maybe a history of previous trauma, some percussion test, or you guessed it—a tooth cold test? That’s exactly what I asked about!  

So I reached out to the dentist to find out if the teeth responded to cold. He replied that, yes, they do. Then I asked him if this was an African American female in her 40s. He messaged me back and said, “Yes, it is! She’s 42!”

Well, knowing that, I can make the differential diagnosis that this patient could have Periapical Cemental Dysplasia, since I learned in dental school that this happens more commonly in this specific population.

I told the referring dentist that if he feels comfortable, he should get a second peek at this patient before sending her to an oral surgeon, as an endodontist is not the right specialist for her case. Do you see how this can save your patients loads of money and time? And then guess what? That means they will have more money to spend on that crown on another tooth you so desperately want them to get. 

Tooth Story 4: Swelling and a Vital Tooth

I’m eager to share this tooth story, because it really might not be obvious to everyone. This patient was swollen in the submandibular area, and it was getting serious. She was honestly on her way to having a Ludwig’s angina. She really didn’t have time to waste seeing multiple providers to get the right answer—in fact, she would be hospitalized before long if she wasn’t treated.

So I started with a diagnosis. As I did my testing, I found that all the teeth in the quadrant tested vital. I was so confused because anytime I see swelling, I always think it’s of endodontic origin. And if it is, the thing to look for is a necrotic tooth.

In this case, I even felt that my testing wasn’t right. Why was she still feeling cold? I didn’t trust myself, so I had my colleague come into the room to re-test and check behind me. Guess what? He obtained the same result; those teeth were vital!

I took a CBCT and found a radiolucent area lingual to tooth #18.

But the CBCT didn’t show me any pathology in the periapical area.

It was all coronal, as you can see on this coronal slice of the tooth.

I determined that this tooth could either be cracked, have a periodontal issue, or be something else. So once again, I referred the patient to an oral surgeon.

Endo Ice: Your Cold Test BFF

I hope by this point, I’ve succeeded at convincing you that cold testing in dentistry is absolutely essential. But how should you go about it? Here’s a pro tip: Test with endo ice! Endo ice is your BFF when it comes to your cold testing. In fact, if your patient is in pain, you simply CANNOT go without it. 

So, let’s talk about exactly how to use it for the best results.

Tip #1: Don’t EVER use a cotton applicator for your endo ice test!

Why? Because if you do, you will never elicit a real cold response during your test. Cotton applicators produce false test results almost every single time. Therefore, instead of telling you which teeth are vital, you end up believing that all of them are necrotic! Not good.

Instead, I want you to use a simple cotton pellet on a college plier.

Cotton pellets have more surface area than a cotton applicator, meaning they transfer the cold better. This makes them more effective at getting the job done when it comes to performing a cold test on a tooth, ultimately giving you WAY better information about where your patient’s pain is coming from.

But it goes deeper than that, which leads me to… 

Tip #2: You need to feel your cotton pellet!

Yep, actually feel it with your fingers! This is to make sure it has some give and isn’t too hard, The ones that are super hard don’t hold cold well and could therefore skew your results. Oh, and one more thing:

Tip #3: Make sure that cotton pellet gets SUPER saturated with that cold spray, like in this video:

Remember, it’s not just about doing the cold test—it’s about doing it well, and paying attention to small but impactful details like these is key. 

Cold Test on Teeth to the Rescue

If there’s one thing I hope you take away from this blog, it’s this: When you design your treatment plan based only on the radiograph, and you don’t truly understand what is happening to the patient and the etiology of the problem, you can make a major mistake. 

While you might think it’s okay to not know how to properly do or interpret a cold test because you don’t do oral surgery or endodontics in your practice, the truth is that EVERYONE needs this knowledge. Because—whether you do the root canal yourself or not—you have to get that patient to a provider who can help them.

So, please, do your cold testing! Your patients will thank you. The specialists you refer to will thank you. Your practice’s bottom line will thank you.

Take Your Endo Knowledge to the Next Level with E-School LIVE

Let’s be honest—there are some details and advanced skills that dental school doesn’t have time to cover, no matter how excellent a program is. And whether or not you officially “do endo” in your practice, you’re using endodontic knowledge every day. This stuff is SO important. 

That’s why I invite you to apply for E-School LIVE, my 4-day live, hands-on endodontic CE course, where you’ll perform root canals on real patients with me there to help guide you in real-time.

I would love nothing more than to be your endodontic coach, so you can learn directly from me and become more confident in your endodontic skills. As a bonus, your knowledge will help you make your practice more profitable and your career brighter than ever!

– Sonia