Here… we… go! Are you ready for an endo tooth story packed with more lessons than you can shake a stick at? ‘Cause that’s what you’re getting in this tale about the merits of endodontic treatment planning.
I had this patient referred to me, and his slip indicated that the root canal I’d previously performed may have a reinfection. A more honest way of saying that is: I messed up.
Anytime that happens, my heart sinks. I mean, nobody wants their work to fail, right?
When I asked this patient what his chief complaint was, he told me that cold liquids cause him great pain. I cocked my head at this. If “cold” is his chief complaint, how can a root canaled tooth hurt him?
Lesson #1 is LISTEN to the patient’s chief complaint.
Naturally, I felt some relief, since his symptoms were evidence that the problem wasn’t my treatment, but we still had to solve the real problem. I took the preoperative radiograph so I could more closely investigate his pain.

I am not going to lie, I was a little disappointed that the referring dentist would assume there was a reinfection on tooth #18, especially since everything looked great on the radiograph. No doubt that my patient lost faith in me, and I had to spend extra time convincing him that our previous treatment was doing just fine.
As I evaluated the radiographs, I looked for teeth that could be culprits for cold sensitivity, but as I performed my tests, not much came up. All his teeth tested normal to cold except tooth #19, which had NO response to cold at all. It was slightly tender to percussion, but only ever so slightly. Baffling.



When I tested tooth #30 (it also had a crown), it tested normal to cold and then went away without any lingering pain. So, I assumed that tooth #19 was necrotic and that his nerve died, and what he was feeling was the death of that nerve. Of course, now that the nerve was dead, he’s no longer going to feel the cold that caused him pain.
His pain level was low at the time of evaluation, so I diagnosed him with Necrotic Pulp and Symptomatic Apical Periodontitis #19 and we went through endodontic treatment planning for a root canal on #19.
The patient returned for treatment.
A few days passed and he came back for his treatment appointment. My assistant brought the patient in and asked him how he was feeling. What he said next sent me reeling:
“My tooth has really been sensitive to cold lately, worse than before.”
Now hold up — what?!
So my VERY SMART assistant (that’s her in the image) reviewed his preoperative diagnosis, and saw that it said Necrotic Pulp. But that didn’t really jive with his alleged symptoms. He claimed the last time he felt a cold sensation was that same morning. So, she asked me to retest the tooth to make sure that I got the correct diagnosis. She knows that there is nothing worse than starting the wrong tooth!
Lesson #2: Always ask your patients how their tooth feels at the beginning of the appointment.
Got that? Good! Don’t skip this step! It’s super important.
And now it’s time for another lesson learned…
Lesson #3: Make sure you teach your assistants the WHY behind diagnosis so that they can have your back during endodontic treatment planning.
If it weren’t for this assistant, I may have misdiagnosed and picked the wrong tooth. Then he would still have the same pain before AND after treatment, and I would feel awful. I really hope that all of you are sharing with your team the knowledge that you learn through these blogs, and are allowing them to help you with the endodontic process. They are an asset and fully capable of learning it as well as you.
In an endo case like this, I always retest my patients prior to the anesthesia to make sure that I agree with myself. Let’s face it, nobody’s perfect! That’s Lesson #3b!! (Everybody likes a good bonus lesson.)
When I retested him, we were inconclusive. Unreal.
#19 still had no response to cold, but that was not corresponding with his chief complaint. So, even if #19 is necrotic and a problem, it is not THE problem. If he still had pain to cold once the anesthesia wore off, he would be understandably very upset, an outcome I always try to avoid, but especially in this case because he is a lawyer, haha.
So, you know what I did? I aborted the root canal. Yep, just decided “nah, we aren’t doing this.” And no, I didn’t do this because he was a lawyer. The loss of production really doesn’t matter to me — I am more concerned about getting the right tooth, and I hope that you practice endodontic treatment planning the same way. I will tell you, this act of retesting before anesthetizing is something that I do A LOT. I like to be 100% sure.
Lesson #4: Never start a root canal unless you are 100% positive of your diagnosis and that the patient’s pain is 100% localized.
It’s better to delay treatment than to assume you’re right and miss the mark.
So, when I retested his teeth, #17 was the most sensitive to cold. Now this may change his treatment plan, because I’m not sure if #15 is restorable anymore and #17 is a wisdom tooth. The patient may want to just take #17 out if that is the culprit tooth.
So how did I handle this? Well, I told him to go home and start functioning with the tooth to see what really troubles the tooth: HOT, COLD or BITING. You want to make sure that the patient does not avoid functioning on this side, make sure they use it so they can tell you what is bothering them.
Fast forward another few days — my patient’s pain got a little bit worse, and yes, cold was still his chief complaint, and it was definitely coming from #17. So, based on our radiographic findings, he has decided to determine restorability of #15 with his general dentist, and based on that decision perhaps extract tooth #15 with tooth #17.
Y’all I’m so glad I didn’t start treatment on #19 based on my original endodontic treatment planning! I am hoping that this endo case tooth story reminds you just how careful we need to be with your diagnosis. A misdiagnosis can happen to the best of us, but it’s how we handle it that really matters.
Let me know what you learned from this case! Have you taken the same missteps as I did? What will you take away from reading this tooth story?
dear dr ,excellent explanation.how did u check vitality in reln to 19 which had a crown?is it reliable?
I use the cold test every time with a cotton pellet and endo ice. The crown should really make no difference when you cold test like this.
-Sonia
Then what’s the diagnosis of #19 and did you eventually treat it?
Xiao,
No, since it was tooth #17. He got #15 and 17 extracted. At least that is how we left it when I saw him last.
-Sonia
it is nice that you also discuss your mistakes. too many ‘experts’ out there only mention their successes.
Thank you for your feedback and for reading!
-Sonia
it is nice that you talk about your mistakes and learn from them.
Hi Alvin, Thank you for reading! I appreciate your feedback.
-Sonia
Phew!! I felt I was dealing with this situation myself as you were narrating. Thank you for sharing your brains with us. It really helped!!
Thanks for reading Ravneet!
-Sonia