Many of us got into the practice of dentistry because we wanted to help people. I can safely say that it was an endodontist that got me out of pain and helped me live a fuller life back when I was in college. That aspiration to help people can make it all the more frustrating when a patient comes to us in pain—and the radiographs show nothing. The tests are inconclusive. And we’re not sure what to do with our failed dental x-rays and all the possible causes of our patient’s troubles.

How do we get to the right diagnosis and right treatment plan for our patients? I’ve got some ideas.

The tale of a failed dental x-ray: A Tooth Story

This patient was a 56-year old woman, and her official diagnosis was Necrotic Pulp and Asymptomatic Apical Periodontitis (read a little more on pulpal and periapical diagnosis here).

At this point in my career, it is a quite normal occurrence to have radiographs that give me no signs of what to come. Yet despite a failed dental x-ray, or one that really shows nothing amiss at all, the patient is still in pain, just like this woman.

She was referred by her dentist after a heavy dose of pain meds and some antibiotics. By the time I saw her, she could not indicate which tooth was giving her trouble, and I had nothing to go by from the periapical radiographs. Which meant this would be a tough case. Time to put on my detective cap!

Teeth #2-5 had no pain to percussion, and the only tooth in the quadrant that felt cold was tooth #2 (#3-5 had no response to cold). I couldn’t assume that all three teeth were necrotic.  Which tooth was it? She described having a few days of excruciating pain and then it started to subside. Her claim of having a painful episode like this one is usually a sign that a nerve has died somewhere, but I knew I needed proof.

Getting an accurate diagnosis

We all know that periapical radiographs can be great, except when they’re not. What a failed dental x-ray shows or doesn’t show, combined with a heaping helping of pain, can be a nightmare for diagnosing accurately.

At this point, I was frustrated and the patient was frustrated—so I opted to employ the ol’ cone beam. I no longer have to wait for my patient’s pain to return and localize, which is a blessing for both of us!  I can see right through the buccal bone, without waiting for the bony breakdown of the cortical plate to occur. Which meant that I could treat this patient right away and get to work on relieving her pain.

I took a cone beam to see if I could determine the etiology of her pain. I looked carefully through the planes, seeking any irregularities in the teeth and any resorption of bone. Everything looked normal … until I got to tooth #3. I could see a small radiolucency around the disto-buccal and palatal roots.


You can see the thickened sinus membrane in the next image as well (green arrows). This was the sign I needed that tooth #3 was necrotic. Despite all the difficulties in getting there—from the failed dental x-ray to the patient’s spreading pain— I gave her a confident diagnosis and told her that we could proceed with treatment right away.

The ins-and-outs of CBCT

I am a very thorough tester—which counts for a whole lot! And this is a clear example of a case where the traditional methods just didn’t cut it. (I mean, compare those first radiographs to what showed up using the cone beam!)

I am embracing the technology of CBCT because it helps me accurately diagnose my patients and expedite their healing journey, especially when the dental x-rays fail and the normal tests don’t work. I know the CBCT is not foolproof (see my blog on cone beam and cracks), but it does help me diagnose cases more accurately every day, and get my job done—and that job is to save teeth!

I’d love to hear about your experiences with the CBCT. Tell me: Where has it helped you out? And where has it failed you? I want to hear your honest responses.

Leave your comments below because they will help other dentists in our group shorten the learning curve for this powerful technology!

In the meantime, I’d love to offer you my free Pulpal and Periapical Diagnosis Checklist, which can help you get to the root (haha, get it?) of your patients’ pain, every time!

– Sonia