Today, I want to share a special tooth story with you. My patient was diagnosed with symptomatic apical periodontitis after experiencing PCO (Pulp Canal Obliteration). Her PCO was as a consequence of dental trauma from years ago.

I took a chance on this case, but it was an educated one. I want to walk you through my diagnosis process, how I communicated with the patient, what happened during treatment, and what I learned from this tooth story.

First step: diagnosis.

Let’s start by taking a look at my patient’s radiograph.

My client was a young lady who had experienced trauma about 8 years prior, when she was hit in the face with a ball.

She was tough! At the time, she brushed off the injury because she didn’t have any pain. But now, she was REALLY in pain.

She came to my office because tooth #8 was now symptomatic and hurt when she touched it. Her mom told me that they had always gone to the dentist regularly, and this whole time their clinicians had never mentioned that there was a problem with her daughter’s tooth.

Of course, you know me! It was time to diagnose what exactly was going on in this patient’s mouth. Teeth #8 and 9 had no response to cold, and only tooth #8 was tender to percussion. From that information, I was able to diagnose tooth #8 with a Necrotic Pulp and Symptomatic Apical Periodontitis.  

Bye bye, canal space.

When you look at the radiographs, you see that both teeth #8 and 9 have no more canal space. The canal space is completely obliterated as a result of the trauma. 

See, after trauma like hers, two things can happen. Either the pulps can go necrotic, or the pulps will obliterate. In this case, she got both.

Sometimes when I take a CBCT it shows me a different story, but in this case her scan confirmed the obliteration. Check it out. This is tooth #8 in the coronal view…

Symptomatic Apical Periodontitis and PCO

And this is tooth #9 in the coronal view…

Treating Symptomatic Apical Periodontitis and PCO (Pulp Canal Obliteration)

You can see that #8 has a PARL, but #9 does not. And the axial view did not make me feel that this was going to be a slam dunk. 

And neither did the sagittal view…

Oof. There were no canals in either of these teeth, but luckily, I only needed to treat #8.  

Patient communication is key.

With my diagnosis of symptomatic apical periodontitis confirmed, I began my conversation with the patient and her mom.  I told them I could attempt the root canal, but if I could not find a canal or negotiate it to working length, then she would become a candidate for surgery (an apicoectomy). 

I also gave the patient the option to go straight to the surgery. 

When there is a lesion like this, though, that is not my favorite option. That’s because the entire tooth is necrotic, but I would only be treating the last 5-6 mm of the root with surgery.  I just don’t feel like that is a long-term fix.

So, in this case, I went with my gut.  I always believe that if there IS a lesion, then there IS a canal. And together with the patient, we decided to try the root canal first.  And man, am I glad that we did.

Onward to treatment.

Despite my lack of assurance about how this case would go, I began treatment.

And… I was able to find the canal with an itty bitty 6 file and get to patency. Yay!

We all did the happy dance when we saw that file in the canal!! I was able to keep it conservative and finish the case.

And the best part is that there is no more talk about needing surgery!!

What could have made this symptomatic apical periodontitis case easier?

Well, taking follow-up radiographs after a traumatic incident is #1!!! 

If you have a patient like this and start to see changes in the canal space, then you can intervene earlier when the canal is bigger and wider, and the risk of perforation or file separation is lessened.  

Did you know that in cases of PCO only about 15% of the cases will go necrotic?

It’s kind of neat that, in this case, only one of the two teeth with PCO actually went necrotic.  

In cases like these with PCO, you may run into diagnostic dilemmas, and you may have to make a decision on what to do. Do you treat it with a root canal before necrosis or wait for necrosis and possible obliteration?

This is definitely a debate in the endo world, since a 15% necrosis rate is small. So, keep this statistic in mind, because it may come in handy one day!

Don’t forget to follow up with your patients regularly for years after any traumatic incident to catch these things early.

And involve them in the decision-making process! So many patients are intimidated about asking questions, but you can empower them to make the best decisions for their oral health.

What were your biggest takeaways from this tooth story? Tell me in the comments!

Empower Yourself,


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