Treating a tooth with a lateral canal is no easy feat. These bad boys can be tough because it’s not like you can usually see them. So I want to talk to you today from an endo perspective about how I approach this type of case and why, more often than not, I opt for a GentleWave root canal. Especially for tricky cases like this!

No one wants a root canal failure. And unfortunately, there’s no one type of tooth or canal that you really have to look out for. Every root canal presents a different kind of challenge. But I do find that one of the most underestimated cases is when a tooth has a lateral canal.

These have the potential to go south. So you might be thinking “But why? And what do I do about it?” I’ve got your answers here.

Teeth with Lateral Canals: Small Canals, Big Impact

When it comes to addressing problematic teeth, we need to think outside of the box. Sure, you may want to go with an easy excuse that gets you out of some extra work, saying that it must have been a crack or a missed canal … but what if it was a lateral canal? It’s so important to keep this as a potential etiology in the back of your mind.

If you’ve spaced on it, you’re not alone. Even I forget about this little guy all the time, and it often stumps me in my diagnosis until I have a eureka moment and the sudden realization washes over me, “OH! This tooth must have a lateral canal!”

So let’s talk candidly about this devious root canal complication. I want to walk you through one of my cases from not so long ago that demonstrates exactly how tricky they can be. Plus, I’ll discuss what you can do to treat this type of tooth competently and confidently! 

Let’s start with the preoperative radiographs.

Investigating the Case

Get a good look at the image above. When I first examined the radiographs, I thought tooth #3 should have been the problem. #2 looked like it was in good shape on the radiograph, but this patient had pain to percussion on #2, which made me scratch my head a little. That said, I diagnosed her with Previously Treated Tooth and Symptomatic Apical Periodontitis #2.

Time to get a crystal-clear picture of what’s going on with my CBCT.

Hmm. Even after the CBCT, I still felt like the culprit tooth should have been tooth #3. This axial slice shows me that all the canals appear to have been found and obturated in tooth #2, but there was a potential for a missed MB2 in tooth #3. Strange. I was really thrown through a loop when I observed that it was #2 that was bothering her, and she was very localized to the percussion test on tooth #2.

What the heck?

So I looked deeper into the CBCT, and here’s what I found:

I found this furcation breakdown and … I didn’t know what it meant. Not at first. Was it a sign of a crack? Was the root canal just recontaminated? Or was there a separate periodontal issue superimposed onto this root canal? I was stumped!

Luckily, the patient was highly motivated to save her tooth (kudos to her!). She BEGGED me to retreat the tooth, and since sometimes we just don’t know until we try, I moved forward with the procedure.

Those Sneaky Lateral Canals

My root canal doesn’t look much different from the pre-op except for one minor difference.

Can you spot it?

A tiny lateral canal in the tooth is radiating from the MB root that leads right into that furcal breakdown.

Now, I need to give a little disclaimer. As I said before, I re-treated this tooth with the GentleWave root canal technology, and I don’t think that I would have been able to pick up that anatomy—that I was dealing with a tooth with a lateral canal—any other way. No joke. It’s crazy that something so small can have such a dramatic impact on the comfort of the patient, but the truth is that it really can. This canal is small but it’s mighty. 

Repeat after me: I solemnly promise I won’t underestimate lateral canals!

Even the tiny ones going into the furcation can make a tooth appear “cracked” and cause our patients misery. And our job is to make sure we get the patients who trust us out of pain.

Another Example

Let’s take a look at another case. This patient had no pain, but clearly had a problem.

Take a look and you can see the tooth has been previously treated, but there is some furcation breakdown. Once again, the root canal looks fabulous!

You can see from the bitewing that the tooth was not in occlusion, so the idea of a crack was just not in my differential diagnosis.

Again I had to think outside the box. What else could be wrong?

When I took the CBCT, all I could see was this ….

It’s a periapical lesion that went into the furcation. Ugh. This can be a very typical endodontic lesion, but I know that this would scare most dentists. This appearance of a PARL is normal to me, but I always want to know “why?” (and I absolutely hate it when it’s not obvious. It can become a real mystery to crack).

I let the patient know that I could try to retreat it, but that I couldn’t promise anything. Luckily, I once again had a motivated patient who wanted to try to save his tooth no matter what, so we moved forward with the retreatment.

I can’t help but emphasize how ordinary this appears. The root canal doesn’t look any different than the pre-op besides that little lateral canal, but it was probably the cause of the canal failure! Mystery solved.

My point here? We need to look at all the options with our diagnosis and consider that even the most minor lateral canals could be the cause of a failing tooth. Don’t be so quick to extract! Instead, re-treat to try and save a natural tooth. I promise, your patients will thank you for it.

A Tip-top Tool for Teeth with a Lateral Canal

Due to what I learned in the first case, I was quick to lean on GentleWave root canal technology to parse out these lateral canals. Not all dentists have embraced this tech, and I’ll be honest, it took me time to get used to it, but it has absolutely earned a place in my heart and I suggest it to anyone who wants to up their endo game.

The difference it has made is in the comfort of my patients and the little (but really-important) things I find as I obturate cannot be underestimated. You can read all about  my GentleWave recommendations here.

I know one thing for sure—it’s irrigating better than my syringe. I don’t think that I could have accessed the lateral canals I described here with conventional root canal methods. What would I have done without my GentleWave?

Remember: Not all “bad” teeth are cracked! Modern-day root canals have come a long way, thanks to new endo technology like the fabulous GentleWave, so why not take advantage?

Want to test your knowledge on tricky cases like this? Put your endo skills to the test with my Endodontic Know-How Quiz.

– Sonia