The Root Canal Retreat That Changed My Perspective on Endodontic Failures

When you’re in practice long enough, you’re guaranteed to see some of your work come back… and well, it won’t be working. No matter how much experience you have or how good you are, you will have failed root canals. It’s simply part of the job—and part of life!

The key is how you choose to look at them.

In today’s blog, I’d like to invite you into my world to examine one of my own endodontic failures: a root canal retreat from 2015. My hope is that by getting vulnerable with you all, I can use my experience as a teaching tool that can shift your outlook on endodontics and boost your self-confidence. Greater trust in yourself is what will supercharge your progress and transform your practice.

So ladies and gentlemen, grab your popcorn, ’cause I’m putting myself in the hot seat!

Welcome to the Real World

Before we get into the details of the root canal retreat case that changed my mindset on endodontic failures forever (seriously—it’s pure gold), I want to establish an important fact:

The only thing that can prepare you for the real world is the real world.

Going through four years of dental school (and for me, two years of endodontic residency) can lull us into a false sense of mastery. We learn SO much during that time that it can be easy to feel as if we’re ready to spread our little dentist wings and soar into our career. 

In my case, I was always a good student who studied hard and did well on tests. So, when it came time to graduate, I understandably equated effort with expertise. I learned all the things to the best of my ability, so that meant I was ready to succeed… right?

Not right. Not right at all.

My bloated endo ego had prevented me from recognizing dental school and the university setting for what they were: a safety net. Being able to ask someone for help at every turn made the experience easy. There was a lot of support and little accountability. But that level of accountability changed as soon as I took off that cap and gown. Suddenly, it was all me and only me. My safety net was gone.

The reality is that dental school was never meant to fully prepare us for the real world, and having that expectation sets us up for failure. There are lessons that can only be learned through experience, and that’s the motherfucking truth.

Yet as scary as that is, it’s an incredible opportunity for growth. When you’re forced to operate without that safety net, put your skills to the test, and make mistakes, it’s like the universe is continuing your education. The only difference is that, this time, there’s no one guiding you through the curriculum. it’s entirely up to you to open your eyes and ears and actually learn from those lessons.

The Root Canal Retreat That Changed It All

With that in mind, it’s time to explore the root canal retreat that has completely changed my perspective on my own endodontic failures. To do that, though, we’ll need to turn the clock back all the way to 2015…

Different Decade, Different Endo

I first saw my patient nearly a decade ago when his dentist referred him for a retreatment on tooth #19. The patient was asymptomatic at the time, but his dentist had seen a “dark shadow” on the radiograph. Here’s the pre-op:

Based on my evaluation, I diagnosed the tooth as Previously Treated and Asymptomatic Apical Periodontitis #19. 

Since it was 2015, I was doing endo a whole lot differently than I do now. For starters, I wasn’t consistently taking preoperative CBCTs, which is why you won’t see one for this case. I was also doing all of my retreatments in two visits and medicating teeth with calcium hydroxide.  

Any time that I’m doing a retreatment, I’m always considering the WHY behind the failure and what I can do to improve the clinical outcome. In this situation, I thought it was a case of the two cardinal rules of root canal therapy not having been followed. So, my treatment plan was to retreat the tooth and simply follow the rules. 

And that’s exactly what I did. I removed the gutta-percha and medicated the tooth with calcium hydroxide, business as usual circa 2015.

After a few weeks of allowing the tooth to soak in the medication, I brought the patient back to obturate the tooth and close it up:

At the time, I was happy with the result! I was able to achieve patency on all the canals and sent the patient on his merry way to recover.

Or… so I thought.

A Root Canal Retreat Déjà Vu

Years went by without me hearing anything from the patient. Then, in 2023, he landed right back in my chair for the same root canal retreat.

It’s never fun when you’re looking at your schedule for the day and you see a repeat patient—let alone for the SAME EXACT TOOTH! Those are the moments that just make you feel like a complete failure, despite having tried your best. Why do we always have to jump to the WORST emotion? Why do our limiting beliefs and our mental chatter always make us feel like shit? (Sorry, that was my mental chatter talking.)

Regardless of how I felt, I owed it to the patient to figure out what was going on. So, I took a new pre-op radiograph and this is what I saw:

How is it possible that a root canal that actually followed all the cardinal rules of endo had a lesion BIGGER than the original root canal?!? I think anyone reading this blog can agree with me that that root canal could not have been done better. Insane! Sometimes biology stumps me.  

But good root canal or not, the fact of the matter was that it had still failed. So, I needed to have a conversation with the patient to explain the situation thoroughly and make sure he understood his options. We could:

1. Extract the tooth, since the second root canal hadn’t improved things.
2. Do an apicoectomy on the tooth, since a situation like this is exactly why apicos were created (when orthograde treatment doesn’t work, we cut out the problem).
3. Do another retreatment, but do it differently. By 2023, my root canals had changed substantially. Not only had I started to take postoperative CBCTs, but I was also using GentleWave technology and laser activation to enhance the fluid dynamics of my irrigants, allowing me to achieve a deeper clean.

Any guesses as to what the patient chose?

When at First You Don’t Succeed, Try Again!

When it comes to patients, I swear I hit the jackpot most of the time, and this was no exception. Once again, I was blessed with someone who understood that times had changed and was willing to trust the process. So, I diagnosed him as Previously Treated and Symptomatic Apical Periodontitis (yup, he was now tender to percussion, go figure) and we did another root canal retreat—only differently this time.

While the 2D images don’t really do it justice, the 3D CBCT certainly does (which is why I sometimes take postoperative CBCTs now, too).

You can see in the coronal view that the canals are super connected:

It’s the axial orientation that really speaks to me, though:

Just take a moment to pause and see what I see! Do you notice the line between the two mesial canals? That’s where the bacteria was still lingering, and we needed to connect the dots! This isthmus is what apicos are used to clean out.  But, now we have a non-surgical way of getting the job done (probably in a single visit, now, too)! How miraculous is that? I really love this for my patients!

Fast forward to the present, and this patient recently came in for a 6-month recall. This is what he’s looking like now:

And when we compare the CBCTs side by side, you can REALLY appreciate the bone healing:

That lesion is shrinking, baby! Another tooth saved. Remember: Bone takes forever to heal, so this type of healing in just 6 months is incredible! And just imagine what that bone regeneration is going to look like after 6 more months. If that doesn’t make you believe in endo, then I don’t know what will.

My Own Endodontic Failure… or Something Else?

So, what does this root canal retreat case have to teach us about endodontic failures? Let’s unpack it.

After finally achieving the outcome I wanted for this patient, I found myself reflecting a lot on what had happened. My root canal had failed—there was no doubt about that. But did that mean that I myself had failed?

Or is it possible that I just didn’t have the resources at the time to get the desired outcome?

In an age of technology and lightning-fast innovation, improvements are being made all the time that help us achieve better results. For example, thanks to incredible advances in medicine, doctors can now successfully treat deadly outbreaks of viruses like HIV/AIDS. But does that mean doctors who came before them who didn’t have access to such treatments failed as providers? I certainly don’t think so—do you?

What I’ve come to realize is that even when you try your best, using every tool you have at your disposal, you’re not guaranteed a perfect outcome. There’s a lot that’s still beyond your influence, and blaming yourself for that which is outside of your control can only be detrimental to both you and your patients.

Think about it—had I let my disappointment in myself prevent me from providing retreatment as an option for my patient, we could have ended up performing an unnecessary extraction. I would have not only given up on myself, but given up on the tooth.

We can do better!

Shifting Our Mindset Around Endodontic Failures

Since this root canal retreat case, I have adopted an entirely different mindset when it comes to endodontic failures, and I encourage you to do the same: Sometimes, your root canals will fail, but that doesn’t make you a failure! All you have to do to be successful is not give up. Re-evaluate, approach the case differently, and above all, believe in your ability to save the tooth!

I need you to understand that your endodontic growth is NOT going to be linear. You’re not going to master endo overnight, even with the right training. It took me a solid five years of practicing before I felt I really had the hang of endo, and I experienced another couple of spikes in growth around year ten and year fifteen.

In the end, it’s all about the journey. Your growth—in endo and in life—will come from getting your hands dirty, encountering new situations, making mistakes, and learning from your experiences.

Want an Endo Mentor?

If you’ve always wanted to do more endo but never thought you had the gift for it (or lost your mojo after your own endodontic failure), I’m here to tell you that endo confidence is well within your reach! With the mentorship, support, and accountability of E-School with Coaching, my award-winning online endo CE program, you’ll be able to find (or regain) trust in yourself, enhance your skills, achieve better outcomes for your patients, and transform your practice.

– Sonia