There are some frustrating experiences that every dental professional faces during root canals. For instance, we often run into canal blockage in endodontics, as well as tough stuff like apical calcification and some serious curvature. 

These unexpected finds can really complicate your access and impact your chair time. Within teeth, some blockages and curves are drastic and obvious, while others are more subtle. Unfortunately, it’s the subtle ones you realllllly have to watch out for! They’ll make you feel like you’re doing something wrong—so it’s super important that you stay on the right path by knowing what to do when you run into one of these. That way, you can empower yourself to get unstuck and rock your root canal.

Canal blockage in endo: Dealing with the unexpected 

Recently, a dentist reached out to me asking about a specific case that was pretty dang tricky. 

She was doing a root canal on tooth #13. On the radiograph, the tooth looked pretty straightforward, but—you guessed it—she discovered that it wasn’t so simple after all! She sent me this image, a working length radiograph of tooth #13.

And before you look at it, the rubber dam IS there! The clamp is just on a different tooth, so you won’t see it in the image.

You better believe  my FIRST question to her was, “Where the hell is your rubber dam??” But don’t worry—she’s a pro and let me know she clamped a different tooth, so you simply can’t see it.

One of the canals was close to patency, but I wasn’t convinced it was patent yet. The other canal was short, and therein lay her frustration.

This kind of working length issue happens to me every dang day, and it’s important to know how to troubleshoot it because if you’re doing endo, it’s just something you’re going to come up against.

When you can’t get to length, I’ve got 8 tricks for apical calcification, navigating those nasty endo canal blockages, and mastering curvatures in root canals. 

I shared all of this with her, and I want to share it with you, too. 

1. Up first: Use smaller files. Not having any luck with your 10mm file? It’s time to think smaller so you can get down to that apex. I use 6 and 8 files all the time. In endo, if a canal is blocked then I’ll use a 21mm hand file over a 25mm one; the shorter files tend to work better for these situations.

2. And then: Toss the K files and get C ones. That’s “C” for “cutting,” which is exactly what you need for getting through that nasty apical calcification to 0.0. Rather than the “quarter turn pull,” this file needs to be used in a pecking motions. (More on my Top 10 Tools for Endo here.)

3. Next: If the tip of the file gets bent, then cut it off and keep using the file as-is. This will keep your tip more active and help it cut more efficiently. Don’t forget that you just shortened your file, though! This is also a great way to get more life out of your file instead of reaching for a new one. Easy peasy.

4. And when your hands get tired, use the M4 Handpiece! It’s freakin’ awesome! It basically turns your hand into a rotary file for busting through canal blockages when you’re doing endo and helping you get down to the apex. (You’ll want to make sure you keep that pecking motion when you use it.) I use one by Kerr, but you can of course reach out to your dental supplier for more options.

5. Also try curving your files beforehand. Straight files can get stuck, especially if you’re dealing with a curvature issue. Try precurving the file and seeing if that helps.

6. Start with a coronal opening. Want your hand file to glide to the apex with ease? Things will become a lot simpler if you remove the coronal interferences. While you may have to go back and forth between your rotary and your hand files for this process to work, don’t go too quickly and stress your files (or cause separation). It will take time and patience, but it could be the key to get you to that apex.

7. And then use some EDTA. Let it soak in the canals for a few minutes, then work your files in while it’s still there. It certainly won’t hurt, and it just might make all the difference.

8. Lastly: Put it aside for another day. Dealing with canal blockages in endo or navigating tricky curvature is time-consuming. And when you’ve been working on a tooth for a long time, you might need some time away. Especially if you’ve tried all these tactics and you’re still not having success. If that’s the case, place some calcium hydroxide and take a break. At the next appointment, you’ll have a fresh perspective (and a fresh set of eyes) to help you conquer that crazy canal constriction!

Hopefully, these tips and tricks for dealing with blocked canals during endo will help you problem solve the next time you run into something like this. 

Don’t give up! Remember, your goal is to save teeth! Working length and patency are so important to root canal success. 

Like I said—I’ve got you! Every. Step. Of. The. Way! 

You can do this! I’m with you every step of the way! For a little extra support when it comes to using your stellar endo tools, check out my Instrumentation Workflow.

– Sonia