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
These are great suggestions! Thanks for sharing your knowledge.
Thanks for all your support Meena!
-Sonia
Very usefula me helpful practical tips ma’am..
Thank you so much 💕
I’m glad it’s useful for you!
-Sonia
thanks for the knowledge, I had such case in the clinic.
Thanks for reading!
Thanq. Ma’m very helpful ma’m i hve one question. Ma’m can B.D.S practice in Abroad if yes then how?
I am sorry, I am not aware of the admissions process and that is not the intention of this blog. Best of luck to you.
-Sonia
UR SMALL SMALL TIPS REALLY R A BOOST FOR ME TO PERFORM ROOTCANALS WHICH R TOUGH. THANK U SO MUCH MA’AM N KEEP SHARING.
I’m grateful this was helpful for you!
-Sonia
Excellent and efficient tips! Thank you
Thank you! So glad you got something from this!
-Sonia
Really helpful..
yep, always good to call it a day when things aren’t going your way. fresh eyes always so helpful to both you and the patient. <3
Agreed! And thanks for reading!
-Sonia
What do you use to cut a slightly bent tip of an instrument off with? Thanks for the blog and information.
Terri – Any dental scissors you have should work.Thank you for following!
-Sonia
So useful tips mam. Thanks a ton for guiding with these useful tips . Hope to see much more tips in future.
I’ll definitely keep the tips coming!
-Sonia
These are such a simple but practical tips. Thank you so much Sonia for inspiration!!!
Thank you for reading – so happy to help!
-Sonia
Great tips. A question about using C files. Does your “pecking” motion include watchwinding the file at all, or is it purely in and out motion? Also, my understanding is C files are end cutting. Do we need to be concerned with ledging/perforating with these? How do we know we are still following a calcificed canal vs. ledging?
I just found your website and love the tips you are sharing. Thanks again!
Typically when it’s calcified I use a pecking motion because the calcification won’t allow me to watchwind. But I guess you could say there’s a slight bit of a watchwind when I use ANY file. But keeping the file straight in a blocked situation really helps. And there’s always a risk of transportation and ledging with any file, but with smaller C files there is less risk.
There is a very typical feeling I call a “stick” with my hand file that lets me know I’m still in the canal. Small files, plus EDTA, will help you stay in the canal.
Hope this helps!
– Sonia
That helps, thanks again!
Thanku for the tips Mam!! I’m sure these will be of great help.
You’re so welcome. Thanks for reading!
-Sonia
Hello, recently I’ve received some advice to leave EDTA gel inside calcified canal.. have you ever tried that? And will it do any harm leaving it inside the canal for 5 days?
Hi!! I don’t like to leave EDTA in the canals for two long because it will corrode your dentinal tubules. EDTA is something that I always wash out. Hope this helps.
-Sonia
I have tried everything during a RetreAtment of 46 3 canal
With 3 mesial roots and distal
When viewing the x ray one of the mesial roots was filled about 4 mm short from the radiographic apex
And the distal root was filled completely
But the failure was due to the missed second mesial canal which was found by me and instrumented
Is it okay to fill the first mesial only 16 mm insted of 20 mm due to the impossibility of reaching the radiographic apex due to calfication i wasn’t able to overcome ?
The missed canal had a apical leaion
Hi there!! There are studies that show that if you are short in a necrotic case or there are percussion symptoms, for every mm that you are short, your success rate drops by 14% per millimeter. So, never finish short and always be patent. So, if you are 4mm short, then your success rate just dropped by 56%. I have a rule, if there is a lesion, then there is a canal. Endo is tricky and you have to learn how to work those calcifications without giving up. If you can’t get to the end, then refer it to a specialist. It may be that at this time, the patient may need an apico too. Hope this helps.
-Sonia
I love all the tips!
Thanks Rebekkah!
-Sonia
thanks ma’am for sharing ur simple tips.. i look forward to ur advices n tips evry time u put up.
Thank you – I’m so glad you’re following!
-Sonia
Thanks ma’am it’s really helpful for me, really had trouble with blocked canals,thanks a lot
Yes, they can be tricky! Glad to be of help! – Sonia
Absolutely great tips!!! Thank you!!!
You’re so welcome! – Sonia
Thanks for this case and your great tips. I will definitely try the C-files because I do use #6 and #8 files regularly ,however they are so thin I have a hard time feeling pressure with them and they bend easily.
Glad you liked the tips! Let me know how it goes when you put them into action! – Sonia
Thank you mam..thanks for these tips…it will sure help me in calcified canals…thank you very much
You’re very welcome – glad to be of service! – Sonia
Mam…please some input on cracked teeth…how to identify theses..
Vikas,
That is a great question and is something that I dive deep into in Eschool since it is such a special topic and requires more attention.
-Sonia
Thanks Sonia for your suggestions and useful tips. Really appreciate it.
You’re welcome – it really is my pleasure. – Sonia
Thank u mam
You’re very welcome. – Sonia
Hello ma’am,
Your trics are benificial..
Thanx:)
That’s great to hear!
-Sonia
Your tricks and tips are really helpful. I love reading your blogs. Thank you very much Dr. Chopra for sharing your knowledge and experience.
Thank you so much for the feedback! I’m glad it’s useful for you.
-Sonia
Thank you ma’am very useful for we beginner dentist
I’m grateful to hear it, Dr. Rukhsar!
-Sonia
Most of these blockages are iatrogenic. Canals calcify top down, most of these are small pulp stones that get jammed down during negotiation. Good coronal flaring before you try and reach apex and good irrigation tend to reduce these problems
Thank you for your comment.
-Sonia