Course Karma’s Top Endodontic Instructor of 2021
January 25, 2022
Root Canal Treatment of a Mandibular Molar (The Other MB2: The Second Distal Canal)
January 26, 2022
In my line of work, I’m often asked about periapical lesion classifications. How do I know if it is scar tissue or an active lesion, especially when the lesion is small and/or, more importantly, asymptomatic?
To which I say, “IT’S COMPLICATED.” My answer is usually multidimensional, and I can’t know for sure until I have an understanding of the whole tooth story. Many professionals leave these types of cases alone, while others treat them no matter what. There’s definitely a debate around this topic, but I’d like to throw in my two cents, so you know where I stand on the subject.
Let me walk you through two cases dealing with periapical lesion classifications. Both patients were asymptomatic, but the treatment plans were different.
The First Tooth Story
Case #1 had a previous root canal on tooth #8. You know me, I went straight into diagnosis! There were normal probings, no pain to palpation or percussion…the tooth was so asymptomatic that the patient was questioning why he was even in my office.
You know what kind of patient I am talking about, right?
Well, there was definitely a reason he was there! My diagnosis for this tooth was Previously Treated and Asymptomatic Apical Periodontitis #8.
The CBCT shows the periapical lesion a bit more clearly.
And you can see from the coronal view and the axial view that there’s a bit more surface area to the canal than what was obturated.
When I see something like this, it makes me question the disinfection protocol from the original root canal. Are there still original bugs in that canal that could potentially flare up on the patient in the future? Especially on a Friday afternoon or the weekend when nobody is available? In this case, I think that’s a possibility, and that is bad news for the poor patient.
HECK NO, I’m not leaving this one alone! I would treat it.
And if you’re worried about the patient refusing treatment, don’t. They’ll unfortunately be in pain before long, and they’ll be back, swearing you’re some kind of tooth prophet.
Patient education is the best medicine here, and I would show them the imaging so it’s crystal clear why the patient is in my chair and why I’m giving them the treatment plan that I am.
It’s all about setting their expectations properly! They need to understand what can happen if they don’t treat the tooth.
These types of cases take me more time during the consultation because I know the patient needs to have a deep understanding of what is going on in their body in order to make an educated decision. And that education has to come from me (or you 😊).
The Second Tooth Story: The Diagnosis
This patient had a strange sensation in the upper left area and was nervous that “it was this tooth again.” He couldn’t say 100% that this sensation was coming from tooth #14, but proceeded to tell me about how he has had two root canals previously performed on this tooth. Not gonna lie, that’s pretty rough. The first time, “they missed the fourth canal” he said. He remembers there being a really big dark area around that tooth on the x-ray, and it was painful, and he was also swollen at the time.
He had a lot going on, and had previous oral surgery in the area too. Here is the PAN.
So, I did my diagnostic tests like usual, and they were pretty inconclusive. I couldn’t reproduce any symptoms for this guy. His probings were normal and there was no pain to palpation or percussion. All the other teeth in the quadrant tested normal.
So, next we went to imaging and I took a CBCT. The sagittal view did show a small lesion on the MB root. My diagnosis for tooth #14 was Previously Treated and Asymptomatic Apical Periodontitis.
I then looked at each root individually in the CBCT. Here is the palatal root.
Here is the disto-buccal root.
And the MB root.
The Second Tooth Story: The Decision
The palatal root and the disto-buccal root look pristine, so we’re good there. The bone is healthy and the PDL is intact. It’s the MB root that has a little something funky going on, but as I listened to my patient and learned he had a big infection, one that even he could remember was big, and there was a missed canal (usually the MB2 right?), I concluded this area was most likely one that was healing. This periapical lesion probably started very large and is now much smaller.
I also like the quality of this root canal, and feel like it was done well. So for this one, I would like to leave it alone until I see the symptoms worsen. This area could very well be scar tissue from something that was really big at one time.
Truthfully, I don’t really believe in scar tissue, but if there is such a thing, it would be represented in this case. Remember, only some histology would give us the real answer.
On a side note, I thought perhaps something could be going on with the hardware from his previous surgery, so if the problem persists or gets worse, then perhaps a follow-up with the surgeon wouldn’t be a bad idea. I also made him aware that, if the tooth is the problem, it would most likely start to get really sore when chewing or biting and, if that happens, he should return to me for further evaluation. Again, it’s all about setting expectations!
The Takeaway about Periapical Lesion Classifications
You can’t just make a guess as to what’s going on with your patient and assume everything will be okay. That might work sometimes, but it definitely wouldn’t have worked in Case #1!
So in a nutshell, use your critical thinking hat and really evaluate the endo along with your patient’s symptoms. Periapical lesion classifications can’t just be guesswork.
- Listen to your patient and ask questions until you know the entire tooth story.
- Is there any sign of missed root canal anatomy or more surface area to the canal that could be the etiology for root canal failure?
- Is it a quality obturation?
- Is there any coronal leakage that might create a lesion or a new infection?
- Is there any immediate, necessary restorative care that would prompt you to treat now versus later?
- Are you going to watch it? What is a reasonable length of time to watch it? And do you know WHY you’re watching it and what changes you’re looking for?
- If your patient totally refuses treatment, make sure you document the discussion.
I think there will be many different opinions on this topic and how to approach it, so it will be interesting to hear what you have to say in the comments. I hope you can see the difference in these two cases and how my rationale works in both.
You never know from a glance or quick assumptions. Sometimes you catch someone on a good day when they aren’t having much pain. You don’t want to brush it off and put them in a situation where the pain can sneak up on them later, when you aren’t available to help.
Use your best discretion. And, as always, empower yourself to save those teeth!
– Sonia
16 Comments
Thank you mam, you have really helped me improve my endodontic practice
Comment *I totally agree with you
In my 33years of endo practice as specialist I always act as you described the 2 cases and I always guess
In first case .if it is recently treated#8 .the periapical lesion is going to be heal.If it’s a periapical infection it should be painful.
Really nice post! Always a struggle to decide treat or do not treat.
Dr. Nimbalkar,
I am so happy you are finding my content helpful. Thank you for reading!
-Sonia
Dr. Alberto,
Thank you for your feedback😊!
-Sonia
Dr. Tehreem,
Not all periapical infections are associated with pain. So be careful with your assessment here.
-Sonia
Peter,
Thanks for reading! It’s all about critical thinking here.
-Sonia
So this decision is important when placing an implant adjacent to a tooth with previous RCT. Hypothetically, say you have a small lesion, but the RCT looks good. If you cannot determine a reason why the lesion is there (like your second case), would you assume there are bacteria there and recommend retreat?
Kimberley,
I usually assume lesions that have been there for some time have some bacterial process going on. I am always looking at the quality of the RCT and seeing if it can be improved. In a case where the tooth is next to an implant, I may more inclined to retreat to see if I can get it heal instead of having a watch and wait attitude. The success of that implant is very important and I think worth the investment of a retreatment.
-Sonia
Hello, I have like a pressure discomfort in my tooth #9 area..actually where the tooth was..had a root canal then an apioctomy still had discomfort then had the tooth removed and an implant put in and I still have the pressure there after 3 years..saw multiple doctors..wondering if you offer any help into what I’m feeling..it’s very uncomfortable and usually flairs up afternoon into the evening…just wondering can it be anything with the the scar from the apioctomy? Any help is appreciated at this point…
Hi Anna, Dr. Chopra’s support team here. Thank you for reaching out about your case and I’m sorry to hear about your situation. In order for Dr. Chopra to give you an opinion on your case she would need to see you as a patient.
If you are near the Charlotte area you can book a consult directly with her office here: https://www.ballantyneendo.com/ Dr. Chopra also offers virtual endodontic consults, which you can book using this link:
https://bookus.page/soniachopradds/soniachopra/virtual-consult. Please scroll down to read the Disclaimers and Terms & Conditions prior to booking your virtual consult. After you pay, we will reach out to schedule your call!
Hi Sonia! Thanks for the article! It looks like I have a periapical lesion on my lower front just left the center and I’m wondering about a study I found that says they were able to heal 90 plus percent of 50 patients that had periapical lesions non-surgically. They only used saline to clean out the canals and Buckley’s formocresol to clean the debris. About halfway through the article, it says the following, & I wanted to get your opinion about what they say here:
“In this study, only normal saline as irrigant and formocresol as antiseptic agent, were used, for obtaining an unbiased post-operative result as compared to other intracanal medicaments such as sodium hypochlorite (NaOCl) and chlorhexidine. Extrusion of NaOCl into periapical tissues can cause severe injury to the patient.47, 48Similarly,chlorhexidine cannot dissolve organic substances and necrotic tissues present in the root canal system and is unable to kill all bacteria and cannot remove the smear layer.49, 50Normal saline is an isotonic solution to the body fluids and is being universally used as an effective irrigating material in all the surgical procedures39 and has no side effects when used periapically.51-53Formocresol is one the oldest medicament used as antibacterial agent in the root canals and is still considered a gold standard by which all new modalities are compared.54 It was introduced to treat non-vital permanent teeth in the United States by Buckley in 1904.55 Studies have shown formocresol therapy to have a success rate between 70% and 90%.56 It is therefore both a potent bactericidal and devitalizing agent. It kills off and converts bacteria and pulp tissue into inert compounds.57Exogenous formaldehyde has a biologic half-life of 1-1.5 minutes and is quickly cleared from human plasma.58 When used judiciously, formocresol is a safe medicament.”
-Do you use hypochlorite (NaOCl) and chlorhexidine?
-If not, may I ask what you do use?
-Are these procedures in this study classified as root canal procedures?
-do you ever use this procedure on periapical lesions and if you do, what’s your success rate?
Thanks in advance for any help you might be able to lend and helping me understand all this stuff.
Here is the study: https://truevaluedentalinstitute.in/2021/08/12/periapical-lesions-nonsurgical-conservative-approach/
Hello there! For questions like these, the answer is generally complex and long-winded — even more so than I would be able to put in an email or a blog post.
However, this is exactly why I created my E-School endodontic CE program for dentists, which dives into complex topics like this. I invite you to consider joining E-School: https://drsoniachopra.com/e-school/ and if you choose the Coaching option, I will be very happy to help you personally through coaching calls and a private Facebook group.
Alternatively, you can book a virtual consult with me here: https://soniachopradds.thrivecart.com/clinical-dental-consult/
Is it possible for a previously treated root canal (i.e. molar with a missed canal) to be asymptomatic even several years later? Even if the nerves of the treated tooth would not transmit pain causing reinfection to be asymptomatic, would there eventually be pain in the area as the chronic infection worsens?
Hey, Cub!
You can definitely have an infection with no pain. I have had patients with no pain for decades and really big infections. That’s the whole idea about chronic infections. The body just finds a way to deal with them.