The Role of CBCT in Modern Endodontics

You're listening to the Phil Kline Dental Podcast Thanks for joining us. I'm Dr. Phil Klein. Today we'll be discussing the impact of CBCT and 3D imaging acquisition, processing, and interpretation on surgical and non-surgical endodontics. Our guest is Dr. Ali Nasseh, a senior clinical faculty and lecturer at Harvard School of Dental Medicine for the past 27 years. He's on the editorial board for several dental journals and periodicals and lectures extensively on surgical and non-surgical endodontic topics. Dr. Nasseh is on the advisory board to NIH. NIDCR, and on the Instruments and Materials Committee for the ADA. He practices endodontics in his microsurgical endodontic practice in downtown Boston. Dr. Nasseh, it's a pleasure to have you on the show. Phil, it's always nice to be with you. So, you know, you're certainly an expert in endodontics. You've been involved with product development. You're in high demand for so many companies to get your opinion on new endodontic products and clinical protocol using those products that you've developed. products and sealers and it's very impressive your career what you've done and you're practicing along with teaching at harvard so we're certainly honored to have you on our show to begin i'd like to ask you um a very basic question just as a general start to this conversation and that is why is 3d imaging important particularly to endodontic therapy Well, Phil, if you think about it, of all of the fields or specialties in dentistry, endodontics is the one that seems to be the most blind. Almost in every other specialty, people are having direct vision, are able to assess problems and then make decisions based on that. In endodontics, you're dealing with an abstraction that you have to build an image of in your mind's eye. before you can treat it. Because, you know, much like an iceberg, most of the work that we're doing is on the, it's not at the tip of the iceberg, it's all below the gum level and in the bone and has to do with all of the pathways that roots and root canals take, the curvatures, the idiosyncrasies they have, all of the ramifications, the number of canals, none of which are obvious from looking at the tooth clinically in the oral cavity. And that's why imaging has been the cornerstone of all we do. in endodontics and you know we endodontics really became possible as a result originally of just radiography with regular x-ray imaging that gave us an insight without having the tooth extracted of what kind of anatomy and the number of canals and teeth that we were working with before we could access the tooth and treat it the length of the canals and so on But obviously, the original radiography was two-dimensional and it was compressed. So we were only getting information by looking at the shadow of the tooth in a two-dimensional way. And it really wasn't until regular radiographs moved on to panoramic and then CT imaging came around. And then more recently, CBCT, which is kind of a more confocal and rather cone beam. limited area with higher resolution became possible and software improvements to render these images with more resolution and being able to manipulate the image to get a little bit more contrast and a little bit more detailed information that we really got a chance to see what we're dealing with. before entering the tooth. And this was information that was really pivotal and, in my opinion, game-changing. I have done clinically, as you said, I'm a clinical endodontist and I love still clinical endodontics while doing innovation and so on. I've completed our 28,000 cases. The first 20,000 cases I did was without CBCT. And the last 8,000 cases I've done have been with CBCT. And it's almost on a regular basis when I'm sitting looking at the CT and my dental assistant is next to me and we're looking at the thing together. And I look at her and I say, look, I can't believe I did those first, how did I do those first 20,000? Because the information that we get from 3D imaging is just incredible. And it really helps make it my decision-making, not only about treatment plan and diagnosis and treatment planning, but also in terms of the treatment itself, more efficient and far more effective, in my opinion, actually, in my experience. Yeah. And I've talked to other endodontists that have said very similar things, Dr. Nase, is that they almost feel like they're cheating now. with this new technology. And in the past, they thought they had everything under control. They had good results, 97% success rate or higher. But now with CBCT, it's such a game changer. They say the same thing. How did I do this before with 2D imaging? So obviously, CBCT does more than just giving you canal length and giving you some idea of the anatomy. Can you walk us through very briefly? Give us an overview of the path that an endodontist would take or a GP that does a lot of endo that wants to incorporate CBCT into his or her office because obviously it's a cost. It takes a footprint up in the office. It requires a lot of training. What is entailed in this whole process of making this transition? Well, first is to kind of recognize the benefits it brings to your game and then try to make sure that your location has the capability of... as you said yourself, carry the footprint and the logistics of having people take the image. The image acquisition is actually a big part of the whole game. Just having the machine is not enough. You need to also have staff that are talented enough that they can learn from the instruction so they can capture a high-quality image because it starts with capturing the right image on a patient that is sitting still without movement, the right area, and then you can manipulate. the image with the software to a much better extent. If you don't have a good quality image to begin with, you will have very inadequate information and it's just not going to be helpful and that could be frustrating. So it starts by first recognizing the need and then making sure that you have the location to kind of do that. And nowadays there are a number of systems out there that are far... They're kind of modular, if you will. It all depends based on what kind of need you have, because CBCT imaging can be used for all kinds of additional imaging. If you're an orthodontist and you want to do cephalometrics and all kinds of additional imaging, or if you want to have full arch imaging for implants or additional craniofacial imaging, all the way down to... very local endo-quality images for cone beam imaging that are usually 80mm by 80mm or 40mm by 40mm, small little volumes that reduce the amount of radiation the patient gets and also reduce the field of view. As the smaller the field and so on, you can have... that have a far smaller footprint. So that is the consumer is going to have to take a look around and see what's available in terms of the space that they have. And they kind of run the gamut in terms of the price. It depends, again, based on the configuration that people want to get. And if all of those things work, then it... becomes a question of, are you willing to invest the time to learn? You're doing endodontics, Phil, all the time or fairly frequently. This is really necessary. To me, it's the equivalent of really using the scope or loops, if you will, even. It's just your eyes ahead of time. And it makes a big difference clinically. So where would a dentist or endodontist get the training necessary to utilize CBCT in the most effective way? to really influence their efficiency, their treatment, and their outcomes in endodontics? Usually, each manufacturer have their own set of KOLs and courses that they may recommend, people who can help explain that particular software that they offer. There are a number of independent... endodontists and dentists and surgeons out there also that have different kind of platforms for teaching this particular modality. So there are a number of venues available. It's probably best if you decide, the first question is to decide which system people want to get. And then based on that, maybe speak to that specific company to see who are their KOLs and what kind of educational platforms they have. Because there are different software. And while all of the CBCT technology follows the same... concepts of image manipulation and understanding the image for optimization, the software, the GUI and the platform, the image interface is different and it's best to kind of learn from the experts in that particular area. I personally use the Merida software and the Merida machine in my office. I have the X800 and I've been very happy with it. So everybody, you need to kind of ask your colleagues and people around you who have them, your endodontists and so on. and see what they're working with. You mentioned you used the X800 from Jay Morita. Anything special about that machine that you liked or how did you get started with Jay Morita? So for me personally, I started the Jay Morita. That was the, you know, the word on the street was they had the best quality in terms of... the imaging, image processing, because there's really three specific aspects of imaging when it comes to radiography, which is the image acquisition that we talked about, how important that is. That's up to you. And of course, also the hardware that the manufacturer provides for you. The second one is image processing. And that's essentially the secret ingredient that each manufacturer has in the way they... the image that is captured from this digital sensor and interpret that into an actual image. And then each software has its own additional type of tools that helps you extract more from the raw data in terms of specifically manipulating the contrast and adding sharpness and getting that. proper gamma that will help you the much better image visualization and then lastly it's image interpretation and that image interpretation is partially your own brain that's based on your experience and your knowledge of your fundamental understanding of pathology and diagnosis and then you know interpretation of imaging into that And so the image processing is a key thing, and Morita had a good reputation on that front, and that's how I ended up going with that system. So after doing, Dr. Nassi, you mentioned 8,000 cases using CBCT, in addition to the 20,000 you've done using the legacy 2D imaging. So with CBCT, what would you say the greatest benefit has been to you regarding your endodontic treatment? 3D technology ahead of time will help you tremendously with diagnosis. And we know that diagnosis is the most important component of treatment planning. And I've always said that treatment planning is the number one cause of our success, right? We succeed at the, I always say that the fate of your treatment is sealed at the moment of your decision-making. And that's treatment planning. Like, you know, am I going to handle this case? How am I going to handle all of that treatment planning that goes into it? is essentially based on your diagnosis and having the proper diagnosis. And if 3D imaging ahead of time will help improve your diagnosis, by proxy, it will help improve your success rate. Now, of course, as soon as you say something like that, academics are like, well, show me the research that shows. This is not one of those things where you're going to show away research. It's kind of one of those things that we're like, look, we know there's a ton of research that shows that CBCTs help improve your diagnosis. We also even have... research that shows CBCT helps change your treatment planning. People, you know, there have been studies that have been done where a group of endodontists were given all of the available information to make a decision about a treatment plan. And they were supposed to make a treatment plan for a given two. And then they were given, the same people were given a CBCT image, a 3D image. And then they were asked to look and evaluate that. And they wanted to see if there was a change in a treatment plan based on the 3D imaging. And they found that almost in 50% of these cases, the endodontists changed their treatment plan as a result of the additional information. So additional information that is provided by the CVCT imaging, which helps build a far more accurate three-dimensional image of the tooth pathology and the anatomy that you're dealing with, will help you decide far better what is the best treatment plan for a given tooth. In a non -surgical case, what are the traps? What are the booby traps in there? Where is the canals coming together? What's the extra canals? Is there a sharp radius curvature at one area? Those things will help you not only find all the canals, not only get in there and go immediately where you should go, but also know in which areas you should be careful about sharp bends so you're not going to break files. When I practiced endo in Philadelphia, I did a lot of retreatments. That was a big part of my day. How does CBCT help an endodontist now when it comes to retreating a tooth? If it's a retreatment, it's going to help you decide whether you should do retreatment versus apicoectomy because it's going to help you understand if there's a missed canal, you don't want to do an apicoectomy because it doesn't work as well if you don't treat the whole canal. If you have a missed canal, that should be treated non-surgically. It should be retreated. But if you have a tooth that has been non-surgically retreated, but you have a very big web or anatomy that has a long isthmus on a canal, then retreating those doesn't really do as well. So those are the cases that you want to treat surgically because it will help address the problem. If you have a broken instrument at the end of the canal that's not going to be able to remove or you have a big ledge, those are surgically better treated than non-surgically. it will just help you understand what is, again, it goes back to diagnosis, what is the etiology of the pathology? And based on that, now you can better be able, based on the first principles of what is the mechanism by which endodontics works, decide whether this should be treated surgically, non -surgically, or it should just be extracted because there's a hidden massive strip perforation on the side of the tooth, or sometimes you can see a crack on the tooth, but that's not quite as... predictable. So there's no doubt, Dr. Nasseh, the benefit of CBCT and endodontics. What do you say to the dentist who feels, well, I've been doing this for a long time. I'm interested in CBCT. It would be nice to have, but I'm already getting a success rate of 97, 98% with my endodontic cases. What's your response to that dentist? The principles of endodontics do not change because of CBCT, but it will help you know where the hidden anatomy is, and it will help you save a lot of time. So to my opinion, it will improve your success rate to the extent where it will help you treatment plan better in terms of, well, should it be treated or this should be extracted? Should it be retreated or should it be surgically treated? There's no question about that because you have more information and you're wiser for knowing what the cause, the ideology of the disease was in terms of deciding. But in terms of just the day-to-day operation on a regular case, what it does is it will help you be far more efficient because just like implant therapy, right? I mean, if you were supposed to reflect the flap and then sound the bone in order to find out where the bone is and so on, before you can make a decision as to which direction you should put the implant, that'll take a lot of time. But if you know exactly at a time where the bone is, the danger areas are, you know, which direction should the implant go ahead of time, that will save you a tremendous amount of time. So I feel that endo is now at a juncture, just like implants was, implant therapy was a while ago, where we're going to spend quite a bit of time ahead of time, just looking, absorbing the information out of the CT image, building, rebuilding, and improving that mind's image of the space that we're going to be working in before we go inside the tooth so that it's all planning and then execution, as opposed to before where it was execution, evaluation, exploration, rebuilding that image, and then execution. So we get rid of all that stuff and we go straight to the point. It seems to me as an endodontist that CBCT will certainly, with all this information you just described that we get out of it, will remove most of the surprises. Because often when you start a case, it looks pretty basic and pretty routine. And then you get surprised once you get in there. And that changes the whole sentiment of doing that case. And it could be a little bit stressful, especially while the rubber dam is on and you've got two patients in the waiting room. Having that information ahead of time and planning ahead, like you described, seems like it would eliminate a lot of these unpleasant surprises that endodontists and general dentists who do endo face when doing these cases. Can I add one quick thing here? Is that one area where these are really, as what you just said, what you find out that is very difficult when you get inside, this information, for example, a lot of times with lower anterior teeth, as we know, you take a regular image, front-facing periapical. and it looks like a root canal that's done beautifully, but then there is a large lesion at the apex of the tooth. And all this question was, well, why didn't the root canal work? Now with CBCT imaging, when you look at that axial section, when you cut the root in a cross-section, you look and see that what Vertucci and all of the other people, the anatomy people had shown us, is that a good 10% to 20% of these can have multiple canals. And when they do have the multiple canals is that when you end up having a separate exit, you'll end up only treating one buccal aspect of the tooth. It looks like a beautiful root canal but you have a whole other lingual root canal that hasn't been treated or has a big isthmus and the bacteria from that is causing the failure. That explains a lot of these things now. ahead of time so you can go ahead and treat that non-surgically retreated as opposed to go in there and do apico where we used to do before and then the apico would fail and we would say oh apicos don't work but it helps improve the success rate of apicos even because you apply it only in those cases where it should absolutely be applied yeah yeah that is so logical what you just said let me ask you about root resorption root resorption has been very difficult thing for some dentist to manage especially not knowing what the etiology is and we know that root resorption comes in different forms we have cervical we have lateral we have internal we know that in an internal root resorption we need vital cells to perpetuate that whole process so there's a whole science behind root resorption does cbct help you diagnose root resorption and therefore help you treat the root resorption in the proper way Oh, for sure. I mean, in area of root resorption, it is probably the most important and necessary tool that you're going to have because it's through that. I mean, I've used this term on root resorption that I call surgical accessibility. That's a critical point of finding out whether you should treat these cervical resorptions or not, whether they were surgically accessible, whether you're going to by touching them, you're going to expedite tooth loss. So this information previously, I remember back in the day when I was getting into training, the argument over external and internal resorption was big. And always you had to get multiple angles to see if the lesion would move, therefore meaning that it's internal or external. Now, all of those arguments are moot. You just take a CT. You have all the information you need to know. And you find out if it's internal resorption, in which case that's going to be easy to treat as the better prognosis. Sometimes you can even see if that internal resorption has now caused perforation, in which case it's going to affect the prognosis. That becomes better for communicating with the patient. And then you also now see ahead of time whether you're going to end up having an external resorption case, in which case that's going to have a little bit of a different prognosis based on the classification. It was class 1, class 2, class 3, class 4. find out through your CBCT analysis, you determine if the area, if the location, is it on the buccal or on the lingual, is it surgically accessible, then that'll help you decide whether this is one of those teeth where you're going to have to actually treat either non-surgically and observe or non-surgically and surgically combined based on the classification, or is it a tooth that you should just kind of... and let it ride into the sunset until it becomes a problem that has to be extracted. Because some of these cases, if you actually jump in there and start to do treatment, you can expedite and cause an infection of that resorptive defect, and that's going to expedite tooth loss, whereas the resorptive defect could otherwise stay in place and slowly grow over time. And that's another thing, too, is that CBCD will give you a much better information, because there's two main factors you need, Bill, as you know, for resorptive repair decision-making. One of them is what I call surgical accessibility, and the second one is the rate of growth. We all look at these images still at a moment in time, but we don't know what the rate of growth is. Oftentimes, people make a decision to move on and do something invasively without knowing how fast this thing is growing. Having the two CTs and comparing them together would be very helpful before you decide to do something aggressive. Recording those images over time using CBCT, absolutely, over a period of time. I want to ask you about the future of imaging. in endodontics? What do we see in the future? But before I get to that, based on what we're talking about here, it sounds like to me that it's almost a necessity based on a patient coming to an endodontist, laying down in the chair, trusting that doctor to give them the standard of care that's available today. It seems to me that if you don't have a CBCT system set up as an endodontist, a specialist, you're not really providing standard of care. I mean, is that too? extreme to say something like that? What's your opinion? No, it's not extreme. Of course, you know, standard of care is a legal term. So it's CBCTs are still not considered standard of care. In my opinion, they are kind of excellence of care. They're far better quality, but without a doubt. If you're doing only endo, CBCT should be a part of your practice, just like scopes are, microsurgery is, use of ultrasonics are, nitile rotary instruments are. These are things that have really been shown to help improve the quality of the work that we do. So CBCT technology, without a doubt, and I think at the beginning... I myself, before the last 8,000 cases, I was one of these people who said, oh, we don't want to have radiation. What about radiation and all that stuff? As I did more research into the topic, I found out that there are a lot of issues in the way the term radiation has been used. And in fact, the American Association of Physicists in Medicine put out a position paper. talking about the fact that the Alara principle and a lot of these things that we've been kind of talking about and touting for the past many, many decades are really obsolete and they're really not helping. They're just merely scaring them from making decisions that actually help improve the quality of the care that their surgeons provide by creating this scared kind of atmosphere or scary atmosphere. And that there's really no scientific research that shows that the levels of radiation that are produced by any of these kind of imaging is of any kind of worry for the patient. Well, it's certainly less than CT. Medical CT is much more radiation. Because we're getting a much narrower scope of radiation through cone beam, right? Much, much narrower, actually. And it's less than a chest x-ray getting a CBCT radiation. So as far as the future. of endodontics? What are we looking at? And if you can wrap that up in a minute and a half. Yeah. So to quickly just tell you, I think the future is going to be really exciting as we're moving, as we are now living in a digital age, the understanding of the role of imaging through image processing. And now with the latest addition of AI to this imaging. is going to really catapult our information as surgeons in this field before we get into the patient to a whole next level. So the AI, I predict, is going to come in and be able to interpret the image, find a pathology ahead of time, and give us guidance and suggestions in terms of having a far better access to those. to the raw data that we're getting out of the CVCTs with its most optimized kind of form of manipulation into where the pitfalls and difficulties are in the canal, how many canals there are, how it should be addressed, you know, what are the potential areas that you should be careful about. And in fact, I think at some point down the line, there would be all kinds of different forms of recommendation. for the way we're going to go about what kind of technique you should use for this particular case, what you should use. So armamentarium, all kinds of stuff is going to come. It's going to be very helpful. It's an interesting future ahead of us with AI. I'm actually developing an AI app myself, so that's going to be interesting when that comes out on diagnosis. What an exciting time to be involved in endodontics. And how long have you practiced clinically? And now close to 30 years. Okay. So you're still a young guy. You're still a young guy. You got a lot left. That's right. A lot of gas in the tank there, Dr. Nasseh. Well, listen, you've been a total innovator in our profession, especially in endodontics. We all have tremendous respect for you. And we're so happy that you were on the show. You have so much to offer us to learn from. And we look forward to having you on more programs very shortly. Thank you very much, Dr. Nasseh. Absolutely. I look forward to being back. Thank you again, Phil, for everything. Bye-bye. If you've been enjoying our podcast, we'd love to hear your thoughts and feedback by leaving a review on your favorite podcast platform, whether it's Spotify, Apple, Google or any other platform you listen on. Leaving a review is a fantastic way to support us and help others discover our show. Thanks for listening. See you next time.