The Challenges of Restoring Endodontically Treated Teeth

You're listening to The Dr. Phil Klein Dental Podcast Welcome to the show. I'm Dr. Phil Klein. In today's podcast, we'll be discussing not only the techniques associated with the post and core procedure, but equally important, why each step is essential to long-term clinical success. Our guest is Dr. Lou Graham, who graduated from Emory Dental School and is an internationally recognized lecturer, extensively involved in continuing education for dental professionals. Dr. Graham, pleasure to have you on Dental Talk. Great to be back, Phil. Yeah, it was good to see you in, I think it was Chicago. We saw each other at the convention. There was a lot of meetings there. You were very busy talking to a lot of people, but I'm glad we got to say hello. And it's good to see you still. You're still on the educational tour, which is awesome. Totally. So there are many dentists and even endodontists who don't advocate the use of posts for endodontically treated teeth. What's your feeling on that? Are they wrong? I do. I think the literature proves them wrong. And I think the literature and most of the literature, it's interesting, is the literature you always read, which was Journal of Endodontics. And that's where I get all my research from. A lot of it, I'm post and course. On my normal webinar with you next week, I go into a study that compared post and course in Journal of Endo, it's about seven years ago, versus course alone. And it was quite interesting that it was a significantly higher failure rate with just composites alone. And even, which shocked me, higher vertical fractures with composites alone than comparing it to fiber posts, fiberglass posts. Yeah. See, that makes sense to me as an endodontist because what the post is supposed to do is to distribute the forces from the crown area where the forces of mastication. originate and distribute it down the axis of the tooth which is what the root's supposed to do which is absorb it and then it's supposed to push it off to the PDL as an additional absorbing factor and that distributes the forces. So when you have this you know short tooth stub obviously you're taking all the brunt of the pressure on the tooth stub itself and then it's if you don't have a post to carry it down that could be a problem. But of course I think what you're saying is when we talked about this offline is that some operators over instrument the post canal and then use maybe a post that may be too wide that could cause a root fracture because you're weakening the tooth structure let me ask you this when do you make the decision to say this is a case where i need to use a post routinely i look at it as remaining tooth structure how much of the tooth remains if i have a large amount of tooth structure that remains let's take a maxillary first molar You sent me back a beautiful endo finding MB2 and everything, and I've got a great chamber, upper or lower molars. I routinely don't put a post and core in. I don't feel it's necessary to retain it whatsoever. I think when we don't have enough remaining tooth structure, I'm a true advocate of a post. And if a patient, a lot of our geriatric patients have limited remaining teeth, let's say, and I'm rebuilding, let's say, a canine. And the patients in canine disclusion or canine guidance, I a lot of times want to rebuild it with a post just to have a little bit more security that that crown's just not going to fracture off with a core buildup. Right. And so that's a call you make chair side, right? After you get the case back. Does the endodontist communicate with you and say, hey, Lou, recommend a post and core? Or is that something you just do on the field? You know, Phil, that's a great. conversation piece as a general dentist talking to you the specialist and endo and my feeling is i think the general dentist should be conveying the treatment plan to the endodontist in other words if this is an abutment for a bridge and you're redoing the endo what's the likelihood of success and who's going to determine that you are phil the endodontist and i think a lot of times we do have to be discussing are you going through a zirconia crown doing the endo and what's the treatment plan do you want to keep the access very limited and am i restoring the original crown you know just with a composite or am i redoing it and access for you could be critical so i really do believe communication between the general dentist and the endodontist and vice versa is critical Yeah, no, I agree. So that was going to be part of my next question is, is it necessary for the endodontist to know the treatment plan prior to completing the root canal? So you partially answered that. On the flip side, Lou, we do have issues as an endodontist where we need to open up the access prep more than sometimes we would like to in order to get the curve of a root that's just too difficult to access through. a very conservative access prep, and we don't want to jeopardize leaving necrotic tissue in the root canal system. What's your feeling on that? I believe that that's why we got to communicate, because if the endodontist goes, I don't want, the last thing you want is a broken file or an undertreated canal, no doubt about it. So if the dentist is saying to the endodontist, you know, it's a brand new crown, I'd like to keep the crown. and then the endodontist accesses it and has to let the doctor know, let's say in this example, that I need to make a larger access opening just in order to get to that challenging canal, then at least the dentist is prepared to discuss that with the patient when the patient comes back. Because no matter what, Phil, the endodontist can't do an A job, it's a guarded outcome. So I think the endodontist is critical to that discussion. When would that discussion take place, though, if the endodontist is seeing that patient in their chair? You're busy with a patient. They're not going to call you in the middle of their patient. They're going to do their thing, right? So I think what they have to do is explain it to the patient. Once they know, you know, understanding what your goals are, while they're in the chair at their office, they could say, hey, Dr. Graham was looking to save this crown. But under the circumstances, I'm going to have to communicate with him that. in order to treat this root canal properly, this is what we have to do. Is that how you see it? I do. And I just think then it's your responsibility to let Dr. Graham know before the patient shows up what's going on. It's important you email him and say, this was why I had to make my access a little bigger. Doesn't mean the crown can't be saved. It's just that the dentist needs to understand it. I mean, Phil. I mean, if you fractured a piece of the crown, you're going to have to communicate to the dentist, my access part of the crown fractured. That communication becomes essential. Without a doubt. Let's talk about temporizing. So the endodontist goes in there, creates an access prep, cleans out the pulp chamber, and the root canal is finished. Normally there's cotton placed in there with some temporary. How do you typically approach this? Unless the patient is coming directly. to me from the endodontist office, which is almost never, Phil, I absolutely don't want to calve it cotton temporary because of micro leakage. Just don't want it. So routinely, my endodontist knows that if they're going to place a temporary for me, which I want, they'll routinely close the access hole with a cotton pledget or a pledget and routinely a glass ionomer. So the glass ionomer will help seal the area. That way, when I know. i'm going back in removing a glass ionomer is easy versus a composite is far more challenging so i i prefer an rmgi or a glass ionomer over a piece of cotton or a whatever you want to use in between the gut of persia but i absolutely my endodontists know that i work with cavit is just It's just not what I want because patients can disappear sometimes. You've known this for a month or two. Well, how much micro leakage has happened? Well, that's it. Yeah, that's exactly right. It really depends on when that patient's going to get back to you. But if we don't know when they're going to get back and there's some uncertainty with the scheduling, we certainly want to do something that's more protective because there's nothing like retro bacterial invasion after a root canal has been opened up. You know, that's not what we want. There's different kinds of posts out there. Now, I know back in the day, there was a typical para post. It was stainless steel. There were some issues with stainless steel. Some of them had nickel in it, which some patients are extremely allergic to and sensitive to. But that was the state of the art at the time. And then they went into titanium alloy. And now, where are we with the materials? And which ones do you prefer? What works in your hands? So when I graduated dental school, probably same circa as you were getting your endo degree, what was in vogue were cast gold posts. And the issue with cast gold posts are root fractures. And they're still used today. I no longer use them. I probably use them in the first 10 or 15 years of my career and long gone in my career now. So to me, as I've watched fiberglass and aesthetic posts, Come into the market, we've seen zirconia posts, carbon fibered posts, and traditional fiberglass posts. And I really go with the quality-minded fiberglass posts today. And the two reasons, Phil, is if they're well-constructed, they should have excellent flexural strength. B is modulus of elasticity. And you said it. You were magic, Phil, when you said it. The tooth's got to handle the stresses. The root, which is already compromised, has got to handle the stresses and pass it to the PDL. And there's nothing better than literally a glass fiber post. So the modulus of elasticity of dentin, that closely associates itself with the glass fiber posts. They've created it where it's very close. Exactly. The number's around 20 MPA for dentin. And the goal of a glass fiber post, a well-constructed one, should be around anywhere from 18 to 22 in that range to mimic Denton. Yes. Right. It's mega Pascals. Yeah. Yeah. Mega Pascals. Yeah. Right. So tell us about the system that you use. You can name products if you feel you want to. And the technique that's important. Because we talked about... posts that are very technique sensitive. And when you get to systems that are too technique sensitive, we all know what happens, right? There's more room for error. Compliance goes down. The learning curve for a new staff member that comes on board is more difficult. So we want to keep it simple. So what's your procedural methodology for putting in a glass fiber post? Well, I won't give away the entire webinar, but the procedure basically is an instrumentation. where again, access is critical. So if there's one takeaway from people who can't attend the webinar and are listening to the podcast is when you're instrumenting a canal. So let's say the endodontist or you are now doing instrumentation for a post. You cannot let your orifice or your access opening guide your files. You must let the canal, you must work with the canal. And if the orifice is just too limiting, And now it's guiding your burrs as you go deeper. That's where you really risk fill perforation. So I believe orifice has to be enlarged enough so that you have full visibility when you're removing excess gutter purchase. So if the endodontist hasn't done that for you and or you're re-cleansing the area, let's just call it with Gates glittins initially. And then ultimately you go to the reamers that come with these kits. A size two reamer goes with a size two canal, a size two fiberglass post. So the way I do it, I use my Gates glittons to create my initial removal of my gutta percha. And then I just use a zero reamer, a one reamer, a two reamer, and just go categorically up as I do it. I use electric, so I'm usually around 10,000 RPMs. So that's how I really create the initial shape. And depending on length, I don't want to go too lengthy because I don't want to remove that final apical five millimeters, but I don't want to go too short. So you kind of have to look at the level of the bone. I want to be easily four or five millimeters if possible below the bone so I can flex with the bone and the PDL. And you know that. So all of that goes into it. I'm not overcomplicating it. I'm just going, this is how I determine my depth. Right. And you want to leave a minimum of five millimeters of gut approach at the apical area without a doubt. Yeah. And that is totally correct. Everything that you're saying makes total sense to me. I also use the gates to open, which gave me a feeling of confidence that I'm moving in the direction of where I want the subsequent drills to go because I don't want to push Denton out of the way that's not part of the actual canal space that obviously... Well, in my case, I created, but in your case, the specialist created. What's the biggest misconception of restoring a single rooted tooth? The literature shows the biggest misconception is that these single rooted teeth are not circular. The canals are not circular. They're far more oval. And as you know, they have all these little nuances with each canal with little finger like extensions. So to think that you can take a drill. use a gate scolidin and a reamer, and a file is going to, I mean, and a post is going to fit right down perfectly. I'd say that's the biggest misconception of it. And so canals are routinely just not round. And the clinician has to understand that. And then that leads to how to prepare, how to cleanse, and how to really sufficiently place a long -term lasting post. Yeah, no, that's a great point. And that... that you just made corroborates the thought that a post should not be tightly fitting. It should be gently placed into the canal, like you mentioned. The gap that exists because of the actual shape of the canal versus being circular, we know the post is circular, but the canal is more oval. That gap is filled with adhesive cement, which is good. Back in the day, we used to think that a post has to tightly fit, and that's why active posts, like screw-in posts, in my opinion, are so dangerous because they actually engage the dentin, which is what we don't want. We want the cement to act as that buffer that takes the force to the root to the PDL. Can you make a recommendation on a system that you're currently using? So I think there are some great classical systems out there. So one of them is the Rebuilda system by VOCO. Another is the Whale Dent system. Another system we're working with is the Dentata system. These are three classically excellent systems to use and in my course I'll dive into two of them. We'll talk about why a tapered post more than a pair of posts. I think tapers are, for me, a far more conservative way of doing this. And Phil, I'm so excited to do this on your channel because I'm going to show how to place multiple posts in a large canal and rebuild the tooth. And we'll talk about cores with cement versus cores with core buildup material. There's so much we're going to cover in our hour together. Yeah. And that. webinar that Dr. Graham is talking about is scheduled for Monday, April 10th at 7 p.m. Eastern time. Is that correct, Dr. Graham? I believe so. That's correct. Yeah. So that's Monday, April 10th, 7 p.m. Eastern, 4 p.m. Pacific. The name of it is, Do You Hear Your Patient's Tooth Saying, Save Me? Wow. That's a cool name. That was your idea or you're a producer? I don't have a producer. I'm not that big still. Just a little joke. All right. No producer. We got that right. But you are a great educator, but you need a producer. So it's do you hear your patients too saying, save me? Don't miss it. Scheduled for Monday, April 10th, which is only a few days from now at 7 p.m. Eastern time, 4 p.m. Pacific on VivaLearning.com. And if you're listening to this podcast after April 10th and you missed the live webinar, you'll always be able to get the on -demand version on VivaLearning.com. Just look up Graham. G-R-A-H-A-M, and you'll find the webinar. Dr. Graham, great to hear from you again. Looking forward to the webinar, and we'll talk to you soon. Cheers. Thank you.