Delivering Zirconia Crowns: A Clinical Discussion with Dr. Marty Jablow

I'm big on using a timer. I don't like guessing on anything that I do, whether that's topical anesthetic, whether it's waiting for the anesthesia to work. I mean, I pretty much have it down and, you know, know the material that you're using. What's the set time? I place gauze over the crown, trying to keep it as dry as possible. Once the buzzer goes off on the timer, you know, we go in, remove the excess cement, floss it, do what we have to. Welcome to the Phil Klein Dental Podcast. Today we'll be taking a clinical journey through the delivery of a zirconia crown. We'll talk about the scan, marking our margins, working with the lab, choosing the right kind of zirconia, and discussing the tools and techniques for seeding, adjusting, and polishing our zirconia crown. Our guest is Dr. Marty Jablow. a popular key opinion leader. He speaks a lot on dental technology. He has a tremendous amount of expertise in chair-side dentistry. He's a sought -after lecturer and consultant to the dental manufacturer community, and we're very happy to have him on our show. Dr. Jablow, thanks for joining us. Thanks, Bill. It's a pleasure to be back. Yeah, absolutely. We appreciate all your contributions you've made to Viva Learning over the years, webinars, podcasts. You've been with us a long time and really appreciate your input. You're one of those guys that are in the trenches when it comes to dentistry. You're doing the actual real stuff. For a doctor to be in the trenches and really know what it's like to deal with the challenges that the typical clinician has gives your insight so much more relevance and credibility that we really enjoy having you on the show. So before we get into the... the techniques and the tools for chair side adjustment of of zirconia which is going to be the bulk of what we're going to be talking about today because zirconia is a very strong hard material and we do have to think about adjusting it contouring it polishing it you're going to help us with some of those those techniques as far as your experience. But before we go into that, tell us your journey in your transition into zirconia and tell us what materials you were using before and how has zirconia treated you as far as success and failures? So let's see. The journey into zirconia was quite a while ago at this point, and it came from mostly a PFM world. And then we were doing some, you know, lithium dosilicate, Emax. and then you know we had to bond it and there was all the steps involved whereas zirconia when i transitioned into zirconia i found that we were getting better results and the results weren't that we were getting bad with emacs the reason was that it was more about how it was a lot similar to pfm we would take it we'd cement it it was all done the same way i wasn't bonding them in And that was kind of how I transitioned. And I found that even though I was taking conventional impressions at that time with PBS, I was getting better fit and finish. I don't know if I realized at the time that many of the labs were scanning. the impressions at that point and then milling it because this was quite a while ago but i think that's what was happening and i was getting better fit and finish for most cases single units small three unit bridges and then obviously we when we transition to you know large span implant stuff that was all zirconia you know i said this stuff is pretty darn strong and I can kind of transition out of PFM. That doesn't mean I don't occasionally do a PFM. There are indications for that, but I would say probably 95% of my work right now is in zirconia restorations, usually either completely monolithic or, you know, using some kind of shaded, you know, what they call Bruxer anterior, katana, that kind of stuff that gives me, you know, a little bit better aesthetics. to the zirconia itself rather than just trying to rely on stain. So with these additional options that we have for our indirect restorations, as far as tooth colored material, we really have to have a good relationship with the lab. We have to know the lab's capabilities. And when communicating with the lab, we certainly want to, in the case of zirconia, make sure they understand our aesthetic requirements for that case. Higher yttrium, you're going to get better translucency. And of course, if we're looking for strength, we're looking closer to a 3Y. So this communication with the lab is so important when we're trying to balance aesthetics and strength. Yes, especially when you're doing, you know, the entire anterior. You know, it's hard to match an Emax crown to a zirconia crown to a PFM. I mean, the materials are so diverse that it's hard to match them very well. But if we're doing, you know, the front eight on the maxillary arch, you know, I can do that in a very nice zirconia, get a very nice result that the patients are happy with and reduce my chair time because it's easier to cement it. then go through a fall, get them bonded and do all of that. So regarding cementation of zirconia, Dr. Jablow, we talked offline and you're a proponent of cleaning the inside of the crown, making sure the tooth is clean, keeping the tooth slightly moist. And then you go in with your looting cement and that's it. You're not a real proponent of meticulous bonding, air abrasion, MDP primer. In most cases, you're relying on the prep. itself, the retention properties of the prep itself and the cohesive properties of the cement. And that's it when it comes to putting in your zirconia crowns. You know, zirconia bond strengths aren't great usually to start with, not like when we get into Emax. So what we're really looking at is back to the bread and butter of what I call preparations, good resistance and retention form. If we've got great resistance and retention form, as they used to tell us in dental school, it doesn't matter what you put it in with. So, you know, I always come back to the preparations. Preparations still need to have certain basics that will apply. I mean, doing those flat top posterior preps and trying to bond zirconia on them, you know, your mileage may vary, as they would say, versus, okay, an Emax crown will do that quite nicely. So, again, like everything else, it's case selection. And, you know, what tooth structure do you have left? What the occlusion looks like? How much room do you have? I mean, all those factors come into play in selecting the proper material for the proper situation. So sometimes it may be Emax. Sometimes it could be a PFM, like I said. And then most of the time for me, it's some version of zirconia. Now, with the additional strength of zirconia compared to what we have been using in the past, are you finding that you're doing less tooth reduction because you're... restorations could come back thinner? Yes, absolutely. You know, when you're prepping the teeth, this comes back to all the selection you do. What burr do you use? You know, it's not one size fits all. If you know that you need one millimeter of reduction and you want to put a chamfer or a shoulder, depending on your preferences, select a burr that's one millimeter in diameter at that point so that you know when you bury that in as a depth cut, you can just pass it around. I use electric handpieces. I set my BNAs to the exact speeds that I want them to, to achieve the results that I need. So if you use the correct burr with the correct handpiece at the correct speed, you can very efficiently prepare a tooth for whatever that might be. How long have you been using electric handpieces? And do you use air-driven anymore? Or are you 100% electric? I've been electric for a very long time, well over a decade. With that, i did used to use occasionally some air driven hand pieces um just to adjust uh you know occlusal adjustments that kind of thing short things just because i at the time we didn't have lots of electric hand pieces so did not have them run through the sterilizer we used them for that. Um, the only time I picked up air recently was because my electric went down and, you know, it took about a week for them to get me what I needed to get it fixed. And once I did, it was, you know, I'm back to full electric. I use the, uh, currently I'm using the iOptima internal. So it just fits right into my bracket table. And I set that to the speeds that I need for the birds that I'm using. Or as I like to call it, especially when we're polishing something with like show food, brownies, greenies, you know, I call them if you over rev them, they're rubber bullets. And if you've ever been hit with one, you know you've been hit because you're not using the right speed. So always look at the instruction sheets and know what you're doing before you do it. So before we get into the details of adjusting zirconia, your tools and methods that you prefer, I assume you're doing intraoral scanning in the office. You're no longer using traditional impression materials. And the other question I have is, are you designing your preps yourself? In the office? Or are you sending that out to the lab and delegating that out? What I do is I'm probably for both fixed and removable and implants, I'm, again, 99.9%. I'm not picking up impression material. That's the last thing I want to do. I want to scan everything. I want a digital copy of it all. So we'll scan the preparation. I personally mark the margins. I think every dentist should mark the margins because they are the best ones to do it. All right. That doesn't mean the lab may not tweak something, but I thoroughly, and I tell all the dentists who work with me, you need to mark your margins. And in fact, recently my new associate who just started said, boy, my preps don't look so good when I look at them on a, you know, on a 30 inch monitor. So, you know, I said, you'll get better. She's just out of residency. I said, you'll get better because you're going to be looking at your stuff on that big monitor, not like we used to look at it in impression material. So I think it leads to being a better dentist because you do better preparations. And if you mark the margins, the lab likes it better. At that point, we don't mill in -house because I haven't seen the ROI really be there. I use laboratories that for the most part, what I call their B2B laboratories. I mean, laboratories have laboratories for labs. So I use some of them because I can get the same results at a lower cost. So I'm in a PPO office, costs matter. You know, we're not getting full fee for service. So with that, I let them design the crown, but I do mark the margins. So when I get it back, it's... much adjusting should i do and if you really spend the time and make sure the bite relationship is good and you've got a good scan there should be minimal minimal adjusting okay so let's say there is some adjusting let's talk about the technique and the tools that you use in your office for zirconia okay so let's start with the thing that may be the first part of adjusting which is Hey, it's got really tight contacts and it doesn't go down. All right. So it doesn't go to place. Doesn't the margins don't meet. So then we're going to mark the the inner proximals. And there's various products for that. Microcopy has a film. Some people use, you know, occluding paper, you know, whatever. Some people market with a Sharpie, you know, whatever they're going to do. You don't want to just adjust with anything. You know, that's really the key here. You want to adjust with something that's going to adjust as smoothly as possible and do it as efficiently as possible because that's going to make your next step, which is the polishing, even easier. So I usually reach for these microcopy Z-class burrs that are made just for adjusting. They come in various size and shapes. Those burrs have, you know, the diamond impregnated in, and it's just not random. They're made to give less gouging, smoother finishes, that kind of thing. So I take that, I put it in my electric handpiece. I run it at 100,000 RPMs. All right. Cause I can set that with my electric handpiece and very feather touch with that underwater. I can adjust those exact, you know, spots. And then we take it back to the mouth. Do I need a little more? Do I not? That's just normal adjusting as we go back in what I call the fine tuning of the insertion process. And that's kind of what we do. Now, once it's fully down and the margins are sealed, when you check the occlusion, now you're back to the normal stuff. So you mentioned, Dr. Jablow, 100,000 RPM. Is there a gear reduction number on that, like five to one or something like that? I'm using that because most people understand their air handpieces. So what you're doing is with my B&Rs, or any electric for that matter, you use a five to one handpiece. So if you're running at 40,000 RPMs, you're running at 200,000. All right. And the same thing happens when you use an implant drill, which is whether it's 15, 16, 17 to 1 reduction, you're never going to get that kind of speed. It's the same process. So green ones are reduction hand pieces when you're in electric. Blue ones are 1 to 1. Most people consider those slow speeds. And then high speeds are 5 to 1s, and you're just adjusting that. But you're looking at the absolute RPMs at that point. And that's what you use for adjusting zirconia when you're doing that interproximal reduction to make sure that that crown is seating properly. Correct. So I'm running it at 100,000 RPMs, which is, you know, at that point, if it's five to one, you do the math, 20,000 RPMs. You know, you're setting it at 20,000, but the thing's spinning at 100. And the burr that you like is a diamond impregnated burr? And what's the shape? bird to use for that they make usually i'm using a feather edge diamond on something like that because i really don't want to take big amounts but again you can use you know whatever you think is appropriate for that kind of you know for that situation which for me on the interproximals that's what i want to use i want a really fine diamond that i can just kind of brush it away You know, I've talked to a lot of KOLs, and it seems to me the popular thing to do today is to use disposable burrs. The added cutting efficiency of having a new burr each time, and the simple fact that you don't have to re-sterilize a burr, which takes up time from your staff, and that costs money. The ROI on having a single-use burr far outweighs reusing a burr, and that seems to be the trend these days. It's really simple because all the microcopy burrs come in single use packages. They're disposable. So we go through that. And like you were saying, once you use it, you know, it's duller. Once you run it through a sterilization process, it's duller. So, you know, I want the most efficient cutting because, again, I want this to leave the least amount of marks possible in my zirconia because ultimately I've got to polish it out. And then when we polish it out, I reach for actually microcopy make zirconia polishing burs that are single use. So we go to those also. All single use, all efficient. We're not cleaning things. We're not sterilizing them. That goes in the garbage can. And I get the best results that way. What we would call, and we're going to get into this a little bit, you know, what we do on the occlusal. But again, polishing it up, you know. So once you finish the interproximal adjustments, the contacts look good. You believe the crown is fully seated. I assume you're using loops, some sort of magnification to make sure that you're visually seeing the margins are closed. I wear magnification. I'm using oroscoptics, the dragonflies. I'm using three and a half and six and a half, I think it is, or six. So I can actually see it. We also take a radiograph to make sure everything is fully seated. I run the floss through the contacts to make sure that's easy. We ask the patient, are they feeling pressure? And a little bit of pressure is okay. I mean, I call it the new pair of shoes. They've got to get used to it. And then if that's all good, now we're going to check the occlusion. We use articulating paper. various different ones, whatever you're fine with, you know, whatever you're used to using, that's fine. Again, with most of these scanned crowns, I mean, there's not a lot of adjusting. There's many cases we put the crown in and there's nothing to do except cement it. But occasionally you still have to adjust things. So, you know, we'll do, we'll run them through both, you know, what I call more of a static, the up and down. I don't know if you could hear me clicking. And we ask them to go from side to side, run up those cusps, you know, inclines. And we'll look at it. And if the patient indicates that it doesn't feel correct, we'll then reach for another burr. So in these cases, again, I'm reaching for a microcopy, you know, Z-class adjusting burr. And I may be using a football or I may be using a chamfer. That's, you know, again, not big ones, but smaller ones to just be able to take down either that occlusal area or that area on the incline where the patient feels it's just not quite right. And we'll go back and forth on doing that, you know, till the patient says that feels fine. But with that, I always tell people when you're scanning, make sure you look, you can flip the model around. So go look on the inside and make sure. that the cusps are fully in the fossa. Make sure it really looks down. Because one of my associates had one that said, she said, it fit perfectly, but it was too high. And when we looked at her scan, it looked like the cusps were good on the buckle. But if you looked on the lingual, they weren't seated. And when we retook the scan, you could actually see the difference. So I always say, along with marking your margins, make sure you look at that occlusion and don't just assume it's correct. especially if you're delegating the scanning to an assistant, then I would say, you know, it still behooves you to spend the two seconds to look at it. And it may save you a lot of time in the end. So now we're at a state where you've totally seated the crown. You feel like as far as the adjustment for the occlusion, you're good. What's the next step? So next step is hand polishing. And there's a bunch of stuff that there's a bunch of research out there that says hand polished zirconia is kinder to the opposing dentition than just the stains and what they do in many cases to save time. So, you know, if you can ask your lab to hand polish your zirconia, you're going to get a much kinder zirconia, you know, in the occlusal situation. So then we'll pick up. you know um again i use micro copies they they make these polishing bursts for zirconia we run them obviously at the appropriate speeds again perfect reason for changing to an electric because you've got the right speed you can just dial it right in once you've dialed it in then you just go through the process of of doing that so that you can get that polish really back on it and you can see it When I'm looking through my loops, I can see that there's no more scratch marks. There's no more all of that adjusting. It's gone. You want to, again, try and do that underwater because you really don't want to heat up zirconia. Because if you overheat the zirconia, you can wind up in a situation where, if you're lucky, it fractures right then and there, and you can put the tent back on. Or if you're unlucky, the patient comes back in a short time period. and the thing fractured. And now that's a combination of preparation, making sure you have enough tooth reduction so that you're not getting too thin of zirconia because too thin zirconia becomes very brittle and it cracks. So with that, all of those little pieces of the puzzle help you to ensure that when you do adjusting of a zirconia crown, you're going to get the best results with, I'll call it, the least amount of trauma. to the zirconia itself and that's a key a key piece of it because again overheating zirconia will lead to future problems so you polish those with water using your electric handpiece and how typically how long would you would you say it takes you to get that polish that you're looking for to get those scratches out after you do the occlusal adjustment minute maybe two again this stuff should be quick because if you're using the right materials Like I said, if I'm using my microcopy sequence through all of this, I'm not getting big scratches. I'm not getting gouges. And then the less of those you have, the easier it is to polish the whole thing. So that's why using one single burr one time, you get that better. efficiency and smoother cut than you will if you're trying to use a burr three and four and five and six or most dentists do until it stops cutting yeah and you're also very aware of cost because you said you're in a ppo environment so you're not one to and i'd say throw things away but you are throwing things away but it's cost effective to you to use disposable yeah it's cost effective because when you think about it most people devalue the cost of doing the sterilization and the cleanups and everything else, because somebody's got to do it. So if you're paying an assistant in my area now, most assistants are somewhere around $30 or more an hour, you know, 28 to 35, that's a big deal. I mean, if they're spending 15 minutes, you know, between throwing in, you know, cleaning it off, throwing it in a sterile, you know, in the solutions, then packaging it, then putting it through, then taking it out. putting it in a box, then it's got to go to the room. We're talking about even if it takes 10 or 15 minutes, you've got to put those costs into what it takes. And, you know, with the cost effectiveness of these burrs, it just doesn't make economic sense. Yeah, it's a far cry from the past because I've told this story before on a podcast, but a friend of mine who's a periodontist who just retired, he lives in Austin, Texas. He bought a practice 36 years ago as a young periodontist. The first day, working in the periodontist office, the same staff member stayed on. So the owner left, he was gone. And my buddy's sitting there doing a prophy, and he takes the prophy cup off and throws it out. And the assistant says, why did you do that? And the periodontist says, because I just used it on this patient. It's a prophy cup. She goes, oh, Dr. So-and-so, that lasted the whole day. And he said, well, how did she clean that? How did he clean that? And she said, He dropped it in the blue solution for whatever and washed it off and reused it. Like the barbershop. Yeah, it sounds just like the barbershop. Yeah. And I always watch them do that. They take the combs out and I said, God knows who preceded me in this chair. I guess you just have to pray a little bit. But the days went with the way like a company like Microcopy, it's such an extreme difference in the spectrum of infection control and efficiency. and you know even when i was an endodontist i would make access preps with with round burrs diamond round burrs we re-sterilize them back then because you know they were expensive 10 11 for a burr and to use it once uh to access it we're not doing precise dentistry we're just burning through the enamel and dentin to get to the pulp but you know eventually you have to go to disposable uh that's just the way to go so once you do the polish you're finished with the polish what else do you have to do before cementation So depending on what you're using will dictate the next steps. So, you know, you can use resin cement. You can use, I use Ceramere because I don't have to prep the interior of the crown. You know, whether that's you clean it out with IvoClean or whether you use, you know, something like that, you know, a zirconia conditioner or sandblasted, you know, all those things. I'm just trying to simplify my situation. So again, if you've got good resistance and retention form, there is no need to bond it. You can cement it. And so most of what we do is cementing with Ceramere. I use Ceramere because it's got a high pH. It starts at above 8, not like most cements, which are acidic. So again, you should have less sensitivity. And I'm not big on anesthetizing patients to insert crowns unless absolutely necessary. And it's not something I do on a regular basis. Then we place it in, you know, have the patient bite on a cotton roll, make sure it's fully seated. And then I'm big on using a timer. I don't like guessing on anything that I do, whether that's topical anesthetic, whether it's waiting for the anesthesia to work. I mean, I pretty much have it down and, you know, know the material that you're using. What's the set time? All right. So for Ceramere, it's two and a half to three minutes. I place gauze over the crown, trying to keep it as dry as possible. And then, you know, once the buzzer goes off on the timer, you know, we go in, remove the excess cement, floss it, do what we have to. That's when I'm using the Ceramere. If I'm using a, you know, some kind of resin cement. Before the final set, I need to be in there with floss in the interproximal, making sure that's clean before it fully sets. Because if it fully sets, anybody who's been down that path knows it's not fun to dig all that cement out. Now, in the event that you do have a case where you have very minimal retention based on the prep design itself, then you'll bond. Then you'll bond the zirconia. Absolutely. Then you want to bond, okay? Then you've got to go through all the steps. If you've got, especially like I call them, those short second molars where there's not a lot of inter-occlusal space, do yourself a favor. If you've got the ability to put grooves in, if you've got to drill a little dimple in the occlusal surface, do anything you can to try and increase your surface area and stop that crown from being dislodged. Again, that comes just down to preparation. But if you've got those really short preparations, you've got to take that into account in what you're going to do. The whole piece of it is treatment planning and understanding what you have to do, what materials you have to work with, both in the crown and the cementation, so that when you do that, you're going to get the best results you can. Yeah, and Dr. Jablow, you also have to pay attention to the patient's occlusion. So if they're a Bruxer... Or if you see that they're, you know, they're clenching their teeth heavy on the molar and you're doing a molar with minimal retention of the prep of itself, then you're looking at a challenging situation, even though you're using zirconia. So you have to be, I guess that's all going to be in your treatment plan, I assume. Yeah, I mean, that's the whole idea is here. Why are you selecting that material? So especially if you got a short prep in a Bruxer, you know, I'm looking at monolithic zirconia. Or actually, if that's the case, if I'm really concerned, I'm looking at gold, you know, some kind of gold because I don't want it breaking because the thing that's going to cost you the most money is redoing it. That's a bigger problem than just, you know, eating a little bit bigger lab bill or something at the time. It's not just about efficiency and everything else. It's really about the outcome. If you can get to that outcome efficiently, it's win-win for both the dentist and the patient. Yeah, absolutely. Amen to that. Have a great night. Thank you very much, Dr. Jablow. You're welcome, Phil. Hope to do it again soon.