Zirconia vs. Emax - When, Where, How?

You're listening to The Dr. Phil Klein Dental Podcast Welcome to the show. I'm Dr. Phil Klein. Today we'll be talking with Dr. Alex Vasserman on the subject of zirconia versus emacs. We'll address his philosophy on material choice and his thought process on prep design, red flags as it relates to materials, and his cementation protocols. Dr. Vasserman has been practicing dentistry on the Upper East Side of Manhattan for almost 10 years now. He is passionate about full mouth reconstruction with a focus on cosmetics, longevity, and predictability. Before we get started, I would like to mention that Dr. Vasserman's webinar titled Zirconia vs. Emacs, When, Where, and How is now available as an on-demand webinar on VivaLearning.com. Simply type in the search field Vasserman, V-A-S-S-E-R-M-A-N, and you'll see it. Dr. Vasserman, it's a pleasure to have you on Dental Talk. Oh, thank you so much, Phil. I appreciate it. We're talking about some interesting things today, indirect restorations specifically, and you have a philosophy on using certain kinds of materials based on their clinical applications. So let me begin the podcast with this question. When it comes to Crown & Bridge, what are your go-to materials regarding aesthetics, durability, and longevity? I try to keep it very simple in my practice. I basically... put my restorations, indirect restorations, into three categories. Aesthetic, adhesive, and cohesive. Aesthetic is going to be anything in the smile zone. Those are primarily going to be adhesive restorations. If I'm not changing the color too much, I'm probably going to end if there's no bite issues. I'm probably going to go to something like feldspathic porcelain or Emax, pressed Emax primarily. It's very rarely that I'm going to do milled Emax in the office. In my practice, it's either going to be feldspathic, pressed Emax, or milled zirconia. So if it's aesthetic, we're talking about Emax or feldspathic porcelain. If it's going to be adhesive restorations, like an onlay, minimally prepped crown, like a three-quarter crown where I have a lot of enamel, that's going to be pressed Emax. But in that same situation, if there's any kind of occlusal issues, someone that is a Bruxer, parafunctional habits. I'm going to go to zirconia. So what do you feel about some of the dentists out there that are kind of using zirconia for everything, regardless of whether there's a physical need for that extra strength? They're just going for it because it's one material. It is aesthetic and it is strong. So what's your opinion on when they say that? Indefinitely. There's some really good zirconia out there. For example, recently Ivoclar released this zirconia, which has the 3Y. and the 5y in it um it's called zircad prime where you have the durability but it's also aesthetic and it's great um i'm a little bit still hesitant about bonding zirconia i do it when they need to for example if i can't have occlusal reduction because of pulpal tissue that's very close i will use zirconia in the posterior And I will bond it using Z-prime from Bisco. It's an MDP-containing material that makes it possible to increase the bond strength from zirconia to the tooth. But I'm very cautious. I'm hesitant. I will let the patient know that this type of material may perhaps come off, so that way I'm ahead of the problem. But there's nothing wrong with it as long as you're following those protocols. I'm just a little bit cautious and I will always let the patient know. So you mentioned posterior when you talked about zirconia. Yes. So if you do have adequate retention and the prep design allows for Emax, you have no problem using Emax posteriorly. Yes. As long as there's 1.5 millimeter reduction and the patient doesn't appear to have parafunctional habits like that crossover. neurological disorders where they're all over the place yes I will use Emacs the red flags to me are typically those second molars where everything is okay but that second molar is kind of beat up I'm very cautious about using Emacs on that tooth in light of the fact that we're talking about tooth preparation design what are some of the considerations that a clinician should be aware of when using zirconia versus Emacs yeah so It all comes down to enamel, right? When you look at the tooth from the occlusal view and you have that enamel ring and you have 1.5 millimeters of occlusal reduction and there's no parafunctional habits, that's where I typically will go to Emacs for bonding strength to that enamel. But if I don't have very healthy enamel and there's parafunctional habits, I will try to go to more of that cohesive restoration where I'm getting the six degrees of taper, where I'm getting four millimeters of ferial to grab onto the tooth, at least four millimeters to try to grab onto it. And I'm relying on those cohesive principles as well as adhesive. So I'm kind of giving the tooth the best case scenario for longevity. Right. So you did mention some red flags. Can you give us a few more red flags that typically you consider as being something to be concerned about that affects your material selection? Yeah. So we mentioned parafunctional habits, that second molar, everything is perfect except for that second molar. Typically, joint and occlusal disease will come to mind. If there's not enough prep height, if you're barely grabbing the tooth, you need... least two millimeters of sound tooth structure and you need two millimeters of some kind of buildup if there's a root canal or some kind of a core buildup anything like that so all together you do need four millimeters of ferio if you don't have those it becomes very tricky the patient needs to know that the prognosis is garden whether it's emacs whether it's zirconia anything like that the likelihood of that restoration coming off is pretty high. So the patient doesn't need to understand that because there's not much tooth structure that one day this restoration will come off. So those are some of the red flags that I typically will explain to the patient. So let's talk about cementation protocol. Again, we're comparing zirconia to Emax. So let's start with Emax. What is your typical protocol for cementing in? indirect restoration using the material emacs so let's say it's a totally adhesive restoration we mentioned that ring of enamel let's say it's a totally flat no retention whatsoever we need to go fully adhesive here which means the tooth on the tooth side of the restoration here i most likely will use a rubber dam we will particle abrate the tooth um selective etching enamel only for 15 seconds we're applying all bond universal from bisco because it's easy it's one bottle it works with different cements uh it has mdp in it we're applying two coats of that i air dry between the two applications we're curing it And then if it's an adhesive principle, I'm going to use my All Bond Universal and my Dual Link. It's an adhesive cement, also from Bisco. However, if it's cohesive restoration, where I have my six degrees of taper, four millimeters of prep height, and I don't really need to go adhesive, here I will just use Therisem. I will particle abrade the tooth. I will load my adhesive restoration, my crown, with thera cem, and I will fit it over. Because remember, here I'm not relying on my adhesive principle. I'm relying on my cohesive. This is the zinc phosphate that worked for generations, forever. And a lot of those restorations don't come off unless it's fatigued, right? So here I will place my therisem. I will particle abrade the tooth. and that's it now if it's zirconia and i'm using cohesive principles the difference is i will apply z prime i will particle abrade the restoration and i will apply z prime which is an mdp containing liquid from bisco i'll apply that to the intaglio of my zirconia crown And I will seat that restoration over the tooth. I will just particle abrade the tooth. And that's it. However, if I'm trying to bond that restoration, the case where I don't have 1.5 millimeter reduction to place an Emax restoration, only let's say have a millimeter, and I need to use adhesive principles on zirconia, I will particle abrade the tooth. I will selective etch the tooth. I will apply my All Bond Universal from Bisco. I will then particle abrade the zirconia crown. I will use Z-prime, and then I will seat the restoration. Okay, so those techniques that you use are pretty set in your office as far as your staff, the materials that you have in front of you when you're doing this. At what stage of your treatment planning in the process of delivering these indirect restorations do you delineate? to your staff, like what materials are you going to be using? My staff already knows. When they see that restoration, they will check whether it's Emacs or Zirconia. They will look at the write-up from the MyCeramist, and they'll know in the lab we have silane. So right away, my staff, the assistant, will apply silane in the lab to the Emacs. And if it's Zirconia, they will particle abrate it. And then I will apply Z prime chair side. So they know what material. So it's easy. It's either going to be silane or it's going to be Z prime. Where are we treating the tooth? And I will never, that's a big never. I will never particle abrade my Emax. If you particle abrade the Emax, there's a high chance that it will fracture. So my staff knows if it's Emax, all they're doing is they're silinating it. And if it's zirconia. they will particle abrade it. And then the rest is set up right in the office. It's a very easy system. It's either Zirconia, Emax, or whenever it's feltsopathic porcelain for the anterior, it's the same protocol as Emax. Right. So tell us, as we wrap up this podcast, Dr. Vasserman, and this has been very helpful, about same -day dentistry for you. Are you doing any same-day dentistry where you're milling directly chairside? We're in the office, we're not milling and only because there's just no room for, we have a very small office, 900 square feet. And I don't have the physical space for same day dentistry. So that's why a lot of it is being sent out to my technician. And that's why whenever it's Emacs, it's always pressed whenever I can, whenever we can help it. um and because we're already sending it out however if i was milling in the office there's no reason why you can't use milled emacs for those posterior cases if it's if if the reduction allows it and there's no red flags right you're on the upper east side so obviously the uh space restrictions are pretty robust over there in manhattan aren't they we're very tight here yeah they sit in my In my, you know, five by three office. How many operatories do you have in that office? We have three ops. It's our hygienist. And then I have two rooms to kind of go between. And we managed to fit, you know, a CT scan and a scanner and all that stuff. So it's all very tight. Wow. A lot of planning to get all that in there. So do you think the future of dentistry is chairside milling? Or do you think that always, in your mind, dentists will be using the laboratory for fabrication? Honestly, I think that there's room for both. You still need the technician. And of course, milling is getting better and better. The mills are getting more predictable. Software is getting more predictable. The burrs are now moving in more directions to create those small undercuts and all those things that we couldn't do before. But I still think that the human experience of the technician... is very important where they can do those aesthetics cutbacks that we just can't. And ultimately, who's processing a lot of the chair side work in the office, it's our assistants. So the technician, I don't think, is going anywhere anytime soon. All right. Well, listen, Dr. Bassman, again, we appreciate all your input. Thank you very much for taking the time and a busy... day in Upper East Side of Manhattan. I was born in New York City, so I know a little bit about New York and it's kind of a hectic place to live and probably practice dentistry. But we appreciate all your help. Great insight. And we look forward to having you on more podcasts and webinars on people learning. Thank you so much. Of course. Take care. Thank you for having me, Phil.