Zirconia Cementation: Steps to Simplify Delivery

You're listening to the Phil Klein Dental Podcast. Zirconia is quickly becoming one of the most popular materials to use for indirect restorations. So it's important to understand the process of cleaning, cementing, adhesion, and using zirconia primers. So to tell us all about it and clarify some of the confusion is our guest, Dr. Todd Snyder. He's a popular speaker on VivaLearning.com, cosmetic dentist, international author, lecturer, and consultant. And he hosts a weekly podcast program called Delusional, Winning the Weekly War of Dentistry. If you want to reach Dr. Snyder, you can reach him at legion.dentist. Dr. Snyder, it's a pleasure to have you on the show. Thanks, Phil. Always a pleasure to be here. Good times. So we're talking about zirconia today. What are the different ways to currently cement zirconia? You know, if we got an hour, we got a lot to discuss here. There's obviously traditional cements that you could use. You can use modern bioactive cements. You can use dual-cure resin-based systems. You can use self-etching dual barrel resin cements. And then you can also use, depending on the type of zirconia, you can actually nowadays do light curing of resin and adhesion through them as well. So you've got a lot of options. So a lot of confusion these days. Yeah, it seems like the more options we have, of course, it gets more confusing. And even to add to the confusion, there's the concept of adhesion versus cohesion. Whereas when you... through a full adhesive protocol, it's considered adhesion. And of course, when you're just using the cement as a looting agent and you're relying on the prep itself for retention, then it's more on the cohesion side. What are your thoughts on that? For me personally, if I'm delivering a crown, I kind of just think I'm cementing it. And so I guess it's to each his own on what they describe it as. Hence, I said, cementation can be using traditional cement and cementing could be using adhesive types of materials. Because some of the adhesive materials nowadays are so quick and easy, it's almost the same as using a cement. So it depends on how you want to define it. I lumped in everything as one. So if some people like adhesion different from cement, then yes, there are obviously two one way and three the other. So let's talk about the delivery of the crown to the prep. So when you're placing a zirconia crown, what are some of the challenges dentists typically face? You know, I'd say the number one thing I hear from people is, you know, that their crowns come off. You know, just from lecturing all over the place, doesn't matter if we're in Canada, America, what have you, that, you know, hey, I get zirconia crowns coming off. And so the confusion is, well, how do I put these things on and get them to stay? And so... simplify things, you could say, well, you know, traditional cements, if you have good preparation design and good actual wall height and taper, you know, traditional crown can stay on with literally like, I hate to say it, but saliva sometimes. And so if you have that good of a prep and that good of a fit, you don't need that much, you know, adhesion. Hence, cements work extremely well, you know, whether it be a traditional glass on them or cement or, you know, moving into newer bioactive cements. Things like, you know, TheraSem. Ceramere from Doxa. There's Activa from Pulp Dent. There's a few different types of cements nowadays that you could say, okay, that's simplified enough if you've got the right preparation. But a lot of times you might not have the right preparation, so you've got to have in your bag of tricks some type of adhesive capabilities, and then it becomes even more confusing. So talk to us about your thinking process when it comes to selecting the right. cement. So, you know, you're going to be doing a zirconia crown. How do you approach this? So when you're ready to go and do the cementation, your staff is all ready and your setup is correct. Yeah. So in my mind, you always work from the end goal backwards. Like if my end goal is I'm going to cement this crown in a couple of weeks with traditional cements, like glass onomer or Therasim from Bisco, you know, like something like that. Then I'm thinking, okay, I need to have at least, you know, four to six millimeters of axial wall height. I want a six to eight degree taper on the two. So things fit really snugly. You know, I want things to fit so well that I almost don't need something to hold it in place that the preparation design does that. So if I have those criteria met and I'm not. worried about isolation being a huge factor, then I can use traditional cements. If I don't have all those items, if I can't have the ideal situation, then it means I'm going to have to think differently on my preparation design or my delivery is going to be different. So I'm always thinking with the end in mind, and that determines what I'm doing on the day that I'm actually working on the tooth, getting it ready for preparation, impressions, temporaries, et cetera. So you mentioned that in some of your lectures, dentists say that their zirconia crowns are coming off. That seems to be the prevailing. most common problem among dentists that are using zirconia. In your best guess, what do you attribute that failure to primarily? Well, you know, obviously I'm not standing there looking over their shoulder when they did the preparation design. So my assumption, again, we're assuming here, that everything typically boils down to technique. As much as we don't want to blame ourselves, our beliefs is that we're all amazing. Let's face it, at the end of the day, we're dentists and we do have problems, but most of us won't admit it. And so... What I'm finding for a lot of them is a technique error, whether it's a technique in the preparation design, whether it's technique and using the various types of cements. You know, there are a lot of tiny little details that go into placing things that oftentimes when I have at least a conversation, I find something, at least one aspect that they didn't do correctly. And so it's like, well, try that one thing and maybe it's going to hold up better the next time. What is that major thing that you've been finding? Preparation design, I hate to say it, but I think a lot of dentists believe that many of these newer materials are supposed to be crazy adhesively strong, and they just think that if you just put it on, it'll work, and that isn't the case. But the other thing is the technique of holding things in place, letting them harden for a certain amount of time, making sure that the tooth isn't bone dry, but it's also not overly moist, and there's not a bunch of saliva or blood contaminants. There's a lot of different things that go into it that I think sometimes... the belief is, hey, I can just slop this in and I'm good to go. If we're talking about true traditional cement materials, adhesion is even more challenging because there's way more steps and way more difficulties that can happen. What's interesting, Dr. Snyder, is I'm still hearing that from respect to dentists, that zirconia is not a great material to bond to. But on the other side, there are many dentists who publish and know what's going on with the research. And they say that you can achieve a really good bond with zirconia as long as your technique is really Good. Yeah, I'd say that's a lot of it. You know, definitely technique issue is a problem for all the dentists that believe you can't bond in Zirconi, which I still hear a lot of that. And I think a lot of it is the understanding that, hey. In the beginning, we had a lot of failures. We didn't understand it as well. We didn't have as many great materials as we do now. And so because of that, the belief system is still, oh, that doesn't work. It's like, well, no, it didn't work as well in the beginning because there was a lot of user error and not as great of materials. But things have progressed to the point now where we can get phenomenal adhesion to zirconia if you're having a good technique with the right materials. You can't utilize the same material for, let's say, traditional ceramics. as you would use for zirconia. You actually have to have a separate line of products to some extent to clean as well as to, you know, treat the zirconia. And then you can use traditional resin cement. So there is a definite difference that you cannot use the same technique for both. You will have failures if you're trying to cross the same material, you know, ceramic and zirconia. Yeah. So you mentioned cleaning, which is my next question. So I'm glad you brought that up. What type of cleaning needs to be done both before and after? trying in the zirconia crown you know that they've shown that there's really probably three different ways you could go that are basically the same you know so it's kind of which way you want to go. If you want to, you know, have a sandblaster in the office and use that for certain things, it makes a little more of a mess and whatnot. That's one way to go. You can obviously treat your zirconia restoration with some type of zirconia primer before prying, and then it's easier to clean. Other people would say, well, I'm just going to try the zirconia in, let it get contaminated. and then clean the zirconia and then put my zirconia primer on there. So you've got three different ways you could treat things. It's kind of dependent upon which way you want to do it in your own individual practice. How do you typically do it in your office? You know, I think it's a personal preference to some extent. Me personally, you know, my labs are going to sandblast it for me. I'm going to put my zirconia primer on the inside of it. And that's going to help protect it, but also create the adhesion to the zirconia. And so when that zirconia primer gets contaminated with phosphate or phospholipids from the saliva, I can clean that off and then go back in and cement things in. But for the same token, say, well, how about if I just put the restoration in, keep it simple. I know I've tried it in. I know it contaminated. Let me just clean off all the phospholipid contaminants with like a Zirclean zirconia cleanser. And then I can put my zirconia primer on there. And then I don't have to worry about anything. It's a simple process. Just try it in, get it dirty, clean it, put your primer on, done. I would say that's probably a simple, fast way for most people to go, okay, it's effective and easy. Are all zirconia cleaners pretty much the same? Or are there any particular products out there that offer more than the other? You know, that's a great question. There's three that I know of. IvaClear has it, IvaClean. Karare has their Katana cleanser and then Bisco has their Zirclean. And all three of them are uniquely different in their chemistry. Obviously, you know, I do a lot of work with Bisco, but I've tried all of these different products. I would say kind of depends on the research you read. I'll put it that way. And not just listening to the marketing beliefs of, hey, everyone's product does a great job. So in that sense, I kind of like I lean towards the Zirclean from Bisco, but I really like. You know, as a second favorite, Karari, their Katana cleanser is nice that I can use it in the mouth. So if I have some kind of zirconia repair, I can use that in the mouth. So once you've cleaned the zirconia with the Zirclean, what do you do now as far as the primer? Yeah. If you think of traditional ceramics that we've all placed for many years, you know, your typical inlays, onlays, veneers, et cetera, you know, you would typically place a silane. And so this is where I think some people have a problem that they're using the same silane they would use for traditional ceramics. They use that on their zirconia and it won't work. And so if anything, you're definitely guaranteeing the fact that you're going to have a bond failure because the silane is not going to chemically adhere to that zirconia. And so what you really need to have is some type of zirconia primer. So a zirconia primer is kind of like the step brother to silanes that we'd use on ceramics. the stepbrother zirconia primer can only be used on the zirconia to create that adhesion and so like for example bisco z prime plus it's you know an mdp based chemistry that allows you to adhere to the zirconia so you have to put that on as your first layer that primer layer that chemically connects to the zirconia and then your resin looting agent whatever that is then will adhere to that primer that we had just placed onto that zirconia crown So as we wrap up this podcast, Dr. Snyder, I appreciate the input. It's been very good. Can you give us a brief overview of the steps in delivery of a zirconia crown? Not a problem. Obviously, you want to try a new restoration, make adjustments, polish. And then for the same token, your tooth has to be cleansed, cleaned from any debris and contaminants. Now, you should also check from your laboratory to make sure that they're sandblasting it before they deliver it to you. So you want to just call your lab. They probably are, but I hate to assume. Then from there, you try it in, you contaminate it with the phospholipids from the saliva. You want to decontaminate that surface of the zirconia that you're going to adhere to. You're going to use some type of zirconia cleanser. As I mentioned, I use Zirclean from Bisco. After having used that following the manufacturer's instructions, you rinse that off. Then want to apply the Z-Prime Plus or other ceramic primer to the restoration. And then you can start your adhesion process on the tooth and putting your resin looting agent inside the crown. So what's your feeling on zirconia crowns based on your track record and what the research is showing? If you stay close to the proper technique, what are we looking at as far as how long these last? And I know that's a general question because each case is different, but generally speaking. Well, yeah. I mean, if you think of it being chemically done the same as all of our dual cure resins for onlays and veneers and things, I would hope to get, you know, 20, 30 years kind of thing. So we were actually having a discussion the other day. We're kind of scared for the younger generation that they're going to have to take off some crazy restorations that are bulletproof in the future, that someone needs to come out with a laser or handpiece that goes through these faster because it's going to be scary. Yeah. You'll be long retired though, right? That's the plan. Hey, listen, if you could do dentistry. with the promise to the patient that you'll be long retired before that thing comes off and someone's going to have to saw it out of their mouth, then they should be a happy patient and you should be a happy dentist. There you go. All right, Dr. Snyder, thank you very much. We'll talk to you on the next podcast. Really appreciate it. Thanks so much. If you're enjoying this podcast, please leave a review or follow us on your favorite podcast platform. It's a great way to support our program and spread the word to others. Thanks so much for listening. See you in the next episode.