Confronting Complex Cementation Challenges

You're listening to The Dr. Phil Klein Dental Podcast Welcome to the show. I'm Dr. Phil Klein. The new generation of universal resin cements combines the function of self-adhesive and adhesive resin cements. This reduces inventory and gives flexibility of increasing the bond strength for low retentive situations, such as short tooth preps. Today, we'll be discussing how to handle complex cementation challenges. and why and when we need to rely on a quality resin cement. Our guest is Dr. Michelle Lee, an active member of the Panky Institute, American Academy of Cosmetic Dentistry, and American Equilibration Society. She is passionate about providing excellent patient-centered comprehensive dentistry to her patients and strives to provide gentle and customized dental care. Dr. Lee, it's a pleasure to have you on Dental Talk. Thank you, Phil, for having me. Let me begin this podcast with this simple question. What is your approach to handling some of the more complex challenges associated with cementation? Well, that's a great question, Phil. And I really hope to distill cementation down today and simplify the idea of choosing the right cement and knowing which one to use. You know, to be honest with you, cements may be one of the most confusing topics for dentists as there are so many different names used to describe cements. And in a recent article that I read, the author tries to break down the cements and he states, quote unquote, in the entire area of restorative material, cements may be the single most confusing topic. So what is so confusing about it and what are some of the complex challenges that we face when cementing our restorations in? Yeah, so let's start with some of the descriptors out there. So the nomenclature can get really confusing and I think we get hung up with the name. Just to name a few, we've got looting cements, we have adhesive cements, self-adhesive resin cements, self-adhesive universal resin cements, conventional cements, contemporary cements, self-etching, self-cure, dual-cure, light-cure, and universal. Honestly, no wonder we are all somewhat confused and we get more confused when we're talking to each other, to our dental colleagues, because sometimes we're not talking the same language. Someone might be saying a brand name, someone might be stating the property of the cement. So perfect personal example for me was when I was an associate, I just used the cement in the bing. It was pink. So I used the pink cement. So I think everyone can relate. So I say that jokingly and I have become more dedicated and passionate about having more awareness over selection of cements. Once we understand the basics of cements, we can ask appropriate questions and then we can pick and choose the best cements that best fit the restorative needs of the case. So I'm going to break down really quick and call it kind of speed dating in that kind of a way and just sharing the key components to help everyone better understand the categories so that when you are introduced to a new product and we talk about all the new products today, we can all figure out what category of cements indent and talk the same language. So where we were is we had... phosphate cements, polycarboxylate cements, we had glass ionomer cements. And basically these are the older cements. They were powder and liquid. There were no chemical bonding. And at times it created pulpal sensitivity. Then the glass ionomer cements really paved the way for us in the realm of cements, but it was water soluble. So out of the research from where we were, We're able to enter the market with new categories of cements. So now let's fast forward. Now we have in the dental market, we've got our contemporary cements, which is broken down into three further categories. Now we have your resin-modified glass ionomer cements, our RMGIs, our self-adhesive cements, and our adhesive cements. And I'm going to go back and say you will hear on the market, you're going to hear self-adhesive resin cement. That is synonymous with self-adhesive cement. Same thing with adhesive cements. And under the adhesive cements, we're going to break that down into a light cure and dual cure. So I feel that it's important to share these concepts. I also want to take one quick step back because now we talked about where we were and where we are, right? But it's critical that in the selection process of cements, we have to understand that preparation design is critical. So with so much more CAD CAM technology, digital design, scanning impressions, milling our restorations. our preparations become highly scrutinized and technique can become highly sensitive. So as I teach the restorative microscope program at the University of Pennsylvania School of Dental Medicine, my mentor and I, Dr. Alan Atlas, we emphasize to our dentists, we emphasize to our students the importance of precision-based dentistry. And that starts with the preparation. Preparation is key. It is... maybe the single most important concept to successful dental restorative outcomes. You know, I want to emphasize we need to have the four to six degree taper. We need sufficient axial wall height. We don't want undercuts and we want smooth, smooth, smooth preparations. Paying attention to your resistance form is critical. So if you have a good preparation, I'm going to graciously say you will have a lot more flexibility in cementation selection. So let me ask you this. You described a lot of categories of cements. So if a dentist said to you, Dr. Lee, I really want to reduce my inventory and I just want to have two cements. Does that make sense today or do you need more than two different types of cements in your office? Well, I'm going to say it depends. And with the contemporary cements now understanding bond strength and the dental materials changing, we can really condense definitely the inventory in our practice. So I'm going to share with you probably the three. most used resin cements in my practice. So first we've got the resin-modified glass ionomer cements, and that bonds the dentin. The film thickness is really thin. It releases fluoride, although there's a lot of discussion around how much fluoride is actually released and the benefits of that, what people are claiming. It's very popular. There's no bonding agent required for the tooth. It's very routine for metal crowns, pores-infused metal. indication for this is you must use this in for high strength or high retention preparations. The other one in my toolbox that I have to say is a workhorse in my office is a self-adhesive cement or what they call self-adhesive resin cement. Same thing here. So any product that you have the word SEM in it, and I know we're all going to go back and we're going to look at our labeling. If it has a SEM in it, nine out of 10 times, it's a self-adhesive resin cement. It has a stronger bond strength than the resin-modified glass ionomer cements. Again, you don't need to put any bonding agent on the tooth. There's no etching. There's no treatment. It's a win because it wins a popularity contest because it's so easy. Right. So you've got a resin-modified glass ionomer, commonly referred to as RMGI, right? Yes. That would be your GCEM Evolve. That would be your Reliax. Resin-modified glass on our cements, yes. Right. So G-SIM Evolve is the GC brand, and then you mentioned the 3M brand. Which one do you use? I love the Evolve. I like the use of the G-SIM Evolve brand. It's just the film thickness is really thin, and the light cure is just very easy as a cleanup. What are we actually looking for in the prep? In a resin-modified glass ion or scent, your RMGIs, you definitely want to have a very high retentive prep. So as I gauge a crown, let's say I'm putting a PFM crown. on tooth number 30, if I put it on and I have to use gauze to remove it, and I'm looking at my preparation on the dye, and it's very got good axial wall height, and there's enough retention, I would feel pretty comfortable putting on with an RMGI. Right. And what's the downside of using the adhesive resin cement? You don't have the fluoride release? Is that what you're giving up to get the added retention? You are giving that up. However, I have to say, in my humble opinion, I think more research is needed in terms of the amount of fluoride is released. I don't think there's enough research out there. So it's probably, again, a really hot topic where people will say the fluoride release in the RMGIs are effective. Some people say it isn't. So again, knowing the material and your preparation design, I think is a critical piece here. Yeah. Now, what about isolation as far as contamination with saliva? fluids. Obviously, it's more technique sensitive to use the adhesive resin cement versus the resin modified glass ionomer. So that's a factor as well, right? Absolutely, yes. And so you have to know your patient, you have to know the restoration, you have to understand the environment. But yes, the resin adhesive cements, whether it's a self-adhesive or if it's just an adhesive cement, needs isolation. And what are you using on the resin cement side, the adhesive cement? So when we go down to the adhesive cements, now, again, it comes in either light cure or dual cure. It's the cement that you get and it's in a big rectangular box with a whole bunch of bottles. And I say this jokingly, but it is a cement that requires you to follow the manufacturer's instructions. And there are more steps. The technique is a little bit more sensitive. Isolation is a strong recommendation. And I do recommend to use what is in the kit and not mix between the companies. In your resin cement toolbox, you want to use for your ceramic crowns, your inlays, your onlays, veneers. So mainly for me, it's in all of my anterior cases. And in this case, you have to decide whether are you going to totally etch? Are we going to selective etch? There's a self etching. So again, now that we're kind of talking the same language, we can talk about, all right, are we selective etching, enamel etching? So in my all enamel bonding, I like to total etch. Now, anywhere I see enamel, I like to selective etch. So with this cement, with the adhesive cements, you do have to apply Denton Bonding Agent. You do have to apply a primer to the intaglio surface of the restoration. And using their step-by -step guide is really extremely helpful because a little bit of nuances in these different cements. GCEM Linkforce has a lot of different... abilities to use a self-cure and a dual cure and a light cure ability. The other thing I really want to make a point in saying is when you're using resin cements, make sure they are color stable. So talking to the manufacturers about amines, amines and resin cement cause cements to change or darken over time. So sometimes you'll find that The dual cure resin cements, great for posterior teeth, but you also want to make sure because they darken over time. So some cements are great, but with the amines in their products, they might not be great for your veneer. So it's really thin anterior restorations because we want those veneers not only to bond, have exquisite bond strength, but they also want to have a color stable cement. You covered a lot of the latest advancements in resin cements. Is there anything more you want to add on what's been done in the last five years that have really changed the game for the use of resin cements? So with resin cements that's out there now and some of the research now, I can't say that I am an expert. I always say I'm authoring my learning. So I think I'll be a student in dentistry forever and I'll be continuously learning and sharing that knowledge. So as I look into these different types of cements, what I want to implement in my restorative practice, I'm a general dentist. I'm a restorative comprehensive. general dentist, I want something that's easy to use, that has a high bond strength, and that's not going to take exquisite amount of preparation on the tooth and do it in a very short and effective period of time. So what's actually really hot right now on the market is this universal self-adhesive resin cement where companies are now coming out with your all-in-one. It's like the Swiss army knife, right? You can use it for anterior teeth. You can use it for posterior teeth. You can use it for any type of restoration, metal, glass, or hybrids. And hence, they're coming out with these universals. So I think right now what's really... going on strong with literature and with research, it's this name universal. Again, talk about getting a little bit more confusing, but we're now entering self-adhesive resin cement and now add another component is they're adding a universal self-adhesive resin cement, meaning that you can use it on many surfaces. Now, would that replace the resin-modified glass ionomer or you would still use the resin-modified glass ionomer for the cases that you talked about earlier? To be honest with you, I use self-adhesive resin cements more than I use resin -modified glass ionomer cement. So in my practice, I could probably phase that cement out given the research and given the effectiveness of the self-adhesive resin cement. So out of all the cements in my practice, for me, I use self-adhesive resin cements more. Right, but it wouldn't be a bad idea to hold on to the glass ionomer component of the cement for those cases. you can't isolate or you have cases where you have severe recurrent decay, high caries risk, et cetera. Exactly. Okay. Yep, exactly. And so some of our older patients, and if we're doing all gold restorations and pores infused to metal, and again, if isolation is challenging, definitely one to have in our back pocket as well. But those three are the three critical... cements, or the three important ones, I should say, is your resin-modified glass polymer are self-adhesive and adhesive resin cements. And watch out because the universals are kind of coming on strong right now. So it is a confusing topic. There's no doubt about it, but you did summarize the different categories of cements and try to give us an idea of what our options are. And the question is now, how long do we hold on to what's out there today? Do we make a complete... conversion into this one universal cement that could do everything or purportedly do everything. But again, like we mentioned earlier, the glass ionomer components have been around a while, many years now. They work very, very well, but they are soluble. They do tend to wash out, but the resin modified glass sonomers don't, right? They've added that resin component to keep that. washout to a minimum. Exactly. And that resin component in the RMGIs is what's causing the dentin bonding. So now we've got this glass ionomer. And that's why, as I stated in the beginning of my podcast, glass ionomers has really paved the way. It has really opened up a lot of research and allowing researchers to understand the benefits of now resin bonding. So it's great. And what's really on the market now that I think you'll see more of this is GSM1 product. I've also just recently saw Reliax Universal. So those are the universal self-adhesive resin cements that are out on the market that I think we should watch out for and read the literature, make sure we're talking to our reps, understanding the products before we use it. But again, I can't emphasize enough how preparation design is so critical. So that's key. And then with the knowledge of understanding the nomenclature, we can then pick the tools in our toolbox. I would just love to close with the idea that we sometimes get really hung up with the type of cement, which one to use, when to use it, when in actuality sometimes, as you were saying, Phil, we were using zinc phosphate for the longest time and we could not take the crowns off of the teeth. I want to really emphasize that preparation design is really critical and that we understand that tooth preservation, conservation of tooth structure, knowing our patient and knowing exactly what type of restoration is going to require specific prep design. So as I teach at the dental school, as I teach and see other preparations in other education venues, I sometimes say, where's the tooth? And I say that in a joking way, but I also want to emphasize that I think it's important that we really pay attention. the individual that we're treating, the type of design, and we understand we should know from the beginning exactly what kind of preparation we're going to be doing before that patient, before that person comes into the practice. That way we need to plan ahead and so we can have great restorative outcomes with success cementation. Thank you so much, Dr. Lee. It's really amazing to have you. Thank you. It's my absolute honor to be here. Thank you so much.