The Benefits of Using Warmed Composite When Placing Direct Bonded Dental Restorations

You're listening to The Dr. Phil Klein Dental Podcast from Viva Learning.com. Welcome to Dental Talk. I'm Dr. Phil Klein. Today, we'll be discussing clinical considerations for using warmed composites when placing direct bonded dental restorations. Our guest is Dr. Robert Lowe, who maintains a part-time practice in Charlotte, North Carolina. He publishes and lectures internationally on aesthetic and restorative dentistry. Dr. Lowe, it's a pleasure to have you back on Dental Talk. Well, it's always a pleasure, Phil. I'd like to say hello to the Dental Talk audience again and hopefully can give them some good information on why they should consider warming their composite when they're placing their direct composite restorations. Yeah, and to begin, so what are warming composites, if we can start with that? And can warming composites be a benefit in a high production practice? Well, I tell you, teaching at MUSC now for the last year and a half and seeing these young dentists come out of dental school. with half a million dollars of debt, many of them, and a lot of them going into high production practice situations. Anything I think you can do to increase efficiency while at the same time maintaining quality is a good thing to consider. Now, I think the biggest, at least in my mind, the biggest benefit of warming composite in general is that warmed composite is better adapted to the cavity preparation. What's the number one cause of composite failure? It's micro leakage and secondary decay. And as I've told my students for years and other doctors in lecture, composites are not packable. They're not condensable. This is not amalgam. Composite is like pushing mashed potatoes around in a cavity preparation. So if you think you're taking an amalgam plugger and sealing all these little intricate angles in multi-surface cavity preparations, I think we're fooling ourselves. I always say we fill a class two composite preparation on blind faith because a lot of times we can't see the gingival margin because there's an adjacent tooth and the preparation doesn't go out buckly or lingually enough to be able to see the intersection of the horizontal and vertical walls. So we're just hoping that that round plugger gets into that square corner and squeezes this mashed potato-like substance into that area and adequately fills it. And maybe it doesn't, maybe it doesn't. We can't see that on x-ray. But what we do see is the result of inadequate sealing of those areas, and that is restoration failure. Now, one of my good friends, Dr. John Comisi, who I teach with at MUSC, he often states in his lectures and quotes a study that the average posterior composite lasts 5.7 years. Well, that's terrible. I always say in my lectures that, well, you know, I've placed a few of those in my 40 years of practice, and I don't think the average lifespan has been 5.7 years. But that being said, composites are a lot more technique sensitive than amalgam. They take a lot more time to place properly. When flowable composites hit the market, Phil, It changed the way we work with composite because a flowable material can adapt to the complex geometry of a cavity preparation. The problem with those materials, particularly early on, now there are some obvious differences to those, but the majority of flowable composites were not built to withstand occlusal stress. Yeah, essentially the earlier ones were just diluted composites, right? They were basically diluted composites, more resin, less filler. Right, a lot less filler, exactly. So you could use them in increments of a couple of millimeters, maybe. And, you know, as liners and in small, small restorations and non-occlusal stress bearing areas. The good thing about flowables is they would adapt well to the cavity. Now, when you look at the possibility of using traditional composites. that are warmed that changes the viscosity to make them more flowable like you gain the best of both worlds you get better adaptation to the cavity preparation and you get a better result long term with a material that can withstand occlusal stress-bearing forces so in other words you're saying that we're warming the composite which is advantageous during the application of the restorative material but then once the composite comes back down to regular temperature it has the physical properties of a composite that is more wear resistant and stronger to compressive forces and other forces than a flowable so that's the advantage you're getting the best of both worlds is that the basic concept behind this that is but i tell you you know that people think that warming composite changes the physical properties of the composite or there's the possibility that that will happen and that's that's entirely not true all you're doing really is changing the viscosity so that it's easier to manipulate Warming composite does not affect in any way, shape, or form the physical characteristics of the original composite. So that's where you have the advantage over the flowable. So let me ask you this. Now that we're establishing the fact that by warming the composite, you get the benefit of adaptation, what is the preferred application process to get this adaptation while it's in its flowable state? I think the biggest advantage is just like with flowable composites. It allows us to place the material without having to use a condensing instrument. I prefer unitip, unidose anyways. So, and ADDENT has come out with a new warmer called Compex that actually is like a composite gun. Everybody knows what the composite guns are. You snap the little unitips into them to dispense the material into the preparation. Well, this new composite warmer. actually warms the tip in the gun itself that you're using to deliver the material to the cavity. So you pop it in, you hit the button and within a short period of time that material is heated and then you can go right to the tooth and it literally comes out already with low viscosity so that it adapts to the cavity and you don't put an instrument in to manipulate it in any way. And the big thing too now is when you use a bulk fill composite a lot of times you don't have to layer it so you could use a bulk fill composite in the warmer and use one increment to fill the entire cavity and adapt and just remove the excess around the cable surface margins shape it a little bit and call it a day so when you go back to the high volume practice how much time does that save you it saves you a ton yeah that was one of my original questions about the high volume practice so right I know that some dentists are using warmed, higher-filled composites for cementation of CEREC and similar types of CAD CAM restorations rather than traditional cements. What do you think about that and what are the advantages, if any? Well, I think that's interesting because if you go back in history to one of the first doctors to do porcelain veneers, Dr. Mark Friedman. Mark Friedman used to use traditional composite. to cement or place as veneers because we didn't have flowable composite. We didn't have resin cements. I don't know if he used finger manipulation to thin out the resin composite and make it a little bit less viscous to place. I don't recall his exact technique. But when you fast forward here now for cementation of CEREC restorations or high strength ceramic. you're going to have the benefit of a material, a cementing medium that has higher physical properties than traditional cements. The other thing you'll have is if you have any minor imperfections or gaps or minor irregularities, you've got a solid composite seal. So see nothing but advantages there. Right. So the higher filled composites gives you all the benefits of a higher filled composite compared to one that is not as filled. But because we're warming it, we get the advantages of using it in either a CEREC or a similar type of CAD CAM restoration. I've also heard, and I don't know if this is true, that's why we have you on this podcast and I'm asking the questions, you're answering them. I've also heard that warm composites require less cure time. Now, again, that's something that goes along with a high production practice. That's valuable to a dentist. As far as I know, most dentists are not aware of this nor taking advantage of it. What are your thoughts on that? I'm not particularly... well versed on how it affects the cure time. But I will tell you as a clinician, if I have to cure five seconds or 10 seconds or 20 seconds, I don't care. I want to make sure that things are well cured. My time isn't that cut short that I need to worry about saving a couple seconds on curing the cement. But if that is true, you know what? Just another thing. I always over cure anyways because you can't over cure. The other thing too is a need to stress when we're talking about curing, particularly whether it's warm composite or whether it's composite cement or what have you. Most dentists are unaware of the output of their lights and whether or not their lights are getting to the proper depth. So again, just like any other composite or any other cement, my main worry about stressing a shorter curing time is, are we getting to the bottom and curing everything? Are we curing the top and leaving mush on the bottom? So I don't know. I think there's room for discussion on that. I want good results in the office and I don't shave time just to worry about making things faster. I want them right. So we'll come back to that. Okay. This Compex warming device, does that accommodate all these compules that are out there from the different manufacturers? Is this kind of a universal gun that how do I know that I don't buy some composite where my compule, this unit tip, whatever you called it, doesn't fit in that gun? How does it accommodate everything? Well, that's a good question. And I tell you, I haven't tried every single brand on the market, but I've probably used 10 or 12 different ones. And most of these tips, I would guess, are made by one manufacturer that sell them to the different companies and they load them. They all fit. I've never come across a unit tip that does not fit in the compacts. I don't think that would be something that a clinician should have to worry about. Shrinkage has always been a big topic. It was a huge topic in the past before the materials became more advanced. Now with more advanced materials. It was a big topic on Seinfeld from what I remember once too. I must have missed that. So warming. You have to catch that one. Yeah, right. Warming is documented to reduce shrinkage and shrinkage stress. I assume that has to do with polymerization stress too. I don't know. You let us know. Is this significant to restorative dentistry? Well, I think it's well documented that shrinkage stress are a big deal. They're a big deal to the stresses that are put on the adhesive and the stresses that are put on the restorative material themselves. I mean, just look at the marketplace, how many different companies have come out with low shrinkage or low stress materials because photopolymerization does cause this cross-linking. that in some cases, depending upon the length of the chains and whatnot, and I'm not a chemist, it's going to affect how much the material withdraws, how much it pulls, and how much it pulls the adhesive. So I think it is a big deal, because particularly since micro leakage is one of our worst enemies, you know, bacteria only one micron in diameter, and we consider a closed margin 20 to 30 microns, so do the math. The smaller you can make the gap, between the restoration of the tooth, the better. So, and as far as the shrinkage stress, the stress on the actual tooth structure is brittle. I mean, there's been, you know, studies with older composites that have shown potential cusp fracture and displacement because of polymerization shrinkage stress. So I don't know that it's as big a deal now as it was 20, 30 years ago. It's certainly a consideration. And again, If your goal is to put a stress-free, inert material into a cavity preparation with ease of placement and the best adaptation possible, it just makes sense to use a warm material. Yeah, that's exactly what I was going to ask you as a closing question, Dr. Lowe. I was going to say, if you had to choose one or two main reasons why you would recommend every general dentist to use a warm composite technique. What would the reasons be? You just covered it. So let me ask you something different. Fast forward five years from now, 10 years from now, how long is it going to take for the prevailing method of delivering composite into the tooth preparation to be a warm technique versus the way it is now? Because I don't know what the adoption rate is right now for warming composite before delivery. Well, and I'm not aware of the adoption rate either. That's why we do these things and give the profession the information to consider and give it a try. I'm familiar with a lot of different efforts over the years. I was a big user of SonicFill for years when that came out from Kerr. I mean, that was a very innovative device and a proprietary composite that changed viscosity based on sonic energy in the handpiece. It came out like a heavy-bodied flowable, and it allowed manipulation so that you didn't have to condense and you didn't have to use a flowable as a liner. that's one thing and we talk about cements years ago there was a material i believe it was from premier called sonosem talk about uh old ceric restorations and that this this was a composite cement that used a vibrating mechanism almost like the old condenser condenser i used to use on alloy with a rubber tip to change the viscosity and almost liquefy the cement and squeeze out the excess around the margin so We've been thinking about ways to change viscosity of our looting agents and restorative materials for years. And warming is not a new concept, but I think with compacts, you gain the advantage of having the warm composite right at the tooth. Even with the older warmers that are available, you still have to take the composite comp, you will load it into the composite gun or delivery device. and of course you could fumble it around a little bit if your system puts it in backwards or what have you by the time you get that over to the cavity preparation and actually start delivering that composite how much of that heat is already dissipated that was always the knock on heated composites with the traditional warmers whereas now with compacts that that that is totally gone i mean That material is ready. You go to the tooth and it just comes out and flows and adapts nicely. I don't know if we're going to be changing from a BISC-GMA-based composite resin restorative material in the future or not, but I think that as people discover the benefits, not only better restoration, but ease of placement and delivery, just the fact that you don't have to place in layers and condense those layers. If you're using a bulk fill flowable in a comp fuel and you warm it, it's going to make the restorative process go a lot smoother and quicker and still get a superior result. And that's really the key for me. Dr. Lowe, it's been a pleasure to have you on the show. Great insight. We learned a lot. It's always great to talk to a wet finger dentist who's an academic guy who's been around the block a couple of times. You've practiced a couple of decades at least, I would say. Graduated in 1982. There you go. I stopped counting those decades. Yeah, I know. It's scary when you stop counting the decades. I know. I know. But we have a young audience, too. So we want to make them think we're hip and young, too. To all the young dentists out there, it's a pleasure to be with these young dentists and training them in school and just watching them absorb all this information. But just remember one thing. You can't do everything on a computer. Computer-assisted dentistry is nice. But learn. your basics, because that's where it all starts. Dr. Lowe, great podcast. Thank you so much for joining us and have a great night. Thank you so much, Phil. Look forward to the next time.