Injection Molding Technique: A Viable and Affordable Alternative For Full Mouth Rehab

You're listening to the Phil Klein Dental Podcast Injection molding. What can it do for your practice and how can it be a perfect fit for your patients? No pun intended. To tell us all about it is Dr. Tal Wilkins, a dentist who loves this technique and uses it often. He says that his patients can get a full mouth rehab at a third of the cost of veneers. Dr. Wilkins maintains a private practice in Aiken, South Carolina. and is a visiting faculty member and serves on the Board of Advisors at the Pankey Institute. Dr. Wilkins, thanks for coming on the show. Thanks for having me, Phil. I'm glad to be here. We're all looking for more efficient... uh cost-effective ways to do things certainly that would reduce chair time but also come out ahead of the game when it comes to clinical outcome and i know injection molding is becoming more popular now so to begin this podcast tell us what injection molding is briefly then i'll be really interested in hearing why it's becoming a more popular type of treatment Injection molding is something that I've been doing for probably the last three and a half, maybe four years now, where you take a wax up. Like if you have a severely worn dentition or you're wanting to do veneers or something, you take the actual wax up from the lab, then utilize a clear PVS matrix. over top of the wax up that you can then take to the mouth and simply use some of the newer flowable composites to inject into that area. And it basically just surrounds the tooth and you're able to duplicate the wax up in the patient's mouth very efficiently and easily. So why is it becoming so popular? What are the key advantages of this? One of the big reasons it's gaining in popularity is the ease of use. Suppose we're going to be doing some composite veneers for a patient. You know, typically in the past, the way we would do that is we would actually have a wax up done by the lab. Or if you're very good doing that yourself and then that wax up would then be. utilized to make a lingual matrix out of a pvs putty material and then you would be able to take that to the mouth and create a lingual shelf and then on top of that then you would actually then start to layer your composites and finish it at the end and so essentially the only thing you're using from the wax up that this skillful artist at the lab has done with your wax up is just the lingual portion of it and the contact points. The rest of that is going to be up to you as the clinician. And honestly, when it comes to doing cosmetic dentistry, the most important thing is shape and the silhouette. That's the main thing. And next is with the silhouettes, the line angles. Well, with injection molding, you can duplicate every bit of that, whether it's the lingual, the proximal or the facial service. And that's what the actual patient and the public is actually seeing. And so that's what makes it. really a good thing these days. Another advantage is, and where I'm utilizing this is in full mouth rehabilitations. You're actually able to utilize this to stabilize an entire arch of dentistry in one or two appointments. And so you can basically just really without removing any material from the patient's mouth other than just rounding corners so you don't have a pinch point to break the material, where you can actually, in a sense, do a full mouth rehabilitation. And then you can come back later over a period of time and actually swap out these teeth for more durable porcelain material. And you can do it to meet them where they are for their time, circumstances, and even finances. Right. So it's certainly a more affordable procedure you're saying for the patient. Absolutely. Okay. So that's one benefit to the patient. And as far as chair side time, what are we looking at to do some of these cases? I will typically do an entire arch in just one setting, you know, and that could be two, three hours with that. And, but like, you know, if you're doing cosmetic dentistry, if you're doing the anterior six or the anterior eight, that's just one appointment. It doesn't take you very, very long to it. The actual injection molding. doesn't tape real it's the finish work you know making sure this polished really real and especially interproximately because that's where the two types what's where the composites are going to be meeting and generally we're utilizing teflon tape so you don't stick the teeth together so you continue to floss and you know it's hygienic but that's where a lot of the cleanup occurs additionally um and we'll talk about this is a lot of the times the wax ups that i'm doing are digital and so you're going to then 3d print the models that you're going to use for that well Unless you're utilizing the highest setting, you're still getting the little lines that kind of come with 3D printing. Well, that's going to show up in your injection molding because of the PVS material will pick that up as well. And so it's just, you know, you're going to have to finish that as you go along. Take us through the process of creating this restoration using injection molding. Start from the first time the patient comes in for the first visit. Talk about the teeth that you're going to be treating, what the goals are. What is the process? Go back to where you're meeting the patient. And I've actually had patients who had come to me thinking their mouth is hopeless, that they were not going to, you know, it's time to have them all extracted and have dentures placed. And, you know, after looking at it, you know, the bonus sound, you know, they do have a lot of wear on the dentition, you know, various types of. material placed in there. But I talked to him. I was like, if we could actually buy you some time with this and maybe stretch it out to where we can do a full mouth rehab over four, three to four years, instead of all at once, I was like, would you like to possibly keep your teeth? And the overwhelming majority of my patients have said, yes, you know, like, let's give this a try. And, you know, I almost consider to say, if you're talking what the cost of a full mouth rehabilitation is, I almost can do this at a third or maybe even a fourth the cost of what a full mouth rehabilitation is but you're actually doing that the thing is we don't know how long these materials will last and i will tell you it's lasting a lot longer than i thought um with with very very little wear and you know the luster the shine that you get still looks good but once the patient decides that they're you know and we decide they're a candidate for it and that they would like to go along with this, then we're going to start with an ideal wax up. And sometimes I'm opening the vertical dimension. I'm opening the bite. And all of this is, you know, I'm going to utilize the principles of smile design and global diagnosis. Where do these teeth need to be? And from that, I'll then send to my lab. I'll have them do a wax up or I will perform a wax up myself. I do a lot of things in ExoCAD. And so I can then do the full mouth wax up. And then I will save that full mouth wax up as an STL to be printed out. I will then take that same full mouth wax up and then deselect every other tooth in the arch. So say like six, eight, and 10. And then you're going to have the other teeth are going to actually be the full wax up. I'll then save that as an STL and then can print that as well. So from those two types of thing, I will then use a clear PBS. bite registration material and what i'm using now is gc's exa clear it's what it's called but it's a completely clear material and there's several other ones that are out there and i will make impressions with a clear impression tray of the two different wax subs from there you'll then punch holes through the teeth that are going to be injection molding and so the one with every other tooth the full contour teeth you put the holes through that and the other full mouth wax up you will then put the holes through every other tooth that you didn't do the last in the last um wax up from there you actually take it to the mouth and do what i um in a webinar or that i have coming up soon it's a 12-step process but it involves like shaping the teeth, edge prime bond and all those things. But then you'll actually place the syringe through the clear PBS matrix and simply inject all the way down and it will just, it surrounds the entire tooth all the way to the very, very end. And you'll actually do that with all of the teeth in the arch. You'll cure it through the clear PBS and you'll remove it and then do some cleanup, especially in approximately and then go from there. One thing I failed to mention is you actually, put Teflon tape in between the teeth or around the teeth not being injection molding. And that way you're not bonding to the adjacent tooth. And that's where a lot of the cleanup and a lot of the difficulty lies with this procedure is getting the Teflon tape through there nice and flat without the wrinkles and folds in it. And then once you've done the every other tooth, you'll come back and do the remaining teeth with the Teflon tape around the teeth that you just did the injection molding with. And then you're just going to be finishing it like you do normal composite and adjusting the bite and make sure it's working well. And you can essentially in one or two appointments do a full mouth rehabilitation where it's going to work good and last. And then from there in the full mouth rehabilitation range, you can essentially swap it out for a more durable porcelain one tooth at a time if you wanted to. You know, to where you can meet the patient where they are for their finances, their time, circumstances, temperament, whatever it might be. But it's a way where I've been able to get my patients to go towards better, more comprehensive dentistry than, you know, just a single tooth dentistry like I used to do in the past. Most of this restorative work is on the anteriors, I would assume, right? You're not going back in the molar area. I can go back in the molar area as well. It's just a little bit different. You're going to have to have a couple different holes where it pokes through where you can place a syringe. I usually put one hole in the buckle and another hole across the tooth from it as a way for the air to escape as the rest of it's going in that area. I don't do it as often in the posterior because unless you're opening the bite a lot, usually there's not enough room. I also, I'm playing around with 3D printing overlays where it can sit right on top of what is there. But the biggest thing is having the adequate amount of thickness. But you can't do the injection molding on the posterior as toppers on the teeth themselves. Yeah, and I wanted to ask you about the thickness. So we're using a flowable composite to inject into that matrix, that clear PBS material. We're using a flowable. So when it gets kind of thin, what's the risk of fracture at that point? And are you seeing any fractures? Yes, the only failures I've had with that are where I'm violating where it's just getting too, too thin in some of the areas. But some of the ways that I get around that is with my lab, I tell them to do the wax up additive only. Okay, I want them to add only to the wax up. And then I tell them even especially in the anterior on the facial to please bulk up an additional 0.2 or 3 millimeters, which they can just push it out. with the digital thing mediums that we're using these days um and from that then i will look at some of the areas because if you take a look at the digital wax up you can get on you know the phone with your lab and you know do a the computer and look at it together and you can see some of the areas through a cross-sectional slice where it's getting a little bit thin and so some areas you may need to do a little bit of reduction So you have adequate thickness. And the other thing is, is rounding it. You want nice, smooth, rounded edges, no sharp corners. And so that's a bit, especially with my wear patients. I will, you like a sandpaper disc and just kind of round all the edges. Of course, make sure any little areas of decay are gone and you can just kind of add back to it, but it'll just flow and fill into those areas. And as long as you're doing that, it works very, very well. How much occlusal adjustment do you need to typically do after you? finish with all your injection molding? You know, it's really kind of dependent on the upfront that I've done. You know, if I've really, really worked out all the details and the wax up, and that's including digitally putting on a digital articulator and going through that, it's really not that much. It's kind of been amazing to me, and especially... or higher quality labs that understand occlusion, that really understand occlusion and what's going on. And, you know, if you give them a face bow and you give them a, or a DFA or, and also a protrusive bite, that's really, really important for the cusp heights and the posterior to have a protrusive bite so they can set the condylar inclination. If you do all of those things properly, there's very, very little adjustments that you have. I mean, of course, I'm going to go through and do a full mouth equilibration on any one of my patients where this is going, but it doesn't take very, very long. Right. So you're essentially setting the VDO digitally, right? Before you even, you know, virtually. You can do that virtually. What I have found is the best thing to do is to do it with a leaf gauge in my practice. So as I'm taking the scans, I will, you know, and sometimes it's kind of arbitrary, but I'll take a look at the facial thirds, how much wear they have and where the tooth needs to be. And I'll just utilize a leaf gauge in the anterior and I will then scan at that. at that position so i'm setting the where i want the how much the video to be open and where the bite's going to be because you know what's better than the real patient themselves with their their own articulator so i'd rather get that scan and just have the lab set it to that versus digitally opening it up because i think there's more variability there so when it comes to the flowable material that you're actually using dr wilkins i know you're a fan of genial universal um Is there any particular reason that a particular flowable should be used over any traditional flowable? Yes, absolutely. And to my knowledge, and I may be wrong about this, and I do know some other companies are trying to come out with their own brand of this. But right now, GC's Genial Universal Injectable is actually made for this. It started out years ago. It was called Universal Flow. What they found is the majority of dentists are starting to utilizing it with the injection molding. And so they've rebranded it. And actually, they've changed out the one syringe that they had to four different types of syringes. Some is like class two bases. Other ones, a little micro fill. But the biggest thing about... The universal injectable is it's highly filled, like very, very highly filled. Because of that, it has the strength of packable composites, has the strength and durability, the wear resistance of packable composites. And so it's truly a revolutionary product. And to my knowledge, there's not another one out there that's the same as that. So that's what I'm utilizing exclusively. Now, you haven't been using this technique long enough, I assume, to really say what the lifespan, as you mentioned earlier in this podcast, of these rehabs are, this full mouth rehabilitation. So we don't know if we can get five years out of it or do these things start to need a little... loving care one tooth at a time they start to show some degradation because they're really direct restoratives they're not veneers right what's your what's your feeling about how long you think these are going to last based on the experience that you have like i said i have some that are out there for a good three almost four years now and they're working great you know and and some of the anterior work like the composites you know it's not really that much different than a hand layer composite veneer so i'm not really too worried about that too much. But for the patients that are utilizing this for the full mouth rehabilitations, it's kind of a funny thing what I've seen happen. I'm not having to wait that long. A benefit from it is when the patient sees what it looks like, what it feels like, or is it's built a lot of value into what we're doing for them. And I've actually had patients start to swap these out a lot quicker. and earlier, like as in sextants, like the lower left sextant. And most of them are doing the posteriors first, and I try to encourage that. you know leave the anteriors for last but i have um just the other day i had a lady in like three and a half year follow-up she's already swapped out the posterior regions for all porcelain crowns but the anterior is still what we did many years ago and it is beautiful it it's it shines the i don't see anywhere facets on it but she has you know really good crossover anterior guidance it's working out very very well for us so like In my practice, in my hands, I haven't had patients take that long to go to the next step because, again, I believe it's building the value, much like a trial smile in your practice does, but they're actually wearing this one home and they're living with it, and it's working out very well. And even before that, it all comes down to just making agreements with my patients when I'm trying out new things and different stuff. I tell them, you know, We're going to try to go along as long as we can with this. If it breaks or you have something, I'll simply redo that one tooth at the same fee that I gave you last time. And I was like, and I'll continue to do that as really as long as you want me to because it's so quick and easy to do that it's not that big a deal. And I just kind of hold on to their matrices in my lab and just kind of pack it away. And I just tell them, or you could at that point in time, if something breaks down, maybe you want to go ahead and swap it out and we can do a porcelain crown just like the one that you have. And so I believe a lot of times it's just having that agreement with the patient ahead of time. And, you know, things work out a lot better. Yeah. And I assume there's a billable code for this, for insurance? What I have been doing is just billing it as, I don't know that there's a code for injection molding, but it's just more like a composite code. So you could decide whatever works best for you. A lot of times I just call it a buildup and I'll utilize my buildup fee. And actually what I have done is increase my buildup fee a little bit for this type of procedure, but sometimes I'll utilize that. Yeah. And being a very conservative approach to preserving tooth structure. And not charging the patient an arm and a leg for all the veneer work that you would need. It seems like it could also be a practice builder. Absolutely. Absolutely. And, you know, it's interesting. I do the majority of these cases with no anesthesia. I don't have to. You know, if you're getting in there and you're getting a little crazy with your handpiece, you know, around the... the gingival areas are interproximal. You know, you would maybe want to numb a patient up, but most of the time I'm just smoothing edges. Like if I have to remove some decay in areas, of course I'm going to be numbing in those areas, but I've done full mouths like this without numbing the patient at all. They put it in, they come in one day and then they leave the next. And like I said, I'm getting older now. I don't want to have to do the entire mouth. It's a lot. It's a lot to do. But I will still do, say, the upper arch one day and then have them come back a few days later to do the lower arch, especially if it's so different how we're changing things. But generally speaking, I don't have too many problems with it. Like I said, the small amount of preparation that I'm doing is just around the sharp corners from the wear or broken spots. And again, I'm doing it without anesthesia, and it works out pretty well. They're kind of amazing, and it's a big practice builder. So in closing, Dr. Wilkins, this has been very enlightening to hear how you take advantage of injection molding. Are there any other advantages to using injection molding technique in your practice? For the anterior composites, it's wonderful. For the full mouth rehabs, I think the biggest advantage of it is to meet a patient where they are. in their life. And so whether it be the timing in their life, their circumstances, their objectives of what they want to complete and their finances, that's the beauty of this. And you know what? Sometimes we, you know, if you were to do this and say you wanted to leave a patient in temporaries, full-mouth temporaries for a while, technically as a doctor, we have to finish that. And if they decide they don't want to do anything else, like... do you go with that? Well, when you're just actually just applying directly to the tooth with some composites, I mean, you've done what you're supposed to do. The patient leaves, they go somewhere else, whatever. Well, you don't set yourself up for medical legal issues with that. And so that's one of the big reasons why I prefer this technique over prepping all the teeth and leaving them in long-term temporary crowns. There's just a lot of things that can happen. Like I said, life happens for people sometimes. And so I think this is a good reason to utilize this technique. Yeah, I think it's a fantastic service for your patients and for the profession in general. The key thing is, of course, is being careful with your adhesive dentistry prior to this whole thing. Absolutely. Yeah. And we do have advanced materials with dental adhesion, which I'm sure you follow very stringently. And as you know, as a restorative dentist, you know that. without a doubt how important that is. And apparently you've been doing it well because your success rate is speaking for itself. Dr. Wilkins, thank you very much for your time. Great stuff. And we look forward to your webinars on VivaLearning.com and more podcasts in the future. Thank you very much. Thanks for having me. 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