Back to Back Class II Secrets (Sectional Matrix Troubleshooting) – PDP104

Jaz’ Introduction:
Hello, Protruserati. I’m Jaz Gulati and welcome back to Protrusive Dental Podcast. Today we’re talking about back to back Class II restorations, what I mean by back to back is adjacent. So we start off of Dental school trying to master the humble Class II and getting good at it and getting those nice contacts that are had to make that nice click sound when you floss through. But then when you start doing multiple and IE you’re doing quadrants, then you start to realize very quickly that actually, Class IIs are not very easy at all. Class IIs are actually extremely technique sensitive. I know we’ve spoken before with Maciek. He’s come on the podcast couple times. And so we’re gonna go one step further, and talk about some of the challenges that we face when we’re having adjacent Class IIs. And the inspiration for this episode was Dr. Ryan Cyriac. I hope I’m saying your name right, buddy. based in Tampa, Florida dentistry reached out on Instagram. I appreciate you, brother. Thanks so much for listening and watching. And you inspired this episode. So thanks so much. And I’ve got my buddy Chris O’Connor on today, who is going to do an absolutely fantastic job, I’m obviously I know you’re gonna love it, the amount of gems he’s gonna give you. So whether you’re starting out in Class IIs, or if you’re a seasoned practitioner, and you still haven’t quite mastered how to, which is the best way to do Class IIs when they’re back to back and you’re doing quadrants, then you will gain so much value from this episode. The Protrusive Dental Pearl for this episode is something that we actually discussed in the main interview, and it’s called the ‘Wedge Test.’ The wedge test is basically once you’ve done and you’re finished your cavity preparation, and you’ve got this saucer shaped design, and it is going to be conducive to a good restoration. Before you actually restore it now, you can do the wedge test. The wedge test is actually choosing the appropriate size wedge that you think will be best and actually placing it in position, it’s like a rehearsal, you’re rehearsing the wedge, and you’re just making sure that the wedge is doing what it’s supposed to do, ie it’s compressing the papilla, in the active part of the wedge is below the margin of the cavity. And to make sure that you are getting enough separation, ie there’s no point using a wedge, if it’s going to be really loose. And although it might be in the right position vertically, it’s just hanging loose. So you actually want a tight enough wedge. So you get some separation, that’s one of the objectives of get of using wedge as well as getting the right seal. So do you think you have enough separation? Is it stable? Is it not encroaching the space where the matrix is going to be? So if it’s encroaching ie it is too high up, it is too coronal. And if you put that wedge, it will be sort of crippling or occupying the space which the restorative material is supposed to occupy, then that’s no good. So here’s we actually need to modify the wedge ie using a scalpel or a handpiece or drill and just to get the shape of the wedge correct. So that is the wedge test as inspired by Chris O’Connor. And before we joined the main inteview, I just wanna say a big thank you to all the Protruserati, for voting Protrusie Dentsl Podcast as your favorite podcast in the genre of Treatment planning and occolusion, and also the runner up in general dentistry. I really appreciate that. This was all on CourseKarma. So CourseKarma is this awesome website where you can find reviews of all the different courses or live hands on courses and online courses. So if you haven’t already checked out CourseKarma, please do. So it’s a community of 1000s of dentists. And you guys voted as podcast as your favorite in those fields. So thank you so much for everyone who voted. I appreciate the love. I mean, last year, when I won the same category, I didn’t even know this existed. So this was like a big surprise. Now I did encourage you once to to vote. And I’m glad you did. I really appreciate this. It’s nice to be recognized in this way. So thank you so much. Now let’s join the main episode with Chris O’Connor and I’ll catch you in the outro.

Main Interview:
[Jaz] Chris O’Connor. Welcome to the Protrusive Dental Podcast, my friend. How are you?

[Chris]
I’m doing great, Jaz. And it’s a pleasure to be chatting to you on this wonderful platform.

[Jaz]
It is great to have you, my friend. Like I mentioned this same kind of intro when we did a little webinar, we did an on demand webinar with you, I and Alan. Berg Meister Alan Burgin on YouTube where we talk about finding central relation, that was real fun one, it’s got over 1000 views at the moment. And that was a real fun chat that we had actually. And that’s on YouTube available if you’re going to watch it. But the way that we met is I went to one of your lectures. I’m just saying, again, for those who haven’t had that, seen that video is that way we met is I saw you lecture. He had a lot more hair back then. So you lecture it was for the DPL. And it was, the title was, “Are you isolated?” And I literally came into lecture thinking this was a lecture about mental health and mindfulness and that kind of stuff. But it was actually about rubber dam. And it blew my mind that day, your rubber dam skills are insane. That was so many years ago. And just, you know, it just makes sense that now what you’ve become and what you’re doing with incidental, which we mentioned very soon as well. It’s just amazing. So it’s great to have you as part of a profession, advancing our restorative dentistry as a day to day basis. Chris, tell us about yourself for those who don’t know you.

[Chris]
Okay, yeah, great. So, Jaz, I’m, well, I’ve just graduated from Newcastle 2008. And I, you know, started off pretty normal, took some hospital jobs like yourself and was working in as NHS general dentist, and I think maybe a little bit like you, I really enjoyed teaching a lot. And, you know, I think, Why was I always felt and I think there’s a little bit with you as well, why you do this is the more you teach, the easier it is to learn. Because, you know that, show on, do one, teach one thing.

[Jaz]
Taxonomy you learn the most.

[Chris]
Absolutely. You know, I enjoy teaching but selfishly I mainly do it because it really helps me learn. So I was pretty keen on it. And I used to do a day a week at the dental hospital and I did a bit of bugs. And then I was working on some stuff and I did a few little like talks, you know how you start usually like making the most of you FD courses, people always seem to run that for a little bit. And then I got a big break with Northern Deanery at the time to do some practical courses. I think they were struggling to find people at the time. So it was really early on

[Jaz]
No, I’m sure it’s more than that, mate.

[Chris]
Yeah, it was early on, it was probably too soon. But it really I mean, I think three days, really lots of times for the FD. So I really had to really work on it and photograph my stuff. And this is kind of it’s not like it is now the photography is so good. I look at it now. It’s like, wow. But at the time, you know, I was working really hard. It was decent. And we were doing some really nice phantom head stuff with the FDs. And I’ve done that the last 10 years really, ever since then. So I was doing quite a bit of teaching. And then I went back, I sort of was getting a bit sick of NHS dentistry. And I decided to go back to the Newcastle University to teach as a faculty and I were there the last sort of seven years really just left recently, so I was doing my PhD running clinical trials, I did that with the 3M, I taught in the master’s program, and we’re in a way of kind of doing that. And that’s been great. And then, you know, a couple of years ago, so I’m on, I think I’m on my third career. So that was my second career as a clinical academic. And that was good for a while. And then a few things happen, you know, COVID here, the job changed somewhat. I had a bit of a reevaluation. And so now my third career, which is sort of incidental, which is, you know, I’d had a platform called incidental blog, when I first graduated, which kind of got me into the Lightroom, which was like a, bit like a guess, and very rubbish Instagram page would be now, very rubbish. But it was good at the time. It was okay at the time. And so I had this incidental training, which was what I called all my courses for the FDs and lifelong learning. And I, we set up incidental limited, which was selling products. So one of the products, we used to use a lot on my courses with the TOR VM ones, and they were getting really difficult to buy in the UK. So I was like, well, let’s try and sort that out. Because it was getting really annoying. There’s just so many fakes out there. So we set the company up

[Jaz]
The reason I just want to given you incidental plug because there are so many counterfeits out there. And I really enjoy using Tor VM matrices, a funny story, actually my nurse when I’m teaching her the different matrices names, because you know, as we know, there’s no one matrix for every scenario. So we got to keep a couple of different types of matrices. I know that you guys talk a lot of them. But my nurse for some reason she just couldn’t get on with a term TOR VM. And I said, Can you give me the TOR VM 30? Can you give me the TOR VM 50? So now it’s called the Russian one. And she’s so much happier with that, and I’m happy with that. It just sounds a bit weird from the patient. Can you give me the Russian one? But anyway, that’s what we do now. But yeah, you guys sell the genuine stuff, because there are a lot of counterfeits, and a lot of the UK Dentists have been stung by that as I’ve seen on Instagram.

[Chris]
Yeah, and there wasn’t at the time there wasn’t a UK distributor and I think it’s difficult I think some pressures from the market that, I don’t know why they weren’t picked up to be honest with you. You know, TOR, you know, matrices for a lot of people as well you know, different ones and but they they’re fantastic product, amazing product, they’re really innovative. And certainly we got them on the market and that literally was pretty much the goal, was basically just so I could buy them without being a pain. And then I did it with a couple of mates. Like all good ideas that came up in the pub, and we were like, let’s give it a go. And, yeah, it’s sort of this, where do we start training a couple of years ago, and we started trading only 18 months maybe ago. And then, you know, kind of got bigger, quite quick. I got some teaching a long time. So I had some help from people I knew to get the word out. And it’s a great product. So it took off, and suddenly needed a bit more time. So I finished WT on term. And I been doing it people time since July. And then I’m just going back to clinic, the end of this month, actually, because I’ve been really missing it. And you know how it is when you start a business you just got to fix the problems and get it sorted and get going. And then now it’s doing okay, and you got some stuff involved and get them going, then I’m hoping I can balance the clinic on that as well. So that’s been cool. And we’ve spun off training courses with, you know, Alan Burgin and my really good friend, Ollie Bailey, who’s a fantastic academic and got really similar interests. And yes, I don’t know, that’s probably more than anything to tell that, but it’s going

[Jaz]
Great introduction, because we like to know everyone’s journey. So your journey is very much from teaching quite quite early on about how to do you know, direct restoratives and some of the papers that you’ve you know, you’ve been very humbly haven’t mentioned some of the papers. These papers guys are so practical, so pragmatic, so useful, like I discovered quite late on about papilla management and all these things, but I see some of your papers from years ago, talking about that kind of stuff. And like, hang on a minute, why didn’t I read this paper before? So some of these you very kindly shared on the Protrusive Dental Community Facebook group, so if you don’t mind, I can share them under this podcast, a blog post with everyone as well?

[Chris]
Yeah, I mean, that’d be great. My interests are, you know, well, direct restorations, bonding, adhesive dentistry, I guess, a lot of you know, I mean, really, Jaz, when we real, was when I was teaching off your Resin Bonded Bridge papers, you know, and they, and they were similar, you know, they were great, really grounded, really practical, really, you know, really enjoy, so yeah. And, yeah, they’re about that. And then more later looking, I suppose I’ve been looking full mouth stuff, I suppose. That’s a kind of a classic journey, getting a single tooth stuff. And then you

[Jaz]
We like to talk about these things on our Facebook, don’t we? Along with Alan Burgin, and Richard Mackinder, and all these great people. But today’s episode is very much about a challenge when it comes to a Class IIs because we’ve talked a little bit about Class IIs, we had Maciek, on who we both admire very much. But one thing we haven’t talked about specifically, is when we’re doing that scenario of Back to Back Class IIs, ie adjacent Class IIs, like a distal of the second premolar, the mesial, or MOD of the first molar, and maybe the mesial of the second molar, that kind of back to back Class IIs. And this was inspired by Dr. Ryan Cyriac. Hope I’m saying your name right, buddy from Tampa, Florida, who said Hey, Jaz, Can you cover this topic? I’m like Yes, I know exactly the guy I want to cover this topic and here you are. So let’s talk about the challenges. So if I share some of my struggles with you, Chris, because it’s something I’m still, I don’t think I’ve mastered at all. And I know you have to break it down for me. Because when I have that situation, when I’m doing a quadrant and isolation, I have no problems with I’m happy to isolate in any in all scenarios, I’ve worked really hard on that over the years. So isolation for me is not a struggle. The struggle is I want to be quick, and I want to be efficient, I want to be more than quick, I want to be efficient. And the ideal scenario is that when I do my etch out, I would like to etch all the enamel everywhere. And I don’t really etch the dentin so much, we can talk about another time, but I want to be able to then bond and then place my composite as an efficient way to do an increment in the second premolar, do an increment in the first molar, do an increment. And that for me is I can be so much quicker. But the reason I have shied away from from doing that, and really I nowadays I probably manage one tooth at a time is I feel as though I get a better tighter contact because I burned my fingers in the past where I’ve got two matrices side by side, maybe two TOR VMs or a TOR VM and a different type of matrix up against each other. And I feel as though that once I remove the matrices there wasn’t as tight of a contact area as I wanted. So please just talk about some challenges that we faced with back to back. So any advice you have on that and how do you do it now?

[Chris]
Yeah, it’s a classic dentistry isn’t it? It’s sort of speed and control and it’s yours. You want the control and sometimes you have to sacrifice and speed for that. And I agree, I think doing lots together gets difficult and can get messy and is less predictable. So you sort of, you go one way and usually you come back so. So let’s try and break it down and make it tangible, Jaz. We will start like you sort of went Yeah, we’re gonna be using sectionals and stuff like that. So maybe just a tiny bit on that idea. So really quickly, you get like, a single Class II, and you put a tofflemire or any active band on the tightens, because you can get curved tofflemire bands, but they, when they tighten, they tend to go flat, and you get a contact that’s really high up the tooth, and usually too high and you polish it off, and you don’t get a nice contact area where you want to contact area, there’s low down, and then the contact profile will come up, touch and curve back on itself. And that’s much easier to clean, much easier to floss. And it’s much less likely to get fractures, which are the second most common cause of composite failure is fracture. If it’s like a thin, flat contact point, it’s unsupported at the top, and they tend to break. So that’s the goal. And that’s maybe why it’s difficult to do the best contact points with active bands, right? So that’s how we do them. And then let’s go into that. And so an alternative to using an active band is using a passive band, like a sectional band used to have a really nice curve to them. And then classically, you put you put that band in, and you’re going to play some wedge, and just really briefly, what do we put the wedge in for? Seal cervically but also to create separation classically. And let’s say a wooden wedge, which is the only one we have good research on that can separate the teeth by about 90 micron, and then it drops to about 60 micron. Okay? So that’s the separation you can get probably

[Jaz]
What do you mean by drops to at? Why does it drop? What do you need?

[Chris]
Yeah, well, there’s very little research on like, distance of separation. And of course, it will change between patient, you should probably why it’s not amazingly well researched. And the guy did this, this study is from Heli, which is down in 1986, as a pilot study, and it’s pretty much the only paper on this, but what they said in the paper was if you put a wooden wedge in, they all separate about by 90 microns initially, as you as you place it, and then it will drop back down to 60 microns.

[Jaz]
So like a rebound?

[Chris]
Yeah, some bound to happen, but there’s also been in the paper about how you can swell with the fluid that might kind of aid it. It’s really interesting, cuz that’s literally it. That’s all we’ve got about distance, the other stuff is all about tightness. So that’s from the guys from the Redbone University, mainly, you know, I can make OBLEMS group and bass lumens, and they look at it, but they measure like how tight the contacts are afterwards. So it’s not on distance. Now. I like the distance stuff, because we pick the bands by thickness, right? So that’s really helpful. And if I hadn’t left clinical academia, I was I would be definitely wanting to look at that. I think it’d be cool. Maybe I’ll do it anyway. I’ll figure it out. So anyway, but the reason we use the wedge was classically to create the separation. So you put your male band in, tofflemire maybe flat, you put your wedge in and you creating this 60 microns. So you need a band, traditionally, that’s thinner than, you need to separate by at least the thickness of the band, so that when you take the band out, you’ve got a contact point, okay? And I think that’s sometimes forgotten a little bit. You know, I remember when I graduated, just tightening the band up and going, Oh, it’s seal cervically. I don’t need a wedge. And then you’re like, afterwards, I need to wedge , actually.

[Jaz]
Yeah, definitely been there.

[Chris]
You need to keep the separation. And we just, it just sectional matrices came out. And it was all like, oh, you know. But we forget, like, just the fundamentals what you’re trying to do, you want something that’s stable to absolutely doesn’t move, seals cervically, and creates the separation? And critically is usable, it has to be doable for the average human.

[Jaz]
What do you just, before we continue a Chris, man, I know, you can talk day and night about this topic, but just talks to us about the value of pre wedging. I’m a big fan of pre wedging to compress your papilla to get some initial separation to reduce the chance of iatrogenic damage, or quite losing the wedge guards as well, that kind of stuff. Where do you stand on pre wedging?

[Chris]
Yeah, I mean, all those things that you’ve you said, I think is an it’s pretty well established. I actually, funnily I do pre-wedge, I like it. But there’s always a period in there, I think you pre wedge like a pre wedger. And you do, then you only have to take the wedge out at some point to finish the margin. How much space? It’s all like, I’m pre separating, and I’m no, no, no, but yeah, let’s do it. Let’s go. But say like those wedge guards, for instance, though they’re in a passive wedge. So they don’t create any separation because they’re V shaped, or usually anyway, most of the bands are. So you put that in, and that’s not creating any separation. It’s lovely for a guard. But then once you break the contract, but the thing comes loose anyway, doesn’t it and you start going, you know, so then you take it out, and you put your wooden one in and so it’s helpful, but I think still fundamentally, you need to be wedging. Well when you do the band and usually we checking at that point anyway. So I do it, but it doesn’t change the critical point, which is when you finish a cavity prep, you need to do a wedge test, you need to find a wedge that’s going to achieve the goals that you want so that it fits below the cavity margin so it seals and so that it doesn’t deform the matrices by raising too high or stopping the contact profile. And, or it might need trimming or you might need a low profile wedge, whatever, but you need to find one that solves the job. And that doesn’t go away whether you pre wedge or not.

[Jaz]
This wedge test is Why, it’s one of the many reasons why Class IIs are not easy. They are so fiddly, they are so technique sensitive. And we sometimes in dentistry, the mistake we made as general dentists we think that oh, classy was one of the first thing we were taught at dental school, therefore it’s an easy thing. But to get proper isolation, proper matrix election, proper wedge selection, doing a wedge test. This is why it takes time to do good direct restorative dentistry. And this is why we should charge appropriately. And this is why we can’t do fillings in 20 minutes, whereas some colleagues can but then there’s a difference, you know, you’re looking for that difference in quality difference in what you’re trying to do. So as long as you respect the fact that Class II is really and properly, they’re not an easy thing to do.

[Chris]
Yeah, and, you know, let’s just like that papilla paper we did, we sort of break it down about what to do if you fail the wedge test, right. So if you, if the wedge doesn’t sit below, it just deforms the band doing, you’re going to create, and we become sort of obsessed with matrix distortion. You know, and this is for lots of things. But the first thing, the rings and everything make a distortion, and we can go into that later but or not depends on how much value but for like the wedges, the first bit if the wedges deforming the matrix, before you even started selecting your matrix or selecting your ring, you’ve got no chance. So it’s key. And if it’s not, you either need to take the gun down, or you need to do the cavity in two steps. So you might do a first hip where you just build it up without creating separation. And then you do the second stage. And there are two strategies, which are will both work. And there’s a time for both, you know, so in and this is important for the back to back, because the back to back adjust this. But more difficult. So we need to stabilize, which is more difficult, because we’ve got two bands and things are moving, we need to do the wedge test. But that’s kind of difficult as well, because they’re at different heights, divinely. So all these things well, we’re dancing around the topic of back to back, they are intrinsic to, it’s just maybe one of those situations, which kind of focuses the mind because when it goes wrong, it goes wrong more horribly.

[Jaz]
Well said. So really, in those situations, when we got back to back Class IIs, we still have the fundamentals of everything that we do in our, you know, single Class IIs, but it just becomes a bit more difficult because like you said, there might be a different where they finished in terms of cavity margin, the wedge test may be more difficult to pass in that case. So give us some, I mean, so one of the challenges I’ve had in the past, so we can go through it. And one by one is, I mean timing, when, what do you do at the moment, Chris? In terms of Do you like to then like one of the ways I was always taught to classes always do the the wall first convert it into a class one and then and then go from there? So A) Is that how you tend to do and then B) part of that question is, do you like to do the efficient way and do them all at one time and then cure? Or are you still very much doing what I do to get that control, but it slows you down a bit, it’s do one at a time. Because just like you touched on earlier, you need to create the space, or you take the separation of the thickness of the matrix when you got two matrices next to each other, you obviously need to create more separation in a way. Tell us.

[Chris]
I mean, generally, it’s one at a time for me. You can either do the, you can do the walls, but you still do them one at a time and do the rest, you know, or you can do the wall and finish it and move and do you know, and there’s sort of a nice thing in doing the increments. B, you’re generally going to have to sort of re-sand blast because it will get probably get contaminated at some point, you know, so it’s kind of sometimes it’s slightly more efficient, but often it’s a false economy and just complicating it.

[Jaz]
Just to check, Chris because you mentioned that point about doing one and then doing the other but what I think you mean is do one and then remove that matrix. Henceforth, you’re removing the thickness of that matrix, and then re wedge test and then you do the second one, right?

[Chris]
Yeah, let’s just walk it through because we’re gonna there’s so. So let’s just, let’s imagine we’ve got a five and a six. The fives got a DO, the six has gone on MO, okay? So we finished the cavity preps and we want lovely smooth ones. We want a nice sort of saucer shape and low stress. So let’s get that done. Now we’re gonna matrix them both, okay? And there’s a couple of, so one of the things you might want to you know, we were sold these kids in 2008 particularly, but the sectional band matrix kits have been out since the 1950s. But you always sold you know, it’s a bean shaped band, you’ve got the ring and you’re like, I’ve got to use all these things on the, I’ve got it there. I’ve got to use them. If you try and do one at a time and you place a sectional band and place the ring of course what happens it just encroaches or buccal out into the other cavity, you know, and I’ve seen that done, you know, Facebook Instagram people pose again, you can see that just sort of use the kit kind of as they would normally and it’s disastrous because there’s nothing to separate against, you know. So you just place one matrix. So let’s say we’re doing that six and the five and we placed it on the six

[Jaz]
And I just want to say, Chris, it’s first molar and second premolar because we do have people from the US and when they get five to six, they get a bit confused. So we’re gonna use second premolar because it was actually American. It was Ryan from Tampa, Florida, who asked the question so in a tribute to you, Ryan, we’re going to use a secondary premolar and first molar. So yes, you put the the matrix in the first molar, but then that then will then encroach the space of the second premolar

[Chris]
Yeah, and it’ll tick in naturally, or it’ll be hard to secure. Remember, one of the goals of the matrix wedge is separate a complex is that it’s stable enough to pack it, you really got to pack composite, otherwise, you’re gonna get voids and all those kinds of things. So it’s going to be difficult to get stable. And if you do, it tends to encroach into the other cavity. So early days maybe, Oh I can fix this, I’ll put a load of PTFE tape in the premolar cavity and tried to build out. And I’ve tried that and what tends to happen is you still get it wrong, you still go too much over over one way, and you end up with one that’s too big, and then you get really difficult contact by separately. Another option for you is if you try and do them both at the same time, so you put your two sectional bands in, and then you try and separate them together. And the difficulty you’ve got then is they’re both loose, they’re both unstable. And if you then put a separating ring on or something like that, they buccal in together, they haven’t got enough support. Or if you try and just do it with a wedge, you can’t create enough separation, because you’re trying to create like 100 micron a separation now, because you’ve got two 50 micron bands, so that doesn’t work to either. So the best way to do it is place you’re band in the molar, place your band carefully in the premolar and share the space out, okay? So you share the space out by having both bands in position at the same time. An interesting one, then is whether you place a wedge or not. So you can but because they’re both moving, it can be quite hard to get the wedge in, okay? It can be quite hard to satisfy the wedge tests on both cavities. And sometimes it will make things sort of move or shift and things. So if I can get a really good seal, I will happily not wedge at this point. So don’t need the separation. And I’ll actually secure the two matrices with some liquidam, which I use a lot, a lot of my Class IIs, I’ll secure everything with the liquidam. So you put that in and cure it and there’s one you know, you can tell, can you if you’ve got the seal cervically and it’s gonna be secure, then you’re all good to go. So then you can fill the molar.

[Chris]
So there’s no ring here. So you’ve just got the two matrices in place to make sure that the space is not encroach. You’ve got your liquidam in the embrasure space just to keep it stable, for stability. And there’s no ring here because you don’t need the separation because you haven’t got anything to separate against?

[Chris]
Yeah, you don’t need it. And when you place a ring at this point, you will lose those beautiful curves. And they will almost always distort because if you think, these rings, and you know, there’s that I will talk about a lot. They’re like springs going in. And this is I think this is, I think we’re in a new phase of matricing. I really do. I think we have the first phase like 1950s, we have the second phase 2008 when Trident came and boof and it was these rings, these niti rings are really strong and, and they and then soft bands, because we were like we need to do some and then and then what you realize is these rings and the soft bands just really flat or concave profiles. Because the ring is so pushing in and sweeping everything off. So I think, so this point particular is a mistake to do that because you’ve got nothing even steady two matrices against the two matrices next to each other. Another thing, Jaz Lusia is the space this, you know the space between those two cavities, particularly with premolars, it can be quite a big I call this a bridging gap. So it’s the space between the cavity and the next tooth, or how far you want to get across

[Jaz]
The base, we’re talking about the base, the very base of cervical gingival base of the cavity, right?

[Chris]
Yeah, so like, for instance, pre molars are more curvy, the molars. Right? So and this is my model, you know, as researcher, you know, using matrix bands for every system and every, And one of the problems like classic problem is a premolar is more curved than molar. But all the sectional bands seem to be like made for molar. So they only have that profile for them, like pretty much like that’s kind of how they were. And so I’ve seen this on Instagram, particularly like someone’s put in a matrix on the six and the five, but they’re not touching together because the bands aren’t curved enough. And that’s really difficult. And so they might try and solve that problem by putting a ring on. And the ring will tip them in together, which might work, but it will just deform them like crazy, too. So it’s not, that’s not the solution. And what was really cool in matricing was David Klein, the bioclear guys started to release matrices of various curve. And you know, Maciek you had on, you know, he, I think he did a wicked job of picking that up looking at bridging gaps and going look, we need to actually we need different curves for different situation and I 100%, that’s it. And so you need them to touch. And what’s great now is starting to get more options for more curve bands. Because, you know, let’s say that band, you want them to actually touch and share the space, and you might want a more curvy one on the premolar and a slightly less curvy on in the molar. Or you might want two very curved ones if they’re got a big bridging gap…

[Jaz]
If it’s very concavity.

[Chris]
Yeah, one of the cool things with working with TOR VM was they were distributing for them, I was like, Would you please, it would make my life if we had some more curvy bands. So we I actually designed them prototype them and we developed them these double amazing. And it was cool, because before they were only available in mailer, and malas got some good things about it, but it’s quite thick, it’s usually 70 to 75 micron, which is got some issues. And also it’s quite fiddly to place. So we’ve now got some curved bands. So typically this situation, I might put a regular TOR VM on the six and a double curve on the five maybe, tack them and do six. Yeah, once you finish the six, cure and everything, you then have a lovely opportunity. And you’re going to take both of those matrix bands out. And you have a lovely opportunity just to check the contact profile. And check, there’s no overhang and finish that. And that’s why the first cavity that you do with usually I’ll do the more difficult one. So get that one done. I’ve got the six, the molars then done. And now I’m going to go to the pre molar. And that’s very much like how you would do a classic, Class II now you’ve got the wall of the six to do. So you’re going to go ahead and put your band in, it should be the same one you did. But occasionally, you know, it’s worth checking, you’re going to, so before you put the band in, you’ll do your wedge check, make sure you’ve got a wedge that’s going to sit below then place the band, place your wedge. And then at that point, you could place a separating ring or not. So separating ring, mainly people like to use them. We know from the lumen studies and all of these that it creates a huge amount of separation, possibly too much you don’t see any damage. And you’ll get a really tight contact point, definitely. What I would say to you is when you put a really strong ring on, you quite often get defamation too. But that band. And this is classic, right? You put the ring on and it just goes off square, or it buccals or…

[Jaz]
Crumples. It just crumples.

[Chris]
Alright, I remember your Maciek, the episode you did with him about how it can gap at the bottom of cervically. And he talked about pulling it up. But I, for me, the reason that happens mainly actually is because of the ring, the ring puts it under tension the band, and it just, it tends to opens. And if you want to know more about that, have a look at my colleague, Ollie Bailey, who would do with, he wrote a really lovely article on “Matrices: Distorted Truth” about about these rings, about the defamations. And start looking at it…

[Jaz]
I love that title.

[Chris]
And yeah, this was based on some work we’ve done together and some lectures we gave him and he wrote it up. And it’s beautifully done. And we just, we’re not saying don’t use a separating ring, because you obviously get really tight contacts. But there’s a massive issues with it too, that it creates these concavities. They look and you can’t see it when you’re finished your filling but like we were doing a lot of tests and taking them out models, and you can see these concave, you know, the city is looking at this, these concave surfaces, which are almost impossible to clean, because they drop in. That makes sense. And all these…

[Jaz]
It tends to make, Yeah, exactly where you don’t want that concave surface at the junction of the interface of the restoration of the tooth, you tend to get a little, just little bit higher up in that you get these a concavities. And that makes perfect sense. Really, what you’re saying is that just because we have the ring available, doesn’t mean we always need to use the ring and sounds actually, a lot of times you can get away without using the ring. As long as you have a decent stable wedge, which you think is achieving enough separation now that you’ve done the first molar and you can really feel that okay, we’re getting some good separation here on the..

[Chris]
So I have one band then and I will either pick a 35 micron band, which is pretty thin TOR VM hardest steel generally, or I will pick a maybe got some really nice new titanium ones which are 30 micron even thinner. Why they’re nice because they have this memory quality. So they’re quite cool and playing with them at the moment. But anyway, you put that in, you’ve only got to get separation of 35 microns. So why don’t we need a ring, you know, we know we can get that with a wooden wedge as long as it’s well secured. And if we put that in, put the wooden wedge in, the only thing that’s missing is that it’s unstable because the ring helps stabilize it too. So what I will tend to do is get my trusty liquidam out getting some around the tooth, around the band, cure it, and that makes it absolutely solid so it doesn’t move. And then I’ll fill it to dismantle and I’ve got a lovely contact and it’s not too tight, I think there’s a problem with too tight contact points as well. It’s too tight from what we have, you know, in turning what you have, naturally, then what happens is the tooth just drift back anyway. And you know, there’s some studies looking at contact tightness and it starts off tight just goes, you know, back anyway, what we’re trying to do is recreate nature not make something art, you know, I think I definitely had quite a long period where I was obsessed with making contact points so tight that they were almost impossible to clean up, I have nailed this is not the case, it just needs to be, you know, tight so that we don’t get food impaction and natural, you know.

[Jaz]
In the natural course of all restorative dentist who enjoy what we do. And we all go through this phase of learning and experimenting, I think we all can put our hands up and say we’re guilty of making overly tight contacts, because we think we’re doing a great job. And interestingly, I saw on Facebook once there’s a guy called Dr. Vasil Crimpi, I am so sorry, if I’m mispronouncing your name, buddy. I want to take a stab and say he’s from Romania. But I might be wrong. But I saw it on Tomorrow Tooth group where he posted a case where he admitted that okay, I actually I made these contacts too tight. And then the one year follow up the premolar, which was in the middle of all this tightness started to intrude. And then he eased the contacts. And it started to extrude again, so that was really cool to see.

[Chris]
Yeah, I mean, let’s just name check, Tomorrow tooth unless and Pasquali Venuti. You know, those guys, because this idea of tacking with liquidam, you know, definitely, you know, picked up from them, I think, and then I ran with it somewhat. But you know, the, this idea of stabilizing without the ring has been massive for me. And that’s something we teach and we look at, and you know, just place the rings, but actually, the more I’m doing it, and the more that we have available different curves of bands, the more one of the main reasons you need to bring to tip the band against the tooth, if you think about it. If you don’t have a contact, when you place the band passively, you have to tip it out to get the contact, and the ring will do that for you. But when it does that it flattens it too. And so you’re back in that tofflemire situation where you have a flat contact, there’s too high up. And so I’m pretty excited about the developments we’ve managed to do with TOR to make these different curves. And also the bioclear was a game changer with that. But the problem with their rings is you can get the curve, but you have to have a ring, because there’s 70-75 microns thick, and you just can’t get enough separation with the wedge. So it’s really exciting to have bigger curves available in thinner in metal for me for a technique that I like, and the one that I’ve been working on. But you know, annoying thing about matrices as you know, is there isn’t like oh, and then it all works. And that’s definitely there’s a lot of troubleshooting and problem solving. Just one thing to just talk about when you do the liquidam on the second if you do a back to back, if you’re not careful, the liquidam could stick to the composite that you’ve just finished. So you do the molar, you finish that, you do the premolar and you tack it again. And they do together and on the course sometimes I forget to tell y’all glue them together. So you need to put some glitter in and cure after it to get the oxygen hidden layer off or have finished it and polished it first. Or you use a different technique or sometimes on the course because we don’t have the glitter in everywhere. It’s messy. You can wrap some PTFE tape around the teeth just to be absolutely sure. But that’s..

[Jaz]
Great point.

[Chris]
It happens more on the models when we’re training when it happens in real life

[Jaz]
While we’re just on that point with liquidam just to make it, give some dentists some more ideas. So one of the things about liquidam when we’re using it to in that way to get some more stability of your second Matrix let’s say, the other benefit is that a action geek can give you a buccal and palatal seal as well so that there’s less mess to clean up at the end that’s all it means really. Because if it’s not the end I always used to be work really hard. I used to get stressed myself out on really making sure I had this coverage of the matrix on to the buccal wall and the palatal wall and put all this liquidam when really I sometimes think okay, so what if I get a lot of excess it’s so easy to get number 12 plate or soft flex and just clean it away. So I’m a little bit less stressed as long as my cervical seal is on point.

[Chris]
Yeah, I call on that definitely. So when you, one of the difficult situations you’ve got and why we do what we did. Basically I’ve made all these typodont scenarios with all slightly difficult different situations and we do it just totally problem solving. It was basically that I felt like the way to learn this is by learning to troubleshoot because there’s no recipe. So this is just the base of the course, we just made all these scenarios and, like gave some idea you know, there’s all the kit valuable all the bands. And you know what, let’s try this, try that and figure it out yourself because that’s how it’s like in real life. So that was the whole idea. But one of the ones we do is a white box where you’ve lost that buccal and lingual support. Yes, I’m and that’s definitely one I’m, if you try to wrap the band buccal and lingual, then what happens is you flatten the band, and you lose the contact profile, because you’re putting it on detention and torture. And that’s what we do with the rings. And it’s even worse when you use a ring and you’ve lost buccal and lingual because it’s got nowhere to go and it has to buccal in. And so you know, you see people do it and they try and like build the buccal, build the lingual and then place the sectional band and then place the ring, you know, and it becomes really fussy to do it that way. Take a very long time. And so what I would suggest is just place the band and get the band, get the contact profile. That’s the bit you can’t finish and polish get that right and leave it open almost buccal or lingual, tack it, finish the restoration and then if you have to polish back the buccal or like you say it’s no problem but don’t, the bit you cannot, you cannot do anything about is the contact profile. That’s what I mentioned above. And just a tiny bit on that, a new trip that I’ve been and you know, most of stuff, Jaz that I do, I’ve nicked from somebody else, pretty much, same as you, you know you , you take, you making your own but you nicking everything…

[Jaz]
I’m the first admit that you know that.

[Chris]
But a nice thing I worked out was these titanium bands, we they literally only just come to market. This this center is what you can do with them is like I say like I call it activating them. So you rub the band in there. And they go from being like a solid form to be like a spring. So they’ve like opened up and stuff. So you can get one of these and you run it with a probe and it almost like killed upon itself. Can you imagine that. And then what you can do is open it up on these wideClass IIs open it up and let it kind of naturally wrap around the tooth like a little ice cream. And it’s a really cool technique because you’ve got the profile, but you also help it come around buccal and lingual but it does it in a way that is not deforming the band. And if anyone if that makes a bit hard to envisage, we have an Instagram and I’ve got a little, I do a little short videos. And that’s one of them on how to isolate..

[Jaz]
Please tell us your Instagram handle. Because it’s a very educational page. Lots of great stories and videos and great videos on phantom heads, on patients showing these techniques. So just remind us of your Instagram handle.

[Chris]
Yeah, so it’s incidental limited. And you know, that’s a webshop @InciDentalLtd. And we yeah, we do little TOR things to rubber dam, matricing like that, we do these, like, you know, to do these reels where we put it, like really short. Shoot it and clip out. And people can have a little bit. A lot of these techniques, once you’ve seen them once you’re like, you know, that’s it, and that’s the great thing now with social media, you know, you can pick up these tips so quick. And then give it a go. And I’m pretty sure you’ll get some really nice results. And

[Jaz]
I’ve seen these videos and they’re so let’s say that tangible there, you can pick up these tips and apply them on Monday morning. So I really appreciate you sharing that. I will share the instagram name in the blog post as well. And on the YouTube when it comes on. You covered the main points I wanted to cover for Ryan and you actually really helped me as well to remember some of these points about the matricing and the thicknesses and the wedge test. So that’s been absolutely fantastic, Chris. Any final points about, any tips that you want to pass on to dentists when they’re approaching these challenges with back to back Class IIs? Before I then also want to find out about your courses in 2022 and beyond?

[Chris]
Yeah, so one thing I didn’t do, which I was going to which one to do first?

[Jaz]
Yes please, any guidelines? Yeah.

[Chris]
Yeah. So just to sort of thoughts and schools of thought, for me is just do the most difficult one first, because you have such a good opportunity when you’ve taken both bands out to finish it and check it. And you don’t get that, you can’t use and get to the proximal surface to do anything. So that’s amazing. The other, So which one’s most difficult? And which are the most difficult usually, I will say the one that’s the most claustrophobic. So a big molar Class II is usually a lot easier to fill actually than a really small type premolar. And especially if you’re someone who religiously doesn’t believe in bulk fills, because you’re gonna have to do them in tiny little increments and things and it’s really difficult I would venture possibly impossible. And so the claustrophobic ones I would do first because then more difficult. The other thing to look at is the cervical height of the cavity margin. Again, the lower down it is, the harder it is to do the wedge test and if on this first cavity you don’t necessarily have to get below it as long as it’s sealing. So it’s usually I would do with a deeper one, and then leave them the shallower one to be able to do the wedging when you need the separation. So, yeah, probably a hierarchy.

[Jaz]
That is a great. I’m glad you mentioned about the claustrophobic because sometimes when you say, do the difficult one first you think, Oh the bigger one. But no, it’s actually the other way around.

[Chris]
I mean, it’s almost, I mean, we got a whole bit we do on claustrophobic for everyone’s and you, we actually teach two different technique for claustrophobia. Because, you know, you just got to be pragmatic, you can’t, you know, one of the things, I suppose being a researcher, being a teacher, I suppose, we spend a lot of time devising practicals, but also doing them and then taking the teeth out and looking at them. And you learn a lot by doing, you can do a lot by playing the typodont, like, and I’ve never spent more time with typodont this year, I tell you that, developing products, looking at products, having a look, and you know, you’re taking them out. And it’s just boring. It’s just voidable. You know and, you know, there’s two, there’s the argument on shrinkage, of course, there is, and we want to keep volumes, but there’s also like, a practical thing of having voids everywhere, like, that’s crack propagation. You know, there’s usually, there’s roots in often, you know, and so there’s a whole other argument there. And I suppose that’s why those two camps, you know, and I’m not in, I would hope I try to straddle it a little bit, but that, it’s a bit like that adhesive versus conventional dentistry argument. It’s like the bulk fill versus small increments, you can see what they’re both trying to get to. And I just think you have to be pragmatic, and claustrophobic cavities, I think it’s borderline impossible to do them in tiny increments, in my house, for these bands. Definitely.

[Jaz]
I’m with you on that, I also tend to bulk filled use the bioclear principles, when it comes to claustrophobic ones, I just feel like to get a better finish and less voids,

[Chris]
Things like for me, like a little drop of flow before each increment, you know? And, you know, it’s, you know, if you, someone described this to me, as if you looked at how they do plastics in any other industry, it would be injection molded, right? Because you don’t want, you need, you want to create a nice, perfect servers, you know? And definitely, if you take them out and look at these these pots and wards, which you can’t see in them out, you know, that way, you do get a really nice finish on it. Except there’s other downsides, but some of the really nice bulk now or bulk of flows are available. I think, you know, it’s not perfect, but I think it’s pragmatic. And it works. You know.

[Jaz]
Amazing, Chris, you’ve answered all my questions and given so much value to Protruserati. Tell us about some of these courses that you and the Bergmeister are running, I’ve seen some really great reviews online, tell us about the locations and how to become.

[Chris]
Yeah, so InciDental Limited. We’re a product company. And we’re getting asked a lot to do sponsor and things and that was great. But I’m a bit of a small one man band, it’s pretty difficult to take all this stuff. And my background was teaching. So I thought, well, let’s try and do and Alan’s phenomenal Dentist really talented. So he’s one of the speakers, myself, Uri. And Ollie, who’s a fantastic speaker, and clinical academic, too. So there’s three of us. So it’s, it’s pretty unique, like those three, when we share it out. And we’re all coming round, we have printed out. And we did it as a three day, three day program. Because we thought, you know, an a day you always spend so long doing the bonding, you can have to do it, you know, you have to go through the bonding, or you have to go through a cavity prep design, wherever. But actually, what we want to do is have loads of time for the really difficult stuff. You know, you need to get everyone up to a level so we do this three days, or we do two days posterior and one day anterior pretty much, so we kind of cover everything, it’s got massive focus on matricing and to go into massive focus on problem solving. I spend a lot of time and investment because they are developing all these typodont scenarios. So there’s we have soft tissue models for you to to manage both in one…papilla. Also do DME bands and do like various ones and do it in two stage in different ways. And there’s big rubber dam component so it’s all like basically, it’s just all the stuff you get on courses but wrapped up in problem solving.

[Jaz]
Chris, I wish you had this like so many more years ago when I was a new grad and I was going through all the struggles I had to learn in the deep dark world, all the bleeding and all the errors I made all the mistakes I made I wish I had something like yours because look, I did go on posterior composite courses but it was just a one day and it was mostly about the upper first molar has this many cusps here and this many cusps here, no course ever went on was so deeply passionate about matricing like you are and wedging and that’s the beauty of it. That’s the real challenge it’s not the anatomy.

[Chris]
Yeah and it’s absolutely, I’m okay, every is new as we’re recording this after new year and every year using resolution is that barrier on occlusal anatomy and I’m pretty sure it won’t have happened this year either. You know, I’m okay, I’m all right but I would I you know, I would say my contact profiles are good and that’s why I had Alan Burgin because he’s amazing at that stuff. Yeah, mine looks nice, pretty military, but that’s still, right. And Ollie’s amazing anterior work. Fantastic. So between the three of us, we’re really covered bases, well, but it’s that, you know, comes, in courses so many. And that’s it, it’s awesome. And what I wanted to do was, I’ve been on loads, and it was always the same Class II, like a perfect Class II, or whatever. And it just didn’t come back and then go into the real world, I suppose on making your work. So that’s what we try to fill in those gaps of all the hard scenarios that we do. And, you know, I’m really into and then the feedbacks has been good. And people seem to have enjoyed that. And it would complement a really aesthetic course. Definitely. I mean, we do a bit of that, but it’s definitely not that, there’s all the anterior matrixing as well, of course, and all those things, and it just, it’s a bit of a showcase as well to try we have all the products we sell, but we also have, you know, we’ll have all the other ones we’re not, you know, it’s not particularly, you know, we use the bioclear Diamond wedges, I can’t get a distribution rate for them, I don’t think but you know, and we have products I can distribute, you know, it’s quite hard sometimes…

[Jaz]
That has to be admired. It’s really good that you know, as a company that deals with products, but you still for the sake of education you have to and it’s great that you do this, show other brands are available and how to use them in the best way so massive kudos to you. Please send me the website links. So I can put that in a blog post so people who are, who can check out the date anyone coming up anytime soon?

[Chris]
So we are limiting ourselves to we’re doing three courses this year, we sold out for last year. We’re doing bus sold out, but we’ve got Newcastle if people, please come. It’s we do really well in Newcastle, yellow people, but there’s so much easier for me to run them there. So it’s really convenient…

[Jaz]
Listen, two things that Newcastle, you get three Treble Vodkas for five pounds. And also, if you find my iPhone, let me know. I lost it Newcastle 2011.

[Chris]
Yeah, I would look like I think we designed the course. So we could go around the country really. But then I realized that’s actually quite hard word to get out. But it’s nearly that’s over half sold, but some spaces left for that one in June. And then in, we had a lot of people want to get them down south. So we’ve got wanting, we do what foot in Hilton and near London. And there’s one there for September. So that’s it for this year. I’ve, they’ve done well. And maybe next year, we’ll try and do a bit more. But we’ve all got a lot of commitments. So we’re kind of, we’re doing that to begin with. But yeah, it’s been great. And it’s just a bit of a playground really to have a, on three days, lots of time, lots of little one on one chats and having to play around. And it’s, I think that’s what it offers, maybe the other courses, or I’m sure it may be do but that’s what we’ve tried to do. That’s different.

[Jaz]
Well, Chris, I’m so happy that I know you and Alan. I’m connected with you guys. Really, really humbled dentists, really great dentists. Just great. All round great guys, good in dentistry. Thanks so much for making time for this. I know you’re busy, family guy as well and all the things that you do. We appreciate this. And I can’t wait to bring this out. Ryan, I hope we smashed back to back Class II secrets. And I know that my Class IIs will be better tomorrow morning as well. So thanks so much, Chris.

[Chris]
Well, it’s been a pleasure. Big fan of the show. And to contribute is extra special. So thank you, Jaz, overall.

[Jaz]
Thank you so much, Chris.

Jaz’ Outro:
Well, there we have it guys. Thanks so much for listening all the way to the end. I hope you found lots of value there talking about all the nuances of back to back Class IIs. I know I’ve learned a few things, especially when it comes to liquidam as well how to not overzealously use it, which was something we mentioned as well. So if you liked this episode, please do share it with a colleague you know, these are tough scenarios, these back to backClass IIs, these adjacent Class IIs so please do share it with a colleague that may find benefit from it. And just let you know that the app is almost out. I’m so excited to bring this app out for you. The apps can give you a whole different way to experience Protrusive Dental Podcast to bring you more value. And for those who want certificates and actually get the CPD or CE verifiable hours you’ll have that option as well as so many other secret benefits which I’m going to reveal all in due course. Just let you know, just to whet your appetite that is coming soon. So anyway, I’ll catch you in the next episode. Same time. Same place. Catch you then.