Protrusive Dental Podcast by Jaz Gulati

November 26, 2024 Making Awesome Dentures – Border Moulding and Beyond – PDP205

What are the key steps and nuances to make awesome Dentures that your patients will love?

In this episode, Jaz probes Removable Pros legend Dr Mike Gregory to break down the process. From border molding to primary impressions and the teamwork between dentists and technicians, Mike reveals the key steps to making great dentures.

https://youtu.be/snM3PerQ1ko

For example, be sure to include a note on the lab sheet for the technician: “Preserve full peripheral depth and width of the sulcus on this impression, to about 2-3mm.” This ensures the correct functional width is maintained when the final tray or denture is created.

Protrusive Dental Pearl: When checking denture occlusion, it’s crucial to keep the patient relaxed. Mike suggests one simple trick: ask the patient to close their EYES before closing their teeth. This can sharpen their senses, helping to improve the bite assessment.

Need to Read it? Check out the Full Episode Transcript below!

Highlights of this Episode:

02:07 Protrusive Dental Pearl

03:31 Mike Gregory’s Journey into Dental Technology

10:09 Understanding Border Moulding

13:19 Technician’s Role in Denture Creation

15:45 Improving Communication with Technicians

18:34 Special Trays and Custom Trays

25:58 The Role of Green Stick

29:04 Denture Impressions

31:35 Boxing and Beading Techniques

35:08 Additive vs. Reductive Rest Seats

40:46 Guide Planes

42:43 Creating Undercuts for Dentures

45:10 Final Tips and Best Practices

48:54 Learn More with Mike Gregory

This episode is eligible for 1 CE credit via the quiz on Protrusive Guidance.

This episode meets GDC Outcomes B and C.

AGD Subject code: 670 REMOVABLE PROSTHODONTICS

Aim: To explore the intricate process of denture creation and provide practical insights on improving denture fit, occlusion, and collaboration between dentists and technicians.

Dentists will be able to:

1. Understand the key elements of denture creation, including border molding and primary impressions.

2. Learn the significance of maintaining peripheral sulcus depth and width in denture impressions for functional accuracy.

3. Gain insight into the role of special trays, custom trays, and impression materials in denture fabrication.

4. Recognize the importance of clear communication between dentists and technicians in achieving optimal denture outcomes.

If you liked this episode, you’ll love Suction Lower Complete Dentures – Improve your Removable Prosthodontics – PDP073

Click below for full episode transcript:

Teaser: This huge misconception that if you get suction on an impression, that impression is the perfect impression to make a denture. But you know, and I know if you take an impression, you fill somebody's mouth with algae, you get suction. You have to break the seal to get it out. That doesn't mean you've got the right depth.

Teaser:
It doesn’t mean you’ve got the right borders. You’ve just created a vacuum and that’s the worry that people create suction. I think this is it. This is going to be the great denture. But if you create suction, take the impression out of the mouth and look at it. It’s going to be big. You can picture this, can’t you?

It’s going to look big, it’s going to look like you’ve just pushed everything out the way. I used to think dentists were rubbish, which is really tough, but as a technician you’ve seen model after model that’s garbage. And then you think, these poor guys are taking impressions, but they don’t know what they’re doing wrong.

How do I do it better? If you were taught maybe not brilliantly as an undergraduate, or you didn’t love it as an undergraduate, so you didn’t really focus on it. How do you ever get better? You need to be re taught.

Jaz’s Introduction:
Let’s face it guys, dentures are a bit of a dark art. You only get so much exposure at dental school, and when you come to the real world, you’re faced with flabby ridges, resorbed ridges, patients with high expectations, and often you’re at the mercy of the impression materials that the practice has, and not the ones you were trained on.

Welcome to the crazy world of dentures, and I am absolutely stoked to introduce you to Mike Gregory today. So many of you have already seen his work on Instagram. His Instagram is like a free encyclopedia for dentures. I love how he’s sharing everything he knows, and this episode is no exception. We talk about border molding, like, this was so confusing using green stick.

I messed up so many times at dental school. I didn’t really know what the purpose of green stick was, or what it should look like if it was done well. But the way Mike breaks it down today, I think, everyone will understand and actually he’ll share his secrets. So you don’t have to use very much of it. Just in a few select areas, making our job even easier.

We’ll talk about nailing primary impressions and why your primary impressions should be overextended, but what’s the special advice you should give to your technician to make sure that the special tray is on point. And that you’re not having to modify the special trace so much. And like with many other episodes, we talk about communication and we emphasize the communication between dentist and technician.

So that we can benefit our patient with the best dentures possible. We also talk about guide planes and how they improve your dentures, but also rest seats. And Mike actually has some slightly different views about rest seats. Views which are very actually conservative, minimally invasive, and I think you’ll like this. How can we do more rest seats that are no prep?

Hello Protruserati, I’m Jaz Gulati, and welcome back to your favorite dental podcast. And this one is one of the geekiest ones I’ve done on dentures, and I absolutely loved it. My enjoyment of dentures has grown year by year by year. Initially found it very confusing, a dark art.

Now after going on some CE, some courses, I’m liking it more and more. It’s becoming, dare I say, predictable. And for someone like me who doesn’t place implants, I can also get that kick out of replacing multiple teeth. I guarantee you that if you make it to the end of this episode, you will improve your dentures. And if you’re on Protrusive Guidance, you can claim an hour of CE credit. So one CE credit or one hour of enhanced CPD by answering the quiz.

Dental Pearl
Every PDP episode, I give you a Protrusive Dental Pearl. And this one you’re absolutely going to love because it combines occlusion and dentures. Something taken from this episode. It’s something that I’d heard a long time ago, and I just got out of the habit of practicing it. And when Mike reminded me of this. I was like, whoa yes, I love this. I want to share this with everyone. So here’s the tip, right? When you’re checking the occlusion on dentures, let’s say complete dentures for argument’s sake, right?

So complete dentures are in, and we know that an ideal world, our condyle should be in a centric relation or a stable condylar position. It just helps to make sure that we are in a repeatable position. And so the tip that Mike shared with us is when you are checking the occlusion on complete dentures, of course, you get them to relax.

And in some schools of thought, you get them to tip their tongue to the back to try and encourage them to get to centric relation. But whatever technique you’re using, just do this one thing, okay? Get the patient to close their eyes. That’s right. The patient will close their eyes and then close together. And try it for yourself.

Please don’t try it if you’re driving. But if you’re not driving, then try it for yourself, okay? Bite together and then shut your eyes and bite together. It’s like with everything. When you shut off some senses, other senses get heightened. And who knows how much of a difference this makes, but it makes sense to me.

And I’ll be reintroducing this to my protocols for dentures. I may even try it for my dentate patients. If you’re someone who’s been doing this for years, please comment below. Let me know. And so with that, I’m not going to ramble on anymore. I really want you to get into this episode. You’re going to absolutely love hearing about his journey, but all the nitty gritty clinical details. You’re going to absolutely love Mike. I’ll catch you in the outro.

Main Episode:
Mike Gregory, welcome to the Protrusive Dental Podcast. I absolutely love what you’re sharing on your social media. I love your raw content. I love how much you care about helping people learn dentures and your selflessly giving of so many gems and pearls. It’s an absolute pleasure to have you on. How are you today?

[Mike]
I’m great. I’m really good. Yeah, I’m just conscious the dog might be set off in the background, but like you say, my content’s raw, so is my presentation. So if the dog’s in the background, it’s still authenticity, isn’t it? It’s just real world.

[Jaz]
Exactly. That’s a great way to describe your content and everything you stand for, everything you do. I don’t even know where you work. Tell me about your sort of work setup. Tell me about your love for dentures. I remember going to a Finlay Sutton course actually, and on his photos of you and lots of other people who’ve been learning the Scandinavian design many, many years ago.

And so that I came to my radar then as well. And with Rupert, and obviously just seeing your educational stuff on social media is absolutely mind blowing, but tell me a bit more about your journey.

[Mike]
My journey was, I knew you’d ask me this this morning. So when I was at school, I went to a pretty awful secondary school, didn’t even have a sixth form. And I loved making models, model aircraft, ships, that sort of thing as a child. And that’s all I did basically, until I’ve sort of got to 15, 16 and my mother, bless her, thought he’s going to have to do something I had no idea I wanted to do when I was at school. I really wasn’t bothered, as quite often boys are like that.

They certainly were back in the 70s. So I got into model making. Unfortunately for us, our family dentist, or for me particularly, our family dentist had a technician on the premises. And we’d seen our family dentist for years. Mom got talking to this dentist and said my son was going to do and he said, oh, it sounds like you might be interested in dental technology.

So I then spent a day when I was about 15, early 16 in the lab on the premises and it just blew me away. I thought this is model making in a different way. And I thought, this is great. And the weird thing was he had an apprentice. It was a year above me at school. So basically, there was a guy there I knew, and we just got talking. I thought, this is magic. So that was it. I thought, model making, I’m paid to do it. Great, let’s do it. So I just applied for two or three training places in London.

[Jaz]
You applied to be a technician, is that right?

[Mike]
Yeah, first I was technician since 1973. So I got offered a place at the London, which is now Bart’s. I got offered a place at the Eastman, and I got offered a place at Norwood Technical College, which is a purely technical college for teaching technology.

So I took the job at the London, and I just, at a fantastic four years and then with years consolidation. So we did everything up to qualifications that took three years. And then we did a year banner bridge, a year orthodontics, a year chrome, the year prosthetics. So I came out of that just loving everything.

And I was lucky enough to go to UCH. And then I did a two or three years there in the production lab working for the senior reg and that. And then a job came up in the prosthetics teaching lab at UCH. The tutors who teach students had to do the lab work, and I got that job, and I spent eight years doing that.

And while I was there, the student said to me, you should be a dentist. I left school at 16 with no qualifications, two equivalent GCSE grade C’s. So I then did my A levels at evening class, and applied to various schools, and eventually got into Bristol in 88. The 15 years as a technician, the final eight years teaching student, and they helped me get through my A levels. So that’s how I got to dental school, and then I qualified. I just love prosthetic even more, because I could now do both sides of it. So, I just had such a great start to life.

[Jaz]
I love your origin story, and I can’t name them all off the top of my head, but so many times I’ve been to, I’ve seen a great educator, and they have been trained as a technician first, and then a dentist, like for example, I don’t know if it has to be relevant in another order as well, but the first person that comes to mind is Ed McLaren, I’m pretty sure the chap who made digital smile design, his name is Christian Coachman, I believe as well, and my old principal, David Winkler, I’m pretty sure he was a technician first.

[Mike]
Oh, I know Dave Winkler, Dave Winkler’s, big friends with John Besford and John Besford is the guy who since 2010 you said you were talking just now and you saw that photograph of myself, Finlay Sutton.

If you look at the photograph again, John Besford’s in there, and that was back in 2010. We did a shot land. Of course. And that was such an inspirational course. I mean, Finlay wasn’t known. I wasn’t known. We were just guys who just liked dentures, who wanted to watch John work. And it was like, Oh my God, this is just another level.

You go on post grad courses, you must have done there, but when some courses are so special and everybody gels, everybody gets one, including the tutor. So at the end of the course, it was two days residential in Letchworth, where John treated a patient from start to finish. And he took his technician and John delivered a denture after two and a half days to his patient and everybody got such a buzz that we said in six months time, we’re all going to get together and meet up again and see how we’re getting on and compare notes. And it was such a good course. John Besford, world famous said, can I come along to that reunion in six months time? That was just something.

So in six months after we did the course, we all got together, including John. And again, the vibe was still there. And we said, right. We want to form a club so we can keep talking and keep meeting. Have you heard the story before or not? Maybe you haven’t. I don’t know. So basically, so six months after we did the course with John we met up somewhere.

I can’t remember where it was now. And John said, can I be part of the club? And then we all said, well, if that’s going to be the case, we’re going to call it the Besford Club. How nice is that? So our intention was then to meet every six months forevermore. And John said the only deal was and this is where me and Finlay got such a leg up, is the fact that he said, if we’re going to do this properly, you will find that people want to talk prosthetics, dentists will want to talk prosthetics to people who are passionate about it.

So John’s deal was we’ll meet every six months, but, and this was really stressy, he’s going to make us present to each other. As a group, you’d have to present cases to each other. And this John, John was speaking around the world at this point. That’s a massive amount, particularly for me, no formal training.

I mean, Finlay was the other guy, but Finlay had done his specialist training. So he got used to presenting cases, photographing everything. So the deal was every six months, we presented cases to each other. And that’s how I just upped my game. Photography wise and teaching my passion for teaching just went to another level and then Finlay’s the same now Finlay’s world famous now isn’t it as you know?

[Jaz]
And so are you my friend. It’s clear to see from your education they put out there but the story just shared is a really powerful story of mentorship of guided learning of having being inspired by someone who can spawn so many people’s careers in a way, right? And give you the inspiration. And also going back one step is, had your mother not had that conversation with that dentist that one day, had you not been inspired by the lab?

Had your dentist not had a technician on site? So one of my favorite books is Outliers and it talks about how Steve Jobs and Bill Gates are both born in 1955. They were around about the right age when it was all taking off to capitalize on it. And sometimes you have to connect the dots looking back.

You can’t connect them and looking forward. And so I think your journey has inspired. I mean, you didn’t know it was going this direction and that dental student to say you should be a dentist. So I love everyone’s origin story and yours is absolutely brilliant. Thank you for sharing it. Today, you’re going to be a mentor to all of us listening and watching the Protruserati all around the world.

They love episodes on removal pros because like occlusion, removal pros is a little bit of a dark art. And I love what you said that you are a tyrant when it comes to impressions. I’m looking forward to unpacking that.

Now, some of the questions I selected to make this episode tangible is border moulding. Now, before we start with border moulding, we can both agree that impressions are so important. I mean, every stage of denture is so important, but I was always taught at dental school by someone called Duncan Wood in Sheffield, that everything is like a pyramid. It was echoed also by Finlay Sutton when I’m in his courses.

Like the foundations is really great impressions. If you mess that up, then the next stage will be have a knock on effect. It won’t be as good. So if you get great impressions, you’re making a great start to it. So when it comes to making impressions, when we talk about border moulding, just tell us what is border moulding.

And then from there we’ll branch out. Okay. Is it important in both partial dentures and complete dentures, et cetera, et cetera, different material considerations, but start with a bare basics. What is border moulding?

[Mike]
I just think border moulding is a bit misinterpreted. I mean, border moulding, from my point of view, you want to get the functional so called depth and the width of tissue, so the tissue is wrapped around the mouth.

And border moulding is, I don’t think, people think, oh, you’ve got a slapped green stick everywhere. I don’t think that’s the case. I think you need to, and it all stems from primary impressions. Somebody in the group says, your primary impressions are your investment in the rest of the process. So, I just go back, I mean, border moulding is a recognition of functional so called depth and functional borders, not how much can you cram in somebody’s mouth and stretch everything.

This huge misconception that if you get suction on an impression, that impression is the perfect impression to make a denture. But if you take an impression, you fill somebody’s mouth with algae, you get suction. You have to break the seal to get it out. That doesn’t mean you’ve got the right depth, it doesn’t mean you’ve got the right borders, you’ve just created a vacuum.

And that’s the worry, that people create suction and they think, this is it, this is going to be the great denture. But if you create suction, take the impression out of the mouth and look at it, it’s going to be beautiful. You can picture this, can’t you? It’s going to look big. It’s going to look like you’ve just pushed everything out the way.

Border moulding is not just creating suction. Border moulding is recognizing functional so called depth and width, particularly on the uppers. And you record that. So it’s almost, it’s functional, but it’s passive. You’re not just trying to push some stuff in the mouth. You’re trying to get the tissues to wrap around it.

The patient does facial expressions. The patient moves their tongue. That’s what border molding is. People think border molding is take an impression, get a custom tray around, custom trays the panacea, with stick green stick around the outside, it’s going to be perfect. I think that’s what I think people think border moulding is.

[Jaz]
Totally guilty, totally guilty of that in the past especially. So here’s what I thought, right? I always thought that, okay, your primary impression, it’s okay for it to be overextended, right? Because you want to just record everything.

[Mike]
It’s desirable, not okay. That’s absolutely, that’s exactly what you want over, so that’s bang on.

[Jaz]
However, on the time, and this is earlier, like already, like I’m getting flashbacks to, at the time, I knew what functional depth meant, going all the way high up as appropriate. You don’t want to go overextended. You don’t want to be underextended. You want to be just right. But I never appreciated until a few years out of dental school, the width, the actual width of the sulcus.

I never appreciated how important that is to play. And you’ll obviously add to how important that is and how to capture that. But when it came to a prime impression, if I felt I was a bit underextended in the prime impression. I thought to myself, well, I can just make up for it in the special tray by using green stick and stuff.

So do you think that is unacceptable and perhaps we should just get aimed for an overextended prime impression every time? And then how does that relay into your special tray? How do you ensure that your special tray isn’t overextended?

[Mike]
You’re asking the exact questions you want everybody to ask. So underextension in a primary is quite often easily recognized by a technician. Classically, and anybody who’s listened to this has made any lowers will know, the tongue will be the bane of your life. It will get in the way, and it’ll stop you getting full sulcal depth lingually. And as a technician, you’ll spend your life pouring up casts of underextended primaries, and you’ll get something called a plaster chisel, or in the modern day, I didn’t use a plaster, I used to use plaster chisels, where you will recreate what they think is the correct anatomy.

Because technicians know what the anatomy should look like on a cast, within reason. So they’ll look at a cast thinking, guys missed the lingual extension. Let’s create a lingual extension for him. So they will then make a tray to their perception of where the lingual extension should be. And I had a classic line from one of the technicians at the old dental school two or three years ago now.

She said, if she hadn’t been a technician, she could have been a stonemason. Lovely quote. So they would recreate their perception of the missed anatomy that the clinician had recorded in the primary impression.

[Jaz]
Do you think this is standard of care amongst technicians? Or do you think it has to be a technician who is a bit switched on and likes this kind of stuff, who goes the extra mile to do it?

[Mike]
Oh no, Tracy was switched on, she knew. Of course, the other thing is, it depends how you’re trained. If you’ve never been trained in a good establishment, like I was at the London, which is now Bart’s, you didn’t really see beautiful impressions day in, day out, to then spot the one that wasn’t so good. So that’s the hard thing.

If you’re a trainee in a plaster lab, just pouring up models and nothing else, and some of the big commercial labs, almost certainly like that and I’ve got examples where you know you’ve looked at casts and the lab have made almost routinely overextended all the impressions on the assumption they’re all underextended. So you get an impression there’s a tutor somewhere teaching these trainee technicians or process workers, they call them.

Take it for granted, all these models that impressions will be underextended. So just make all the sulci bigger everywhere. Which then means you’ve got almost man made guesswork peripheries, but then they make the trays to those guesswork peripheries. So you get the tray out the bag and I’m afraid a lot of clinicians think oh, that’s the panacea I’ve got a custom tray.

I’ll be okay now and some guy up north in I was lecturing up at newcastle. He said if you take an awful primary and make a tray on it, the custom tray you get is a glorified stock tray because the peripheries are still guesswork. So it takes your technician to recognize the anatomy But if you want to see what you’re on, this is tough on clinicians.

If you want to get better at your impressions, ask your technician to photograph the model as poured and send it back to you. And you’ll look at it and thinking, oh, it doesn’t look like that in the mouth. Does it? But see, most of the time clinicians will get back models that the lab have doctored and done the tracing thing of stone macery and make them look real.

So it almost flatters your primaries because you never see the raw poured model. You see the poured model that’s been titivated, you’ve got some sulcite you didn’t have, you’ve got some anatomy, you’ve got some gingival. Is this all making sense?

[Jaz]
Yes, absolutely. Yeah.

[Mike]
Basically, you never see, if you want to get good, get your technician and say, look, just take a photograph. What’s happened with the picture of my model before you make it look better, or better still send the model back unadulterated, and you’re looking at it and thinking, I’m not as good as I thought I was. That’s what goes wrong. Technicians make clinicians think they’re better than they really are. It’s a bit sad.

[Jaz]
Well, I think it’s a great moment to just pause and reflect on this top tip, because a lot of people will just listen to it. They’re driving and on a train, they’re running and not take action. I think before we even had that kind of level of relationship with your technician, so many colleagues don’t even know the name of their technician.

Right? So, and I say this all the time, time again, make a relationship with the technician, find their name, be on WhatsApp terms, be on Instagram terms, be on email terms, whatever, right? If you can have that relationship where they can send, take a photo on their phone and send it to you and have that trusting relationship to give you the critique, you’ll absolutely fly.

[Mike]
Oh yeah, definitely. And better still go and see ’em.

[Jaz]
Oh, a hundred percent.

[Mike]
Take ’em a packet of hob knobs. Sit down with ’em.

[Jaz]
Take some pork scratchings. Get a coffee.

[Mike]
Exactly. Sit down with ’em. And just say, tell me what drives you nuts. From a technician’s point of view, you should say, as to a clinician, I tell you what drives me nuts. And you’ll see it. If you go to the lab, you’ll see the stuff they get in. I used to go to my lab and I’d say to the guy who used to run it, I said, you got anything I can photograph today? And there was always stuff. And I used to think dentists were rubbish, which is really tough. But as a technician, you’ve seen model after model is garbage.

And then you think these poor guys are taking impressions, but they don’t know what they’re doing wrong. How do I do it better? If you were taught, maybe not brilliantly as an undergraduate, or you didn’t love it as an undergraduate, So you didn’t really focus on it. How do you ever get better? You need to be re taught.

[Jaz]
But also we’re not doing the numbers, like even at dental school, like, I mean probably it’s different for when you teach, but because you encourage them so much, I imagine. But the numbers that we’re doing, like complete dentures almost now, a postgraduate discipline is the way it’s perceived, because we’re not doing enough numbers. How can you become good at something if you’re not doing enough of it? And dentures very much falls into that category.

[Mike]
Oh, it does. I mean, this is why I run that course with Rupert all the time, Impression Club. We’re running another one tomorrow in Bart’s. Every time we put them up, we get 15 people want to come in. And all we do is primary impressions. We do nothing else. It fills a whole day. And people go away thinking, Oh my God, I know I want to do this. I want to go back and do it. Of course, the great thing, you’ve got a really selective audience then, whereas undergraduates, some of them are interested and some like, oh, I don’t know.

And of course, if you’re lucky, like John Besford did with myself and the rest of the group, it just inspires you. So if you’ve got somebody who loves teaching it, and I have to say it’s slightly difficult. Because some teachers in schools nowadays are thrown in at the deep end. Like, can you teach prosthetics as well? I don’t really love it, but yeah, if you like. And, if the passion’s not there, it’s difficult, isn’t it? Difficult getting teachers.

[Jaz]
That is true, but I’m glad that you have entered that space, and you’re doing that, fulfilling that. Now, back to the special tray. Great point, making sure that your primary impression is overextending away, so they get the full anatomy.

And based on that, when a technician has the model, right? Because now they’ve gone overextended because we want to see all the anatomy, what guidelines are they using to make the special tray to make sure that the special tray is about right and it’s not overextended?

[Mike]
I had a light moment. I used to do a bit of freelance work when I was working in the hospital. I used to work for, do clinical work for a good friend of mine who was my tutor. And I made a custom tray for this lady. And I thought I was really good as a technician. You would, wouldn’t you? But I was actually deemed okay. So I made custom trays the way we were taught. And classically, we’re all taught, you remember this. Make your custom tray 2mm short of the primary sulcus extension.

[Jaz]
That’s right.

[Mike]
But what I didn’t know, as a technician, you’re troubling with education in this country, probably around the world. Technicians are taught by technicians, agreed? Where’s the overlap? So when you start to get feedback, so this lady drew this diagram of a cross section through an upper tray, and she was showing me that her impression was really good, the primary was hugely overextended, which is great.

But then I was doing what the textbooks tell you to do, make the tray two millimeters short. But what the diagram showed me was the fact that two millimeters short of a massive degree of overextension is still massively overextended. And that’s the light bulb moment. As technicians, you never see mouths or rarely will you see a mouth to know where that line is, where your custom tray stops.

And I think as a technician, you’re never going to get that unless you start to be really talking to your clinician. So if you want to do this properly, what you should do, and I think this is easier than people think, is take your great primaries, and you have to use compound, you have to use green stick.

That was one of your questions. I don’t use putty, but you have to take a really good primary, overextend everything. No technician will ever say, you’ve sent me an overextended primary. It’s never going to happen, okay?

[Jaz]
And just back to basics, because loads of dental students do this as well. Like, for primaries, your alginate is still the choice of impression material for primaries, right?

[Mike]
Yes, but you have to modify your tray first. Nobody should ever take a stock tray impression for anything, in my view. Prosthetics, the John Besford’s classic words, prosthetics is the only branch of dentistry where you take impressions of the gums as well as the teeth, because you need the gums as much as the teeth.

So if you don’t modify your trays, which is the build it course with Rupert, and modify the trays with compound, green stick, and wax, and the mnemonic for that. Somebody, I was lecturing in Manchester a couple of years ago, and people always ask, what order do you do it in? Green Stick, Wax, Compound, which order? And somebody in the audience said, Can’t go wrong. Can’t go wrong is a mnemonic.

[Jaz]
C E G W.

[Mike]
Exactly. Compound, Green Stick, Wax. And it’s just, can’t go wrong. So I now say that to my students. They’ve got two expressions they have to learn from me. Can’t go wrong, which is new. And the other one is maximum support, minimal gingival coverage.

But can’t go wrong for impressions is the answer. So if you take a primary impression, you should look inside your tray and there should barely be any visible tray showing the peripherals are either going to be in compound, they’re going to be in green stick, or they’re going to be in wax, and that’s how you do primaries. That’s how you get full extension and too much extension. So, that’s going back, that’s what you do.

[Jaz]
But then how do you solve that problem of the technician or guiding your technician to make sure that your special tray is about the right place?

[Mike]
So, what you’ve got to do then, and you can’t expect technicians, you can’t describe to the technician make it 2mm short, 3mm short, because the 2mm rule, I say to students day in, day out, if you’re doing an exam, and they ask you where should your custom tray extend, always trot out the 2mm rule, because that’s what the examiner’s looking for.

It’s garbage in reality, because if you want your custom tray 2mm short of your primary extension, which is what everybody says, does that not then follow that your primaries have to be precisely two millimetres overextended? So the two millimetre rule is a textbook answer for a written exam.

In reality, it’s rubbish. Because I can’t control overextension, nobody can. You just push everything out the way. So the only way you can do it in reality is and as clinicians, you look in the mouth, you can see overextension. I was talking to a guy who was due to qualify two or three years ago. Really nice guy, he’s down in Devon now.

Taha, he won’t mind me mentioning this. We were talking one night on Instagram and he said, I don’t get it. Where do you extend the tray? I said, look, go in the bathroom, wash your hands, pull your lip out the way. Seriously, and move the soft tissues around. You’ll see the attached, unattached mucosal junction. You can picture that yourself, can’t you?

[Jaz]
Yes, absolutely.

[Mike]
And he came back two minutes later, he said, I’ve got it. I’ve got it. Exactly. There you go. That’s what you do. If you start to look at that, you’re going to think that’s a light bulb moment. So what you’ve got to do then is you’ve got, as a clinician, start looking in the mouth and look at this and you’ll see it on the cast.

So take your primary, overextend everything, and say to your lab, I think most of us work with couriers, and most lab is two weeks between lab work, so the lab will pick up the lab work the day you took the impression the day after. They’ll pull the model when they get it back, agreed? And what does that model do then for two weeks or ten days?

Sits on a shelf, waiting for the technician to pick it up and make the track. So why don’t you ask for it back? So can you send the model back in two days time? And then you’ve done your mental photograph, and you start to look at casts. And you’ll see the frena. You’ll see that attached, unattached mucosal junction.

And you draw a line on it. And when you’ve drawn a line on it, you then send a model back to the lab. Which is, you can do that in your coffee break, in your lunch break. Courier then picks the model up, goes back to lab, still sits on the shelf for three or four days. Technician then picks it up and looks at it thinking, oh, that’s where he wants the tray made to. And that’s how you get tray extension. And that’s how you start to spot what anatomy looks like in the mouth, and the technician then starts to get on your wavelength of what it should look like.

[Jaz]
Two questions there then, should the technician not have adequate experience and judgement to be able to decide that, or does it need to come from the clinician, you think?

[Mike]
I don’t think so. I was 15 years as a technician, and then I started clinical, and I was just doing as I was told, and then it was almost after I qualified that I worked this out. So I just think, if you start to work with your technician on a regular basis and do these lines, they will start to do a lot of it for you. It’s too much on the technician to expect them to get it right.

[Jaz]
It’s a great, it’s another touch point for the clinician to be involved in the process, and I think it’s wonderful. Here’s an idea. When Mark Bishop taught me complete dentures at dental school, I remember on my alginate getting an indelible pencil and drawing like a line.

I’ll be honest with you, at the time, I don’t know why we’re drawing the line, but we’re drawing a line in the peripheries, right? And then basically, when the model is being made, the pencil would embed in the model. And so can you actually look at the alginate and deduce where this line is? Can you actually put the pencil line there? So it kind of kills two birds with one stone and then you don’t need to have it back. Is that possible?

[Mike]
Love the question. And this is where we as clinicians assume people can do what we can do. We’ve been doing it for decades. They’ve been doing it for 10 minutes. So in theory, a skilled clinician who’s done it for a long time, you’ll be able to know exactly where to put that line. As a novice, who’s made one or two completes in dental school? I don’t think you can do it.

[Jaz]
So it’s easier on a model than on an impression.

[Mike]
Massively, easier on the model. Because you’re not looking at the reverse. You’re looking at a solid version of what you saw in the mouth. So you might be able to do it after a few years of experience. But as you said, as a student, you’re thinking, What the hell are we doing here?

[Jaz]
I had no idea what I was doing. I was just doing what Dr. Bishop told me to do. And he is a fantastic educator, by the way.

[Mike]
And the logic is completely sensible. The logic makes complete and utter sense. But that’s where the skill of, and you can’t beat years, can you? Years take their toll, but the years have the benefits, don’t they? And the benefits are, you’ve seen everything, and you know where those lines should be. So if you’ve done it for a few years on the cast, you can then do it on the impression. But by that time, if you’re lucky to have the same technician, they’ll know what to do anyway. The bottom line is, look in your mouth, look in the patient’s mouth, look at your cast, and start drawing some lines, and you’ll get some amazing trays.

[Jaz]
But the line you want to draw is at the very limit or you want you still want to have that, no, yeah, it should be at that area not two millimeters below tiny bit short.

[Mike]
Tiny bit short-

[Jaz]
To allow for the thickness of the impression material.

[Mike]
Exactly. We were talking completes before we went live and if you’re doing completes and you’ll probably say agree with this that nowadays, sadly, we’ve got so many patients with massive resorbed ridges.

You don’t want space trays. You want close fit trays. So if you draw a pencil line and the tray ends just a fraction short of your eventual sulcus that’s just enough for the impression to roll around. That’s the way.

Interjection:
Hi guys. It’s Erika here, the producer of Team Protrusive. I’m just interjecting here with the announcement that you’ve now got this amazing community platform. You can access it from your laptop. It’s called Protrusive Guidance. There’s also a native Android and Apple app. What we really want to do is to harness the power of the Protrusive community and create a platform you can share and grow together. And you know what? It’s way better than Facebook. So if you haven’t already, check it out!

Just do bear in mind that we manually approve every single application. So it might be a little bit slow to approve you. But we only want dental professionals on this network to keep it a safe place and so that we can share failures together. Head over to www. protrusive. app to know more.

[Mike]
Way it works. So you’re right, we’re all taught to green stick all the way around the edge of a tray. When we were undergraduates, do you remember that? I was taught the same thing. Green stick your custom trays for complete. And it took me a good few years, I probably only worked this out 10 years ago. They would, all the clinicians would do it, the tutors. But what I’d forgotten what they used to do, they used to take your tray out the bag. And I remember tutors doing this at Bristol.

[Jaz]
Let me guess what you’re going to say, they took the tray out of the bag and they start trimming away the special tray to only rebuild it with green stick? Is that what they did?

[Mike]
Absolutely. But what they were doing, what they were doing, I didn’t realize, they were making room for the green stick. And what’s got lost in the translation over the years is take the tray out of the bag, and then add the green stick without making space for the green stick. That’s what’s gone, and that’s what they used to do.

But the problem with that, with doing green stick all the way around, is if you’re a genius with green stick, going back to experience, You could green stick all the way around the periphery of a tray if you’ve made one and get beautiful functional so called depths, but if you’re a novice and you use green stick what once a month once every three months Are you ever going to get the skill to green stick the periphery of an entire tray? It’s not going to happen, is it? So it goes back to get your trays right and I do so little green sticking.

[Jaz]
That’s exactly what I was going to ask. So once you get the skill right, of getting the model back, drawing where the special tray should be, by getting in the right place, it negates, almost negates the need for the green stick all the way around.

[Mike]
Absolutely, 100%. 100%. So all you do then is you, and we were talking about this earlier on, you record the functional width with the green stick. So classically, when we get an impression stuck in the mouth, dentate or dentures, what do we do? Stick your finger down the buccal sulcus, pull the cheek out of the way to break the seal. So it’s not the depth that’s creating the seal there, is it? As you said, it’s the buccal width. So that’s where I green stick buccally in the sort of the two brossy regions.

[Jaz]
So you want some thickness, some buccal thickness of the impression around the back, and it’s great to capture that with the green stick, because if you rely on the impression material, do you think it’s not viscous enough to capture it? Is that the worry?

[Mike]
It’s not, and sometimes you just need to create a little bit of space. And if you do capture it, and your custom tray was a tiny bit short, you then got unsupported impressions at the peripheries. Because I think classically, clinicians look at an impression thinking, I’ve got great depth there, there, and there.

But it’s alginate that’s moving around, or it’s silicon that’s moving around. Now again, as a technician, and clinicians were technicians, and I’m so lucky I was, you realize when you’ve got moving peripheries, when you pour the plaster into the model, into an impression, they all distort. So you’ve got the right depth, but if you haven’t got the rigidity, I did a post on this recently, if you haven’t got the support for the peripheries, they’re going to move when the lab pours them up. So you’ve got great depth, no stability, inaccurate when poured. So that’s where the green stick, you need to support, which is where green sticks great.

[Jaz]
Well, I use pink stick and I loved it because I was a trainee at Guys in restorative. I was introduced to pink stick. And for me, the few times I used it, it just felt like a nicer, more pleasant cousin of green stick. What do you think about pink stick?

[Mike]
To be honest, I’ve never used it. GC make it, don’t they?

[Jaz]
I think so. And you know what, Mike, I absolutely loved it. It was just like, it just did what you wanted it to do. Everything you want from green stick, except Yeah, exactly. And so it was great. So, pink stick from people who’ve used it before they tend to agree. So something for you to try out and let me know how you find it because I’m more interested in what you think.

[Mike]
Well, if you’ve got any clout with GC, can you get them to send me some because I’ve tried and tried and it just doesn’t turn up. It’s difficult to use.

[Jaz]
We’re going to get GC to send you some pink stick to use and talk about it. I’m sure they would love the exposure and other brands are available as the BBC says, right. So we’ve got to a situation whereby you’ve got this perfectly correct height of the special tray, the width we’re getting with the green stick stroke pink stick when GC sent it to you, and then the rest of it, are you relying on the rest of the borders, the functional borders, to come from your impression material?

Now, I don’t want to go too much into impression material because that’s it. Podcasts will then forever be about different impression materials and whatnot, but generally speaking, let’s now focus on complete denture case. Let’s say we’re using zinc oxide, you know, are you a fan?

[Mike]
Absolutely.

[Jaz]
Okay, so let’s say we’re using ZOE. Are we relying on the ZOE to get the rest of the functional borders, or are you also reinforcing the tray more so?

[Mike]
I rely on the impression material, which is why alginate doesn’t work for it, because it’s not viscous enough. So, zinc oxide used, no medium bodied silicon, absolutely fine. But you just made it the tray, because the tray is virtually at the periphery you want, it doesn’t matter, because you’re only going to have a millimetre or maximum, which is going to support itself. So whatever material you’re comfortable with, which is why then we’re not going to get on to materials, as long as you’re comfortable.

But you have to learn to manipulate the tissues, and the patient has to pull the right facial expressions, the patient has to move the tongue, the patient has to swallow on the lower, and that’s where you get your borders from. And the other thing to do-

[Jaz]
Can you go over there and say ooh? Eee, and wiggle your jaw side to side.

[Mike]
Yeah, you have to wiggle the jaw to get and you do the wiggling of the jaw when you’re green sticking, because otherwise the coronoid process tissues overlying it don’t actually get the right width, and that’s what you have to do. So I try and teach everybody. You’re doing maxillary impressions, mandibular movements.

[Jaz]
I had a patient who, I did, I perhaps didn’t do enough of this, and he came back, complete denture was otherwise good, but now and again it was just the seal was just breaking, okay? And what I had to do is identify that, okay, it was too wide. The sulcus was actually too wide in that area, and the coronoid was just knocking it off, and by thinning out that area made a huge difference, and so we can reduce that, the need for that, by getting it right in the impression stage, or the green stick stage.

[Mike]
So important, and people underestimate the importance of the width. Going back, quick flashback, when I was a technician, I used to look at some of these impressions thinking they’re really fat buccal flange on these dentures. I thought the patient won’t like that. I used to thin them out, thinking I was doing people a favor, and you’re thinking, actually looking back, I was doing nobody a favor.

If they’ve recorded right, they might not have done functional widths, they might have just filled the mouth up with but so yeah, so technicians, and the critical thing now we’ve touched on this is, if you do all these borders, your technician has to preserve them all. Because the big difference between primary and secondary impressions, if you overextend primaries, it doesn’t matter if you cut the peripheries down.

You’re not making it deeper, you’re getting better access. And technicians will tell you this, but when you’re doing secondaries, you have to preserve those borders. So the standard line on the lab sheet should be, preserve the full peripheral depth and width of the sulci on this impression, to about 2-3 millimetres.

[Jaz]
Everyone should memorize that, and we’re going to put this in the premium notes because this needs to be a line that you use, because, again, when I was a DCT at Guy’s, I was learning this. The term boxing and beading came up. My tutor said to me, if you don’t write that, technician might not do it, and then you won’t preserve it. Can you tell us more about boxing and beading? Is that still the right words?

[Mike]
I used to do boxing and beading as a student technician. And that was the way we routinely. The great thing about being a trainee technician at a teaching hospital is you get the best teaching as a technician. So all the second impressions those days were done with zinc oxide eugenol. So we would box and bead every impression.

[Jaz]
Can you explain what that is? Cause at the time I had no idea. I’ve got a vague idea now, but I’d love to hear properly from you.

[Mike]
If you’ve got an upper impression taken as Zinc Oxide Eugenol, you would draw an indelible pencil line on it at 2-3mm from the periphery up the outside of it, so that’s at the buccal aspect, and then you would stick some ribbon wax, soft ribbon wax, strips of ribbon wax, you would stick that at 90 degrees to the impression, all the way around the periphery. So you create like a rough, does that make sense? Like a border. It’s two or three millimetres up. See, now that so, and the boxing was then you get a sheet of wax and wrap it around.

[Jaz]
So the beading was the wax bit, was it? So the ribbon wax is the beading.

[Mike]
The beading is the horizontal tangential to the buccal flanges. And then you’d sort of encase the whole thing in sheet wax, so you’ve made like a mould, and then you’d pour in. So that was boxing and beading, but you say that to a student, you might as well not bother. And the other challenge we’ve got nowadays is, so classically zinc oxide’s great because wax stick.

Wax will not stick to alginate, and wax will not stick to silica so you can’t box and bead. So you right in boxing and beading to most people it’s just gotta above their head. You have to say, preserve peripheral width and depth in whichever manner they want. Do it in the lab and that’s the way you get it.

So boxing and beading is historical, it’s in oxide, used all done in schools. You can get putties to do it within instead. Some labs use plaster seed. If you Google it, it’ll come up. Alright. If you’ve got a good lab, they’ll get it. But a lot of technicians, bless them, aren’t taught by old school technicians or clinicians to preserve the peripheral width and depth. And that’s the crunch too.

[Jaz]
Great point there. That actually. The process does not matter as much as the outcome and the outcome being as long as the depth that you’ve worked hard to create and the width that you’ve, you know, created should be preserved and copied onto the denture because what a waste of time with your green stick if that’s not preserved.

You don’t get that width and so that should be standard. Now I’m just going to look at my questions again because I’m absolutely loving our conversation and I don’t want to miss anything. So my next question is, how important are the skills when it comes to, let’s say, a tooth borne cobalt chrome denture, which has some flanged areas, are we still aiming for this, or are we saying that actually just thin it out and that getting the functional width and the height is not as important?

[Mike]
Everything, do it the same. If you adopt the philosophy, it’s always going to be get the depth right, get the width right. It doesn’t matter what you make, your mindset will be just get it right in the first place. Did you mention scanners in your thing?

[Jaz]
I did mention, but what I’m going to ask you soon is, after you answer this one, is how can we benefit in the digital workflow with border moulding?

[Mike]
I want to turn this around then, before you ask about the prep, if you take a beautiful analog second impression, I trust scanners to scan the impression. So you can preserve the full peripheral depth of width because you’ve scanned it. So if you take beautiful prime secondaries and you scan them, you’ve actually preserved.

I’m not because I don’t do it. Okay. So we’ve got prime scan. We’ve got two or three in the practice. I just like models and I’m old and it’s like, can you change a dinosaur? It’s difficult. It’s where it works. But where scanners won’t work is recording the functional depth and width. Because how do you stick a camera in the buccal sulcus and get the patient excursed to coronary press? Never going to happen until AI gets massively more clever than it is. So that’s, scanners come in for completes because you can scan. So take beautiful, this is where you get the interaction.

[Jaz]
Scanners are not there to replace your beautiful impressions, but they’re there to digitize that impression and then preserve.

[Mike]
You can preserve forever more. You beautiful secondary, your analog is preserved digital. So that’s a lovely marriage. I think that works. So you can’t separate the two. I don’t think. So going back to tooth prep, I came up with a question for the student and the old days used to get a line of texts and say, discuss.

And I said, how do you accommodate rest indentures? Do you prepare or do you not prepare? And the bottom line I was trying to get across the students that preparation for rest seats can be additive, which I don’t think enough people do, which is composite on lower anterior teeth, for instance, or it’s reductive when you plunge burs into lovely teeth, which is just sacrilege.

See, I just don’t like the prospect of wrecking marginal ridges to put occlusal rest seats in. If you classically got two molars, together. They’re nature’s teeth, and you’ve got intact marginal ridges. Do you really want to cut rest seats into those? Wreck the contact point. It’s back to life. Patients might not love what you make for them, agreed?

You can make them a denture, and if they don’t like it, and the rests sit in the rest seats that you’ve prepared, and the marginal ridges, and you’ve, God forbid, broken the contact point. If they don’t wear your denture, you’ve now got an open contact point. So when we’re talking rest seats, additive is beautiful because it’s non invasive, and worst case scenario, you just grind them off, but invasive.

So I always try and encourage the students, because classically, I think as a profession, we tend to look at the arch we want to restore, and if it’s a partial, I can fill those gaps with a denture. I need to put rest there, rest there, to support the saddles.

[Jaz]
We need to look at the opposing.

[Mike]
Exactly. Do we look at what’s opposing? Can we sacrifice a little bit of cusp tip, which is thick enamel? Do we really want to go into marginal ridges?

[Jaz]
That’s a wonderful point. And I think term I use when I’m teaching occlusion stuff, I talk about Robin Hood dentistry, stealing from the rich and giving to the poor. So stealing from that very rich perspective.

[Mike]
That’s nice. I can use that next week.

[Jaz]
Please do, please do. And so I like, I love doing this, especially when you’ve got like a plunger cusp, and like you’ve got a crater, a opposing tooth, typically a lower, and to just smooth and recontour that plunger cusp to give you that space you need to restore. And in the same vein, I love what you were saying here, whereby, what I was thinking when you’re telling me about being additive for your rest seat is that, well, if you haven’t got space opposing, then how are you supposed to do that?

But you just said, you can be strategic a lot of time to create a bit of space by doing a dirty word, which is enameloplasty. But actually, if we do it safely, then, in a well planned way, then it’s a great way to do it.

[Mike]
It is. I mean, this just highlights, because lots of people say, we’re now trying to indoctrinate the students to do primary registration. If you’re planning a denture, if you’ve got freehand saddlecast, you can’t hand articulate freehand saddlecast. Mount your primary cast, and then you’ve got all the views you haven’t got in the mouth of where you can put rests. You can see, looking up from your esophagus, oh, there’s a room there. There’s no way you can see it in the mouth, buccally.

So exactly, planning is so important. And then you work out, are you going to additive? You’re going to do reductive. And can you do it, do it nicely, safely, and with less detriment to the patient? So that’s the way you do it.

[Jaz]
I want to mention to, for all the guests, I mean, I know you know what equipoise dentures are, but have I said it correctly? equipoise, have I said it correctly?

[Mike]
Yeah, yeah, yeah, yeah.

[Jaz]
So equipoise dentures, I came across them about, 10, 11 years ago, and essentially you’re doing it so that it’s a chrome denture and you’re basically cutting a lot of teeth in the sort of embrasure areas, rest seats to basically make it a really tight fit without any clasps. Have I got that correct?

[Mike]
Absolutely.

[Jaz]
And so based on what you just said, I think you are in the camp who is against equipoise dentures because actually it’s drilling into these embrasures and rest seats and stuff. What do you think?

[Mike]
Yeah, funnily enough, we had a guy who was really pro equipoise in the Besford study class.

[Jaz]
A Scottish man, by any chance, Edinburgh?

[Mike]
He was actually, yeah.

[Jaz]
I think I know what you’re talking about.

[Mike]
He’s now retired. Anyway, but the way he described them and the function was just amazing. The retention was just brilliant. But it just struck me as carnage on teeth. I felt like I wanted to do them, but I couldn’t bring myself to stick bur.

I hardly ever use a turbine for anything at work. And I do nothing but dentures now. I hardly ever pick up a turbine because I just don’t want to. And we’re talking about guide surfaces. Can I talk about guide surfaces for a minute?

[Jaz]
Oh, please. So one of the questions I had for my guys is. Talk about rest seats. And I love this gem he shared. I think will really resonate is how can we make it so we can be additive in rest seats? So that’s a great point there. Also using composites, as you mentioned, so make that a bit more tangible. The way the composite would work, for example, is like adding cingulum rests on the upper palatal incisor, right?

[Mike]
Much more so on lowers because the cingulum on the lower is. It’s so steep. If you make a lingual plate or anything like that, I mean I use this horrible analogy just to make people focus. If you make a lingual plate without support, that lingual plate acts like a cheese grater on the peridot and tissues, lingually.

And it’s just a hideous concept. But that’s what’s going to happen. We know these lingual plates will just drift, and they just strip the soft tissues away. Those cementum caries, perio damage, it’s awful. So classically, if I ever see a case and you’ve got three to three standing, same with students, there’s no way you’re not going to add six lingual composites to those teeth. I just want that dentures to just don’t drift lingually.

[Jaz]
So this is like the standard, you have to find a reason not to do it. So it sounds like composite on lower incisor lingual surfaces as little cingulum rests, if you like, additive rests, if you like, a great idea to prevent the slippage of the metal.

[Mike]
Absolutely. So the four lower incisors and the two lower canines, if that’s what you’re left with, you put composites on them. The only downside to that, and I have to say this to people. It’s potentially going to be in the way of your existing denture. You have to do this. One is it’s going to feel funny to the patient’s tongue and you warn them. And the second thing is potentially the current denture might not go back over them, but most of the time that current denture is a few years old and it’s drifted south and it’s gone below the points where you’d had your composite soreness. That’s not an issue. And this is where generations are different. John Besford says, well, just adjust the present denture. But what if your denture’s not as good as their old one?

[Jaz]
I love how cautious you are. You’re a man of your own heart. I’m very ultra cautious when I’m adjusting things, including people’s old dentures and stuff, and I think you’re the same.

[Mike]
So just be careful, because if you’ve then adjusted their old denture, and they say the new denture’s not as good as the old one, but you’ve wrecked the old one, what do you do? You’re stuffed. You’re really up against and it’s the same, this is what I was going to say, so if you’re going to do that, but quite often, as I say, the existing limbal plate has drifted so far south.

You just take a mental photograph, again, like the function of the sulcus. See where you can put your rest seats in composite. And can you place them above the current denture? And if you can, fine. And most of the time, very seldom can I not do that. This is, say, about affecting the current denture. We’re talking about contact points next, which is what you brought up.

[Jaz]
Guide planes.

[Mike]
Guide surfaces are just beautiful. Bit equipoised, but not so invasive. The problem you’ve got is exactly the same thing. So if you’ve got a patient with a pre existing denture, And the contact points are all intact, and then you start to create guide surfaces on the proximal surfaces. What have you done to the present denture?

You’ve trashed all the contact points, you’ve trashed all the stability, and again, if your new denture’s not as good as their old one, or something goes wrong, their old one’s slopping around, they don’t like their new one, again, invasive, irreversible dentistry. So the only time I think you can be 100% sure that tooth prep for a new denture that’s not going to cause an issue is when you create buccal undercuts or lingual undercuts because again that’s not going to stop the old denture going in.

Quite often it actually makes the old denture better until you’ve made the new one and you can run them off. If you’re doing invasive dentistry just be careful because existing dentures might not be as good as they used to be and if the patient’s at all difficult you can’t really argue your point that I had to do that I told them it might be a case. I think from a defense point of view, you’d be up against it, wouldn’t you?

[Jaz]
So just make that point a bit more tangible for me. By buccal and lingual undercuts, you mean just utilizing them for your-

[Mike]
Making them a flowable composite.

[Jaz]
Understood, now I got it. Okay, you don’t do guy planes so much?

[Mike]
Very seldom again, because it’s irreversible. If the patient’s no pre existing denture, doesn’t matter.

[Jaz]
Or a crappy denture.

[Mike]
Or a crappy denture that’s got no contact points anyway, which is, then it’s fine. Or if you’re going to make some crowns, build the guide surfaces in. So I’m not saying don’t do them, but just proceed with caution if they’ve got a pretty reasonable decent denture at the moment.

Just tread carefully. So if you’ve got proximal surfaces, I mean classically a lower posterior saddle, bounded saddle, guide surfaces are great for that. And if you’ve got gnarly old amalgams and MO on the seven and a DO on the four, it doesn’t matter, does it? You just skim a bit of an amalgam back.

Beautiful. But again, your technician’s good at giving you some feedback, telling you could do, make a much better denture, reduce the stagnation area, all sorts of stuff. Again, go back to the beginning, talk to your technician.

[Jaz]
I personally like guide planes a lot. But I realized that all these cases I’ve been doing it are new denture wearers, or they had got crappy dentures, or I am adjusting restorative material, be it composite, being an old restoration, or I’m doing some crowns in the adjacent teeth, and I’m building that into it.

It’s about the planning, as you say. Now, it raises a great point about creating undercuts lingually, buccally. Let’s imagine a lower premolar, lower second premolar, and it’s very flat, buccally, like it’s very, very flat, and you want to create an undercut. Can you give us some advice in terms of how to do it? Because for beginners it’s difficult to visualize exactly the kind of shape you’re trying to make.

[Mike]
Oh, this is where planning with your technician. Say to a technician, look, I want a class B’s lower fives, because some clinicians can visualize undercuts on teeth and some can’t. If you look at a cast, some people say, well I can see it’s undercut. If you’re not sure, say to your technician, I want a class below five for instance, get the technician to survey your primary cast for you and say, have I got enough undercut on those teeth?

Because if you haven’t, the technicians will chase undercuts at the cervical margin, and then they’re putting class IIs cementum, which is really bad news. So if you want to make buccal undercuts, they take seconds. Flowable composite is just beautiful. I say to the students, you make a fried egg.

Buccal, composite and flour. You don’t polish it, you do nothing with it. And if you’ve never done it before, don’t etch, don’t bond and practice. Put some composite on the tooth. But it needs to be a fried egg. It’s no good making like a hard boiled egg cut in half. If you’ve got a distinct pimple, you won’t get the class out from underneath it, or you’ll break your fingernails as the patient, or you’ll break the clasp. So you want a fried egg, and there’s posts on my Instagram, you can go back and see them. Fried eggs make beautiful undercuts. And flammable composite, it almost doesn’t matter what shade it is, because you’re creating what, 0. 5 of a millimetre undercut?

The only time you’ve got to be careful on lowers is if you’ve got a really deep bite. So sometimes the buccal cusp will come quite a long way down. The upper buccal cusp comes a long way down the buccal surface of the lower. So again, mental photograph, take a picture. I’ve got that.

Just place the undercut low enough, below that it’s not going to fail the occlusion. And again, technicians tell you if you’ve got enough undercut or not. And if you’re really keen and you love prosthetics, buy yourself a surveyor. They’re 80 quid on them on eBay.

[Jaz]
If you’re doing a lot of dentures, I think that’s great tax deductible investment, as I say.

[Mike]
And they last forever.

[Jaz]
It’s one of those things that thankfully do last forever in dentistry. You’ve talked about guide planes, talk about rest seats, which I absolutely love. You kind of surprised me with these viewpoints and I love them. All of everything you said, I’m definitely implementing some of that.

The fried egg analogy or the description is brilliant. Personally, when I’ve done in the past, I’ve kind of just like visualized creating a curve. I do like the fried egg. I’m going to check out your Instagram. I’ll put the little video there for people to check out as well, which is great. We’ve talked about green stick.

We talked about border moulding. Answered all of my questions. I’m so chuffed. If you talk about impression materials, we could have gone forever and ever and ever and we’re coming up to time. Before I invite you to tell us more about where we can learn more from you. I mean I’m going to put your resource of an instagram page and please more power to you. Keep sharing keep doing your thing.

We love it. I would love to promote your courses I’m going to put that in the link. Educators like you are few and far between I always want to put you easy access to all the Protruserati. But any final tips you want to give to those listening?

[Mike]
Listen to your technician first thing John Besford’s big on this. Listen to your patient. When you assess a patient, get a wish list of what the patient wants from the treatment. Just ask them what do you want and then shut up and listen and I’m lucky.

Jess my nurse is just brilliant. So I’m having a chat with a patient and Jess is writing down in bullet point what the patient wants and what they don’t want. So if they don’t want the metal based denture, you know that. If they don’t want visible clasps and you have to have them, you know that. And then you can work out whether it’s practical to do it and sometimes you just have to tone down their expectations or say, I can’t do that.

And just don’t be heroic. Herodontics are really bad news, you’ll agree. Don’t take on what you can’t do and just talk to your technician. Send your technician some photographs, clinical photographs, so they can see what the occlusion looks like. I’ve got a classic case I talk about where a patient’s massively overclosed and quite often we don’t look correcting the OVD.

We don’t, when patients are overclosed, but not enough people, students, particularly because we don’t teach them, they don’t get a Willis gauge outside. Just get a Willis on all your patients and just measure their OVD and their RVD. If you’ve got a patient looks overclosed and they’ve got too much freeway space, beautiful, you can jack them open.

And if a technician says there’s not enough room there and you say, well, they’ve only got two millimeters of freeway space, just draw a line under it and say, look, I need to refer you to some hero. Cause I can’t do this. But if you find out what they want and what they don’t want, it makes a big difference to their expectations and then they know you’re listening, which is just nice.

[Jaz]
Big fan of the lists of expectations and also a list that I encourage patients to make. Once you’ve given them their denture and they come back for their review, I say to make a list of everything that you feel like, any ulcers, any issues, basically, and I love just working through checklists by checklist.

Oh, he’s rubbing here. Oh, this is a bit rocking. And I worked through it all, but I had this wonderful experience. Once I posted my Instagram, I told this patient to make him, give him a complete denture at the upper and a partial on the lower. And I told him, make a list, any issues you have, just make a list.

And I’ll work through it. And he came back and he made a list of all the things that are wonderful about it. Not a single bad thing. And I said that day, today’s the day I should probably just retire, like leaving the high. I never expected this to happen. And like, it was the most wonderful note ever.

[Mike]
That’s magic. Can I just touch on where it’s rubbing? Nine times out of ten for partials complete, fit surface pain is caused by occlusal discrepancies. But what do most dentists do when the patient said he’s digging in down there?

[Jaz]
They ingest the acrylic, don’t they? In the fitting surface.

[Mike]
What they should do is get the articulating paper. First thing you say to a patient, it’s digging in bottom right. Okay, open your mouth, shut your eyes to the patient, close together slowly. Where does it touch first? The shut your eyes bit takes all the distractions away. I love that. Just close your eyes and do it yourself. Open your mouth, shut your eyes and close together slowly.

Now, if they’re in centric relation, you have to hold the lower denture down while they’re doing this. And just say, where does it touch first? Nine times out of ten, where they’re getting pain, they will say, oh, it’s touching there. So what you don’t get out is pressure indicator paste. You get your articulating paper out.

And when you’ve got the occlusion absolutely right, I just hate pressure indicator paste. It’s so imprecise. Light bodied . And you do this at fit by the way, not review, you’d use it every single fit appointment. Light bodied silicone, and I do this with my custom trays. Dry the tray, light bodied silicone wash check, tray extensions before you do second impressions.

And then when you do the fit, your second impressions should be good. Why should the fit surface be an issue? If you think your impressions were great, the fit surface is rarely the culprit of pain. It’s going to be the occlusion. And then I fit surface check all my fits as well. Light bodied silicone, dry the denture, seat the denture in, get them to do everything they want to do.

And you’ll see denture base poking through. That’s where you do the adjustments. I learned that from the best of the club. And the reviews have just gone through the floor. This doesn’t happen anymore. Fit surface pain generally go. And the shut eyes bit is the other thing.

[Jaz]
That’s a real gem. And that’s going to be the Protrusive Dental Pearl. And I love that. What I meant is when they, someone would typically adjust acrylic, is they’d take the denture out and adjust the fit surface, either led by a pressure Indicator. You’re totally right. Occlusion. I remember a patient in my training years who had this upper complete denture with just the most beautiful retention and stability.

And his complaint was that now and again his denture falls out. Just completely loses seal and falls out. And so it was an occlusal issue. And when I fixed the occlusion, that was it basically. So it was a premature contact or just dislodging it and that was the issue there. Mike, please tell us how, tell us about your courses. What’s the website? Where can we learn more from you?

[Mike]
Everything I post up goes through my Instagram because it drives my wife nuts because I spend forever on it. So everything I post up goes on there. I’ve got a YouTube channel, same name. You can find stuff on there. And the only course I’ve got lined up at the moment, which isn’t booked up, is going to be 22nd of November in London.

I haven’t gone live for it yet because I’m not very good at organizing in my life. You are, or you’ve got something And the Rupert courses. So if you want to come on impression club courses, there’s one tomorrow. The next one’s the 5th of February in Bath. So if you go on impression club, courses are on there and just keep tabs on my Instagram for courses. That’s the only place to put them. I haven’t got a website. So just look on there. I will announce it and I’ll do a live on it or something at some point anyway.

[Jaz]
Please don’t stop sharing. Keep it up. We love it from our community to you. Thank you so much. We could have gone on for days to talk. I really enjoyed my chat. As someone who I like dentures. I’ve been liking them more and more as I’ve been learning more about it and improving, but I really enjoyed this geeky chat. If you made it this far, it’s all the true geeks that made it here. And I want to thank you for to them.

[Mike]
Pleasure. I just love it. 51 years in dentistry now I’ve been doing and still like it, which is I consider myself really lucky.

Jaz’s Outro:
Well, there we have it guys. Thank you so much for listening all the way to the end. What did I say? I told you you’re going to love it, right? Like it’s crazy. Like we could have talked about so much more in dentures that we have to squeeze it in, in just one hour. And look how much we covered. Like it was a small amount.

Actually, if you think about it, we covered very small area of Removable Prosth, but we really went deep and I’m confident that we made things tangible. And if we did, would you please hit that subscribe button and comment below? What’s the one thing that you’re going to take away from this episode and implement?

And like with all the episodes of Protrusive or anything you learn on any course, remind you of the very first Protrusive Pearl I ever shared with you, right? Which was to know and not to do is not to know, i.e. if you now know some information, if you have just acquired some information from today, and if you don’t implement it, you may as well have never heard it in the first place.

So what will you change about your practice? How can you help Mike’s advice to benefit you with your dentures? I’ll put in the show notes below a link to Mike’s Instagram. And of course our Instagram do follow us as well, but definitely follow Mike’s. This is awesome. But I want to thank you again for listening to the end.

I’ll catch you same time, same place next week. Bye for now.

...more