The ‘Anti-Biomimetic Dentist’ – Restorative Lessons from Pasquale Venuti Part 1 – PDP152

Jaz’s Introduction:
IThe Anti Biomimetic Dentist, well, for those of you who know the Italian Stallion, Dr. Pasquale Venuti, he’s just amazing. And he’s not shy to express his views. He’s very controversial, and he won’t mind me saying this right?

And it’s not like he’s like completely in the fringe. He’s not like, ozone. He’s not removing people’s amalgams to cure them of their erectile dysfunction or whatever. Whatever, he is not fringe. He’s just on the other side of what we get taught at dental school nowadays. The adhesive approach, but what Pasquale is great at is, is pointing out the shortcomings in the modern techniques, right?

What’s wrong with fiber posts? What’s wrong with blindly following adhesive dentistry? So, what tomorrow tooth, the group, that Pasquale is part of is so good at just expressing the other voice of dentistry, take nothing at face value. So I think you’re gonna really enjoy this episode.

I’ve been sitting on this episode for a couple of years now for various reasons, mostly because the amount of interjections and the amount of additional content this episode required me to do is why it took so long. But hope you enjoy this episode and learn a lot with Pasquale Venuti. Some different views of thinking, some slightly controversial areas will be covered in this episode.

So get those onions ready because there’s gonna be lots of onion chopping during this episode. Hello, Protruserati. I’m Jaz Gulati. Welcome back to another episode of Protrusive Dental Podcast. It is your first time listening. Wow. You’ve chosen an interesting one to join us. And if you are a usual listener, like I said, man, this is the one for the onions.

We’re gonna do a two-part episode. In this episode we’re gonna cover sub gingival caries. We’re gonna cover flat onlays. Like when can you get away with it and when is it a bad idea? Is it ever a good idea? How about post crowns? We’re gonna get really deep in part two when it comes to post grounds and find out why Pasquale Venuti absolutely hates fiber posts.

And lastly, some considerations of looting cement. When is it a decent cement? When is it a looting cement? These kind of real world questions, applicable questions that need to be asked, right? So Pasquale does a fantastic job, and I’ll not waffle on any longer. Let’s do the Protrusive Dental Pearl and then hit the main episode.

Protrusive Dental Pearl
The Protrusive Dental Pearl today is inspired by a question from our splint course delegate support groups. Those of you who enroll on splint course learn more about different occlusal appliances as a GDP. These are permissive splints that don’t necessarily move the jaw in certain positions.

A bit safer for GDPs getting started into the management of bruxism with appliances, the management of some types of pain with his appliances. A little bit controversial there, but the question was, when we are dealing with a patient who absolutely loves their occlusal appliance and relying on it for many years and is doing this job, is protecting the restorations, protecting the teeth.

But now this patient needs a restoration. So let’s just take a stabilization appliance, right? Acrylic stabilization appliance, AKA, Michigan, AKA, Tanner. And now you replace a crown on a lower molar, for example. And so now your splint’s not gonna fit anymore. So the question is, what should we do?

How do we manage this scenario? Do we have to make a new appliance? Not really. You just have to gauge out the acrylic, intaglio surface best word ever in dentistry. The intaglio surface of the splint where the tooth is and then seat it back on. And so now, there’s no parts of that splint binding on that restoration from that crown anymore.

And then you assess, right? Do you need to realign it or do you not? Like if the appliance is perfect, how it is and it’s no rocking and it fills retentive and it just as it was before then I’m gonna suggest you don’t need to pull the acrylic out and start realigning that one tooth, because as soon as the patient takes off the splint and starts functioning again, the tooth’s not gonna over-erupt.

And we are keeping it simple. But if you find that by losing that one additional tooth of retention of the splint, basically, that now the splint is rocking, or the retention’s been affected, then yes, you gauge out a little bit more, make some space for a decent amount of acrylic. You put some Vaseline on the restoration, the crown, for example.

You air abrade the inside of the splint. You put some liquid monomer, acrylic monomer and then you mix the doughy acrylic. You put it inside the intaglio surface of a splint where you’ve just gauged out the old acrylic, right? So you’re essentially relining the splint. You then put it over the restoration, and then you just wait a little while, but then start inserting, removing, inserting, removing, inserting, removing.

Because if you don’t do this bit, the acrylic will lock in all the undercuts, and then you’ll have a very sad patient. So once you’ve done that, then you can just meet it up. Essentially, you’ve just picked up that tooth in acrylic so that now, It’s gonna be perfectly seated over that crown. Now it might be binding too much, a little bit too tight in the area, so it might just need a bit of relief.

But essentially it’s a good way not to have to make a brand new occlusal appliance for someone just because we’ve changed one restoration. So the ability to realign acrylic splint is a good thing, and I feel like a lot of time, general dentists are afraid to use it because we’re perhaps not so experienced with using acrylic.

Acrylics are a great thing to use, whether you use it for lucia jigs, crowns, temporary crowns, or just like I showed you, relining areas of splints. I even use it for more advanced cases, converting my B splints, for example, to have a degree of protrusion. So I’m bringing the jaw forward, right?

So I’m adding some acrylic there. Getting the patient to bite into it in a protrusive position, and then that’s like an anterior repositioning splint. So you are converting the kind of occlusal appliance you have to a different type using acrylic. So don’t be afraid to get out the acrylic, but just make sure you don’t let it set in the mouth.

You insert, you remove, you insert your remove so it doesn’t lock in. That’s the biggest mistake that you could make. Anyway, we’d like to learn more about appliances for GDPs, head to splintcourse.com. Otherwise, let’s join in the main episode with Dr. Pasquale Venuti.

Main Episode:
Pasquale Venuti, the real, the original Italian stallion. Welcome to the Protrusive Dental Podcast, my friend. How are you?

[Pasquale]
I’m so fine. Thank you for the invitation. I’m proud to join your podcast.

[Jaz]
Dude, I am so, so happy you came and accepted my invitation. You are someone I respect so much and I’ve learned so much from over the years, and I’ll describe to the Protruserati who listened my experiences with you in the past.

And when I told the Protruserati that you were coming on, so many people were really interested to hear your views which I know you’re gonna really help a lot of dentists understand your perspectives which some people with some dentists think are controversial and that’s totally cool. We love controversy on this podcast.

It’s all about learning from each other. My first experience with you was also a controversial one, Pasquale. I saw some images that you posted on social media around about 9, 10 years ago where you were treating these deep carious lesions, and then you would be destroying these papillas. And I say that as a joke, you were destroying these papillas and you were restoring these teeth beautifully, but just the fact that you’d actually blazed through the papilla for me at the time, as a young dentist, I was like, what the hell’s going on?

You are invading the biological width. I even commented, you are invading the biological width. And then you commented back saying, I did not invade the biological width, the caries did. And that was the first of our many interactions going forward. And I learned so much from you. And I saw you in Sydney.

You were with Lincoln Harrison in Sydney, then again in Stockholm when I see Michael Melkers so I’ve learned so much from you now doing your vertical course online, which I’d love to sing and praise about. But Pasquale, just for those people who don’t know who you are, tell us a little about you as a dentist, your philosophy, your views. Where does that come from?

[Pasquale]
We have the same path in dentistry. We were trained at more or less the same way, with the same university dogmas. Well, when I jumped to dental arena, I jumped with the typical overconfidence of the new graduate, a classic Dunning- Kruger effect. I felt smarter and more competent than any other dentist competitor.

And of course, more confident than my father. My father was a family doctor and he never had a formal training in dentistry. He was doing some dentistry just for his passion as family doctor.

[Jaz]
Wow.

[Pasquale]
Yeah, because at that time there were no dentist in the village. I live in a village of 8,000 souls in 80. There was a shortage of dentist in Italy. So many family doctor did some rudimental dentistry, especially caries you mean, endodontic treatments. Some mobile prosthesis ole bridge. So, my father just read three books in his life. One of N2 endodontics, a very controversial way of doing endodontics nowadays.

A book of fixed prosthodontics of the famous Bible from Herbert Shillingburg, and another book of endodontics from Wayne. They’re now are my library. So it’s not surprising. During this podcast, I’m going to show you some slides. One of the most interesting part of dentistry, you don’t need so much formal education to do good dentistry. So imagine that Greene Vardiman Black the famous GV Black, the best dentist ever. So he degree around 19 or 20 years old in Illinois. And then, he decided to do some dentist. So he went to follow a dentist of Mount Sterling in Illinois.

The. So in this office, he spent three months, he read the only book of dentistry the daughter spare owned at the time, a book of 100 pages. So GV Black was able to perform and to write and to teach the best dentistry ever, just with two months of formal education. Just one book or 100 pages.

So, let’s imagine myself, I had read coming from university, hundreds of books, thousand of literature, of dental papers. So I was very overconfident. So, the problem in coming out from university, you have not right skills and not the right mindset for facing the real dentistry.

So anyway, as soon as I jumped in the office of my father, my father left because he went to do family dentistry. So, I had a fortune to never co live with my father, so I never fight with my father. So, but anyway, I put in the basement every stuff for my father. The dentatus post dental pins. Plastic post for cast post prosthetic bars for vertical prep, amalgam.

And then I put in the new office fiber post of course, glass fiber post. At the time, I was using big shoulder bars for doing horizontal prep because I was taught at university that vertical pep was very dangerous.

[Jaz]
Hey guys, I’m gonna start interjecting now and again in this podcast to make it more tangible at various points. So for the young dentist, for the student, Pasquale just mentioned horizontal, vertical, like what does that even mean? Right? It’s a confusing term if you’ve never been exposed to it this way. Well, horizontal just means kind of like a normal crown prep that you were taught at dent school, right? You sink your bur into the tooth and now you have a margin.

Okay, you have a normal margin. This could be a chamfer, this could be a shoulder. So that is a horizontal margin. So for those of you who are watching on the app or the video, you’ll see an image of a normal cramp prep that I’ve done. But then what is different about a vertical prep is that it kind of doesn’t have a margin that is completely straight into the gingiva.

And you can kind of think of it like a knife edge. Now this might be offensive to some groups, but if you think of it as a knife edge, it gives you some degree of understanding. And there’s lots of different types of verti prep. There’s BOPT, there’s shoulders, and we’ll come onto that in little bit of a education that’ll be setting up on protrusive premium called Verti Prep for Plunkers. So that’s coming soon.

But essentially, horizontal prep is like a normal cramp prep. Your shoulder and your chamfer and your verti preps are kind of like knife edge, but that’s quite an oversimplification. But at least now you know what he meant by horizontal and vertical.

[Pasquale]
So my dentistry started with this kind of dogmas coming from my formal education. Some cognitive dissonance starts to happen in my mind after two, three years of practice because I was following up a lot of patients from my father practice with therapies done by my father with 20, 30 years follow up now.

[Jaz]
And these are root canal treatments, right? You’re talking about root canal treatments?

[Pasquale]
Yeah. They were root canal treatments. They were fillings with so-called the kite tissue underneath crowns on vertical prep with overhangs everywhere. But anyway, they were clearly successful after 20, 30 years. And my dentistry have just a track of two, three years. And my cognitive dissonance started to reach the peak.

[Jaz]
Okay, so I’m just gonna interject again about cognitive dissonance. It’s a big word. And for me it can be confusing sometimes. So I just thought I’d make it a bit more tangible, right?

What this means, like, cognitive dissonance is that uncomfortable feeling you have in yourself when your thoughts and your beliefs don’t align with your actions. So if I was to give you a dental analogy, example is that maybe you believe or maybe you’ve come to believe from the literature that you’re reading, that actually we don’t need to do total caries removal, that it’s okay to make sure we got nice clear peripheral zone.

The ADJ area must be super clean and so that we don’t exposed, we should be happy to leave some caries over the pulpal area so that we don’t expose and we’re not doing root canals where we shouldn’t be doing them right? But then this is what you believe. But when you come to actually removing the caries, you can’t stop yourself.

You can’t hold back and you end up chasing that carries pulpally and you might be exposing more often than you should. So that’s an example of cognitive dissonance made into a real world dental example.

[Pasquale]
When in 2000 I perform an endodontic treatment on a central incisors, and then I placed my fiber post, and then I did my horizontal prep, a big generous shoulder, and I did an horizontal crown on it.

After two years, in 2002, the patient came back with the crown with a post in the hand. So I was shocked because I never saw before a dentatus post or a cast post of my father in the hand of the patient. So something was not working and I didn’t know why. Anyway, after 10 minutes of shock, so I decided to go in the basement, use my first plastic post, and duralay for doing a cast post, so I redid the post doing a cast post this time I redid the crown, and yet the crown is in the mouth of the patient after 18 years now.

[Jaz]
So Pasquale just referred to using something called Duralay which is like this red colored acrylic. And what we can do with this Duralay along with a plastic post is if you put it inside the canal and then we can literally use some bits of Duralay and start building a post and core.

So you are kind of like directly chairside building a post and core as the acrylic setting. You are inserting, you’re removing, you’re inserting and removing, just like the Protrusive dental pearl I gave you earlier. And it’s a handy way of communicating to the lab exactly the shape of the canal and how you want the core to be.

Cuz then the lab sends you back a metal replica of this acrylic resin, basically this duralay acrylic resin. Now, I did this once and only once have I done this in my career and it was as a dental student, and this was with an old school tutor. But I was grateful to just gain those skills at the time. So if you’re not familiar with duralay or he didn’t really know what he meant by fabricating a metal post core using the duralay that’s what he meant.

You actually adding little bits of acrylic on to build this bigger piece of acrylic, which essentially is like a post and core in your hand. A tiny little version basically. But then that gets sent to the lab to get processed into metal. Now this is relevant because Pasquale in the rest of this episode, he’s remembering this time where he was challenging what he was taught eg the use of fiber posts and the use of heavy preps, right?

Which is completely the opposite what he does now, by the time he had this doubt, he thought that he knew it all after dental school, but he’s finding that his results weren’t as good as his fathers who was using more traditional techniques. What Pasquale now goes on to talk about is sub gingival caries and removing the gingiva to allow you to reach the caries, cuz sometimes the gingiva’s in the way and you can’t actually seat your matrix.

But what he believes in is removing that inflamed gingiva, which is really crazy when you first get exposed to this. It’s like, whoa, how does this even make sense? But I’ve been doing this for years. And you know what? These papillae do grow back and it’s an absolute game changer for me in my restorative dentistry. And some groups, people do get offended by these techniques, but I think they’ve been absolutely brilliant for my restorative dentistry. So he’ll now talk about that.

[Pasquale]
So what I was seeing was in strident contrast with what was published at the Dental literature my patients were not a patient of dental literature.

My patients were an average with low income, with very better oral hygiene, and most of the decay were underneath the level of soft tissue. That’s why my first need is to become free of gingiva when doing some fillings. That’s why I start to cut soft tissue. So I know after cutting hundreds of papilla, so I start to see back the papilla in a few weeks.

So I realized that it was not a big problem. The big problem was not cutting the papilla because at the beginning, for example, I did not cut the papilla, papilla was like a religion to me. So what happened then? I placed my matrix because I had the impediment of the papilla. My wooden wedge was too occlusal and crushed the matrix inside the cavity.

So my feeling was very bad with a very strange profile. But if you got the papilla, you are able to do a perfect proximal profile and papilla will grow up again, a guess.

[Jaz]
And this is so simple, Pasquale, cuz this is why I learned from you initially, because the traditional ways that I was taught to manage that would be, oh, this patient needs crown lengthening.

That’s what I was taught. And when I saw you doing such a simple thing like that, and then now having done it hundreds of times, myself, seeing the Pilla come back, seeing year on year, how good the tissues look when they have been educated properly how to clean it. And the fact that I was able to now restore these teeth without surgery and everything’s fine is just mind blowing. Why the only other option was suggested to be crown lengthening?

[Pasquale]
Yeah, I started with crown lengthening. I mean we started with the same path. So, my patient had very bad oral hygiene. So after crowd lengthening, they ended up with a big black triangle. They didn’t clean. So the situation is even worse for them.

So, and after some years I get also new decay on the root because with crown lengthening you expose the roots, so the situation is worse and worse and worse. So crowning is a viable treatment in a patient with perfect oral hygiene. But honestly, in my humble opinion, there is no need of surgical crown lengthening in restorative dentistry.

For aesthetic reason in anterior area for increasing the hate of the grounds. If you need federal, you can do auto extrusion, but if you don’t need federal effect, it’s not a problem because you cannot impinge in biology width because if caries is down there, it means that the biology width is reshaping underneath the decay.

So you have not a possibility to impinge it. So it’s fake problem in my opinion. I mean, 20 years ago there was a problem, how to get a isolation in very deep caries lesions because rubber dam sometimes is not enough. But with Teflon nowadays, we can easily manage a very deep margin. That’s why you need such a crown lengthening just if you’re not able to isolate the tooth.

But nowadays, thanks to Teflon, we have almost infinite possibilities to reach every margin, even underneath the level of the bone.

[Jaz]
And for those listening right now, if you wanna see examples of these teeth being treated, Pasquale is so good at posting so many cases and also so many follow ups, nine years later, 12 years later, three years later, all over.

So join the Tomorrow Tooth group where Pasquale posts a lot of cases, and I encourage everyone to do that. And I love already how we are getting into the clinical details and stuff, but like, there’s so many things I could ask you and share from the lessons that you’ve taught me to the Protruserati, but we’re gonna focus on a few different tangents we’re gonna go on now.

Firstly, I just wanna mention for the purpose of the podcast, that there is some tension, there is some friction. There is, I don’t wanna say war. War is a harsh term. There is some friction, let’s call it, between the biomimetic dental group and tomorrow tooth principles and that kind of stuff. And I just wanna say that, look today it’s about listening to your views and your experiences.

And then I will also have some biomimetic group on and they will share their experiences. And it’s all about learning from each other and sharing our views. We’re not gonna come at it as an attack. Let’s collaborate, let’s listen to each other’s views. That’s very much the angle this podcast is coming from.

So the theme of what we’re gonna cover in this podcast is we’re gonna talk about traditional retention, resistance form versus adhesive versus completely flat adhesive, and where you think on that. Then we’ll talk about the limits of adhesive, and I know you have some really amazing cases of how you manage these very deep caries lesions, yet still doing adhesive dentistry.

We’re gonna talk about the concept of post crowns and where they lie. And then also go deeper into fiber post versus cast metal coast, cast metal post, which is something that a lot of the listeners have requested for almost a year now. Your views on the C- factor when it comes to indirect restorations.

And finally at the end we’ll talk a little bit about the use, this surge in use in fibers. And I don’t mean fiber posts, I actually mean fibers in composite. So, if you wanna listen to that, you have to wait all the way to the end. So, first question, Pasquale is, and just from my experience, there’s traditional dentistry that the horizontal margins, whatnot.

And then of course, nowadays replacing more and more vertical for those who are enlightened and stuff. And most of my crowns where I don’t have enamel all day round, I will be doing vertical crowns. That’s my philosophy. For me to go adhesive, I want at least 90% enamel for me. And I don’t want to overzealously use deep margin elevation, especially in someone who has poor oral hygiene.

That’s my view at the moment. And that’s very much I think, echoes what you’ve taught me as well. And correct me if I’m wrong later, but I see more and more on social media, the use of a very flat platform for a adhesive onlay, i.e. a tabletop onlay. Whereas whenever I prepare for an onlay, I still like to follow the angles of the tooth and get some form of resistance form.

Even a small degree is better than going completely flat, but I see more and more flatter and flatter adhesive indirect restorations. So what do you think? What is the limit in terms of how flat do we go? Because I saw you post a case recently where you were saying, you know what? You’ve lost faith in these flat preparations and you need to still build in some resistance form. Can you enlighten us on that?

[Pasquale]
Yeah. I’ve been practicing dentistry since 20 years now and many of the people that collaborate with tomorrow two, like Roberto Magallanes Ramos John Khademi Dev Clark. So they were practiced dentistry then since fourth years. So we tried during our path, both strategies. The so-called classic strategies with retention and resistance form and the new way of doing adhesion on unretentive and unresistive preparation, the prep, there are completely flat.

So, those preps are proposed by people that self proclaim ourself, biomimetic dentist. I don’t know, what does it mean. Anyway, this kind of dentistry, the flat dentistry, they unretentive and unresistive dentistry has two main problems in my opinion. The first problem is operative problem, so trying and only with no form of resistance is an nightmare because it slips everywhere.

For example, how you check the contact areas on a flat onlay. So we have not a possibility. It’s a circus. The other problem you have not a univocal position of the onlay. So what happens that areas can move and slip a bit or shift eventually the onlay from the decided position.

So, but there is another biggest problem there is not operative it’s a rational problem because we have no literature about the longevity of this kind of unretentive and unresistive. Always. We have just some case. Some follow up study at one, two years old. You mean we do dentistry for serving the patient for 10, 20, 30 years.

But with this background of just one, two years follow up, I would not be so confident to serve my patient with this kind of preps. Anyway, I had the possibility to experiment on my patient this kind of dentistry since 2013. And the rate of failure on my experience at seven years is almost 40% of the bonding.

[Jaz]
I just wanna say Pasquale, for those listening who don’t know who you are, like I can guarantee you guys it is nothing to do with Pasquale’s hands not being good enough for this type dentistry. Like, if you see his adhesive dentistry, his isolation’s always meticulous. Pasquale can do any procedure he wants in my mouth.

I trust him. So it’s not to say that, Pasquale is not bonding correctly, not isolating correctly, not using air abrasion, et cetera, et cetera. He’s doing the beautiful dentistry. So this, it speaks volumes when Pasquale is saying that something, at seven years, he’s noticed a 40% failure rate.

[Pasquale]
I mean, I will show you later in the presentation some cases, okay? Some tough cases, okay? Tougher than every case has been published in the dental literature so I tried this kind of prep in many ways. But the biggest problem, especially for a young dentist is how to locate the onlay because we have no index. When you have a flat policy, you have no index. And restorative dentistry in indirect restorative dentist index is paramount. Because you have to have a unical position of your restoration.

[Jaz]
So what does Pasquale mean by indexing? Let’s make it tangible. Sometimes to understand something, you must understand what it isn’t. So if you have a flat onlay prep, right? And you imagine trying to seat an onlay on this flat prep, and it’s kind of like moving around.

Like you can twist it, you can seat it many different ways, and maybe it’s slipping. A bit, right? Maybe you’ve experienced this firsthand with your fingers. Now the opposite of that would be a crown preparation with lots of slots and grooves, and it fits in really snugly in that one position.

That’s a highly indexed restoration. So what Pasquale means that we should move away from completely flat preps and have a degree of anatomy inside the in taglio surface of the onlay, for example, that’s gonna seat in and not be slipping. The contacts won’t be slipping. The onlays not slipping off.

And this is called indexing. Not only is it but good for your technician, it makes it easier for a technician to make you a good restoration. It makes it easier for you at the time of your cementation or your bonding procedure to make sure that you get that one path of insertion. So indexing is a good thing to have.

[Pasquale]
And with flat onlays you have it now. So what we did, at some point, we start to do some hole into the center in order to locate, because it’s not all your problem, it’s all the problem of the technician that cannot have a exact location. So sometimes if the hole is not so deep, the former resistance is not enough. But there are a lot of problems, eh?

I will show you better. One of the biggest misunderstanding in the dentistry nowadays is about C- factor, because the people that proclaim that flat onlay has a very low C- factor, okay, are completely wrong because they do not understand the basis of C factor. Because if they studied the work of Carol Davidson, the inventor of C factor, C factor is called in this way because the name of Carol Davidson.

So they will see that in 1985, Carl Davidson studies the flat onlays. Flat onlays have infinite C factor. C factor is extremely high because you have one surface, there is the tooth surface and the onlay. So, and the cement has to compete with two surfaces opposing each other during shrinking. So you will end up with a lot of crack inside the cement.

So if you have no form of resistance, what happens that under the true load, especially the parafunction, the crack will start to move and to continue inside the mass of the cement you have the bonding at some point, so it works very fine if you have a patient with no parafunction. But if you have a patient with parafunction, you will end up with the only hand in a few years.

[Jaz]
As you taught me Pasquale it’s a good way to say it is the biomechanical risk of a patient. And there’s a difference as you taught me many years ago about these. A patient who has low biomechanical demands and high biomechanical demands, and it’s important to appreciate who you’re dealing with.

So maybe what you’re suggesting is maybe those 40% of cases where you found that these flat preparations, would you say that a lot of those were in patients with high biomechanical needs?

[Pasquale]
Of course. Of course. Most of the patients, this is for every therapy in dentistry so a filling lasts 30 years in a simple patient, in a patient with lower biomechanical demand.

That’s why sometimes you see gold filling, lasting 30 years, but if you check those mouths, you will see that in that mouth there is no wear. It’s not about gold, it’s about the mouth because all also composite filling can last 30, 40 years.

[Jaz]
Wow. Even amalgams do 40, 50 years and we see all the time and everyone says amalgams causes cracks and stuff. I’ve got plenty of patients with 30 years amalgams not a single crack.

[Pasquale]
How many cracks you see in a patient with virgin teeth? A lot?

[Jaz]
Mm-hmm.

[Pasquale]
So you mean the crack is about the force, the vectors, the muzzle vectors. It’s not about what you pull inside a cavity. Anyway, I will show you many cases about cracks just for giving you a better idea.

[Jaz]
Brilliant. We’ve talked a little bit about the importance of having a degree of resistance, especially in this patients with a higher biomechanical demand. What is the limits of a decent dentistry? Because I’ve seen you do some really tough cases and go on really over and beyond with your skills to try and isolate and try and to achieve all the adhesive principles. But where do we draw the line? Where is it for you personally, Pasquale, that you say, okay, this will be adhesive, this will be non-adhesive. Where is the limit?

[Pasquale]
A couple of years ago, I had a discussion with my friend Marlene Payman from Luve University because I challenged her to define what does it mean, adhesion? So, for example, if I ask you is an adhesive or not? In your opinion?

[Jaz]
I would say that GIC would come into the category of an adhesive cement.

[Pasquale]
So how do you cut the threshold between an adhesive cement and nonadhesive cement?

[Jaz]
Well, actually now I’m thinking about it for me. Now you say adhesive should have some sort of degree of resin. So if it’s glass or iron cement, that’s a chemical setting, whereas a resin modified glass man would have at least common. So actually now I’m gonna revise my answer and say if I’m using something like a Fuji plus, which is a GIC ba base cement, that would be for me. I use it for my non-adhesive crowns for like my verti preps for example, vertical crowns I would use Fuji Plus or something. So I would say no, it’s not adhesive.

[Pasquale]
I mean, when you talk about adhesion from the chemical point of view, you have adhesion when you have some chemical bonding between two structures, okay? Instead we are using the word adhesion for defining some cement they have no chemical bonding, but micro mechanical interlocking.

[Jaz]
Yes. Yes.

[Pasquale]
Because the hybrid layer is just a mechanical interlocking. So the only cement that we can use adhesively in then is glass ionomer not the resin cements anyway.

We tend to classify a cement been adhesive. Just if you get 20 giga pascal in adhesion. For example, if you are under 20 giga pascal, you tend to see the, to say that it is not adhesive cement anyway. The problem is that how long is the micro mechanical bonding, how longevous it is, what can damage the micro mechanical interface?

So that’s the question. You can have some giga pascal of adhesion at the beginning. It is longevous or not so, and what we have found over time that this bonding is very longevous on the enamel, but it’s not so longevous onto the dentine. Because, the problem, the biggest problem with dentine that we have no dentine.

We have what I call the 50 shades of yellow just for no, when a dentine is decay is attacked by dec. It change structures, and when you bond that dentine, it’s not easy to have longevity’s bond, in my opinion. This is my experience. After 10 years, if you start to remove a filling done well, you have a very trouble to remove from the enamel.

But then after you have removed the addition onto the enamel, you can remove the filling with an excavator because the adhesion to the end is completely lost. You can do an experiment. Everybody should do this experiment. You have a deep filling, you have a deep decay. You have to do a deep marginal elevation of this dentine. If you just do a bonding of two millimeter of denting of this deep margin, okay? After the light curing, you can remove within excavator that little piece of composite. That’s why when you do a deep marginal elevation, I highly suggest to create some mechanical interlocking with the enamel.

So you have to extend the platform because if the deep marginal elevation is very minimal, it’ll detach easily because that then is not prone to the bonding procedure.

[Jaz]
I mean that makes sense, Pasquale in terms of how deep you are and you’re purely on dentine, but to extend it onto enamel, you mean we should also go a bit more buccal and a bit more lingual.

[Pasquale]
Buccally-

[Jaz]
So that it’s fine. Understood.

[Pasquale]
Yeah. You have to extend the platform at least three, four millimeter inside a tooth, because if you limit yourself a deep little margin, the bonding is quite poor. It’s almost zero, so, but why enamel? The enamel is quite stable. It’s a rock, so it doesn’t change. It’s the same from the first day of the patient to the last day of the patient.

Dentine change over time, change color, change structure. So enamel offer another advantage. It make the tooth very stiff. If you have a lot of enamel, so the tooth cannot bend easily, but if you have lost most of enamel, the residual dentine under the chewing stresses can bend if it bends, the mechanical interlocking with composite will us teach very easily.

So that’s why if you have a lot of enamel go with adhesion, even with the flat surface. But if you have not so much enamel, honestly, it’s better to project and design is something that is re resistive and resistant in my opinion.

[Jaz]
Brilliant. So, Pasquale, just to wrap that up, and I told you one of my guidelines for adhesive versus non-adhesive is at least 90% enamel.

Would you like to offer some sort of mathematical or rigid guidelines in terms of that, if that helps the young dentists understand about when to go adhesive and when to go non-adhesive, mechanical.

[Pasquale]
So many people will, it’s not about how many enamel you have all around, because some teeth have a lot of enamel around about the surface, but the thickness of enamel is very minimal because, for example, is an erosive patient.

So erosive patient is not easy to treat because you have enamel at 360 degree, okay? But you have adjusted 0 3 0 4 millimeter of enamel. And 0 3 0 4 millimeters is not enough for me adhesion, you need enamel, almost a 360 degree. You can accept 250 degrees of enamel around and at least a thickness of enamel of 1.5 millimeters.

If I have less than 1.5 in thickness, I will not do any adhesion. Anyway I will present later in the presentation some cases that are very paradigmatic. What happens when you do a filling in an erosive patients, so you have enamel, but you have a very teen enamel, and you will see what happens to the fillings in a few months.

Jaz’s Outro:
Amazing. We’d love to see that. Yeah. Brilliant. So then, and the next thing we wanna talk about Pasquale is the whole concept of no post, no crown. So this concept of we want to avoid placing posts as much as possible, and we want to avoid doing crowns and instead do onlays to maintain the gingival third of tooth structure where which is responsible for the strength of the tooth.

Now, my own personal views on post is that I haven’t placed a post for like, maybe two years now, because for me, if I have enough feal, then I think almost I don’t need a post. I can just rely on my composite and the crown will be engaged in a feal. If I don’t have any feal then I’m thinking, why are we even using a post here?

So for me that tooth is for the bin or needs some crown lengthening or something like that. Or even if I can’t get that fair ferrule from a vertical preparation for example, we can gives you a little bit more ferrule to play with. For me, that tooth is unrestorable. So I’d love to hear your views on this mantra of no post, no crown and find out how much you in your daily dentistry are using posts at the moment. Well, there we have it guys. I’m sorry I left you on a bit of a cliffhanger there, but we’re gonna cover the big bad topic of post next time. We covered a lot of ground, we covered a lot of breadth, but in the next episode we go a little bit deeper into some of these areas, especially when it comes to posts and why in this world where everyone seems to be anti post, he is pro post.

And even then it’s like a class post that he favors. And we’ll find out a bit more about his philosophies in restorative dentistry. If you’d like to gain some CPD, just head over to the app protrusive.app or on your device like Android, iOS, you can actually download the native app. And just by answering a few questions, you get some CPD for this episode.

There’s also monthly premium content that I add all the time. But I do wanna thank you for listening all the way to the end of this episode, and I hope you look forward to part two with Dr. Pasquale Venuti, same time, same place next week. See you there.