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Welcome to The Ruddle Show. I’m Lisette and this is my dad, Cliff Ruddle.

How are you doing today?

Pretty good; how about you?

Never been better.

Okay, well this is our first show of Season 11, and it’s also the first show of the new year. So I think it’s pretty safe to say that probably the most common New Year’s Resolution that people have is some version of losing weight and getting in shape. But I think by the time this show airs, pretty much the gyms will be deserted. So what are some other inspiring goals to have for 2024? Well maybe you might want to consider investing in your future. Now I know that you and Mom have some money invested with an investment firm, as well Lori, my sister and the show producer. And you’ve been trying to get me for some time now to do some investing. And I do have a savings account, but my money just sits there and it doesn’t really grow. So how long have you been investing?

Well, before I answer that, I would like to get back to that pile of money you have in savings. We need to get that money working. You know, I think you guys should know, your staff in most cases if you’re investing in yourself, Doctor, then you invest proportionally in your staff. So you’ve actually been in our 401K at Advanced Endodontics.

That’s right; I do have that.

Yeah. And you’ve been there for like – I was looking it up just to make sure – almost 20 years next year.

That’s how aware I am of it.

So she has some investments, and we’ll talk about the power of folded paper soon. But anyway yeah, you do have that. But I’m looking more at – you have quite a chunk of savings, and I know like your mother, you want to have a little cash on hand for a rainy-day fund, and that’s important. But at some point, I think it’s important for all of us to figure out what would represent the rainy-day fund – what level would it need to be at – and then the rest could go and work for you. So my goal with Lise is to take a fairly large sum of cash and have her take some aside for discretionary rainy-day funds, and then invest the others. Because back to your original question -

Yeah, how long have you been investing?

I’ve been investing very late – I started very late. And I used all the excuses that I’ve learned; I’ve learned abundantly clear that they were excuses. Oh, I had tremendous University of Pacific debt; it was the second most expensive dental school in North America when I went through. I borrowed my way through it.

Then I went to Harvard, and that was post grad, and I borrowed my way through Harvard. And then when I came to Santa Barbara, oh, guess what? I borrowed to join the group. I was in a big building in a medical complex, and that cost money and I forgot it was just a shell of a space and so I had to build it out for dentistry. So those early years, I was doing massive debt reduction. But as I’ve gotten older and wiser, you always invest in you before you pay down your first bill; you invest in your future.

So that’s just a short comment about that. I wanted to maybe do something funny for the audience, but it’s the power of money. And you’ve got to realize – well first, I’m going to have you tell the penny story and then I’ll tell my story.

Okay. Well you asked – he asked me if I would rather have a million dollars, or be given a penny and then have it doubled every day for a month.

For 30 days.

For 30 days, what would I choose. Well I thought well probably the answer – the correct answer is the penny. But I’m going to choose the million dollars. But I was thinking to myself; no it’s not right. You get more if you do the penny doubled every day. And so then I actually just before the show, I wrote it all out and I did the math and stuff; and I realized that by day 30 you’re at $5 million- something.

And that’s the thing Albert Einstein, with all his genius; he always said – with all the things he was thinking, all the theory in his mind, he said the thing that was the most hard to get his arms around was compounded interest. So if you get 10% - and sometimes we don’t based on the economy – but if you can get a 10% return on your money, money doubles every 7.2 years, and that’s what you started to find out.

And another way is the old paper fold. Maybe the audience will get this. But did you know that if you take a regular old sheet of paper – it doesn’t have to have the three-hole punched, that just went in my show binder – but you can measure the thickness of this. There’s a measurement. And if you double – if you fold the paper once, twice, three times, four times, whoa – five times, six times – you can begin to see that you’re getting some thickness going. And like she found out; it really gets interesting up the line because the folds are staggering. So if you were to fold this paper 45 times – and it’s only possible to fold it about 5-7 times, even if it’s toilet paper, really thin – it just gets staggeringly difficult because of the mass. But if you folded a paper 45 times, it would go to the moon from the earth; earth to moon. And if you want to get those last folds – do you know how much further the sun is out than the moon? If you fold it five or six more times, you’re to the sun. And the sun is only 100 million kilometers from here. So get investing!

Okay, well I do understand. On an intellectual level I understand the compounding effect. And I also realize that there’s different levels of risk for investment, so you don’t have to be in a high-risk area; you can choose low risk investments. And I think as you get older, you would choose lower risk so you don’t lose everything if something should happen.

Right. I grabbed your kid many years ago, and I marched him down to Mission Wealth here in Santa Barbara, because we had worked with this financial planner for many years. Even when she wasn’t there; she was at another firm. Anyway, we followed her. I wanted Isaac to go down there and just meet her, because the importance is starting early.

So back to your original question of when I started. I started too late. But I did start, and I didn’t start until about 20 years after I got out of grad school. So 20 years is a lot of folds; a lot of mistakes were made by Ruddle. But you want to get going early. And the reason you want to get going early is you want to invest in yourself; how about that? And there’s inflation; it just kills us. I mean inflation since Covid and all the big payouts by the government; flooding the economy with money so prices have been going up. So how you can beat that a lot of times is by investing. So while you’re sleeping, when it’s the weekend, when you’re sailing out on the lake or the ocean; the money is working, it’s always working. So you do it to invest in yourself, you do it to beat inflation, you beat it so you have a retirement plan – wouldn’t that be nice?

Yeah, and you mentioned Isaac. He’s 24 and he’s invested in the same firm as you guys as well. And he’s been actually interested in stocks since he was a teenager, and Mom actually helped him get started. Like just for fun, just acquired a few shares of stock here and there, just having fun with it; kind of like responsible gambling.

So maybe this will be the year that I start investing. Apparently Mom is going to help me get started, so I strongly encourage all of you out there to ask your moms for help too. And I guess there’s some quote about investing; something like the biggest risk of all is not taking one. Something along those lines. So I guess maybe we all want to consider investing in our own future this year.

Well, we have a good show for today, huh?

Yeah, I think we have a great show. And with the investments, you’ll be able to relax and enjoy the show because the money will be working.

Okay, let’s get going now on Season 11, the first show. And Season 11 we’re calling “Road to 100,” because by the end of this season we’ll be at show 100.

And that’ll be pretty special, right?

Yes.

All right. Well today we wanted to talk about a new textbook that is coming out this year, and for which you just finished writing a forward.

Correct.

And the textbook is called Tooth or Implant: The Recovery or Replacement of the Severely Compromised Natural Tooth. And the principle authors are all Italian, and I will try my best to say their names. Professors Pio Bertani, Paulo Generali, Fabio Gorni and Tiziano Testori, as well as the editor who is Massimo Gagliani. And there are also several other contributors, all of whom are recognized experts in this subject matter and all who happen to be Italian. So how is it that you, a lowly American, was asked by this Italian group to write a forward for their textbook?

Well Fabio explained to me; I wasn’t quite good enough to be in the book, but he thought I was coming along and I was making enough progress that I could probably write the forward. So that’s how that worked.

Okay.

Well, how do I know Fabio? First of all, I don’t really know many of the other authors; I’ve never really met a lot of them. Some of them I have. But Fabio and I go way back and that’s probably the connection. He came over in the early 90s and he came to Santa Barbara with a group of Italians and they were all Italians. And this is very special if you teach, because there was a lot of singing and there were a lot of things going on that I wouldn’t really know about because they had a lot of their own – I don’t want to say cliques, but their ways of saying things, talking, and the singing was always in Italian.

So that week-long course we learned a lot. It was a lot of fun; very exciting. And then they went home, and wouldn’t you know, I noticed the next year he was signed up for another week-long, and it was a different group of Italians, but nonetheless Fabio was in that group. And I was pretty excited about it because he graduated from Milano, the University of Milano, and I think it was 1984, which I’ll talk about a little later in this show.

Important year.

It was an important year, think Olympics. Anyway, he was born as an Olympian in endodontics.

So anyway, he came back that second year and we had another great week: Clean•Shape•Pack, Nonsurgical Retreatment, Microsurgery, all crammed into those days. And it was a beautiful period. He was so enamored by learning and everything he was getting from all the people and the courses, and he loved Santa Barbara, so him and his wife at that time, Stefania, came back and spent one month here. So I had the best time with Fabio. We played tennis and we did all these things; went to the beach, went to the wine country, it was a great time, had barbeques. And so I really got to bond with him.

So out of that, he wanted me to come to Milano and he wanted me to make – we called it a set of tapes on Shape•Clean•Pack, and Herb Schilder wrote the Forward.

Oh, these are just tapes; they’re old.

Yeah, I won’t even break it open; they’re tapes, VHS. Anyway, Herb Schilder did, in fact, speak on the opening. It was very exciting for both of us at that time. So that’s a little bit about how I know Fabio.

Well I do remember Fabio very well when they came to Santa Barbara, and his wife Stefania. I actually just remember thinking that they were both just really beautiful people.

You know, one thing I will say. When I did this, it was two weeks. And I mean we were at the studio at 7:00 in the morning – and that’s pretty early for Italians, as I learned – and then we were there till late at night; maybe 9:00. But anyway, while we were there, he insisted that I stay in his house, even though Stefania was very, very pregnant. And I didn’t want to be in the way because she was going to deliver any day. And so Stefania put her arm around me and she said see; don’t worry. If we have to go, I knock on your door, and if you hear the three knocks you know I’m off to the hospital.

Well geez, about four nights later [knock, knock, knock]. And I said good luck! And anyway, Fabio picked me up at 7:00 later in the day to go to shoot the shows, and he said I have Jean Marco; a little baby, a little bambino! So that was pretty exciting.

Okay. Well back to the textbook. It’s about 250 pages, and it’s divided into four main sections. So what are the four main sections?

Okay, well the first section as you would expect would be diagnostics and interdisciplinary treatment planning. And that’s really important in these more sophisticated cases. There was a lot of emphasis on evidence based, so everything they’re talking about there is some evidence behind it to support their clinical activities. That was the first section.

So pretty much deciding if you’re going to do a tooth or implant.

And as you pointed out, it was a lot of the critical thinking that I thought made those first four chapters so remarkable. Because a lot of times you get a book and you do step 1, step 2; how to do something; how to do something else. But they gave the thinking behind why they made the decisions to do what they chose to do. So that was really cool.

That’s helpful.

Ours truly, fabulous Fabio did the second major section and that was all on endodontics. Because remember, it’s “or.” There was an “or” in there. Is it the tooth or is it the implant? And so Fabio did a remarkable job talking about wild, difficult anatomy, with treatment complexities from previous failed endodontics. So it was a great combination of resurrecting previously treated teeth that were failing, with great anatomical variation – very exciting. Broken instruments, blocked canals, ledges, perforations; he was showing all this. So that was pretty interesting.

The third grouping – about four more chapters – were on atraumatic extraction, and now we’re moving towards the implant. And so it was immediate implants, immediate loading. So that was pretty neat. And then handling soft and hard tissue defects. The fourth chapter was over my head. Not chapter; the fourth section. Another four chapters.

It talked about PET – I had to look it up – it’s Partial Extraction Therapy. I’ll have to admit, I hadn’t really heard of that. What they do is they section a tooth like this – if you could flip this tooth around - and leave the natural root right here so you still get sharpy fibers, and you get ingrowth into the root surface and you have a PDL. That saves the bone. And then they section the tooth mesial/distal, and take out the lingual part of the tooth and the gutta-percha if it’s been previously treated. And then they put the implant in parallel to that, so they hold bone. It was a very sophisticated technique; it’s called socket shield therapy. So if you want to learn about some of this stuff, it’s never too late. You can always become what you always wanted to be, and that book promises to be not just another textbook. It’s pretty exciting, because there’s very sophisticated interdisciplinary stuff. And that team of people, they’re good; very, very good.

Yeah. I actually looked through an electronic version of the textbook, and I have to say I was really struck by it. I mean the photographs are amazing, and just all of the documentation looks outstanding. So it’s a really nice-looking book.

I have a question, and maybe some of our viewers do as well. I’m just wondering why you would publish a textbook nowadays. Because with the internet, it seems like pretty much everything you need to know is available online; and if something changes it can be updated instantaneously pretty much. So I’m just wondering what are the benefits of actually publishing a textbook today? Are people actually reading textbooks?

According to an Italian study – nothing to do with the Italian dentistos – but there was an Italian study in 2014, and it showed that people that read books absorb more data. They not only absorb it, they retain it more than if you were to read it on a machine like an iPad, an e-book, or even your phone. So absorption of material and retention, I would think, is critical.

I’ve skipped some of the stuff you said I could talk about; I’ll let you talk about the stuff a little bit later. But I just said easy and convenient and flexible. I can throw it in my car, I can go to the beach, I can put it in a backpack and to climb one of these hills in the back country, sit down under a big old oak tree and pull out my faithful Fabio Gorni, et al, book. I can just open it up, it’s right there, and I can just pack it back in.

So I think the convenience, I really like that. And you know, I mark stuff up. So it’s hard – maybe there’s a feature on a phone – but when I’m reading a book, especially if it’s technical, I’ll have a yellow pen right here and I’ll just mark it up. So I like that.

Yeah. I mean there are some other things. Apparently, reading a book before bed helps you sleep better than if you are scrolling through your phone. Because the phone emits this blue light that can mess up your circadian cycles and your melatonin levels – meaning basically that you sleep more restlessly and you wake up tired.

There’s probably other distractions too, right?

Yeah. People tend to be more distracted when they’re looking on their phone – when they’re reading on their phone than when they’re reading a book. A lot of that is because say you’re reading something and then alerts come in; that could happen. But also you might read something that makes you think of something else, and you’re like I can just Google this really quickly. And then all of a sudden you’re like maybe I’ll just check my social media really quick as well. So it’s definitely less distracting to read a textbook.

And then apparently also, people who have home libraries tend to have a higher academic achievement than people who don’t have books in their home.

Interesting.

So according to that idea, mom and I are geniuses; we have so many books.

You guys have the books, don’t you?

All right. So there’s definitely some benefits for a reader to read an actual printed version textbook. But there’s also a big benefit for authors to publish a hard copy book; correct?

Well there are. You would expect this, but – I don’t know about the word “authority,” but when you write a book, even if it’s bullshit, it could be you’re an authority now. But this book would make them authorities, and if you didn’t already know it, you would know it if you saw the book.

Well what about a book? A book can get to people that will never see you. I’ve said on this format many times that by the end of 2019, Phyllis and I had done over 3.2 million miles – air related miles to lecturing. That’s a lot. Did I see everybody? Not even close. So if you have a book, you can get it out to schools; sometimes the school will even take a book on and it becomes the official book for an advanced class. So you can reach a lot of people with your book because you’re the authority figure.

And then I think you spread your ideas. Because again, if you’re just watching this show and this is all you see, you’re getting some ideas and things. But if you didn’t watch this show, you’re not getting those ideas and that input. So I think it gives you more leverage in the marketplace, and I think – I guess I could write down the word “legacy.”

It’s an important word that we’re going to be coming back to many times this season. It’s kind of our theme for the season. So I’m just saying that right now; “legacy,” remember that word.

Yeah, and you have talked to me quite a bit about that in many different contexts. But when you write a book, you kind of – suddenly he’s a published author; he’s an authority; he’s getting his legacy going. So those are reasons, I think, that book writing and publishing is still very, very important.

Well it’s true. Because it is kind of like – okay, say he just posted something to his website. We might not be talking about it here on this show. But because it’s an effort that’s actually a textbook that’s been published, we’re talking about it. So it kind of puts you out there a little more than if you just post something online.

So yeah, people are starting to see now that books are still really relevant in our society today. And apparently most people do prefer to read an actual printed textbook, or book; they prefer to actually read a hard copy version. And that goes for even millennials, believe it or not; except for maybe not my kids. But yeah, millennials even prefer to read an actual book.

So do you have anything else that you want to add?

Well because I’ve done this for Fabio, I would like him to come back to Tiziano Testori; and we’d like to drive about one hour north of Milano and go to Lake Como. And Tiziano, do you remember? You put my sorry ass on the boat with about 12 other dentists, and we plied through those waters and we went to Bellagio. That’s where the three – it’s like a Y. And at the Y, at the convergence of the Y is this fabulous restaurant and the boats pull in there. And the mountains are granite faced and they come right up out of that lake, 2000 feet, snow-capped in the winter, beautiful summer Alpine. So Fabio, Lise and I are ready to go to Lake Como.

All right, well thank you for your contribution to the textbook and for giving this information today on the show. That was a good segment. Thanks.

Yeah. And the last thing I did say in the forward, and I’ll just leave it – we’ll say it again. Whatever you can do or dream you can, begin it. Because boldness has genius, magic and power within it, and that book will give you the juice to go be more than you are.

Yeah. It may be a book you want to add to your dental library.

Okay. Today I’d like to return to talk to you about straightline access, but I want to delve a little bit deeper. Just for your information, I’m really glad you’re back, I’m really excited about this season and we have a lot of things to go into. But just to get back to the topic and save all my enthusiasm for later. I’ve talked about straightline access many, many times in many places over many, many years -- decades. But I wanted to delve deeper into it, because I always have been talking about straightline access in the context of endodontics. In other words, finding the orifices, inspecting the axial walls for fractures that might fade out and play short of the floor, or maybe they overtly go to the floor and across the floor. So I’ve always said, get the tooth opened up so we can see it. And appropriate access. I’ve always talked about access in terms of glide path management, manual or mechanical. And of course, if you have a great access, it helps you with your shaping. And even in the advent of NiTi files that are really flexible, at D12, 13, 14 and 15, relatively speaking, as compared to their tips, D1,2,3,4; people are saying well, we have such great flexibility now, we don’t even have to worry about triangles events.

So I want to talk about all this. And of course, if you’re going to get your armamentarium in for disinfection; everybody’s going to disinfect better through a good, complete access. And of course, if we’re talking about filling root canal systems, regardless of the method, a great access is like a rising tide that raises all endodontic ships.

Okay, so that’s the context that you’ve heard me really pound away on access. I’m going to review that very quickly, because it’s been talked about many times in many places over many decades, as I just said. But I’m going to do into a little different spin on it from the restorative standpoint, because I hear so much noise; oh, you don’t have to have straightline access. Well is that true or is it just somebody made it up and because they said it 7 times, posted it on a website somewhere, ran a flag up so you found the website, and suddenly they’re an authority and the whole world goes oh! Hmm. I wonder. Do we really need straightline access?

So as you begin to look at furcated teeth, and you being to think about root canal systems and pulpal space and anatomy, we always come back and we look at the triangles. So we’ve talked about that. You can see these triangles in here. We’ve talked about the orifice directed access, which you don’t see today, but the orifice directed access was punching little slots up in here to find an MB or an ML, or a little slot down here to get your distal or distals. But that is really – it’s there, it’s been talked about, so we can be complete. But that’s not really endodontics; that’s hero stuff; only a few people can do that and they have to have a lot of technology to do it. And then of course I question; are you really doing what’s best for the patient or are you really into your ego about you’re really minimally invasive? So the ones we’re left with is something around a ninja – smaller than maybe you were taught in school, based on the year of graduation – and then a complete access. But the truth would probably be it’s somewhere between the ninja and the complete for most dentists today.

But I want to have you come back to looking at not only the endodontic part of it, but I want you to evaluate as the restorative dentist, what would be most important if you’re trying to create fracture resistant teeth? Well I would still say it’s good to get in. I’m going to come back to this article, but I want to bring special attention to my friend, Marco Martignoni, and Simone Grandini. We’re back to the Italians again, aren’t we? But a lot of research has come out of there, and basically the essence of their research is any restoration – any restoration that comes over the marginal ridges and becomes restorations like an MOD amalgam, that’s when you have really reduced the fracture resistance of teeth.

So it’s not so much – the paper’s highlight was it’s not so much the size of the access. It’s pretty much what is the history of the restorative effort and the caries that prompted the restorative effort. And fillings that go over the marginal ridges like MOs, or like DOs, or like MODs; those are the biggest predicators for having those mesial to distal fractures. Separating the tooth into a buccal and a lingual half.

So we sometimes can even look down these axial walls, and you might see a little line or something; like coming across like this and it gets faint. And we fret about that, we worry a little bit, we probe very meticulously around the circumference of the tooth to see if there’s any extension into the attachment apparatus. But more or less, you’ll see a lot of cracked teeth that come in that need endodontics. The question is, what is the extent of it and is the restorative – let’s not talk about the endo right now – is the restorative able to address those incomplete fractures?

All right. So we’ll probably get off black. All right. Let’s really look at this. We have a complete access. You’re basically thinking about de-roofing the pulp chamber. And you’re basically thinking about this triangle of dentin. You’ve got to bring the file in from the anterior, you’ve got to stand it up and thread it back in. And remember, the entry angle of these canals is bending sharply into the pulp chambers. In the distal you’re coming in more gracefully; you’re coming in over the top of the tooth and you’re angling right down in, and you can do a lot of work here in the mesials.

So sometimes you can cheat a little bit. If you’re coming into the distal, it’s going to be an easier angle in here and you can maybe have a wall a little bit more like that, and you can maybe go a little bit more like that and have a smaller access. But these are decisions that you’ll need to make chairside; because again, most endodontics is done by general dentists in the United States – 85% roughly; 80-85%. That means most of those dentists doing those root canals are also responsible for the restorative effort and protecting the tooth against longitudinal fracture. So you can tip walls back based on access and getting into them. Some walls don’t have to be flared back on the distal. Like this is flared back; and again to be redundant, you might angle a little bit like that.

All right. So we are talking about endodontics, but the one thing that is really causing the controversies, the discussions in the marketplace and the magazines and the journals and in textbooks, is pericervical dentin. And the rhetorical question I’d like to ask all of you is, we almost worship – some people almost worship – a few people, a small group of people almost worship pericervical dentin. So the question I would ask of them, the worshipers of pericervical dentin; is all pericervical dentin the same? Is the buccal and lingual aspect of the pericervical dentin, is that the same as the mesial and distal aspects of the pericervical dentin? And the answer is a resounding no! You need to go talk to John Kois, Frank Spear, Cherilyn Sheets. I mean there’s a lot of dentists out there that are restorative dentists that pioneered procedures all over the world. They’re known as world-class prosthodontists. And it’s funny how the endodontists sometimes are trumping the restorative prosthodontists, the specialists, the experts, because of a lack of knowledge.

Let’s be more clear. I take the triangles out. I just will be redundant. Maybe the distal root; you can angle down in here properly and you can say well, my access could be actually – see, here’s the orifice – it could actually be back like this. And you might actually be like that. Okay, that’s fine. That’s fine, because you can come right in; you can come right in. You would probably come like this; you’re going to have an easier time getting out the pulp. It’ll probably spoon out, and during your disinfections cycles, you can probably get the rest of it; the remnants of it.

But coming back to the whole point. Let’s take that mesial root off and let’s just take a look at it in its cross-section. Everybody knows about the famous what? The famous furcal side concavity. And in here you can see it quite nicely as we scallop around the tooth. But this is the furcation. And if you think about that, and you think about how these canals bend into the pulpal chamber and into the pulpal floor, it’s no wonder that the distance between the canals and the furcal side is less than the distance from the canals to the outer wall. These are not equal. These are not equal.

So if you know that and you drop a file in here and you decide to shape this canal – just going to shape this canal – most dentists just drop a NiTi file in there and they begin shaping; and their preparation expands uniformly around the axis of orientation. So if you’re uniformly opening this up, it’s probably no wonder since they’re not centered in the mesial/distal dimensions of the root; we’re really worried about pericervical dentin. Lots of concern expressed about pericervical dentin, but nobody’s expressing this. So drop a file in there, shape it; it’ll be shaped around the axis of orientation; the preparations are known to drift towards furcal danger; and now you have very thin walls.

This is delving a little bit deeper; we didn’t talk about that. If you’re looking at Kuttler’s work, many people have studied post endodontics, post shaping. Looking at cross-sections, what’s the residual remaining dentin on the furcal side? And it’s not much, and you need to shoot for greater than 1mm certainly. But a lot of these preparations, according to some of that research, were like .8, .9, 1mm. That’s dangerous.

And so if you do what we’ve been talking about all these years, brushing, brushing, brushing away from furcal danger, brushing towards the greatest bulk of dentin, brushing to the outer wall. The name of the canal you’re in is the wall to brush. You’re in the MB, you brush out to the MB. If you’re in the ML, I’d like you to be brushing out to the ML. But this one didn’t.

So when you start to look at all this, and you look at the research I showed you last season, it was a Catholic university in Leuven, Belgium. And it was called Paul Lambrecht’s group; and they sent me teeth if you’ll recall. And they ran the cameras around the teeth, they had taken 2500 images, they had modeled the tooth, they had a three-dimensional; they sent the tooth to Ruddle, Ruddle did his clean and shaping, sent it back to Belgium where they ran a camera round the tooth, took another 2500 pictures. They then modeled all those slices and they have a rendered tooth, and now we could compare before and after. We could just superimpose them. We found out there was about twice – in the research I presented you, we found out that there was about twice as much internal dentin on the furcal side with a brushing technique. And all this time you thought Ruddle was brushing just so he could get those files that are coming out of here off axis. You were trying to – boom! Ruddle was trying to get it over here and get it on axis. So you come right down in there.

So we spent a lot of time talking about that. That was the endodontic part of the straightline access. Now we’re talking about more spinning it to the restorative side as we delve deeper.

So there is advantages to brushing. We have shown conclusively in furcated teeth; the canals are never centered in the mesial dimensions of the root. That means when you drop files in, the preparations just get bigger around that axis of orientation. So if you begin to brush and think about these things and start with the end in mind – root to tooth; isn’t that the clever little – wasn’t the little R2C, root to crown – wasn’t that the whole little gimmick? Well if you are thinking like that – start with the end in mind – then you’re going to be thinking well maybe I should brush away so I have center preparations; so I’d have more remaining dentin. And what I’m going to talk about that everybody’s talking about these fracture resistant teeth; I mean you start having thin walls and all of a sudden post treatment people start oh, it’s a little sore when I bite on it. It doesn’t probe yet, it’s way too early. There hasn’t been enough osteolytic activity to have breakdown and develop a loss of attachment where a probe can slide in, and now all of a sudden you’ve got a pocket, a narrow defect.

So if you want to prevent fractures – and we’re talking constantly in the literature about minimally invasive endodontics as it relates to fracture resistant teeth. So all of a sudden it became vogue to leave the pericervical dentin. Don’t remove the pericervical dentin. We have NiTi; our NiTi is e-traded. It’s post machining. We put them in the ovens, we have flexibility, you can’t believe it, there’s no more shape memory, you guys all love that stuff. Well you know what? There’s also the restorative dentin. So you’ve got to learn to balance things in life. It’s not this or that; it’s usually something kind of in the middle. So that’s a disaster.

I’ll show you one other thing. So here’s our off axis. You know when you throw files, those early instruments into furcated canals in the posterior regions, the files come out off axis based on your preoperative film. And that means you’re already cutting on the wrong wall; you’re cutting towards the furcal side. You’re cutting towards the furcal side. And yeah, you get a nice little shape going and you just didn’t remember the cross-section and how things drip. So what I want you to do and what I still want you to do is we can have the restorative effort absolutely blend in beautifully with the endodontic effort, and together we’re going to be greater than we were. We’ll be addressing the endodontic challenges, and we’ll also be addressing the restorative challenges.

So get those files up righted, because all the research I’m aware of shows that when the files come down through the coronal body of the canal on axis, there’s less ledges, there’s less blocks, there’s less iatrogenics, there’s less broken instruments, especially when you’re dealing with a lot of curvature deep. So straightline access is still very relevant.

But you’re going to lose a little bit of this precious – maybe we should write the word “precious” – precious pericervical dentin. But while you’re worried about out here, Ruddle’s worried about in here. So does one worry trump the other worry? I would say yes. When you start to talk about wall thicknesses that are less than a millimeter, we have the evidence. Well you’re going to say wait a minute Ruddle. If you start to get straightline access, what if this becomes less than one millimeter? Stay tuned. Stay tuned.

So always in the context, what are the advantages, what are you gaining, what is the get on this? And the get is you can immediately get these canals opened up so you can visualize them and begin to get ahead of the game. You can immediately get rid of all your little impediments – the triangles, the irregularities – and you can match the orifice and line it right up with the internal axial walls. So you can slide right down the walls with your eyes closed, and you can transition into a pre-flared canal. We already talked about it, but if you’re brushing and you’re doing it deliberately and slowly. I didn’t say brush 50 times on the outer wall; I didn’t even say brush 3 times, did I? You brush until you get the handles upright. All right? It’s not a number. It’s like Doctor, I can look across the room – you’re off axis! You’re on axis; good for you! Go home, please.

And then finally, once you get the body of the canal opened up, we find in the literature again – we find out that all doctors do better in the magical apical 1/3. Coronal, middle, apical. Divide your roots into thirds. Each zone, as we’ve talked about endlessly, is about 3,4 or 5 millimeters. So that last part, the part that we usually that’s a problem, it’s apically. How many times did you look at your pack and say geez; I hate my coronal 1/3. Geez, my middle 1/3 is really bad today. No. You’re usually short, you’re long, you’re ripped, the canals didn’t dry well, there were bloody canals. When you pack there isn’t resistance for them, so cones sail and the case fails. We have to think about all these things and revisit them from time to time, because it will keep us on task so we can make adjustments to bring the case into a successful conclusion.

So those are your advantages. I just plucked one single paper talking about the influence of cervical pre-flaring and the incidence of root dentin defects. Read the paper! It builds a case for getting triangles out of there. I’ll talk about why you’re so – well Ruddle, Ruddle! I’m still worried right here. I’m very – I better do a different – I’ve got to make it really obvious. Ruddle, we’re really, really worried about this little zone. Okay, well keep worrying about it, because that would be your nature. But what if you had a way to think about it that all of a sudden alleviated your concerns?

So Shaper X, this is from the ProTaper family of instruments. The Shaper X is still the number one instrument in the world for pre-enlargement. A lot of companies make a version, because they’ve borrowed from this concept. But the Shaper X – it could be Ultimate, it could be ProTaper Gold or ProTaper Ultimate because there’s an SX, an auxiliary shaper. It’s auxiliary. It’s not used on every case; it’s just used when you’re off axis as an example. Or you want to get the body opened up quickly.

So we’ve looked at this in the context – divide the instrument into thirds. It’s progressively tapered, it’s cutting away from its tip, it’s cutting towards – it’s bigger, stronger and more efficient blades, it’s cutting right where we want it to cut. It’s cutting right in here, taking out that triangle right in there, getting this all flared and opened up so you can now take on the nice challenge of curvatures and re-curvatures in the apical 1/3.

All right, cross-sections. We’ve talked about all that before, but it’s a changing cross-section, it’s a changing taper. You can see some numbers here at the various locations of diameter along the active portion. But this instrument, most orifices when you drop into most teeth; when general dentists drop into the vast majority of all teeth, the orifices are already bigger than a millimeter. So please don’t tell me about minimally invasive endodontics. That’s just the way they come.

Now we do know there’s mineralization, there’s calcification, pulps pull down. Yeah, that’s another discussion for another day. But most canals, even when they need endodontics later in life, that orifice is already a millimeter. So you can use this instrument very intelligently, based on the anatomy, with a reflection back to your X-rays and your CBCTs that you have, or your tomosynthesis, to kind of look at these things in different ways – frontal, axial, sagittal – you can start to map this all out; measure twice, you can only cut once.

Now I want you to notice the flexibility of SX. I saw some other instruments, and I tried them all, and they’re like stiff as a 16-penny nail from Sears & Roebuck. Notice how that tip – that whole instrument is dead soft. It’s flexible. Notice I’m brushing; I’m not drilling. I’m brushing away from furcal danger. Notice the furcation in here. Notice that deep concavity. Well in just that kind of time – there were no edits there – you can see at about 15, 20, 30 seconds, the body is completely opened up and you just have the apical 1/3.

So that’s the power of pre-enlargement. And then moving the canal away from a root that has a cross-section that would look like that. So when you’re getting this moved out, you’re going to be like this and you’re going to come around like that, but you’ve protected the furcation under the crown.

So you have the famous triangle – I’ve just been pounding on this and I’ll pound on it a little bit more – but your access will probably come in like this, like that, and this is what we’re talking about. I said I’m a little bit more forgiving if you want to leave the distal pericervical dentin. But where is it most important? Again, I’ll be redundant, watch the arrow. Brush. Brush with this instrument and brush away from furcal danger. Brush away from external concavities, brush to the greatest bulk of dentin, end up with more centered preparations and more fracture resistant teeth. So much of this, with a few new delving deeper nuances, you already have heard -- from Ruddle anyway.

Now let’s go to some very simple drawings that I had fun making. I decided to crank out some drawings, take a picture of them, sent them off to my multi-media team, and here you go.

So I have been pounding to death. You have horns, the canals bend in, they bend into the pulpal floor. And when we make access, there’s a lot of you just like to do this stuff right in here. Now your files are coming in at awkward angles. Already you’re starting to lose all the advantages of removing the triangles. Go back and look at those clips; go back and look at those shows – there’s been even more than one show. But I would suggest to de-roof the pulp chamber. You don’t have to come clear to here; that might be an exaggeration. But I would say to you; you should be coming, with your endodontics involved, like that. You can flick that out with an explorer and that will come out; the rest of the tissue will be eliminated out of that horn with your flushing and voluminous irrigation.

And then I said you don’t have to come down just necessarily like that – you could – but you could just consider doing it a little bit different. And you could even think about the angle, and you could go well, I can go kind of like that.

Now that’s reversed architecture; we’re smaller up here than we are at the floor. So post-treatment if it’s more than one visit, you might have the filling collapse against the cotton pill in the chamber. So we kind of like to have a little divergence in the walls – a little divergence in the walls – so we have a nice restorative given the fact that it’s more than one visit. It’s less important if it’s two visits, because you’ll put your bonded composites and amalgams and whatever you’re using in those chambers. And you’ll stuff and protect your orifices in case there’s coronal leakage. But basically if it’s one visit, you don’t really have to worry. Are you like this, like this, or like this?

Well, we’ll slide it over and get all three views. So there’s where you cut your access. As an aside; when teeth fracture – and I’m talking like – I’m not talking about the zebra. I’m talking about it’s North America, I hear hoofbeats, it’s horses; it’s not a zebra. So let’s talk about horses. Most of your teeth are going to fracture something like that. They fracture, I’m trying to say, mesial to distal. And we know that we see them sometimes, the evidence of the fracture over the virgin marginal ridge, so you’ll probably see that clinically. You’re looking for it in your axial wall. Does it get faint or does it play out? But I’m saying fractures occur mesial/distal.

Think about pericervical dentin. Where is pericervical dentin most important? Is it mesial that it’s most important? Or is it distal? And the answer is – can you see this? No! No. The most important part of your pericervical dentin is buccal and lingual. And we’ll look at the next drawing. Because we need to squeeze these elements, these tooth elements – buccal and lingual – a crown. And if you prep this, when you put the crown on here – oh, I love this part. Well look at; you got a big chamfer here; that’s gripping. We’re talking about the ferrule effect. Now we’re talking about a ferrule. And I don’t hear hardly anybody that’s so into minimally invasive endodontics; how come we’re always talking about adhesion dentistry, and I use this and I use resin modified glass ionomer, and I use a glass ionomer, and I use Filtek, and I use whatever you’re using. I use the dual cure. I don’t hear of the old fashioned, yet absolutely relevant ferrule. F-E-R-R-U-L-E; can you say it, can you spell it, do you do it? So the Ferrule Effect is what squeezes our tooth together and prevents it from the occlusal loads that inevitably can invite and promote fractures.

So when you have the upper cusp coming down, it would typically the mesial lingual cusp tip – the MLCT of a maxillary molar – it’s going to come right down and it’s going to seep right in that central pit, and it’s going to pound that tooth, and it’s going to tend to want to do this, and it’s going to tend to want to spread those teeth out, and we can see propagation. When our fractures get sub-crestal, they’re generally hopeless. Fractures that play out super crestal can be treated; with some risk. Obviously, the closer you get to the bone, the greater the risk. Also, the occlusion needs to be adjusted so that no particular tooth gets a heavy pounding load.

So I want to talk about this, because our loads – our vertical loads are over 1200. I don’t know why I’m getting lines through there, but it’s a thing of beauty; I’ll try it again. Our loads, our pounds per square inch (PSI) are somewhere around 1200 -1400 pounds per square inch. So those are huge loads. And then when you get something between your teeth and really – like something really hard and you’re trying to break it, crush it. You’re eating; you’re putting big loads on these teeth and you really need to have this right here. Notice that that might be called about a 90° chamfer; that’s a chamfer. This one might be over here; this one might be closer to a 60° chamfer.

But anyway on those chamfers, that’s up to the operator. You can put a little heavier chamfer if you have a bulk of tooth structure. If you’re a little thinner over on the lingual and you don’t have quite as much tooth structure in here, you might have to make a little shallower chamfer. But in any event, we also know that the ferrule needs to be 2-3mm. You can get away with 1-2mm ferrules, and this would be more like on the mesial and the distal. You don’t – you want a bigger or longer ferrule on the most strategic part of the pericervical dentin, which is again buccal lingual. When you bite down, you go into work and balance; you’re rocking those teeth. Buccal, lingual; trying to split them into two halves. So that’s how we can manage the buccal and lingual walls. This is critical tooth structure; critical tooth structure; critical, critical, critical.

Well guess what? What is less critical? I guess you already know the answer. It would be called the mesial and the distal. And by taking out the triangle – remember we had a triangle in here; remember the pulp horn used to be like this? Like that? Well, by getting this triangle out of here, yeah; you’re losing mesial tooth structure, less on the distal. But that’s not the strongest part of the ferrule. In fact, from my reading in various prosthetic articles just in preparation for this show, a lot of your restorative dentists are going to knife edges. They’re not going to chamfers. Because they don’t have as much tooth structure; they don’t want to come down and do that. Because that’s making this wall leak. It’s a little bit weaker.

So there are restorative ideas. Obviously, adhesion dentistry is huge, so don’t hear me say that that’s not important. But I’m saying the mechanics is equally important; the Ferrule Effect and the pericervical dentin.

So I read about pericervical dentin. When I read some authors say precious pericervical dentin – let’s not minimize it. Let’s just look at it and let’s just have an intelligent conversation that’s not so emotional. Let’s get the triangles out. Why? Because it grows up endodontics. It helps all endodontic people – that means general dentists and specialists alike – it helps them visualize the floor, find extra orifices, glide path managements grow up, shaping becomes more predictable, the armamentarium for disinfection and not filling root canal systems can be easily brought in by all dentists – they don’t have to buy $100,000 technologies – they can do it very affordable for the cost, for the patient. Okay? It's about people.

So remember. The loads are buccal/lingual – buccal and lingual – and so that makes by definition your buccal and your lingual ferrule of the pericervical dentin, the most precious. I didn’t think I’d even say it would be precious, but that would be precious. But it’s not so important here, and it’s not so here. Because teeth don’t rock so much mesial to distal during eating; they rock buccal to lingual. Now if you take out the second molar and you’re biting in here, yeah, you might want to have a little bigger ferrule to try to hold that thing together.

I’d like to say one last thing. I have flapped several teeth in my life that had been failing endodontically, and I’ve seen a fracture that’s faint and then it gets bigger. So I guess I could just show that. And it gets bigger. I guess I’ve got to really hit that button. More overt, and then getting very faint.

Now you’re saying, Ruddle; that sounds like a buccal lingual fracture. It is. And those are from endodontic loads during obturation. They’re usually from spreaders or pluggers that bind needlessly on unyielding dentinal walls. And then those fractures when you pull the flap down and you see the dehiscence and you curette out the soft tissue – we’ll show these in our Microsurgical Continuum – but you’ll see those fractures, very faint – that’s why they didn’t probe. And then as you drop down, you see the fracture can sometimes even have separation. So those are iatrogenic fractures, and today we’re talking more like occlusal loading fractures versus iatrogenic.

So in closing, I am emphasizing that we went from the preop to the postop. I’m taking out this, because I’m doing that. So that means that this is gone; this is going to be gone. I’m going to pick up my endodontic abilities and skills, because I’ve made life easier. On the other hand, I have restorative efforts that can overcome removing a triangle. And it’s not the mesial pericervical dentin.

We’ll look at this case and then we’ll be done. Just one case. So here’s our preop – these are big, big molars. I mean this is a guy that had very formidable preoperative imaging. You can see significant curvatures of not only roots – remember the canals are more curved than the roots that hold them. You can see systems that break off and bend. I’m doing this guy right here; it might be helpful if I had this color, I’m doing the first molar. It’s breaking down, you can see the extension, but the roots are going to be like 26-27mm long. And that’s with the crown.

So you begin to see the usual things we look for. You’re looking at the crown, the margins, the restorative. You’re looking at the cull area; you’re looking at all this stuff. You’re moving your cone in different horizontal angles so you can see different views. You’re starting to see a little line like this. You’re starting to see a line like that. Well you’re already thinking there’s a concavity. Oh, I’m already seeing the canal; it’s starting to bend in. And you can imagine there might have been a pulp chamber that looked like this. And so there’s that triangle, right there.

So if we slide this over, you’ll see we already see this. We see it on the preop film; I’m already plan, visualize, execute. Well maybe think, plan, visualize, execute.

And the execution is treating the root canal system, and then at about a 25-year recall – this is about 25-28 years out – you can see good bone, you can see it’s posted properly, we beveled the post for the clinician because I don’t like the posts that come down and have shoulders. These create fracture propagation lines. So we can mill that stock post in chairside with a transmittal burr in 20 seconds, and we can make it fit the shape; versus making the shape fit the post.

Look at the multiple portals of exit, furcal canals to furcal lesions. But notice you still have sufficient dentin, you have more of a knife edge on this crown, so this preparation would be more like that. It would be quite thin on your metal here and it could be quite thick back in here. And then the real – the real precious pericervical dentin, the real ferrule, is buccal and lingual.

So I hope this helps you a little bit as we delve deeper today into straightline access, but with an eye towards restorative dentistry.

All right. We thought we would close our show today with another Ruddle Flashback Story, because it’s been a while since we’ve done one. And I was trying to think, well what story could my dad tell? And knowing that this year, 2024, the Olympics will be in Paris, I started thinking well, wait. You’ve been to the Olympics, right? Why don’t you tell your Olympic story from 1984; the year that Fabio graduated from the University of Milan?

As a gold medal endodontist, I’ve been told – so the audience sees – I’ve been told this is a 5-minute segment, Cliff. So I was going to talk about everything I saw, but okay, very quickly. This wasn’t anything I saw, but it was really cool. Because Rafer Johnson, who won a gold medal in Rome in 1960; he was the guy that lit the cauldron.

Where were these Olympics?

In Los Angeles.

Okay.

They were just down the road.

The 1984 Summer Games?

The 1984 Summer Games were in Los Angeles. And it was one of the only games that made money; they actually make about $223 million because we had so many venues in southern California.

Anyway, Bill Borgers – so my assistant was a nice lady. Her husband was in the citrus business; his name Bill Borgers, and we had decided to go to the games, and no tickets were allowed. We were just going to wing it. And there was a lot of concern with traffic and all that, because they had mentioned this a lot. But on Friday, August 10, we got in Bill’s car and about 7:00 or 8:00 we were on the road. We got and were parking in an hour and 15 minutes at the LA Colosseum, which was the heart of the campus of the events. And we were so excited, and we got our car parked and we started walking, and there’s people everywhere. And we decided you go to the Colosseum. That’s where you go, because we didn’t have tickets for anything.

And we got right in. We just paid and boom; right in. We got good seats, walked down. We were probably about five rows up from the first row, and that means we looked down there and all of a sudden, the women were lining up for the 3000 meter. And my dad was in track and field – we can tell those stories later – but he did hold the Boy Kansas City Mile for a while.

Anyway, through him I was into track and field – Carl Lewis – and we noticed; that’s Mary Decker, the very fast human being. She liked to run the 800 meters and all the races between 800 meters and 3000. So she was down there stretching up, and all these other ladies were around her. When I say ladies; she was 17. And I noticed somebody next to her that wasn’t so far away, and they were barefoot. And I thought Bill, Bill; she’s barefoot! Anyway, but that was Zola Budd.

So anyway, the race starts; they’re going around the track, several laps as you would imagine. And about three laps to go – it wasn’t the bell lap, but about three laps to go. The pack had kind of spread out and there was the little leading pack, about three or four women. And Zola Budd was right there with Slaney. And Budd had maybe a shoulder on her, and she was running on the outside. Slaney was on the inside. And on the turn, Budd came over and her left leg hit Slaney’s right leg, and Slaney went down in a pile. Mary Decker went down in a heap. And I could hear her screaming. And I didn’t think it was so much pain as I thought it was emotional. Because if one thinks about what you do to get to that moment, and the hours and years of work, it’s pretty amazing. Anyway, she went down; she lost the race. Budd came in 7th, ironically. And I don’t know if it even matters, but some other woman won the race from Romania.

So I wanted to know for this show whatever happened. Because there was a lot of anger, I remember, in the press for quite some time and then I just quit hearing about it. But they got together 32 years later, made up, and became really good friends.

So that was a real highlight. I saw Carl Lewis run one of the preliminary heats. He won four gold medals; he won the 100 meter, the 200 meter, he won the 4x100 and he won the long jump over 28 feet. So anyway, he was quite an athlete. You can Google Carl Lewis. So I got to see Lewis, I got to see Mary Decker.

And then on the way out we thought well, we’ve got to see something besides track and field; because there was so much going on in the Colosseum. There was steeple chase over here, discus, javelin, decathlon. But we went by this big auditorium and we heard a lot of noise coming. We ran in and got our tickets, and all of a sudden we were looking around and we’re in the Korean section. And all these people are waving Korean flags, because their middle weight was fighting and he won the gold medal. We didn’t see the gold medal match; that was a preliminary match. But we saw him. And anyway, that was a terrific game. So I’ve always wanted to go back – maybe with you perhaps in 2028 – because -

Yeah, I wasn’t invited in 1984.

Where were you in 1984?

I remember. I was 14 then, and I remember you were going to the Olympics.

Wow, okay.

Yeah, when you were just telling the story, when you were saying they were running the 3000 and they’re coming to maybe the third lap. When you’re running a race that big and you get right down to the last lap; just even when you described it, I felt like the excitement. You’re getting right down to there’s going to be a winner soon.

Oh yeah. It was really a thrill. The crowd was big and noisy. Because the Colosseum seats over 100,000 people. So it was a great venue, traffic was light, the drive home was uneventful, and had a good experience.

Well the Olympics are really cool, because you get to see sports that you don’t normally get to see on TV. Like I never watch track and field, except for at the Olympics. And I’m not watching volleyball, except if we’re watching the Olympics. Or even swimming; I’m not watching it unless the Olympics is on.

And I just wanted to tell Pierre that I’m coming to the Olympics in 2024 – this is in Paris. I’m coming as an endodontic athlete. And Pierre; if you would join up, we could have a whole bunch of international endodontic athletes and we could see who gets the gold, the silver and the bronze.

Okay. All right. Well thank you for that story, and see you next time on The Ruddle Show.