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AUDIO - HSP #138 - David Rudo
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VIDEO - HSP #138 - David Rudo
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Regarding Ribbond, Dr. Rudo says, "Necessity was the mother of invention". In the early days, Ribbond was barely recognized. Now it's way more than just another legitimate dental material.
David Rudo was born in 1935 in Baltimore, MD. He graduated from University of Maryland in 1961, and served in the US Army in Germany from 1961-1963. Dr. Rudo moved to Seattle WA and started a dental practice in 1966, and developed Ribbond in late 1980's. Afterwards, he started Ribbond, Inc., in 1992. He then sold his practice to work full-time with Ribbond, Inc. Dr. Rudo currenty runs Ribbond, Inc. with his daughter and son.
ribbond@ribbond.com
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Howard Farran: It is a huge honor today to be lecturing David Rudo, who I have been seeing at every major convention, for probably 28 years. You always have your bicycle, and by the way, that's why you look so rocking hot at 80 years old, is that damn bicycle of yours. I mean, when I lecture around the world, all the countries where the people have to walk to work, or they walk to a train or a subway commute, all those public transportation systems, they're all ideal weight ... You almost can't find ... I'm always the fattest person in any of those cities. If anybody says what type of diet you should be on, or how you lose weight, I mean, travel around the world. It's your car.
David Rudo: Yup.
Howard Farran: It's your car. A car causes obesity. It's not protein, or fish, or the Mediterranean diet, or any of these crazy stuffs, because you go around the world, they all have a different diet, and they're all lean because they're all ... Most of them have to walk, like, two miles to catch the subway or the train.
David Rudo: Yup.
Howard Farran: And then it only drops them off, you know, one or two or three miles ... I'll never forget the first time I went to Cologne, Germany, and I was staying in this three or four story bed and breakfast hotel, whatever, and this ... You're 80 ... This, about 80-year-old lady is riding down the street on her bicycle with a basket of groceries, gets to the door, hops off her bike, puts the groceries in one hand, lifts up her bike with the other, kicks the door open, and then skedaddles up three flights of steps.
David Rudo: That's Cologne.
Howard Farran: And I thought, "In America, you'd be either dead, or on 10 medications and be telling everybody, you know, you have some medical condition. So you're just, you're a rocking hot role model for me in so many ways. And I've really enjoyed your friendship over the years. So, tell us this: You graduated from the University of Maryland in '61, which was the first Dental School in America, correct?
David Rudo: And it was still taught ... Dentistry was still taught the same way when I was there.
Howard Farran: And, how did you go from being David Rudo, the Dentist, to the master mind whiz kid behind Ribbond?
David Rudo: Necessity was the mother of invention.
Howard Farran: And what year was that?
David Rudo: Late 80s. I belonged to a Periodontal study club, whose mentor was Irving Stone, one of the immortals of Perio. He was also one of the founders of the Academy of Osteointegration. So, I got involved in implants. I always was interested in occlusion. So, I would make long term provisional implant bridges and try to refine the occlusion by eyeballing it. And, the provisional bridge, the acrylic bridges, would break like acrylic bridges do. So, I came up with this material, with a lot of help from friends. And I ended up with something that works.
That's how Ribbond was born. I wasn't looking for a product. Product wasn't even on my mind. Product came in later. So, after ... From provisional implant bridges, I got involved in periodontal splinting. That turned out to be the standard in periodontal splinting. It's used for all kind of things now. The main use is going to be in composite restorations. Using protocols that are promoted by the Academy of Biomimedic Dentistry, and I'll have some examples of that in here.
So, that's where the future lies, in my opinion.
Howard Farran: So, you brought today 17 slides, and I love this because even ... You've always been a pioneer, and now you're pioneering on my podcast. I think this is like, number ... What number is this, John? 130? 120. And, leave it to David to be pioneering. This is the first time I've ever had an ipad next to me with 17 slides. So, you're looking at these same slides on your ipad?
David Rudo: My slides are over on the computer off to my right ...
Howard Farran: So, you want to go through this first? Or, how do you want to do this?
David Rudo: Yeah. This will be a good start. And, if I get too carried away with explanations, call me on it.
Howard Farran: I'll actually get on my bicycle in Phoenix and ride all the way to Seattle.
David Rudo: Too hot for you in Phoenix. You've got to get out real early in the morning.
Howard Farran: I do. I work out every morning at 5:00, because I swear by 8:00, it's just too hot.
David Rudo: Yeah.
Howard Farran: And it's weird because if you go on like a 4 hour bike ride, you know? 5:00 - 6:00, you don't even drink water. 6:00 to 7:00, maybe one bottle. But by 8:00, you're like a bottle every half hour, and it just zaps the energy out of you.
David Rudo: Yeah.
Howard Farran: It's amazing how the sun works.
David Rudo: I grew up in Baltimore. I grew up in Baltimore, where it's humid and hot. So, I had to get away from that.
Howard Farran: So, are you still a Baltimore Ravens fan? Or did you switch to a Seattle Seahawk?
David Rudo: Actually, I'm neither. I'm not much on spectator sports. It's not my thing.
Howard Farran: It's not ... Okay. So, slide number 1. How do you pronounce that?
David Rudo: Maurizio Grande. Maurizio Grande is a Dentist in Rome. And, I ... Let me mention this in the beginning. Pasteur said, "Chance favors the prepared mind." So, if you have some ... Your mind is prepared, you may have better luck. Maurizio Grande is a Dentist in Rome. He has been using Ribbond. He does a lot of immediate load implant bridges. So, I used his case as the example of what I did in the beginning, reinforcing provisional implant brides. My original pictures were so crude, it would take a lot of explanation to describe them. So, that's a good example that you're seeing there.
This [inaudible 00:06:24] rigid dark stabilization that you need for immediate load implants. I was actually the first general practitioner to become a full member of the Academy of Osteointegration back when you had to present cases. And that's what I showed. So, that's the example of it.
Howard Farran: So, slide 2, it says, "Effect of Bondline Thickness."
David Rudo: Okay. That's a slide made by my mentor, Vistasp Karbhari, who was a structural engineer with a PhD in fiber composites. He intellectually adopted me. I would say, when I wrote him ... When I got started, I wrote away to six or seven fiber composite research centers, and he replied. He's now the President of the University of Texas in Arlington, near Dallas.
That slide shows the thinner the bondline is, the stronger the bond is. The thicker the bondline is, the weaker the bond. And this is the basis for almost all fiber composite structures. In fiber composites, it's a system. The fiber, the resin that holds it on, and the substrate, in our case, is the tooth. So, that is a clear description of the principle. And that's why I keep pushing the thin bondline. That's what makes Ribbond so effective. You can adapt it, right up against the teeth.
Howard Farran: Pretend you're talking to someone just with headphones on.
David Rudo: Okay, slide 2 shows a graph. The vertical axis, I think is ... One of the axis is Strength, and the other is Thickness. So, it shows, the thicker the bondline is, the weaker it is. Conversely, the thinner the bondline ... The thinner the amount of resin between the tooth and the fiber, the stronger it is. And that is a universal principle of laminates. You're familiar with porcelain veneers. The reason they fail is not because the veneer itself is weak, but they de-bond when it's not bonded smack up against the tooth. With an orthodontic bracket, you want to bond it smack up against the tooth.
There was a poster clinic at the Academy of ... American Academy of Orthodontia showing how much more preditable ... How much stronger the bondline was when they put Ribbond between the bracket and the tooth. The bond got significantly stronger and much more predictable, so that's thin bondline principle. The graph describes it cleanly.
On the next slide is the same writing, but it describes when we're doing composite restorations, we want to have the Ribbond smack up against the tooth substrate, lining the pulpal floor. [inaudible 00:10:04] Preliminerization shrinkage and shrinkage stress. That's slide 4 ... No, 3.
Howard Farran: That was 3. Now you're on 4.
David Rudo: Now I'm on 4. I'm showing making ... From our instructions for periodontal splint, you want it smack up against the tooth and deep, deep, deep into the interproximal contacts. This ... When people have a failure with periodontal spints, using Ribbond, it's always they don't have it smack up against the tooth. The composite, the looting composites that they're using to hold it on is too thick. When people tell me about a failure, I'll ask them, "Is there any composite on the tooth?" If there's composite on the tooth, that tells me the composite was too thick. If there is no composite on the tooth, that tells me their bond to the tooth was not good. The composite always sticks to the Ribbond.
So, that is the key to success for periodontal splints.
Slides 5 and 6 are the work of Paul Lin, the Dentist in Taiwan who teaches all over the world. 5 shows a clinical ... The oral picture and the radiographs, and the radiographs, you can see in the before ... He splints the teeth with Ribbond and he is meticulous with his root cleaning. In slide 5, you'll see there is no bone around the tooth lower [inaudible 00:12:08]. After splinting and root planing, the bone has returned. He regrew the bone.
6 shows a case, where you see basically no bone, but I think in the centrals. And, it's 12 years later, with root planing and Ribbond stabilization, you can see a lamina dura in there.
Howard Farran: That is just amazing. I don't even see this good of before and after pictures with Lanap. Lanapp, you see something like this, where severe perio has been reversed, you know, cleaned up, bones come back.
David Rudo: Yeah.
Howard Farran: But this, is just even more amazing. I wonder if he splinted the teeth and did Lanap? Do you know?
David Rudo: I'm not familiar with Lanap, but he does, basically, root planing. Meticulous root planing. Ray Yukna uses this for his laser treatments.
Howard Farran: Wow. That is just an amazing picture. Yeah. Very good.
David Rudo: And Paul Lin's picture shows it 12 years later. That's 12 year follow up.
Howard Farran: Mm-hmm (affirmative)
David Rudo: You couldn't ask for anything more.
Howard Farran: Well, it makes sense on periodontal disease. I mean, I'm a farm boy from Kansas. I mean, if you went into a fencepost and grabbed the top of that fencepost and just started rocking it back and forth, it doesn't take long and then you can just lift that thing straight out. So, having ...
David Rudo: Yeah.
Howard Farran: Instead of having, you know, the crown-to-root ratio being one part crown to two parts roots, once you're at 1:1 or 2:1, the tooth doesn't have a chance just from pure physics.
David Rudo: There ... Well, don't knock physics. You can't argue with physics.
Howard Farran: Was it Newton who said, "If you give me a lever long enough, you could lift the Earth?"
David Rudo: Well ...
Howard Farran: Was that Isaac Newton, or was that ...?
David Rudo: Whoever it was, it's logical. You get a long enough lever ...
Howard Farran: Are you selling most of this for periodontal disease splinting? I mean, is that the majority role of Ribbond?
David Rudo: I would say, right now, the main use probably is the instant bridge.
Howard Farran: The instant bridge.
David Rudo: Which is a periodontal splint, but a periodontal splint with eponic [phonetic 00:14:51] in there.
Howard Farran: And is the eponic the extracted tooth they just removed?
David Rudo: It's the best eponic you can get.
Howard Farran: That's what I always like to use.
David Rudo: Shades good. Shape is ... The first bridge splint I ever did, I told her, "I have no idea what to expect. I've never done this with teeth. It may work, it may not." I said, "It's probably just temporary."
She was a youngster. 78 at the time, and she said she was just temporary. Last time I saw her, six years later, that tooth was still in there, and the rest of her was just falling apart ... The rest of her body was falling apart. But that tooth was there.
I say the main use is going to become, though, with composite restorations. It totally ... The slide we're going to see at the end shows a shell of a tooth, where I stained some pieces of Ribbond and laminated it against the inside walls. So, basically, you're building a fiber composite structure within that tooth.
Howard Farran: Are you favoring any type of bonding agent or composite?
David Rudo: We recommend wetting the Ribbond with a plain, old time, original, simple enamel bonding resin with no filler and no dentin primers in it. I don't know ... Because dentin primers could be anything. They could have bubbles, gas, and all kind of other stuff. And with the one-step system, something like 80% of the material is solvents. We have our own, which is a plain, original bonding resin. The least expensive thing somebody could buy. And by not having solvents, the shelf life is ... We have to say the shelf life is two years, but it'll last for a much, much longer time.
Howard Farran: And we talked about physics. That's also a great rule of thumb on chemistry. I mean, you know, in chemistry, they tell you every time you lower the temperature 10 degrees, a chemical reaction takes twice as long. So, in a refrigerator, say your food is on the table, and it's 80 degrees in your house, you put it in a refrigerator that's 60, from 80 to 70 will last twice as long, from 70 to 60 it'll twice longer ...
David Rudo: Yeah.
Howard Farran: So, in freezing, chemical reactions are still going, it just takes much longer. So, all of those shelf lives ... I noticed that the people that are really serious, I mean, about dental materials, even their algenate is in the refrigerator. And, they just ... A lot of people don't understand their instruments. I mean, you can't be a painter and not know how water colors and oils thicken with temperature. I always cringe, living in Phoenix, Arizona, when the UPS truck pulls up and they are bringing in boxes of this or that, and you're thinking, "My God, you know in the back of that truck, it's a 140 degrees," and you're just wondering, "How damn long has my bonding agent been in there?" But when I order Omaha Steaks, it comes in a Styrofoam container with dry ice. It's like, "Why can't my bonding agent come like an Omaha Steak?"
David Rudo: As I said, Pasteaur, translated into English, is "Luck favors the prepared mind."
Howard Farran: Yeah. And prescriptions? Everything that needs ... Your medications? Everything should be in the refrigerator if you want it to last twice as long for every 10 degrees.
David Rudo: Yeah, I mean, the other thing with Ribbond is it's not pre-impregnated. So, the shelf life is indefinite. With the pre-impregnated materials, the shelf life is limited because it's [inaudible 00:18:57]. And with a pre-impregnated, every time you open the package, it's getting light in there, so it's starting to trigger prelimerization.
Howard Farran: Right.
David Rudo: So, ours is unlimited shelf life. And as long as you keep it in the container we package it in, the plasmas treatment is going to last.
Howard Farran: Right on. So, now we're on slide number 7.
David Rudo: Slide 7 is a strange case. The Dentist called, he had this problem of a mobile tooth, mandibular ... I forget, it's a lateral, I believe. Way in labial version. Way out there. And that tooth is getting banged on. That's constantly getting abused. It's so far in labial version and crowded out, that there's really no room to get a sufficient bond to it. No matter how well you adapt the Ribbond in there. There's just not enough surface area. So I explained to him on the phone ... He sent me some pictures, and I explained to him on the phone, cut a channel in the mesial and the distal, at the level of the contact area, and ... Well, cut a groove in there, and cut a channel across the labial. Weave the Ribbond through there, and physically constrain the tooth from being pushed labially. And that's what he did, and he covered it with a little composite. Ribbond hides. It's masked very easily. It's translucent. You don't see it. You can bend it any way you want through that irregular contour, and that physically constrains the tooth from moving.
So, again, Ribbond is a tool. It has no brain. If the user has a good brain, and you don't have to be a genius. If the user has a brain, you can do magic with it. That's an example of problem solving.
Howard Farran: Very good. So then, number 8, you're saying, "The Best Simple but not too Simple Text Marketing B.S. Detector. The New Science of Strong Materials and Why You Don't Fall Through the Floor," by JE Gordon.
David Rudo: That book is used in the UK ... Well, let me say this. I recommend that to every Dental School where they teach Dental materials. In the UK, this book is used not just to teach material science, but to teach the English language. It's written that well. In that book, there's four pages by John McClain, describing enamel as a composite material. And I met John McClain. When I met John, I mentioned that book. His eyes lit up, because McClain worked with this guy during the second World War. And, when you see the craze lines in the enamel, that's basically the principle of composite materials, of the weak interface that we're going to get to next. So, that book ... Even if you can't ... If you're not scientifically oriented, McClain can ... I mean, Gordon can explain it to you. He's that good.
Howard Farran: The New Science of Strong Materials and Why You Don't Fall Through the Floor," by JE Gordon.
David Rudo: Yeah.
Howard Farran: And you mentioned World War. You have to explain how did you end up in the German Army, after Dental School, out of the University of Maryland, in '61.
David Rudo: I was stationed in Germany.
Howard Farran: Oh, stationed in Germany.
David Rudo: A little different. I was not in the Wehrmacht.
Howard Farran: Okay. So that ... That's funny how the mind works, huh? So, the next ... So, you were stationed in Germany. Where were you stationed at?
David Rudo: In ... About 40 kilometers East of [inaudible 00:23:39]. West of Frankfurt area. Near the French border.
Howard Farran: So, was the IDS meeting going on back then? Or was ...
David Rudo: I didn't even know what the IDS was at that time ...
Howard Farran: In Cologne?
David Rudo: Yeah. I didn't, I've belonged to the IDS for the past 20 years.
Howard Farran: Is that your favorite city in Germany, or not really?
David Rudo: Well, I know it better, because I go there.
Howard Farran: That was the farthest outpost of the Roman Empire, 2000 years ago.
David Rudo: Correct. And Kuhn was ... Cologne refers to the Colony. That's what it was, the Colony. Cologne. And one of my favorite restaurants is in Cologne. It's a Lebanese restaurant that has, it's not German food. It's Middle East, as good as it gets.
Howard Farran: Yeah, that Cologne is just an amazing city. You can still see the walls of that Roman Empire ...
David Rudo: Oh, yeah.
Howard Farran: And you can get the best German food. And since it was a part of the Roman Empire, you can also get the best Italian food. I think a lot of restaurants are kind of a German-Italian blend.
David Rudo: They are, yeah. I have a good set up there. The hotel I stay at is near the Damme. And I'd walk to the Messe every day.
Howard Farran: Yeah, like all the Germans.
David Rudo: Yeah.
Howard Farran: It's only the Americans trying to flag down a taxi. You always know who the Americans are, they're looking for a car to take them.
David Rudo: Yeah, yeah. The interesting I learned, is the term Messe. That refers to ... That was the fair that took place after the Mass on Sundays. That's where the term Messe comes from.
Howard Farran: And I also want to say that I've met a lot of very successful Dentists over the years, that happened to go to Cologne, in Cologne is the largest dental meeting in the world, every other year, about 110-120,000 of us go. And they bought some product from a company, maybe it was from Turkey, or Russia, or Korea, or Israel, or Brazil, and they brought it back home, and they couldn't get it, so then they decided to be the US Distributor of this company, and now that company, being a US Distributor ... You know, because these companies, they don't have the money to go branch out to the whole world all at one time. And America is a huge market. And I just can't tell you how many Dentists I know, that were turned on to some amazing product that they couldn't even get in the United States.
And what's also amazing about that meeting, is that so many companies time their product release every two years, and the deadline for this new product is to debut at the Cologne meeting. So they can show it to 100,000 Dentists and ... Just an amazing meeting. Do you like going there?
David Rudo: As far as a meeting, you know, except for the airplane ride, it's as good as it gets. As far as a commercial meeting. I mean, I'm talking commercial. I meet people from all over the world who have been using my material. And, a number of people ... From these meetings, a number of people are doing research projects. Literally from all over. So, I interact with a lot of different people. And, when you're interacting with people, you pick up ... You learn something. You pick up different ways of seeing it. Again, I'm going to throw another quote at you. Pasteur said, no, not Pasteur. Forget which, the French writer, very well known, said, "The voyage of discovery is not going to new landscapes, but having new eyes."
So, again, it's different ways of seeing these things. Marcel Proust. So, when you listen to people, you get these new eyes. And, everybody is at that meeting.
Howard Farran: Why did you call it a commercial meeting?
David Rudo: It's strictly ... It's not academic. Everything is in the trade.
Howard Farran: Now, see, I don't know if I agree with that description. Because I almost think ... What I see at the Cologne meeting, is people that have trust, and transparency, with the owner. For instance, a lot of people are listening to this podcast and they're thinking, "Okay, is this a sales piece for Ribbond? Is Howard making money?" Did you pay me to interview you, so you could talk about Ribbond in front of 7,000 Dentists? And the bottom line is, no you didn't. You're a Dentist, and I trust you, and I believe you. And I want to hear about Ribbond and you share your message.
And when you go to Cologne, everybody wants to get their information from the company CEO, the person who made the product itself. Whereas, in America, it's a very sinister, cynical country, where they don't want to listen to the guy who owns the company. They'll say, "Well, that guy is just selling his product. I want to listen to some third person." And that third person, I don't believe, ever knows a fraction of what the owner knows. I have no problem talking to Dan Fisher about Ultradent products, and I believe what he says. I have no problem talking to Buddy Mopert, what he said about [inaudible 00:29:25]. I would rather talk to those guys than go to some Dentist who kind of pretends they know a little bit about everything, but they might not really know.
David Rudo: Know anything.
Howard Farran: I think ... When I talk to Dentist from Germany and France and Italy, they want to shake the hands of the owner of the company and ask their questions directly with the owner. So, I just don't know what's wrong with that.
David Rudo: When the owner is the developer, the inventor, the teacher ... Buddy Mopert, for example. I've watched Buddy teach people how to use his materials. And, I like Buddy. He's pretty direct. Irritates some people, but I appreciate it.
Howard Farran: I love it. I love it.
David Rudo: And ...
Howard Farran: He was actually the interview before you.
David Rudo: Yeah. And, I've watched him tell people, "The reason you're having these problems, I'm listening to you explain it, is because you haven't been using it correctly." I don't care what the material is. If you don't use it correctly, don't expect to get good results. I'd say this, for example, with fiber composites. If you don't bond those fiber material, those reinforcements, right smack up against the teeth, the resin you're using to hold it on is going to fail. That's just the physics of it. Straight fracture mechanics. And, I've had problems ... One of the problems I've had, with other companies, I'm afraid they're going to give fibers a bad name. There was Targus Vectus, for example. If they don't use it according to the principles, they're not going to get the type of result they should get.
Howard Farran: What was the story of Targus Vectus? That was the [inaudible 00:31:33] product. Why ...?
David Rudo: I believe their problem was, in their technique, they didn't have an oxygen inhibited layer within the system. In dura different layers. So there was a de-bonding. I think that was the problem. And, Ether-Clor [phonetic 00:31:56], had a ... Lost a huge amount of money on that project. One of the problems, though, is when a Dentist has problems, when a material fails, the patient is the one who suffers. So, if it's not used according to the principles of that type of material, eventually, it's going to fail. When stressed enough. Anything will work, to a certain level.
I had a fracture, a part of my bicycle. Just this past weekend. A casting fail. Because they didn't round off the sharp angles on it. And that's where the crack started from, a stress concentrator. Just like within a tooth. The way I was taught how to do amalgams, we used a preverted cone bur, and we called it a preverted cone bur, not inverted. It would put a sharp angle in the tooth. We thought we needed it for retention. And that's where the cracks started from. That sharp stress concentrator. So. Everything has to be used correctly.
Howard Farran: So, you're now on slide number 9. "Cook, Gordon Mechanisms for Stopping Cracks at a Weak Interface." A, crack approaches ...
David Rudo: That is ...
Howard Farran: Approaches a weak interface; B shows interface ahead of main crack, and C, a t-shaped crack stopper. Talk about that slide.
David Rudo: Take that slide, and look at the next one also. The next slide is safe [inaudible 00:33:53] glass. Which is the weak interface. The crack goes through the outer glass layer. It gets to the resin membrane, which is a weak interface. It's blunted. And stops. That is the basis of a composite material. In the enamel, you have the protein matrix around each enamel prism. The crack is stopped at that protein matrix. And that's why you see the craze lines in the enamel. Perfect example of this.
Now, people or other manufacturers will say they have a stronger bond. Their material bonds, it's stronger, to the resin. Well, if it's too strong, you don't have the weak interface. And the crack goes right through. It's not stopped. So, that's the key to a composite. In a dental composite, the crack gets to a particle, dental composites are particle composites. The crack gets to the weak interface of the particle, and it travels around that particle. So, that's the essence to a composite material.
Howard Farran: Now, is there any analogy of the same industry ... A different industry, like, concrete people putting rebar into the concrete.
David Rudo: I think with rebar, I think what they're just trying to do is just get a framework within it. I'm really not sure. But they're ... I'm not sure. But I think they're basically looking for something to hold it together.
Howard Farran: Well, because your next slide, slide number 11, you're showing laminated safety glass damaged. And what is the point in that slide?
David Rudo: The laminated safety glass is that weak interface. The weak interface between the glass and the resin membrane in there. And the crack is blunted there. It doesn't go all the way through. If that wasn't in there, the crack would just propagate right through the glass.
Howard Farran: That's a very interesting slide. So, slide number 12. "Fracture Mechanics" Griffith cracking ...
David Rudo: Oh, wait a second, wait a second. We have a slide 10 showing a fiber stopping it.
Howard Farran: Right.
David Rudo: When the crack gets to the fiber.
Howard Farran: Right.
David Rudo: That again is from my mentor, Vistasp Karbhari, the crack ... It shows a series of pictures, of a fiber with resin around it. A fiber sitting in resin. In the first picture, the crack starts ... Well, it just shows the fiber sitting in the resin. Next picture, it shows a crack opening in the resin. In the next picture, it shows the weak interface between the fiber and the resin, and at the tip of the crack, which is called the "process zone," that's where the stresses are the greatest, in front of a crack. You've seen the classic picture of a crack propagation. And the stresses are greatest just in front of the crack. So, the fiber delaminates circumferentially. Then, it continues the circumferential delamination continues until it gets to a weak point on the fiber and the fiber breaks. The next picture, the broken fiber pulls out.
And that's what happens with a fiber composite.
Now, my next slide, I think 12, is a slide from JE Gordon dealing with a Griffith crack propagation. What that shows ... It takes a lot of energy to stop a crack. It takes energy, which is the ability to do work, to start the crack. Once the crack gets to the critical length for that material, it just explodes. That's what happens when you blow up a balloon and puncture it. It literally explodes, but you have to put all that work into it, before the crack opens. When you flex an acrylic rod, you are putting a lot of work into it. You put a scratch on the tensile side of that acrylic rod, that's the stress concentrator, and it explodes and breaks. I use that to demonstrate strain energy. The energy it takes to open up a crack.
So, that is a classic Griffith ... A description of Griffith's principle, and Gordon described it as cleanly as possible.
What's next?
Howard Farran: "Glass Fiber Breaking and Pull Out." Slide number 13.
David Rudo: Okay, so, correct. That was from a study done way, way, way back when I got started at SUNY, SUNY Buffalo. Brendan Grofferty [phonetic 00:40:06], I think. He's from Ireland. And it shows a crack getting to the fibers, and then the pull ... The brittle glass is fractured and pulled out. That's that picture.
Howard Farran: Very nice. And then slide 14.
David Rudo: That shows the Ribbond-Lena weave [phonetic 00:40:31]. And also the Ribbond Triaxial. The Ribbond triaxial is our greatest load baring material. It doesn't adapt as well as a Ribbond-Lena weave. But for, for load carrying situations like in edentulous areas, in bridges, when you have intracoronal preparations or crowns, that's our material of choice for that. But our Lena weave shows ... It's hard to describe the Lena weave to somebody. You have an axial and tranverse fibers. I didn't invent ... I invented some questions, and the weaver told me I wanted a Lena weave. When I developed Ribbond, I wanted a weave that would be open and lace-like, so it could follow the contours of the teeth, but once it was in position, it would be locked. And that's the Lena weave. It's an ancient, ancient, ancient weave.
With that, when ...
Howard Farran: How ancient? The Greeks? Or the Egyptians? Or the Chinese?
David Rudo: Who knows?
Howard Farran: Who knows?
David Rudo: I don't know. I would say not that ancient. When were looms invented? Probably back then. But, it's originally to make decorative, lace-like structures. Within a year I developed this stuff, and got a patent. I wrote away to 6 or 7 composite research centers. Somebody replied, who became my mentor, Vistasp Karbhari. Years later, I asked him why he replied. He said, "With that Lena weave, it is a constant series of crack-stoppers, which makes for a very, very tough material. At each one of these nodal intersections, where the lengthwise and the transverse fibers are twisted, literally, twisted together, the crack traveling along that axial fiber is arrested." So, again, looking at the fracture mechanic slide, you have to put new energy in it to start a new crack. So, it's constantly eating energy.
It's like if you're splitting wood. Say it's a straight-grain wood, and you drive a wedge in there, it just splits. And you get to a knot. It's all twisty and turny, you can't propagate the crack through there. It's constantly taking energy. So, that's the Lena weave, which makes it very, very effective. And it also holds it together when you adapt it to the tooth.
So, I think that describes that slide. Also, we consider ourselves to be specialists in designing ... I consider myself to be a specialist in designing the fiber layout, we call fiber architecture. Our Ribbond Ultra is our third generation of Lena weaves. By changing ...
Howard Farran: Very ...
David Rudo: Yeah. So, it's a much higher, modulous and load baring material than our earlier ones.
Howard Farran: Now, on your website, Ribbond.com, R-I-B-B-O-N-D dot com. Do you have lectures on this? On the website? Do you have ... Is there any information on there?
David Rudo: There's a bibliography of articles.
Howard Farran: So, just basically articles.
David Rudo: Yeah.
Howard Farran: Do you have a lecture on Ribbond? Like an hour long lecture on the use of Ribbond?
David Rudo: When I give presentations, depending on the audience ...
Howard Farran: But I mean over the years, you never got one, like say a clinical professor at a meeting, you know, a power point, or a video?
David Rudo: I have power point presentations, and it depends on what the interest of the group is, if I'd be showing something to Prosthodontists, it would be different than what I would be showing to ... Well, an example, the Academy of Biomimetic Dentistry.
Howard Farran: Explain what that is to our listeners.
David Rudo: The Academy of Biomimetic Dentistry is ... Let me ask you, do you know of Graeme Milicich? Have you ever met Graeme ...
Howard Farran: Oh my gosh, out of New Zealand?
David Rudo: Yeah.
Howard Farran: I love that guy. Whenever I think of New Zealand, that's all I think about it Graeme Milicich.
David Rudo: He is the master of doing this type of work, that the Academy of Biomimetic Dentistry is interested in.
Howard Farran: And minimally invasive dentistry.
David Rudo: Well, minimally invasive, and the best description of minimally invasive dentistry came from a Greek cosmostralegist who said, "Minimally invasive dentistry is not removing less tooth, but keeping more tooth." It's a different way of saying the same thing.
Howard Farran: Explain why you find that phenomenal. Minimally invasive dentistry is about keeping more tooth, not removing less tooth.
David Rudo: Okay. People come in with a shell of a tooth. You don't want to destroy that shell. You want to keep that shell, that enamel shell, because that will let you rebuild the tooth. Graeme Milicich is going to present to us in Philadelphia in October. A full day presentation. I think you would find it to be absolutely ... If you can get there, it would be absolutely fascinating.
Howard Farran: Well, why don't you send ... Do you email him? Or do you talk to him on the phone?
David Rudo: I email him.
Howard Farran: Well, why don't you email him, and cc me Howard@dentaltown.com and talk about this and maybe that's a possibility.
David Rudo: I'll do that.
Howard Farran: Okay.
David Rudo: He's going to be there, and a guy name Inacochi [phonetic 00:47:21], from Japan. Inacochi, who was the one who was with Fusayama ... Inacochi is the master of carries detection. Differentiating infected from affected dentin. So, if it's just affected, you leave it. Again, I'm saying, you're not removing that. You're keeping more tooth. Just because it's partially demoralized ... Demoralized. Demineralized, you don't get rid of it.
Howard Farran: And that's why carries indicator is kind of troublesome, because if you keep using carries indicator, it's going to stain affected dentin, right? And you're going to keep removing stuff that doesn't need to be removed. Would you agree with that statement?
David Rudo: It's ... I can't say, because it's not my expertise. I know a little, but not enough. I know enough to make a fool of myself. Don't get out of your field of expertise, try to be an authority in what's not your field of expertise is my ... I'll play it safe.
But anyway, I'll send an email to Graeme. I knew you had to know him. But he, he'll take one wall of a tooth, and you'll see a slide representation of that, and how he'll rebuild that tooth. And he's had amazing results. He has a good functioning brain.
Howard Farran: Oh, he's so smart. And you know another one down under, there's three legends, I think, of all the time down there. There's also Geoffrey Knight ...
David Rudo: Yeah.
Howard Farran: In Melbourne. And there's [inaudible 00:49:08] in Adalaide. Are you familiar with [inaudible 00:49:12]?
David Rudo: No, no. I don't know ...
Howard Farran: In fact, he got the largest grant ever from Colgate. You know, Colgate is really the biggest toothpaste company in the world. You know how American's say Kleenex, even though they're using a tissue, or they say, "Give me some Cola."
David Rudo: Oh yeah, the brand name.
Howard Farran: Yeah, in many countries around the world, the name for toothpaste is Colgate. They'll just say, "Put some Colgate on that." Even though they're using another brand. And he got the largest Colgate grant. He's a Vietnamese guy who ended up in Adalaide. I mean, there's just so many sharp minds down there.
David Rudo: Oh yeah. Well, you know, it's funny, with Australia. I remember the time of the Monica Lewinsky incident. There was a letter to the Editor of the New York Times taken from the Sydney, Australia newspaper, how lucky they were that they got the convicts rather than the Puritans.
Howard Farran: Ha, that was funny. When anybody says "Monica Lewinsky" the only thing I think of is right after that broke, I was lecturing in Warsaw, Poland, and the taxi driver picked me up, he was so proud that Monica was Polish. He said, "Your President could have had any woman in the world, and he wanted a Polish girl named Lewinsky." And I thought it was just this cab driver. But then I heard it like, five more times over the course of the week I was in Warsaw, so I thought ...
David Rudo: You were recognized.
Howard Farran: I thought that was just so hilarious. So, slide number 16. "Simulated Ribbond Molar Reconstruction Circumferential Fiber Replacement"
David Rudo: That would be an example of what Graeme Milicich would do. It shows ... I took a dentiform tooth, made a monster class one, kept four [inaudible 00:51:02] and laid it circumferentially around those walls, close smack up against the walls. People have done this with a half a millimeter of enamel and there were no craze lines. Again, the closer it is, you're making literally a laminated structure out of that tooth. You've seen prelimeralization shrinkage causing craze lines in the enamel. With this, you have next to no resin to shrink. So, you lay it in there, smack up against the tooth. You can ... There's different techniques, there's different principles, but that's the general idea. This greatly, damn near eliminates C-factor.
I'm going to be involved ... I was in Tokyo for a pilot study in November, dealing with OCT, using OCT, Optical Coherence Tomography, to watch gap formations in restorations when you put in a highly shrinking composite resin and prelimerize it. What this showed, when you lay the Ribbond smack up against the pulpal floor and prelimerize that, and then you put your bulk fill composite over that, the gap formed between the Ribbond layer and the bulk composite, safe ... In a safe area. Without the Ribbond in there, the gap forms between the tooth and the resin. That's an ... And we watched this in real time.
The person who was behind that study is an Iranian, was studying and working in Tokyo Medical and Dental for 12 years. Just moved to University of Washington here in Seattle, so I'm working with him now. I couldn't have been more lucky.
Howard Farran: That is amazing.
David Rudo: The fickled finger of fate.
Howard Farran: You should get them to post cases on Dental Town on this. You should get Graeme Milicich and these guys to post cases because on Dental Town, you know how there's the message boards, there's on-line CE, there's classified ads ...
David Rudo: Yeah, yeah.
Howard Farran: But, and the magazine, of course, digital, but the cases are actually, you know, we watch what they do. What do they do. And we have today's active cases, and that's just a hot feature. I mean, if you could get these guys, a Graeme Milicich and all your key opinion leaders to post cases, you would really spread your life's work to far more Dentists around the world.
David Rudo: I agree with you. The funny thing is, to change a culture is difficult. You've seen that over and over again. The most resistant place to changing a culture is the Dental Schools. Because the faculty is invested in the way they do stuff. And ...
Howard Farran: Because the guys teaching amalgams have jobs, and they don't want to lose their jobs so some other guy can come in and teach composites, or ...?
David Rudo: They don't want to change ... Yeah, that's their turf.
Howard Farran: Right.
David Rudo: That's what they know. And, I finally figured out how to get some Dentists to change. Because once they know about this, it's hard, in good conscience, to continue doing things the traditional way. What I finally figured out, is when these Dentists treat their friends and family, now that they know better, they should be using these techniques.
Howard Farran: And that's exactly what I'm trying to do with podcasts because, the one thing I've seen the most successful Dentists do, the number one trait, they're always humble. They're humble to their staff, they're humble ... They're always listeners. They're listening to their staff. They don't have to pay a $50,000 Consultant to come in and listen to staff and tell egomaniac ... They're listening to their staff. They're listening to their patients. They're listening, listening, listening. And those are the same ones that take ... About 250 to 300 hours of continuing education a year.
So, when a lot of people throw Dental Schools under a bus, I mean, I think it's amazing they can take a kid off the street and four years later, he's licensed to do root canals, and bolas, and ... But I look at the Dental School graduation and if nothing changes, you still have got to be taking a ton of CE for the rest of your life and I'm hoping this podcast makes it easier, faster, lower in cost, higher in quality. Because they are multi-tasking on a commute to work, or on their bicycle, or on the treadmill, and here they are, in the old day, to listen to you, they'd have to wait until their annual meeting, or something, and close down their office, then go sit there all day in a convention. And now they can just get an hour here, and hour there, and I think that's why these podcasts are huge, because it's just a really low cost, high quality form of continuing education.
David Rudo: Well, it may not be the final education for them, but it's opening their eyes. It's making them aware. And those people who are curious will then pursue it. But you have to be aware first. And I think that's a real benefit.
Howard Farran: Well, there's ... You don't have anything on Dental Town, and there's a, there's 200,000 registered Dentists on that site. So, try to get some of your key opinion leaders to get something up there so they can see more there.
David Rudo: My son handles the marketing part. I don't do the marketing. And he's had ongoing battles with some of the other manufacturers. But, I'm just ... It's not my gig to do the marketing, but to get people to participate. If I can get the forum open, open the door, and Dentists like to show what they can do. They like to share what they can do. They like to tell their buddies. We have study clubs. They like to participate. The next slide, "Crack Bridging," again, if you look underneath almost any old amalgam, you'll see cracks in the pulpal floor. That's from, a lot of it is the placant effect, when there's old amalgams there, and they bang down on the amalgam, the vertical force is transferred and translated into a lateral force. And it opens cracks. And we bridge the cracks. These are supported by studies.
It was funny, Selma Bali [phonetic 00:58:25], a woman, a female from Turkey, did most of the, a lot of the original research on Ribbond. And one of them was dealing with bridging cracks, and I put her ... I had a very fortunate experience. She was in town, in Vancouver, BC, for the Academy of ... International Association of Dental Research. She was there the same time my mentor, Vistasp Karbhari was coming through, going to Vancouver Island, to watch the whales with his wife. And I put her together with Karbhari. And they coauthored some articles. So, you don't get luckier than that.
Howard Farran: Well, we are over time. We are at an hour and one minute. So, we're going to ... I'm in overtime. But I want to tell the Townies that if you download the Dental Town app, onto your smartphone, you can go to itunes, or the google app play, you just search, put in the keyword Ribbond, I mean, my God, there are so many threads on this app. I'm just scrolling down, they go forever. So, you have a tremendous amount of threads that ... I mean, there's several in the year 2015, several more are 2014, 2013, 12 ... I mean, it just goes on for years. I've been scrolling down, I'm down to 2009 ... Is there any before, I mean, it just goes forever. So, this has been a major product for a long time. And I just want to tell you that I'm a big fan of yours. I think we've spoken dozens of times at conventions over the years ...
David Rudo: Yeah.
Howard Farran: And I just want to say, David, congratulations on just an amazing career. I can't believe you got out of Dental School in '61. I was born in '62. I just knew you [crosstalk 01:00:20] guy, you're a role model ... You're the healthiest guy at every Dental convention, you ride your bike, you work out clean, you eat clean, you're just a hell of a guy. And I want to profoundly thank you for all you've done for Dentistry and for spending an hour with me today.
David Rudo: Howard, I appreciate your interest, and what you're doing in getting the word out and getting people educated. Opening their eyes, at least. And there is no other real forum. I know of no forum. So, even in research Journals, there's no Letter to the Editor, if something is not correct. So, yours is the forum.
Howard Farran: Yeah, we talk about every subject from A to Z. So, it's just an amazing ... But we're out of time, buddy, so I need to cut you loose. It's an hour and three minutes. That's my brand's, an hour, thank you for your time. And have a rocking hot day.
David Rudo: You too.
Howard Farran: Thanks, bye.
David Rudo: Bye.