Artificial Intelligence & Endodontic Concepts Update on AI in Dentistry and Q&A

This show opens with Ruddle and Lisette revealing some summer plans… specifically, some special summer plans for The Ruddle Show! After that, Ruddle and Lisette resume discussions on a few exciting and expanding applications of AI in dentistry. Then, in a Q&A, some important endo concepts, like rotary first and deep shape, are covered. Finally, Season 7 concludes with a new Close, “Favorite Places.” Enjoy getting a fresh perspective of one of our favorite, secret Santa Barbara spots that is not featured in the tour books.

Show Content & Timecodes

00:55 - INTRO: Summer Plans
06:47 - SEGMENT 1: Artificial Intelligence in Dentistry
21:23 - SEGMENT 2: Q&A – Endodontic Concepts
41:16 - CLOSE: Favorite Places – Top of a Parking Garage

Extra content referenced within show:

  • Practical Clinical Courses:
  • Academy of Microscope Enhanced Dentistry (AMED):
  • Western Society of Periodontology (WSP):
  • Elani HW, Batista AFM, Thomson WM, et al: Predictors of Tooth Loss: A Machine Learning Approach, Plos One, 18 June 2021,
  • Machine Learning Predicts Who Is Most at Risk of Tooth Loss, Dentistry Today, 24 June 2021,
  • Low SB, Chang P: A Roadmap to Success in Managing Early to Severe Peri-Implantitis, Dentistry Today, 5 May 2022,
  • University of Michigan: AI helps predict treatment outcomes for patients with diseased dental implants, ScienceDaily 12 May 2021,
  • Ruddle Article on ProTaper Ultimate (see downloadable PDF below)
  • More Content on ProTaper Ultimate SLIDER and the ‘Rotary-First’ Concept:
  • Advanced Endodontics (Ruddle’s Educational Website):
  • Advanced Endodontics Just-In-Time® Video Library:

  • Select PDF content displayed below. See Ruddle's complete library of downloadable PDF content at

    See also Ruddle's complete Just-In-Time® Video Library at

    Downloadable PDFs & Related Materials

    Ruddle Article
    "The Ultimate Shaping System: An Opening for 3D Cleaning & Filling Root Canals"
    May 2022

    New and potentially disruptive technologies come to market each year, proclaiming to improve on what came before. Many of these newcomers have virtually no evidence-based research to support claims of better, easier, or faster...

    Ruddle/West/Machtou Article
    "Deep Shape in Endodontics: Significance, Rationale and Benefit"
    Feb 2022

    The goal of endodontic treatment is to prevent or cure, when present, Lesions of Endodontic Origin, at times referred to as apical periodontitis. The role of bacteria in the pathogenesis of endodontic disease is well established, and therefore, it is critical to eradicate these pathogens by employing the highest level of presently developed standards...

    Ruddle Article
    “Current Concepts for Preparing the RCS”
    Jan 2001

    Successful endodontic treatment requires that the clinician predictably shape root canals for three-dimensional obturation. In this article, the guidelines for successful access and the concepts and strategies for canal preparation will be discussed...

    Ruddle Editorial
    “Focus On: Minimally Invasive Endodontics”
    Mar 2014

    Clifford J. Ruddle, DDS, discusses predictably successful endodontics in the context of preserving healthy tooth stuctures...

    Ruddle Technique Card
    "ProTaper Ultimate"
    Feb 2022

    Ruddle Shaping & Finishing Technique Card featuring ProTaper Ultimate

    Related Polls

    This transcript is made available by The Ruddle Show in an effort to share opinions and information, and as an added service. Since all show text has been transcribed by a third party, grammatical errors and/or misspellings may occur. As such, we encourage you to listen/watch the show whenever possible and use the transcript for your own general, personal information. Any reproduction of show content (visual, audio or written) is strictly forbidden.



    …It’s 20 at the tip. A D-1 it would at 7, 27. A D-2 it would be 34…

    [music playing]

    INTRO: Summer Plans


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


    Good morning. How are you?


    Great; how are you?


    I’m doing great. And I’m curious what all our viewers are going to be doing this summer. There must be a lot of plans out there.


    Yes, well we are shooting today our last show of Season 7.


    Yay. Oh, oh, the last show.


    It seems like it went really fast. We have Season 8 planned for the fall, and we’ll start shooting that later in the summer. We do, however, have some ideas in the works for the summer for The Ruddle Show, and we still plan to bring you some content, some special content, but in a little different format. But first, some really big news. And this is big news because you are resuming a travel schedule related to lectures and workshops. And you and Mom, so everyone knows, have been at home for the last two years basically because of the pandemic.

    Of course, you’ve still been doing The Ruddle Show and some Zoom lectures and stuff like that, but this is exciting. Where are you going and what are you doing there?


    July 29, 30, we going to – well, we’re going to still go to Utah. I think it’s Gordon Christensen. Is that his name, Gordon Christensen? Yeah, we’re going to Gordon Christensen. Everybody around the world knows Gordon, and he gives the Practical Clinical Courses, PCC, and it’s his hands-on courses, so it’s two days. And one day didactic, and then one day you get to pick up all the tools and we’re going to look at your shapes. We’re going to see how you pack. And you’re going to do start to finish endodontics. So, that’s exciting.

    I heard the course is sold out, but I’m telling you anyway because people always change their schedules and things are dynamic and volatile and moving, so have that on your radar if you’re in Utah and you’re in the Grand Tetons and you want to come out to the mountains, the state parks, and you want to learn endo, I’ll be there. And then the other course will be August. It will be August 16 maybe.


    I think it’s September.






    September 16, yeah. And that’s in San Diego, and that’s a combined meeting. That’s the Western Society of Periodontology along with the Academy of Microscope Enhanced Dentistry. And they’re coming together. Actually the third branch is the Hygiene, the National Hygiene Meeting is also part of this. So, it’s three big entities coming together under one roof, and I’ll be talking about microscopes for two hours.

    So, I’ll be talking about my deficiencies, my adoption working to get proficient and then the documentation and teaching and then how I integrate it and do some difficult cases. So, I’ll show the importance of magnification lighting.


    Okay, well that sounds exciting.


    I am excited.


    So, back to some of The Ruddle Show ideas, one thing we thought we might do is a start to finish Endodontics week, and it’s how that would work is that each day we would feature a specific aspect of endodontics. So, like maybe the first day would be diagnosis. And what we would do is we would go back through segments we had shot on The Ruddle Show and compile in a large show all the segments on diagnosis, and then maybe we would also offer some additional commentary.


    We’d want to spice it up, right?


    Yeah. And then maybe next day we’d do abscess until we go all the way through start to finish endodontics. So, that is one idea we had, and hopefully, we can do it. We’re still trying to work out all the details on it. But then, what else? Maybe a podcast or two?


    Well, you have this son that I call The Shooter, but he does have a name. His name is Isaac. He’s the youngest member of our Ruddle Show team, and to tell the audience something maybe you don’t know, but Lisette and I, we meet regularly on non-show days to work on shows. And so, we Zoom, and Isaac puts the meeting together and I join the Zoom call. And then Lisette kind of like – and I start creating, creative thinking, and we start thinking about possibilities.

    And anyway, he’s been watching this for some time, and he’s noticed that it’s quite interesting because we go in a lot of different areas, and it’s very creative. And he said, “Well why don’t we just have a less formal session and maybe we could do some podcasts and you guys could just drill down and go all over the place.” And he thought it would be very fun. So, that got my attention because that’s something new, and I always like to do new things and keep stimulating myself so I can be the best that you guys expect me to be.


    Yeah, we’ve actually had some requests from some younger clinicians who really like the podcast format, that maybe we would consider doing a podcast. So, Dr. Randy Cross, if you’re watching this, we have some podcasts in the works. So, then we also might do a special report or two, we’ll see, so we definitely will be, you know, present and we plan to bring you some special content. We’re still just trying to work out all the details of how – of what we’re going to do.


    We might even change our set I heard.




    We have three sets, and the set that they see less frequently, Set C, is going to probably turn into something that’s more where we can do some of these things Isaac has seen that he likes. And incidentally, lots of young dentists are permanently wearing their buds and they’re permanently on bicycles and they’re running on treadmills, and anyway, they could watch the podcast.


    Okay, so watch for –


    Or listen to the podcast.


    – what’s coming, yeah. Well we’re going to probably do a video podcast so they’ll be like video and sound.




    Maybe we’ll just only do video. Okay, well we have a great show for you today, and let’s get going on it.

    SEGMENT 1: Artificial Intelligence in Dentistry


    All right, well today we wanted to devote another segment to discussing artificial intelligence and its applications in dentistry. So, just for clarity and so we’re all on the same page, AI refers to machine or software that can mimic human intelligence. And the idea is that by analyzing a large body of data and employing certain algorithms that AI will be able to predict outcomes and problem solve.

    So, previously on our show we talked about how AI could be used for diagnostics, like detecting root fractures and caries. Today we wanted to talk about how AI could be utilized to predict outcomes like who is most at risk for tooth loss or how people will respond for treatment for periimplantitis, so we’re going to talk about it in that sense. So, to start, why don’t you tell us about the Harvard study where AI was used to predict who is most at risk for tooth loss.


    Very good. Harvard. in concert with the University of Watauga, New Zealand and Sau Paulo, they wanted to find out just what Lisette said, what is this patient’s potential risk for tooth loss? You might see them at any time in their life, so you might want to know that. So, they did five algorithms, and the algorithms were pretty interesting because normally we just see people chairside and we do an exam.

    So, the question was how does the dental exam compare to these algorithms, and the algorithms were on the medical conditions. They wanted to know more about the medical. We all chairside have a medical history and we can do the oral exam and we have radiographs, so that’s not real new, but what was new is the socioeconomic. And they kind of looked at things in terms of just when I classify these things, just think of low, medium and high.

    But really, your education might dictate the kind of job you have, so education, job. The job might dictate how much money you have to spend, especially if dentistry is considered elective. Gender and race plays a role, and then finally, people that went on the internet. So, they looked at all these variables, medical report, your medical history. They looked at socioeconomic, and they looked at dental. And they found out that those three things with their algorithms were far more superior. They were far superior to prognosticating future tooth loss than just the dental exam and medical history alone.


    Well, that is interesting. And it makes me think a little bit of what we’ve gone through with the pandemic in the last couple years because I personally, and I am not – I’m a little embarrassed to say this, but I didn’t realize how big a role socioeconomic factors play in a person’s overall health. And we saw early on in COVID that deaths were disproportionate depending on race, wealth, the region of the country a person lived, education, and it seemed that poor and less educated individuals as a whole, the group as a whole, tended to be a little less healthy, maybe more overweight.

    And whether this is because of diet, living in an inner city where you’re breathing more polluted air, what else? They were maybe – had less access to healthcare even or maybe they even smoked more. So, it seems that they also tended to work more in the essential businesses exposing them more to COVID, so it really definitely makes sense that socioeconomic factors would also play a big role in a person’s dental health.


    Yeah, I saw this personally. You were a little kid at the time. I mean you were like, well I don’t know, you can’t see back here, but I don’t know, she was probably, I don’t know, three or four years old, but I was in Boston, I was in grad school, and it was critical that I have some curriculum outside of Harvard. I needed to work to pay my way through. Phyllis always said that she’d help me with dental school, but when I went to grad school. I was on my own.

    So, I had Phyllis and two little kids. And so, I worked in Mattapan. Mattapan is a suburb of Boston’s inner city. And it’s a very poor area. It’s predominantly people of color, and I noticed when I went and worked in the clinic, I had been at Harvard and I was seeing patients, and they had crowns and castings and amalgams, and their mouths were always pretty good, but they had a chief complaint. But when I was at Mattapan, I saw no tooth, blown out teeth, I saw hopeless teeth, I saw hopeless perio, I saw a lot of people in severe pain because caries’ exposure.

    So, when we did do endodontics, we were going through carious lesions right into the pulp, and I had a rude awakening when I came to Santa Barbara because every access was through heavily restored teeth. It seemed like I had to drill 10 millimeters through occlusal gold just to find the roof of the pulp chamber. So, yeah, that’s an example, and then, of course, if you looked at the history of the people that are working with you, they fall right back into your education, they fall right back into well what’s your job, what’s your income, and what’s your gender and race, and those kinds of things.

    So, I really saw first-hand for two years. It was a great job and I learned a lot and I treated some wonderful, wonderful people.


    Okay, so if AI can predict who is at most risk for tooth loss, how is this helpful?


    Well, if you could prognosticate tooth loss with these algorithms, then you might, if they’re small patients, which I saw in the Mattapan Clinic, cause we had one of every specialty. At that time we had seven different specialists in that clinic. Well the pedodontist could do resin on the occlusal surfaces, they could use these different things to prevent caries, so prevention was very big in the young patients.

    And then in the older patients the main thing is a triage, you know, like take care of pain, get them out of pain, and then stabilize what is left. That means get rid of the losers and clean up their mouths, and then maintenance. And maybe they can have a few teeth left that can hold a partial denture. But we’re not going to be doing implants and sophisticated restorative dentistry on these patients.


    Okay, yeah, I mean keeping your teeth is definitely a high priority, and it definitely seems like in our society, there’s more and more importance placed all the time on having nice teeth. And you might even remember on our last show we talked about how the rules are starting to change in hockey to actually benefit a player’s dental health. So, definitely there is this trend to trying to save our teeth.


    Are you saying there should have been an algorithm that these three universities put together and qualify were they or were they not hockey players?


    That wasn’t one of the criteria.


    That wasn’t.


    But it’s understandable why researchers today are really motivated to develop algorithms to find out who in the general population is most at risk for tooth loss and maybe prevent it. So, do you have any closing remarks before we move on to the next topic?


    Yeah, I mean tooth loss, especially when you’re working in the inner city, it can be catastrophic physically and emotionally. And physically, that could be can’t eat or chew so well, maybe your speech, there’s a lisp or you hear wind between teeth, and so this makes people insecure so their interpersonal relationships are a little less than they could be optimally, and they’re less secure. So, if we can stabilize people and move them towards health, that’s going to help us in the long term help people keep all the teeth they can.


    Okay, well we learned about this study from a Dentistry Today news article, but if you’re interested in reading the whole Harvard study we’ll try to have a link to it in our Show Notes, or even just a reference. But now let’s go on to the next topic, and that is how another recent study out of the University of Michigan where AI was utilized to predict treatment outcomes for patients with diseased dental implants. Why don’t you tell us about this study?


    Well, maybe I should set the stage a little bit first. First of all, internationally, we’re approaching $6 billion, just the implant game. I didn’t talk about the casting on top of the implant or the bone augmentation. I’m talking about just fixtures, about $6 billion. And in the United States, it’s $2 billion. So, what’s the point? Well what if you knew that 25 percent of all implants develop periimplantitis. In fact, that’s not so uncommon. And it’s not so unusual to see somebody who’s had an implant and a year later there’s an infrabony pocket, maybe two, three, four wall.

    So, the point is how can you prognosticate this? So, what was pretty interesting is the University of Michigan, they were able to write programs and algorithms to develop who would respond best post-surgery. So, first you’d want to get the implant, and we’d want to emphasize recalls and maintenance, but when they see it, then they would typically, they might try antibiotics for a round or two, but usually they get flap procedures, pull the flap back and try to clean out the infrabony pocket and use reparative and regenerative materials, put the flap back and suture and then the question is how many of these cases that had surgery can go on and improve or deteriorate further?

    So, they were able to take crevicular fluid out of a sulcus and you can do immunoassays on this fluid, and immune cells that were able to fight micro organisms were superior to immune cells that help in tissue repair and regeneration. So, that really threw them by – that caught them off guard because they were thinking regeneration and repair, that’s what you need after you’ve done the surgery around the peri-implantitis problem. But they found out it was much more – it was much better to control pathogens.


    Well, it is surprising that roughly one quarter of implant patients will develop periimplantitis, and in the article, the researchers said a large part of their motivation to develop these algorithms is because of this emerging endemic of periimplantitis that is really compromising the long-term success of implant dentistry. So, knowing the high incidents of periimplantitis and learning that better regenerative outcomes occur in patients that have more immune cells for microbial control, how does this new information serve to guide a patient’s treatment?


    Well, I kind of answered it, but I can go a little deeper. If you can take crevicular fluid and you can do a chemical assay on it, you can look for t-cells, macropsias, osteoblasts, and all these can be turned on, turned off, to different levels to balance repair, but mainly killing microorganisms. In fact, people that have some medical conditions like arthritis or diabetes, it would be wonderful if you could know before you ever put the implant in is this a good candidate based on machine learning and having huge databases.

    You could start to tell people chairside on the consultation, you are – well, you’d have to have a consultation, get the report back, but you could tell people who might be good candidates and who is not. So, long term, in some hope I’ll say this just quickly, if I have time.




    Sam Lowe from, he’s a great periodontist and he’s in Florida, he wrote an article in Dentistry Today, he was the cover guy, and what he showed was that, you know, usually they reflected on the periimplantitis problem and they would curette the diseased tissue out, granulation tissue, we all know that, but the problems have been how do you create a good site environment for healing? And of course, traditionally we haven’t had lasers, so they were scraping implants and scratching them. They were ruining the titanium surface.

    Anyway, he found out that this ERCRYSSG laser by Biolase, it has an affinity to not damage the implant. The laser rays can be absorbed into the implant, it can give you completely squeaky clean surfaces, and he found out that he was able to see decontamination of the implant. They were able to see that there were complete areas where tissue reattached to the implant, and they were finding that they got much better healing. So, it looks like we’ve talked about lasers a little bit; it looks like lasers have a role in this periimplantitis treatment.


    Okay, well that sounds actually kind of promising that there might actually be a little bit of a solution that can come from lasers as well as just knowing what kind of immune cells a person has and what their ratio of wound healing cells are to microbial control cells, you know.




    Okay, so that’s some interesting information. If you’re interested in reading the study from the University of Michigan, we’ll try to have a link or a reference in our Show Notes. So, that’s all we have for today.


    When are you guys coming?


    Last time we talked about AI or we’ve mentioned it in a few shows, but we talked about it in terms of diagnostics. Today we talked about predicting outcomes. Next time we want to talk about how you can actually incorporate AI into your daily practice.


    Oh yeah.


    So, we already have that planned for next season.


    Maybe we’ll be in training this summer so that when we come back in the fall we can show our hand.


    Yes, well thank you for explaining those studies and for the great information.

    SEGMENT 2: Q&A – Endodontic Concepts


    Okay, so here I am at the board joining my dad because we thought we would close out this season with a Q&A. So, today the Q&A is going to revolve around endodontic concepts, but before we start, it was pointed out to us by one of our viewers that you made an egregious error on one of the earlier shows this season. We all missed it, but Dr. V.K. Karthikeyan noticed it. So, why don’t you clear that up for us all right now?


    Thanks, BK. Normally, when you lecture live, there’s a handout there, and there’s like I’m having a problem with something, so you could just identify it. But in this case, there was nobody here except the set people, so I’ll identify the problem right now. But if you want to know what we were talking about, we were in the segment of ledge management. And we were talking about how to buff out the ledge. And I was talking about a 10 file.

    And the egregious error is I misidentified the cross sectional diameters as 0, 1, 2, 3, 4, 5 millimeters, working up the file, in the file, D0, 1, 2, 3, 4, 5. So, the diameters are there. I guess some of you probably would really benefit if I said millimeters, but anyway, that is 10, 12, 14, 16, 18. At D5, it’s a 20.


    So, you do know it.


    I do know it.




    I just – well I started off correctly, and then I cleared the board and then I got off.


    Okay. All right. So, here –


    Thanks, V.K.


    Now we’re going on to endodontic concepts. So, the first question is this. I hear you often speak of root-appropriate shapes. How exactly do you define a root-appropriate shape?


    Well, that’s a good question, and so often misunderstood. And “root-appropriate” sounds like it’s totally subjective. Let’s put some ideas around it, and then it will make more sense. ProTaper was the first system in the world. It was launched in 2001, and one of the IP’s that did expire 20 years later was regressive tapers. We were the only file, the first file and the only file in the world, that didn’t have from the tip of the file as you move up that instrument, all the files had fixed tapers. They were 2 percent, 4 percent, 6 percent, so they were getting bigger every time you moved up the file 1 millimeter, a little bit like that last drawing.

    With ProTaper we decided, since as you get to the bigger finishing files, they would be enormous at D16, we decided to have regressive tapers. So, the file came to market in 2001, and we could have tapers of 7 percent, 8 percent, and we could have tapers of 9 percent. The secret is you can’t run that taper out over the whole length of the file. So, our concept was, if we just look at a real simple tooth, and we divide it into thirds, so we have coronal one-third, middle one-third, apical one-third, we wanted to have a zone in this region, pretty clever, huh?

    We wanted to have a zone where the file, instead of getting bigger and bigger and bigger, it would be getting smaller at a smaller rate. We still then wanted the classic deep shape. So, what makes a root appropriate shape then? For me, it’s to have deep shape in this apical one-third, and then have a smaller body to respect minimally invasive endodontics and the restorative effort that lies ahead.




    So, that’s a root-appropriate shape.


    So –


    And incidentally, we’re the only system still today that offers tapers of 7, 8 and 9 percent on example, the F1, the F2 and the F3.


    All right. So, the second question. Is MIE, minimally invasive endodontics, is MIE and root-appropriate shaping basically the same thing in theory?


    Yes and no. Everybody likes to think a root-appropriate shape is minimally invasive. But the problem is most people today in the world of minimally invasive endodontics, they’re using instruments that are like 15/04 or perhaps they might be using a 20/02, more or less the same file. For novices out there, don’t feel bad. It just means the tip is 15. It’s a 15 at the tip, D/0. And then the file is getting bigger by four. So, it goes 15, 19, 23, and blah, blah, blah, all the way up. So, it’s getting progressively bigger. It’s usually a fixed-tapered file, same thing.

    So, they would say this is very appropriate for minimally invasive endodontics. I would tell you that is far different than 7, 8 or 9 percent in the apical one-third. So, they’re going to have apical thirds that are, you know, we have a 20/07, we have a 25/08, and we have a 30/09. And this is F1, F2 and F3. This could be ProTaper Gold. It could be ProTaper Ultimate. With Ultimate, the body is even smaller. The body at about D12, D8, D12, it’s about a 70 or an 80, so the older files we regressive had tapers, but the tapers allowed the file to be a little bit bigger to facilitate people with different needs and wants across the world.

    So, this is very different than this, so these people can have skinny preps over their whole length, but they’re not getting deep shape. In fact, their shapes are almost non-existent.


    But maybe the people who do root-appropriate shaping, for them, they’re being as minimally invasive as possible.


    They are, and a lot of these people –


    And have a good result.


    To be fair they’re using lasers, they’re using GentleWave.


    These or these?


    These people here. This is our minimally invasive crowd. And the minimally invasive crowd, they’re not all making these shapes. They might use a 25/04, but the point is they’re really emphasizing small shapes. Small shapes means small shapes coronal, middle and apical third. And I don’t want to do this right now, but if you do – well, we’ll do this one. A 20 file, and you can hold up your finger, it’s 20 at the tip. But at D1, it would be at 7, 27. At D2, it would be 34, and at D3, you could add another and it’s 41. The point is we’re getting a nice, deep taper.

    So, you’re going to ask me about that a little bit later, but you’re getting a completely different shape between these two concepts. This concept you have no chance to clean or fill unless you’re using $70,000 technology or perhaps $100,000 technology. I know that this was the Er:YAG but then we had, last time we talked about EdgeEndo’s, they have a $30,000 machine. But you’re using a lot of expensive money to overcome deficiencies from a minimal preparation.


    Okay, I think the issue here is maybe how you define minimally invasive because for someone like you, you want to be as minimally invasive as possible. That’s a positive thing. But some people might think that what you’re doing is not actually minimally invasive, that it has to be these sizes.


    Oh, they would probably argue that completely.




    The thing is the numbers of people that have this technology are probably less than 1 percent of a million dentists on planet Earth. So, that means what do we do with the other huge population of dentists that aren’t going to use this technology or don’t want the technology or doing maybe the EndoActivator. So, they need a little more shape in the deep shape area, but we can still be very minimally invasive up in that coronal and middle one-third, because that’s where we have historically as a profession overprepared teeth, and that’s predisposed to fractures.


    Okay. Moving on. What is deep shape and why is it important for irrigation?


    Okay, well we’re kind of skirting around it, aren’t we? So, here we’ll just do another little drawing here. And we’ll try to do a deep shape.


    Well, my question is why is it important for irrigation, but also does it impact obturation as well. Maybe you can answer both of those.


    If we just look at a section through the apical one-third, then if you have a 20 down here at the tip, deep shape, if you have 7 percent, we already did this, at D1, D2, D3, D4, D5, and if we had 7/27 – help me out, 34. What’s the next one? 41, 48, 56.


    55. Or 55.


    And where are we, one, two, three. Anyway, you’re going to be about a 60, a size 60, in the junction of the bottom of the middle one-third and at the top of the apical one-third. This means we have more volume, and if you have more volume, you have more reagent in here. And if you have more reagent in here, you can stick a device in to agitate that like the SmartLite Pro EndoActivator. And you can begin to see more movement laterally into this un-instrumental part of the canals. That’s lateral cleaning.

    So, deep shape gives you a bigger volume of liquid. It allows you to activate a bigger volume of liquid to clean better, and of course, it – the taper alone prevents what GentleWave reports constantly, we even cited an article last time that there was significant more sodium hypochlorite dispensed to the root with a 20/02 preparation as compared to standard irrigation. So, that leaves the sodium hypochlorite action.

    So, the deep shape is also holding your reagent and the deep shape is also holding your obturation materials when you three-dimensionally fill, thermal soften, and then give that press and mold and adapt the gutta percha into the cross-sectional geometries.


    Okay. I did have one question. If you have a deeper shape towards the apex, is it easier to obturate because you can maybe get the cannula down, or whatever you’re using to press, down further?


    Well, you can get your cannula down deeper, and when you’re irrigating, okay –


    Oh okay, so I mean for the –


    You’re meaning the plugger.


    The plugger, right.


    And you can get your plugger closer to length, and with Nathan Lee’s new conform fit gutta percha that Dentsply sells internationally, it has a longer heat wave, so you don’t even have to get within 5 millimeters anymore. You can get back 6 or 7 millimeters and you’ll still get a heat wave right to the terminus of that cone. So, when your plugger is up here, you know, and you’re pushing vertically, you know, and you have a canal down here —well, when you thermal soften your gutta percha in the apical third, you’ll get a heat wave.

    So when that plugger comes down on that thermal softened gutta percha, it captures the lateral walls, and that’s what tends to hold it, as you vertically compress it and cork the apex. So, deep shape helps you irrigate better. Thank you. If the cannula is placed deeper easily, passively. And then the pluggers can fit nicely through the body of the canal. Generally, the coronal two-thirds is the straight away portions of the canal, or less curved, and you can get your pluggers closer to length so you can adapt your gutta percha.


    Okay. Next question. What does it mean exactly when you say rotary first? Isn’t that counter-intuitive and perhaps dangerous?


    Well, I guess I’ll go back the other way. Okay, for my whole life, that means 48 years of teaching, I’ve always talked about cathaterizing canals. Our group, Marsh Two, John West, we coined the word “glide path.” We’ve talked about secured canals. A secured canal was a canal that had a smooth, reproducible glide path over the apical one-third. So, when we have that, we could then go from manual, your question, to mechanical.

    Well. technology kept moving, and time intervened, and over the years, we had better metals, we had better cross-sections, we had different ideas that could be built inside the metal to produce files that were safer. So, when we were building ProTaper Ultimate, as an example, we did hundreds and hundreds of teeth, and what we began to find out is that mechanical could reach length in extracted mandibular molars about 80 percent of the time. That means about 20 percent of the time when the file wouldn’t easily go, we would have to grab a manual file and cathaterize those canals. And then once we had a 10 loose, we could go back to the slider, and we could expand the glide path and go ahead with our shaping.

    So, it sounds intuitive that you would want to try it, but there were so many broken instruments over the years that we always said you have to use a manual file, at least to – I used to say a 15. So, when rotary first came out in the 90’s, we said don’t even stick a rotary file in until you have a loose 15 at length. Well a loose 15 is almost a 20, but technology has changed since 2001, and files have gotten dramatically better, cross sections and like I said, metallurgy. So, when you start to think of those possibilities, we found out we could mechanically get to length.

    Well, the benefit of this is you are more efficient, that makes sense, but we wouldn’t do it if it wasn’t safe. So, I’m not going to give a lesson on how to use that file, but I want the colleagues to understand that about 20 percent of the time you’re going to need to use a manual file, and that’s okay. But if I can help you 80 percent of the time get to length, you’re going to be more efficient, you’re going to have the best glide path you’ve ever had, so your shaping files can easily follow. You’ll have less iatrogenics and less iatrogenics means things like blocks, ledges, transportations and perforations. So, you get safety, efficiency, and finally, you have less post-op pain.

    And this is huge because a file that’s spinning or a file that has unequal bi-directional angles is eventually always making circles, 150 minus 20. 30 is a net of 120 and 120 after three cycles, that’s even making a reciprocation probably making it a circle. So, when a file is making circles, it’s collecting debris, it’s augurated up and away from length, up into the pulp chamber. So, these three things are huge benefits, and patients benefit, doctors benefit, and you stay out of trouble.

    So, when it doesn’t go, don’t worry, just grab your viscous chelator, grab your manual file, catheterize, get to length, get a working length, and then do what you were always doing.


    So, this kind of actually relates to the next question which was –




    Not yet. Which is are there benefits to doing rotary first besides simply saving time? Well, you just kind of covered that right there. That was the next question. I do have just one other question. Now what are the minimum requirements again before rotary first? Is it to catheterize to a 10?


    Well we used to teach for years you don’t even think of a rotary file or I’ll just say mechanical because there’s reciprocation too, and that’s – okay. So, whether you’re spinning circles or reciprocating, that’s mechanically driven. We said don’t even go there until you had an original 15 at length.




    Then technology improved and we we’ve got it back to a 10. It’s much safer. The most dangerous file in the business is a 15 stainless steel hand file, everybody. I’ve talked about that for years, so you can just go to my website and read and you’ll see a whole bunch of that stuff. But when we got to a 10, that was a nice step forward, proverbially, but we hadn’t reached the summit yet. And so, with Ultimate and with all these doing hundreds of molars and these were long ones, narrow ones, curved ones, Machtou and I discovered quickly we could get to length a little over 80 percent of the time.


    Without even doing a 10?


    With no 10 file.




    It was our first file, so it was a rotary first concept. And then the proof of concept was the 80 percent. So, we realized if you hold the handpiece really loose, just bounce it between the index finger and the thumb and the webbing, and just let the handpiece supported there, and just let it get pulled in. It doesn’t get sucked in. It doesn’t get run in and dig and gouge and you’re out of control. It will just float and run. As long as it’s running, stay the course. If you see the rubber stop moving ever closer to the reference point, you’re good.

    If it bogs down and won’t go, take it out because it might not be that it won’t go; it might be there’s so much debris on the flutes of that file that it pushes the file off the wall and the file can’t grab the wall to engage and cut and get pulled in. So, clear the blades and put some more viscous chelator in and go back in, and if it doesn’t go that time, then grab your 10 hand file, your 10 file. You might have to grab an 8. You could even grab an 06, but normally you’re going to grab your 10 and catheterize the canal, then go back to the slider, which is the first instrument in the ProTaper Ultimate family of instruments.


    Okay. So, rotary first, but totally passively, no pushing.


    No packing, no pumping.




    And let’s say it again, totally passively.


    Well, that is all the time we have for the questions today, but thank you very much.


    Well, the one we didn’t cover was the one that was going to make the biggest difference for them, but we’ll get it next season.


    Maybe we’ll just do a Q&A on just that one question.


    Yeah, thanks everybody, because it’s always fun being up here with my daughter, Lisette, and this wraps up this season, but I hope you enjoyed it and we’ll have a lot of interesting stuff and informative stuff so we can continue learning together.


    You’ll see us in a moment because we do have a special close for you so –


    I hope it’s offsite.


    Yeah. You’ll see. It’s a surprise.

    CLOSE: Favorite Places – Top of a Parking Garage


    Okay, so we got in our cars and we drove downtown, and now we’re at the top of a parking garage, and there’s not very many cars around us. But the reason why we came here is because there’s so many of these parking garages in Santa Barbara, almost on every block, and the tour books will never tell you to go to the top of a parking garage to check out the view. But you can get some interesting perspective.

    Behind us right here we have the Courthouse. The tour book will tell you to go to the Courthouse. But then when you’re at the Courthouse, can you really see the Courthouse? So, but now you can see it really well. What time is it, Dad?


    Well I just heard 12 bells, so I guess we’re just after 12:00 p.m.


    Have you ever been up there at the top?


    Once. It’s a remarkable architectural structure in Santa Barbara. In fact, in destination resorts people will come here, they hit the beach, they go to the Wharf.


    The Mission.


    The Mission, and the Clock Tower, they like to go there. On the other side of the Clock Tower is the Sunken Gardens, and I’ve heard Jacque Cousteau there before, but a lot of people come into town, and they’ll give like a little speech or a talk, and they can – in the Sunken Gardens, it’s very nice. It can accommodate maybe 1,000, 2,000 people. So, it’s –


    A lot of weddings happen there in the Sunken Gardens.


    Yeah, you got married over there, didn’t you?


    We got married, but we just had a very, very small ceremony, just me, my husband, and the kids, and it was just on the lawn, like in the Sunken Gardens area.


    And then you notice we have fog this time of year, and the fog is breaking, and we’re going to have a beautiful, beautiful afternoon, but you start to see some blue sky, and it’s coming over the mountains. In fact, our families all live on the Riviera, so that hill right behind us that you see through the gloom and the fog, is the Riviera.


    Over there’s the Granada Building. And that’s a pretty famous building.


    You go to the Nutcracker, right?


    You see the Nutcracker there every year. I think the bottom part is a giant theater, but the top is offices.




    So –


    Yeah, I have some referrals that used to practice up there in the Granada.


    Right on the other side of us is State Street, and that’s the downtown, and if you come and walk on State Street, you’ll probably see through the buildings, maybe the Courthouse Tower.


    Well you know what I’m thinking?




    They’ve seen the Wharf, they’ve seen City College, which is right out on the coast, and that’s where we flew the flight cause we were launching Ultimate. Remember that?




    I took a little fall myself, personally. And then we’re now on a parking lot garage. So, maybe we’re giving enough information that they’ll have a compelling reason to visit us live for our live audience of The Ruddle Show.




    People don’t know that, but we usually have 50, 100 people in the theater watching our show live. So, you might want to be one of those people and get a ticket. Yeah, why not?


    One thing we’re always doing on The Ruddle Show is we’re trying to get you to think a little differently, get you to get a different perspective. So, maybe when you’re driving to work tomorrow you take a different route and get a different perspective.


    Yeah, we’re getting our different fresh perspective out here with the fog breaking up, the sun is coming out, and so get your fresh perspective this summer so when we join you in the fall, and you come to The Ruddle Show, we’ll be all juiced up and ready to go.


    So, thanks for watching Season 7. We’ll see you again for Season 8 in the fall, but we’ll also be kind of coming at you a little differently in the summer. So, thanks for watching.


    Thank you. See you then.

    [music playing]



    The content presented in this show is made available in an effort to share opinions and information. Note the opinions expressed by Dr. Cliff Ruddle are his opinions only and are based on over 40 years of endodontic practice and product development, direct personal observation, fellow colleague reports, and/or information gathered from online sources. Any opinions expressed by the hosts and/or guests reflect their opinions and are not necessarily the views of The Ruddle Show. While we have taken every precaution to ensure that the content of this material is both current and accurate, errors can occur. The Ruddle Show, Advanced Endodontics, and its hosts/guests assume no responsibility or liability for any errors or omissions. Any reproduction of show content is strictly forbidden.

    DISCLOSURE: Please note that Dr. Ruddle has received royalties on and/or continues to receive royalties on those products he has designed and developed. A complete listing of those products may be found at

    Watch Season 11


    s11 e01

    Delving Deeper Again

    Financial Investing, the Tooth or Implant, Accessing & Flashing Back


    s11 e02

    Artificial Intelligence & Disassembly

    Differentiating Between AI Systems & Paste Removal


    The Ruddle Show

    Commercial Trailer S11

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    s10 e01

    Delving Deeper

    Progressive Tapers & DSO Troubles


    s10 e02

    The Dark Side & Internal Resorption

    The Resilon Disaster & Managing Internal Resorptions


    s10 e03

    Advanced Endodontic Diagnosis

    Endodontic Radiolucency or Serious Pathology?


    s10 e04

    Endo History & the MB2

    1948 Endo Article & Finding the MB2


    s10 e05

    Collaborations & Greatness

    Crown Removal vs. Working Through & Thermal Burns Q&A


    s10 e06

    Vital Pulp Therapy

    Regenerative Endodontics in Adolescents


    s10 e07

    Endodontic Surgery & Innovation

    Surgery Photo Review & Exciting New Technology


    s10 e08

    Clinician Influence & Fractures

    Swaying Treatment & Radicular Root Fractures


    The Ruddle Show

    Commercial Trailer S10

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    s09 e01

    Moving with the Cheese & Delving Deeper

    A Better Understanding of Change & File Brushing


    s09 e02

    The Dark Side & Post Removal

    Industry Payments to Academics & Removing a Screw Post


    s09 e03

    3D Tomosynthesis

    Special Guest Presentation by Dr. Don Tyndall


    s09 e04

    Controversies & Iatrogenic Events

    Sharing Knowledge Pros/Cons & Type II Transportations


    s09 e05

    File Movement & Learning

    Manual and Mechanical Options & Endoruddle Recommendation


    s09 e06

    AAE & Endo/Perio Considerations

    Annual Meeting & Root Amp, Hemisections & Implants, Oh My!


    s09 e07

    Knowing the Difference & Surgery

    Case Discernment & Lateral Repair


    s09 e08

    Fresh Perspective & Apical Divisions

    Fast Healing & Irregular GPM and Cone Fit


    The Ruddle Show

    Commercial Trailer S09

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    s08 e01

    Endo/Perio Considerations & Recent Article

    Crestal/Furcal Defects & ProTaper Ultimate


    s08 e02

    WaveOne Gold

    Special Guest Presentation by Dr. Julian Webber


    s08 e03

    Microscope Tips & Perforation Management

    Q&A and Crestal & Furcal Perf Repair


    s08 e04

    Knowing the Difference & Calcification

    Esthetic vs. Cosmetic Dentistry & Managing Calcified Canals


    s08 e05

    Tough Questions & Sealer-Based Obturation

    The Loose Tooth & Guest Dr. Josette Camilleri


    s08 e06

    AAE Discussion Forum & 3D Irrigation

    Trending Topics & the SLP EndoActivator


    s08 e07

    Working Length & Microscope Tips

    Determining Accurate WL & Microscope Q&A, Part 2


    s08 e08

    Artificial Intelligence & Common Errors

    Incorporating AI & Endo/Restorative Errors


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    Special Reports


    special e06


    As Presented at the John Ingle Endo Symposium


    special e05


    The Importance of Simplicity & Getting Back to Basics


    special e04


    Personal Interview on the Secrets to Success


    special e03


    The Launch of an Improved File System


    special e02


    The Way Forward

    Watch Season 7


    s07 e01

    Articles & Preferred Access

    Writing Projects & Ruddle’s Start-to-Finish Access


    s07 e02

    Patient Protocol & Post Removal

    CBCT & the Post Removal System


    s07 e03

    Avoiding Burnout & Ledge Management

    Giving New Life to Your Practice & Managing Ledges


    s07 e04

    Start-To-Finish Endodontics

    Special Guest Presentation featuring Dr. Gary Glassman


    s07 e05

    Laser Disinfection & Obturation

    The Lightwalker vs. EdgePRO Lasers and Q&A


    s07 e06

    Extra-Canal Invasive Resorption

    Special Case Report by Dr. Terry Pannkuk


    s07 e07

    GentleWave & Microsurgery

    Every Patient Considerations & Surgical Crypt Control


    s07 e08

    Artificial Intelligence & Endodontic Concepts

    Update on AI in Dentistry and Q&A


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    s06 e01

    Comparisons & NSRCT

    Chelator vs NaOCl and Managing Type I Transportations


    s06 e02

    Special Guest Presentation

    Dr. Marco Martignoni on Modern Restoration Techniques


    s06 e03

    International Community & Surgery

    Breaking Language Barriers & MB Root Considerations


    s06 e04

    Launching Dreams

    ProTaper Ultimate Q&A and Flying a Kite


    s06 e05

    Rising to the Challenge

    Working with Family & Managing an Irregular Glide Path


    s06 e06

    Controversy… or Not

    Is the Endodontic Triad Dead or Stuck on Semantics?


    s06 e07

    Endodontic Vanguard

    Zoom with Dr. Sonia Chopra and ProTaper Ultimate Q&A, Part 2


    s06 e08

    Nonsurgical Retreatment

    Carrier-Based Obturation Removal & MTA vs. Calcium Hydroxide


    The Ruddle Show

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    Watch Season 5


    s05 e01

    Common Endo Errors & Discipline Overlap

    Apical and Lateral Blocks & Whose Job Is It?


    s05 e02

    Post Removal & Discounts

    Post Removal with Ultrasonics & Why Discounts are Problematic


    s05 e03

    EndoActivator History & Technique

    How the EndoActivator Came to Market & How to Use It


    s05 e04


    New Disinfection Technology and Q&A


    s05 e05

    Exploration & Disassembly

    Exploratory Treatment & the Coronal Disassembly Decision Tree


    s05 e06

    Advancements in Gutta Percha Technology

    Zoom Interview with Dr. Nathan Li


    s05 e07

    By Design... Culture & Surgical Flaps

    Intentional Practice Culture & Effective Flap Design


    s05 e08

    Workspaces & Calcium Hydroxide

    Ruddle Workspaces Tour & Calcium Hydroxide Q&A


    s05 e09

    Cognitive Dissonance

    Discussion and Case Reports


    s05 e10

    50 Shows Special

    A Tribute to The Ruddle Show’s First 5 Seasons


    The Ruddle Show

    Commercial Intro S05

    Watch Season 4


    s04 e01

    Tough Questions & SINE Tips

    Who Pays for Treatment if it Fails and Access Refinement


    s04 e02

    Endodontic Diagnosis

    Assessing Case Difficulty & Clinical Findings


    s04 e03

    CBCT & Incorporating New Technology

    Zoom with Prof. Shanon Patel and Q&A


    s04 e04

    Best Sealer & Best Dental Team

    Kerr Pulp Canal Sealer EWT & Hiring Staff


    s04 e05

    Ideation & The COVID Era

    Zoom with Dr. Gary Glassman and Post-Interview Discussion


    s04 e06

    Medications and Silver Points

    Dental Medications Q&A and How to Remove Silver Points


    s04 e07

    Tough Questions & Choices

    The Appropriate Canal Shape & Treatment Options


    s04 e08

    Q&A and Recently Published Articles

    Glide Path/Working Length and 2 Endo Articles


    s04 e09

    Hot Topic with Dr. Gordon Christensen

    Dr. Christensen Presents the Latest in Glass Ionomers


    s04 e10

    AAE Annual Meeting and Q&A

    Who is Presenting & Glide Path/Working Length, Part 2


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    s03 e01

    Treatment Rationale & Letters of Recommendation

    Review of Why Pulps Break Down & Getting a Helpful LOR


    s03 e02

    Profiles in Dentistry & Gutta Percha Removal

    A Closer Look at Dr. Rik van Mill & How to Remove Gutta Percha


    s03 e03

    Artificial Intelligence & Endo Questions

    AI in Dentistry and Some Trending Questions


    s03 e04

    How to Stay Safe & Where to Live

    A New Microscope Shield & Choosing a Dental School/Practice Location


    s03 e05

    3D Disinfection

    Laser Disinfection and Ruddle Q&A


    s03 e06

    Andreasen Tribute & Krakow Study

    Endodontic Trauma Case Studies & the Cost of Rescheduling


    s03 e07

    Ruddle Projects & Diagnostic Imaging

    What Ruddle Is Working On & Interpreting Radiographs


    s03 e08

    Obturation & Recently Published Article

    Carrier-Based Obturation & John West Article


    s03 e09

    Retreatment Fees & the FRS

    How to Assess the Retreatment Fee & the File Removal System


    s03 e10

    Research Methodology and Q&A

    Important Research Considerations and ProTaper Q&A


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    Commercial Opener S03


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    Watch Season 2


    s02 e01


    Product History, Description & Technique


    s02 e02

    Interview with Dr. Terry Pannkuk

    Dr. Pannkuk Discusses Trends in Endodontic Education


    s02 e03

    3D Disinfection

    GentleWave Update and Intracanal Reagents


    s02 e04

    GPM & Local Dental Reps

    Glide Path Management & Best Utilizing Dental Reps


    s02 e05

    3D Disinfection & Fresh Perspective on MIE

    Ultrasonic vs. Sonic Disinfection Methods and MIE Insight


    s02 e06

    The ProTaper Story - Part 1

    ProTaper’s 20+ Year Journey as Told by the Creators, the 3 Amigos


    s02 e07

    The ProTaper Story - Part 2

    ProTaper’s 20+ Year Journey as Told by the Creators, the 3 Amigos


    s02 e08

    Interview with Dr. Cherilyn Sheets

    Getting to Know this Top Clinician, Educator & Researcher


    s02 e09

    Broken Instrument Removal

    Why Files Break & the Ultrasonic Removal Option


    s02 e10

    3D Obturation & Technique Tips

    Warm Vertical Condensation Technique & Some Helpful Pointers


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    The Ruddle Show

    Commercial Opener S02

    Watch Season 1


    s01 e01

    An Interview with Cliff Ruddle

    The Journey to Becoming “Cliff”


    s01 e02

    Microcracks & the Inventor's Journey

    Ruddle Insights into Two Key Topics


    s01 e03

    Around the World Perspective

    GentleWave Controversy & China Lecture Tour


    s01 e04

    Endodontic Access

    What is the Appropriate Access Size?


    s01 e05

    Locating Canals & Ledge Insight

    Tips for Finding Canals & the Difference Between a Ledge and an Apical Seat


    s01 e06

    Censorship in Dentistry

    Censorship in Dentistry and Overcooked Files


    s01 e07

    Endodontic Diagnosis & The Implant Option

    Vital Pulp Testing & Choosing Between an Implant or Root Canal


    s01 e08

    Emergency Scenario & Single Cone Obturation

    Assessing an Emergency & Single Cone Obturation with BC Sealer


    s01 e09

    Quackwatch & Pot of Gold

    Managing the Misguided Patient & Understanding the Business of Endo


    s01 e10

    Stress Management

    Interview with Motivational Speaker & Life Coach, Jesse Brisendine


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    08.31.2023 Update



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    03.03.2022 Update


    Happy New Year



    Behind-the-Scenes Studio Construction


    The Ruddle Show
    Season 11

    Release Date Show Get Notified
    SHOW 91 - Delving Deeper Again
    Financial Investing, the Tooth or Implant, Accessing & Flashing Back
    SHOW 92 - Artificial Intelligence & Disassembly
    Differentiating Between AI Systems & Paste Removal
    SHOW 93 - The ProTaper Ultimate Slider
    Special Guest Presentation by Dr. Reid Pullen
    SHOW 94
    Title Coming Soon
    SHOW 95
    To Be Determined
    SHOW 96
    To Be Determined
    SHOW 97
    To Be Determined
    SHOW 98
    To Be Determined
    SHOW 99
    To Be Determined
    SHOW 100
    To Be Determined
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