Comparisons & NSRCT Chelator vs NaOCl and Managing Type I Transportations

This new season kicks off with a promotion of our 2 off-season Special Reports that you definitely don’t want to miss. Next, Ruddle and Lisette debut a new segment, “Knowing the Difference,” with this first segment featuring Chelator vs. NaOCl. Then, Ruddle is back at the Board for nonsurgical retreatment, identifying transportation types and focusing on managing Type I transportations. Stay tuned for an exciting Ruddle Flashback, this time flashing back 30 years to Ruddle and Lisette’s visit to the Demilitarized Zone in South Korea.

Show Content & Timecodes

00:10 - INTRO: Special Reports Promotion
06:29 - SEGMENT 1: Knowing the Difference: Chelator vs NaOCl
19:01 - SEGMENT 2: Transportations: 3 Types and Managing Type I
39:44 - CLOSE: Ruddle Flashback – Visit to the DMZ

Extra content referenced within show:

  • Ruddle’s Disinfection Protocol (see downloadable PDFs below)
  • The Ruddle Show Graphic "Knowing the Difference - Chelator vs Sodium Hypochlorite" (see downloadable PDF below)
  • Ruddle CJ: Ch. 25, Nonsurgical Endodontic Retreatment. In Pathways of the Pulp, 8th ed, Cohen S, Burns RC, eds. St. Louis: Mosby, pp. 875-929, 2002

  • Extra movie/video content:

  • Just-In-Time® Video from “Reagents for Disinfection: NaOCl & Chelator”
  • Just-In-Time® Video from “3-D Disinfection: Disinfection Methods”

  • 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

    The Ruddle Show Graphic
    "Knowing the Difference - Chelator vs Sodium Hypochlorite"
    Oct 2021

    Featured Graphic from The Ruddle Show: Knowing the Difference - Chelator vs Sodium Hypochlorite

    Ruddle Article
    “Endo Disinfection: The Sonic Advantage”
    Jun 2017

    In the United States, alone, more than 100,000 dentists perform tens of millions of operative, restorative, and reconstructive procedures on an annual basis. Certainly, these dental procedures are primarily directed toward eliminating carious lesions, esthetically restoring teeth, and functionally moving patients toward optimal oral health...

    Ruddle Article
    “Endo Disinfection: Tsunami Irrigation"
    Feb 2008

    There are enormous differences in opinion regarding the potential to three-dimensionally clean a root canal system. Elimination of pulpal tissue, bacteria when present, and their related breakdown products is directly influenced by a series of procedural steps that comprise start-to-finish endodontics...

    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 Article
    "Nonsurgical Endodontic Retreatment"
    Jun 2004

    There has been massive growth in endodontic treatment in recent years. This increase in clinical activity can be attributable to better-trained dentists and specialists alike. Necessary for this unfolding story is the general public's growing selection for root canal treatment...

    Ruddle 'Endodontic Therapy' Interview
    "NSRCT of Endo Failures: Treatment Concepts & Considerations"
    Nov 2001

    In a previous interview, Endodontic Therapy and Dr. Cliff Ruddle discuss nonsurgical retreatment and the integration of traditional and modern techniques for achieving excellence and producing predictable outcomes...

    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.

    INTRO: Special Reports Promotion


    Welcome to The Ruddle Show! I’m Lisette and this is my dad, Cliff Ruddle. And we’re really happy you joined us. How are you doing today?


    More than good.


    Well, we’re starting our sixth season of The Ruddle Show and I have some good news and some bad news.


    Oh no, what’s the good – what’s the bad – what’s the good news?


    Well first I’ll start with the bad news, because it’s good to finish with the good.


    That’s true.


    The bad news is we are only going to have eight shows this season instead of ten. So, this may disappoint some of our viewers, but the good news is that we released two special reports in September, during the off-season, and those are available to watch. The first special report is on the launch, the recent launch, of ProTaper Ultimate which launched September 1, and in that special report, you talked about how ProTaper has changed, why it changed, and shared some of your excitement, correct?


    That’s correct. Well, in that show that they’ll – every one of them will watch, you know that, we talked about some of the things that made the file go beyond ProTaper Gold which is the number one file, has been for the last 15 years. So, what we did is we made a more minimally invasive preparation, I like to say, upstairs in the body of the canal to stay away from furcal danger and end up with endodontically strong teeth. And then we wanted to have fewer instruments. We wanted greater safety and well, we want to do a bigger range of anatomy. And then the one that I think is one of the most important ones is rotary first. I’ll just leave it at that.




    Cause that’s controversial, but if they see it all in the context, it’s a game changer.


    We’ll definitely check it out, and then in just a few shows from now, we’re going to Q&A a Q&A on ProTaper Ultimate, so watch for that. And then the second report you did, the special report that we did, it’s an interview with you talking about the secrets to your success, and the special thing about that is that mom interviewed you. So, how was that? How did that interview come about?


    Well, she was along for the journey so the things that we did together, which means she did 90 percent of it and did 10, but we always call it 50/50 work, the infrastructure, gotta have a great infrastructure, gotta assemble the right team, then you gotta develop a culture. We talked a little bit about how to make yourself better and stay relevant. We talked about the dentist as owner, leader, manager, marketer.

    We’ve also talked about how to overcome adversity and how to create success by design. So, I think there was a lot of little things in there that I’ve had to learn the hard way, you know, years and years. So, if a younger dentist watched this stuff more or less right now, you could be doing what Ruddle is doing now but you could be doing it 25, 30 years earlier in your career.


    And what was this interview for?


    Oh, we did it for the 12th World Endodontic Conference. It’s called IFEA. It’s the International Federation of Endodontic Associations, and it was a meeting that was collaborated with the Indian Endodontic Society because it was out of Chennai.


    Well, definitely check it out. I actually really loved this interview, and also, if you’re not aware, we did do two other special reports that are also available to watch on our website. We did them back in April of 2020 and they’re about COVID, and the first one is – it was like a global perspective and we got – we saw how clinicians around the world were dealing with the outbreak of the pandemic at the initial outbreak, so it’s interesting. And then we also did another one where we envisioned the way forward out of the pandemic. So –


    Well, you know, I’m going to brag about you. I wasn’t up for doing two COVID specials, and the audience needs to understand this happened back in April of 2020.




    So, what I’m pretty proud about her is she started drilling down and getting underneath the surface, and we talked about stuff in those shows that actually, if you look back now, we were a little bit prescient. We talked about the therapeutics and the vaccine that we sure hoped that would come. And then, of course, with the therapeutics, we talked about hydroxychloroquine and remdesivir, ivermectin, Regeneron –


    Well, we didn’t talk about –


    We didn’t talk about Regeneron.




    But we were talking about early therapeutics and it’s interesting to see how the world’s attacking not only on therapeutics, but on vaccines, so yeah, we wanted to give dentists the chance to feel like they weren’t all alone in this, and there was a whole network of people behind them and they could PPE it up and get in there and do triage on those emergencies. So, I thought it was pretty good, especially as I look back, I was pretty proud of what we did.


    Yeah, and it’s just – even, I mean it’s only like pretty much a year and a half ago, but you already – it’s already kind of an interesting historical perspective to look back on when it was first happening, all this was happening.


    Can I be commercial?


    Go ahead.


    We talked about Ultimate in its launch in September, but I want to just tease everybody. We have a fabulous disinfection technology, cordless, hand-held, simple, simple, simple that will go way beyond the Endo Activator. So, stay tuned.


    That sounds like it might be another special report.




    Okay, well we have a great show for you today, and let’s get going.

    SEGMENT 1: Knowing the Difference – Chelator vs NaOCl


    So, we have a new segment to debut for you today, and it’s called Knowing the Difference because sometimes products or techniques might seem very similar and you might even think they’re exactly the same and interchangeable, but often the seemingly similar have important differences which in turn make them more suited to accomplish certain procedures, for example. So, the French 18th century author, Madame de Stael said, “Wit consists in knowing the resemblance of things that differ, and the difference in things that are alike.”

    So, with that in mind, we’re going to look at some substances that are seemingly similar, but have important differences, and we’re going to start with chelator versus sodium hypochlorite. So we have a graph. Let’s bring that up. Okay. So, why don’t you start by explaining it, maybe focusing on chelators first.


    I’m going to talk a little bit here about this left column. When you start a procedure, you cut your access, and there are the orifices, assuming there are identifiable orifices. And it could be necrotic tissue in the orifice, or it could be vital tissue. We use a viscous chelator, or I teach using a viscous chelator, and I have for like my whole career, because as a teacher, I’ve realized if you go to sodium hypochlorite, there’s very little sodium hypochlorite below the orifice. And I’ve given this analogy many, many times on this show, but I’ll say it again.

    So, in other words, you have a little bucket of water, the little kid sticks his fist in the water and the fist displaces most of the water in the bucket. So, when you have a pulp chamber full of sodium hypochlorite and you start to go below the orifice of the file, there’s almost no irrigant below the orifice. In fact, it’s usually just a dry canal. It could have parulis, it could have hemorrhage, things like that, but there’s not sodium hypochlorite. And there’s such little space initially that the Clorox can’t get in there and then what little space is there the file displaces, like the fist in the bucket of water, the file displaces the sodium hypochlorite.

    So, viscous chelators, like the viscosity of toothpaste, I fill the chamber with viscous chelator, so I pass my clean file through the viscous chelator, I butter the file. By surface tension the viscous chelator stays on the flutes of the file more effectively, and I get three big things. I get a superior lubricant that reduces friction between file and dentin and pulp tissue and fibrotic stones and fibrotic tissue, and then I also get an emulsifier. So, viscous chelators prevent the re-adherence of vital tissue. When you go into a canal and pull out the file, the tissue re-adheres to itself, and there’s no favorable pilot hole for the next sequential instrument.

    So, what a viscous chelator does, emulsification, it prevents the re-adherence to tissue, it leaves you a favorable pilot hole so the file can have space to go. And then finally you’re making debris, you’re generating debris that needs to be removed and we need to keep that in flotation, in suspension, so that it doesn’t settle into the canal and promote or encourage a block. So, I like an aqueous chelator initially to scout the canal –




    Viscous. Thank you. I need a viscous chelator during the scouting procedure, and that means negotiating the canal, reaching length, patency and checking the glide path. So, I use a viscous chelator until I have a secured canal, and a secured canal is that canal that has a smooth, reproducible glide path, or slide path. Once I get to length and do those three things, working length, patency, and slide path, it’s gone and never used again, viscous chelators.

    Now I’m going to skip to aqueous. Aqueous is at the other end of the procedure because all these shaping files that occurred in the middle, they’re all generating debris, and that debris gets burnished into the lateral anatomy, into tubules and into the entry into lateral canals. And even though a lot of the debris comes out on the flutes of the file and it appears loaded and you flush and you see all this debris leaving, please remember, there’s a lot of residual debris in the eccentricities off the router part of canals. So, the aqueous chelator removes the smear layer, not the viscous, the aqueous.

    And it promotes disinfection because by removing the smear layer, you’re opening up all your lateral anatomy. Now you can agitate sodium hypochlorite and you can actually get it to what, penetrate, circulate and digest tissue from the un-instrumental portions of the root canal system. So, that’s a little distinction between viscous and aqueous and I’m asked that a lot and, you know, because you’ve written how many answers to this over how many years, and we’re still asked all the time.


    Okay. So, I’m understanding that you first use the viscous chelator to scout and secure the canal, and examples of that I guess are ProLube, Glyde and RC Prep?


    Very good.


    And then after shaping, you use the aqueous chelator to promote disinfection and remove the smear layer.


    That’s right.


    So, in the middle, we have sodium hypochlorite. So, why don’t you tell us a little bit more about how you utilized this drain shaping.


    Okay, so for shaping canals, you’re using some kind of an instrument, could be like a Wave 1, use one shaping file, or you could be using two or three or four shaping instruments. But the point is every shaping file is making more space progressively, progressively, so we improve our volume of sodium hypochlorite. Sodium hypochlorite is cool, it’s the only thing we have, the only thing we have that digests tissue and pulpal remnants, kills all microorganisms on contact, and their biproducts. and destroys viruses and spores.

    So, the sodium hypochlorite is really good when we’re doing bodywork and we’re preparing and shaping, floats a lot of debris out of the canal because it’s aqueous. But then we’ve got to remember when we’re all done shaping, we need to move to that next column and think about, you know, getting the smear layer off the wall because we’re going to go into a disinfectant protocol, which this is really not a disinfectant protocol as you and I were talking about earlier this morning.

    And one more comment, you asked me this, and it was very intuitive, and you asked me this on a Zoom meeting recently, but you said, “Would you ever use aqueous chelator along the journey?” And I thought that was really smart because I’ve actually taught that. In other words, why do we take the smear layer off at the very end? Maybe we should be taking the smear layer off along the journey.


    Yes, I actually asked you like maybe if you just pre-enlarged the canal, then maybe, you know, flush out the sodium hypochlorite, use the EDTA, remove the smear layer and then more sodium hypochlorite, cause then you have like a really clean corolla one-third to then begin shaping or you’re scouting further along. So, I just didn’t know if that actually would be helpful to get – basically it’s washing the dishes as you’re cooking and not saving everything towards the end.


    Maybe we should leave it right there, but that was very intuitive. I did teach that in Santa Barbara seminars and hundreds and hundreds of doctors around the world came and trained, but we talked about EDTA even along the journey. But I don’t try to have a mixture. I liked what you said, and I’ll say it again. She’s saying if we’re going to use it after we take out a file to remove the smear layer, so take the file out, irrigate with EDTA, and take a 10 file or an Endo Activator and just stir the soup, and then flush, and then vacuum that out and top that off with sodium hypochlorite and continue shaping.


    Okay. And then the last thing I wanted to say is that we have examples of viscous chelators on this side, the ProLube, Glyde and RC Prep. Here we’re just saying 17 percent solution of EDTA. Are there other aqueous chelators or is that just pretty much the go-to?


    Yeah, I guess I should say over here, this and this are much the same. This is Ethylenediaminetetraacetic acid in a methyl cellulous suspension, whereas, this is just straight 17 percent, and then what she’s alluding to, is there anything else in this family of surfactants? See, EDTA is a surfactant. I forgot to say that. Surfactants lower surface tension, they reduce friction, and they help penetration of fluids. So, you want to use EDTA aqueous as a surfactant, and citric acid would be another example.


    Okay, but that’s maybe not used as much?


    It’s used more in periodontics, and I learned about it from periodontists years ago and I use it in surgery. You have a dehiscence on a root, got a flat back, you can use a little brush and paint this on, keeping it very localized on the tooth, and then you can expose collagen, so when you put the flap back, you can get better attachment, especially on a dehiscence where there is no bone.


    Okay, well I think we’ve actually really clarified the distinction between chelator and sodium hypochlorite and again, if you’re interested in the whole disinfection protocol, we’ll have a link to that in our Show Notes. The purpose here, though, is just to really help you understand how they’re similar, how they’re different, and what reagents to use when and why.


    Very good.




    Because we get asked this all the time. And you know, some people think it’s just a preference or, you know, why, and I hope today that they’ve got a little better understanding, at least in my head, why I use the rationale like I do.


    Okay, well –


    I do get a lot of anatomy.


    Now I would think that clinicians would be already pretty familiar with the differences and similarities between chelator and sodium hypochlorite, but it’s actually surprising how many questions we get asking for clarification. So, why do you think that there is this confusion that exists?


    Well, I think – there’s an old expression, “Who you are is where you were when” and we’re all products of our past, our teachers, our mentors, so what we put in our bags and took out of dental school, how we took the journey, what we exposed ourself to during the journey, courses, hands-on, you know, clinical courses, workshops, what you read, magazine articles, talking to colleagues, all these tend to influence us. And I think a lot of people are traditionally a little more reticent to change and they might do what they were always learning, and they have a certain protocol they follow.

    But I’d like everybody to be willing to change and understand if you’re not seeing a lot of anatomy on films, I shouldn’t – I’m off on a tangent. I just keep hearing how important it is to use the XP file or it’s really important to use lasers or it’s really important – Gentle Wave. That’s all fine, but I taught thousands of dentists to use like technology for less than $5 and you can clean and fill root canal systems, so some of this has a lot of evidence behind it for how we got our results, and it wasn’t just that we tried this and we tried that. There was a protocol and we followed it.


    Yeah. It sounds like the better you understand this type of situation here, the better you understand, it the more anatomy you’re going to be seeing.




    Because you know what each reagent is best for and when to use it. Okay, well that’s all we have time for this segment, Knowing the Difference, and next time we’re going to talk about the difference between calcium hydroxide and MTA. So, we might even be doing that later this season, so stay tuned for that.


    And when she says MTA, she means the family of tricalcium silicate putty fillers and that can even be bio dentine.


    Okay. Well thank you. Thank you for that information.

    SEGMENT 2: Transportations – 3 Types and Managing Type I


    Today we’re going to talk a little bit about managing apical transportations, and of course, I’ll talk a little bit about the etiology and I’ll start with that right now. Transportations, to define them, means latrogenically moving the physiologic terminus to a new location on the external root surface. So, that is a transportation. Schilder introduced this terminology back in the ‘60s, but it’s no wonder so many actually occurred. We have so many little turns and re-curvatures all in the last few millimeters of a root and then you think about traditional education, it was pretty much to get a 35 or a 40 file at length.

    And remember, these were 02 tapered files. So, a lot of times there wasn’t a lot of emphasis on taper. There was just an emphasis on getting big, stiffer files to length. So, as we went into NiTi, even NiTi at some of these sizes, becomes quite stiff, and a lot of the NiTi instruments aren’t 02 either; they’re like 04 and 06, et cetera. So, a lot of the transportations then occurred because colleagues carried bigger, stiffer files to length and they then got a 45 or 50 length or whatever was their protocol, and then they basically had a pretty parallel canal.

    So, what happens in this kind of a shape is we don’t have this kind of a shape, where we have narrowing cross-sectional diameters with our smallest diameter towards the terminus. Now we’re packing into resistance form. There is almost a complete parallel shape here, so it’s no wonder when obturation and hydraulics begin to happen and there’s lubrication because a sealer, it’s no wonder that the cone can move to the foramen and through. So, we see a lot of this in the world of retreatment and so this is one kind of a transportation, and that’s what we’ll be talking about today. Isn’t this fun?

    All right. So, I’m showing you a really great case by Jason West. It’s just the opposite of the case you just saw that didn’t have any shape over length. Basically, it was a parallel, huge tube. What you have here is flowing, progressively smaller tapers as you go towards terminus. No wonder the hydraulics can be developed out with all the anatomy. You can see anatomy here. You can see anatomy down here. You can see bifidity.

    So, when we developed a tapered shape, it also discourages moving the foramen, because we’re emphasizing a smaller terminal diameter with a little more apical one-third taper. So, you can either do it with big D0 files and no taper, or you can insist on smaller terminal diameters with more taper. So, that’s a great case to show, just to get started to get in our minds again what do good shapes look like. They talk about ‘the look.’ Schilder talked about “the look.’ The look was something you could see, and we would all say, “It looks like the concepts and the principles have been carried out exquisitely in this case.” It has the look.

    All right. So, Schilder gave us these objectives. He gave us five. I’m kind of combining two of them into one. A funnel-shaped preparation also is a preparation who’s at least in the apical third, the cross-sectional diameters are getting smaller, smaller, smallest at the terminus. Maintain the original anatomy. Go with the flow. However those systems are turning in multi-planar curvature, in and out of the primary beam, or mesial to distal, we go with the canals.

    Maintain the position of the foramen. That is the essence of the beginning of a transportation when you move it. So, if we don’t maintain it and we start to move it, now we start to have things that are not only A = pi r squared, we’re trying to seal a pretty good surface area, that’s assuming that it’s round, but if you start to have a round foramen and then we tear it and we move it over to here and it gets bigger, we have not only this A but we have a huge surface area to fill and keep it as small as practical. Working more, emphasize more on your taper versus your terminal diameter.

    All right. So, if you look at this animation, you look at this shaped canal, and we look at it a little bit more carefully, I’ll just summarize by showing a nice animation, and it’s about deep shape. Because Schilder’s preparations, his mechanical objectives that are famous, it always emphasize deep shape, whether that was said or not, it was pretty much this kind of a shape. And how we did this clinically is we’d go through a series of files.

    Oftentimes, we’d go through a series of hand files, 20 through 60, they were 2 percent tapered, and the question was is it really a 20? Is the diameter really a 20 at length? We didn’t say the file was binding circumferentially. It might only have two-wall binding or it could have circumferential binding. To answer that question, is it a 20 at length, we would say this clinically, I wonder if it’s a 20 down there? Where’s the 25 go?

    So, in a finished preparation, and you might have to go through these files several times, and we call the recapitulation, but in the old days, we’d go through it once, come back and go through it twice, but at some point when those files uniformly and progressively stepped up and out of the canal, we knew mentally, we could see it in our minds, that we had deep shape and we had a flowing preparation.

    It gave us a resistance form for our irrigants. Think of sodium hypochlorite accidents with almost no shaping versus a taper preparation, and then think about filling root canal systems where you have a capture zone to hold the gutta-percha laterally, vertically, because you have deep shape. So, that’s a really big deal. Are you having fun yet?

    So, let’s go a little bit more. Let’s just bring it home. How do you get root canal systems? You know what, you have deep shape. Deep shape promotes the exchange of irrigation. Deep shape confines our irrigant to the root canal system; deep shape gives us hydraulics. We pack into resistance form and out with the anatomy. Watch that load. Watch that plugger load that platform and stay on it 1001, 1002, count to 10, and you will have corked the apical one-third.

    So, that’s a little bit about the preparation, how we have deep shape and how we follow those mechanical objectives so that we end up with preparations that can be cleaned and filled. Well, if we just take it to a tooth, you can see that silver point is not only two, but it’s minutely through the foramen. The lesion is being traced by a gutta-percha point through a sinus track to a lesion of endodontic origin. This is not an apical peritonitis. You can use those words if you want, but this is lateral.

    So, it’s not apical, so let’s just say lesions of endodontic origin and they occur circumferentially and periradicular around these roots. So, the prescription is, and you can even see part of that preparation is way over here, so there’s a lot of space in there. There’s some laterally condensed, probably a single cone of laterally condensed gutta-percha right in here. Out with the gutta-percha, get the silver point out, and then we can go talk a little bit about what we need to do.

    Here we are with the cone fit. You can begin to see that we have good tug-back, it’s in the apical third, the cone is loose up in the body. We can syringe in with an injectable gutta-percha method. We can syringe in lateral gutta-percha. So, when we sear this off and we get our plugger in here and we push and we got vertically, we can pack our way up. We can mold this cone into the terminal third and out with the lateral canal and we can keep going, and we can backpack it, and then we can watch that over many, many years, and look at the predictability, the propensity for lesions of endodontic origin to heal when we change the internal biology.

    Okay. All this is about really can we manage these big foramen? Can we manage them? If you can get taper – I’m exaggerating. If you can get taper behind the terminus, then you have a good chance to control it. So, when they’re parallel and big, that’s when we have to and through stuff. So, let’s look at it. How do we get a transportation? It happens through three different ways. One, you can carry the same file to length, even if it’s NiTi. And because of shape memory, that file wants to be straight. It wants to straighten out. So, going repeatedly back to length of the same file can start to tear the foramen.

    Also can happen because you’re grinding big, stiff stainless-steel files to length. That’s another reason. And another reason it can happen is because you grind even bigger ones. So, not only in a step back preparation grinding files to length, but just say grinding a 30, a 35 and a 40 and God, this is fun, let’s go 50, 55, 60, and all of a sudden that little turn, that little turn in the canal, you didn’t follow it.

    So, if you look at the transportations, I have divided them years and years ago – 20 years ago, I divided the transportations. This is Ruddle nomenclature, into Type I, Type II and Type III. So, a Type I, here’s our physiologic. This is our physiologic terminus. Then a small tear. Class 2 is a bigger tear, and it’s going to take different methodology. We can’t just develop shape and then pack it as per usual. We’re going to have to use a barrier technique and that’s another transportation show that’s coming.

    And then a Type III oftentimes means orthograde treatment, where we not only want to improve the endodontics over the length of that canal, so we might have the top of the tooth open and access and be doing retreatment through the crown with a rubber dam on, and then at the conclusion, go in surgically and remove that big rip from the terminal part of that root through API section procedures and then retrograde for para lesions and retrograde seals. So, that’s the kind of things we’re going to do.

    But right now, we’re going to talk about a Class 1. A Class 1 or a Type 1 is a small movement. So, this would have represented our physiologic terminus, and because of either grinding the bigger files and the bigger files and finally the bigger files, we end up with this rip. So, we’ve already explained that. So, now let’s just talk about how do we do a Type 1? You might remember, I gave a show, Show 49, last year about deep shape.

    These principles all continue to build, don’t they? So transportations, you have to have an idea clinically, can I develop deep shape? And that means look at your radiographs, look at your CBCTs and look at root bulk and form. If you have a big, bulky root and you have a lot of circumferential dentin, you can take bigger instruments in and try to capture not only the physiologic terminus, but try to capture everything. But you have to get shape behind the terminus, so you have to have enough root in here to do all that, right, so let’s take a little look at how we might do that.

    Clinically, ask yourself, is it a 20 down there, take a 20 in. A 20 might bind in here, but it will be a complete floater down there. A 25 might be loose, a 30, a 35 and a 40, and finally, you might get something that binds here, you know, the flutes of the file might bind in here like this, and you’re thinking it’s a 40 down there. Then ask yourself, where’s the 45? If the 45 is way up here, it means it’s still pretty parallel. You really want to get 20, half a millimeter back, 25, one millimeter back, okay, half, half, half, half, half, one, one and a half, two, two and a half, three. That means you can mentally see you have deep shape and you can pack into resistance form.

    So, you might have to take the foramen that was ripped up quite a bit, remove more dentin, of course, in the apical one-third, to see if you can get some deep shape. At some point, don’t mutilate the root. That means it’s a Type 2, we have to use a barrier technique, or we might even do surgery, and I mentioned that already, orthograde.

    So, essentially, when you look at these shapes, you’re looking at this whole root, and you’re asking yourself do I have enough root in here, enough bulk, where’s the furcation and do I have a big con cavity and do I have to worry? But you can make your preparation bigger than would be Ruddle ideal, cause for me, it’s usually about a quarter of a millimeter if there is not resorption or some kind of an iatrogenic over-instrumentation.

    If you saw that last case and you saw how big it is, look at this case. Now I’m showing you – I’ll show this case later, because I want you to notice this is a Friday emergency. It’s just before 5:00 p.m. and the dentist that refers it says, “I had a hot tooth. The patient came in and they’re a little swollen and they’re in a lot of pain. The tooth is pushed up in the socket and I opened it for you, but I noticed some bleeding and I was a little surprised because it was a necrotic tooth with an abscess.” With an apical abscess. And we have some breakdown in here too, but what you notice is this.

    So, when the tooth was opened and he saw blood, it’s because blood is coming through a perforation. And then he said, “But I did find all the canals. I worked on the distal and I got it open for you, Cliff. It’s going to be now more straightforward.” I would prefer him just to send the case over and not do anything, because now I have a furcal perf – we’ll talk about perforations another time, but I want you to really notice, this canal apically is kind of going out like that. It has reversed apical architecture, so when I open this tooth up – I won’t talk about the perf repair, I grabbed a 20. That 20 was sloppy, went to and through. I grabbed a 25, a 30, a 35 and a 40. Well, they were binding up in here where it’s restrictive.

    So, the idea is can you open this up and can you open this up so you have narrowing, cross-sectional diameters so you can pack into resistance form? So, notice the furcation. Here we are two years later, here is Ruddle’s repair, the bone is nice and tight, complete osteogenesis, osteoenductive, it repaired, and then you can see that I was able to get a little shape above the terminus, right in there. This is like a little puff. So, I was able to get a little increasing taper, so I was packing into resistance form, Type 1s.

    So, Type 1 transportations can be managed if you can get shape above not only the physiologic terminus, but the rip itself, so the terminus plus the tear. If you can do that, then you have a good chance to handle it conservatively. I think we’ve seen this case before in another example. A lot of times these retreatment cases, you can pitch them towards one thing or another. But in this case, this is a big silver point. It’s a sectional silver point technique, and I’m guessing the foramen is probably an 80.

    I never said this, but I can pretty much, if it’s less than or equal to about a 60 at the terminus, I can pretty much always handle that case with no barriers and without any surgery, because I can pack into about a 60. When you start to get to about an 80 or a 90 or 100, I have no chance because there’s a limitation. You can’t just go like this and say yeah, I got taper, but you blew out the root. So, we have to have some common sense, and in this case, we can come in with a Hedstrom, we can use a solvent, remove laterally lateral sealer that was in the condensation technique and then now there’s a space, and when there’s a space, we have a place to put a file.

    And a Hedstrom is very good at grabbing that silver point and retrieving it, so that we can still get hydraulics. We can still get increasing tapers and we can still pack with a lot of intentionality enough to get one, two, three, four, five, six, seven, maybe seven lateral portals of exit, seven P-O-E’s, portals of exit. So, that’s fun, and that’s a case where if it got a little bit bigger than that I’d probably have to think of another idea.

    So, the pre-op and the post-op and you can see we just were able to get a little bit of taper, and we had some taper here already with the laterally condensed gutta-percha, so it was really just get this out – it was really disinfection that we had to focus on, not so much the preparation.

    Last case, this is a case that has internal resorption, it’s going to be a long access up to the gutta-percha. If you look at the end of the root, you look at the incisal edge, we’re going to drill more than half the length of the tooth to get there, so be careful. Somebody else already got off axis, so it’s already bigger than I would like, and we don’t make our accesses that big in today’s world, do we? In fact, Ruddle didn’t make them that big back in the 60s and 70s.

    So essentially, once you get this gutta-percha out and do a lot of soaking and bleaching, and I’ll show this case later. I’ll show it under perforation. This was a facial perforation, a facial perforation. We can fit our cone, because I have a little taper above the terminus, and that allows me to pack up in there and get 2,000 pounds per square inch sealer hydraulics and drive thermal softened gutta-percha and sealer up against those dentine walls.

    And I want to talk about this lateral breach. This lateral breach right here is huge. This is probably greater than 100 file. That would be a 1.0 file. That’s probably more than a millimeter easily. And it even has a little taper here and it has a little taper there, so even that warm gutta-percha is moving into a little bit of taper towards a more constricted lateral portal of exit, and that allows us to keep our gutta-percha pretty much entombed inside the root of the tooth.

    Okay, in review, there are three types of transportations, Type 1, Type 2 and Type 3. Type 1 represents a rather minor movement of the physiologic terminus to a new location on the external root surface, so if we can get shape behind the terminus, we can pack with intentionality. When they start to get bigger than what is reasonable, and we can’t just blow out the root, then we have a Type 2, and we’ll talk about that another time where we use barriers and pack against the barrier, or Type 3 where it’s a massive movement and it’s going to require surgery to actually effectively seal the terminal aspect of the root.

    I hope you get pretty good at this and you can start in right now today because remember, retreatment, you can do it. See you next time!

    CLOSE: Ruddle Flashback – Visit to the DMZ


    Okay, so we’re going to close with another Ruddle Flashback, and this time, we’re going to flash back about 30 years to when actually both of us visited the Demilitarized Zone in South Korea. So, this actually had come up in my own household recently, and when I was talking about it, I just remember how blown away people were that I had even been there. And actually, my dad brought me there when I was about 20, 21. So, why don’t you tell us. How did we even have the opportunity to even go there?


    Okay, so many years ago, I got a call from a guy named Dr. Joe Moon. He was a prosthodontist at the University of Southern California. And he said he had an interesting patient and he wanted me to take a look at some X-rays, would I be willing to look at a few full mouth panels? So, the X-rays arrived, I looked at them, and I looked at them and gave him my opinion. And then he said, “Would you be willing to retreat these teeth?” because I was seeing 14 teeth that were failing endodontically. And all the teeth were there but there were 14 failures.

    And I immediately was thinking, well maybe it was subpar dentistry and, you know, maybe… blah, blah, blah. Anyway, it turns out that all the treatment was originally done by an endodontist in New York City, in Manhattan, and then when those failed, he was seen by an endodontist in Southern California, and got more treatment. And so, I was the third endodontist in.

    Long story short, I saw this patient as my only patient, that was part of the requirements, in the month of December, and when I was done treating my patient, his name was Kun Hee Lee, and he was – his father started Samsung Electronics, and when he passed away, Kun Hee became the sole owner of that enterprise. And so, he invited our family over as his guest to visit Seoul and spend one week in South Korea and seeing some of the things that he orchestrated for us.


    Okay, so then one of the – we did a lot of stuff there, and a lot of it was amazing and we could do a Ruddle Flashback probably on each thing we did, but one of the things we did was we went to the Demilitarized Zone.


    Yes, every day there was these excursions, as you just said, so a limo came and picked us – our family up, and we were driving north, and it was only about 45 or 50 minutes as I recall, through beautiful land and hills and it was amazing, very different than California or whatever I’ve seen. And we arrived at more or less the 38th parallel, which is about a 165-mile band that goes – cuts Korea into a north and south.

    And we arrived. And we did several things, I won’t go into all that, but the thing – I’d just like to say three things. We got to go in an area that was really tough to get to, even if you, under normal conditions, maybe you’d like to say something right now about it.


    Well, I just – during that time, there was high tensions between North Korea and South Korea, so I guess sometimes they open it up for – you can go book a tour there or something. I don’t know how hard it is to get in. It was completely shut down when we went, because of the high tension. So, that was, you know, already interesting that we were the only people there. And I do remember that they told us, and we were in that little lookout place, looking across a big valley, over to North Korea. They said, “Do not wave your arms around, keep them down,” like it was serious.


    No sudden movements.




    So, the three things that I’ll mention is there was the Bridge of No Return, so when we were standing up on this escarpment and looking down at this vast valley and the river, we can see this little bridge going across, very famous, they can Google it, the Bridge of No Return. And that was fun to see and exciting and to hear why and all the history behind it.

    And then there was the propaganda. I’ll never forget it. There was these towers out in that valley and you could see the Korean flag flying, the North Korean flag, and it was like, “Come to North Korea, the land of the free.” And I remember being so amused – well it was 30 years ago, so I was younger, but I thought how amazing, this is the land of the free, I don’t want to go there.

    Anyway, then that was the second thing, and then the incursion tunnels. And there are three pretty famous ones that our guests can Google, and two of them you can book tours through, but they have to have a lot of State Department background checks and stuff, but we got to go into one of those three, and we got to go several kilometers under ground into North Korea where they were permanently cemented off. But that was a thrill, and we got to see things that normally in my life I’d never see.


    Yeah, no, I remember going down into the tunnel and it was basically the size of a military jeep to drive through. There’s – I mean and it was just exactly that size. I mean there was not extra room above or out to the sides, and I do remember there was water dripping from the ceilings and the walls, like ground water. It was kind of eerie.


    Well with their tensions, they’re always doing these exploratory tunnels, and always from the north to the south so they could pop up, but back to your point about wide enough to take a certain kind of a vehicle. I had forgotten that it was a staggering number of men that could get through that tunnel per hour if there was a full-on incursion of the south. It was like tens of thousands.


    Yeah, I remember them saying like thousands of jeeps could get through here in a certain amount of time. I don’t remember the exact numbers, but it was very impressive.


    So, yeah, that was out little trip up to the 38th Parallel and, of course, you know, with history and in the last 30 years we read about that area and, of course, to you and I, it has more significance than just reading about it in the paper. We were there.


    You know, I actually – I mean I know that we went there, but I actually have not thought about it that much until probably within the last couple months and sometimes things happen in your life and an opportunity comes up and you’re going through it, but you don’t realize until way later like the immense impact it maybe had on you in your life and how you view things. So, that was interesting.


    Good memory.


    I was also wanting – one thing that was interesting was when we went there, we didn’t have any cell phones. Cell phones were not a thing. So, we weren’t taking pictures of everything and I mean we were just completely in the moment.


    You would have been shot dead if you did.


    I probably wouldn’t even be allowed to use a cell phone if we had them.


    But that’s interesting, no cell phones.


    Yeah, so it’s interesting when you think back on some of these experiences you’ve had before cell phones that you have no pictures of or anything. It’s like did they really happen? I guess they did.


    Well maybe I should just say in closing then to the audience, maybe sometimes put your phone down and make indelible, permanent memories in your mind that you could call into play as long as you could remember to access that information.


    Right. Well okay, that’s a great story. Thank you. And see you next time on The Ruddle Show.



    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

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