Treatment Rationale & Letters of Recommendation Review of Why Pulps Break Down & Getting a Helpful LOR

This episode opens with Ruddle revealing a couple of his favorite Michael Jordan quotes, following the inspirational airing of The Last Dance earlier this year. Then, Ruddle reviews the rationale for endodontic treatment, focusing on why pulps break down and the formation of LEOs. The next segment is a discussion on getting the most helpful letter of recommendation. WHO should you ask? The show closes with another Ruddle Flashback, this time the story of when Ruddle nearly cut off his thumb.

Show Content & Timecodes

00:08 - INTRO: Michael Jordan Quotes
06:39 - SEGMENT 1: Rationale for Treatment
27:53 - SEGMENT 2: Letters of Recommendation
41:01 - CLOSE: Ruddle Flashback – Skillsaw Accident

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Downloadable PDFs & Related Materials

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“Endodontics 101: Back to Basics”
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Much has changed in global endodontics over the past 40 years and a great deal of this change has been driven by the relentless introduction of new technology...

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A volcanic eruption best characterizes endodontic treatment in recent years. This massive, upward thrust of clinical activity can largely be attributed to general dentists and specialists who are better trained. This evolving story is dependent on...

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"Endodontic Diagnosis"
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Dentists are trained to thoroughly review medical and dental histories and perform comprehensive extraoral and intraoral examinations. Yet, in spite of these efforts to optimally serve patients, the dominant clinical reality is...

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"Predictably Successful Endodontics"
Jun 2014

Dr. Herbert Schilder used the title, "Predictably Successful Endodontics," to describe many of the lectures he gave over about a 40-year timeline. In the most simple and direct way, these words promise longterm treatment success that is not only possible, but attainable...

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"Radiographic LEOs: Significance of Location"
Apr 1987

Dental radiographic examination frequently depicts radiolucencies approximating root surfaces. Apical radiolucencies in particular tend to cast suspicion on pulpal health and are often associated with endodontically involved teeth...


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INTRO: Michael Jordan Quotes


Welcome to Season 3 of the Ruddle Show. I'm Lisette and this is my dad, Cliff Ruddle. Are you pretty excited about this upcoming season?


I'm very excited about this upcoming season. Today is the first shoot day of Season 3, but Lise and I, we've been working for some weeks behind the scenes planning the season, lining up some guests, taking some topics that we think will be relevant. We're going to do a little surgery. Different things this season and it'll be really fun, so yeah, I'm excited.


Yeah, I'm excited too. We're going to start off our first show today with some Michael Jordan quotes. 2020 has been a bit of a rough year, but one of the really great things about it was The Last Dance that aired earlier this year; it's a documentary on Michael Jordan. And Michael Jordan had some pretty inspiring quotes and we're both pretty inspired by Michael Jordan, so we chose a few quotes that are our favorites.


Yeah, we've got quotes; all kinds of quotes.


I'm going to read this one that my dad chose and then he's going to tell us why he likes it.

"I've missed more than 9000 shots in my career; I've lost almost 300 games. Twenty-six times I've been trusted to take the game-winning shot and missed. I've failed over and over and over again in my life and that is why I succeed."


Well you know, I love the quote. And because I always go too long, I could just say don't be afraid to make a mistake. You know mistakes aren't good; they aren't bad, they just are mistakes; are the stepping stones to greater success.


Yeah, and I guess that if you're missing that many shots, you're probably making a lot of shots, too. So you're getting a lot of practice in and the more practice you get, the more successful you are.


Yeah, what she just said is what we all know. Are you looking at any situation as the glass is half full or half empty? So Jordan is focusing on what didn't go well; but your point is huge because he only turned out to be probably and maybe not even arguably the greatest player to ever play. So great players don't always have things work well.


Plus the more you fail, then you get kind of used to it and it's not so devastating. So then you're brave enough to keep trying.


Well what he doesn't say is Michael Jordan always expected to win. And Michael Jordan always knew when he took a shot it was going to be nothing but net. That's the mentality that we have clinically isn't it?


Okay, read my quote now that I chose.


Okay. Do you like that? Okay. "Always turn a negative situation into a positive situation." What does that mean to you?


Well when I was looking at it, I was like okay, well it's the same situation. It's not like it magically is changing. But I think it has to do with our perspective and how we look at it. Like we could choose to focus on all of the negative things in a situation and how trying they are for us. Or we can look at what positive is coming out of this; what am I learning? And I know a lot of the things that I thought were negative in my life that were happening at that time; I've now looked back on them later and have thought like wow! I'm really actually glad that happened to me because I wouldn't be the person I am now if that didn't happen to me and if I didn’t learn the things I learned from it.


Well I need to stay close to the clock. But I could tell the whole group about your China tour that was aborted because you blew out your knee in the dojo. But that turned out to be really something important and you went on and got your black belt. So there's an example where you could have just quit and said it's a little bit too tough for me.


Well I actually did go to China with my leg brace and everything.


Well of course. And that's another story of perseverance, dedication and honor.


I'm going to read now the last quote that my dad chose. Here it is:

"The minute you get away from fundamentals, whether it's proper technique, work ethic or mental preparation, the bottom can fall out of your game, your schoolwork, your job, whatever you're doing."


Okay. I get lots and lots of questions, as you know, and they come from all over the world, and it's about people who have not ever learned the fundamentals. And so can you imagine that colleague is practicing every day and before they get to some teacher that can help them, they keep continually making or having certain kinds of upsets. So it's important to find a teacher – your teacher, one that you trust, you can work with and feel good – and then work on those fundamentals. Because perfect practice makes perfect play.


Yeah. When I was looking over all these quotes and I saw this one, I knew you were going to choose it. Because you are always going on and on about the fundamentals win the game; focus on the fundamentals, the fundamentals. It's just really you beat that drum a lot.


I could sit here and spend four hours talking about the three quotes that we're supposed to do in five minutes. But just one last thing. The players' championship was this last weekend and it was for the season; the best golfer of the season accumulated points. And so it's four days, four rounds. Between round 2 & 3 a certain player was not finding the fairway with regularity and the ball was slicing. They looked at a lot of film – fundamentals – and then they realized he was standing about 2 inches too far away from the ball and therefore he was hooking the ball. So he made the adjustment and he won!


Okay, great. All right, well those are a few of our favorite Michael Jordan quotes. Hope you liked them. And now we're going to get started with our show. We have an exciting show for you today. So here we go.

SEGMENT 1: Rationale for Treatment


Today's lesson is on the rationale for treatment. Now everybody knows that we look at radiographs and we can see lesions of endodontic origin, and for a lot of you, that means indication to go; proceed with endodontic treatment. Others of you will do your pulp testing and the whole thing that we've talked about in previous seasons and shows. But today I'm going to just talk about something that will help you more as a thoughtful clinician to treatment plan for no surprises.

So let's look at the situation at hand. We have teeth in the mouth, they're in the periodontium. We have papillas, we have periodontal ligament space, and inside the tooth, we have a root canal system. Repeat after me: system. How you communicate is how it is, so if you speak about systems, you're thinking systems. If you say I'm treating a canal, you'll be thinking very simply one single little canal with a turtle opening.

So everything's fine, and for the tooth, it's probably never healthier than during its formative years during tooth eruption. And for many pulps, after they erupt, it begins to be a downhill slide, because things happen. Trauma. What kind of trauma? There can be trauma from sports injuries; that's the trauma we usually think about. But trauma can come in the ways of orthodontic tooth movement; it can come in caries; it can come usually as an example of multiple episodes of repeated dentistry. And every one of those episodes of dentistry is a little bit of trauma and that trauma is cumulative and it's additive. At some point our pulp hits a tipping point. Season 1, Show 7; we talked about diagnostics, okay? And I'll refer you back to Season 1, Show 8; and we talked a little bit about breakdown. And then we talked about the business of endodontics in Season 9; 7, 8, 9. Go back and watch those shows in Season 1 to see about how this will relate to even the business of endodontics.

So we get going here and we start thinking about today we've got a virgin tooth; everything looks virgin so we do our exam; everything's fine, we make a note that everything seems healthy. Are you doing a baseline on all the pulps when you do pulp testing? Let's take a look, and I'll get you oriented. We're looking at this little zone and in that zone, we can begin to see what happens. You have a normal pulp, okay; what is a normal pulp? Well first of all, a pulp has a lot of connective tissue. We have a lot of connective tissue. And this connective tissue has a lot of elements, stem cells, but they might be called really – these little things you see in the connective tissue, each one of those is an undifferentiated mesenchymal cell. And these undifferentiated mesenchymal cells can be called to action. Let's take a look how they might be called into action.

So a patient comes in, you do your examination and you take a bitewing or a well angulated periapical film which is just an extension of a bitewing, and you notice there is some occlusal decay. You might have caught this clinically with your exam with an explorer. You might have found a soft spot or you might have been able to read it and interpret it. So when you see that, what does any good dentist do? Oh great! Let's get our sleeves rolled up; we're going to go in; we're going to do some work! And we're going to make a sick person well.

So we go in and we do the restoration. And let's come back and look about this area and see what the pulp's doing as a response to cleaning out the caries, the bases, the liners, and then the composite itself. And so all this is traumatic. I want you to keep your eyes on the pulp chambers. Pulp chambers are usually a little bit supracrestal. Okay, so the pulps usually move up into the chamber and the chamber is in the crown of the tooth itself. So keep your eye on the height and diameter of the pulp chamber. Oh I just love this feature!

So you do all that. Well what you've noticed is your undifferentiated mesenchymal cells, stem cells, they're pluripotent; pluripotential. They can do different things. In the case of an injury to dentin, they undergo mitotic division; they cross the cell free zone of Weil. They cross the cell free zone of Weil. So I'll go back – we'll actually go back one slide – and I want to show this a little bit more. So you've got your undifferentiated mesenchymal cells; you've got your odontoblast – and see how they're all lined up – and they are elaborating reparative dentin. So right in this little zone you are getting some – you see reparative dentin and you see a conglomeration of all those cells as a response to the dental procedure.

So when you look at another episode – so little Johnny comes in, 6 or 7, gets the Class 1 – making this all up, it's psychodrama role play. Now he comes back, he's 10 years old, and there is now a proximal carious lesion. What does any good dentist do? They clean it out, the make a Class 2 – in this case it's an MO – mesial occlusal – and we can look and see what happens. Well first you notice the pulp got a little bit smaller in diameter and it began to recede and pull away from the injury. Well, this is why when people go home they say you know, before you touched my tooth I was fine and now you put a little restoration in there – and imagine if it's metal versus composite and all that stuff – and now when I drink cold liquids; boy, I got to put my tongue over that tooth and sneak the water around the other side. That's because your pulp is screaming. Notice all the inflammatory cells. So your blood vessels have gone from initially vasodilatation to vasodilation – or I'm sorry, vasoconstriction to vasodilation – and so lots of blood's in there carrying all the polimarvo neucoleucocides – your round cells, your histiocytes – you're mounting an inflammatory response to overcome the injury.

Well that would be fine; that could probably even calm down and heal. But remember I said the pulp is never healthier than during its formative years. So all these little procedures are like a little kick in the seat of the pants of the dental pulp and those injuries are cumulative. A lot of dentists say around the world "I love calcification!" They say what do you think Cliff? You like calcification? Calcification isn't good, it's not bad, it just is. It's a response to the pulp. What we should all appreciate is that as your pulp is narrowing and constricting, as it's pulling down from the irritant, there's less vascularity. And that means there's less opportunity to bring in the defense cells that will actually repair the pulp. So calcification isn't good and it isn't bad; but remember, if you're doing another dental procedure on a pulp that's already receded and a little bit more restricted in its diameter, there's going to be a bigger opportunity to create an endodontic dilemma.

So loss of inflammation. Well wouldn't you know, Johnny trots back into the office – he's now another year or two down the line chronological – and wouldn't you know, the assistants bang out a new X-ray and we see on this radiograph another penetrating lesion. It's caries; there's microbes. And what I want to start talking about is the dentin. When you're in the dentin, you should recognize that it's porous. It's a porous material and it's comprised of dentinal tubules. And there are tens of thousands of dentinal tubules per every one square millimeter. Tens of thousands of openings like pipes that communicate right down into the pulp proper. So when you're up here doing your work and you're taking this out and combining it to make an MOD restoration, remember there's direct pipelines into the pulp and it continues to want to pull down and get away from the injury. Whoa! Did you see that recession; how that pulled down? It's a protective mechanism.

Now you notice that we're just approaching the level of the crest of bone on the adjacent sides. You notice a lot more vascularity over here on that virgin tooth; much, much better capacity to heal. So when you begin to look at this drawing, what you're noticing is when you're doing the grinding and you use the burrs and you're using the air, and then you're putting in your monomers and your polymers and your bases and your chemicals, you are walloping the pulp, da-da-da! Okay. So those odontoblastic processes, they extend up into the dentinal tubules. And when you're doing that air drawing, you are aspirating and sucking the dentinal tubules – the odontoblasts right up into the tubules. And now you have the whole cell body lying in the tubule dead. You've put your restoration and you're done, the patient went home, but you have thousands and thousands of tubules that are filled with necrotic tissue. And this necrotic tissue doesn't stay resident to the tubule. In fact it begins to egress and leach back into the pulp proper. And of course, that's long-term irritation.

Okay, so you begin to see that there's consequences to repeated episodes of dentistry, there's a biological response to those injuries, and so what's happening is a lot of dynamics is occurring inside the root canal space. So these are called dead tracks. They're dead tracks and those dead tracks are going to hold organic material that's going to come back and probably be a problem. Well, the dead tracks continue causing irritation, but the patient keeps living, they keep their same habits. A lot of times they don't floss as much as they should, they don't clean. So what is the gift that keeps on giving? All the restorations begin to break down over time. There's different [inaudible] of expansion between materials; things move a little bit. And oftentimes you're in there saying what? The patient's 18 years old, 19, 22, and you're going you need full coverage. I see another problem. And what we do is we put a casting on. And once we put a casting on or a tooth colored restorative, that's a tooth that's had an amazing amount of work.

People rarely start off with their first restoration being a full crown. Unless you're playing basketball, you're down in the paint and you get an elbow; okay, you chip or break a tooth and they might have to put a crown on that virgin tooth. But generally it's a Class 1, a Class 2, then it's a coverage issue, and all of a sudden – the dentistry has been done beautifully. It's been done beautifully, but there's a biological price to pay. And these dead tracks that I told you about where the organic material leaks back into the pulp – look at this; what do you think this is? For $500 can you tell me what that is?

Well that is an abscess. But the abscess has been walled off. Do you notice how it's been superbly walled off and it's pretty harmless at this point? The rest of the pulp looks like the connective tissue is good. You can see no really big inroad of inflammatory cells. And so people walking around like Cliff Ruddle right now; I've had several crowns placed in my mouth. I've had a few root canals done. But I know some of those teeth that were crowned even 10 years ago, 5 years ago; probably I have a pretty good chance of eventuating a future root canal. And an abscess if it's walled off might lie there for years of a patient's life; but what if you get recurrent decay under the margin? And how often do you out in the real world of dentistry repair/replace crowns; existing crowns; crowns that you might have even placed yourself?

If you look at insurance charts – this isn't great dentistry I'm speaking about – but if you just look at actuarial charts from the insurance business, they will pay a doctor every 5 years to do a new crown in California as an example. Which means the life expectancy, the half-life of a crown must be about 5 years. I've seen many general dentists in my community refer cases in to me and I've see 30-35 year recalls; the same castings on the tooth. So crowns can go a lifetime. But the practicality in the real world; they don't last here that long.

So when you see this abscess, recognize that – you won't see it of course – but recognize from the histology and these beautiful histological slides from Stanley – we got them back in the '70s when we were residents and I've used them many times in the world. Now you know dentists don't really like to watch breakdown and disease flow because they want me to teach them patency or how to negotiate a canal, or how do you shape, or tell me about 3-D disinfection. I want to know how to fill root canal systems because I'm a big guy and I want to do a good job! You're going to do a better job if you understand the pulp, the physiology and health and its pathogenesis.

So if we continue on, breakdown occurs coronal apical. The first lesion that would form theoretically is the one closest to the injury. The one that we see on the radiograph is usually apical, so that's why kids all over the world they like to go – you say hey, give me an assessment of your endodontics. And they'll hold up an x-ray or a panel and they'll say "looks good apically". No! Start interpreting your films periradicularly. Look for little bulges and dark areas and shadows and lucencies, radioluciencies in that trabecular bone. It's not so easy to see these little lesions laterally on a film and by the time you see them, there's been quite a bit of destruction and more osteoblastic activity than you probably imagine.

I've said this many times in my career, but those who do surgery – and we're going to get into surgery; we're going to get into a lot of surgery in the shows ahead across the years. But anyway, no surgeon ever went in and operated and said gee, the lesion is a lot smaller than it looks like on the radiograph. In fact, when we get in surgically we're going wow; it looks really big. It looks a lot bigger than that 2-dimensional picture of that 3-dimensional object.

So the disease flow is crown down. The lesions form adjacent to the portals of exit. I'm going to go back one click. But the breakdown then is crown down as we've said. You're going to have the egress of irritants along these anatomical pathways, and that's going to give rise to Lesions of Endodontic Origin; LEOs. LEOs are not germane to the bone. They do arise in the bone. It must be understood that lesions form adjacent to the portals of exit. And the reason the lesion is in the bone is because there is the egress of irritants.

So we've talked about root canal systems – say systems – we've talked about LEOs; and now we're going to talk about all these portals of exit. So we've got LEOs and we've got portals of exit. So lesions form adjacent to portals of exit. And make that connection; because on a well angulated film, you're going to see about 50 microns, okay? And about 50 microns means everything's smaller and you don't see. So we only see things about 50 microns and bigger. So really have those assistants take well angulated, use aiming devices, and you'll start picking up vertical canals, vertical lesions. You'll start picking up lateral lesions. It's really something. You'll become a better diagnostician.

Remember Season 1, show 8? We talked about the pot of gold. We said that at any given time – if you'd been out about 5 years, you probably have a million dollars of undiagnosed treatment that you have simply not observed. Remember, you're good at finding the toothache, right? You're pretty good at isolating where are those patients' chief complaints and symptomology coming from. But are you finding the asymptomatic teeth; the ones that patients aren't complaining about? Well?

So you make your access; we've talked about this and we'll talk about it more. The access is critical; the first mechanical step. That gets you inside so you can find an orifice or orifices. And then we need to skillfully catheterize the canal; we need to secure the canal. A secured canal is that canal that has a smooth, reproducible slide path. That's a canal you can put a mechanical instrument in. That's a canal that can be shaped. A canal that can be shaped can be flooded with reagent, and that reagent can be – in today's world it can be activated so that it penetrates, circulates and digests tissue from the uninstrumentable portions. We don't instrument much of anything. Our job is just to make a smooth, tapered pathway to link, flood it with a reagent, activate it, and through bombardment, our reagents can work where we aren't clever enough to work. So this is a very forgiving technique.

And of course if you've cleaned out the lateral anatomy, it's quite easy to compress thermal soft and warm gutta-percha into vacated spaces. Remember, if you're not seeing anatomy on post-operative films, and you're doing all the things that we've been talking about over the decades, then probably you're blocking the lateral anatomy or you're not using devices that can help you clean in a more forgiving way. So think about it; train up. Education is about continuous training. And if all the time you're working a little bit short and you're always pulling up a little bit short, and then you notice the lesions really don't heal; make the adjustment. Take all the pulp out. Don't just flirt with part of the pulp. You know? Either take it all out or don't. So those are all decisions that we make.

So finally, we know that if we eliminate the contents of a root canal, like the extraction, then we know the bone will repair. And it's inevitable that endodontics has the capacity, by eliminating the irritants, to initiate osteoblastic activity; and watch repair, it's quite fun.

So we typically recall patients at 6 months, one year, two years, five years. And then I tell the patient at five years, it's every five years as long as we're both alive. Do you agree? And I get the commitment. Because I want to see things at 30 years and 35 years. We're starting to see some recalls at 40 years. It's exciting to see how predictably successful endodontics can be when it's properly performed.

SEGMENT 2: Letters of Recommendation


Today we're going to discuss letters of recommendation. It is not uncommon for you to get requests from dental students or clinicians, who you have never even met or maybe you only met them once, and they want you to write a letter for them. Perhaps they're thinking that you're relatively famous in the dental world and that you have some influence, and a letter from you is going to be a hole-in-one, or a touchdown, a homerun to use some sports analogies.


Getting the last shot.


But if you really want the letter to be helpful, there are some other issues to consider besides just how well-known the person is that you're asking. Don't you think?


Yeah, there's lot of factors that go into it. But the way you set this up, that's how I get a lot of them. So I would say there's two kinds of people. There's people I know very well and they would like a letter of recommendation; and there's a lot of them, about half of them, they were a face in a crowd. So I spoke all day long and they were out there, and I could see their eyes and they were connecting, and their love and passion for endodontics grew during that day. And they're so inspired that it is something they want to catapult to even more. So I'm flattered when they ask me, but sometimes it's like oh geez; I don't have enough context.


Well I know I've heard you sometimes say that you probably aren't the best candidate to write the letter for them because you don't know them very well. So who would you recommend that they ask?


Okay, that's really the great question. If you're out there – and let's set the context – it could be a college student who wants to get into dental school. We've done a lot of work in that area – you and I have because she writes them. I have little input. There is the graduate from dental school that wants to go on to pursue post-graduate training. There are trained endodontists that want positions at different schools. And I get letters, especially from overseas dentist endodontists, and these individuals would like to get to the States and they'd like to pursue research or clinical work or things like that. And so that's sort of the people that I would –


I know you've also written in to nominate people for awards as well.


Okay. So back to your question, though. It's really important that the letter come from somebody. So if I'm writing one for you, you would want me to write the letter because we have a context of where I was maybe your professor in college. Maybe I was on the floor in dental school and I was an endodontist on the floor and we did a lot of cases together over your four years. Maybe I know you as a dentist because you've come and taken my course like four times and now you want to go to Endo School.

So the letters that would be most important would be from somebody that knows you; somebody that actually has known you for many, many years. Because getting somebody to write a letter, I don't care if it's the most famous person in the world, the first thing – the Chair is at the school and he's reading this letter and he goes well does Cliff actually even know this candidate? And a lot of times I would have to say in the letter that they really seemed eager; they were very, very passionate about pursuing it. But I can't say the really important things that are going to get you in. I don't know much about your integrity, I don't know much about your training, I don't know much about your skills, I don't know about your honesty, I don’t know if you're a team player. So you want to get people that write letters like – it sounds crazy, but maybe a religious person that has known you across your whole life and they can attest because they've seen you hopefully every week, you were at church, synagogue, temple, somewhere. Maybe it's a college professor that you did really good in physics or chemistry and they really see this light inside you that can be lit and you can go far. It could be maybe the Dean of a school that saw you; maybe you flourished at school, dental school or college or whatever.

So you want to get the right person; a person who actually can speak for you because they know you. And they don't just know you as a student on campus, but maybe you were in a classroom, maybe you got A's, maybe you did some projects that were over and beyond the class and they saw all this.


So if you're applying for like a dental position, I mean it's nice to get a letter from someone in the dental field but you're saying it's not necessarily required. Because even a clergyman or somebody else in your life can speak a lot to your character and your ability to work hard and that kind of thing. So someone that just knows you and can talk about you in a detailed way.


And it can't be your mother. You just can't have your mother write the letter for you. I know she'd love to and you'd love to have her write it, but it's just not going to work.


Okay, so say you agree to write a letter. Do you find that you think you should only be focusing on the positive? Or do you think you should maybe point out something that might be of concern or negative, perceived as negative? Or should you just stick to the positive?


This is the art of the candidate getting the right person to write the letter. If I see that you as an example every time you're in a group – so let's say we did some drills and we were in the workshop part of the course and you always work alone. I never see you talking to other students at the breaks; you don't have lunch, you eat at a table by yourself. That's a person that might not work well with others. And a lot of times the Chair wants those three letters to come in – they usually want three letters; five is too many, three is plenty; it gives a perspective from different walks of life. So maybe choose the person that's going to write the letter; somebody who knows you from a certain context, somebody who knows you from a different context, and somebody that can even speak about other things you wouldn't normally see.

So back to these letters. I think it's important to have somebody write the letters that can really know you and not just your face in the crowd. That's the most important thing; familiarity. And if you write something – if you see something bad, I think I have to say something about it. Because my reputation is also on the line and a lot of Chairs know me, they trust me, they respect me, and if I write this glowing letter and this person isn't that kind of a person then I've let them down, I've let the school down, and I haven't been honest or completely accurate. So if somebody asks me for a letter they should know that I might write the good and the bad. But of course if somebody's going to trust me with a letter I'm not going to throw them under the bus, but I think I have to give a pretty good glimpse. Sometimes the way you're negative is you just might say I don't know the candidate well enough to be able to speak about all aspects of their character.


Or if it's something like some type of learning disability. Perhaps you mention that, but you also talk about how they've overcome it and how it's made them stronger. So I think if you say something that's negative but then talk about how they have risen above it that's also, I would think, shows that they're able to persevere.


Shares a lot of stories of redemption.


Okay. So when you're writing the letter do you follow any kind of general format?


Okay, so when I was younger – this means 30 years ago – I used to write every letter I was asked to write. Because I thought somebody helped me, so at one time in my life there was somebody that broke out their pen or their typewriter or their computer, whatever era we're in, and they probably helped me out. So we all had help getting where we have gotten.

So I think it's important then that we realize that these different letters are helpful, but we need to be sure they're coming from the right people and we need to be sure that the format isn't too long. Chairs do not like to get pages and pages of oh my God! You know there's a lot of applicants. I don't know if you are reading this, the audience, but reading it means if you're looking at business models. But there are a lot of applicants every year to post-graduate endo schools; hundreds. Sometimes there might be over 1000 for two seats. So you want to stand out; the candidate needs to stand out. And I've talked to these candidates a lot about forget the letter; I can't write you a letter but I'll give you coaching in another way. And they'll say well what's that? Why don't you make an appointment with the secretary and see if you can just come by and spend a day at the school and watch the kids work. And maybe she'll even assign you – the secretary might assign you to a particular resident. And now you kind of hang out with that resident. You eat lunch with the resident; the conversations, the cases, the darkroom, all that stuff; you know in the old days darkroom.

So you can get a lot of information from seeing the students, but here's what's important. The students see the candidate. And oftentimes when it's all said and done the Chair – I've seen the Chairs do this. They'll walk in and they'll say well okay; I have reviewed all the applications and I narrowed it down to this one and this one. What do you students think? And the students oftentimes are the ones that do the final acceptance, because they go gee, when Lisette came, she was really fun. She was very interested; she wasn't arrogant. Because a lot of times – oh I took a Ruddle course; I went to Buchanan's course. They don't want to hear this, because it means like you already think you know everything. You need to be humble. I know nothing; I came to train at your feet; please teach me; I'm an open vessel – pour it in!


Yeah. I think that also if you're asking someone to write a letter for you, maybe you should know if that person can write a decent letter. Like are they good spellers; is it going to look professional? Because you don't want to ask someone to write you a letter and it ends up hurting you because it looks like they just scribbled it out without taking any time or thought.


When I stopped writing letters as frequently as I used to in the old days, I then put the assignment on the candidate. So if somebody – a face out of a crowd and they would be a lovely person, and they would want you to help them do something. So what I would normally say is write a 3-paragraph, 1-page letter. The first paragraph is an introduction of who you are and why you're writing. The middle paragraph is your qualifications and areas of interest outside of endodontics. And the last paragraph would be why you think you are uniquely qualified to help the profession and be a leader going forward to help other students. And then I would say write this; send it back to me; I'll Ruddle-ize it and put it in Ruddle words; and then I'll send it out for you.

But even then I got uncomfortable with that because I'm going well they're saying a lot of really glowing things, but I don't know what I don't know. So now pretty much I'll help them get into schools or appointments in other ways. And the other ways are maybe call up a Chair and just say you're going to probably get Harry; he's going to come by and he's going to have an interview with you. He's a great guy. I met him first in Venezuela, then I saw him come up to the States. He went to a Chair school and he got certified and trained. I'll do my stuff behind the scenes, but it won't be the official letter.


Right. I guess you do have to be careful about who you endorse. Because you don't want to endorse someone that's very flaky or whatever.


Maybe you'd endorse a perforator. Maybe a blocker or a ledger.


Because then it reflects badly on you, right? I mean if you endorse someone that doesn't live up to the high standard that you write about in the letter.


Yeah. You just really want people that are honest, work well with others. Kind of like what you need to be when you're a practitioner and you're interacting with patients from all walks of life. You've got to find commonality. You've got kids; I've got kids. You went to that school; I went to that school. You ski; I ski. My gosh, you like endo; I like endo. The more of these personal connections you can make, as in business, as in life; it's about relationships.


Yeah. Well thank you. I think we're a little clearer now on letters of recommendation. And I think that we also understand now that it's not only dental students who are trying to get into graduate programs that are looking for letters. You gave some other examples of when you might need a letter. And maybe some of you have been approached by others and you need to write a letter for someone else.


Or maybe some of our audience needs a letter.


Well thank you very much; good information.



CLOSE: Ruddle Flashback - Skillsaw Accident


So that's our show for today. We're going to close with another Ruddle flashback. You might remember last season we had this and I think you talked about some dentures flying out of someone's mouth.


Oh, Clem Daniels!


So now we have another story for you today, and this involves my dad nearly cutting off his thumb with a skill saw. So why don't you tell us what happened there?


They always pick on gruesome stories don't they? Okay, well I guess you were 10 years old and your sister was 8 years old, so it was about 1980. And I guess I should say I used to work on construction. So for many, many years before college – many, many years I worked on big jobs, little jobs, we built houses, we built commercial buildings in the Bay Area. So I've been around saws and power tools my entire life so I did not think I was the weekend warrior trying to do something heroic.

So we bought our first house. As you recall, we went from a condo to this little house in Montecito. And of course we had the worst house on the street, but it was the only one I could afford at the beginning of my career. And so it had a lot of potential though. It was a nice setting with a lot of potential.

So we had a leak in the roof, and I remember that perfectly because I went up to fix the leak and realized there's a view up here. The next weekend, the entire roof was off the house. And I stayed married. But Phyllis was a great helper and we did projects. And every – I mean in the long summer days when I got home like at 7:00, I could get another couple hours in. Every weekend, Saturday and Sunday, we were working on the house. Roofing and various projects around the house, not just the story I'm going to tell.

So the story I'm going to tell is I noticed there was a view up there on the top and I thought I'm going to build a little room up here and this is where I'm going to work on my lectures.


Not just any room; a hexagon shaped room.


Oh, right! Because there was the meeting of all the complicated compound joints where all the beams had to meet. Yes, that was great fun. She helped me a lot. I mean I had a little bib on her and she had her hammer and stuff, and we shingled the whole house.

But anyway, I needed to get up from the first floor to the second floor, so I put in two stringers and the stringers were 4 x 12. So 4 by about 12; they're big timbers and went on each side. Then I was using a saw to dado out slots to put the treads in; the treads are the steps that you get on up to the second level; and bull nose tread I might add, so very nice bull nose.

So I was cutting the stringer and I remember perfectly. I did not think I was taking a chance, but the saw bound and it jumped and went across my thumb. And it went through the tissue, through the bone, but I missed the neurovascular bundle which is in the webbing. So my thumb was just hanging down and it was bleeding. So I called for Phyllie, Phyllis, and Phyllis came running and got a towel and off we went to ER.

So long story short, the surgeon, John Chapel, who has been a family friend for like the last 40 years; he was available on the weekend. He came from his rose garden where he was trimming his roses – that was his way of getting away from it all – and he reattached my tendon and then I had a cast. So it wasn't too painful and I thought I'll just start practicing probably like Monday morning.


It was your left hand it happened to?


It was my left hand.


And you're right handed?


I'm a righty, but those who know me well, know that I do a lot of things endodontically with my left hand. I don't know if it's from basketball or what.

So anyway, I saw that first patient. We scheduled a patient; he's back; he's ready to go. So I had a little elbow cast below my elbow so I could move my arm. But you know, the casting around my thumb was probably 3 or 4 inches. So patient wants to know about it; we talk. And I knew the patient from a previous procedure. So leaned her back and as she was coming back I asked for the anesthetic, and I'm going to reach in and retract like we normally do with the off hand. And I realized my thumb won't fit. I can't get it in her mouth. Well I didn't think about that one.

So I said to my assistant

can you give me a lot of traction? So she reached over with the mirror as you're tracking, and I realized that I had no business treating patients at this moment. So I finally told the patient, you know what? It's dawned on me I'm not your guy. And she was very disappointed; not angry, disappointed. And I told her that I had another guy in the office who was my associate at the time, and nobody's ever heard of him anywhere in the world; his name was Steve Buchanan. So Steve was a champ in that he stepped up as an associate and he carried my practice for about six weeks.

So through all that – maybe you wanted to ask a question?


Well I'm thinking of my Michael Jordan quote: always turn a negative situation into a positive situation. So did anything positive come out of that?


You know what? It works perfect with our opening. I don't even know if it was intentional.

We had been teaching – I had been teaching for quite a few years. And when I say "we"; we brought groups in. Besides me going out, we had international groups coming in to Santa Barbara even in the '80s, and they were coming in to train. And so I realized I don't have any income. It was turned off. And yes, you can make a little bit off the associates' income, get a little margin; but it isn't going to pay for the staff, the rent, the supplies; it's not going to keep the business going.

So out of that negative, we said we're already in teaching. Maybe we should just on the proverbial accelerator of life push down and just offer more courses. So we went from having maybe one course a month, maybe one course every other month – because I was going out. I was practicing five days a week, I was flying out to give lectures, and groups were coming in. So now I didn't have any practice, so we decided maybe we could give two international courses or two courses a month. So we were doing about 20 to 24 courses a year. That kept my team together; we learned a lot about education that we would have never –


I think you started traveling a lot more also to give lectures.


It kind of opened up a whole thing. And it was just because the focus, instead of being totally clinic, now it was on what else can I do in the world of endodontics that I'm trained to do that I can still make a difference for others. So teaching really stepped up, I would say in the '80s. And of course I started in '76, so it definitely influenced my career.


Excellent; that's a great story. I really like how when one door – that expression, "when one door closes another door opens up.”




And you've just got to have an open mind and be able to recognize those opportunities.


So the next time you cut off your thumb damn near, remember the best is just ahead.


That's our show for today. 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

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


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s10 e01

Delving Deeper

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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


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Endodontic Surgery & Innovation

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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!


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Case Discernment & Lateral Repair


s09 e08

Fresh Perspective & Apical Divisions

Fast Healing & Irregular GPM and Cone Fit


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s08 e01

Endo/Perio Considerations & Recent Article

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s08 e02

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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

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special e06


As Presented at the John Ingle Endo Symposium


special e05


The Importance of Simplicity & Getting Back to Basics


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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


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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


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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

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Important Research Considerations and ProTaper Q&A


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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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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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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
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