Dentistry Uncensored with Howard Farran
Dentistry Uncensored with Howard Farran
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190 Endo Innovations with Rodrigo Cunha : Dentistry Uncensored with Howard Farran

190 Endo Innovations with Rodrigo Cunha : Dentistry Uncensored with Howard Farran

10/14/2015 2:00:00 AM   |   Comments: 1   |   Views: 463

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Stream Audio here:

AUDIO - HSP #190 - Rodrigo Cunha

Watch Video here:

VIDEO - HSP #190 - Rodrigo Cunha

Rodrigo Cunha discusses:

•The Importance of Dentin Preservation - An Evidence Based Approach

•Using technology in order to preserve tooth structure during Endodontic treatment

•TRUShape files and Dentin Preservation



Rodrigo Sanches Cunha DDS MSc PhD FRCD(C)

Associate Professor and Division Head of Endodontics, at the College of Dentistry, Faculty of Health Sciences - University of Manitoba, Canada. 

Department Head, Restorative Dentistry

Guest speaker at many events in Brazil, Argentina, Canada, UAE and USA. 

Published a multitude of papers and abstracts in several peer reviewed journals

Participated as the author and co-author of several Book Chapters in Endodontics Textbooks.

Member of the Scientific Board for both the IEJ and JOE.

Private practice limited to Endodontics since 1995

Member of the American Association of Endodontics (AAE)

Member of the Canadian Academy of Endodontics (CAE)

Member of the International Association of Dental Traumatology

Howard: It is a huge honor today to be interviewing a very distinguished endodontist, Rodrigo Cunha. How are you doing today?

Rodrigo: I'm doing great. Thank you for having me and giving me this opportunity to discuss with you guys. 

Howard: The owners all mine, you're actually very good friends with a gentleman we podcasted earlier, Ken Serota, who's also a Canadian, you're a Canadian in Manitoba. Ken Serota, I just love that guy. He can quote endodonic literature like some preacher quoting the Bible, or the Torah, or the Quran. He's just an amazing wealth of information, and he has told me so many great things about you, and how smart you are. My first question before we get into root canals, is my God you were born in paradise. You were born in Brazil, and now you moved up to antarctic in Canada. How does one go from Brazil to Canada?

Rodrigo: We like to say that we come for the weather. 

Howard: You did not come for the weather.

Rodrigo: I graduated in Sao Paulo in 1994 where I did my specialty program. I started teaching there in 1996. After 17 years of private practice I decided to move to the North Pole in order to engage in an academic career here as well. I applied for a position in Winnipeg, Manitoba, and funny thing is i didn't even know what Winnipeg, Manitoba was, but I had been in Vancouver in 2007. I remembered that when I applied for the position, my wife asked me, "Listen what's Winnipeg, Manitoba?" I said, "Don't worry I've been in Vancouver. It shouldn't be that different."

It's quite different. It is cold, it is super cold, but it's been an amazing adventure, if you want to put it that way. I've been having the opportunity to meet amazing guys, amazing endodontists, learn with them, and I know for sure Ken Serota is one of them. His passion for endontics is just...

Howard: Unmatched.

Rodrigo: Yeah, he actually, we discussed a couple of times about endo and he was the one that said, "listen you should do this and share your knowledge in whatever you've been doing clinically," and that's what I'm here for.

Howard: You wife, how long have you lived there in Manitoba with your wife?

Rodrigo: We been here, this is our fifth year.

Howard: She stayed with you the whole time, she didn't leave you and go back to Brazil?

Rodrigo: It's good, because it's so cold she doesn't leave the house. 

Howard: She can't go home because she can't leave the house. Basically, when I got out of school it was all hand instruments. I have to tell you the truth, the first five years I practiced I always had a blister on my thumb and my finger from doing this filing motion with files. In my practice, I'm in Phoenix, Arizona, I'm not in a rich suburb or anything. I did a molar or two every single day. Now, then it just slowly but surely it just turned to all NiTi rotary instrument, and I got to tell you before you get into this, I know you like a file from a TRUShape , which is Tulsa Dental Products. 

I'm going to tell these young kids, Tulsa Dental Products, the name Tulsa comes from Tulsa, Oklahoma, because that's where the founder Ben Johnson started the company. I got to tell you my Ben Johnson story. In fact, do you still talk to him? 

Rodrigo: I know of him, we've met, but we never had a huge conversation, but I know him, yes.

Howard: Anyway, he started this company, Tulsa Dental Products in Tulsa, Oklahoma, and I was a kid. I was 24-years-old, it was 1987, and I didn't understand some of the stuff. I called the operator, they used to have operators back then, and got his number. Called his endodontic practice, and I'm talking to him, and he says to me, "Well I wish I could show you, but you're in Phoenix." He goes, "You know Southwest airways they fly straight from Phoenix, so you ought to come down here and swim today." I said, "I don't think I could learn in a day, it'd probably take two days, and I'd buy the plane ticket, but I don't have the money for a hotel." He goes, "Well then stay at my house." The guy was just a saint. 

Here's this 24-year-old idiot kid getting on an airplane, flying to Tulsa. He picks me up in his car, and he's showing me how he rolled the gutta-percha, and how he made the original. Just a saint of a man. I think he's got to be the coolest endodontist in the world. That was so long ago, I don't even think he was an endodontist, back then you could just say I'm only doing endo so I was practice-limited endo. 

Rodrigo: Practice limited to endo.

Howard: He didn't even, I don't think he went to endodontic school, I believe that's what he said. I know a bunch of other guys in small towns where there will be five guys in a town, and nobody likes to do endo, and one of the guys loves it, but they're not going to refer him to endo cause he'll do all the other work. One of the five guys in the small will just say, "You know what, I'll tell you what. I'll have practice-limited endo. I'll only do the endo, I'll get rid of my hygienist, I won't do crowns, fillings, whatever." There's a lot of people practice limited to endo that never went to endo school. Anyway, enough of that. 

What would you, you've got about 7,000 dentists listening to you right now. Probably almost all of them are general dentists. I don't think I have a big specialty falling. What would you like to share in this hour? What do you think would make these people listening to you today do better endo? 

Rodrigo: Well, Howard, that's a great point. This is what happens, today we hear a lot the sentence, endodontics is a dying professional. Why are you still doing endo? Today we have the implants, why are you wasting your time trying to save something that's not going to last? I think I went from a really huge frustration to starting to try to understand why they are saying this. Trying to be realistic in seeing that yes, a lot of the teeth that we are doing are failing. The other thing I try to do is understand why it's failing. Just to get started, I just want to let you know that I think that we can do a better job, and that's what we're going to talk about.

I also want to let you know that in the University setting, and in my private practice I see a lot of implants failing. The question is are implants really predictable as they sell them, no they are not. They also fail. We have to acknowledge that's implants fail, and we have literature. We have plenty of pieces of literature out there showing that the success rate of implants is not as high as what's being quoted there. Actually, we have a huge network group that published a paper in the Journal of American Dental Association in July 2014, where they stated that success rate of implants in a general practice setting is not as high as in the University setting, or a specialists setting, as quoted out there.

The question that comes is, okay, what should we do? What should we do to increase the success rate in endo, or to decrease the failure? I think the first thing we have to do is to try to understand why root canal treatment fails. If we go back and we look at the causes; the main causes are one, missing canals. Missing canals is a huge cause for endodontic failure. What have we as endodontists been doing in order to avoid this? Today we have Dental Operating Microscope, today we have Cone-beam Computer Tomography, we have our Surgical Loops. We have enough tools to avoid missing canals.

What is the other cause? Well, persistent new infections, yes, that's also cause for failures. What have we been doing? We have new Eurigans out there, we have new technologies, we have different Irrigation Protocol, we have Sonic Activation - Ultra-sonic Activation, all in order to try to fight those bacteria and other bugs in order to give us a higher success rate. The other huge cause of Endodontic Failure is radical root fracture and I asked you earlier, what have we been doing as clinicians in order to avoid Vertical root fracture? If we really put our minds set just to thing a little bit, you're going to see that we haven't been doing a lot.

The way Endo has been taught for the last 30 years and the way they've been teaching how to do Root Canals, it's all about remove what you have in front of you, I want to reach the epics no matter what. I want that straight line access. Again, going back to the literature and I can quote Gualla De Vallah's group in 2010 that published a paper in the International Endodontics journal, they quoted that preserving tooth structure is extremely important. Excessive Root Canal preparation is one of the causes of Vertical Root fracture so I have no doubt that going small today is the way to go.

I don't know if I agree 100% with the terminology "minemiline versa endodontics" but I like the terminology; "Dentine Preservation". It's not only about doing the root canal, it's about doing your root canal and being sure that you leave enough cherum structure behind so that someone can restore that tooth and we can give that tooth the longevity that we want. Somewhat, there are two important aspects here; we, as Endodontics, we like to look a lot at the outcome. Outcome is the success of my root canal, so was my Root Canal successful, yes it was, did the lesion heal, yes it did, that's great. Okay, how long is the tooth going to stay in the mouth.

How long is that tooth going to stay stable in the mouth, the patient is going to stay --- the patient can chew, the patient can carry on with his life and the tooth is going to stay there. Howard, I think we're at the point where we shouldn't only be looking at the outcome, we also should be looking at longevity. We should at how much time I can give this tooth in the mouth and I'm always looking at the maximum possible, I want to keep the tooth there for ever. Keeping tooth structure behind, leaving tooth structure behind is paramount, for sure.

We already have studies coming from --- And I can quote Freedman's group from Toronto where they actually just published a paper in the Jelaree in 2014, comparing Conservative Endodontic access and Traditional Endodontic access. Maybe we're removing too much, maybe that strained line access that we've always been brought in teaching, doesn't have to be that straight anymore, because, Howard, if you'd think with me, Straight Line access --- the idea of Straight Line access was created when our files were stainless steel files. Old files were so stiff that we could not actually negotiate a caricature. However, 30 years later or 40 years later, we have completely new tools.

Our instruments are made of Nickel Titania, are extremely flexible and we're still advocating a straight line access. We're using an old concept however our tools are completely different. We can actually do the same removing less tooth structure, leaving more dentine behind in order to give that tooth longevity. Where does the TRUshape concept come in? When I saw the TRUshape concept, I really saw something different. You know the same as I do, we have more than 60 NiTi system rotary reciprocating systems in the market. There's too many and each one of them promising something different but when we look at them Howard, they're pretty the same.

We're always switching files but you know what? You're switching something for something that is very similar. When I looked at the design of the TRUshape purse and I went to a meeting in San Francisco where Dr.[inaudible 00:13:13] Peters where he actually introduced those files and showed how to use and the cons at the idea, all the idea of dentine preservation, "don't remove too much, let's try to keep it there in order to have something to restore late. I really said, Wow, this is genius and I think that now I've found something different. I started using, actually now, October I think it has been nine years since I've been using this file system

I like the design, it's an S-shaped file. That S-shaped file is interesting because even though the file has a specific diameter, because of that S-shape, you can still tough the Canal walls. Even though the file might be a little bit small, because of it's shape, you're still touching the canal walls even when the canal gets larger so we're still waiting for more literature but we've been seeing out there is that you can actually have a conservative preparation but still touch the canal walls in away where you can leave less bacteria behind. This system basically, consist of four different files; we have the 20-06, 25-06, 30-06 and 40-06 and they have a variable tape.

The nice thing is, it doesn't matter which one you use, if it is from the 20 all the way to the 40, all the way at the end of the file at the 16, 17 your preparation is conservative. You're preparing in a way that you're preserving tooth structure at the core of an abortion. If you need to modify the artifice, they have this instrument, it's created with the blue technology, it is a vortex blue technology where it's called artifice modifier, so you can modify the artifice and look how interesting it is. It's not about opening the artifice, artifice shapper, artifice open and now it's artifice modifier, we don't want to remove too much, we want to just modify so my file can go in easier. What else can I add to this file?

Howard: Well, you know, it's amazing. Back in the day, Dennis would start with a big, old football gates glidden and just blow out those offices and then when NiTis came out they had planned O2 Taper, .04, .06 and this tape was so huge, it was like say the main goes Straight Line access straight to the bottom and they've just blown out this whole thing and that's why you're saying that you've removed so much Dentine Structure that that's saddening this up for root fractures?

Rodrigo: I agree with you. Howard just need to have an idea, we're not even using Kate's Glidden that more, the way we used to before. As you know I am full time [inaudible 00:16:17] at University of Manitoba, neither to my students in undergrad I try to teach them how dangerous Kate's Glidden is. [inaudible 00:16:26] has a nice Research Study published in the Journal of American Dental Associate where he has showed the remaining dentine thickness that you leave behind after using Kate's Glidden, can really put in jeopardy, the longevity of that tooth. For those that find it hard to just quit the Kate's Glidden one step and you know what? I still use them, I don't know, I'm so used to them.

What I usually advice them to do is use you Kate's Glidden number 2-3, not more than that, I think we don't have to go better than a number three but use it near your electric mortar. Set the speed to 900 800 RPMs and just brush against the same wall. The wall that has the same name as the canal you're working on, that would be the safety zone, the zone away from the vacation and you're going to be doing

Howard: Well, you know, while you're talking about all these dental removal, there's a lot of controversy on how many poster play. So many of these roots are ringed out for a post and if you have a two millimeter referral all around the tooth, when do you think you need to remove a lot of dentine for a post?

Rodrigo: That's a great question and I think this won't be another one hour interview Howard, but[crosstalk 00:17:54]

Howard: We'll do it, we'll do it... If you want to come back

Rodrigo: The question is, sometimes I think we're putting too much posts.

Howard: Absolutely...

Rodrigo: Sometimes --- If I have any referral, why am I placing posts anyway? Molars, where I have 3-4 mls of pherral where I have enough tooth structure, why am I putting a post, I could just build the core. Second, being the doctors, when we're doing our obliteration and you're doing your 5 ml. fillers, 6 mlm fill, as soon as you go down there, anyone that's going to put a bolt should use that room, that space that I have inside the canal to place my bolts if I have to put a gate screening there too large, I'm removing too much tooth structure so it's the anatomy that drives my clinic not the clinic that drives the anatomy. 

The anatomy tells me what to do and I'm not only going to modify the anatomy the way that I can fit up polls there and that Okay, your polls went down there but you're just reduced the longevity of this tooth. I agree with you, I think the end a doctor should do is 5ml fill and whatever you have there as space is what you should work with. I don't think we should be using Gate's Glidden to remove more just so --- And it doesn't make sense. You're removing something in order to restore something, it should be the opposite. You should work with what you have and if you have enough Pherral I don't even see a reason why we should be placing posts

Howard: There is another --- There is another mindset that every tooth with a root canal needs a crown and I get it with [inaudible 00:19:38] that they had a big three service, big amalgamate and these entered when they have this constricted cervical marks, by the time you prepare this tooth for a crown, you're looking at a grain of rise, it's ridiculous. They file these teeth down to nothing to restore with a crown.

Rodrigo: I agree with you a 100% Howard. Sometimes I see them removing to build there. Why are you removing, use what you have there already. Yes, for posterior teeth full gaspal coverage is important to avoid fracture and I agree but interior teeth, no, we could be doing more removing less. We could be putting those --- Today we're having all ceramic crowns, we have beautiful materials coming down, we don't even need the posts. If we have enough tooth structure, build the core and put the crown, for sure.

Howard: On these NiTi files, they had a .02 taper, .04, .06, where do you draw the line, what's too much taper

Rodrigo: That's a great question again. The anatomy is going to drive my preparation. I don't have anything fixed, if I have a tooth, a large tooth that allows me to go up to a .6, I will. If the tooth is constricted to start with and I have to start with an old four, I don't mind it at all. Staying between .4 and .6, that's where I want to draw my line. I don't want to go less than .4 and I'll try not to go more than .6. If you look at the new systems that are coming to the market a lot of them are already reducing their tape. They're coming with a second version of that file, however, there are some different features in that file and one of them is "okay, we have knowledge that we have to preserve, let's reduce the tape".

That's becoming a trend, trying to do root canals, preserving more tooth structures. I know [inaudible 00:21:43] what I usually like to finish but I know six depending on how big the canal is, I think it's still fine.

Howard: You're very sold on total dental products and Ben Johnson's company's new TRUshaper file.

Rodrigo: I like those files a lot. Basically, I do my root canals with those TRUshape files. There are cases where I also like to use the wave one and you know what Howard, it's not about the system it's about you, if you know your protocol, you're done and I always, when I present lectures to General Dentists, the message that I like to tell them is the difference between and Endodontist and General Dentist is how much time we spend with a number 10 in 15 hand file. We spend a lot of time with the 10 in 15. I don't try to do anything if my 15 end file is not loose in the canal. Those glide path files that they have today is amazing, I think that's the top secret.

If you can get one of those file systems all the way there and you have a nice reproducible glide path, give any system, you can work. The beauty of the TRUshape that I like is that you can do the same as other systems preserving more tooth structures, that's the beauty of the TRUshape that I think. I like to preserve tooth structure and that system really allows me to do that.

Howard: My job is to try to gestate the questions that 7,000 individual people are thinking of regarding the work and you just said the glide path was so important and that the difference that the Endodontists and the General Dentists was how much time they have with the 10 in 15 file, you're talking about a hand file?

Rodrigo: Hand file, hand file...

Howard: Okay, were you talking about --- what is the first file you drop at the tooth and talk about how you establish your glide path. What are you thinking when you're in a mole, trying to establish a glide path before you go pick up a 300 RPM NiTi?

Rodrigo: I'm going to tell you my --- what I like to use as a protocol is, I don't put any kind of rotary, doesn't matter if it's a shappy rotary or a glide path rotary inside the canal, if I don't have a number 10 hand file loose inside the canal. My root canal treatment does not start until my number 10 file is actually going in and out 3mls of amplitude, loose inside the canal, then I'm okay. Usually, with a lot of lubrication, I like to leave my canals flooded with much sodium hydro-chloride, I just [inaudible 00:24:18] I try to go as close to my range of graphic length as I can.

I do this in one, two or three steps, I don't try to do this at once and I'm trying to do --- We always say that the eyes of the Endodontics are on the tip of their fingers so that's what we're trying to do, we're scanning the  canal, we're trying to get as much in formation as we can from the anatomy. Is it constricted, can I feel that it gets constricted this area. My file is pre-curve, do I have a catch in the middle portion, maybe my canal splits over there. The more information I can get at this point is really going to facilitate my shaping procedure.

As soon as my file is really close to my retro-graphic length, I'm going to irrigate a lot and I'm going to try to determine my working line. As soon as I determine my working like, I have a predictable glide path. Now, another interesting thing to give as a clinical tip is, I always keep a number 10 hand file one millimeter further than my working length because every time I'm working, I always re-capitulate with that file and I'm sure that I'm going beyond my frame in a millimeter in order to leave my frame and unblot. That patency file is a file that I use every time I get off with this different pack I go back with that one to be sure that my frame is in same block. 

When my 10 file is completely loose inside the canal, I try to take my 15. This is to create a manual glide path so I'm going to do the same thing and I'm going to try to get my 15 all the way to my working length and be sure that my 15 hand file is loose. When my 15 hand file is loose I have a nice, predictable glide path with a 15 hand file, I'm good to start my rotary shaping procedure. If I want to use a rotary system, we have several in the market, actually Tulsa has one that I really like, called Prog-lighter where you can actually get your glide path with only one NiTi instrument.

As soon as my prog-lighter gets down there, the tip of the prog-lighter is equivalent to a number 16 hand file, I have my glide path so I don't know if I made myself understood but I do not start any rotary treatment procedure or shaping if I don't have my 15 hand file loose or my prog-lighter all the way down there. If you like to use the path file's three different files, you want to take at least the path file number two all the way down there so you have a nice glide path over number 15-16, that's what you want. I spend a lot of time in this procedure, Howard. I spend a lot of time and I irrigate a lot so if that's completely loose, my file is loose and my canal has been previously irrigated [inaudible 00:27:18], I'm ready to start my shaping procedure.

Howard: How long would you say the average Endodontic spends on a molar, just so, these General Dentists can put in perspective?

Rodrigo: Depends on the case, depends on the number of fillers. You look at an average, I don't do a molar for less than five to six units, that would be around 1 hr. 15 mins. - 1 hr. 30 mins because, you know what, Howard, our shaping procedures today are actually allowing us to shape faster. We can achieve a complete shape of a canal super fast. However, we must understand that we need to leave our irrigant   inside the canal. Our irrigant has to do it's job. In order for my irrigation to be effective, time that my irrigant stays in contact with the canal walls and with the bacteria is also paramount so again if you go back to the literature, you're going to see that you want to irrigate high volumes for a long period of time in order to have an effective irrigant and an effective irrigation protocol.

Howard: So, the longer that irrigant is in there, the more you add [inaudible 00:28:29] and do you think if helps to agitate that, so you might require a sonic or ultra-sonic?

Rodrigo: Both. It doesn't matter, both Sonic and Ultra-sonic are effective. I like the sonic just because the tip is a plastic tip and if the canal is curve I can still go there with the sonic because the tip is still it's tip. It is an anti[inaudible 00:28:53] on your stainless steel tip, you might not be able to do the curvature and I don't want a large or remove two structures so that's why I like to use a plastic tip. You said something there that's super-interesting, yes, you must agitate the sodium hydro-chloride as well, it's not only the EDTA at the end, I agitate every two irrigation so every time I irrigate twice, second one, I'm activating for 30 seconds, at least.

Howard: When you're irrigating how far down the canal are you getting your needle to?

Rodrigo: That's a great question. We like to go down with a 30 gauge needle and I try to go close to two millimeters short of my working length, that's where I want to go. Don't put too much pressure. Don't put pressure on the plunger, we want to keep that needle free inside the canal. We want to go in and out, in and out, we do not want that needle to burn inside the canal in order to avoid any accident with sodium hydro-chloride. Yes, there are other systems in the market that allows you to do a passive irrigation. We have the endo-vactrone example. I like just to use my needle, again in and out, I always, always put a rubber stop on my needle. When I put the rubber stop on my needle, I'm sure that I'm not going beyond the limit that I want and I'm keeping my needle two millimeters short of my working length.

Howard: What brand of sonic are you using? What brand, how can someone buy one?

Rodrigo: The Sonic I use is the Endo-activator from Tulsa.[crosstalk 00:30:32]

Howard: Endo-activator?

Rodrigo: Yeah.

Howard: Okay, I want to switch gears to a lot of Dentist wonder if they should do this molar in one appointment or they should medicate and come back. What are you thinking about, when you decide, you know what? I'm not going to ob-filtrate this today, I'm going to --- why would you do that and what medication would you put inside the tooth and how long would you have them wait?

Rodrigo: Okay, that's good. With regard to doing root canal treatment in one visit or two visits, we have enough scientific evidence that that doesn't influence the outcome so what really drives me towards doing one visit or multiple visits, what really differs is, "can I dry the canal", first question, "can I keep those canals dry?" "Do I have exited puss, blood coming?" If I have any of these situations or scenarios, I will not offer treatment the same visit. Another scenario that would not allow me to do in one visit is emergencies. If the patient comes to our office with an acute [inaudible 00:31:39], I'm just going to remove him from --- give him some relief and then I'll work in the next visit.

Another aspect that would also drive me towards a multiple visit Endo is difficult anatomy. Sometimes we have difficulty dealing with the anatomy and we actually get tired. There comes a point where your hands are tired, you just can't work the same way. I stop and I work at the patient another visit. So those scenarios are what would keep me towards doing an endo in two visits. What do I use? I use calcium hydroxide as my intra-canal medicament and I think that even though nowadays we know that it has a limited anti-microbial effect, it has some but not as much as we would like that it would have, it is a really good barrier against leakage. 

I put calcium hydroxide and if it's for an anti-microbial I try to leave at least two weeks, otherwise, I just leave it there until my next appointment as a barrier.

Howard: Would you call yourself and epical barbarian or a pop-lover, meaning the epical barbarians they love to get the final though I can see a path sealer at the end and you said you're going a millimeter long [inaudible 00:33:03] or you're pop-lover and you like to just stop a millimeter from the true epics.

Rodrigo: I do not want the puff [crosstalk 00:33:16] ---

Howard: You don't want the puff.

Rodrigo: It's not something that I do intentionally but I get the puff in 90% of my cases.

Howard: So then, you're an epical barbarian.

Rodrigo: The question I'm going to ask you is, we know that there are some --- There are like phylosophies that actually are against that path, however, we all get exited and we're happy when we obtrate a leteral canal. I've never seen a lateral canal being obrated without a little puff in the lateral portion. We celebrate but if I get a puff in the epical portion I'm going to get sad. It's the same tissue if the perio-dontium it's just a lateral perio-dontium and the epical perio-dontium, what is the difference. If I allow myself to obtrate and I want that, a leteral canal knowing that in 99% of the cases, I'm going to have a puff there and I'm going to celebrate, what is the problem I have in an epical puff if the tissue is the same? It's not going to influence my outcome at all.

Howard: When we were talking about failed root canals, you were talking about miss-canals, you're talking about that would be correct with the CVCT. When a failed root canal comes into your office and you're wondering why it failed, are you finding these vertical root fractures with the CVCT or not really?

Rodrigo: Not really. Let me answer you that question in two different topics; first, I do a CVCT scan for all my cases when I'm re-treating. When I'm re-treating I do a CVCT scan for all my cases and the amount of miss-canals that we see in the CVCT scan is just huge.

Howard: Where are these miss-canals, are they more specifically in a few teeth or they're in every tooth in the head?

Rodrigo: I'll tell you, lower pre-molars, Medieval pre-molars, we see a lot of miss-canals, sometimes it splits in the middle of the root and you've missed that lingual root or that lingual canal. MB twos, MB twos in second maxillary molars. We know that they're there and we see them being missed a lot. Lower molars, we see sometimes there's tobacco canal miss so lower incisors sometimes we see a lingual canal miss. Those are basically, what we see. I like to do a CT scan and always a limited field of your CT scan in order to address that and that really guides my access. It guides my access to be conservative.

You know him and I know that he's giving a C-course for you, William [inaudible 00:36:07] has an amazing paper published and he gives also a talk on selective re-treatment. CT scan allows me to do that, it gives me the exact spot where it was missed, where the lesion is and sometimes it can be more conservative on my re-treatment just addressing the root where the canal was missed so again, I am preserving tooth structure when I'm doing that. When it comes to vertical root structure ...

Howard: Because in that case you wouldn't go back and re-treat the obstrated canal, you will [crosstalk 00:36:39] just go back and re-treat the missed canal.

Rodrigo: Especially when using a CBCT Scan, you can actually precisely determine if there's lesion in the other canals. If there's not, I'm going to discuss with the patient and I'm going to address only where the issue is as long as the other canals radio-graphically seems that everything is Okay. With regard to the vertical root fracture, now this is controversial, I don't --- There's so much artifacts that we can't determine precisely, Okay, there's a vertical root fracture here. I'd rather go more with signs and symptoms of Deep Narrow Package, J-shape lesion, Sinus track close to the Ginger hole margin. That gives me more information than the CT scan when it comes to the vertical root fracture.

I know that some really rely on the CVCT scan for vertical root fracture, I just think that due to the amount of artifact, I always have that little question mark, is this really a fracture or an artifact so I rely more on clinical signs and symptoms.

Howard: What do you like more to distablish you working list, do you like CVCT, Epex Locator, Digital radiography, putting a paper point there and seeing a --- goes out the Epex and the red bleeding stuff the white starts, what do you like to do for distablishing?

Rodrigo: Actually, I do a combination, I like to use my Epex locator, my electronic Epex locator.

Howard: What do you use?

Rodrigo: I use root [crosstalk 00:38:18] Yes, the Root CX that's the one I use. I like to do a radiograph. After I use my Epex Locator, I take a picture, I do a [inaudible 00:38:31] and I take a peri-epical radiograph because the Root CX is going to show me where my length is but when I take my radiograph it shows me the anatomy. Now, I have my file there and sometimes I see a little hook or a curvature that I could not see in the radiograph. Knowing the length is important but also looking at your file inside the canal and looking the shape that your file has inside the canal, gives you a lot of information with regard to the anatomy.

My next step is I use my paper point at the end. My paper points are going to be my last guide in order to determine which is my working line. I also use my Root CX attached to my rotary files when I'm using my rotary just to be sure that I'm in the right length as well.

Howard: Back to one step or two, your whole thinking and whether you're going to one appointment or two appointments really, can you get the --- do you have the time and can you get all cleaned out and can you get it dry?

Rodrigo: Yes.

Howard: Okay, well, some people say that if there's a peri-epical radio-lucency that an intra-canal medication would be better. Do you agree with that or disagree with that? Does a peri-epical radio-lucency change your mind on that?

Rodrigo: No, it doesn't.

Howard: It does not.

Rodrigo: No. It's more about --- again [crosstalk 00:39:59]

Howard: Did they used to teach that 10 years ago?

Rodrigo: Oh yes,[crosstalk 00:40:03] to hell if you obtrate in one visit if there was a lesion ... [crosstalk 00:40:09] But again ...

Howard: So, I just solved one of my own bias, I'm educating myself there because I was always told [inaudible 00:40:17] came out to me with a ruler and starts spanking my hand with a yard stick if I once skipped with the peri-epical radiolusive  but you say that's old-school, that you don't see ...

Rodrigo: Well, I'm not going to say it's old-school, it's a different philosophy, I respect that. If someone comes to and said, you know what? If there's a [inaudible 00:40:33] I never do it in one visit, I respect and I think he's doing a hunk of a job, beautiful. But if someone comes to me and said, you know what? Lesion doesn't make any difference as long as I can clean everything I have a epical[inaudible 00:40:46], I have my patency and I can still dry the canal, I think he's doing a great job as well. I don't think --- And again, we have enough literature today to support that there's no difference between single and multiple visit with regard to the outcome of endodotic treatment.

Howard: Okay, do you ever use antibiotics when you're doing root canal?

Rodrigo: No, I don't for me. The specific reason I don't use that is that, it's a poly-microbial infection and when I use antibiotics ...

Howard: Explain what you mean by poly-microbial.

Rodrigo: We don't have only one species of bacteria inside the canal, we have so many bacteria inside the canal microorganisms that my antibiotics might work against one species but might not work against the other and I'm just causing more resistance and I don't want that so I think I'd rather use an anti-microbial agent like sodium chloride or even sometimes adding chlorexidine but I would not use an antibiotic, for sure.

Howard: Do you believe or do you feel that General Dhanesh over prescribed antibiotics during canal treatment?

Rodrigo: Yes, I do.

Howard: I know General Dhanesh said every single patient for 20 years, gets a prescription [crosstalk 00:42:05] for NVK or amoxicylline with every root canal.

Rodrigo: I do too, and that's sad because I rarely prescribe antibiotics. If you understand that the cause of infection or the nature of the infection is inside the root, your antibiotics is not going to reach that area at all. You're giving antibiotics for nothing. You might as well, go inside, decrease the bacteria load and you're giving condition for your body to heal. Antibiotics should only be used if there's any signs or symptoms of the dissemination of the infection. Fever, malaise, lymphadonopathy, cellulitis, I would agree, otherwise I do not prescribe antibiotics and antibiotics is only adject. What you do inside the canal is what really makes a difference.

I always like to tell my students that the best antibiotics we have now Howard, is called bleidillen, so you just get your [inaudible 00:43:06] you just drain that. Allow drainage and you're going to see how the patient is going to feel much better in 24 hours. You might use antibiotics if you think that the infection has spread, that's fine. Otherwise, draining is sufficient to cause relief to the patient.

Howard: What about pain medication afterwards, do you regularly always prescribe pain medication after a root canal?

Rodrigo: I'm not going to tell you that I prescribe always but let's say that I really advocate my patients to take if they're here if they can, to take anti-inflammatory drugs for the first 12 hours. If they could take a couple of hydroprophane after the procedure and eight hours later, another couple of hydroprophane, I think that's more than enough because that's when we have the peak of the inflammatory process 12 hours after.

Howard: Again, I know Dentist, a 100% of the root canals, they would give a prescription for an antibiotic like [inaudible 00:44:16] and [inaudible 00:44:17][inaudible 00:44:20] do you see that too?

Rodrigo: No, I see that, but I don't agree. We don't need to go that far. Sometimes just regular tylon is more than enough for the first 12 - 24 hours and antibiotics only if needed I won't prescribe for all the cases ... I see dentists prescribe antibiotics for viral pop. The pop is viral, inflamed but viral, why am I giving antibiotics if the nature of the pain is is inflammatory, why am I giving antibiotics for that.

Howard: What do you think is a better post-offer for that [inaudible 00:44:55][inaudible 00:44:56] or the [inaudible 00:44:57] anti-inflammatory?

Rodrigo: I like the Motrin or the Hydroprophane, yeah, that's what I like but if the patient can't take anti-inflammatory drugs or they're allergic to it or asprin, I will just use [inaudible 00:45:10].

Howard: If you did a 100 molars, on what percent of them would you use Sodium Hydro-chloride, EDTA, Chlorexine or let's talks irrigants for a while. Do you sometimes do you always use, Sodium Hydro-chloride, EDTA and Chlorexine [inaudible 00:45:29] what are your thoughts on irrigants ... And did I mention irrigants that you use that I did mentioned?

Rodrigo: No, Sodium Hydro-chloride I use in all the cases, that's my main irrigant, Sodium hydro-chloride, that's my main irrigant full strength, that's what I use. Between 5.256%, that's the concentration of the Sodium hydro-chloride that I use. Activate my sodium hydro-chloride during my whole procedure. When I'm finishing I only use EDTA and you know I like to have my EDTA inside the canals, canal's completely flooded while I'm doing my GP fit so while I'm doing my GP fit my canal is flooded with EDTA and it does its job while I'm doing my GP fit.

Now, here comes a difference, I try to separate vital pop from infected, nicrotic with or without lesion. If it's a vital pop I will use Sodium Hydro-chloride during 90% of the procedure, EDTA as soon as I do my GP fit, my final irrigation with sodium hydro-chloride, dry the canal, I'm good to go. If I'm working and Nicrotic case, with or without lesion, after I use my EDTA and I'm sure that I irrigated a lot with EDTA to remove my sodium hydro-chloride, I'll do my final rinse with Chlorexidine just to enhance my antimicrobial action and I like chlorexidine due to it's substantivity, it's residual effect so I binds to the dentine and I like that residual effect so that's how I separate my protocols.

Howard: I know Dennis personally she's a great friend of mine. She's always uses also hydrogen peroxide she says, for the [inaudible 00:47:22] bacteria. What would you say to her?

Rodrigo: I would say, "use Sodium Hydro-chloride as well", that's the same thing. I don't think that she's doing a bad job using --- No, it looks great, I think she's doing amazing job. I just want to keep it simple, otherwise we go back to that area where we had 300,000 irrigants and we would spend more time thinking what are we going to put inside, no, no. Make it simple, make it easy. Sodium Hydro-chloride, EDTA or sodium hydro-chloride and chlorexidine.

Howard: Again, my job is to guess questions that someone out there and these are podcasts huge fans and of course and someone might not know what EDTA is.

Rodrigo: Okay, EDTA is a keyloid  so it's going to bind to the calcium and it's great to remove smear layer so at the end of my cleaning and shaping procedure, we produce a lot of smear layer, those dentine mud that stays attached to the walls and we want to remove that so when we use EDTA I am actually removing that smear layer and I'm leaving my dentinal tubal spartan so the canals --- I'm going to have a better --- my obliteration, my filling is going to be well adopted when I remove that smear layer. That's the only reason why I use EDTA, it has no antimicrobial effect. It's only reason --- the only reason why we use EDTA is to remove the smear layer produced during the shaping procedure.

Howard: I want to switch gears and talk about something that's kind of, controversial, politically incorrect and we shouldn't talk about but the reality is this, I see the law suits that are settled and some of these are Dental malpractice companies send me reviews of what the claims are made. They're still paying claims for the use of [inaudible 00:49:16] [inaudible 00:49:17] into and when I talk to some of these Dentists they still say thing that, well, I want an active ingredient and my sealer and if I use surgerny with [inaudible 00:49:30] it's going to keep killing bugs and I've used that stuff for 40 years and at least Endodontic or two anal, they don't get it. What do you say to those guys?

Rodrigo: Well, I would say two thing; One, the time to kill the bugs is during cleaning and shaping so when you're ready to obliterate, you have to be sure that you killed as much as you can. Second, for those that have been using surgentry base for 40 years, do you think they would have a different result if they did not use surgenty paste? That's the question so the success rate they're having is not due to the surgenty paste it's due to the good job they're doing with the cleaning and shaping, surgenty paste. We don't have one relevant piece of literature that shows us surgenty paste has any effect in mixed with the sealer so I don't think there's any reason for us to use it and the time to kill the bugs is during the cleaning and shaping, stay a long time there. Howard, trust me, I use between 10-12 syringes or 10mls during my clean and shape procedure.

How many General Dentists use 10-12 syringes during their cleaning and shaping procedures, not as much. I know general dentists that use just one or two syringes during their whole root canal treatment in a molar. That is not enough, so change your protocol, change your disinfection protocol and you won't have to rely on any antimicrobial [inaudible 00:51:06] sealer. Your filling is there for one reason; to perpetuate the environment that you achieve during your disinfection.

Howard: You're very --- gosh, I love this. You're just a fantastic communicator, fantastic teacher. You're amazing. I want to switch gears and go to Microscopes. When I got out of school in '87 they weighed a million pounds and they cost a million dollars and they keep getting lighter and smaller and lower cost. When should someone consider getting a microscope and what brand would you get, how much do you think they cost and what parse, if you did a 100 molars, if you Rodrigo did a 100 molars, what [inaudible 00:51:50] and time would you pour it out and use it or do you have it mounted on your sealing there all the time?

Rodrigo: Well, I started using dental operating microscope in 2000. When I bought the dental operating microscope Howard, I thought it was the most expensive coat hanger I ever bought in my life because the learning curves through it is gianormous, it's too much. For you to start learning the microscope, you really have to be engaged and understand that there is a para-dime shift. In my opinion, you should buy a microscope as soon as you leave Dental School. Today, you ask me how many cases I use, today I use my microscope to do my health questioner just to have an idea[inaudible 00:52:38] of my microscope so there's no way I can survive without it.

Howard: What is the brand and how many axis are you using, 8, 10, 12?

Rodrigo: I use between five to eight ...

Howard: Five to eight.

Rodrigo: Five to eight.

Howard: And what brand?

Rodrigo: There are two main brands here in Canada; Xeis and Global, I know there are others. Xeis, in my opinion is still the number one, I like the technology, I like ...

Howard: That's out of Germany, Xeis?

Rodrigo: Yes, and I like the ideas, they have amazing features through the microscope. You said something about putting on the ceiling, great idea, you can have them mounted. The other thing that I would like to tell the general Dentist is, if you left dental school now my advice is just to start working with microscope. The more you wait, the worse it's going to be because now you have your routine, you have your [inaudible 00:53:34] you have your ergonomics there, to start from scratch, it's really giving two three bucks going backwards. As soon as you left dental school, you're still learning, it's still a learning process. Starting with a Dental Operating Microscope is the best thing to do.

Howard: How much is that microscope size?

Rodrigo: Between 18-20,000 you can buy a basic model. You don't have to go to the full BMW or Mercedes, you can start with something simple and add the features as you get used to it so I don't see any reason --- let me do a quick math with you and this is what I do with my students when I'm lecturing. If you're doing Endo in your office and you have to refer one molar a month because that molar you could not do more because you were limited with regard to vision. If now you can do that molar, you're making $900 more. $900 a month, you can lease a microscope easily so it pays for itself.

It's different than the CVCT scan where you're going to have to spend $150, $100. No, this one, $20,000, if you lease it you'll pay off easily with the amount of cases that now you're going to do instead of having to refer plus you're not going to become more picky with what you're doing, you want to be more diligent to how you're doing Endo and you're going to be doing a better job. For sure, it is a game changer, you're going to be doing a completely different Endo when you work under the Dental Operating Microscope due to the magnification and the increased illumination. Both of them together allows you a great vision of where you're working in.

Howard: There I understand magnification, you said illumination from the light that you're --- the light shining down into the canal?

Rodrigo: Yeah, they have a really good light shining down. I don't even use my lights from the operator, I just use my microscope. If for some reason I want to look with my naked eye, I just put my microscope up [inaudible 00:55:50] putting it's light against the operatory field that I'm looking at.

Howard: Between that Xeis and Global, which one do you personally like more?

Rodrigo: That's a good question, if you would tell me that you were going to give one of those as a gift, I would go with Xeis for sure.

Howard: Xeis, all right and Global, where is that out of, St. Louise?

Rodrigo: I think we have Global here in Canada, I know that we have Vancouver, that's where --- in the States, I'm sorry, I don't know, I don't know where it's coming from.

Howard: Back to CVCT, some CVCTs you'd always --- other donors seem to like this brand more and the donors seem to like another brand more. Do any donors like one brand of CVCT more and start doing mostly Endo as opposed to what the donors do in ...

Rodrigo: I think there are two main brands. With Endo what's super important first for me to give as a message to whoever is hearing us is, for Endo we only need a limited field of view, so when you're asking for a CVCT image, ask for a limited field of view. You have a better resolution, less radiation for the patient and there's less tooth structure or structure for you to the interpretation, so you're responsible for what you're looking and you don't want to miss anything so. Field of view gives you a 4x4 image and we don't need anything more than that.

The two systems that I use and I work with, the one I prefer most is the J-Morider. J-Morider has a great CVCT scan machine and there's also kerostream so both of them allows you a really nice field of view, the resolution is super nice. I like both of them, I still think the image that J-Morider gives me, I like them more than what I get from Kerostream but both of them are good, you would be well served with either one.

Howard: Do you remember how much a J-Morider costs and how much are the Kerostream?

Rodrigo: I think J-Morider, with a limited field of view is close to $100,000.00, Kerostream between $80,000.00, something like that. I don't know exactly how much it is but we're pretty close to the $100,000.

Howard: And, man, that hour flew by so fast, I mean I loved listening to you, you just quote these stuff like poetry, we covered everything from A-Z, I don't know if I missed anything, I'm looking over my notes like, man, I think you hit it all, you're amazing. Hey, I want to tell you that this is a podcast have exploded because it's a multi-tasking behaviour Most Americans have an hour commute to work and these things are on their phone so they're listening as they're driving to or from work and they're just actually spoke; "but we're also online CE, we put up 350 course and they've been viewed over half a million times [crosstalk 00:59:04] I would give anything if you'd put up Endo course because when we ask them what do you want information on, the two three things that beat them up the most is Root Canals, Implants and Business Practice Manager overhead and God, I can't think of anything I love more than getting a Root Canal Course from you.

Rodrigo: Great! Just give me the date and we'll do it.

Howard: All right! And if you see Ben Johnson, the founder, you mentioned [inaudible 00:59:35] at least four or five times in this deal and he's the founder of that, Ben Johnson, have ever run into him at a Endo meeting? You tell him that Howard Ferran wants to Podcast on him. That was just an amazing journey. Thank you so much for all that you do for Dentistry and Endodontics and congratulations on your outstanding career and thank you so much for spending an hour with me today

Rodrigo: Thank Howard, it was great. Thank you for the opportunity.

Howard: All right, have a great day.

Rodrigo: Bye Bye.

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