Master Apical File and Patency Techniques

Teaser:
As long as you understand when you’re doing, you’re trying to like determine tug back and you’re trying to determine the master apical file size, for example, right? Those skills you do with hand files and they’re universal.

The most important thing is more important than the final system – Root canal without rubber dam is like doing heart surgery in the toilet. The thrill of the fill. Okay. You put your GP in and it looks as though it is to length and it doesn’t have any voids in it.

And we think, wow, this is success. Right? But the thing is, when you see a radiograph, the radiograph cannot tell you. Whether rubber dam was used, whether hypochlorite was used, whether the coronal seal was really that good, and what protocols were used in terms of this disinfection.

Jaz’s Introduction:
Basics of Endodontics. Welcome back to another Protrusive Student Series. This arm of the podcast is for students, young practitioners, those returning back to practice, or you just love listening to the podcast and you want validation. Welcome new listeners and welcome back to the returning Protruserati. We were joined with our Protrusive Student, Emma.

As she transitions into her final year of dental school, she asked all the right questions. Do you always need cuspal coverage after root canal? What kind of cuspal coverage should we go for? What determines if your root canal has actually been successful? Like we’ve all seen root canal treatments that been there for 30 years and they look questionable on the radiograph.

But there’s no pathology. Does that still count as a success? How about hand files versus rotary? Are hand files obsolete? And lastly, how significant is GP pumping to agitate your arrogance such as hypochlorite? All these questions are much more discussed in this episode.

And as of a few episodes ago, these episodes are also eligible for CPD. So if you want some easy CPD for those who are paying subscribers on the Protrusive Guidance app, don’t forget to answer the quiz. You would’ve done all the hard work of listening. You might as well get the CPD saying so by time December comes, you’re absolutely laughing. Let’s join the main interview and I’ll catch you in the outro.

Main Episode:
Emma, welcome back to the podcast, a Protrusive Student. How is your summer going? You know, I mean, I remember specifically this transition from fourth year to fifth year. And it’s really strange because like for you, it is different in a way ’cause you’ve finished your finals, right? You’ve passed.

So congratulations, congratulations once again. But it’s like you’re about to enter the final chapter. It’s a bit emotional the next round when you finish finals and then you have like, you enter the rat race. That’s an even bigger, weirder scenario. But tell us about where your headspace is at the moment.

[Emma]
I think for my final year, now that I have my exams over, I’m actually kind of excited. I think a lot of people are finding the same. I find a lot of people at Glasgow say that final year is their favorite year, because you don’t have that stress of exams. You’re more just working as a wee dentist and getting put into different outreach placements and you’re just clinical all day, every day, pretty much. So it’s just purely building on your clinical skills and getting more knowledge. So no more lectures. So I’m actually kind of excited for it. 

[Jaz]
I think that’s so cool. I’m very envious of you actually, because in most dental schools, the final year is like this crushing one. I mean, I can remember, the sheer emotions that you experienced during fourth year, but then it all culminates and I think it’s great that you managed to get out the way in fourth year, and I could really just focus. Your focus shift towards how can I get myself prepared for the real world, right? 

[Emma]
Yeah, for sure. But definitely this time last year, very nervous. But this year I’m feeling good. I’m feeling excited for it. 

[Jaz]
Good. I’m really happy, I think this is the best way because now that your focus is, how can you prepare yourself for the real world of practice? You learn differently. ‘Cause I find like with anything, most of the learning happens right towards the very end. There’s a very valuable amount of learning in any cycle that happens towards the end.

And when you have a traditional model of schooling in dental school, whereby your finals exams are in the final year, you are kind of learning to pass an exam, not learning to serve your patients better, improve your clinical skills to as much as you want to. Yes, that’s always, there is a constant theme in the background, but it’s never at the forefront. But now I think you and you guys at Glasgow get to experience this, which is wonderful.

So, amazing. And today we’re talking about Endo, right? So students’ perspective. Emma had asked me, Jaz, do you want the questions as I know, let’s go with the flow, right? Because I’m no endo specialist. I’m no endo expert. In fact, I do less endo now, like over the years I do less and less and less endo.

Actually, funny story about that, Emma. One stage I wanted to specialize and I couldn’t decide where. So when I initially entered dental school and I was like 19, I was like, I wanna do ortho, right? ‘Cause I had like braces and I had teeth align. I was like, wow, how do I bottle this up and give this to people?

So, I’m gonna do ortho. And then in dental school, ortho clinics were like the most confusing things ever. Like, what the hell’s going on? No one knew what was going on, it was madness. And I decided very quickly that, okay, ortho is probably not for me. And then my focus shifted towards endo. And I was enjoying my endo.

I won a few prizes along the way ’cause I was doing so much. I was really growing gross in Endo during dental school. And then I met a guy on the train and he saw me reading the Understanding Past Dentures book. Right? And then he sat in front of me and he noticed my textbook. And he said, yeah, you’re dental student.

I’m like, yeah, yeah, yeah. And he was talking to me. He was a dentist in the real world. Probably about 15, 20 years qualified. And he goes to me, are you sure you wanna specialize in something that’s this tall and this thin? And for some reason the bugger really, you know, that night he kept me up thinking he’s right.

Why am I specializing in something so tiny? Right? And then I decided, you know what, I’ll rule them all. ‘Cause at that stage, if you are a specialist in restorative, you can do, can be a specialist in Prostho. Perio, Endo and be all those. So I thought, okay, why not have one specialty to rule them all? And then I went to hospital training and I thought, the way I say it now is, have you seen the film Zootopia? 

[Emma]
I haven’t actually, no, I haven’t. 

[Jaz]
So good. Right. It’s such a great film, by the way. I love films like that. Anyway, in Zootopia there’s a sloth, right? You might have seen this meme or this video of this sloth just so slow. So if I was to symbolize hospital or personify hospital dentistry, it would be that sloth, right? Just so slow. And I couldn’t, my neurodivergence couldn’t keep up with that. 

So ultimately, I settled in private practice doing what I, I love what I do. Honestly, I’m a general dentist and I’ve got my niches of occlusion, TMD, restorative, and I do endo less and less, but I do enjoy every time I do it, I refer the more complex things like molar stuff, you have the Dunning Kruger effect.

You know, when I was a student, I was like, yeah, I could do molar endo. I’m willing to have a go. But with the more experience I have now, I’m noticing these gentle curves and things which you don’t notice when you’re young. And now I’m very quick to refer and get the referral pad out.

Anyway, that was a long way of saying, Endo once really interested me. Now I’m cool with it, but it’s not my area of expertise, but to a student, I know my foundations and I’d love to help clarify Endo for you and all the students listening today and to young dentists as well. 

[Emma]
Yeah, for sure. ‘Cause so it’s just some basic things and I’m at the same stage now for, like, my mom, she’s a dental nurse. She’s asking me, are you wanting to specialize X, Y, Z? And I think, well, I just have no idea. You have no idea until i’ll probably get into my VT year or my foundation year because I’m just rubbish at everything at the moment.

I’ve arbitrated about five canals at this point, so I’m just not good at anything. 

[Jaz]
That’s a minimum. You met your requirement. Wish you can graduate tomorrow and you’ve met the minimum requirement. 

[Emma]
Yeah. So I’m just rubbish at everything at the moment, everyone is. So, I have no idea of what I’m wanting to do. But I remember when I first was going to dental school, I was working in an NHS practice as a dental nurse, and I was told, with all the rotary files, but they were saying, when you go to dental school, you’re going to be using hand files, you’re gonna get taught with hand files, everything’s gonna be hand files.

And that’s how you’re taught in dental school. And then when I’ve got into dental school, I’ve never done a full canal, like with hand files and they’ve got rotary endo, which is good. But yeah. I was gonna ask what your thoughts are on rotary versus hand files, like for beginners, if that’s something that you experienced.

[Jaz]
Yeah, so we did our training on K files and incrementally bigger K files to create the right taper using the K file technique. And then we also had access to rotary as well. So I had a bit of both. And then this thing happened whereby you qualify and it was this really terrible thing, Emma, whereby if it was a public system patient, they’d get one, like a hand file system.

And then if it was a private patient, you’d get, like, you get to use the fancy ones, which are more expensive, which I get because if there’s a significant cost out later to practice for using rotary. But I didn’t wanna practice this way in terms of differentiating. I want to do the best I can, which is one of the reasons I went to private practice.

‘Cause I just want to do the way I was trained and essentially like we know that the hand file system works, it’s just not as efficient, but it’s great to be held to ’cause so much tactile feedback is involved in Endo and to have those skills, being confident with the K files and Hedstrom files and the basics of it.

As long as you understand when you’re doing, you’re trying to like determine tug back and you’re trying to determine the master apical file size, for example, right? Those skills you do with hand files and they’re universal. So I think when you’re learning whatever training comes your way is great, but know that sometimes choosing the rotary path, and if you are irresponsible with using rotary and you do what we call a strip perforation.

So for example, you’re kind of going through the route ’cause you’ve been too aggressive or you cause ledges or you cause file separation, that kinda stuff because you’ve been too aggressive, then that needs to be balanced out with being a safe beginner, but just going a bit slowly with K file.

So either is good. The most important thing is more important than the file system is the disinfection. Are you doing rubber dam isolation? Are you using hypochlorite? Which is the best arrogant that we know at this moment in time? So those are more important than the file system. And as you become more confident, then you’ll be able to be able to choose, okay, this one I’m gonna do hand file this, I’m gonna do rotary. But more often than not, you will be doing rotary in the real world. 

[Emma]
Yeah. Yeah. Which is good ’cause we’ve got RECIPROC® in the dental school, which is good. But yeah, when we were doing clinical skills, I think we maybe done one canal, which was purely hand files. But yeah, every time I’ve been in clinic, it’s been rotary, which is good, but I just don’t, yeah, I don’t know if I’m missing that sort of experience with the hand files. But, we’ll see. We’ll see. 

[Jaz]
And something I didn’t appreciate so much is a taper of your file. So imagine you’re doing a lower incisor and you are using that same RECIPROC® system that you would’ve used for an upper molar. And that lower incisor has two canals, like a buccal and a lingual.

Then imagine how much tooth structure you’re removing to accommodate that file and the taper. So sometimes there is a place for knowing about different taper of different files, different dimensions, and having the K file, the humble K file, which is 2% taper, and to be able to navigate that is, is an important skill and thinking about taper is really important.

But you’re just gonna say, so the premium, the student notes you’re gonna submit as part of this episode. Just to remind everyone as part of this Protrusive Student series, Emma prepares these notes. Every episode we do with Emma, she prepares these notes. They are available to access in the Crush Your Exam section of the Protrusive Guidance app.

We do a manual approval process. So, if you haven’t heard back from us, it’s because we’re still kind of figuring out, are you a dentist? Are you a dentist student? Because we don’t want any members of the public. This is safe space. Please, Emma tat take it away with the notes that you’ve prepared.

[Emma]
Yeah. So when I first started out doing endodontic treatments at dental school, which I’m still very early on in doing a dental school. I find it very hard to know what steps to take things in. So myself and a few other students, we would always just have a little notebook in front of us with what steps, like your steps of your root canal treatment, what files you should generally start off with, what things you need to get out before you start.

Because a lot of the time in Glasgow, we are nursing for each other. And the nurses are amazing. They will help you set up if they have time, but a lot of the time you’re doing it yourself, so you’re getting all your equipment. So I just had sort of everything that I need and just a basic step by step.

So I’ve sort of put that into a document and also just explaining a bit more about why you’re doing the things that you’re doing, not so much just like what you’re doing with it, if that makes sense. Because I think for Endo treatment for me, I knew what I was doing, but sometimes not why I’m doing it.

So I’ve put in step by step by step and just a little bit more about why you’re doing what you’re doing as well. So we’ll link those in this episode as well. So hopefully people can just have that at the side printed off if they need it or make their own wee version. And that’s what really helped me for Endo as well.

[Jaz]
It’s wonderful you took the words outta my mouth because I was already gonna say, ah, but more important than the protocol and what you do is why you do it. Because once you understand why you do it, you know? Any scenario that comes your way, you’ll be able to handle. ‘Cause sometimes, you can’t do a cookie cutter approach sometimes, but when you understand why you do something.

Then you get it. So I love the fact that you have not only the protocol, but why you do each step. ‘Cause that is, like, for example, one thing that used to give me a lot of stress in the past was, if I was using panavia, I love panavia now, but in the early days of using panavia, in dental school like.

Having the laminated sheet, like, wait, what do you do step by step? Like, I need to know this, like, it was stressful for me. It was just like a stupid thing. It was stressful for me, right. To know, make sure we follow the steps to a T. But now when you understand the biochemistry of how these cements work, then you are able to, you just know the flow because of you understand why each step is necessary.

So why you use the ceramic primer stage at the stage you do, why you use the tooth primer in that sequence. And so once you understand why and that you’ve nailed it, so brilliant, we’ll be able to share that it’s only available on Protrusive Guidance. So your first question was about rotary versus K files, and the answer is it’s all good, but the future is rotary.

Just be careful with taper and being able to do the critical steps like a patency filing. You know what patency filing is? 

[Emma]
Yeah, is patency, I get patency and recapitulation mixed up. But is patency file in just taking like our size 10, straight down and taking it just beyond the apex to make sure it’s free of debris?

[Jaz]
Yeah. Yeah. And then recapitulation is like in between changes of files in between, make sure that it’s still not clogged, basically. Right. So that’s something you do with hand files. The other really important thing with hand files is deciding what is your master apical file size.

And so you check, okay, are you at a 30 or a 35 K file, and then you help, that information helps you to correlate what kind of a GP cone you’re gonna finish with and depending on which rotary system you’re using and that kind of stuff. So these are really important, um, skills.

So one top tip is, let’s say you get a blue size 30 K file. So this is like the ISO color system. You take it to your length. Okay. How would you check whether your master apical file is a 30 or it’s 25 or it’s 35. What have you been taught to determine? 

[Emma]
Would you check if for like tug back to see if it fits well at the apical region?

[Jaz]
Okay. So let’s say the canal is 20 millimeters. You take this 30 to 20 millimeters, and then you are checking for tug back, right? Is that what you, so you’re checking for the tug back. See, that’s good, but the issue is, yes, you might have tug back ’cause it that friction’s created, but what if you just try to just poke it through a little bit and it just went through?

[Emma]
Yeah, so using your- 

[Jaz]
So tug back is more used for GP Cone as well, like make sure that your GP cone has a bit of tug back. The way Ian Harris taught me, years ago was you take your file, you put to length, and then it’s just like a tiny little flick. You almost like flick it and see does it actually go beyond?

Because it goes beyond, you know that you need to actually go for a bigger ’cause actually, it’s going beyond your apex or beyond your working length that you determined. So therefore you need to go for the 35 and can that, A go to length, and when it does, then B, does it stop there and it doesn’t go anymore. That for me is, okay, this is my master apical file size. Does that make sense? 

[Emma]
Yeah. So what happens if you flick it and it does go? Does that mean you just need a bigger size? 

[Jaz]
Yeah. Yeah. You need something to stop. So you want something that’s big enough, that’s small enough to reach there all the way to your working length, but not so small that it’s gonna go through.

[Emma]
Okay. Okay, that makes sense. Yeah. One question that I did have for you, and not to skip right towards the end, but about irrigation and manual dynamic irrigation. And we have a certain protocol in Glasgow, but I just want to know if that’s like a universal protocol or what you do in your practice. Or if Glasgows just does something different or if everyone does the same.

[Jaz]
You know, sometimes there’s semantics, like, you know, how they change, like scale and polish to PNPR and all that kind of stuff. Like, yeah, sometimes just semantics. So, according to the best of your knowledge, what’s that term you use again? 

[Emma]
Manual dynamic irrigation. 

[Jaz]
Okay. So what is manual dynamic irrigation to you? And I’ll probably say is GP pumping or something, but what is it to you? 

[Emma]
Yeah, like agitating the irrigant inside the canal just to- 

[Jaz]
How do you do that? What techniques have you been shown? 

[Emma]
So we’ve been shown like using your GP cone, but we don’t have them in Glasgow. Not for the students anyway. But you can get like specific, I dunno what they would be called. 

[Jaz]
Agitation tips, like ultrasonic tips and that kind of stuff too. 

[Emma]
Yeah, the ultrasonic point. 

[Jaz]
So, totally. This has got very good evidence base in terms of being effective and it’s amazing how much cleaner your canal looks by using this. So endodontists are very pro. Ultrasonic agitation of your I irrigation protocol. So good.

So at the very least, I think it’s a wonderful thing to do with GP pumping. You can call it manual dynamic irrigation, but essentially you take , let’s say it’s an F1, F2, or whatever, a GP cone, that’s your master one, and then you’re kind of taking it just shy of the length and you are just agitating up and down, up and down, up and down to, in the hope that, you try and get the best of the hypochlorite into all the nooks and crannies and it flows to get all those hidden bugs and disrupt the biofilm.

Now here’s something that, the same company that makes this, the parent company, the same company that makes the, I think it’s called, again, I’m not gonna say this brand name again. You DM me on Instagram and I’ll tell you these brand names. It’s used in canals and it goes, it vibrates. So it’s not like proper old sonic agitation, but it’s a tip that kind of looks like a plastic paper point, right? And it goes in the canal and just like it vibrates and it does this dynamic activation for you.

So the way you do it, instead of paying hundreds of pounds for this fancy unit that you put these tips on, you can actually buy this cheap, like super cheap one that we use for interdental cleaning for patients. You take the tip off and then you can actually use the tips that are designated for this activation of the hypochlorite.

So again, I’m just cautious ’cause we’ve had a great run on Protrusive so far. I don’t want this to be the end of Protrusive by me revealing these trade secrets that get in trouble. But if you wanna know exactly which ones DM me on Insta or message me on, or DM me on Protrusive Guidance, I’ll tell you exactly which ones to get.

But it’s pretty much common knowledge. And so this is a great and cheap way to do it. But the cheapest and most universal way, no matter what country you’re in, is a GP cone of the correct diameter, just slightly shy of the apex and you up and down, up and down to give it that manual activation.

[Emma]
Okay. Okay. I’ve never actually seen anyone in practice use anything but just the GP cones. I dunno if that’s a new thing or I- 

[Jaz]
But have you shadowed a endodontist? Specialist? 

[Emma]
No. 

[Jaz]
When you do, like, they are like playing a different ball game altogether. Like they are using all the tools and toys and scope and alternate agitation and they’re so slick. They’re so efficient and slick. It’s like they can do the ice closed. It’s really like poetry and motion seeing ended onto seeing good on end onto work is poetry in motion. But yeah, they use, there’s like almost like gold colored ultrasonic tip, they dip it into the canal, they switch it on. And you see the bubbles form and then suddenly it goes murky. Yeah. And then it goes clear. Like it’s beautiful. 

[Emma]
Yeah. And we’ve got, I think he’s an endodontic specialist. He’s only been at Glasgow I think the last year or so. And whenever he’s on restorative main clinic for Glasgow, you want him, if you’ve got a root canal because he says to the nurses, oh, go and get my microscope.

Go and get my microscope. I’ve never been able to use it. ‘Cause I’ve never had him on clinic for an endo patient that’s actually turned up. But it’s good he gets all the tools out and gets everything from his own clinic and lets us have a shot, which is good. 

[Jaz]
That’s awesome. You want tutors like that. That’s lovely. 

[Emma]
Yeah, it is. Good. But again, with the irrigation protocol, is it always like we are taught to do. I think it’s like at least 30 mil, at least 10 minutes before obturation in each canal, irrigating with sodium hypochlorite, then your 17% EDTA, and then a final flush with sodium hypochlorite. Is that pretty standard to you? 

[Jaz]
Yeah, that’s pretty standard to use. What percentage are you using in dental school? ‘Cause we are using like 0.5%, which is quite weak in dental school because it’s so caustic and you can get it on patient’s clothes and cause you know, extrusion and when you are learning they just want to play it safe.

So like the efficacy really improves. The stronger you go beyond 3% is good. Some endodontists use 5.25%, but obviously at that level of concentration for students to use. I understand why they have reservations about that. So, do you know, what concentration are you using? 

[Emma]
We use the 3%. 

[Jaz]
Okay. That mean that’s good stuff. That’s a proprietary, hypochlorite. That’s very good. Yeah, very effective, very dangerous as well. So you gotta be careful. Has anyone got any hypochlorite on a patient’s clothes or something? 

[Emma]
No, not that I know of. Not yet anyway, but there are, you know, if you go round and you’ve got your thumb on the plunger, you’ll get shouted at.

[Jaz]
So yeah. Great point there. Never have your thumb on the plunge. Yeah. It should be your index finger. Is that who you even taught? 

[Emma]
Yeah, your index finger. Yeah, so we’d get around for that one. But in our preclinical skills class, we did a lot of endodontics as well and a lot of emphasis on safely using hypochlorite and injuries and things. And I’ve actually seen one in practice as well, which was not good. 

[Jaz]
Yeah. Patients come in and they look really bruised and very swollen and there’s an episode we did called the 10, I think the 10 Commandments or something. And one of the scenarios we tackle was a hypochlorite injury.

So we’ll make sure we link that episode to, for everyone to listen to. ‘Cause so many great scenarios we covered in that podcast. One of them was a hypochlorite injury and how to manage it. But yeah, you gotta, basically, you gotta be careful, but you guys are using really good stuff.

So the benefit of hypochlorite is it removes, it kills the bacteria, but it also dissolves tissue. No other irrigant. Yeah. Does both so well. And this is a highly researched topic. They’re really trying to find the one arrogant solution that rules a more kind of thing, but hypocrite is still king. And people always say like, rubber dam, right?

Rubber dam is like, we haven’t talked about it, but doing root canal without rubber dam is like doing heart surgery in a toilet. Like literally that was the way it was explained to me as a student. And I think it’s so, so, so key. Now, some people say that I have good isolation, I use cotton rolls, and I don’t, there’s no chance of any saliva getting in under my watch.

‘Cause we’ve got high volume suction, we’ve got cotton rolls, but I’m like, okay, fine. There’s no saliva, which is full of bacteria going in the canal. Well done. But surely, surely, surely, surely you’re not using 3% plus hypochlorite on that patient, therefore. The whole point of rubber dam isolation is to facilitate you to use these strong agents so that you can, if you are using corsodyl mouthwash for Pete’s sake, if you’re using corsodyl mouthwash, that’s doing nothing right.

And no wonder you can get away without using Rubber Dam. And so yeah, it’s great that you’re using the correct irrigant, Hypochlorite at a wonderful percentage. You guys heat it. Do you guys like heat the hypochlorite? 

[Emma]
No, no. 

[Jaz]
So that’s another technique you can do. You can heat hypochlorite to get even more effectiveness of your hypochlorite. And then do you know that the sort of rationale and the mechanism of action of a 17%? 

[Emma]
So EDTA is like a chelating agent, and so like all the smear layer that you’ve created from your canal preparation, it helps to sort of remove that smear layer so that you can get in contact with those tubules really well.

[Jaz]
Yeah. Opens the tubules, which is why you then do a final flushed hypochlorite. ‘Cause now you’ve opened the tubules. You want the hypochlorite to be able to go in and well the endodontists, because they use a warm vertical compassion, they use like hydraulic pressure with this hot GP, you have the best chance of the GP going into these accessory canals and into the tubules. And so that’s why we use that. So it’s a winning combination.

There’s a really good paper. I’m gonna recommend everyone checks out. There’s a really good paper by Paula Ng. Paula Ng. It’s a fairly classic paper and it looks at like loads of root canals, and they try and find out which elements of the protocol significantly influence the success rate. Do you know about this paper? 

[Emma]
I don’t think so. 

[Jaz]
So like for example, having a sinus tracted at the beginning, there’s a certain percentage, I forget at one point I used to know, but having a sinus tract at the beginning, it reduces your endodontic prognosis by 20%, just by the presence of it basically.

But then when you heal it, then that changes your prognosis further. If you use EDTA, then it improves your success rate by 10% or something. I think it was 10%. But like there’s various factors which all add up. And that Paula Ng paper really does a wonderful job of summarizing it.

[Emma]
And just on the back of that, just as a gossip, I suppose I remember I did a locum in a practice, I won’t say where or who, but they were using Milton like Baby Milton which I was like, subpar. But you know, I’m just here for one day. Like, it’s not like I worked there permanently. They were using Milton and Chlorhexidine for their root canals.

There was no rubber damage sight. And when they were taking a, like into appointment, radiograph, they put a clamp on. They put a clamp on the. And then took the radiograph and I had no idea. 

[Jaz]
So you know why they did that? You know why they did that? 

[Emma]
Yeah. It wasn’t until I spoke to someone else about it, I was like, why are they doing that? Just so that it looks like they had rubber dam on, on the radiograph. 

[Jaz]
Exactly. 

[Emma]
It’s so bad. It’s so bad. 

[Jaz]
A hundred percent. So this is you, this is the secrets of the things that happened. So how much endodontics is happened in the real world. Like in that way. It’s a shame.

And so here’s a crazy thing, Emma, right? I was in India. I was on this course in India, and next door there was an endo course. Because this is when I lived in Singapore, right? And I thought, wow, it’s great value to go to India while I’m in Singapore. I get to visit India, but also at the same time go to some CPD there, which was like amazing value.

But then the next door they were treating, they were literally treating an endo students. There was like seven dentists there learning endo dentists, right? Not a rubber dam in sight. 

[Emma]
Really? Wow. 

[Jaz]
And, so I’ve just googled Milton’s solution in terms of percentage. So, typically 1%. So it’s not too bad considering, 0.5% what we use at dental school.

Okay. So the fact that they’re using a form of hypochlorite is better than using corsodyl, right? So fine. But, rubber dam, it’s a necessary because saliva is full of bacteria. But the naughtiest thing here basically is the use of the clamp for the radiograph so that it basically medical legally that I use rubber dam, look at the clump like I use rubber dam kind of thing.

So it’s naughty and I think the kind of people who listen to this podcast and who engage and who comment and stuff, we are so far away from that, that for some of us, it’d be like, what? Really? Do people do that? Because I like to think that we are a collective of the most forward thinking and people we generally want the best, our patient.

Like, would you do that on your family member? You want your endo, you want this endo to succeed. The funny thing is, endo a bit like perio. The host response is the real winner here, and our job at endodontics is to disinfect. We can never sterilize a canal. We want to disinfect and create the environment to allow the body to heal, which is why I see in my population of 60 plus patients, which I have so many of. I see these silver points. Have you seen the Silver Points before? 

[Emma]
Silver Points. 

[Jaz]
So before they used to use gutta-percha, GP, there was like these silver points in canals, right? And it’s like they have this like classic look like a, they literally look a super radio opaque point in the canal and they’re like super short.

Yeah, they’re like really short the apex usually. And you think, and there’s no infection around the tooth like there, so this quote unquote dodgy root canal has been there. Right, and sometimes you see something that’s poorly obst, it’s single file plenty. It’s like floating in the canal space, but there’s no infection, right?

So you might just by using saline as irrigation, by using, by just sticking a couple of files in there, sticking a GP point cone in there. Maybe I’m just postulating, maybe you will get 50 to 60% success rate just by closing it up, giving a coronal seal, and you might get 60% at five, 10 years. Right?

Still, that’s a lot of failure. But when you are trying to aim for the success rate, the endodontics does thankfully enjoy, right? Which is 90, 95% plus done well and in life. That’s where we want to be at. That’s what we wanna aim for. And that’s those little things, which are the big things, right? By rubber dam isolation, doing it properly, not just for the radiograph, right?

Using the correct solution. And just, if you get the basics right, it’s like Pareto’s principle, right? 80% of your effect comes from 20% of endodontics. So 20% of endodontics that have the 80% effect is rubber dam isolation. Choosing hypochlorite and respecting the structure of tooth and not being overzealous with being conservative. If you do three things, then that is a pato principle, endodontics, you get the 80% success by just doing those three things. 

[Emma]
Yeah. So if you are doing these three things. What are you looking for for a success of root canal treatment? What do you class as a success? What hallmarks are you looking for?

[Jaz]
I love this question, right? Because classically, when I was at your stage and a young dentist, we have this perception that it should look sexy on the radiograph. So at your stage, I was looking at the radiograph, right? The thrill of the fill. Okay. You put your GP in and it looks as though it is to length and it doesn’t have any voids in it.

And we think, wow, this is a success. Right? But the thing is, when you see a radiograph, the radiograph cannot tell you whether rubber dam was used, whether hypochlorite was used, whether the coronal seal was really that good and what protocols were used in terms of this disinfection. So yes, the radiograph is one factor, and if you look at the European guidelines.

The GP cone obturation should be within two millimeters of the radiographic apex. I believe I need to revisit these guidelines again. And then there should be no unfilled canal beyond the gp. Lemme say again. There should be no unfilled canal beyond the gp, and that’s a really good one to look for.

But again, these are just a factor, right, which don’t tell you the full story. So for me, the success is if there was a sinus tract present that that sinus tract, which for the students who are early in their career, it’s like having a pimple on your gum and the source of the infection of the pimple. Have you seen the sinus tract before? Emma? 

[Emma]
Only like as a nurse. I’ve never seen one on a patient myself. 

[Jaz]
So sometimes you can actually, stick your GP cone into the sinus tract. Let’s say the sinus tract is between two premolars and you don’t know which pre-, they’re both premolars look a bit dodgy, and you think, hmm, which one’s the infected one? You can put a thin gp point in there, and then until you feel a stop, and then you take a radiograph and it’ll show you on the radiograph, which is the culprit. Okay? So anyway. Sinus tract. If the sinus tract is gone, that’s a success.

If it’s no longer TTP, i.e., tendered to percussion, that is a success. If there was any peri-apical pathology that is now healing. Okay, so at six month mark, you’re seeing some healing and the patient has no discomfort from it. These are all factors we look at. And so there are success parameters and also there’s survival, which is fascinating, right?

Success versus survival. A tooth could be like, still technically have some elements that we would think, oh, there’s a failure. There’s still unfilled canal. There’s still a bit of radiolucency there, but it’s still functioning in the patient’s mouth. The survival data is also very interesting ’cause it’s causing patient no issues at all.

They’re still chewing with it. We still see this black area and we think it’s a failure, so we’ve gotta get clear what does it look like for us? And I think it’s good to know both. But ultimately, is the tooth serving the patient in some way and the patient’s able to, let’s say, go on holiday and not worry about this tooth.

I have some patients who they feel like they need to go abroad with antibiotics, otherwise they worry this tooth will flare up. That’s not success. Success is being able to go in holiday and not having to worry about that tooth. And if it’s something arises, it’s like a total shock. That to me is success.

[Emma]
Yeah. Because we’re taught all about these hallmarks to look for on a radiograph pre and six months down the line, you know? But if it’s still sore, then how can that be a success? There’s different, what did you say there? It was success and to survival. 

[Jaz]
Survival. That’s right. So the success is a bit more strict criteria, right? And where survival is like, is it in the mouth, is it contributing to the patient’s function, and without causing any major symptoms or not, like something that’s causing active symptoms to the patient. 

[Emma]
And then if you have a situation where you’ve provided a root canal treatment on a tooth that was symptomatic, how do you approach the conversation with the patient about having a cuspal coverage restoration after that?

Like, how long do you wait until providing a crown? Because ideally, I know you want to do it within a few weeks, if you can. Then there’s money involved. And then if the root canal fails, how do you approach that? That’s a tricky one. 

[Jaz]
This is such a beautiful question. I think this will be the last one to tackle then today, but this is such a great question. Okay, so let’s end on the high. This is a timeless debate, right? What point do you go for your cuspal coverage? So I think first we need to go back a bit and decide when do we need cuspal coverage and when do we not? So, in a few instances, for example, if it’s an upper incisor that had just like a third bit of trauma, it’s still structurally you could just do a class four and fix it, for example.

So in a medium sized class four, and then when you do your access cavity, palatally and it says, one canal and you’re able to fill it, you don’t need cuspal coverage very often. You don’t need to crown that tooth just ’cause you had root count treatment. If there’s enough tooth structure. When it comes to molars and pre-molars, if it’s just a class one.

You still got good rigidity and two structure remaining, and for some reason it was like a deep class one caries and the marginal ridges are intact in most patients, not all, ’cause some patients are very high risk or they’ve got existing crack line stuff. In most patients you don’t need cuspal coverage.

It’s okay, but to be honest with you, the vast majority of cases, they’re already like huge MOD amalgams or a do caries that would probably benefit from cuspal coverage. So vast majority of time we need cuspal coverage because there’s marginal ridges. The strength of tooth really comes from marginal ridges and quite often the other reason actually, do you know the other reason why a lot of root filled teeth will benefit from cuspal coverage? We talked structural loss is one, but there’s one really key thing that I think is underrated and needs to be talked about more. 

[Emma]
I suppose, like the tooth being brittle, that’s the same as the first point, isn’t it? 

[Jaz]
Yeah. So we brittle, maybe the arrogance make the tooth brittle, but actually the crux of it is that there’s a thinner, weaker tooth structure. Because once you strip back the tooth and make it naked and get rid of all the restorations. And now you’ve made a access and you’ve canal, you’ve widened the canal. If you look at how much tooth structure is remaining, it can flex and it can break, so it’s weaker. So that’s one structural. Yeah, but there’s one more.

[Emma]
Is it just to prevent reinfection? 

[Jaz]
It’s a coronal seal. But, what if you did a really well bonded composite and got a coronal seal. I think sometimes indirect restorations can help. I get that, but actually the answer is proprioception. A third of your tooth  proprioception is provided by the pulp.

The PDL does the heavy lifting, but the pulp is important. So the best analogy, the best way I learned this again, Pascal Magne taught me this is imagine you have your upper right first premolar, okay? And then you are gonna bite in your fingernail, okay? And you bite, bite, bite, bite, bite, okay? And very soon you’d feel like pain.

You’ve overloaded your tooth. That’s a  proprioception from your PDL and from your pulp. If that tooth is root filled, you’re gonna invite right, bite your, are suddenly able to load it more before it talks back to you. Says, hold up a minute. Okay, so this is a recipe for disaster. ‘Cause now you have a weaker structure that, that needs more load to give some sort of reaction.

And therefore this is asking for it to be cracked and broken. Yes, cuspal coverage very often is needed. And so at the very least, I like to do a pre-endodontic buildup. So I used to back in the day not appreciate the stage so much and I used to like drill through old amalgams to try and find the canals and I’d leave the amalgam there and, but actually what you need to do first.

Strip back the entire tooth, make it naked, go, go, go all the way, like remove everything, then caries removal, then put a major span on, get your pre endodontic seal or pre-endodontics restoration. There’s a big block of composite. And then you’re gonna do your endo through that. This is the gold standard that I’ve learned now.

And at that point you can actually bring the cusp down and then overlay. Now you have a direct cuspal coverage, right? But from your composite, you’ve now also built a coronal seal. You’ve got rid of the old tooth structure and you’ve made those cusps shorter and fat, which is less flexing and made it stronger.

And then now, even if the patient does disappear for about three months or a year or whatever, at least now you’re less worried because you haven’t got crown on there. Whatever. You should still probably in vast majority of cases to meet the aesthetic demand and function demands, probably upgrade to a lithium disilica or a zirconia or whatever you might go, okay.

But at least that’s better than leaving the cusp as they were. At least with that composite, that cuspal coverage composite, you give that to some protection while your decision making about what, which indirect restoration to provide. And the other, it answers the other question of how soon should you do it?

Well, as soon as possible, you need to provide the coronal seal. Yeah, as soon as possible where indicated you get to give some cuspal coverage. So nowadays with composite, you don’t have to wait to give those two benefits. You can always upgrade to indirect in the future. And then you said about, what if the root canal fails, well, if done well, root canal does enjoy 90% plus success rates.

So this is something that you tell the patient that, look, you know, this is the success rate of working to, if it doesn’t work for you, then it’s a shame we’ll have to extract that tooth, but it’s still better than removing the tooth and going for an implant in the vast majority of scenarios.

[Emma]
Yeah. So I guess again, like all just comes back to consent and I know you like to ask your patients, like how much of a gambler they are and quote them all these success rates and then I suppose as long as you’ve told them about all the risks and everything- 

[Jaz]
So let’s recap that, right. If you’re unsure and you’re not sure which way to go, and the patient’s ing in our ring, you say to the patient, look, if you spend a significant amount of money, let’s say a third or up to a half of an implant. ‘Cause it varies in every country. So let’s talk in those terms, right?

It’s a fraction of an implant, but a sizable fraction of an implant on root canal, a pre-endodontic restoration, and a crown in the future. And it fails. Which is less likely to happen by say, so more than likely it’ll work. But if this does happen, okay, would you be like, well, at least I’m glad I tried and now I’ll save up for an implant and I can arrange this.

Or would you really regret that? Ah, I wish, I really, really wish I went for an implant and not this. Because I would tell them that, look, if it was my family member, then having your tooth has a value even to keep a tooth on five, 10 years. Yeah. There’s value in that. Then going straight for an implant.

But as long as the patient understands that it’s their risk to own, how would they feel? Imagine that it did fail. How would they feel if they feel like, you know what? I’m glad I gave it a shot and I tried to keep it, and I was a bit, a little bit unlucky in that regard, then they’re a bit more understanding that way.

[Emma]
Yeah, that’s fair enough. And I know you said that was the last question, but do you have a different consent form for root canal treatment? 

[Jaz]
Yes, absolutely. Yeah, the endodontist has his own one. We talk about file separation. We talk about all those things, but like with everything, everything has to be customized, so you should be able to draw on the consent form and stuff.

And mine’s nothing fancy. It’s like a template handed down for me from wherever. It’s the nothing fancy. ChatGPT can write you one in, 10 seconds, right? Nowadays. So I don’t think it’s a consent form. It’s the way you communicate and the way you customize that consent for that too. Like there’s no like if you have a upper central incisor root canal, and you are dealing with a beautifully straight wide canal, okay, I’m sorry, but if that file separates in that canal, right? Yes, it’s in your consent form, but that’s negligent. A file should not be breaking in that tooth. That is silly. Yeah, it should not be happening.

All right. If it’s a curved, lower molar, totally. You need to emphasize that more on that form. That, Hey, for this? Hey, patient, you are high risk of this because you’ve got a curve. Here’s what I’m gonna do to mitigate it. But you need to understand that actually it’s your tooth that’s curved.

Okay? Whereas in that single central, with a beautiful straight one, it’s very unlikely that this is gonna break because it’s a nice straight canal. So it’s very, extremely rare and unlikely. So it needs to be made bespoke. They need to understand which risks are real for them, and which ones are just on paper. Academic. 

[Emma]
Okay. That makes sense. Yeah. 

[Jaz]
Alright, great. Emma, thanks for asking. I’m really impressed with your insights. Some of those questions were really good. I hope you feel a little bit happier with that topic overall. 

[Emma]
Yeah, yeah, that was good. Yeah. Some good tips and tricks in there as usual.

[Jaz]
I think the theme of this episode wasn’t so much technical then use this file then how you move a ledge and stuff. ‘Cause I think that’s something that you can only learn hands on. But I think we approach it from a bigger picture perspective for Endo, which I think is helpful when you’re starting out and you are revisiting.

[Emma]
Yeah. And I think that’s why, for the notes, I focused more on actually doing the endo and that side of things. And today was just a general, some questions that I had. Really. 

[Jaz]
Good. I mean, you asked all the good questions about the role of irrigation, the sequence and the necessity for cuspal coverage. The role of rotary K file, all that kind of stuff. So I think your questions were excellent. What do you think we should cover in next month’s student episode? 

[Emma]
So next month I had always wanted to do a bit of a medical history episode, more just like key drugs in dentistry. I think this is more relevant maybe for people who want a refresher, but like very early on in dental school, maybe when you’re starting to see your first patients.

I remember being so afraid to take a medical history and do a systems inquiry or do I do this approach? So I think talking about the key components of a thorough medical history and talking about maybe some key drugs in dentistry as well. 

[Jaz]
Okay, let’s do it. But I’ll tell you that right now. You probably have spoken to so many dentists you work with some of these things like medical history, like you’re so hot on it when you’re a student. When you come in the real world. Okay, actually, you’re gonna have more knowledge than me. All right? And so we’re gonna do a role reversal. You are gonna be schooling me about medical histories.

Okay. But I’ll give you my flavor and perspective experiences, but I have enough humility to appreciate that. You probably know more medical histories than I do, Emma. Okay. And so I’m excited to learn from you. So let’s, look forward to that one. 

[Emma]
Yeah. Perfect. Okay. We’ll do that.

[Jaz]
Thank you so much, Emma. 

[Emma]
Thank you. 

Jaz’s Outro:
Well, there we have it guys. Thank you so much for listening all the way to the end. Once again. How good of a job is Emma doing? I want some love for Emma. So whether you’re watching this on Protrusive Guidance or YouTube or listing on Spotify, find us on Instagram if you want.

And just send some love to Emma. I think she’s doing a wonderful job of asking the right questions. And I hope you are enjoying this Protrusive Student series. Remember, we do have a crush your exam section in the app. Once you gain access to the app, just message Mari, MARI, Mari Benitez, she’s our CPD Queen.

She also is the gatekeeper of the students’ freebies. So be sure to message Mari. The website, of course, is protrusive.app. That’s protrusive.app, and it’ll be great to see you on the platform. It’s just magical to have the community of the nicest and geekiest dentist in the world. One of our members, Hannah, from the States, she recently said that she’s making it like a routine to spend half an hour to 40 minutes a day on the app, which is so much better than doom scrolling on Instagram and TikTok, and she’s noticed her own words.

She’s noticed a significant improvement in a quality of a dentistry and an enjoyment of dentistry. Now, that just means everything to us. So if you’re not already on the app, check it out, www.protrusive.app. Otherwise, I’ll catch you same time, same place next week. Bye for now.