I Hate Cracked Teeth with Kreena Patel – PDP028

Jaz’s Introduction: Today I’ve got endo Queen, Kreena Patel on the show today and we’re talking all about cracked teeth, something as you will hear, I absolutely despise in general practice, I think it’s the bane of my existence. It’s one of the most difficult things to sort of diagnose sometimes. And the amount of conversation that’s involved with the patient, the amount of sort of discussion and complexities and nuances and possibilities your tooth might not be able to, might not even be able to save your tooth, we might have to put a crown on. But if then it fails, you might end up have to remove it. You may or may not be better off having an implant, the success isn’t that good. I’m not even sure which tooth it is. These are sort of things that you sort of end up discussing when it comes to cracked teeth. So we’re going to be discussing things like how far into a canal orifice does a crack need to extend before you look and say, You know what, this is unrestorable and when discuss about diagnosis of cracked tooth, which is one most challenging aspects of cracked teeth. And we’ll also discuss about how Kreena suggests is managed endodontically and also buy us in terms of cuspal coverage. So I hope you enjoy the episode. The episode as well as everything from Episode 20 onwards is going to be eventually on Dentinal Tubules for enhanced CPD, so thank you Dentinal Tubules for quality assuring my CPD. So if you wanted to get your CPD hours in, then you can go to Dentinal Tubules search Protrusive Dental podcast and answer a few questions, acknowledged the aims objectives and they are you will have CPD, enhanced CPD for this meeting. We know with all the outcomes written there. It’s all well and proper. So the Protrusive Dental Pearl I have for you is an endodontic one. And it’s the one that actually Kreena gave me in the middle of the episode actually, she told me when we’re using a tooth slooth, which is one of those rigid plastic thingies that you put on the teeth, and you get the patient to bite together and what it does is it flexes the tooth to then see if you are confirming the diagnosis of cracked tooth basically is essentially how you do it. And Kreena talks a little bit more about that. When you’re using that one thing that I don’t do as much at the moment I had an occasion I found Oh yes, this helps. But I never really made it protocol was to actually once you get the patient to bite down on the tooth slooth, you jiggle it a little bit, just jiggle it because that sort of jiggling can then sometimes be the difference between being a negative result and a positive result. And that positive result is obviously important in your diagnosis. So the Protrusive Dental pearl donated by Kreena Patel is when you’re using a tooth slooth, make sure you jiggle it. So I hope you enjoy the episode. If you’re listening to it, then awesome. If you’re watching on YouTube, then even better because there’s at one stage a photo of a cracked tooth that I show. So if you are listening, then reference back to the video version on YouTube and igtv to look and assess that clinical photo of a crack that I will show because it’s an interesting point that she raises about the width of the crack. So sometimes it’s helpful to see the crack. So let’s all learn from Kreena.

Main Interview:

[Jaz]
Kreena, Kreena Patel, welcome to the Protrusive Dental podcast. It’s great to finally have you on and we’re going to talk all things about cracks today. How are you?

[Kreena]
Yeah, very good. Thank you so much for having me on.

[Jaz]
No, it’s really something that’s been a long time coming and for to put some context into this right now. We’re in the middle of COVID-19 lockdown. So if you’re listening in the year 2025. That’s what’s happening right now. And Kreena is going to be giving us some expert knowledge and advice about cracked teeth because this is the time to sort of gain more knowledge and skills so that when we go back into work, we’re fully charged and ready to go. So Kreena, for those very few people out there in the world of dentistry who don’t know who you are, can you please tell them about who you are, what you do, but I’m going to give you a little introduction in sense that you are one of the most proactive, most approachable, friendly and giving endodontists I’ve ever met. So now over to you.

[Kreena]
Oh, that’s lovely. Thank you Jaz. And yes, I’m a, I graduated for Manchester 2010. And following a couple of years in general practice doing DFT. I then moved on and did my specialist training at King’s College London, and I graduated from there in 2016. So since then I’ve been working mainly in specialist practice. And so I work based over in Croydon and in Reading. And I also teach one day a week on the MClinDent specialist program for King’s College London as well. So it’s quite nice having a little bit of variation in my week, which is always nice. It’s also quite nice giving something back so being able to do a little bit of teaching, whether that’s lecturing or working at Kings, just keeps you nice and fresh and motivated.

[Jaz]
I can see that you enjoy the education part of it from you know based from what I see on your Instagram and I think you’re something, I can sense something you enjoy.

[Kreena]
Oh, definitely. Yeah, I mean, I think when everyone start, endo’s never the thing that you know people love, but with practice, I think endo can be really fulfilling, there’s so many different aspects to it. And I feel like every case I treat, I find something different or I learned something different. And endo has as well as being obviously quite restorative speciality, there’s quite a lot of surgery involved in it as well. So it’s got quite a good variation. And the surgery is, you know, fairly complex surgery. And so I just think there’s, things in there that mean that you’ll never get bored. So, yeah, I highly encourage people to think about it.

[Jaz]
Brilliant. Two things I want to ask you before we talk about the main theme of cracked teeth. And the two things is one, what percentage of your practice is surgery at the moment? And the second one is, how big of an impact has CBCT made in the last five years in your daily practice?

[Kreena]
And so not a very large percentage of surgery, actually, I’d love to do more. And it’s just when you learn about doing endo surgery, you realize case selection is so important. And the majority of cases can be treated nonsurgically. So as long as they’re treated well quite a significant portion heal with root canal treatment or root canal retreatment. So, if most of my week is doing that, I’d say about 5% is surgery, I do a little bit more at my teaching job where I supervise surgeries for the postgrads so that keeps me quite involved in it. But yeah, I mean, I wish I would do more, but it’s just that, you know, most things heal without surgery, which is a good thing for the patient, I guess.

[Jaz]
And then how about CBCT?

[Kreena]
Yeah, I mean, CBCT had a massive impact. It’s almost like a whole lecture. There’s so many applications to CBCT and endodontics. From you know, whether it’s diagnosing periapical lesions, because quite often on radiographs, they’re 2d X rays. So you know, sometimes for patients with difficult you know, signs and symptoms, we can’t really diagnose properly. A CB CT game changing because you suddenly see where the problem is, because we see significantly more periapical lesions on CB CT, then pair of radiographs, also things like resorption. And so things like internal resorptions, external resorptions, you know, it allows us to plan these cases without, you know, going in surgery, or doing any invasive treatment, we can instantly see what we’re looking at. So it’s game changing for that. And even things like endo surgery, it’s fantastic. We can plan the treatment, we can see the proximity of lesions to the sinus, mental nerve, ID nerve, that allows us to do more complex treatment, you know, surgeries on lower molars, which we probably wouldn’t have taken the risk to do before. Full mouth, fantastic for trauma. So many applications for CBCT and endo. So we’ve actually just bought one for Oaktree Dental practice. And you have to be a little bit more careful when choosing cone beams for endodontics. Because you need a much sharper image compared to for implant surgery, because we’re looking at obviously tiny canals. And you need to see that sort of detail. So it’s a little bit more difficult to pick a scanner when it comes to endo.

[Jaz]
Yeah, we do have a in the Richmond practice, there is a very good CB CT scan with an endo mode. And I think that’s what you know, it’s just higher detail in that area for when you need it. So it is different. So on the topic, I mean, I’ve got a list of questions, I want to ask you about cracked teeth, but now on the cuff of cracked teeth, and cbct. You know, when you take a PA and we all do this, we take a PA and we show the patient and we suspect cracked tooth. And well the first thing we say to the patient is, well, I need this x ray, but I’m not expecting to see the crack on this x ray. And we all say that, where do you do see cracks on CBCTs?

[Kreena]
It depends on the size of the crack. So there’s been quite a lot of research that came out on this and the initial research said, we can’t see cracks and but what they were doing with that research is they were making the cracks a little bit wider than what we would you know, something that we would see in the mouth, for example, that we would need a cone beam for. So initially, a lot of the studies said you know cone beam is very useful for diagnosing cracks. And the latest studies were making very hairline cracks in teeth and then looking at that, and what we found is actually on cone beam we don’t see cracks at al, very fine cracks that is on a cone beam. In fact it because cone beam has a smaller resolution than periapical radiographs, we’re less likely to see it on a CB CT compared to a radiograph for example. [Jaz] All right [Kreena] and the thing that we do see though, is we quite often see the bone loss associated with a crack. So if we have a vertical root fracture, you know, quite often clinically we get a localized deep pocket associated with that. And that would be you know, there’d be bone loss associated with that and those fine details we see a lot better on a cone beam. So the associated signs there but not the crack.

[Jaz]
Well, I think it’s fair to say that if you can see a crack on the CBCT that tooth is probably for the bin

[Kreena]
yeah [Jaz] Fine [Kreena] That is exactly right.

[Jaz]
So the reason why I chose a cracked teeth is that although I love clinical dentistry, I hate cracked teeth with a passion, I hate dealing with it. Because it’s just there’s so many challenges and variable. So the way I say is, if there’s a cavity in a tooth just caries with no associated crack, there is a degree of predictability in the sense that when you’re communicating with the patient, you can be a bit more definitive that, okay, there’s a low chance or medium chance, depending on symptoms, stuff, whether you may end up needing root canal treatment. But when it comes to a cracked tooth, there’s so much explanation in like a flow chart you have to explain Well, if you then end up having pain, then we can hold your root canal. But if the crack is too big, then we can’t save it, we’ll only really know at this point. So I find it’s just a nightmare in that sense. So that’s why I’m going to speak about and so

[Kreena]
And we say much more. I don’t know about I mean, I feel like I’m treating, one or two cases a week, which never used to be the case a couple of years ago. Yeah, it’s definitely getting more and more. Probably because people are more stressed. You know, I mean, I’ve got cracking my teeth. And then it’s probably from all these exams that I’ve sat but

[Jaz]
Are you parafunction or what have you, do you have a history of parafunction?

[Kreena]
I can’t say. I don’t tend to night grind. I think I used to do but I definitely clench a lot. And my Yeah, my lower sevens got a crack in it.

[Jaz]
I’m going to ask you my list of questions. So we’ll have them have my phone out, please don’t think I’m texting someone. I’m actually looking at my questions. Okay? So if a patient comes in how do you manage your situations where pain is difficult to localize, and you’re in a diagnostic dilemma, and you suspect a crack? What is the sort of your standard protocol of ‘Okay, I suspect cracked tooth, I don’t exactly know which tooth’ because sometimes you just can’t see which tooth it could be. So talk us through how you’d manage that.

[Kreena]
But I think just starting from the basics, because I find that really helps a good history before we actually start the exam. So I run through SOCRATES, and so Sites, you know, where they think it’s coming from, and there’s been studies that have shown that, you know, patients that think it’s coming from a certainty, quite likely it’s coming from that. So, I mean, I think, you know, having a good conversation quite often with these cases, the patient isn’t sure they might, it could be this one, it could be this one, I think it’s more likely this one. And so I think that is very important, actually just get, you know, right from the onset. And the second is the Onset. So when it started, because sometimes patients they present to you with irreversible pulpitis, and, you know, it’s very severe pain. But if you ask them the history, then, you know, they might have said, you know, I had pain on biting from around this tooth for about a year or after that restoration was done. And it never felt right. And now I suppose a bit of pain. So I think if that really helps, and quite often you find with patients, they’re not willing to divulge that information. And they just say I’ve got a bit of pain, and then you get on with it. But I think the history is actually very important. And even the radiation, so you know, if they’ve got, for example, ear pain associated with it, we’re now thinking lower molars, potentially, if they’ve got pain in their eye, you know, canines, things like that. Even exact things that are stimulating the pain, so hot and cold, because those things will help me during my clinical examination. So when it comes to a patient and their exam, I start from all the basics. So what’s tender to percussion, starting from the adjacent teeth, which aren’t tender, and if you know if there’s two teeth, which are both tender to percussion, and then again, I’ll try and look for cracks. Magnification is really important. So I think with cracks, you do have to be using loupes, and a light if you can, ideally, a microscope is lovely to have that I think loupes and a light you see, you know, a lot more than just with you know, normal vision.

[Jaz]
What’s the minimum level of magnification you think someone should be using for exploring a crank? Do you have an opinion on that?

[Kreena]
Yeah, I mean, I think if you’ve got loupes, it’d be five times magnification because it’s very difficult to see where the crack extends without that sort of magnification because you might think it’s a lot more coronal than it actually is because they go very hairline as they traveled down the tooth and say, I think five times is the absolute minimum when [overlapping conversation] [Jaz]
The advice I give to lots of young dentists, students and stuff coming out and they’re buying the first pair of loupes is just skip the 2.5 and 3, go straight to the five because you know I went five in that, I now want eight or something you know, also on Fridays where I get to use a scope I’m like, Oh, this is so much better. So you know that’s one side thing I want to say, more magnification the better with good lighting as well as you said,

[Kreena]
Yeah harder to get used to in the first instance but within two weeks, I think you’re there you know, so I totally agree with what you’re saying there. And also the bite test. So using a tooth slooth, so testing individual cusps, when they get when they bite down on the tooth on an individual cusp. I tend to jiggle the end of the tube slooth, because that sort of gives lateral pressure on the cusps. And I find that very useful. And

[Jaz]
Can we just talk about the tooth slooth actually, because people actually use it without knowing the proper way to use it. So the, you know, the curved or spoony side and whatnot. And also want to answer this for me, which is, is there any evidence suggests that the using an actual rigid tooth slooth is superior to what a lot of GDPs use is a cotton wool.

[Kreena]
Yeah, I think the problem with cotton wool is you don’t get the same sensation as when you use a tooth slooth, so tooth slooth tends to separate the tooth a little bit better because the so as you mentioned with the tooth slooth, you can have one end which has got a little component that’s meant to sit directly on each of the cusps individually. So you test one at a time. And so you put the cup end on the cusp tip, get them to bite down and on the flat end, and then you jiggle the end of it. And what that does is it puts lateral pressure on each of the cusps individually, which I think cotton woll just really can’t do. So I think that you know tooth sloot aren’t very expensive, but they total game changers when it comes to diagnosis. So I definitely recommend so.

[Jaz]
It’s a good tip you give them of jiggling. I think that is something I don’t always do. So I think that’s a good point.

[Kreena]
Yeah, I mean, some people will feel it instantly. But some people it’s the jiggle that does it. So it’s a good idea. And I also find sensibility testing really good. So the other thing that I mean I all these things that mistakes that I’ve made in during undergraduate I never got taught how to use a tooth slooth. With sensibility testing, it was always ether chloride and the [inaudible] No, exactly, yeah, the teeth, I mean, it felt great about -5 degrees. Whereas if you’re using something like endo frost, it’s -50. And so you were much like you know, much more likely to get a good response with something a lot colder. So, Endo Frost is the first thing I pick up. There are some cases of you know how you mentioned, it’s very difficult to diagnose where the where the pain is coming from. And a good tip that I’ve learned recently is I tend to use a hot test. So you know, you’re taught you need to do get some warmed GP and put it on the tooth, but that doesn’t work very well at all. So what I tend to do is I’ll get my nurse to boil the kettle, and then I will put the warm water in an endo syringe and not boiling hot, obviously, but just warm, fairly warm. And then I will individually isolate each of the teeth on that quadrant with rubberdam and put the hot water on it. And you know what the patients that tell you they’ve got hot pain, instantly, you’ll know which tooth it’s coming from. Because they’re the ones you know, with irreversible pulpitis they find it very difficult to differentiate which tooth it’s coming from. It’s quite a little bit painful for them, obviously, you need to tell them it’s not very nice in terms of doing it. But I get the nurse ready with the suction so she can suck up the water as soon as it’s done. But I find that test really useful. I had a couple of patients referred to me recently that the dentist hasn’t been able to diagnose which teeth it’s coming from. And the only way that I managed to is do it with that test. So

[Jaz]
That’s a really good tip for anyone listening use the hot water in a syringe, isolate each tooth with rubber dam and you know that might figure out which tooth it is. I have a story whereby I was dealing with a patient who ultimately end up having cracked tooth but the symptoms were severe pain, irreversible pulpitis type, apical periodontitis, and we’re trying to figure out is it from the top, is it from the lower and an upper right first molar was very TTP. And we both agreed that okay, it could be this one but I wasn’t 100% convinced. But he literally begged me to remove the upper right molar. And literally in my notes patient begged me to remove an upper molar. I was like look, I’m not 100% sure it could be a lower tooth as well anyway, took the tooth out, patient said thank you, anyway comes in next day. Obviously he’s not out of pain yet. It was a bottom tooth. And we’re looking at you know, get my loupes on again. And look, actually you can see this microchip on the marginal ridge of a lower molar. And then actually, that’s where it was a crack with anyway and that removing that tooth and I could visualize the crack beautifully. Anyway, the patient was very understanding because he literally begged me to remove that tooth. But you know, we’ve all made a lot of us have made mistakes like that. So this is why it’s so important to make sure you get it right.

[Kreena]
Yeah, I mean, I think you highlight a very important point though that I mean, your consent process was exactly right. You know you with these sorts of teeth, even if I am pretty sure it’s that tooth with cracked teeth when they’re in that sort of state irreversible pulpitis, patient struggling to identify what tooth it’s coming from. I think it’s always important to, you know, say to them, Look, I you know, I’ll normally say I’m 80% sure, I’m 90% sure it’s coming from this one. However, your symptoms aren’t, you know, 100% we’ve got a couple of options. You either wait and let it localize more, which you know, sometimes some patients will say, Okay, do that and you warn them the negatives of doing that is that you can end up with a non restorable tooth because it can end up completely fracturing Or, you know, we treat this with you understanding that, you know, where it could be another tooth, which is exactly, you know how you handle that. And I think, you know, having that discussion with the patient is just really important because, you know, we can’t be 100% sure all the time, especially with these sorts of teeth.

[Jaz]
I think it’s important for the patient to sense that actually, one, it’s totally okay not to be sure and to be straight with the patient, rather than I think we’ll remove this one. And then when you’re wrong, everything happened. I like the way you know, I think, is this percentage sure, what do you want to do, then the patient could take some ownership as well of that. So that was just my little story. So now, you mentioned about the actual diagnosis being pulpitis, necrotic, that sort of stuff. So can you tell us about the crack teeth with associated what’s happening with the pulp because that’s essentially what it’s all about, you know, you can have a cracked tooth and correct me if I’m wrong, we can have a cracked tooth with no pulpitis at all. And that too, is just needs cuspal coverage, for example whereas a cracked tooth with the whole sequelae. So tell us a little bit about the sort of different types of diagnoses you can have with a cracked tooth.

[Kreena]
So, cracked tooth syndrome means that the tooth is vital. And so that’s not a diagnosis for an necrotic pulp. And so you have cracked tooth syndrome with a reversible pulpitis. And for that, obviously, patients have got maybe pain on biting that constant ache, pain that doesn’t last more than a couple of seconds, all the normal things, and then you’ve got cracked tooth syndrome with irreversible pulpitis. And for irreversible pulpitis, I tend to tell the patient you know, there’s a couple of ways of managing this, one is, you know, we could do root canal treatment, if you know, that would be, we take the pulp out and any you know, it’s also a problem as in terms of your symptoms, or we could handle it more conservatively and just put a cuspal coverage restoration on it. And, you know, most patients will say that’s what they want, because every patient wants the most conservative treatment possible. And there’s quite good evidence for this. So there’s two studies, one by [M sigma et al], in 2007. And I think it reached about 43 teeth with reversible pulpitis with a crack that was diagnosed and he put a direct composite onlay on them. And I think about 96% or 95% were asymptomatic at six years, which is fantastic results. You know, they’ve got reversible pulpitis they have an onlay on it, and everything, you know, everything gets fixed for them. But there was another study done in a similar year by Krell and Rivera and they said about 20% of teeth that had cracks and reversible pulipitis became symptomatic after a crown was done. So I think that that’s quite interesting actually because the first study did an onlay, composite onlay quite technique sensitive and the second study did crowns. So it I think the main difference in the results there was mainly because an onlay was done. So I think for teeth with reversible pulpitis and cracked teeth, we should be placing onlays and we should be hopefully you know doing things like immediate dentin sealing and making sure the temporary onlay we put on there is very good. So we’re not getting leakage because this will helps preserve the vitality of the pulp. However, you know if you are doing that I’ll always say to patients you know there is always a risk that the tooth can become necrotic or symptomatic. And in that case, we are going to have to strip this restoration off it, investigate the crack. See if it’s restorable, if it is, we’re going to put something else on there. So that conversation is very important because every procedure or any crack or caries you know, it’s all an insult to the pulp So we’ve got this tooth which is had a little bit of an insult because it’s got a crack in it, probably a restoration in it. And then we’re doing another insult by putting this onlay on it. And so you know that’s enough to sometimes just tip a tooth with reversible pulpitis over the edge. I think that consent process is very important.

[Jaz]
Well Kreena if money was no object, I would always in that situation where my diagnosis is cracked tooth syndrome, and we have a reversible pulpitis, if money was no object, I would go for an indirect onlay so be it gold or lithium disilicate, whatever, for example. However, it’s not nice when you’ve had to deal with a cracked tooth with reversible pulpitis and then after your intervention, it becomes irreversible pulpitis or becomes necrotic without the patient realizing and then eventually it’s an abscess, and then you’re drilling through your investment or the patient’s investment or the cusapl coverage what you’ve done so sometimes a good interim is like you said, a composite direct, I do a lot of these cuspal coverage just to see how it’s going to go and I consent the patient that look if it after a couple years, if it all is good. I think we really should for longevity reasons. Then progress to an indirect restoration.

[Kreena]
Yeah, I mean, 100% agree, I think some sort of temporary measure is always good. Only thing I don’t like about the direct composite onlays is I feel like the indirect ones are a little bit more stronger in the sense that when they were biting on the tooth got a bit more stability to hold the crack together. And so maybe I mean a short, slightly shorter term and how it goes and then put it indirect on there but sooner.

[Jaz]
I completely agree and something that Jason Smithson taught me he’s not that big of a fan of composite onlays to be honest with you, because he shows all these studies where the rigidity of ceramic is needed to really get that you know, cuspal coverage and actually prevent the fracture of a tooth. So the point well taken, so I think what we’re left off is right, where I sort of injected with the story was, you were talking about now reversable pulpitis part of the crack tooth syndrome.

[Kreena]
Yeah. So if the symptoms are going a bit further, and we were irreversible pulpitis now, I think that’s what you mentioned. Yeah. So from irreversible pulpitis now, we manage that very similar to if a tooth is necrotic, so those two are managed the same. So what I would do is I would then explain to the patient, on the outset that the treatment of these teeth is a lot more unpredictable, and both in the short term and in the long term. So short term, and we’re going to invest our treatment plan would be to investigate the crack. So what I would tend to do is if irreversible pulpitis, extirpate, and see how far that crack is going. Same if it’s necrotic, I would go into it and have a little look. At that point, we’ve got a lot more information on the extent of the crack. But in the short term, it’s unpredictable, because say we do treat these teeth, the crack may have extended further than what we can physically see. So we stand the best chance of seeing how far it’s extended with a microscope or with high magnification loupes. But even with those sort of devices, potentially there could be microcracks that have gone beyond the level that we can see. So short term treatment can be unpredictable. Although we try and minimize the unpredictability.

[Jaz]
This is what I mean with patients you know, cracked teeth are so complicated because of that, and you’re constantly sort of having to defend yourself, you’re constantly digging in front of the patient. This is why I hate cracked teeth so much.

[Kreena]
Do you know the way I find it very useful to show them a picture. So I’ve got one folder on my desktop with the cracked tooth in it. And I’ve got these this sort of sequential look at tooth all throughout me investigating the crack. And I find that patients don’t understand what I’m saying until I show them those pictures. And when I see them, it’s like a light goes on in their eye. And they’re like, ‘Oh, I understand why now you don’t know, you know why you can’t tell me because it you know, I can’t see where it goes.’ So you can show them the pictures and I find that very useful.

[Jaz]
Well, this might be a good point for me to show the people watching right now. And you have a cracked tooth which I opened up due to irreversible pulpitis and see what it looks like and then get your What do you see from your lens of the world? Can we do that?

[Kreena]
Yeah, of course.

[Jaz]
Fine. So share screen. So let’s make that bigger. So this is a lower right molar, diagnosis was irreversible pulpitis, raging lots of toothache and we opened it up, hyperemic pulp and what we’re looking at here is the distal marginal ridge, the crack extending into pretty much the pulp chamber. Now if I was to zoom in, I mean, this is very clear where my mouse is now the sort of higher part that’s very clearly crack. The bottom you can still see the crack line. So tell me, is this one for the bin Or not? Or do you need more information?

[Kreena]
And for me, this is probably one for the bin, not because if the extent of where the crack goes to, because I think that you know, it’s going into slightly into the black area, but it looks you know that doesn’t bother me as much. What does bother me is the width of the crack and the coronal aspect. So we can see the tooth is pretty much in two parts, you can almost see debris coming in, you know, pretty much at the level of the CEJ, I can see that crack is about, you know, point one or two millimeters wide, you got debris in there. So I think that is the reason that crack width is the problem for me, not the extent that it’s going to because, you know, when I look at cracks, as long as it’s not crossing the pulp floor or it’s extending, you know, very far into the canal orifice, usually even a millimeter into the canal orifice. I will treat that sort of tooth if the patient is keen for me to but the width of this crack is what I think is in some restorable.

[Jaz]
Well, that was a massive dilemma for me at the time, was really arming and arring and the patient. So I ended up doing a root filling for this tooth. But I take your point, I think now if I was look back at it, assessing the width is very reasonable say you shouldn’t treat that. I think it’s been three years now touch with all is good, but I don’t think this will be there in another five years personally. But it’s interesting how you say that. Yeah, I enjoy your sort of a look on it. And I learned something there to actually not just assess the depth, but also look at the width. And you see that you can see debris coming in. And that’s a red flag, I think.

[Kreena]
Yeah, I mean, to be honest, there isn’t much evidence when it comes to, you know, which teeth we should treat and what teeth we shouldn’t treat. There was actually I was going, I was going to do my own study on it, because I was treating a lot of these teeth, which, if you look at the previous papers, they were saying that they were unestorable you know, before, if you look at the evidence, it said that, if a crack is going, you know, to the level of the canal orifice, that’s for the bin and then you know, there’s very you know, high risk of failure when it comes to treating cracks. But if I did that, then so many of my patients would lose their tooth, and in my mouth, I would be treating these. So I started treating these sort of more severe cracks about five years ago, I had a great success with it. And there was a paper that came out last year actually, and which has shown very similar results, they treated quite extensive cracks and the cracks that extended just into the canal orifice. So if there was that five millimeters pocketing, you know, isolated pocketing associated with the cracks, and they had a great success rate, they had about 100% survival at two years, and 96% survival at four years. So I think actually, you know, as long as they were treated properly, which I’m sure we’re going to go on to the management. But as long as they were treated properly, the success rate was very, very good. And I think the main thing, I mean, as you treated with that one, it would be just telling the patient actually, you know, normally for me, when I’m treating these cases, I before I even started it, I won’t know if I can treat this or not until I open it up and investigate it. Once I have opened it up, I can give you a rough percentage of what I think so, for example, with that tooth, I would have said, you know, 50-50, or 40%, or whatever. And I would have given the represent digit that stage once I’d opened it up. And I think most patients are happy with that. And it’s that percentage that they then decide, I mean, I’ve treated a dentist a couple of years ago. And, you know, obviously he’s well informed. He, you know, very understands everything. And I said to him ‘Look, I think 50-50 for this, it was a you know, could see the crack, it was an isolated five millimeter pocket with the crack line.’ And I’ve chased it and it’s still in, you know, still in his mouth. So I think as long as we’ve properly consented patients, and spoken to them about the risks, you know, long term, short term, we should be treating them.

[Jaz]
I think just an interesting observation, I think with all realms of dentistry, the decisions that we make as clinicians, now if you’re someone who’s quite good at placing implants, and you come across a 50-50 crack, you’re probably gonna go towards the implant, because you know, everything, when you have a hammer, everything looks like a nail. Or if you have a really good endodontist beside you, or if you’re really good at endodontics, you probably have a crack at that, excuse the pun. So it’s just one of those things in life. So you’ve answered one of my next questions, which was how far into the orifice? You said about a millimeter even then, obviously, look, you know taking into account all the other factors as well.

[Kreena]
So if the crack extends across the pulp floor, for me, that’s a definite No, No.[Jaz] Sure. [Kreena] If there is an isolated pocket more than about five to six millimeters for me, that’s a no, no, although there have been studies that have shown good success rate with up to seven millimeter pocketing. [Jaz] Wow. [Kreena] But that pocket indicates that the crack has gone into the root, you know, it’s traveled into the root there. So five millimeters for me is a cut off. And if I do have any isolated pocket, that’s an immediate me telling the patient look short term, this is a lot more unpredictable. Yeah, and crack width is very important. So yeah, but those are the the factors that I look at.

[Jaz]
Brilliant. So the next question is, I think you’ve said the answer on this already, basically, about the evidence based for how long a root canal treatment can last, with patients with cracks. Do you want to mention anything else?

[Kreena]
And well, there was also a systematic review that was carried out last year, I’ve got the name here somewhere. Oliveira et al. It was a systematic review on all the evidence for cracks. And they said that there was an 88% survival at one year and an 82% success rate one year. The main significant factors that they found was it how many cracks the tooth had, or the tooth too tight, or the status of the pulps, if it was necrotic or reversible pulpitis. But it was more that if there was a perio pocket associated with it. So that was the main factor. But it was the Davis and Shariff study that I mentioned earlier than the one that I think is very, very good. And the main sort of outcomes of that study were that we place an intra canal barrier. So for example, with teeth that with cracks are the one that you showed, for example, what I would do is I would once I’ve obturated that tooth, I would put I’ve normally put composite below the level that I can see the crack extending, because we know that gp leaks. It’s not a very good material. It’s only for root canal fillings, it’s not good at preventing leakage. So one of the main outcomes is for this study was putting a microscope assisted into canal barrier. So sort of going, you know, far down the canal. And I think that makes a significant difference. And the other outcome was, what they said is they took the two paths of occlusion, and then they recommended a cuspal coverage restoration as soon as possible. And so when I treat these teeth, I tend to put a ortho band around the tooth, because dentist, so you don’t know, you know, when we’re treating difficult cracks, especially the bigger ones, you worry that I mean, I normally put a composite core in the tooth and leave it like that. But ones that are bigger, I find an ortho band really useful. And so I just take a very thin slice mesially, and distally which is what would you know, what the dentist would take when they put a cuspal coverage anyway, and I cement an ortho band with GIC. So as I pick a band that’s very going to be very tight fitting and bite stick for the ortho band so that they just bite on, it clips on and very easy to place, it doesn’t take very long. And that just holds that tooth stable until the cuspal coverage restoration is done. Because dentists get busy, you know, if they can’t, if you can’t get that patient back in your diary for another month or something like that, I think the band is really useful to help hold things together. But I think that’s another conversation for the patient, you know, before you start it, saying that, you know, you’re putting a big investment in this tooth, you’re gonna have a root canal treatment, and then for me, you’re going to have a cuspal coverage straightaway. And then we see how it goes, you know, if this doesn’t work, then it will have to still come out. You know, and if it does work, it might last you many years, but there is a risk long term, the crack can extend and the tooth may need to come out as well. And it’s a hard conversation to have witha the patient, you know, because, you know, it’s not easy. It does take time, you know, it’s to have that conversation. But I think it’s so important, because then they suddenly, you know, they understand you and them if we’re in the same boat, and you’re traveling, you know, this line together. And I find that the reviews, they come back and they say, you know, Kreena, it’s still there, it’s fine. You know, it’s we both celebrate together, you know,

[Jaz]
It’s undersell overdeliver, isn’t it? Really, the crux of all treatment conversations and consent it does a very important part of it, especially with cracks. And that’s why I hate it so much I don’t like like giving patients bad news all the time, like, Well, you know, it’s really dubious, and it’s just been a cracked tooth involved. I’m always like, super pessimistic.

[Kreena]
Yeah, me too. I mean, I give them the percentages, the rough percentages, and just then I sort of stand there. And it’s hard to be silent in that time while they decide. But I think the main thing is just be silent. Let them make the decision.

[Jaz]
Young dentists communication wise, is that never own the patient’s problem. Remember, the crack is in the patient’s tooth, not in your tooth. So make sure you dissociate yourself from that problem. The problem is out of your body, it’s in someone else’s mouth and their tooth specifically. So really give them as a professional, all the information you need to give and let them come up with the decision. don’t own it. Don’t get emotionally involved in that patient’s decision. I used to do that quite a bit. I think. Do you do it?

[Kreena]
Yeah, I’m very guilty of it, I think, you know, I’ll be thinking sometimes of a tooth that I should have treated or not treated, and I’m thinking about it at nighttime, you know, and it’s not a good thing to do. I think the more you practice that conversation and say, you know, you have it few times, and you get used to saying okay, this is your tooth, I’ve had the same problem. I mean, I normally tell them about my story, actually, because I was getting pain when eating raw [inaudible] I would get short, sharp pain when eating. And I was convinced it was my six. And it was my seven, I mean, the most common teeth to crack in the mouth are lower sevens first, then upper sixes then upper fours and five. So studies have shown that it was my lower seven, I was very close to getting a cuspal coverage, put on my number 6 tooth. And it was only you know, a little bit later, I had a raspberry seed and I asked someone, well, where is it and it was on my lower seven. And so I always tell them that story. And I find that patients quite like that if you tell them a story, you know, something that happened to you. They’re like, okay, she understands you know that this is a problem.

[Jaz]
Now, that’s a great way to communicate with your patients. So the last question I have, I think, was there any other points you want to raise about the consent conversation? Because one thing I want to say actually was, when I’m consenting patients for any treatment, not just root canal and crack, I always love to give them percentages, according to the evidence. I think that’s a very good thing to do, medical legally. So for example, if I’m doing a resin bonded bridge, I say, well, the study showed that if they last four years, they will then go on to last eight years or 10 years and 80% success rate at that point. I’d like to give them that sort of information. So what do you do in terms of consent? And do you give them like that sort of information that I’ve just described?

[Kreena]
Yeah, I mean, it’s difficult because there isn’t much evidence out there apart from this paper that I mentioned to you. And so the two papers, the Davis and Shariff one and the Oliveira one. Yeah, I mean, those are those are the two main papers, and they’ve got very good success rates. And so I don’t like to quote that, because obviously, it is difficult. So normally, what I will say is, if it’s a very minor crack, I will probably give them about 85%. That’s when I start. And if the crack is very extensive, so probably the one that you showed, that for me is, you know, 50-50, something like that. So it varies on how wide it is, if there is nice if there’s an isolated pocket, it instantly goes down for me to about 75%. Just because these things are unpredictable. And I think it’s you know, it’s a large investment for a patient. So it’s very important that that you like exactly how you said that you sort of undersell and overdeliver. And so yeah, those are the sort of percentages that I tend to give.

[Jaz]
I take your point, I think maybe you’re right, maybe with endodontics and cracked teeth, you don’t want to be quoting them as good as figures as in the studies because it sort of goes against the philosophy of undersell overdeliver and it’s just so variable and unpredictable and you know, that sort of stuff. So last question.

[Kreena]
Fantasctic variance actually, the success rate is over about 90%? I think. So

[Jaz]
I think because it’s you

[Kreena]
No but I do think I mean, even your patient, the one that you treated, you know, that’s fantastic result that you’ve got that patient three years out, is it three years?

[Jaz]
Three so far?

[Kreena]
Yeah, I mean, it’s fantastic result, you know, patients kept that tooth for three years. And for me in my mouth, that’s, you know, I’m definitely going for that sort of option. But I think sometimes for other patients, we you know, we’re so scared in this litigious world you know to treat something and then be told off you know, trying your best. So I think it’s, you have to be careful, but at the same time, like we want to, like do the best for our patients.

[Jaz]
Well, you’re completely right there, we’re less inclined to give it a go anymore, because of the climate we’re in. So the last question I have for you is, is there any evidence perhaps about? Well, some people say that when you have a crack, that you should chase the crack until you don’t see any crack anymore, whereas others are like, no, don’t chase the crack, because the theory is that the vibration of your bur is actually causing more microcracks. And that’s the camp I’m in actually. So I follow the principles of someone called Pasquale Venuti, who’s a fantastic general dentist in Italy, who lectures all over the world. I saw him in Sydney few years ago, and he was talking all that cracks and whatnot, and how he doesn’t chase crack. So I changed my practice based on that, but I don’t know, am I doing the right thing by not overzealously, chasing cracks?

[Kreena]
It’s difficult to say because again, there’s very little evidence on all of it. And if there is a vital tooth with reversible pulpitis, then I definitely wouldn’t be chasing any crack, I would be going straight from my cuspal coverage. And what I find is, when I do, I don’t chase them so that they disappear. But what I like to do is I quite like to open the tooth, so that I can probe directly at the level of where the crack is. So for example, if there is a proximal contact, we can’t probe properly, incidentally. So what I will tend to do is I’ll open the crack just enough, so I’ve removed the contact, so that I can probe directly where the edge of that crack is. And the reason I do that is I think it does change my percentage of success that I offer the patient because some cracks look, you know, not too bad, you open that there, suddenly, you’ve got an eight to nine millimeter pocket at that level, which would significantly change my management, whereas for others, you probe, you know, they’re a little bit wider initially, and you probe and there’s no pocket there. And it may be that I would then go and save that tooth. So I don’t agree with tracing it to get rid of the crack by any means. But I do like to know it for me, it impacts on my treatment. So I quite like to open it up just so I can probe that that contact there.

[Jaz]
That makes perfect sense because you’re opening your way essentially doing is you’re opening the contact, which is something that would have happened anyway because that tooth would have been needed a cuspal coverage restoration because that’s exactly what the crack is anyway.

[Kreena]
Yeah, potentially. I mean, it’s not ideal because if we remove the marginal ridge on a tooth, we do significantly lower the strength of that too. So if we could preserve it, it’s nicer I think it just I don’t get the information I need from doing that. So at the moment I am enlarging those ones so that I can probe and check. If the crack is very small. Then I don’t. So if I’ve opened that access and the crack is very hairline, it’s not got any staining coming through it you know sometimes you see cracks and you can just see that there is a crack there but it’s not got any black staining or anything like that, for those I won’t bother because I’m thinking you know it’s fairly minor anyway. The only time I do sort of check when I open them is when I worried at that tooth has become necrotic due to the crack. So if we look at most teeth that we treat, you know, if we take out an amalgam quite often we see minor crack lines, those I will never Chase, but if it’s a tooth that’s, you know, become necrotic or pulpitic because of the crack. That’s what I want to investigate on a bit further.

[Jaz]
Okay, brilliant. Well, the only thing that left a question with me now, based on what you said, was, I’m trying to think of my references now, but I think it’s either Ray & Trope 1985 or Aquilino, 2002, I think, or 1998. I’m trying think which year it was. But the whole thing about cuspal coverage after endodontics and how the loss of marginal ridge significantly weaken the tooth. Now, in those situations, typically in the absence of cracked tooth, if you’ve got the example occlusal caries in a molar, and that has led to let’s say, irreversible pulpitis or necrotic tooth, because the marginal ridge is around the entire 360 degrees a tooth is preserved for me in my book that it can often get away without a cuspal coverage restoration or just a well bonded composite can do the trick. Whereas if you have endodontics, and a marginal ridge involved, then I for me, my default is a onlay or you know a crown if necessary. But if you have a scenario where you sort of describe whereby you might have a cracked tooth with irreversible pulpitis, but there is no previous restoration, there’s no involvement of a marginal ridge. See, because it’s a cracked tooth, I will still be inclined to put a cuspal coverage restoration on it.

[Kreena]
Yeah, 100% I think if there is a crack in the tooth, that tooth definitely need cuspal coverage restoration, because I mean teeth when you’ve had endodontic treatment, they become weaker for a variety of reasons. One that you mentioned is the loss of tooth structure. And there’s a great study by Krell et al, which shows that if the marginal ridges removed, it reduces the strength of that tooth by about 63%. Whereas for small occlusal access it’s about 5%. Occlusal axis doesn’t contribute loads as long as we’ve kept it fairly minimal. But there’s other reasons why the tooth becomes problematic. One is proprioception. So you know, there’s pluses or minuses that proprioception, the pulp, isn’t there proprioception in the pulp, but there have been studies that have been done. [inaudible] actually, yeah, so there’s a really good study called them by And what they did was they put force on non vital teeth and vital teeth, and they found that non vital teeth took at least two times more occlusal load than vital teeth so that it shows that there probably is proprioceptive fibers in the pulp. Because non vital teeth you can put a lot more pressure on them without you knowing, you know.

[Jaz]
Are you sure you mean non vital? You mean vital? You can put more force in the- Yes. [Kreena] on non vital. [Jaz] Yeah, you can put- I see. So in the mouth, when there’s a non vital tooth it can take more force because there’s no proprioception to warn it that there’s this force. Okay, fine.

[Kreena]
Exactly. Yeah. And actually, they had to abandon that study because they kept breaking the non vital teeth. So that there’s obviously the medicaments and irrigations, we use. So sodium hypochlorite. All of that causes problems with the dentine and can can result in fracture there’s lots of reasons why endo itself weakens the tooth. So that in itself means that a cuspal coverage, restoration is a good idea. In terms of if there is just a smooth, small occlusal access, sometimes I will still recommend a cuspal coverage restoration on those patients depending on if they’re a parafunction patient or not. So if that patient has parafunction. And you know, all these factors when it with endo associated can cause problems in terms of how brittle the tooth is, and all those sorts of things. So, I will still sometimes in some cases recommend a cuspal coverage restoration even with a small occlusal access. But yeah, if there’s a crack definitely because we want to bring that tooth under compression rather than flexion. So the cuspal coverage restoration will mean that when we’re biting on the tooth, it’s under compression, rather than the two cusps flexing apart and being on deflection.

[Jaz]
Awesome. Well, I think that’s quite a comprehensive, I don’t know 40 minutes, whatever we’ve been done on crack teeth, anything else you want tell the listeners about cracked teeth in terms of something that might think is relevant to them.

[Kreena]
I mean, I think it’s only when it came to the diagnosis part. And the other few tips are transillumination is very good, staining can be very good in using something like methylene blue, and you can get dye that because sometimes helps you identify cracks. And sometimes if there’s a large restoration in the tooth, we can’t see cracks at all visually. So if you are very stuck on which tooth is causing the problem, you can just ask that, you know, say to the patient, look, I’m not sure we can remove the restoration in the one that’s more likely see if I can see a crack. If not, maybe, you know move on to another one. So those are just little tips on on diagnosis as well.

[Jaz]
I mean in as a GDP, there’s so many restorations I removed to reveal these nasty cracks. And at that point, you know, you pull out your camera, you take your photo out, you show the patient is all part of the consent process.

[Kreena]
Yeah, definitely.

[Jaz]
But it will. Kreena, it’s been amazing time has flown by speaking to you about cracks. And I think you’ve really given me some good definitive answers of the questions I wanted. And I’ve learned a few things about assessing the width, the jiggling of the tooth slooth. And also I do agree with you parafunctional patients, even if they’re only got a sort of a small access cavity, I am a bit more inclined towards cuspal coverage. So then loads of gems there. Thank you so much, Kreena.

[Kreena]
Thank you so much for having me. I really appreciate it.

[Jaz]
If you want to learn more, how can we sort of follow you and find out which other education that you’re involved with?

[Kreena]
I guess I post a lot of my cases for anyone that’s interested in and I post a lot of my cases on my Instagram, which is @kreenaspecialistendodontics. And I’m starting up an online endo course because I don’t think there is very much out there. And I constantly get asked about, you know, from people, different countries, even this country, because online learning is so important now, as with your podcasts, you know if you can learn from the comfort of your own home, it’s very nice. So I’m trying to, I’m launching my own online endo course, pretty soon. So yeah, watch that space.

Jaz’s Outro: So thanks again for listening all the way to the end. And within a couple of weeks, I imagine you can go on to Dentinal Tubules and answer the questions and get your enhanced CPD for that. Gosh, I hope by the time this episode’s out that lockdown is finished with some recording in the midst of lockdown. So I hope everyone is safe and well and their families are all good. And we’re going to hit back into practice with all guns blazing. And as always, thanks so much for listening. If you like the content, please subscribe, like and share with your Dental colleagues. And please, of course, leave me a five star rating on your podcast platform. That’s how my podcast actually grows. So please, that’s very important. I really appreciate it.