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Endo tips    Better Endo    Endo abstracts    Endo discussions

MB2 : pulpal : canal : Bifurcation of MB2 - Courtesy ROOTS

The opinions and photographs within this web page are not ours. Authors have been
credited for the individual posts where they are -
From: sashi nallapati
Sent: Tuesday, October 03, 2006 8:04 AM
Subject: [roots] MB2

15 Irr pulpitis/ AAP.

If I havent believed in doing my best, and nothing but  my personal best,
i would not have found the MB2,

I gave up ALMOST twice to find it and treat it ...I am glad I didn't give took me
90 mts to find and treat the MB2 itself... the pictures explain the story...

for those cases, where the pulpal floor doesnt reveal the MB2, its important to inspect the
MB 1 canal for a sub chamber bifurcation for an MB2... the palatal could have been shaped better.
More power to Endodontics - Sashi Nallapati

Sashi, Another great example of passion, patience and persistence. Outstanding ! I have similar cases, on which I spend a whole session to find one canal. Very rewarding if you manage to achieve your goal. Of course I have also had the opposite, having to give it up eventually, after having chased a canal forever. This is one of the reasons that I always spend multiple visits on these kind of cases. I want to give myself a second chance, and start with a fresh eye the next time - Marga Sashi, This is absolutely first-rate stuff. What a service to the patient. This is really what itís all about isnít it? - Rod Sashi, Nice work (as usual.) I probably would have opened the access more both for better visualization and better light. Separate canals and separate POEs - makes it all the more important that you find em both. I do have a question about the "practicality" of treatment with regards to yours (and Rod's cases). How many of us are willing to spend 90 minutes finding and treating an MB2 just by itself - never mind the rest of the case? And if so (assuming you are charging "fee for service") would this be reflected in the fee? Or is a "Molar" just a molar no matter how long it takes? - Rob Kaufmann Rob, I don't tell them how much exactly it will cost them before tx. I only give them a range of fees . 20-25 % higher for the more difficult cases. if I feel that i had to spend more time than the routine then I charge the higher range.. In this case i charged 15% more than my routine fee for a molar. I feel, doing cases like these mean more to me than the fee I win some and lose some... I have had molars that I treated in an hour ... Sashi Nallapati Sashi, are these two canalled molars or do you count your time with sodium hypochlorite in the canals as a soak. I don't. Should I? I can't imagine doing a molar in an hour but you are a hell of a lot better than I can ever hope to be. - Guy Mostly 4 canals and more..I dont do hypo soaks,,I irrigate after every file atleast 1 ml per canal... at the end of the full cleaning and shaping i use EDTA, 2 or 3 mls per canal 3 mls of hypo again..per canal fit cones and pump them with the canals loaded with hypo.. If it is a necrotic case, i use ultrasonic agitation with a 15 file of naocl and EDTA and then i dry and obturate - Sashi Nallapati Rob, I certainly must agree. This kind of time-consuming treatment is not happening, nor is it likely to happen in the vast majority of offices. In fact Ė itís even worse than just a time/cost issue. There is a fundamental lack of understanding of biological objectives. - Rod Rod, Wonderfully said. In countries like mine and even worse in Rumania, India and elsewhere where you get 20$ per root canal all this is much harder. Two days ago I got to retreat a #16 because the patient was in pain. When I opened the tooth I was happy as I could see a brown line. I said c00l MB2 is here. Then I tried to find it, to no avail. I throughed the line until it disapeared, about 5 mm inside the root. Now I see nothing, no lines, no MB2. The patient, after 120 minutes of work was exhausted, and so was I. The truth is, I booked her for another 90 minutes next time. I hope her symptoms go away with the Ca(OH)2. If I don't find those MB2, they can come and haunt me at the followups :-( Oh and my income from this treatment is just 200$ (before the taxes that are more then twice USA). I had a nice chat with another endo specialist in my area. He said he doesn't think MB2 matters that much. If this comes from the mouth of a specialist how can we expect a GP look for those ? Many gp's use just saline to irrigate, having many excuses. Imagine my surprise to hear a lecture from another specialist saying he uses saline as well ! (not exlusively, but never the less) Thomas P.S Last time I had a MB2 hard as this I throughed it for 2 hours, then found it, treated it. I was happy to see it had a seperate POE. I hope this tooth will have the same end. Found one of those yesterday on a patient referred to me for the endo. I kept noticing my file in the MB canal going in opposite directions on measurement. Finally took a radiograph and there the two canals were. Then I could see the divergence in the scope. They merge about 2 mm from the apex. Don't you think these occur in very small MB roots? Guy Rod, here's one that I just completed. It was tough because the patient is a moderately mentally challenged 40 yo woman. This was a two and a half hour appt and I searched for the MB2 for at least 45 to 50 minutes. I admit part of that searching was while sodium hypochlorite was in the other three canals. The radiographs are a little blurred because she gags terribly with film. She tolerated the dam so I don't know what it is about the film. We would have to give her breaks from the damn so it we had to place and remove temp restorations three times. It was straight forward except for my inability to find the MB2 here. This is the first one in a long time I have not been to find. Ultrasonic and Munce burs didn't locate it although I'm sure it is there from the root shape. Time will tell. My point is that I did essentially everything you mentioned below except search for the MB2 for 90 minutes. Some of us are trying and having a little success - Guy

Hi Guy, Wow! Thatís a lot of time you put into this one. Itís good to know there are GPs out there willing to do that. Kudos. I agree with you that this one clearly has an MB2 from the radiographs, and I believe it should jump out once it is uncovered. The MB2 canal here is a very good size (red arrow) and the double PDL here (green) adds more proof of a very certain MB2 system

A file will drop into this one easily. The only question is, where is the orifice? Your mesial angled film shows a very prominent ML bulge (yellow), which means the MB2 is going to be very mesial to the MB1. It will NOT be in a direct line between the MB1 and the P canals. I can also tell by your films that you have not uncovered dentin searching in this area. You need to start unroofing dentin carefully toward the mesial wall. What are you using for magnification? Hereís what Iím talking about. The MB2 orifice in this type of anatomy is not evident with the dentin shelf overlying the canal orifice. The canal will likely be way out in the area of the green dot or further.

I see you have Munce burs. I love the Munce burs. In fact, I can easily say they are the single best advancement in my technical practice in the last few years. I virtually have not used my Buc U/S tips for unroofing anatomy since I started using these last May when John got them on the market. (Thanks John) But, like U/S, they require magnification to be effective. In fact they can be downright dangerous without it. I usually begin uncovering these starting at the MB1 orifice, but to illustrate in this case I worked from the center out toward the mesial wall. #1 Munce discovery bur. Look for the white dot. Have the assistant blow the dentin chips away with the Stropko while you work.

This is an 8c file, and I just poked it in for the picture. The orifice is not completely unroofed and this canal is not ready to negotiate yet. It takes a sharp, near 90 degree mesial to apical turn at this point. You need to keep unroofing these before any instrumentation.

The next pic shows it fully uncovered and straight-lined. Look how much further in it is. I left the remaining dentin shelf for the picture to show how far mesial I actually had to go on this one. Now itís ready for files and apical work. The rest of the dentin shelf needs to be uncovered and troughed between MB1 and MB2. I hate to say it Guy, but Iíd get her back in. Forget about the lost hour. If you uncover mesially like this case, Iíll bet you find it in 5 minutes. - Rod Thanks Rod. I use a Seiller scope for magnification. It is only a three step up to 12x but that is sufficient for me. Rod, this kind of assistance is what Roots should be about. When I graduated from dental school in 1969, a fourth canal in an upper first was an anomaly. Now it is always there and I find 90% of them. I'm doing a lot of retreats now...mine and for other people. That is the ultimate learning experience. It is absolutely amazing to find the number of second canals on the distal of lower firsts that people simply didn't look for. This is a fantastic tremendous help. I'm printing this out and saving it. I'll get her back in and work on the mesial wall. Heck, if I perf it there it can easily be repaired. I have learned that many of these are essentially under the mesial margin ridge. I always cover my access with purple flowable so getting back to my final point will be easy. As I said, I find 90% of them now. I'm doing a pretty good job down here in the Swamp where we have clean air and a lot of space. Respectfully, Guy Guy, It sure looks like an mb2 should be there. Sometimes the mb2 originates from the palatal orifice. Did you see a white line? If so, that needs to be troughed apically. Sometimes the orifice to the mb2 is 2-3mm's apical to the level of the chamber floor - Mark Went to the palatal and there was no white line. There was one from the MB, which was a huge canal. I chased the white line until it disappears and troughed mesially until she got pink. Came on a straight line from the palatal towards the MB with the Munce bur DEEP apically both places and could not find it. Stayed away from the furcation. As you can see 15 is a goner and I didn't want to perf this one. She has a tough life. Another one of my discount patients but she is a sweetheart. She tries so damn hard to cooperate and does a good job. This was almost three hours in the chair for a challenged person...with a dam most of the time. I hope this is one that merges - Guy If it fails, bring her down to my place. I'd be glad to take a n/c look and see if you missed anything. You can watch me in the assistant scope. It might be a valuable opportunity for you to learn another spot these canals hide in. Of course, I might not find it either - Mark Guy, Wouldn't this be a great opportunity for a second visit with fresh eyes and a fresh patient? I find many things at the second visit I missed at the first. Often straight in there for some strange reason. I still can't get my head round taking the dam off mid treatment for a rest. Why not take it off for a rest for a few weeks with some calcium hydroxide in place? Allows you to make it a shorter visit, and be able to run on time as well? That way you are both happy. With the correct explanation patients don't mind coming back. I do it all the time with 2 - 3 hours traveling involved. - Bill She's been in Ca(OH)2 for six weeks. Actually this was a second look but I got more aggressive with the Munce. I didn't take the dam off. She did. A severe heart defect prevents any sedation. I treat a lot of these patients, Bill, because no one else has the patience to try. This one has been in the hands of an endodontist once and released because she pulled the dam off or pushed it off with her tongue. I try to give everyone a fighting chance. I know you guys say pull the tooth if you can't keep the dam on for the tx. Well, I'm old enough to remember when 90% of the endo was done without a dam. We have moved from using the dam to prevent aspiration to preventing contamination. And I agree with both but I'm not so damn set in my ways that I will extract a tooth if I can't use a dam. Sometimes you simply have to have an isolation plan. The canals were always full of bleach and we had the IRM on go the entire time. She was a difficult case but one that I had to treat. This was a half fee case. She just lost her beloved father six months ago to a ravaging rare form of cancer that started in the muscles of his buttocks and base of his spine. It was a horrible six year battle and death. The have little money and she struggles so damn hard to sit in that chair that I get emotional with her. She also tries so hard to do what I want and breaks down every time she pulls the dam off. This was a two appt case and I'm rambling. I'm a bit emotional recently. Thanks, Guy Rod, That is really amazing stuff. Once the orifice was located you mentioned "The orifice is not completely unroofed and this canal is not ready to negotiate yet. It takes a sharp, near 90 degree mesial to apical turn at this point. You need to keep unroofing these before any instrumentation." What do you use to completely unroof, uncover and straight-line that orifice and make it ready to negotiate. Many times I encounter these 90 degree almost semi-circular mesiodistal curves on MB2 and most of the time I end up ledging and it becomes either impossible to proceed to patency or I near perforation, now that you mentioned it I think that happens because I do not do enough unroofing to straight-line that 90 degree turn. So can you please go over how you do it to overcome that sharp curve and how much margin do you have when you do that since that canal is already emerging from a very mesial point and one would be cautious of a mesial perf or at least overthining the mesial wall? - Mohammed Elseed Mohammed, I used to use the Buc ultrasonic tips for unroofing. I like them, but now I use Munce burs for the entire unroofing. Under the scope, you can sweep them very accurately and remove exactly the amount of dentin you choose. Use them in a dry chamber. They create a larger dentin debris which is easily blown out of the way by my assistant using a Stropko tip while I work so I am able to see exactly what I am uncovering under the scope. The fine powder or dentin dust that the U/S makes cannot be cleared as easily. It often sticks to and occludes what I am trying to uncover, especially if there is any moisture. When looking for MB2ís most people go deeper along a line toward the P canal. Big mistake. You can perf furcally. Others extend their access mesially, but still donít uncover the shelf (see stripes). Here is where you could perf mesially. You donít randomly search mesially; you must stick the canal or fin before you extend mesially and then follow the canal as you unroof. Others manage to find the entrance to to the MB2 early, but find it can be nearly impossible to negotiate because of the severe initial curvature. If you try to enter most MB2s to soon, you donít have proper straight-line access and will get stuck in the first few mm. An early ledge or block causes most to give up at that point and say itís calcified. It is still recoverable at this point, just more difficult. Far better to get a direct line access before files are forced into the sharp initial curvature.

Once youíve located the MB2 orifice under the shelf, continue gently sweeping the shelf away mesially and slightly deeper Donít drill straight down at the canal because youíll lose it and be heading for the furcation. You want the outer (mesial) aspect only. Once it starts diving apically, take an Axxess #2 or a tapered diamond with no cutting tip and extend your wall to give you better straight-line access. Then work your small files with RC prep in the coronal to get a feel for the canal. If you need to unroof more do it, otherwise do some SS negotiation and crown down with GGís to open up the rest of the coronal third. I took a few video captures under my scope today of an upper first molar I was working on. Pic 1. Initial access and bulk coronal GG work in MB1 and DB. This is where the NEDs get out the paper points and gutta percha. :-))) Pic 2 - Began uncovering and removing schmutz with the Munce burs under the scope. Got an explorer stick in the MB2 and then I stuck a file in (for the picture only). It hit a wall in the first 3 mm. Pic 3 - MB2 unroofed and straight-lined. Canal ready to begin apical discovery. (access is not refined yet) - Rod

Nice description Rod. Ever since discovering Munce's burs, I too have moved away from using Ultrasonics for troughing in situations like this. I find Munce's burs are not only waaaaaaay cheaper but they are much more efficient. They don't generate as much dust as I did with a dry US ( which sometimes obscures the MB2 groove) and they don't have to be used with H20 - which geratly improves visibility. I still use US for smoothing, prepping fins and isthmuses etc, But nothing beats a small round bur placed in the right location, at the right angle - to find MB2. By that I mean that you have to be sure NOT to penetrate axially when looking for MB2. ( See my addendum to)your pciture) As you stated, this can result in a perf. The bur is most often tilted far to the distal upon appraoch.(45 degrees?) This is more easily done when the D proximal box or marginal ridge are gone. I am convinced that most people miss MB2 because they don't "unlip" properly. Most of them never even knew it was there. - Rob Kaufmann

ditto. sometimes I think it would be nice to have an intermediate length Munce disco bur---just a couple mm shorter ---but usually the length is fine because of the angulation and depth it's working, creating the nice visibility. i was thinking of this today as my disco bur was dancing down a white line - KendelG Kendel, You can easily make them shorter if you want. Just cut the shank back with a 557. Making them longer is a bit more of a problem. - Rod Are you using friction grip??? Mine are latch, and you cannot shorten either end. I guess you could cut it in the middle but - Gary Doh!! I was thinking about my HS long shank round burs. Sorry - Rod Hi Rod I thought you were joking cos if you cut the end off the discovery bur it will be shorter, but have no cutting tip. Unless you can cut a new tip on the end of the shank under the microscope ? Regards - John Hey John, Sure! Cut a new tip under the scope. Now that would take a steady hand. :-))) Actually, John Munce and I both lectured at LLU in February and at that time he was custom making his discovery burs by taking surgical length slow speed round burs and custom milling them chairside to a thinner shank diameter. Heíd spin the SS bur in one handpiece while lathing it down with the HS handpiece. Pretty clever. I tried to do a few when I got back to the office. Letís just say Iím glad I can now buy them already made. Anyway, I frequently use surgical length HS round burs and occasionally custom shorten them by reducing the shank length. I was thinking of this in response to Kendelís comment forgetting that the Discoveries are a SS latch shank. Brain lapse could have been the Merlot. Who knows? Another chairside modification I occasionally make is to cut half the tip off of a GG #2 or 3 to make them end cutting. A bit dangerous, but they are excellent for removing cement at the bottom of a post hole after post removal, and other areas where deep cutting is needed. - Rod Rod: From your picture and discussion you are trying to locate all canals, including mb2s db2s and the like right from the jump? If you are not immediately successful, do you ever start your coronal and middle prep of the main canals with the chamber flooded, let the hypochlorite do its thing for a bit, and then come back to it? - Gary Gary, Actually, I always like to open into and negotiate the three main canals first before searching out MB2s and DB2s. It gives me a good reference point to begin uncovering and troughing. In these pics, the MB1, DB and P are fully shaped and soaking before I even begin removing the shelf. - Rod Gary, Sorry here, I was referring to the first pics (to Guy) that are fully shaped and soaking. The pics from yesterday (to Mohammed) are just opened with GGs and initially negotiated. As I started cleaning out the junk from the floor, the MB2 stuck so I unroofed and preflared it also. Then I refined the access and fully shaped all the canals - Rod Thatís the way I normally do it, but I thought Iíd ask. Iíll take a quick look around with the scope after access form is completed, but if it doesnít jump out at me, I donít even bother until I have a road map provided by the main canals, and potential opening of the mb2 et al by hypochlorite soaking throughout the procedure. - Gary

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