A Serving of Meat and Potatoes

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This is not about insurance, 401k’s, or—believe it or not—about SafeSiders®. This isn’t even about investing in pharmaceutical companies or silver (thank the gods)! This article is just a meat-and-potatoes clinical case presentation. Now, of course, if it encourages my loyal following to refer an extra case or two, well then all the better, but for now just accept it as a case presentation that demonstrates where persistence pays off and that the easiest path may not be the quickest path.

It is important with any difficult case that you start out with the proper information. Of course it goes without mentioning that you must have the diagnostic tools to give you that road map to start your journey. A set of diagnostic radiographs is great, but when it comes to more bizarre issues the CBCT scanner is invaluable. A good radiograph, either traditional or digital, is great, but a 3D representation is even better. MB2s are a major reason for failure of maxillary molars, but a 2D radiograph gives you only part of the story. Just today, I had a patient with a purulent pocket over the MB root of #31, which recently had been endodontically treated, but in actuality the radiolucency and associated bone degeneration stemmed from #30, which was nonvital. On the CBCT scan I could see that the apex of #31 was intact! So, to make the proper diagnosis and render the proper treatment in this case, the CBCT scanner was clearly necessary. OK, I remember saying something about what this article wasn’t going to be, so on to the meat and potatoes.

A patient presented for a retreatment of a old failing root canal on tooth number 3. A fistula was present over the MB root (Figure 1). I did it as we do all our endodontics, and using an endodontic microscope I looked for an MB2 canal for quite some time without finding one. Well, having given it my best shot with a tad of frustration I may have knee-jerked to that common response we all have used at one time or another, “Obviously, Mr. Doe (that’s John Doe), the fourth canal, which we call the MB2, if it was even there to begin with, must be calcified. For if I was not able to find it under the scope, it’s not there (Figure 2).” I thus attributed the failure to a poorly done root canal.

Well, as Murphy’s Law of Dentistry goes, what can go wrong will go wrong, and so it did for my patient. He re-presented with a fistula traceable to the MB root. My head began to spin with self-doubt. How could I be so wrong? There must be something I missed! Perhaps the calcified canal routine was not valid?

I quickly ushered him off to our trusty CBCT scanner only to verify that indeed there was anatomy of the elusive MB2 to explore (Figure 3).

Figure 2

So, again, back to the microscope, ultrasonics and Munce burs to look for my nemesis. After a visit of exploration, I was able to find a secondary canal that joined the main MB canal. I cleaned and obturated it (Figure 4). Case closed, and a pat on the back! “See you in two weeks Mr. Doe” (that’s John Doe), and I was sure the fistula would be gone.

Alas, Murphy reared his ugly head again. The fistula was still there and there could now be only one alternative besides extraction . . . apicoectomy! So it shall be said, so it shall be scheduled. Mr. Doe was scheduled for an apicoectomy and on his appointment things just didn’t feel right. Throwing all caution to the winds after re-reviewing his CT scan again, I decided to re-explore the MB root. With the scope and assorted excavating instrumentation I actually found another catch on the pulpal floor which led me to the even more elusive MB3 canal with an independent apical opening (Figure 5). Impressive, hey? I instrumented and obturated and lo and behold, two weeks later the fistula had disappeared and Mr. Doe (that’s John Doe) felt great—not to mention very appreciative of my persistence.

Kase 2

A young lady presented with an RCT post, core, and crown that had failed and now presented with a symptomatic periapical radiolucency (Figure 6). I discussed the alternatives with her, and we chose an apicoectomy, for we did not want to disturb the coronal aspect of the tooth with a retreatment. So, I performed the surgery and sealed the root apex with an amalgam retrograde filling. DentoGen was placed in the defect. I felt good, and so did the patient (Figure 7). A week later, she came back for the suture removal, and, unfortunately, she was rejecting the graft material, and a fistula had formed.

Well, I changed her antibiotics, and—to make a long story short—we could not get the defect and drainage to resolve. So two choices presented themselves: re-apicoectomy or retreat with a post removal. With the patient’s full understanding of potential loss of the crown due to the procedure, access was achieved and the core material was carefully removed from the post head using fine diamonds and ultrasonics. The post was then vibrated loose and spun out of the tooth using a modified Flexi-Post® wrench trimmed down to fit through the access opening (Figure 8). I found the buccal gutta percha, which was inconsistently packed, and with very little effort was able to pass my instrumentation to the retrograde fill I had placed. I then identified the palatal fill in the same condition and was very surprised to find that I could pass an instrument to an apex and not my retrograde filling. “Harrumph.” I thought! Apparently the anatomical apex exited the palatal root on the palatal side away from my bevel and retrograde. Both canals were retreated and filled, the buccal to the retrograde filling and the palatal to its anatomical apex (Figure 9). The happy ending is that the fistula resolved and a new post will be placed with the patient keeping the existing crown (Figure 9A). Some may say that this was a lot of trouble to go through at great effort, but it was worth it to the patient—and to me as well.

The Moral of the Story

Most of the time, persistence and expertise pay off. Sometimes, the quickest form of treatment is not the correct choice. We all have our impossible cases, but knowing when to push on through treatment or refer accordingly is an integral part of our job for the patient’s benefit. See you all next issue.

April - June 2013

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Figure 9A