Tales from the Chamber
Mother Nature Is a Lousy Endodontist!

Doug Kase
 
 

ELCOME BACK, my loyal readers. I hope your summer has been a hot, sunny, and dry one, quite the opposite of its June beginning. Before I get into the bread-and-butter or meat-and-potatoes of this Tale, I want to digress and write one more time about the subject matter of my last article. To refresh your memories, I wrote about the quality of our endodontic product versus what experts consider the standard of care when dealing with a malpractice action. I am seeing malpractice actions more and more in the cases in which I provide expert review on behalf of my colleagues. Often the action centers on the idea that the old-fashioned .02 tapered endodontic fill might not stand up to the scrutiny of the plaintiff’s expert and attorney when .06 to .08 continuously tapered obturation are the current standard of care. Couple that idea with a thin wispy obturation, and the situation really becomes a no-win one for the defense. With the addition of the microscope to find calcified or submerged canals, in the eyes of the court and your malpractice company, the standard of care is to refer to a specialist if the case is too complicated. Missing canals might not be deemed malpractice if the canals are truly calcified to the point where extensive excavation would jeopardize the prognosis of the tooth, but if the canals are accessible with the microscope then a referral to a specialist would have been appropriate. My summary point is that we teach endodontics in a simplified, predictable method that minimizes instrument separation and all the stresses of bells and whistles rotary techniques. If you are going to do the endo, we want you to learn how to get the results that work and are clearly defendable in this screwed-up litigious world in which we practice.
    Okay, so here is the case! A patient walked into my office and said “Doc, it hurts when I push under my nose.” I said, “So don’t push under your nose!” Actually, that was not too far from the truth.
    A patient presented with pain to palpation under her left nostril over the apex of tooth #9. She told me a history of trauma to her incisor at an earlier age. A radiograph confirmed a radiolucency associated with the apex and, to my dismay, a calcified canal with only a hairline hint of some remaining patency (Figure 1). I discussed with the patient the options and the risks associated with attempting the endodontics or proceeding directly to apicoectomy. I felt strongly that the conventional endodontic treatment solution was the better option considering that the microscope and ultrasonic tips were at my disposal. Anesthesia was administered, and access was started. Lo and behold, an explorer catch was found (Figure 2). I threaded an .06 into the catch with a wristwatch-winding motion, and it was sticking, but not moving apically. I placed the reciprocating handpiece and started the process and I did get apical advancement (Figure 3). However, this radiograph did show that the instrument was not following the center of the tooth. It was time to pull back and regroup.
    Under the microscope, the hunt for a calcified canal can run the spectrum from a quick discovery, a piece of cake, to an hour of hard work and sore eyes. First of all, have a couple of brand-new explorers at the ready. A dull or slightly bent tip will get you nowhere fast! I use ultrasonic file tips, such as a CPR-3 or CPR-4, under low power to slowly excavate the landmark I see under the scope. When you are using transillumination, you will find that the calcified canal appears as a dark spot. When you are using the scope illumination under magnification, the canal will appear as a spot whiter than the surrounding dentin, almost chalky in appearance.
    So, back to the case! I re-excavated a little toward the buccal, following the white spot and again caught a catch with a new explorer. Speaking of the explorer, sometimes as you excavate deeper into a root beyond the length of the explorer you may find that you have to do some instrument remodeling. I straighten out and re-bend the explorer at a longer length so that I can reach the depth of my excavation. I threaded an .06 instrument into the catch, and with a little wristwatch-winding hand motion the instrument progressed apically beyond the length of the original path with a bit more ease.
    At this point, it was time for a confirmation radiograph. A dead-on shot (Figure 4) and a mesial angulation (Figure 5) showed that the instrument was dead-on and following the canal. These results show the importance of taking multiple films from multiple angles. By the way, the apex locator consistently showed that I was in the canal! I advanced my instrument to the apex and did the complete instrumentation under reciprocation from an .06 to achieving my final taper with the brown SafeSiders® # 25 .08. The canal was obturated using EZ-Fill Express® sealer and a single cone of gutta percha (Figure 6).
    Even though the procedure had its risks, the success of a slow and methodical treatment made the attempt well worth the effort.