Tales from the Chamber
The “Kase” of the Chronic Complainer

Doug Kase
 
 

ID YOU EVER have one of those patients who, no matter how hard you tried or how much good you did, just kept coming back and complaining? Even when you do everything right in endodontics there is always the situation in which a patient continuously has complaints about the tooth on which you just did a textbook root canal therapy. The patient’s complaints may include not being able to bite down on the tooth as he can with all the other teeth in his mouth, or that the tooth hurts when she hits it with her tooth brush. The pain is usually vague or intermittent; it never happens when the patient is sitting in your chair; and it is also impossible to reproduce. A patient may even report that the perfect root canal therapy you did is still sensitive to temperature! Impossible . . . right? You start to think back on the treatment and ask yourself, “Were the four canals that I located and cleaned all of them? Could it be a periodontal problem?” So you probe the crown margins and sulcus in hopes of finding an inflamed pocket, which of course would explain the chewing symptoms. Then you tell yourself that it must be a fracture because what else could it be and why retreat it because it was a damn good root canal job. Or maybe an adjacent tooth might be causing the temperature sensitivity. All these things are reasonable explanations for the complaints of a patient who chronically complains about a tooth that underwent endodontics.
    So if you rule out the obvious problems—such as periodontic pathology—and eliminate the probability of root fracture, the first line of offense might be to place the patient on a regimen of antibiotics to see if you can rule out an infectious pathology due to a failing root canal. Ruling that out would not explain away a temperature complaint, but it might indicate that you might just be unlucky enough to have your beautiful result fall into the extremely low failure rate for endodontics; in that case a retreatment would indicated. The question remaining is why do root canals fail? The explanation itself could be a long chapter in an endodontic text, but to give you some quick reasons is easy. An inadequate apical seal or tissue left in the canal due to under-instrumentation can lead to breakdown and bacterial growth at the apex. Apical transportation or perforations are also sources of continued discomfort. Even gutta percha overfills due to improper measurement control or over-instrumentation can be culprits. And, of course, last but not least, is the old lateral canal or missed extra canal, for this can certainly happen to the best of us. So, listen to your patient, and if in doubt do a retreatment, because there is nothing to lose except a little time and there is a world of good will to gain.
    So here is the case: a nice gentleman presented for endodontic treatment on tooth # 18 due to symptoms of a pulpitis (Figure 1). Easy . . . right? Endodontics was initiated; three canals were identified, instrumented, and subsequently obturated using the EZ-Fill® technique (Figure 2). The patient was asymptomatic for the moment, but he returned after about a month with renewed symptoms of chewing discomfort, heat sensitivity, and slight percussive reaction. After exhausting all the diagnostics, I decided to follow the reasoning I described above and retreat the case to make sure that it had been instrumented and sealed properly. I removed the old filling material and reconfirmed measurement by apex locator and radiograph (Figure 3). I still found only three canals, but I re-instrumented and re-obturated them (Figure 4). Over the next two months, the patient reported that the tooth was really never quiet and the symptoms were now getting a little worse, particularly the pain response to heat. Impossible . . . right? I had him back for a recall film (Figure 5), and there was no radiographic pathology that I could see. I placed a well-sealed rubber dam around tooth # 18 and flooded it with hot water; I was able to verify that indeed this tooth was heat-responsive. Nonetheless, this was becoming a challenge from which I could not back down. Perhaps there was another distal canal that I had missed; that would certainly explain the heat sensitivity. So onward and inward I went. After cutting on the dotted line to regain access, I fully intended to remove the distal fill. However, before I did I decided to take a crack at the isthmus between the MB and ML canal in hopes of finding a middle mesial canal, which would explain everything. Lo and behold, after a little digging with a fine ultrasonic CPR-5d file, I found a catch, which opened to an independent canal that ultimately did not join either the MB or ML as many middle mesials do (Figure 6). Instead of re-treating the other canals, which could lead to greater complications, I directed my efforts to the unfilled canal, which I cleaned and obturated successfully (Figure 7). The patient is now asymptomatic and can enjoy a good cup of coffee without thinking of me. Another happy ending. It is important to keep the elusive middle mesial possibility in mind when endodontically treating lower molars.