Tales from the Chamber
A Case of Separation Anxiety

Doug Kase
 
 

E HAVE ALL HEARD a white lie or two—or, for that matter, even told one or two—at some point in our busy lives. “The check is in the mail, I never got the message, I’ll start my diet on Monday,” and even, “That looks so good on you,” are a few good examples. But how about this one? Ever hear the one, “I have never broken an endodontic instrument in a tooth”? Well, show me the dentist who never separated an endodontic file in a tooth and I will show you a practitioner who just doesn’t do a lot of root canals.
    The breakage of an instrument is an unfortunate event that we all want to avoid, but if you do enough endo it is something that you will experience at one point in your career. As careful and experienced as one can be, there are some factors that might be unavoidable and put us at greater risk for instrument separation. Calcified canals, curved canals, dilacerated apices, and any combination of these are risk factors that increase the frequency of separation. In addition to the anatomical risks, there are built-in instrumentation system risks.
    You can reduce the risk of instrument breakage by using a system that you are comfortable with that minimizes certain stress factors. We all know the story of SafeSiders®, which reduce stress on instrumentation by staying within the limits of the mechanical and metallurgical properties of the instruments used, by using reciprocation rather than rotary motion, for example, thus eliminating cyclic fatigue. Regardless of what system one uses, it is important to know the system’s limitations and even the limits of your own comfort zone. With those limitations in mind, if instrumenting an extremely curved or calcified canal increases the insecurity of instrument separation, then this might be a case to refer to an endodontist. Certainly medico-legally referral might be a prudent decision for the benefit of the patient and the dentist. But please let me make one thing very clear: separating a file in a tooth is not malpractice as long as the patient has been informed of the act, prognosis, and possible future treatment that may be necessary due to the file separation and subsequent blockage of the canal.
    So what do we do if we separate an instrument? There are a few choices. One of the less ideal ones is to leave the separated instrument in place, obturate to the canal’s apical extent, and hope for the best. We watch the tooth for developing pathology and ultimately refer the patient for an apicoectomy or, at worst, extraction. The best choice is to remove the separated file from the canal or at least to try to bypass the segment and incorporate it in the subsequent obturation (Figures 1, 2, and 3). The thought of having a foreign object in the canal sometimes creates a fair amount of apprehension for the patient, so it is important to stress that the metal is no different from a prefabricated post and as long as it is within tooth structure and ultimately sealed around it is of no biological concern (Figures 4 and 5).
    Removal of a separated instrument can be quite a task. It requires the use of the endodontic surgical microscope and very fine ultrasonic tips. I would like to think that I wear a set of scrubs with a big “S” on the shirt, but there are situations in which I find that removal is not possible due to severe curvatures. In these situations, a bypass is the best you can do using .06 (pink) files and lots of RC-Prep. Placing a small bend at the tip of the file helps to find a guide path next to the separated segment. When a file is broken past the apex the necessity becomes greater for removal from a biological and psychological perspective for the patient (Figures 6–9). If not removable then an apicoectomy would be necessary to achieve an apical seal.
    In summary, instrument breakage or more delicately, separation—is a common risk in endodontics. If it happens, don’t ignore it. Explain it and then try to solve it. See you next issue!