Dr JT (Koos) Marais

Removal of fractured root canal instruments from the confines of a root canal is technically one of the most difficult procedures in the entire array of medical and dental treatment modalities. It is no surprise that the success rate of removal is not very high. The instruments are just too small, and the canals too constricted, and difficult to access, to allow easy manipulation of these tiny fragments, often times smaller than two or three millimeters.

 Is it always necessary to remove these instruments? Fortunately the majority of cases can be left untreated, because the teeth remain symptom free, despite the presence of the offending fragment. Every now and then, however a case rears its ugly head where action must be taken.

A patient, a 25 year old female, was referred for the retreatment of a root canal of a first lower right molar (46), complicated by the presence of a fractured root canal instrument in one of the mesial canals. (Figure 1)  Figure 1

The patient was experiencing constant pain from this tooth since the original treatment a few weeks previously. Careful studying of the radiograph would seem to indicate a radiolucency around the distal root's apex, but the fractured instrument was clearly visible in one of the mesial canals.

One can argue that the pathology of the pain was more than likely due to the distal canal being treated perhaps inefficiently, since no radiolucency was visible peri-apically to the mesial root. That is if one was that way inclined, and did not have the expertise and technology to perform this very demanding task. Perhaps one would even be successful by retreating the distal canal only. But, at the same time it could be viewed as extremely foolish not to attempt to remove the instrument, if and when one had the opportunity. It is all a matter of opinion, which is strongly influenced by the operator's perception of his or her capabilities.

I anaesthetised the tooth, isolated it with a rubber dam, and accessed the pulpal chamber. I then removed the GP using Gates Glidden burs and visually, with the aid of the endodontic microscope, confirmed the presence of the fractured instrument in the mesio-lingual canal. I then removed the fragment with the modified U-File tip on the ultrasonic device. The removal took approximately 45 minutes of painstaking work, demanding utmost concentration, all the work being done under the microscope.

A radiograph (Figure 2) confirmed the complete removal of the fractured instrument

                              . Figure 2

I then proceeded to complete the retreatment of all three canals and the patient is expected to make a complete recovery. The final result of treatment is shown in Figure 3.

                       Figure 3

Was it all necessary? No one will ever know. Life is not that simple. From the patient's perspective it would appear to be an open and shut case, but personally I think that there would have been some chance that the symptoms would have resolved by the retreatment of the distal canal alone, a very easy procedure, from my perspective. But then again, I could have been wrong, and would have subjected the patient to further trauma and treatment.

As things turned out, the problem was resolved. All that remains is to reflect and to remind ourselves of the inherent dangers of the procedures we use, every minute of every working day of our lives.