Broken instruments
Fracture of endodontic instruments during root canal treatment is an unpleasant complication that every dentist/endodontist has to deal with. The most common way is to remove it. Of course, this depends on many circumstances: whether the instrument broke during vital extirpation (not a heavily infected canal) or in an infected canal, whether the instrument broke in the coronal, middle or apical third. Removing a broken file at the cost of weakening the cervical dentin or perforating the root is definitely not the way to go.
We must always remember that the instrument itself does not cause inflammation, so it may remain in an uninfected canal despite unsuccessful removal or bypass. We often see teeth with fractured instruments that were treated many years ago and have no clinical or radiographic evidence of periapical inflammation.
In a case like ours, the broken file has to be removed or completely bypassed. The patient came to the dentist already with pain. During the RCT, the instrument broke and completely blocked effective disinfection of the infected apex. Antibiotics were prescribed and the patient was referred to us.
Using a sequence of hand and rotary instruments, we performed a full bypass:
C+ file ISO 008, 010.
Hyflex EDM 10/05 at 1000rpm.
Bypassing was further continued using ProTaper S1 → F3 in reciprocating motion.
In this way, a fully functional bypass was achieved.
Subsequently, ultrasonic activation was performed using an ultrasonic tip in short intervals.
In this particular case, the fragment itself could neither be visualized nor removed. However, since it did not obstruct apical disinfection, the decision was made to leave it in situ.
During ultrasonic activation of the disinfecting solution, the fragment was unintentionally displaced beyond the apex.
If a proper disinfection protocol is followed, there is no reason for concern nor for indicating surgical intervention. In combination with extruded calcium silicate cement, the inflammatory process is expected to resolve uneventfully.
