Endodontic instrument fracture constitutes one of the complications of endodontic treatment, as their removal is difficult and time-consuming, and requires the use of specialist armamentarium. Even though its incidence does not seem high, it still poses a significant risk and is related with much worse prognosis in cases in which apical pathology is present The presence of the instrument itself does not lead a failure in treatment in each cases, but if the fragment blocks proper chemomechanical preparation of the canal, the microbiological aim of the treatment cannot be achieved, and complications may ensue. A variety of methods have been described for removing the fractured fragments, such as ultrasonic devices, tube-shaped devices, or lasers. If none of the approaches is feasible, the clinician may decide to perform endodontic surgery, e.g. apicoectomy or root amputation, or choose a watchful waiting approach. The following paper discusses a few clinical cases in which different therapeutic methods, which seemed most appropriate in a given clinical situation, were used.

Key words: endodontics, root canal preparation — adverse effects, dental instruments.