This study aimed to relate the file fragment length and location in the root canal to the retrieval chances, the clinical time required and the occurrence of secondary fractures.
Sixty clinical cases of fractured instruments were included in this study. They were classified according to the instrument length and the location of the root canal. In each group, the success rate in the instrument retrieval, the clinical time required and the occurrence of secondary fractures were evaluated. The collected data were analyzed using the Kruskal-Wallis test on the basis of a 0.05 significance level.
The fragment length showed no significant influence on the assessed variables (
In accordance with the findings of this study, the fractured fragment length did not influence any of the variables assessed, but it is suggested to focus on the fragment location inside the root canal to decide the retrieval of a fractured instrument.
During root canal preparation procedures, the potential for instrument breakage is always present. When instrument breakage occurs, it leads to anxiety of the clinician and as well as a metallic obstruction of the canal which hinders further cleaning and shaping. Separated instruments must always be attempted for retrieval and if retrieval is not possible bypass should be tried. With the increased use of nickel-titanium (NiTi) instruments the incidence of separated instruments has increased. A considerable amount of research has been done to understand the various factors related to the fracture of NiTi instruments to minimize its occurrence. This paper presents a review of the literature regarding the fracture of NiTi instruments and also describes a case report showing the use of a modified 18-guage needle and cyanoacrylate glue to retrieve a separated NiTi instrument from the mesiolingual canal of a mandibular first molar.