1 Akdeniz University, Antalya, Turkiye
Endodontic file fracture has traditionally been viewed as an undesirable event. However, recent evidence suggests that the incidence of fracture may be higher with rotary nickel-titanium (NiTi) files. Therefore, it is crucial for clinicians to be aware of the prevalence of file fracture and the underlying causes of this unfortunate occurrence. The removal of fractured files is technically challenging and time-consuming, making it essential to implement measures to prevent fracture whenever possible. Over the past decade, file manufacturers have introduced various modifications such as mechanical and heat processes to NiTi alloys to reduce the likelihood of file separation, though with varying degrees of success. The aim of this review is to explore the prevalence and causes of file fracture, and to assess the efficacy of the recommended prevention protocols. Furthermore, the review evaluates the effectiveness of alloy modifications in reducing the incidence of file fracture. The analysis reveals that much of the literature on file fracture is based on in vitro studies, which limits its clinical relevance. The reported incidence of NiTi file fracture is similar to that of stainless steel (SS) files; however, inconsistent methodologies make accurate comparison difficult. NiTi files are reported to fail primarily due to torsional overload and/or flexural fatigue, with fractures occurring most often in the apical third of the canal or due to improper use. Finally, factors such as operator skill, manufacturer modifications, and limiting file reuse have been shown to significantly reduce the incidence of fracture, highlighting the importance of a robust prevention strategy.
