Fadiga cíclica de instrumentos mecanizados: uma revisão da literatura

Abstract

Introduction: The constant search for excellence in endodontics has given rise to new mechanized endodontic files, so that professionals have more confidence to perform procedures and reduce the inconvenience of cyclic fatigue. Since the introduction of nickel-titanium alloys in the market, mechanized instrumentation has been developed, which has brought several advantages such as high elasticity and resistance superior to stainless steel files. On the other hand, some have experienced such as the cyclic fatigue of these instruments when used in repeated cycles. The studies started to report the comparison of these files in relation to the different kinematics, conicities, manufacturers, sizes and alloys of their composition, in order to evaluate which takes the longest time until the instrument fractures, which results in greater resistance to cyclic fatigue. Objective: This work aims to compare different NiTi endodontic files with respect to resistance to cyclic fatigue, through a search in different databases, since there are many recent works in the literature. Materials and Method: 20 articles searched in different databases such as pubmed (Medline), scielo and google academic were selected. Results: supported divergences with the current literature, in which the rotational movement and reciprocal performance presents very similar resistance to cyclic fatigue. Conclusion: the heat treatment, shape and cross-section of the NiTi alloys are more relevant factors than the actual movement made by the files, requiring further studies on the influence on cyclic fatigue.