Radiographic evaluation of root canals’ morphologic alterations prepared by the Hero 642 rotary system and nickel-titanium handly files

Abstract

The purpose of this study was to evaluate by means of superposi- tion of preoperative and postope- rative radiographs, the occurrence of morphologic alterations in the apical third of root canals prepa- red by Hero 642 rotary system (MicroMega, Besaçon, France) and nickel-titanium (Ni Ti) manual fi- les NitiFlex™ (Dentsply/Maillefer, Ballaigues, Swiss). In this research was used 40 human mandibular molars, with the rhizogenesis pro- cess concluded, obtained from the Human Teeth Bank, of the Post- graduation Course in Dentistry at the Health Science Center of Uni- versidade Federal de Pernambuco, with the objective of comparing the morphologic alterations, in the api- cal third, produced by the root ca- nal preparation, in which the final apical instrument was one with the diameter D0 equivalent to 0.25mm. The radiographic images were analyzed by three independent ob- servers, endodontists, previously trained and the results were sub- mitted statistical analysis, using Fisher’s exact test to compare the proportion of deviation obtained by both techniques. The data obtained allowed to conclude that Hero 642 rotatory system showed less root canals with deviation in the apical third than NiTi manual files, al- though, these results weren’t sta- tistically significant. Key words: root canal prepara- tion, morphologic alterations, ins- trumentation techniques, instru- mentation, Hero 642.