Ultrastructural analysis of the surface changes on the nickel-titanium endodontic instruments after multiple use

One of the primary goals in endodontics is efficient cleaning and shaping root canal while maintaining its original configuration. Numerous studies highlight advantage using nickel-titanium instruments most important their high flexibility ability to penetrate curved canals. The aim this study was analyze ultrastructure surface endodontic files before after use. Eighty-four were included study. used one, three six times for preparation on extracted upper premolars. analysis performed based number uses size instruments. Changes flat surfaces grooves instruments, defects cutting edges fractures evaluated. analyzed a scanning electron microscope (SEM). SEM showed irregularities new Surface damage present first After uses, more evident all sizes. edges, significant observed. Irregularities working parts are already noticed originate from production process. signs appear In order prevent errors clinical work during preparation, it recommended that should be limited.