Effectivness of cleaning procedures on rotary nickel-titanium files: a SEM analysis.

AIM:The purpose of the present study was to quantify the surface debris on endodontic nickel-titanium rotary files after cleaning procedures.MATERIALS AND METHODS:Rotary nickel-titanium files (ProFiles and MTwo) were examined after removal from the packaging, after instrumentation in human teeth, and after various cleaning procedures. The cleaning procedures consisted of either ultrasonication with the files placed in a perforated container or ultrasonication with the files loosely placed in a beaker, with various cleaning agents. The presence of debris was evaluated using scanning electron microscopy. Specimens were scored accordingly to a 0-4 scale by two independent observers, whose agreement was previously evaluated using Cohen-K test. Data were analyzed with Kruskal Wallis and Mann-Whitney test for significativity. RESULTS:Some files were delivered from the factory with machining debris. The effectiveness of cleaning procedures with or without enzymatic products was different with p<0,001. Cleaning the files by ultrasonication within a container did not consistently achieve complete removal of debris. Placing the files loosely in the ultrasonic bath achieved the most effective cleaning.CONCLUSIONS:A conventional cleaning method is capable of effectively removing debris from endodontic files.