Effect of repeated use on topographical features of protaper next endodontic rotary file

Abstract

Background: The purpose of this study was to evaluate the morphological alterations of the ProTaper next rotary file (PTN) under scanning electron microscopy (SEM). Materials and Methods: A total of 18 simulated root canals were allocated to three groups. Six new sets of PTN instruments were used 3 times. A #10 K-file was inserted into the working length, followed by ProGlider to create a glide path. Ensuring the manufacturers instructions with 99% ethyl alcohol for irrigation, all canals were prepared. Files were photographed in the same position before and after three canals preparations using a high-resolution SEM. Result: A metal strip appeared on one X1 instrument surface preoperatively. Microcrack defects were observed on two X2 files postoperatively, and the blunt cutting edge was observed on three X1 files before and after use and one file fractured. Conclusion: Small number of changes appeared on PTN surfaces, yet same PTN file can be used safely 3 times to prepare multi-rooted teeth within the same patient.