Comparative study of dynamic cyclic fatigue resistance of two files with different kinematics

Abstract

Objectives: The aim of the study was to determine the dynamic cyclic fatigue resistance (DCFR) of R-motion file and Protaper Next file (PTN) by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM).

Methods: R-motion file (25/.06), PTN file (25/.06) were used and divided into 2 groups (n = 28) according to the file type. DCFR was performed using an artificial canal. Files were allowed to work until separation. The numbers of cycles to failure (NCF) and the time to fracture (TTF) were calculated. The files were subjected to DSC and SEM.

Results: R-motion files had higher NCF and TTF compared to PTN files. SEM examination showed that all files showed ductile fracture. DSC of the R-motion file displayed Austenitic phase at body temperature) 37 ˚C) while PTN file failed to demonstrate any peaks within the applied heat range. Conclusions: R-motion files had higher CFR and TTF than PTN files.

Conclusions: R-motion files had higher CFR and TTF than PTN files.