Introduction: The purpose of this study was to evaluate the torsional and cyclic fatigue resistance of the new HyflexEDM OneFile (Coltene/Whaledent AG, Altstatten, Switzerland) manufactured by electrical discharge machining and compare the findings with the ones ofReciproc R25 (VDW, Munich, Germany) and WaveOne Primary (Dentsply Maillefer, Ballaigues, Switzerland).Methods: One hundred-twenty new Hyflex EDM One- File (#25/0.08), Reciproc R25, and WaveOne Primaryfiles were used. Torque and angle of rotation at failure of new instruments (n = 20) were measured accordingto ISO 3630-1 for each brand. Cyclic fatigue resistance was tested measuring the number of cycles to failurein an artificial stainless steel canal with a 60 angle and a 3-mm radius of curvature. Data were analyzed using the analysis of variance test and the Student-Newman-Keuls test for multiple comparisons. The fracture surface of each fragment was examined with a scanning electron microscope. Results: The cyclic fatigueof Hyflex EDM was significantly higher than the one of Reciproc R25 and WaveOne Primary (P < .05 and P < .001, respectively). Hyflex EDM showed a lowermaximum torque load (P < .05) but a significantly higher angular rotation (P < .0001) to fracture than Reciproc R25 and WaveOne Primary. No significant difference was found comparing the maximum torque load, angular rotation, and cyclic fatigue of Reciproc R25and WaveOne Primary (P > .05). Conclusions: The new Hyflex EDM instruments (controlled memory wire)have higher cyclic fatigue resistance and angle of rotation to fracture but lower torque to failure than ReciprocR25 and WaveOne Primary files (M-wire for both files).
|Titolo:||Torsional and Cyclic Fatigue Resistance of a New Nickel-titanium Instrument Manufactured by Electrical Discharge Machining|
PEDULLA', EUGENIO [Writing – Original Draft Preparation] (Corresponding)
|Data di pubblicazione:||2016|
|Appare nelle tipologie:||1.1 Articolo in rivista|