Introduction: The aim of the study was to evaluate resistance to flexural fatigue of Reciproc R25, WaveOne Primary, Mtwo and Twisted File used in continuous rotation or in two different reciprocating motions. Materials & Methods: A total of 180 nickel-titanium files from four brands marketed, two for use in reciprocating motion (Reciproc R25 and WaveOne Primary), and two for use in continuous rotation (Mtwo and Twisted File both taper .06/0.25 tip diameter) were tested. Forty-five instruments for each brand were divided into three groups (n=15) on the basis of the motion tested: continuous rotation (group 1 - 300 rpm); reciprocal motion (group 2 - "Reciproc ALL" mode and group 3 - "WaveOne ALL" mode). Resistance to cyclic fatigue was determined by counting the number of cycles to failure (NCF) in a 60° curve with a 5-mm radius. Data was analyzed through two-way analyses of variance. Results: The Cyclic fatigue resistance of the two reciprocating motion "Reciproc ALL" and "WaveOne ALL" was significantly higher than the continuous rotation in each brand (P<0.001). Whereas, no significant difference was found in the cyclic fatigue between the two different reciprocal motions tested in each brand (P>0.05). When considering the appropriate clinical motion for each brand no significant difference in cyclic fatigue was found between Twisted File, Mtwo and Reciproc R25, while the cyclic fatigue resistance of WaveOne was less than the other three brands (P<0.05) Conclusions: Reciprocal motion showed a significantly higher cyclic fatigue resistance in all brands compared to continuous rotation). No differences were found between the two reciprocating motions.
|Titolo:||Influence of Continuous or Reciprocating Motion on Cyclic Fatigue Resistance of Four different Nickel-Titanium Rotary Instruments.|
|Data di pubblicazione:||2013|
|Appare nelle tipologie:||1.1 Articolo in rivista|