Infuence of the type of reciprocating motion on the cyclic fatigue resistance of reciprocating fles in a dynamic model

Abstract

Background: The aim of this study was to compare the infuence of two novel reciprocating movements on the cyclic fatigue resistance of endodontic reciprocating fles. Methods: 30 Procodile® (Komet Medical, Lemgo, Germany) fles were selected in this study and distributed accord¿ ing to the following study groups depending on the movements to be performed: ReFlex Dynamic (n=10), ReFlex Smart (n=10) and Reciproc (n=10) reciprocating movement. These fles were fxed to a specifc dynamic cyclic fatigue device designed and manufactured by 3D impression to simulate the pecking motion performed by the operator. The time to failure and the number of cycles of in-and-out of the endodontic fles was registered. The results were analyzed by ANOVA and Weibull statistics. Results: Statistically signifcant diferences were found when the number of cycles of in-and-out movement and the time to failure of ReFlex Dynamic and Reciproc reciprocating movement (p < 0.001) and between ReFlex Smart and Reciproc reciprocating movement (p < 0.001) were compared in pairs. However, no statistically signifcant diferences were observed between time to failure and number of cycles of in-and-out movement of ReFlex Dynamic and ReFlex Smart reciprocating movement (p=0.253). Conclusions: The ReFlex Smart reciprocating movement increased the cyclic fatigue resistance of endodontic recip¿ rocating fles compared with traditional reciprocating movement. Keywords: Endodontics, Cyclic fatigue, Nitinol, Reciprocating movement