Resistance to cyclic fatigue of Reciproc and MTwo files on continuous rotation and reciprocating movements

Giulio GAVINI, Eduardo AKISUE, Dirce Akemi Sacaguti KAWAKAMI, Celso Luiz CALDEIRA, Gustavo de DEUS, Murilo Priori ALCALDE, George Táccio de Miranda CANDEIRO

Objective: The aim of present study was to evaluate the influence of alloy (conventional NiTi and M-Wire NiTi) and movement (reciprocating movement and continuous rotation) on resistance to cyclic fatigue. Methods: Fifteen Reciproc R25 files (VDW GmbH, Munich, Germany) were used in reciprocation motion (RM), while thirty MTwo 25/.07 files (VDW GmbH, Munich, Germany) were used either in RM (n=15) or in continuous rotation (CR) (n=15). The files were submitted to dynamic assays device moved by electric engine that allowed the reproduction of pecking motion under 300 rpm of speed. The files act simulating the instrumentation of a curved root canal with 40º and 5-mm of curvature radius. The fracture was detected by the device sensor and the time and number of cycles were obtained. Data were statistically analyzed by ANOVA and Tukeys tests (p<0.05). Results: The Reciproc R25 instruments moved by RM reached significantly higher number (p<0.05) of cycles before fracture (1777.68 ± 334.2 cycles) when compared with MTwo 25/.07 instruments moved by RM (610.67 ± 126.3 cycles) or CR (432.23 ± 183.2 cycles). Conclusions: The reciprocation motion showed significantly greater cyclic fatigue resistance and the M-Wire NiTi files showed higher cyclic fatigue resistance than conventional NiTi rotary files.

Keywords: Fatigue. Dental Instruments. Endodontics.

How to cite: Gavini G, Akisue E, Kawakami DAS, Caldeira CL, Deus G, Alcalde MP, Candeiro GTM. Resistance to cyclic fatigue of Reciproc and Mwto files on continuous rotation and reciprocating movements. Dental Press Endod. 2020 May-Aug;10(2):42-7.

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