| Autor: |
Faus-Matoses V; Department of Stomatology, Faculty of Medicine and Dentistry, University of Valencia, 46010 Valencia, Spain., Faus-Llácer V; Department of Stomatology, Faculty of Medicine and Dentistry, University of Valencia, 46010 Valencia, Spain., Ruiz-Sánchez C; Department of Stomatology, Faculty of Medicine and Dentistry, University of Valencia, 46010 Valencia, Spain., Jaramillo-Vásconez S; Department of Stomatology, Faculty of Medicine and Dentistry, University of Valencia, 46010 Valencia, Spain., Faus-Matoses I; Department of Stomatology, Faculty of Medicine and Dentistry, University of Valencia, 46010 Valencia, Spain., Martín-Biedma B; Department of Surgery and Medical-Surgical Specialties, School of Medicine and Dentistry, Universidad de Santiago de Compostela, 15705 Santiago de Compostela, Spain., Zubizarreta-Macho Á; Department of Implant Surgery, Faculty of Health Sciences, Alfonso X El Sabio University, 28691 Madrid, Spain.; Department of Surgery, Faculty of Medicine and Dentistry, University of Salamanca, 37008 Salamanca, Spain. |
| Abstrakt: |
The present study aims to evaluate and contrast the function of the rotational speed of NiTi alloy endodontic rotary files on how resistant they are to dynamic cyclic fatigue. Methods: A total of 150 NiTi alloy endodontic rotary files with similar geometrical design and metallurgical properties were randomly divided into study groups: Group A: 200 rpm (n = 30); Group B: 350 rpm (n = 30); Group C: 500 rpm (n = 30); Group D: reciprocating movement at 350 rpm with 120° counterclockwise and 30° clockwise motion (350 rpm+) (n = 30); and Group E: reciprocating movement at 400 rpm with 120° counterclockwise and 30° clockwise motion (400 rpm+) (n = 30). A dynamic device was designed to carry out dynamic cyclic fatigue tests using artificial root canal systems made from stainless steel with an apical diameter of 250 µm, 5 mm radius of curvature, 60° curvature angle, and 6% taper, and 20 mm in length. A Weibull statistical analysis and ANOVA test were used to analyze the results. Results: The ANOVA analysis showed differences in time to failure among all the study groups that were of statistical significance (p < 0.001). Conclusions: NiTi alloy endodontic rotary files using reciprocating movement at 350 rpm with 120° counterclockwise and 30° clockwise motion exhibit greater resistance to dynamic cyclic fatigue than files used with a reciprocating movement at 400 rpm with 120° counterclockwise and 30° clockwise motion, continuous rotational speed at 200 rpm, continuous rotational speed at 350 rpm, or continuous rotational speed at 500 rpm; it is therefore advisable to use reciprocating movements at a low speed. |
