ABSTRACT
ABSTRACT: The aim of this study was to compare the cyclic fatigue resistance (CFR) of PathFile (Dentsply Sirona, Ballaigues, Switzerland) and ScoutRace (FKG Dentaire, La Chaux-de-Fonds, Switzerland) glide path files which were either new or previously used. Forty PathFile (PF) 19/.02 and 40 ScoutRace (SR) 20/.02 instruments were used for this study. Half of the files in each group were used (PF-U and SR-U) in the 3D demo tooth models (FKG Dentaire, La Chaux-de-Fonds, Switzerland) for creating glide paths, while the other half was new (PF-N and SR-N) and directly subjected to the cyclic fatigue test. The new and used files (n=80) were rotated in the cyclic fatigue test device with an artificial stainless-steel canal (60° curvature, 5 mm radius 1.5 mm width and 3.0 mm depth) under the continuous irrigation with distilled water at 37°C until fracture occurred. Time to fracture was recorded and the Weibull reliability analysis was performed. Data were statistically analysed. Conformity to normal distribution was examined using the Shapiro-Wilk test. A paired two-sample t-test was used to compare the TTF values according to the time within the groups. The new instruments (PF-N and SR-N) showed better CFR than the used groups (PF-U and SR-U) (P SR-N>PF-U>SR-U. Reuse of both glide path instruments reduced the time to fracture and the cyclic fatigue resistance of the files.
RESUMEN: El objetivo de este estudio fue comparar la resistencia a la fatiga cíclica (CFR en inglés) de las limas PathFile (Dentsply Sirona, Ballaigues, Suiza) y ScoutRace (FKG Dentaire, La Chaux-de-Fonds, Suiza) de tipo glide path, nuevas o ya previamente utilizadas. Para este estudio se utilizaron 40 instrumentos PathFile (PF) 19/.02 y 40 ScoutRace (SR) 20/.02. La mitad de las limas de cada grupo se utilizaron (PF-U y SR-U) en los modelos dentales de demostración 3D (FKG Dentaire, La Chaux-de- Fonds, Suiza) para crear trayectorias de deslizamiento, mientras que la otra mitad se utilizaron nuevas directamente a la prueba de fatiga cíclica (PF-N y SR-N). Las limas nuevas y usadas (n=80) se hicieron girar en el dispositivo de prueba de fatiga cíclica con un canal artificial de acero inoxidable (curvatura de 60°, radio de 5mm, anchura de 1,5mm y profundidad de 3,0mm) bajo irrigación continua con agua destilada a 37°C hasta que se produjo la fractura. Se registró el tiempo hasta la fractura y se realizó el análisis de fiabilidad de Weibull. Los datos se analizaron estadísticamente. La conformidad con la distribución normal se examinó mediante la prueba de Shapiro- Wilk. Se utilizó una prueba t de dos muestras pareadas para comparar los valores de TTF según el tiempo dentro de los grupos. Los instrumentos nuevos (PF-N y SR- N) mostraron una mejor CFR que los grupos previamente utilizados (PF-U y SR-U) (p SR-N >PF-U >SR-U. La reutilización de ambos instrumentos tipo glide path redujo el tiempo hasta la fractura y la resistencia a la fatiga cíclica de las limas.
Subject(s)
Equipment Reuse , Dental InstrumentsABSTRACT
Objective: The objective of this study is to compare the cyclic fatigue resistance of nine types of endodontic instruments of nickel–titanium. Materials and Methods: Five files of 25 mm of length of each group: Reciproc (RC) R25; WaveOne (WO) Primary; Unicone (UC) L25 25/0.06; K3XF 25/0.06; ProTaper Universal F2 (PTF2); ProTaper Next X2 (PTX2); Mtwo 25/0.06; BioRaCe 25/0.06; One Shape L25 25/0.06 were subjected to a cyclic fatigue resistance test on a mechanical apparatus. The mean fracture time was analyzed statistically by one-way analysis of variance and Tukey’s honest significant difference post hoc test, with significance set at P < 0.05. Conclusion: It was observed that the groups PTX2, RC, R25, UC L25 25/0.06, and WO Primary presented greater cyclic fracture resistance than the other groups (P < 0.001).