Evaluation of dynamic Cyclic fatigue resistance of three different Rotary Nickel Titanium systems. (invitro study)Menna Allah Taha Abdelkader Elshhaby; Medhat El Faramawy; Wael El Shatter Endodontics Department, Faculty of dentistry, Ain Shams Univer

Abstract

Background: Mechanical preparation that is fast, safe, and effective without affecting the natural morphology of the canal is made possible with nickel-titanium (Ni-Ti) instruments due to their low modulus of elasticity and excellent flexibility. They exhibit unique property of shape memory and super elasticity, but unfortunately these rotary instrument shows unexpected fracture because of cyclic fatigue or/and torsional overload.Aim of the work: The objective of this investigation was to evaluate the dynamic cyclic fatigue performance of three rotary file systems: "Protaper Next," "edgx7," and "Trunatomy."Materials and methods: Dynamic cycle fatigue was tested with 30 files from these systems utilizing a specific instrument. The number of cycles to fracture NCF was calculated using a given function. By scanning representative samples from all the previous groups of files using SEM, we were able to evaluate the mode of fracture. Tukey's Post Hoc and one-way ANOVA were used to determine group differences.Result: ANOVA illustrated that there was significant distinction amongst the three groups (P=0.0001). The fatigue resistance was highest in Edgex3, then in Trunatomy prime, as well as lowest in Protaper next x2.Conclusion: The dynamic cyclic fatigue resistance of the EdgeX3 was the greatest due to the fire wire technology followed by the Trunatomy prime and then Protaper next x2 showed the least.