Cyclic Fatigue of Glide Path Rotary NiTi Files in a Double (S-Shaped) Simulated Curvature

Dina Al-Sudani,Gianluca Plotino

doi:10.4172/2161-1122.1000355

Dina Al-Sudani, Gianluca Plotino

Open Access

https://doi.org/10.4172/2161-1122.1000355

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Journal: Dentistry	Publication Date: Jan 1, 2016
Citations: 3	License type: cc-by

Affiliation: King Saud University, Sapienza University of Rome

Abstract

Objective: The aim of the present study was to compare the fatigue resistance of PathFile (PF) and ProGlider (PG) NiTi (Nickel-Titanium) rotary files in a double (S-shaped) curvature artificial root canal. Methods: The cyclic fatigue of the following rotary NiTi glide path instruments was tested in a double curvature artificial canal, PF (tip size .16 and .02 taper) and PG (tip size .16 and variable taper). Twenty instruments for each group were tested to fracture in continuous rotary motion at 300 rpm. The number of cycles to failure (NCF) was calculated and the length of the fractured fragment was measured. Data were statistically analyzed with a level of significance set at 5%. Results: There was no significant difference in cyclic fatigue resistance between the PF and the PG in the apical curvature (p>0.05). However, in the coronal curvature the NCF value was significantly higher for the PG than for the PF (p 0.05). Conclusion: The instruments were found to be less resistant to cyclic fatigue in the apical curvature of the artificial canal than in the coronal curvature. PG instrument showed significantly greater cyclic fatigue resistance in the coronal curvature.

Highlights

One of the main goals of the manufacturers of Nickel-Titanium (NiTi) rotary instruments is to reduce the likelihood of instrument separation and improve safety through innovative design and manufacturing processes [1,2]
Mean values ± standard deviations (SD) expressed as number of cycles to failure (NCF) are displayed in (Table 1)
In the double curvature model, there was no significant difference in cyclic fatigue between the PF and the PG in the apical curvature

Summary

Introduction

One of the main goals of the manufacturers of Nickel-Titanium (NiTi) rotary instruments is to reduce the likelihood of instrument separation and improve safety through innovative design and manufacturing processes [1,2]. Cyclic fatigue and torsional fracture are the two main mechanisms that may lead to instrument separation, mainly caused by bending and torsional stress [3]. One of the recommendations to reduce fracture risk of NiTi instruments is to create a glide path during the initial preparation [5]. The endodontic glide path, which has been described as having sufficient patency from the canal orifice to the apical foramen, is performed using smallsized and slightly tapered NiTi rotary instruments or stainless-steel manual files [5]. The creation of a glide path may facilitate root canal preparation when NiTi instruments with larger tapers are used and reduce the incidence of procedural errors [6,7]

Methods

Results

Discussion

Conclusion