Comparative Analysis of Ease of Removal of Fractured NiTi Endodontic Rotary Files from the Root Canal System—An In Vitro Study

Abstract

This study aimed at analyzing and comparing the ease of removal of fractured nickel–titanium (NiTi) endodontic rotary files from the root canal system between the ultrasonic tips and the Endo Rescue appliance removal systems, as well as comparing the volume of dentin removed between ultrasonic tips and the Endo Rescue appliance using a micro-computed tomography (micro-CT) scan. Material and Methods: Forty NiTi endodontic rotary files were intentionally fractured in 40 root canal systems of 20 lower first molar teeth and distributed into the following study groups: A: Ultrasonic tips (n = 20) (US) and B: Endo Rescue device (n = 20) (ER). Preoperative and postoperative micro-CT scans were uploaded into image processing software to analyze the volumetric variations of dentin using an algorithm that enables progressive differentiation between neighboring pixels after defining and segmenting the fractured NiTi endodontic rotary files and the root canal systems in both micro-CT scans. A non-parametric Mann–Whitney–Wilcoxon test or t-test for independent samples was used to analyze the results. Results: The US and ES study groups saw 8 (1 mesiobuccal and 7 distal root canal system) and 3 (distal root canal system) fractured NiTi endodontic rotary files removed, respectively. No statistically significant differences were found in the amount of dentin removed between the US and ER study groups at the mesiobuccal (p = 0.9109) and distal root canal system (p = 0.8669). Conclusions: Ultrasonic tips enable greater ease of removal of NiTi endodontic rotary files from the root canal system, with similar amounts of dentin removal between the two methods.

Efficacy of Two Separated File Removal Systems. (A Comparative Vitro Study)

“…The ProTaper Next X2 rotary file was partially notched to half of the instrument thickness with a diamond disc mounted on a low-speed handpiece, as per Faus-Matoses et al (14) , at 5mm from the tip. The file was introduced into the mesiobuccal canal, and at a speed of 350 rpm and torque of 3.5 N, it was rotated with pressure until separation at a depth of three mm apical to the canal orifice to be visible under the DOM.…”

Effect of Intermediate Irrigation on Temperature Rise during Broken NiTi File Removal Using Ultrasonic Device

“…When instrument fracture occurs, several treatment strategies can be used: trying to remove the instrument, attempting to bypass the instrument, or sealing the root segment occupied by the broken instrument [3]. Studies using ultrasonic instrumentation to remove broken segments have reported favorable results [4], with success rates of 54.4% to 93.3%. Ultrasonic file removal methods are mostly based on the Ruddle technique or a variation of it [5].…”

“…Ultrasonic file removal methods are mostly based on the Ruddle technique or a variation of it [5]. A platform is created using a Gates-Glidden drill (2)(3)(4) prior to instrument use. The Gates-Glidden drill is modified by cutting through the maximum cross-sectional diameter perpendicular to its longitudinal axis.…”