IMR Press / FBL / Volume 26 / Issue 9 / DOI: 10.52586/4959
Open Access Original Research
Characterization of the differential efficacy of austenitic vs martensitic NiTi rotary files in non-surgical root canal retreatment: a micro-CT analysis
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1 Department of Endodontics, Faculty of Dentistry, King Abdulaziz University, 21589 Jeddah, Saudi Arabia
2 Ministry of Health, 21 Yehea Almoalmy, Alrabwah, 23222 Jeddah, Saudi Arabia
3 Department of Dental Public Health, Faculty of Dentistry, King Abdulaziz University, 21589 Jeddah, Saudi Arabia
4 Department of Restorative Dentistry, Faculty of Dentistry, King Abdulaziz University, 21589 Jeddah, Saudi Arabia
*Correspondence: (Loai Alsofi)
Front. Biosci. (Landmark Ed) 2021, 26(9), 465–474;
Submitted: 23 May 2021 | Revised: 7 July 2021 | Accepted: 27 July 2021 | Published: 30 September 2021
(This article belongs to the Special Issue NiTi Rotary Instruments in Endodontics)
Copyright: © 2021 The Author(s). Published by BRI.
This is an open access article under the CC BY 4.0 license (

Aim: Our study aims to characterize the differential efficacy of martensitic and austenitic files in root canal retreatment regarding defiling ability, debris management and morphometric features. Materials and methods: A total of 10 human premolar teeth with two separate fully formed roots were selected, prepared with BioRace system (BR) up to a size BR2 (0.04/25). Root canals were filled and then divided according to the file type into two groups (n = 10). Two geometrically identical files have been used with the only difference between them is heat treatment; One Curve (OC) martensitic and One Shape (OS) austenitic. Preoperative and postoperative Micro-CT scans were done for all the samples, and the percent volume of residual filling materials was calculated. Canals reshaping and remaining debris in the canals were assessed by calculating the volume of the canals before and after retreatment using Micro-CT software. Results: The percentages of removed filling materials were similar between both groups (97.2% OC vs 97.8% OS). OS was significantly faster than OC (P < 0.05). Retreatment procedure did not significantly change volume, structure model index, surface area, and canal curvature. OS group transported the canals more than OC at the apical third (P < 0.05). There were no significant differences between both groups concerning un-instrumented surface area and accumulated hard tissue debris (AHTD) (P > 0.05). Conclusion: Under the circumstances of this study, neither file systems could completely remove the filling materials. However, OC resulted in less transportation than OS in the apical one third (P < 0.05). Also, OC resulted less AHTD than OS but with no statistical difference.

One Curve
One Shape
Rotary files
Fig. 1.
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