TY - JOUR
T1 - Structural integrity of endodontic files using rotating bending tests, transient thermography and eddy currents testing
AU - Saldanha, Guilherme
AU - Machado, Miguel A.
AU - Santos, Telmo G.
AU - Martins, Rui F.
N1 - info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F00667%2F2020/PT#
Publisher Copyright:
© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the 23 European Conference on Fracture - ECF23.
PY - 2022
Y1 - 2022
N2 - One of the purposes of this study is to compare the fatigue resistance of different generations of endodontic files made of nickel-titanium (NiTi). Additionally, it is intended to investigate the possibility of using Non-Destructive Testing (NDT), mainly eddy currents testing (ECT) and thermography, to detect fatigue microcracks responsible for most of the fractures of the endodontic files in a clinical environment. The instruments were placed in rotation in an experimental setup designed to simulate a root canal with a radius of curvature of 5 mm applied over an angle of 45°. HyFlex™ EDM rotary files (Coltene, Switzerland) were tested and compared with the results obtained for HyFlex™ CM conventional machined files. Experimental results showed that the recent generation of instruments manufactured by the Electrical Discharge Machining (EDM) process is much more resistant to fatigue when compared to the conventional controlled memory (CM) files. For the NDT application, an artificial defect was introduced in the apical region of a HyFlex CM file. Subsequently, ten customized ECT probes were designed, produced, and validated experimentally. In addition, numerical simulations were carried out, replicating the parameters and conditions of the two probes that showed better detectability. The methodologies developed for the inspection of files through ECT proved unable to detect the faulty region unambiguously, mainly due to NiTi alloys' taper and the electromagnetic properties. On the other hand, thermography allowed to detect the defect introduced in the endodontic file, although with some difficulty due to its small size.
AB - One of the purposes of this study is to compare the fatigue resistance of different generations of endodontic files made of nickel-titanium (NiTi). Additionally, it is intended to investigate the possibility of using Non-Destructive Testing (NDT), mainly eddy currents testing (ECT) and thermography, to detect fatigue microcracks responsible for most of the fractures of the endodontic files in a clinical environment. The instruments were placed in rotation in an experimental setup designed to simulate a root canal with a radius of curvature of 5 mm applied over an angle of 45°. HyFlex™ EDM rotary files (Coltene, Switzerland) were tested and compared with the results obtained for HyFlex™ CM conventional machined files. Experimental results showed that the recent generation of instruments manufactured by the Electrical Discharge Machining (EDM) process is much more resistant to fatigue when compared to the conventional controlled memory (CM) files. For the NDT application, an artificial defect was introduced in the apical region of a HyFlex CM file. Subsequently, ten customized ECT probes were designed, produced, and validated experimentally. In addition, numerical simulations were carried out, replicating the parameters and conditions of the two probes that showed better detectability. The methodologies developed for the inspection of files through ECT proved unable to detect the faulty region unambiguously, mainly due to NiTi alloys' taper and the electromagnetic properties. On the other hand, thermography allowed to detect the defect introduced in the endodontic file, although with some difficulty due to its small size.
KW - Eddy Currents Testing (ECT)
KW - Endodontic files
KW - Fatigue resistance
KW - Structural integrity
KW - Thermography
UR - http://www.scopus.com/inward/record.url?scp=85158972697&partnerID=8YFLogxK
U2 - 10.1016/j.prostr.2022.12.080
DO - 10.1016/j.prostr.2022.12.080
M3 - Conference article
AN - SCOPUS:85158972697
SN - 2452-3216
VL - 42
SP - 631
EP - 638
JO - Procedia Structural Integrity
JF - Procedia Structural Integrity
T2 - 23rd European Conference on Fracture, ECF 2022
Y2 - 27 June 2022 through 1 July 2022
ER -