Cargando…

Phase transformation and mechanical properties of heat-treated nickel-titanium rotary endodontic instruments at room and body temperatures

BACKGROUND: The aim of this study was to evaluate the phase composition, phase transformation temperatures, bending property, and cyclic fatigue resistance of different heat-treated nickel-titanium (NiTi) rotary instruments with the same tip diameter and taper at room (RT; 25 ± 1 °C) and body (BT; 3...

Descripción completa

Detalles Bibliográficos
Autores principales: Kasuga, Yuka, Kimura, Shunsuke, Maki, Keiichiro, Unno, Hayate, Omori, Satoshi, Hirano, Keiko, Ebihara, Arata, Okiji, Takashi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10614384/
https://www.ncbi.nlm.nih.gov/pubmed/37904159
http://dx.doi.org/10.1186/s12903-023-03550-6
_version_ 1785129018382614528
author Kasuga, Yuka
Kimura, Shunsuke
Maki, Keiichiro
Unno, Hayate
Omori, Satoshi
Hirano, Keiko
Ebihara, Arata
Okiji, Takashi
author_facet Kasuga, Yuka
Kimura, Shunsuke
Maki, Keiichiro
Unno, Hayate
Omori, Satoshi
Hirano, Keiko
Ebihara, Arata
Okiji, Takashi
author_sort Kasuga, Yuka
collection PubMed
description BACKGROUND: The aim of this study was to evaluate the phase composition, phase transformation temperatures, bending property, and cyclic fatigue resistance of different heat-treated nickel-titanium (NiTi) rotary instruments with the same tip diameter and taper at room (RT; 25 ± 1 °C) and body (BT; 37 ± 1 °C) temperatures. METHODS: Five heat-treated NiTi rotary instruments, HyFlex EDM (EDM), HyFlex CM (CM), Vortex Blue (VB), RE file CT (RE) and JIZAI, and a non-heat-treated NiTi rotary instrument (Mtwo) with a size 40, 0.04 taper were investigated. Temperature-dependent phase transformation was examined with differential scanning calorimetry (DSC). The bending loads of the instruments at RT and BT were evaluated using a cantilever-bending test. Cyclic fatigue resistance at RT and BT was measured using a dynamic test, during which the instruments were rotated in combination with a 2-mm back-and-forth motion in an artificial curved canal, and the number of cycles to failure (NCF) was determined. The results were analyzed using two-way repeated measures analysis of variance, a simple main effect test, and the Bonferroni test (α = 0.05). RESULTS: DSC results indicated that EDM and Mtwo were primarily composed of martensite/R-phase and austenite, respectively, while the other heat-treated instruments were composed of a mix of martensite/R-phase and austenite at the tested temperatures. Regardless of the temperature setting, the bending loads of heat-treated instruments were significantly lower than those of Mtwo (p < 0.05). EDM showed the lowest bending loads and highest NCF at both temperatures (p < 0.05). CM, VB, and JIZAI showed significantly higher bending loads at BT than at RT (p < 0.05). The NCF of all the heat-treated instruments, except VB, was lower at BT than at RT (p < 0.05). At BT, the NCF of CM, VB, RE, and JIZAI were not significantly higher than that of Mtwo (p > 0.05). CONCLUSIONS: Heat-treated NiTi instruments exhibited lower bending loads and higher NCF values than Mtwo. However, this tendency was less pronounced at BT than at RT, especially in the NCF values of instruments with a mixture of martensite/R-phase and austenite phases at the tested temperatures.
format Online
Article
Text
id pubmed-10614384
institution National Center for Biotechnology Information
language English
publishDate 2023
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-106143842023-10-31 Phase transformation and mechanical properties of heat-treated nickel-titanium rotary endodontic instruments at room and body temperatures Kasuga, Yuka Kimura, Shunsuke Maki, Keiichiro Unno, Hayate Omori, Satoshi Hirano, Keiko Ebihara, Arata Okiji, Takashi BMC Oral Health Research BACKGROUND: The aim of this study was to evaluate the phase composition, phase transformation temperatures, bending property, and cyclic fatigue resistance of different heat-treated nickel-titanium (NiTi) rotary instruments with the same tip diameter and taper at room (RT; 25 ± 1 °C) and body (BT; 37 ± 1 °C) temperatures. METHODS: Five heat-treated NiTi rotary instruments, HyFlex EDM (EDM), HyFlex CM (CM), Vortex Blue (VB), RE file CT (RE) and JIZAI, and a non-heat-treated NiTi rotary instrument (Mtwo) with a size 40, 0.04 taper were investigated. Temperature-dependent phase transformation was examined with differential scanning calorimetry (DSC). The bending loads of the instruments at RT and BT were evaluated using a cantilever-bending test. Cyclic fatigue resistance at RT and BT was measured using a dynamic test, during which the instruments were rotated in combination with a 2-mm back-and-forth motion in an artificial curved canal, and the number of cycles to failure (NCF) was determined. The results were analyzed using two-way repeated measures analysis of variance, a simple main effect test, and the Bonferroni test (α = 0.05). RESULTS: DSC results indicated that EDM and Mtwo were primarily composed of martensite/R-phase and austenite, respectively, while the other heat-treated instruments were composed of a mix of martensite/R-phase and austenite at the tested temperatures. Regardless of the temperature setting, the bending loads of heat-treated instruments were significantly lower than those of Mtwo (p < 0.05). EDM showed the lowest bending loads and highest NCF at both temperatures (p < 0.05). CM, VB, and JIZAI showed significantly higher bending loads at BT than at RT (p < 0.05). The NCF of all the heat-treated instruments, except VB, was lower at BT than at RT (p < 0.05). At BT, the NCF of CM, VB, RE, and JIZAI were not significantly higher than that of Mtwo (p > 0.05). CONCLUSIONS: Heat-treated NiTi instruments exhibited lower bending loads and higher NCF values than Mtwo. However, this tendency was less pronounced at BT than at RT, especially in the NCF values of instruments with a mixture of martensite/R-phase and austenite phases at the tested temperatures. BioMed Central 2023-10-30 /pmc/articles/PMC10614384/ /pubmed/37904159 http://dx.doi.org/10.1186/s12903-023-03550-6 Text en © The Author(s) 2023 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) . The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/ (https://creativecommons.org/publicdomain/zero/1.0/) ) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
spellingShingle Research
Kasuga, Yuka
Kimura, Shunsuke
Maki, Keiichiro
Unno, Hayate
Omori, Satoshi
Hirano, Keiko
Ebihara, Arata
Okiji, Takashi
Phase transformation and mechanical properties of heat-treated nickel-titanium rotary endodontic instruments at room and body temperatures
title Phase transformation and mechanical properties of heat-treated nickel-titanium rotary endodontic instruments at room and body temperatures
title_full Phase transformation and mechanical properties of heat-treated nickel-titanium rotary endodontic instruments at room and body temperatures
title_fullStr Phase transformation and mechanical properties of heat-treated nickel-titanium rotary endodontic instruments at room and body temperatures
title_full_unstemmed Phase transformation and mechanical properties of heat-treated nickel-titanium rotary endodontic instruments at room and body temperatures
title_short Phase transformation and mechanical properties of heat-treated nickel-titanium rotary endodontic instruments at room and body temperatures
title_sort phase transformation and mechanical properties of heat-treated nickel-titanium rotary endodontic instruments at room and body temperatures
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10614384/
https://www.ncbi.nlm.nih.gov/pubmed/37904159
http://dx.doi.org/10.1186/s12903-023-03550-6
work_keys_str_mv AT kasugayuka phasetransformationandmechanicalpropertiesofheattreatednickeltitaniumrotaryendodonticinstrumentsatroomandbodytemperatures
AT kimurashunsuke phasetransformationandmechanicalpropertiesofheattreatednickeltitaniumrotaryendodonticinstrumentsatroomandbodytemperatures
AT makikeiichiro phasetransformationandmechanicalpropertiesofheattreatednickeltitaniumrotaryendodonticinstrumentsatroomandbodytemperatures
AT unnohayate phasetransformationandmechanicalpropertiesofheattreatednickeltitaniumrotaryendodonticinstrumentsatroomandbodytemperatures
AT omorisatoshi phasetransformationandmechanicalpropertiesofheattreatednickeltitaniumrotaryendodonticinstrumentsatroomandbodytemperatures
AT hiranokeiko phasetransformationandmechanicalpropertiesofheattreatednickeltitaniumrotaryendodonticinstrumentsatroomandbodytemperatures
AT ebiharaarata phasetransformationandmechanicalpropertiesofheattreatednickeltitaniumrotaryendodonticinstrumentsatroomandbodytemperatures
AT okijitakashi phasetransformationandmechanicalpropertiesofheattreatednickeltitaniumrotaryendodonticinstrumentsatroomandbodytemperatures