{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T03:30:22Z","timestamp":1772163022644,"version":"3.50.1"},"reference-count":34,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2023,3,11]],"date-time":"2023-03-11T00:00:00Z","timestamp":1678492800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Mohammed Bin Rashid University of Medicine and Health Sciences","award":["RG2019-5"],"award-info":[{"award-number":["RG2019-5"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>This study aimed to assess the effect of mechanical loading and heating on the cyclic fatigue and torsional fracture resistances of heat-treated nickel\u2013titanium files after usage and autoclaving. Sixty files (One Curve) were tested for cyclic fatigue and torsional fracture resistances using customized devices. The files were divided into three groups according to the test conditions (n = 10); new (group-N), used for simulated canal shaping (group-U), and sterilized after use (group-S). For cyclic fatigue resistances, the files were freely rotated in a curved metal canal under body temperature; the time elapsed to fracture was recorded and the numbers of cycles to fracture (NCF) were calculated. For the torsional resistances, the file tip was fixed and rotated until the file fractured. The maximum torsional load and distortion angle were recorded. The toughness was calculated. Fracture fragments were examined with a scanning electron microscope. Data were analyzed using a one-way analysis of variance and Tukey\u2019s post hoc test at the significance level of 95%. Group-U showed significantly higher NCF than group-S (p &lt; 0.05). However, there was no significant differences between groups-N and -S in the NCF (p &gt; 0.05). Group-N showed a significantly bigger distortional angle and higher torsional toughness than groups-U and -S, but the ultimate torsional strength did not have significant difference between the groups. Under the limitation of this study, autoclave sterilization after single-usage did not improve the fracture resistance of heat-treated One Curve nickel\u2013titanium files.<\/jats:p>","DOI":"10.3390\/ma16062261","type":"journal-article","created":{"date-parts":[[2023,3,13]],"date-time":"2023-03-13T03:03:57Z","timestamp":1678676637000},"page":"2261","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Effect from Autoclave Sterilization and Usage on the Fracture Resistance of Heat-Treated Nickel\u2013Titanium Rotary Files"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5339-0362","authenticated-orcid":false,"given":"Rashid","family":"El Abed","sequence":"first","affiliation":[{"name":"Endodontic Department, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai 505055, United Arab Emirates"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7122-0196","authenticated-orcid":false,"given":"Dana","family":"Al Raeesi","sequence":"additional","affiliation":[{"name":"Endodontic Department, Emirates Health Services Establishment, Dubai, United Arab Emirates"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aisha","family":"Alshehhi","sequence":"additional","affiliation":[{"name":"Endodontic Department, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai 505055, United Arab Emirates"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zuhair","family":"Alkhatib","sequence":"additional","affiliation":[{"name":"Endodontic Department, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai 505055, United Arab Emirates"},{"name":"Emirates Endodontic Society, Dubai, United Arab Emirates"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8518-3066","authenticated-orcid":false,"given":"Amar H.","family":"Khamis","sequence":"additional","affiliation":[{"name":"Biostatistics Department, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai 505055, United Arab Emirates"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5865-7943","authenticated-orcid":false,"given":"Mohamed","family":"Jamal","sequence":"additional","affiliation":[{"name":"Endodontic Department, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai 505055, United Arab Emirates"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8032-1194","authenticated-orcid":false,"given":"Hyeon-Cheol","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Conservative Dentistry, School of Dentistry, Dental Research Institute, Pusan National University, Yangsan 50612, Republic of Korea"},{"name":"Dental and Life Science Institute, Pusan National University, Yangsan 50612, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e67","DOI":"10.1590\/1807-3107bor-2018.vol32.0067","article-title":"Nickel-titanium instruments in endodontics: A concise review of the state of the art","volume":"32","author":"Gavini","year":"2018","journal-title":"Braz. 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