Comparative Study on Cyclic Fatigue Resistance of Two Series of Rotary Instruments: Austenitic NiTi versus Thermally Treated NiTi Alloys (Gold, Blue, and Pink)

Comparative Study on Cyclic Fatigue Resistance of Two Series of Rotary Instruments: Austenitic NiTi versus Thermally Treated NiTi Alloys (Gold, Blue, and Pink) | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Comparative Study on Cyclic Fatigue Resistance of Two Series of Rotary Instruments: Austenitic NiTi versus Thermally Treated NiTi Alloys (Gold, Blue, and Pink) Antonio Libonati, Danilo Marroni, Giulio Barbalace, Francesco Campanella, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7900550/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 18 You are reading this latest preprint version Abstract Objectives: Evaluate the fracture-free cutting efficiency of different NiTi alloys by testing Mtwo (Sweden & Martina) and BlueShaper Pro (Zarc4endo) endodontic instruments for cyclic fatigue strength and length of separated fragments. Materials and methos: The study examined a sample of 160 files, all of the same length, used at the manufacturer-recommended speed and torque in continuous rotation. The files were tested in custom-designed curved artificial canal made of stainless steel, operated by an endodontic motor fixed in place to prevent axial movement. The experiment was conducted at a constant, continuously monitored temperature. The number of cycles to failure (NFC) was recorded with a stopwatch, and the lengths of the separated fragments (FL) were measured using a digital caliper. To identify statistically significant differences between groups, a P-value of < 0.05 was considered. Results: In the first two comparisons, the austenitic alloy Mtwo demonstrated better cyclic fatigue resistance with higher NFC values (p < 0.05). In the second and third comparisons, the heat-treated martensitic alloy BleuShaper Pro showed higher NFCs than the austenitic alloy at the chosen experimental standards (p < 0.05). Conclusions: No endodontic instrument is completely immune to separation at the point of maximum stress; however, some tools offer superior strength (NFC) in relation to cross-section, taper, and alloy. Clinical relevance: The results obtained in this study suggest that the use of endodontic instrument series composed of both austenitic and martensitic alloys represents a gold standard in clinical practice. Cyclic fatigue modified NiTi alloys BlueShaper Pro Mtwo Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 03 May, 2026 Reviews received at journal 24 Mar, 2026 Reviews received at journal 22 Mar, 2026 Reviews received at journal 22 Mar, 2026 Reviewers agreed at journal 14 Mar, 2026 Reviews received at journal 14 Mar, 2026 Reviewers agreed at journal 13 Mar, 2026 Reviewers agreed at journal 13 Mar, 2026 Reviewers agreed at journal 11 Mar, 2026 Reviews received at journal 10 Mar, 2026 Reviewers agreed at journal 09 Mar, 2026 Reviewers agreed at journal 07 Mar, 2026 Reviewers agreed at journal 06 Mar, 2026 Reviewers invited by journal 06 Mar, 2026 Editor invited by journal 04 Feb, 2026 Editor assigned by journal 14 Nov, 2025 Submission checks completed at journal 14 Nov, 2025 First submitted to journal 19 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7900550","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":603685025,"identity":"40ca4fbe-79e9-4bde-8de2-d734fba80981","order_by":0,"name":"Antonio Libonati","email":"","orcid":"","institution":"Catholic University of Our Lady of Good Counsel","correspondingAuthor":false,"prefix":"","firstName":"Antonio","middleName":"","lastName":"Libonati","suffix":""},{"id":603685028,"identity":"1d2be570-0e6f-4b0a-9b5a-36cbc6169c44","order_by":1,"name":"Danilo Marroni","email":"","orcid":"","institution":"University of Rome Tor 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Pink)","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-oral-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ohea","sideBox":"Learn more about [BMC Oral Health](http://bmcoralhealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/ohea/default.aspx","title":"BMC Oral Health","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC 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The files were tested in custom-designed curved artificial canal made of stainless steel, operated by an endodontic motor fixed in place to prevent axial movement. The experiment was conducted at a constant, continuously monitored temperature. The number of cycles to failure (NFC) was recorded with a stopwatch, and the lengths of the separated fragments (FL) were measured using a digital caliper. To identify statistically significant differences between groups, a P-value of \u0026lt; 0.05 was considered.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eResults: \u003c/strong\u003e\u003c/em\u003e\u003cem\u003eIn the first two comparisons, the austenitic alloy Mtwo demonstrated better cyclic fatigue resistance with higher NFC values (p \u0026lt; 0.05). 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