Biomechanical evaluation of three full-arch immediate loading protocols in the mandible via finite element analysis: All-on-4, Trefoil, and Five-implant design

Biomechanical evaluation of three full-arch immediate loading protocols in the mandible via finite element analysis: All-on-4, Trefoil, and Five-implant design | 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 Biomechanical evaluation of three full-arch immediate loading protocols in the mandible via finite element analysis: All-on-4, Trefoil, and Five-implant design Nagehan BAKİ, Güler YILDIRIM AVCU, Mesut TUZLALI This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7564986/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 27 Nov, 2025 Read the published version in BMC Oral Health → Version 1 posted 8 You are reading this latest preprint version Abstract Background: Edentulism in the mandible poses major functional and biomechanical challenges, as conventional dentures often fail to provide stability due to progressive bone resorption. Immediate loading full-arch implant protocols such as All-on-4, Trefoil, and Five-Implant designs have been developed to improve masticatory efficiency and long-term outcomes. Finite element analysis (FEA) enables the biomechanical assessment of these approaches by simulating stress, strain, and deformation under functional loads. This study aimed to biomechanically compare three immediate loading full-arch rehabilitation protocols—Trefoil, All-on-4, and 5-Implant designs—in the edentulous mandible using three-dimensional finite element analysis (FEA), focusing on stress distribution, strain accumulation, and deformation patterns under functional loading. Materials and Methods: A digital edentulous mandible model was constructed, incorporating cortical and cancellous bone layers, and standardized prosthetic designs for each configuration. Three implant-supported protocols were simulated: Trefoil (three axial implants with a prefabricated bar), All-on-4 (two axial anterior and two posterior tilted implants), and a Five-Implant design (implants at midline, canine, and second premolar positions). The implant–bone interface, simulating immediate loading without full osseointegration, was assigned a coefficient of 0.30. A 100 N axial and oblique load was applied to the first molar's central fossa. Stress distribution, equivalent strain, and deformation across these three treatment modalities were analyzed using FEA software. Results: The Five-Implant model exhibited the most favorable biomechanical outcomes, demonstrating the lowest stress and strain values across prosthesis, implant components, and cortical bone. The Trefoil system showed the highest prosthetic stress (156.48 MPa axial; 119.32 MPa oblique) and abutment screw deformation, attributed to its reduced implant support and increased cantilever length. The All-on-4 configuration generated elevated cortical bone strain under oblique loading (4180 με), surpassing the pathological overload threshold (>4000 με). In contrast, the Five-Implant model maintained cortical strain within the physiological remodeling range across all loading scenarios. Conclusion: Implant number and distribution significantly affect biomechanical behavior in full-arch immediate loading protocols. While the Five-Implant design offers biomechanical superiority in stress mitigation and bone preservation, Trefoil and All-on-4 configurations present design-dependent biomechanical challenges. Individualized treatment planning considering anatomical limitations and functional loading conditions is essential to optimize clinical outcomes. Trefoil All-on-4 5-implant design dental implant finite element analysis immediate loading Full Text Additional Declarations No competing interests reported. Supplementary Files videos.rar Cite Share Download PDF Status: Published Journal Publication published 27 Nov, 2025 Read the published version in BMC Oral Health → Version 1 posted Editorial decision: Revision requested 05 Nov, 2025 Reviews received at journal 05 Nov, 2025 Reviews received at journal 26 Oct, 2025 Reviewers agreed at journal 26 Oct, 2025 Reviewers agreed at journal 22 Oct, 2025 Reviewers invited by journal 22 Oct, 2025 Submission checks completed at journal 22 Oct, 2025 First submitted to journal 02 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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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-7564986","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":523977834,"identity":"6e776974-bdd0-4ffd-892b-156477b04ceb","order_by":0,"name":"Nagehan 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design","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"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 Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Trefoil, All-on-4, 5-implant design, dental implant, finite element analysis, immediate loading","lastPublishedDoi":"10.21203/rs.3.rs-7564986/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7564986/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eEdentulism in the mandible poses major functional and biomechanical challenges, as conventional dentures often fail to provide stability due to progressive bone resorption. Immediate loading full-arch implant protocols such as All-on-4, Trefoil, and Five-Implant designs have been developed to improve masticatory efficiency and long-term outcomes. Finite element analysis (FEA) enables the biomechanical assessment of these approaches by simulating stress, strain, and deformation under functional loads.\u003c/p\u003e\n\u003cp\u003eThis study aimed to biomechanically compare three immediate loading full-arch rehabilitation protocols—Trefoil, All-on-4, and 5-Implant designs—in the edentulous mandible using three-dimensional finite element analysis (FEA), focusing on stress distribution, strain accumulation, and deformation patterns under functional loading.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and Methods: \u003c/strong\u003eA digital edentulous mandible model was constructed, incorporating cortical and cancellous bone layers, and standardized prosthetic designs for each configuration. Three implant-supported protocols were simulated: Trefoil (three axial implants with a prefabricated bar), All-on-4 (two axial anterior and two posterior tilted implants), and a Five-Implant design (implants at midline, canine, and second premolar positions). The implant–bone interface, simulating immediate loading without full osseointegration, was assigned a coefficient of 0.30. A 100 N axial and oblique load was applied to the first molar's central fossa. Stress distribution, equivalent strain, and deformation across these three treatment modalities were analyzed using FEA software.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eThe Five-Implant model exhibited the most favorable biomechanical outcomes, demonstrating the lowest stress and strain values across prosthesis, implant components, and cortical bone. The Trefoil system showed the highest prosthetic stress (156.48 MPa axial; 119.32 MPa oblique) and abutment screw deformation, attributed to its reduced implant support and increased cantilever length. The All-on-4 configuration generated elevated cortical bone strain under oblique loading (4180 με), surpassing the pathological overload threshold (\u0026gt;4000 με). In contrast, the Five-Implant model maintained cortical strain within the physiological remodeling range across all loading scenarios.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion: \u003c/strong\u003eImplant number and distribution significantly affect biomechanical behavior in full-arch immediate loading protocols. While the Five-Implant design offers biomechanical superiority in stress mitigation and bone preservation, Trefoil and All-on-4 configurations present design-dependent biomechanical challenges. Individualized treatment planning considering anatomical limitations and functional loading conditions is essential to optimize clinical outcomes.\u003c/p\u003e","manuscriptTitle":"Biomechanical evaluation of three full-arch immediate loading protocols in the mandible via finite element analysis: All-on-4, Trefoil, and Five-implant design","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-07 14:36:39","doi":"10.21203/rs.3.rs-7564986/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-11-05T17:44:33+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-05T13:52:31+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-26T08:02:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"66675667423389467279473861821262333146","date":"2025-10-26T08:01:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"126800563354574931721428169385918881475","date":"2025-10-22T06:36:32+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-22T06:06:22+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-22T05:01:56+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Oral Health","date":"2025-10-02T22:22:00+00:00","index":"","fulltext":""}],"status":"published","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 Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"8f37e514-f088-42c4-ae7c-d90a8ff4ac63","owner":[],"postedDate":"October 7th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-12-01T16:10:45+00:00","versionOfRecord":{"articleIdentity":"rs-7564986","link":"https://doi.org/10.1186/s12903-025-07404-1","journal":{"identity":"bmc-oral-health","isVorOnly":false,"title":"BMC Oral Health"},"publishedOn":"2025-11-27 15:58:07","publishedOnDateReadable":"November 27th, 2025"},"versionCreatedAt":"2025-10-07 14:36:39","video":"","vorDoi":"10.1186/s12903-025-07404-1","vorDoiUrl":"https://doi.org/10.1186/s12903-025-07404-1","workflowStages":[]},"version":"v1","identity":"rs-7564986","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7564986","identity":"rs-7564986","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}