Management of a Fractured Narrow-Diameter Dental Implant from All-on-eight Overdenture : A Case Report

Management of a Fractured Narrow-Diameter Dental Implant from All-on-eight Overdenture : A Case Report | 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 Case Report Management of a Fractured Narrow-Diameter Dental Implant from All-on-eight Overdenture : A Case Report Mouni Damineni, Richa Singhania This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7133461/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: Fracture of narrow-diameter dental implants (NDIs), although uncommon, presents unique challenges and can jeopardize prosthetic stability and long-term treatment success. When a fractured implant from a full-arch overdenture is supported by several implants, management is especially challenging. Case Presentation: This case report describes the diagnosis and surgical treatment of a broken NDI placed in a patient rehabilitated six years ago on a maxillary all-on-eight implant-retained overdenture. Clinical and radiologically based assessments confirmed a horizontal fracture in the middle third of the implant body. Implant extraction was managed by conservative extraction of the coronal portion followed by surgical excision of the apical region by trephination using radiographic imaging. The site was managed later on for potential implant placement and prosthetic re-stabilization. Conclusion: This case highlights surgical techniques and guiding principles related to the treatment of broken NDIs and relevant decision-making criteria. In order to optimize positive outcomes in complex full-arch implant procedures, the knowledge of biomechanical limitations, careful design, and appropriate retrieval approaches play a vital role. Fractured Implant Implant Management Implant overdenture Narrow-diameter Implant Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Narrow-diameter implants (NDIs), typically defined as implants with a diameter of ≤ 3.5 mm 1 . NDIs offer a valuable alternative to extensive augmentation procedures such as guided bone regeneration, block grafting, or ridge-splitting techniques where bone density is usually poor and resorption more evident 2 . Their application in full-arch prosthetic rehabilitation—particularly implant-retained overdentures—has demonstrated encouraging clinical outcomes with respect to patient comfort, satisfaction, and function 3 . Tagger-Green et al. identify several contributing factors to implant fracture, including biomechanical overload, implant diameter and location, parafunctional activity, prosthetic misfit, and material fatigue 4 . The diminished cross-sectional strength of Narrow-diameter implants are inherently more susceptible to fractures. Additionally, late implant failures may result from overload-related fatigue, peri-implant bone loss, and the cumulative effects of prosthetic and biomechanical factors as described by Goodacre et al. and Albrektsson et al. 5 – 8 . Once a fracture is diagnosed, the management of the remaining implant fragments can be complex—particularly when only part of the implant is clinically accessible. In such cases, preservation of surrounding bone is critical to allow for future site rehabilitation. This case report presents a single NDI fracture within a maxillary All-on-Eight overdenture entirely supported by narrow-diameter implants. Despite initial stability and functionality, mechanical failure of one implant after six years necessitated comprehensive evaluation and surgical intervention. This case underlines the importance of load distribution, prosthetic design, and implant selection in multi-unit restorations involving narrow-diameter implant supported maxillary overdenture. Moreover, this case report provides a cumulative approach for implant extraction and implant site management conservatively, therefore providing significant clinical insights on the long-term risk factors for NDI-based full-arch prosthesis. Case Presentation In February 2025, A 40-year-old male patient presented with a complaint of mobility of implant and discomfort localized to the right maxillary canine region of his maxillary overdenture. The patient had undergone a full-arch maxillary rehabilitation in March 2018 at another dental clinic, where eight narrow diameter implants (NDIs) were placed and restored with unsplinted ball attachments supporting a removable overdenture. In late 2024, He went to another clinic,The appropriate size/fit of the o-rings were not identified, so the universal rings were placed. He was also suggested to change the o-rings on ball attachments periodically. After changing o-rings, the patient reported that he heard a snap and felt tenderness in the upper right implant and was not able to take the dentures out. After a few days of changing o-rings, the patient forced the overdenture out and was able to place it back in the mouth. He still had discomfort and tenderness but could not get any permanent solution. Then he came to our clinic for further evaluation and treatment. At the time of presentation, the patient reported progressive mobility and soreness in the overdenture over the past few months. Clinical examination revealed significant mobility of the implant in the canine area, along with peri-implant mucosal erythema, inflammation, and tenderness during function. The overdenture itself was intact, with no signs of fracture or instability. Periapical radiography revealed a horizontal fracture in the coronal third of the implant body. The implant system, diameter, and exact placement protocol could not be identified, as no surgical records, restorative details, or manufacturer documentation were available from the referring office. The remaining seven implants appeared clinically stable and asymptomatic, with no signs of peri-implantitis or mechanical failure. Clinical and Radiographic Findings : Clinical examination revealed gingival inflammation and tenderness in the area. Radiographic assessment (periapical, panoramic radiographs, and CBCT imaging) showed a horizontally fractured narrow-diameter implant with the fracture line located approximately at the middle third of implant body. The coronal segment of the implant was mobile. Management : Following the diagnosis of implant fracture at the #6 position, clinical and radiographic assessments confirmed that the fractured implant segment was still osseointegrated apically, with slight tenderness on palpation but no significant periapical pathology. Bone loss was noted around the coronal third of the implant body. Surgical intervention was done to remove the fractured implant under the local anesthesia, which was the source of pain. The coronal half of the fractured implant was carefully removed using a counter-torque ratchet device. The apical portion remained embedded and was not retrievable via conservative means. To retrieve the apical fragment, a surgical approach was undertaken: A full-thickness mucoperiosteal flap was elevated to expose the implant site. Using a surgical handpiece, bone was carefully drilled circumferentially around the retained apical fragment with a trephine bur under copious irrigation. A slight notch was made in the implant to provide the purchase point. Once adequate bone removal allowed access, the remaining fragment was mobilized and extracted with elevators and fine surgical forceps. Hemostasis was achieved, and the site was thoroughly debrided. Allograft graft was placed followed by GTR membrane. The flap was repositioned and sutured using chromic gut sutures. Outcome and Follow-Up : Postoperative healing was uneventful. The patient was prescribed a 7-day course of antibiotics and instructed on proper oral hygiene. The patient was advised on bone grafting and delayed implant placement after sufficient healing and site evaluation. The site was then allowed to heal without immediate replacement due to patient preference and adequate support from the remaining seven implants for maxillary overdenture. The acrylic overdenture was modified to accommodate the absence of the #6 implant. A chairside reline was performed to optimize tissue adaptation and stability. Occlusion was re-evaluated and adjusted to reduce lateral forces, particularly in the canine region, and the patient was advised on parafunctional habit awareness and removal of denture during sleep. Follow-up at 1 week and 1 month showed satisfactory healing with no signs of infection or inflammation and the prosthesis remained stable and functional. The patient reported no discomfort, and the remaining implants showed no signs of mobility or bone loss. Radiographs confirmed continued osseointegration and favorable bone levels around the remaining implants. Discussion The fracture of regular implants have been discussed, but with a narrow diameter implant have not been reported often. Fracture of narrow-diameter implants poses diagnostic as well as treatment challenges. A two-stage approach with initial conservative retrieval followed by the surgical intervention to remove the remaining structure, allows controlled removal while minimizing the bone loss. Mendonca et al described the conservative treatment leaving the lower part of the implant 9 . Balshi et al earlier presented cutting and refacing the implant with thread of screw and placing a longer connector with the prosthesis modifications 10 . The use of a trephine bur to create a notch to get the purchase point offers a predictable method for removing retained implant segments, though it requires careful planning to preserve bone for future implants as any other methods. This case highlights the importance of firstly and most importantly the diagnosis of fractured implant, appropriate implant diameter selection, prosthetic planning, and timely intervention when complications arise 11 . Also, consider the treatment planning when you should try to restore the implants or change the rings, or abutments. While implant fractures are a relatively rare complication in implant dentistry 6 , 10 , 12 , 13 , they pose significant clinical challenges, often requiring surgical removal and prosthetic modification. In this case, a single narrow diameter implant placed at the maxillary right canine fractured six years after loading as part of an All-on-8 maxillary acrylic overdenture. For several years, the implant-supported prosthesis had performed without complications, underscoring the delayed but crucial nature of mechanical failure in long-term follow-up and using appropriate o-rings. Particularly in cases when alveolar ridge width is compromised or patients want to avoid grafting procedures, the use of narrow diameter implants (NDIs) has grown more common. Although NDIs have proven great survival rates in various applications, including overdentures, their smaller cross-sectional thickness naturally increases mechanical failure risk, especially under extended or concentrated occlusal load. In addition, using poorly fitted o-rings over ball attachments further accentuated the implant fracture. The fracture at the maxillary canine region likely resulted from a combination of long-term functional loading and biomechanical factors such as: Stress concentration in the canine region , which often acts as a key support point in overdenture designs Fatigue over time , particularly given the six-year duration of loading Possible uneven load distribution , especially if the overdenture experienced slight misfit or if occlusion was not periodically adjusted Material limits of narrow diameter implants , which are more susceptible to bending and fatigue-related fractures in high-stress areas Use of poorly fitted o-rings , where overdenture was not seated properly resulting in overload on one implant causing fracture. Although eight implants were utilized to support the maxillary overdenture, which theoretically increases load sharing, this case shows that a greater number of implants may not totally lower the risk of fracture when all implants are of reduced diameter. Particularly in prosthetic stability and lateral load resistance, the canine area is rather important; so, a compromised implant in this place would greatly influence the prosthetic function. Prosthetic design might have also added to the problem. Using an acrylic overdenture instead of a more solid metal-reinforced construction or erroneous fit can allow micro-movements and stress transfer straight to the implants, hence increasing strain over time. Further aggravating mechanical stress would be opposing dentition, patient-specific habits like bruxism or clenching, and a missing splinted framework. This case underlines the need of long-term monitoring and maintenance in full-arch NDI-supported rehabilitations. Such problems may be avoided by regular occlusal examinations, early recognition of wear or stress-related changes, and consideration of reinforcing or changing the prosthesis design gradually. Future treatment approaches may benefit from selectively using wider-diameter implants in important load-bearing areas like the canines. Conclusion The possibility of late-stage mechanical difficulties in full-arch maxillary overdentures supported by narrow diameter implants(NDI) was highlighted in this case report. The fracture of a single NDI at the canine position highlights the combined effect of mechanical stress, the use of poorly fitted o-rings on ball attachments, and the biomechanical constraints related with reduced implant diameter despite a favorable six-year period of uneventful and satisfactory implant and prosthetic function . Optimizing long-term outcomes necessitates meticulous planning, which includes the strategic placement of wider implants in high-load areas whenever feasible, regular prosthetic maintenance, and patient education on parafunctional habits. In full-arch restorations that exclusively rely on narrow diameter implants, clinicians should maintain a high level of vigilance regarding long-term follow-up. Even a single implant failure can have a significant impact on patient satisfaction and prosthetic performance. Abbreviations NDI Narrow Diameter Implants Declarations Consent for publication: Written informed consent was obtained from the patient for the publication of this case report and accompanying images. Funding: No funding for this case report. Clinical trial number: Not applicable Ethics approval and consent to participate: This case report involves no intervention beyond standard clinical care. No ethical approval was obtained. Written consent was obtained from the patient for treatment and inclusion in this report. Availability of data and materials: Data sharing is not applicable to this article as no datasets were generated or analysed during the current study. Competing interest: No competing interests Conflict of interest: The authors declare no conflict of interest directly or indirectly with any organization or products. Acknowledgements: The authors would like to thank Dr. Dale Kunkel and clinical staff of Four States Dental Care for their assistance with patient care and documentation. Author Contributions: M.D performed the surgery, collected data and drafted manuscript. R.S assisted with surgery and revised the manuscript. All authors have viewed the manuscript and accepted the submission. References Schiegnitz E, Al‐Nawas B. Narrow‐diameter implants: A systematic review and meta‐analysis. Clin Oral Implants Res . 2018;29(S16):21-40. doi:10.1111/clr.13272 Preoteasa E, Imre M, Lerner H, Tancu AM, Preoteasa CT. Narrow Diameter and Mini Dental Implant Overdentures. In: Virdi MS, ed. Emerging Trends in Oral Health Sciences and Dentistry . InTech; 2015. doi:10.5772/59514 Storelli S, Caputo A, Palandrani G, et al. Use of Narrow‐Diameter Implants in Completely Edentulous Patients as a Prosthetic Option: A Systematic Review of the Literature. Brizuela-Velasco A, ed. BioMed Res Int . 2021;2021(1):5571793. doi:10.1155/2021/5571793 Tagger Green N, Machtei EE, Horwitz J, Peled M. Fracture of Dental Implants: Literature Review and Report of a Case: Implant Dent . 2002;11(2):137-143. doi:10.1097/00008505-200204000-00014 Albrektsson T, Zarb G, Worthington P, Eriksson AR. The long-term efficacy of currently used dental implants: a review and proposed criteria of success. Int J Oral Maxillofac Implants . 1986;1(1):11-25. Goodacre CJ, Kan JYK, Rungcharassaeng K. Clinical complications of osseointegrated implants. J Prosthet Dent . 1999;81(5):537-552. doi:10.1016/S0022-3913(99)70208-8 Misch CE. Consideration of biomechanical stress in treatment with dental implants. Dent Today . 2006;25(5):80, 82, 84-85; quiz 85. Rangert B, Krogh PH, Langer B, Van Roekel N. Bending overload and implant fracture: a retrospective clinical analysis. Int J Oral Maxillofac Implants . 1995;10(3):326-334. Mendonça G, Silveira Mendonça DB, Fernandes-Neto AJ, Neves FD. Management of Fractured Dental Implants: A Case Report. Implant Dent . 2009;18(1):10-16. doi:10.1097/ID.0b013e318192cafe Balshi TJ. An analysis and management of fractured implants: a clinical report. Int J Oral Maxillofac Implants . 1996;11(5):660-666. Velásquez-Plata D, Lutonsky J, Oshida Y, Jones R. A close-up look at an implant fracture: a case report. Int J Periodontics Restorative Dent . 2002;22(5):483-491. Adell R, Eriksson B, Lekholm U, Brånemark PI, Jemt T. Long-term follow-up study of osseointegrated implants in the treatment of totally edentulous jaws. Int J Oral Maxillofac Implants . 1990;5(4):347-359. Eckert SE, Meraw SJ, Cal E, Ow RK. Analysis of incidence and associated factors with fractured implants: a retrospective study. Int J Oral Maxillofac Implants . 2000;15(5):662-667. 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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-7133461","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":493924036,"identity":"fda9f11d-23bd-47a0-bd9d-f45a7c923ccc","order_by":0,"name":"Mouni 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18:53:09","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7133461/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7133461/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":88408558,"identity":"5052b5b8-1d5c-401e-91dd-36b38be55be2","added_by":"auto","created_at":"2025-08-06 08:13:14","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":138892,"visible":true,"origin":"","legend":"\u003cp\u003ea) Panoramic radiograph showing the all-on-8 implants for the overdenture\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7133461/v1/ddf5cbcdf58e7b3e7e6a07dd.jpg"},{"id":88408556,"identity":"aa7d9bc8-395a-4391-801a-27fb289a32b1","added_by":"auto","created_at":"2025-08-06 08:13:14","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":86112,"visible":true,"origin":"","legend":"\u003cp\u003ea) Periapical image showing the horizontal fracture of the narrow diameter implant\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7133461/v1/6901c6f044300a5d41fd7a7d.jpg"},{"id":88409861,"identity":"0641f2ac-7226-4cc6-b0c6-6e0f79467e09","added_by":"auto","created_at":"2025-08-06 08:21:14","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":41955,"visible":true,"origin":"","legend":"\u003cp\u003ea) Cross sectional image of the fractured implant by CBCT\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7133461/v1/0ac22af1e35916296e7f22b7.jpg"},{"id":88409862,"identity":"401fa00c-3ace-4013-b9ba-a219a833fa32","added_by":"auto","created_at":"2025-08-06 08:21:14","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":71978,"visible":true,"origin":"","legend":"\u003cp\u003ea) The apical segment of implant remaining\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7133461/v1/2dd9ed7e3f627ec39b63acfa.jpg"},{"id":88408565,"identity":"4208731b-3214-4ba7-bcff-0756d566cab0","added_by":"auto","created_at":"2025-08-06 08:13:14","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":91967,"visible":true,"origin":"","legend":"\u003cp\u003ea) Radiograph showing troughing around the implant for its retrieval\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7133461/v1/b9dfda8920eefc6ddbab1605.jpg"},{"id":92684479,"identity":"5ddd7567-02f3-4ef3-8830-40a7dea9c639","added_by":"auto","created_at":"2025-10-03 02:31:37","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":903572,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7133461/v1/e0a72581-9fdc-4873-bc5b-6a49e8529faf.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Management of a Fractured Narrow-Diameter Dental Implant from All-on-eight Overdenture : A Case Report","fulltext":[{"header":"Introduction","content":"\u003cp\u003eNarrow-diameter implants (NDIs), typically defined as implants with a diameter of ≤ 3.5 mm\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. NDIs offer a valuable alternative to extensive augmentation procedures such as guided bone regeneration, block grafting, or ridge-splitting techniques where bone density is usually poor and resorption more evident \u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. Their application in full-arch prosthetic rehabilitation—particularly implant-retained overdentures—has demonstrated encouraging clinical outcomes with respect to patient comfort, satisfaction, and function\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eTagger-Green et al. identify several contributing factors to implant fracture, including biomechanical overload, implant diameter and location, parafunctional activity, prosthetic misfit, and material fatigue \u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. The diminished cross-sectional strength of Narrow-diameter implants are inherently more susceptible to fractures. Additionally, late implant failures may result from overload-related fatigue, peri-implant bone loss, and the cumulative effects of prosthetic and biomechanical factors as described by Goodacre et al. and Albrektsson et al.\u003csup\u003e\u003cspan additionalcitationids=\"CR6 CR7\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e–\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eOnce a fracture is diagnosed, the management of the remaining implant fragments can be complex—particularly when only part of the implant is clinically accessible. In such cases, preservation of surrounding bone is critical to allow for future site rehabilitation. This case report presents a single NDI fracture within a maxillary All-on-Eight overdenture entirely supported by narrow-diameter implants. Despite initial stability and functionality, mechanical failure of one implant after six years necessitated comprehensive evaluation and surgical intervention.\u003c/p\u003e\u003cp\u003eThis case underlines the importance of load distribution, prosthetic design, and implant selection in multi-unit restorations involving narrow-diameter implant supported maxillary overdenture. Moreover, this case report provides a cumulative approach for implant extraction and implant site management conservatively, therefore providing significant clinical insights on the long-term risk factors for NDI-based full-arch prosthesis.\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003eIn February 2025, A 40-year-old male patient presented with a complaint of mobility of implant and discomfort localized to the right maxillary canine region of his maxillary overdenture. The patient had undergone a full-arch maxillary rehabilitation in March 2018 at another dental clinic, where eight narrow diameter implants (NDIs) were placed and restored with unsplinted ball attachments supporting a removable overdenture.\u003c/p\u003e\u003cp\u003eIn late 2024, He went to another clinic,The appropriate size/fit of the o-rings were not identified, so the universal rings were placed. He was also suggested to change the o-rings on ball attachments periodically. After changing o-rings, the patient reported that he heard a snap and felt tenderness in the upper right implant and was not able to take the dentures out. After a few days of changing o-rings, the patient forced the overdenture out and was able to place it back in the mouth. He still had discomfort and tenderness but could not get any permanent solution. Then he came to our clinic for further evaluation and treatment.\u003c/p\u003e\u003cp\u003eAt the time of presentation, the patient reported progressive mobility and soreness in the overdenture over the past few months. Clinical examination revealed significant mobility of the implant in the canine area, along with peri-implant mucosal erythema, inflammation, and tenderness during function. The overdenture itself was intact, with no signs of fracture or instability.\u003c/p\u003e\u003cp\u003ePeriapical radiography revealed a horizontal fracture in the coronal third of the implant body. The implant system, diameter, and exact placement protocol could not be identified, as no surgical records, restorative details, or manufacturer documentation were available from the referring office. The remaining seven implants appeared clinically stable and asymptomatic, with no signs of peri-implantitis or mechanical failure.\u003c/p\u003e\u003cp\u003e\u003cb\u003eClinical and Radiographic Findings\u003c/b\u003e:\u003c/p\u003e\u003cp\u003eClinical examination revealed gingival inflammation and tenderness in the area. Radiographic assessment (periapical, panoramic radiographs, and CBCT imaging) showed a horizontally fractured narrow-diameter implant with the fracture line located approximately at the middle third of implant body. The coronal segment of the implant was mobile.\u003c/p\u003e\u003cp\u003e\u003cb\u003eManagement\u003c/b\u003e:\u003c/p\u003e\u003cp\u003eFollowing the diagnosis of implant fracture at the #6 position, clinical and radiographic assessments confirmed that the fractured implant segment was still osseointegrated apically, with slight tenderness on palpation but no significant periapical pathology. Bone loss was noted around the coronal third of the implant body. Surgical intervention was done to remove the fractured implant under the local anesthesia, which was the source of pain. The coronal half of the fractured implant was carefully removed using a counter-torque ratchet device. The apical portion remained embedded and was not retrievable via conservative means.\u003c/p\u003e\u003cp\u003eTo retrieve the apical fragment, a surgical approach was undertaken:\u003c/p\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eA full-thickness mucoperiosteal flap was elevated to expose the implant site.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eUsing a surgical handpiece, bone was carefully drilled circumferentially around the retained apical fragment with a trephine bur under copious irrigation. A slight notch was made in the implant to provide the purchase point.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eOnce adequate bone removal allowed access, the remaining fragment was mobilized and extracted with elevators and fine surgical forceps.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003cp\u003eHemostasis was achieved, and the site was thoroughly debrided. Allograft graft was placed followed by GTR membrane. The flap was repositioned and sutured using chromic gut sutures.\u003c/p\u003e\u003cp\u003e\u003cb\u003eOutcome and Follow-Up\u003c/b\u003e:\u003c/p\u003e\u003cp\u003ePostoperative healing was uneventful. The patient was prescribed a 7-day course of antibiotics and instructed on proper oral hygiene. The patient was advised on bone grafting and delayed implant placement after sufficient healing and site evaluation.\u003c/p\u003e\u003cp\u003eThe site was then allowed to heal without immediate replacement due to patient preference and adequate support from the remaining seven implants for maxillary overdenture. The acrylic overdenture was modified to accommodate the absence of the #6 implant. A chairside reline was performed to optimize tissue adaptation and stability. Occlusion was re-evaluated and adjusted to reduce lateral forces, particularly in the canine region, and the patient was advised on parafunctional habit awareness and removal of denture during sleep.\u003c/p\u003e\u003cp\u003eFollow-up at 1 week and 1 month showed satisfactory healing with no signs of infection or inflammation and the prosthesis remained stable and functional. The patient reported no discomfort, and the remaining implants showed no signs of mobility or bone loss. Radiographs confirmed continued osseointegration and favorable bone levels around the remaining implants.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe fracture of regular implants have been discussed, but with a narrow diameter implant have not been reported often. Fracture of narrow-diameter implants poses diagnostic as well as treatment challenges. A two-stage approach with initial conservative retrieval followed by the surgical intervention to remove the remaining structure, allows controlled removal while minimizing the bone loss. Mendonca et al described the conservative treatment leaving the lower part of the implant \u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e. Balshi et al earlier presented cutting and refacing the implant with thread of screw and placing a longer connector with the prosthesis modifications\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. The use of a trephine bur to create a notch to get the purchase point offers a predictable method for removing retained implant segments, though it requires careful planning to preserve bone for future implants as any other methods.\u003c/p\u003e\u003cp\u003eThis case highlights the importance of firstly and most importantly the diagnosis of fractured implant, appropriate implant diameter selection, prosthetic planning, and timely intervention when complications arise\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. Also, consider the treatment planning when you should try to restore the implants or change the rings, or abutments.\u003c/p\u003e\u003cp\u003eWhile implant fractures are a relatively rare complication in implant dentistry\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e,\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e,\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e,\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e, they pose significant clinical challenges, often requiring surgical removal and prosthetic modification. In this case, a single narrow diameter implant placed at the maxillary right canine fractured six years after loading as part of an All-on-8 maxillary acrylic overdenture. For several years, the implant-supported prosthesis had performed without complications, underscoring the delayed but crucial nature of mechanical failure in long-term follow-up and using appropriate o-rings.\u003c/p\u003e\u003cp\u003eParticularly in cases when alveolar ridge width is compromised or patients want to avoid grafting procedures, the use of narrow diameter implants (NDIs) has grown more common. Although NDIs have proven great survival rates in various applications, including overdentures, their smaller cross-sectional thickness naturally increases mechanical failure risk, especially under extended or concentrated occlusal load. In addition, using poorly fitted o-rings over ball attachments further accentuated the implant fracture.\u003c/p\u003e\u003cp\u003eThe fracture at the maxillary canine region likely resulted from a combination of long-term functional loading and biomechanical factors such as:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eStress concentration in the canine region\u003c/b\u003e, which often acts as a key support point in overdenture designs\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eFatigue over time\u003c/b\u003e, particularly given the six-year duration of loading\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003ePossible uneven load distribution\u003c/b\u003e, especially if the overdenture experienced slight misfit or if occlusion was not periodically adjusted\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eMaterial limits of narrow diameter implants\u003c/b\u003e, which are more susceptible to bending and fatigue-related fractures in high-stress areas\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eUse of poorly fitted o-rings\u003c/b\u003e, where overdenture was not seated properly resulting in overload on one implant causing fracture.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eAlthough eight implants were utilized to support the maxillary overdenture, which theoretically increases load sharing, this case shows that a greater number of implants may not totally lower the risk of fracture when all implants are of reduced diameter. Particularly in prosthetic stability and lateral load resistance, the canine area is rather important; so, a compromised implant in this place would greatly influence the prosthetic function.\u003c/p\u003e\u003cp\u003eProsthetic design might have also added to the problem. Using an acrylic overdenture instead of a more solid metal-reinforced construction or erroneous fit can allow micro-movements and stress transfer straight to the implants, hence increasing strain over time. Further aggravating mechanical stress would be opposing dentition, patient-specific habits like bruxism or clenching, and a missing splinted framework.\u003c/p\u003e\u003cp\u003eThis case underlines the need of long-term monitoring and maintenance in full-arch NDI-supported rehabilitations. Such problems may be avoided by regular occlusal examinations, early recognition of wear or stress-related changes, and consideration of reinforcing or changing the prosthesis design gradually. Future treatment approaches may benefit from selectively using wider-diameter implants in important load-bearing areas like the canines.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe possibility of late-stage mechanical difficulties in full-arch maxillary overdentures supported by narrow diameter implants(NDI) was highlighted in this case report. The fracture of a single NDI at the canine position highlights the combined effect of mechanical stress, the use of poorly fitted o-rings on ball attachments, and the biomechanical constraints related with reduced implant diameter despite a favorable six-year period of uneventful and satisfactory implant and prosthetic function .\u003c/p\u003e\u003cp\u003eOptimizing long-term outcomes necessitates meticulous planning, which includes the strategic placement of wider implants in high-load areas whenever feasible, regular prosthetic maintenance, and patient education on parafunctional habits. In full-arch restorations that exclusively rely on narrow diameter implants, clinicians should maintain a high level of vigilance regarding long-term follow-up. Even a single implant failure can have a significant impact on patient satisfaction and prosthetic performance.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eNDI\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eNarrow Diameter Implants\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConsent for publication:\u0026nbsp;\u003c/strong\u003eWritten informed consent was obtained from the patient for the publication of this case report and accompanying images.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u0026nbsp;\u003c/strong\u003eNo funding for this case report.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial number:\u0026nbsp;\u003c/strong\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u0026nbsp;\u003c/strong\u003eThis case report involves no intervention beyond standard clinical care. No ethical approval was obtained. Written consent was obtained from the patient for treatment and inclusion in this report.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u0026nbsp;\u003c/strong\u003eData sharing is not applicable to this article as no datasets were generated or analysed during the current study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interest:\u0026nbsp;\u003c/strong\u003eNo competing interests\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest:\u0026nbsp;\u003c/strong\u003eThe authors declare no conflict of interest directly or indirectly with any organization or products.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u0026nbsp;\u003c/strong\u003eThe authors would like to thank Dr. Dale Kunkel and clinical staff of Four States Dental Care for their assistance with patient care and documentation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions:\u0026nbsp;\u003c/strong\u003eM.D performed the surgery, collected data and drafted manuscript. R.S assisted with surgery and revised the manuscript. All authors have viewed the manuscript and accepted the submission.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eSchiegnitz E, Al‐Nawas B. Narrow‐diameter implants: A systematic review and meta‐analysis. \u003cem\u003eClin Oral Implants Res\u003c/em\u003e. 2018;29(S16):21-40. doi:10.1111/clr.13272\u003c/li\u003e\n\u003cli\u003ePreoteasa E, Imre M, Lerner H, Tancu AM, Preoteasa CT. Narrow Diameter and Mini Dental Implant Overdentures. In: Virdi MS, ed. \u003cem\u003eEmerging Trends in Oral Health Sciences and Dentistry\u003c/em\u003e. InTech; 2015. doi:10.5772/59514\u003c/li\u003e\n\u003cli\u003eStorelli S, Caputo A, Palandrani G, et al. Use of Narrow‐Diameter Implants in Completely Edentulous Patients as a Prosthetic Option: A Systematic Review of the Literature. Brizuela-Velasco A, ed. \u003cem\u003eBioMed Res Int\u003c/em\u003e. 2021;2021(1):5571793. doi:10.1155/2021/5571793\u003c/li\u003e\n\u003cli\u003eTagger Green N, Machtei EE, Horwitz J, Peled M. Fracture of Dental Implants: Literature Review and Report of a Case: \u003cem\u003eImplant Dent\u003c/em\u003e. 2002;11(2):137-143. doi:10.1097/00008505-200204000-00014\u003c/li\u003e\n\u003cli\u003eAlbrektsson T, Zarb G, Worthington P, Eriksson AR. The long-term efficacy of currently used dental implants: a review and proposed criteria of success. \u003cem\u003eInt J Oral Maxillofac Implants\u003c/em\u003e. 1986;1(1):11-25.\u003c/li\u003e\n\u003cli\u003eGoodacre CJ, Kan JYK, Rungcharassaeng K. Clinical complications of osseointegrated implants. \u003cem\u003eJ Prosthet Dent\u003c/em\u003e. 1999;81(5):537-552. doi:10.1016/S0022-3913(99)70208-8\u003c/li\u003e\n\u003cli\u003eMisch CE. Consideration of biomechanical stress in treatment with dental implants. \u003cem\u003eDent Today\u003c/em\u003e. 2006;25(5):80, 82, 84-85; quiz 85.\u003c/li\u003e\n\u003cli\u003eRangert B, Krogh PH, Langer B, Van Roekel N. Bending overload and implant fracture: a retrospective clinical analysis. \u003cem\u003eInt J Oral Maxillofac Implants\u003c/em\u003e. 1995;10(3):326-334.\u003c/li\u003e\n\u003cli\u003eMendon\u0026ccedil;a G, Silveira Mendon\u0026ccedil;a DB, Fernandes-Neto AJ, Neves FD. Management of Fractured Dental Implants: A Case Report. \u003cem\u003eImplant Dent\u003c/em\u003e. 2009;18(1):10-16. doi:10.1097/ID.0b013e318192cafe\u003c/li\u003e\n\u003cli\u003eBalshi TJ. An analysis and management of fractured implants: a clinical report. \u003cem\u003eInt J Oral Maxillofac Implants\u003c/em\u003e. 1996;11(5):660-666.\u003c/li\u003e\n\u003cli\u003eVel\u0026aacute;squez-Plata D, Lutonsky J, Oshida Y, Jones R. A close-up look at an implant fracture: a case report. \u003cem\u003eInt J Periodontics Restorative Dent\u003c/em\u003e. 2002;22(5):483-491.\u003c/li\u003e\n\u003cli\u003eAdell R, Eriksson B, Lekholm U, Br\u0026aring;nemark PI, Jemt T. Long-term follow-up study of osseointegrated implants in the treatment of totally edentulous jaws. \u003cem\u003eInt J Oral Maxillofac Implants\u003c/em\u003e. 1990;5(4):347-359.\u003c/li\u003e\n\u003cli\u003eEckert SE, Meraw SJ, Cal E, Ow RK. Analysis of incidence and associated factors with fractured implants: a retrospective study. \u003cem\u003eInt J Oral Maxillofac Implants\u003c/em\u003e. 2000;15(5):662-667.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Fractured Implant, Implant Management, Implant overdenture, Narrow-diameter Implant","lastPublishedDoi":"10.21203/rs.3.rs-7133461/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7133461/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBackground: Fracture of narrow-diameter dental implants (NDIs), although uncommon, presents unique challenges and can jeopardize prosthetic stability and long-term treatment success. When a fractured implant from a full-arch overdenture is supported by several implants, management is especially challenging.\u003c/p\u003e\n\u003cp\u003eCase Presentation: This case report describes the diagnosis and surgical treatment of a broken NDI placed in a patient rehabilitated six years ago on a maxillary all-on-eight implant-retained overdenture. Clinical and radiologically based assessments confirmed a horizontal fracture in the middle third of the implant body. Implant extraction was managed by conservative extraction of the coronal portion followed by surgical excision of the apical region by trephination using radiographic imaging. The site was managed later on for potential implant placement and prosthetic re-stabilization.\u003c/p\u003e\n\u003cp\u003eConclusion: This case highlights surgical techniques and guiding principles related to the treatment of broken NDIs and relevant decision-making criteria. In order to optimize positive outcomes in complex full-arch implant procedures, the knowledge of biomechanical limitations, careful design, and appropriate retrieval approaches play a vital role.\u003c/p\u003e","manuscriptTitle":"Management of a Fractured Narrow-Diameter Dental Implant from All-on-eight Overdenture : A Case Report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-06 08:13:09","doi":"10.21203/rs.3.rs-7133461/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"7620756f-8f48-4354-a8c7-9b6403ec3e8b","owner":[],"postedDate":"August 6th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-10-03T02:23:30+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-06 08:13:09","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7133461","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7133461","identity":"rs-7133461","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}