Journal of the Mechanical Behavior of Biomedical Materials最新文献

{"title":"Developing porous hip implants implementing topology optimization based on the bone remodelling model and fatigue failure","authors":"Babak Ziaie ,&nbsp;Xavier Velay ,&nbsp;Waqas Saleem","doi":"10.1016/j.jmbbm.2024.106864","DOIUrl":"10.1016/j.jmbbm.2024.106864","url":null,"abstract":"<div><div>In contemporary orthopaedic practice, total hip arthroplasty (THA) is a reliable surgical technique for hip joint replacement. However, introducing solid implants into human bone tissue can lead to complications, notably stress shielding and cortical hypertrophy. These issues often stem from mechanical mismatches, particularly stiffness disparities, between the solid implants and the bone tissue. A potential solution lies in adopting porous implant structures with lower stiffness and tuneable mechanical properties based on morphological parameters such as porosity, relative density, and unit cell sizes. This study, which is of significant importance to orthopaedic implant development, aims to develop porous implants that meet biological and manufacturing requirements, employing topology optimization methods to address the challenges associated with conventional solid implants. To achieve this objective, we conducted finite element analyses to compare the stress distribution within healthy bones with solid and newly developed porous implants under real-life loading conditions. The porous implants were designed with triply periodic minimal surface structures, featuring uniform relative density and gradient relative density mapping derived from topology optimization results considering additive manufacturing capabilities and biological constraints. Our findings provide critical insights into the impact on the bone's mechanical environment about the choice of implant. Specifically, solid implants significantly decrease applied stress within the cortical bone, leading to stress shielding and subsequent bone resorption, consistent with bone remodelling principles and Wolff's law. However, replacing the solid implant with uniform porosity with maximum compliance and employing gradient porous implants based on topology optimization methods significantly increases the strain energy density ratio. Specifically, the uniform gyroid, uniform diamond, gradient gyroid, and gradient diamond stems exhibited increases of 43%, 39%, 27%, and 25%, respectively, compared to the solid stem, effectively mitigating the stress shielding effect. However, amongst porous stems, only gradient designs could meet the mechanical strength requirements with a safety factor greater than one, rendering them suitable replacements for solid implants aimed at addressing associated complications. These results hold promise, particularly with the advancements in additive manufacturing methods capable of fabricating these porous implants with acceptable precision.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106864"},"PeriodicalIF":3.3,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142866779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Poroelastic and viscoelastic properties of soft materials determined from AFM force relaxation and force-distance curves","authors":"Stéphane Cuenot ,&nbsp;Arnaud Fillaudeau ,&nbsp;Tina Briolay ,&nbsp;Judith Fresquet ,&nbsp;Christophe Blanquart ,&nbsp;Eléna Ishow ,&nbsp;Agata Zykwinska","doi":"10.1016/j.jmbbm.2024.106865","DOIUrl":"10.1016/j.jmbbm.2024.106865","url":null,"abstract":"<div><div>In the field of tissue engineering, determining the mechanical properties of hydrogels is a key prerequisite to develop biomaterials mimicking the properties of the extracellular matrix. In mechanobiology, understanding the relationships between the mechanical properties and physiological state of cells is also essential. Time-dependent mechanical characterization of these soft materials is commonly achieved by atomic force microscopy (AFM) experiments in liquid environment. However, the determination of an appropriate model to correctly interpret the experimental data is often missing, making it difficult to extract quantitative mechanical properties. Here, force relaxation and force-distance curves were combined to elucidate the origin of dissipative processes involved in hydrogels and cells, before applying the relevant poroelastic or viscoelastic theory to model the curves. By using spherical AFM tips, analytical equations were developed to transform these curves into mechanical parameters by describing the relationships between the exerted force and the elastic, poroelastic or viscoelastic responses of semi-infinite and finite-thickness materials. Poroelastic behavior was evidenced for a thermoresponsive hydrogel and a set of poroelastic parameters was extracted from the force relaxation curves. In contrast, cells exhibited viscoelastic properties characterized by a single power-law relaxation over three-decade time scales. In addition, compressive modulus and fluidity exponent of cells were obtained by fitting force relaxation curves and approach-retraction force-distance curves. This combined theoretical and experimental framework opens a rigorous way toward quantitative mechanical properties of soft materials by (1) systematically determining the origin of their relaxation mechanisms, (2) defining the theoretical models to correctly interpret the experimental data, (3) using analytically solved equations to extract the mechanical parameters.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106865"},"PeriodicalIF":3.3,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142815433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Super-fast and accurate nonlinear foot deformation Prediction using graph neural networks","authors":"Taehyeon Kang ,&nbsp;Jiho Kim ,&nbsp;Hyobi Lee ,&nbsp;Haeun Yum ,&nbsp;Chani Kwon ,&nbsp;Youngbin Lim ,&nbsp;Sangryun Lee ,&nbsp;Taeyong Lee","doi":"10.1016/j.jmbbm.2024.106859","DOIUrl":"10.1016/j.jmbbm.2024.106859","url":null,"abstract":"<div><div>Recently, there has been a significant increase in the number of foot diseases, highlighting the importance of non-surgical treatments. Customized insoles, tailored to an individual's foot morphology, have emerged as a promising solution. However, the traditional design process of the customized insole is both slow and expensive due to the high computational complexity of finite element analysis (FEA) required to predict deformations of the foot. This study explores the applicability of a graph neural network (GNN) based on the MeshGraphNet framework to predict the 3-D shape of the foot under load and test the performance of GNN depending on the number of datasets. A total of 186 3-D undeformed foot CAD geometries are obtained from a series of 2-D foot images with deformations predicted through FEA. This FEA data is then used to train the GNN model, which aims to predict foot displacement with high accuracy and computation speed. After optimization of the weights of the GNN, the model remarkably outperformed FEA simulations in speed, being approximately 97.52 times faster, while maintaining high accuracy, with <em>R</em>² values above 95% in predicting foot displacement. This breakthrough suggests that GNN models can greatly improve the efficiency and reduce the cost of manufacturing customized insoles, providing a significant advancement in non-surgical treatment options for foot conditions.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106859"},"PeriodicalIF":3.3,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142823027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vivo assessment of shear modulus along the fibers of pennate muscle during passive lengthening and contraction using steered ultrasound push beams","authors":"Ricardo J. Andrade ,&nbsp;Ha-Hien-Phuong Ngo ,&nbsp;Alice Lemoine ,&nbsp;Apolline Racapé ,&nbsp;Nicolas Etaix ,&nbsp;Thomas Frappart ,&nbsp;Christophe Fraschini ,&nbsp;Jean-Luc Gennisson ,&nbsp;Antoine Nordez","doi":"10.1016/j.jmbbm.2024.106862","DOIUrl":"10.1016/j.jmbbm.2024.106862","url":null,"abstract":"<div><div>Ultrasound shear wave elastography (SWE) has emerged as a promising non-invasive method for muscle evaluation by assessing the propagation velocity of an induced shear wavefront. In skeletal muscles, the propagation of shear waves is complex, depending not only on the mechanical and acoustic properties of the tissue but also upon its geometry. This study aimed to comprehensively investigate the influence of muscle pennation angle on the shear wave propagation, which is directly related to the shear modulus. A novel elastography method based on steered pushing beams (SPB) was used to assess the shear modulus along the fibers of the <em>gastrocnemius medialis</em> (pennate) muscle in twenty healthy volunteers. Ultrasound scans were performed during passive muscle lengthening (n = 10) and submaximal isometric contractions (n = 10). The shear modulus along the fibers was compared to the apparent shear modulus, as commonly assessed along the muscle shortening direction using conventional SWE sequences. The shear modulus along the muscle fibers was significantly greater than the apparent shear modulus for passive dorsiflexion angles, while not significantly different throughout the range of plantar flexion angles (i.e., under any or very low tensile loads). The concomitant decrease in pennation angle along with the gradual increase in the shear modulus difference between the two methods as the muscle lengthens, strongly indicates that non-linear elasticity exerts a greater influence on wave propagation than muscle geometry. In addition, significant differences between methods were found across all submaximal contractions, with both shear modulus along the fibers and the pennation angle increasing with the contraction intensity. Specifically, incremental contraction intensity led to a greater bias than passive lengthening, which could be partly explained by distinct changes in pennation angle. Overall, the new SPB sequence provides a rapid and integrated geometrical correction of shear modulus quantification in pennate muscles, thereby eliminating the necessity for specialized systems to align the ultrasound transducer array with the fiber's orientation. We believe that this will contribute for improving the accuracy of SWE in biomechanical and clinical settings.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106862"},"PeriodicalIF":3.3,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142815432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of structural design on the mechanical performances of poly-L-lactic acid cardiovascular scaffolds using FEA and in vitro methods","authors":"Jinwoo Kim ,&nbsp;Hyeon Ji Lee ,&nbsp;Eun Ae Choi ,&nbsp;Jung Ho Lee ,&nbsp;Jin Oh ,&nbsp;Dae-Heung Byeon ,&nbsp;Hyo Sung Kwak ,&nbsp;Chan Hee Park","doi":"10.1016/j.jmbbm.2024.106849","DOIUrl":"10.1016/j.jmbbm.2024.106849","url":null,"abstract":"<div><h3>Objective</h3><div>In this study, we propose distinct and novel types of scaffold geometries to improve the mechanical performance of Poly-L-lactic Acid (PLLA) bioresorbable vascular scaffolds (BVS), investigating how different geometries of PLLA BVS influence their mechanical performances through finite element analysis (FEA) and in vitro experiment methods.</div></div><div><h3>Methods</h3><div>Four different types of scaffold geometries were modelled for FEA and manufactured for in vitro experiments. PLLA tubes with 110 μm thickness were used in manufacturing the scaffolds. For FEA measurements, material properties and bilinear material models were obtained from tensile testing using the PLLA tubes employed for manufacturing. Various measurements were conducted including crush resistance, radial strength in both the laser-cut and deployed state, three-point bending, and scaffold crimping/expansion test.</div></div><div><h3>Results</h3><div>Overall, the FEA results were similar to the experimental results. Design A, which had a conventional open-cell geometry with straight bridges, showed inferior crush resistance and radial strength to those of the other tested geometries. Design B exhibited the most well-balanced scaffold performances in terms of radial strengths, crush resistance, three-point bending, and crimping/expansion behaviors. Notably, it showed minimum plastic strain during crimping and expanding deformations in FEA.</div></div><div><h3>Conclusions</h3><div>Findings from such distinct and novel types of scaffold geometries shown by this study may provide a valuable understanding using PLLA scaffolds as cardiovascular devices.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106849"},"PeriodicalIF":3.3,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142804291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A computational framework to optimize the mechanical behavior of synthetic vascular grafts","authors":"David Jiang ,&nbsp;Andrew J. Robinson ,&nbsp;Abbey Nkansah ,&nbsp;Jonathan Leung ,&nbsp;Leopold Guo ,&nbsp;Steve A. Maas ,&nbsp;Jeffrey A. Weiss ,&nbsp;Elizabeth M. Cosgriff-Hernandez ,&nbsp;Lucas H. Timmins","doi":"10.1016/j.jmbbm.2024.106847","DOIUrl":"10.1016/j.jmbbm.2024.106847","url":null,"abstract":"<div><div>The failure of synthetic small-diameter vascular grafts has been attributed to a mismatch in the compliance between the graft and native artery, driving mechanisms that promote thrombosis and neointimal hyperplasia. Additionally, the buckling of grafts results in large deformations that can lead to device failure. Although design features can be added to lessen the buckling potential (e.g., reinforcing coil), the addition is detrimental to decreasing compliance. Herein, we developed a novel finite element (FE) framework to inform vascular graft design by evaluating compliance and resistance to buckling. A batch-processing scheme iterated across the multi-dimensional design parameter space, which included three parameters: coil thickness, modulus, and spacing – generating 100 unique designs. FE models were created for each coil-reinforced graft design to simulate pressurization, axial buckling, and bent buckling, and results were analyzed to quantify compliance, buckling load, and kink radius, respectively. Validation of the FE models demonstrated that model predictions agreed with experimental observations for compliance (<span><math><mrow><mi>r</mi></mrow></math></span> = 0.99), buckling load (<span><math><mrow><mi>r</mi></mrow></math></span> = 0.89), and kink resistance (<span><math><mrow><mi>r</mi></mrow></math></span> = 0.97). Model predictions demonstrated a broad range of values for compliance (1.1–7.9 %/mmHg × 10⁻²), buckling load (0.28–0.84 N), and kink radius (6–10 mm) across the design parameter space. Subsequently, data for each design parameter combination were optimized (i.e., minimized) to identify candidate graft designs with promising mechanical properties. Our model-directed framework successfully elucidated the complex mechanical determinants of graft performance, established structure-property relationships, and identified vascular graft designs with optimal mechanical properties, potentially improving clinical outcomes by addressing device failure.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106847"},"PeriodicalIF":3.3,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142873743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced mechanical strength and bioactivity of 3D-printed β-TCP scaffolds coated with bioactive glasses","authors":"Márcia Cristina Bezerra Melo ,&nbsp;Bruno Roberto Spirandeli ,&nbsp;Lucas Barbosa ,&nbsp;Verônica Ribeiro dos Santos ,&nbsp;Tiago Moreira Bastos de Campos ,&nbsp;Gilmar Patrocínio Thim ,&nbsp;Eliandra de Sousa Trichês","doi":"10.1016/j.jmbbm.2024.106850","DOIUrl":"10.1016/j.jmbbm.2024.106850","url":null,"abstract":"<div><div>3D printing in scaffold production offers a promising approach, enabling precise architectural design that closely mimics the porosity and interconnectivity of natural bone. β-Tricalcium phosphate (β-Ca₃(PO₄)₂, β-TCP), with a chemical composition similar to the inorganic component of bone, is a widely used material for scaffold fabrication. Recent advances have made it possible to functionalize ceramic scaffolds to improve bone regeneration and repair while enabling the in situ release of therapeutic agents to treat bone infections. In this study, 3D-printed β-TCP scaffolds were coated with bioactive glasses, 45S5 (45SiO₂ – 24.5Na₂O – 24.5CaO – 6P₂O₅, wt.%) and 58S (58SiO₂ – 33CaO – 9P₂O₅, wt.%), using sol-gel solutions through a vacuum impregnation technique. The β-TCP ink exhibited pseudoplastic behavior, which facilitated its 3D printing. The resulting scaffolds demonstrated high fidelity to the designed model, featuring well-aligned filaments and minimal collapse of the lower layers after sintering. Elemental mapping revealed that 45S5 glass formed a surface coating around the scaffold struts, whereas 58S glass penetrated the internal structure, this occurred due to their differing viscosities at high temperatures. Compared to uncoated β-TCP scaffolds, the coatings significantly improved mechanical strength, with increases of 63% and 126% for scaffolds coated with 45S5 and 58S, respectively. Bioactivity was confirmed through an apatite mineralization assay in simulated body fluid, which demonstrated hydroxyapatite precipitation on both coated scaffolds, albeit with distinct morphologies. Since this study focused on acellular scaffolds, further research is necessary to fully explore the potential of these bioactive scaffolds with optimized mechanical properties in biological systems.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106850"},"PeriodicalIF":3.3,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142792997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical behaviour of additive manufactured PEEK/HA porous structure for orthopaedic implants: Materials, structures and manufacturing processes","authors":"Qing Zhang ,&nbsp;Changning Sun ,&nbsp;Jibao Zheng ,&nbsp;Ling Wang ,&nbsp;Chaozong Liu ,&nbsp;Dichen Li","doi":"10.1016/j.jmbbm.2024.106848","DOIUrl":"10.1016/j.jmbbm.2024.106848","url":null,"abstract":"<div><div>Polyether-ether-ketone (PEEK) composites represent one of the most promising approaches to overcoming the weak osseointegration associated with the bioinertness of PEEK, making them highly suitable for clinical translation. Implants with porous structures fabricated by additive manufacturing offer the potential for long-term stability by promoting bone ingrowth. However, despite the importance of porous design, there is still no consensus on the optimal approach for PEEK-based composites. Given the significance of permeability and mechanical properties as functional indicators closely linked to osseointegration, the effects of material composition, structural design, and manufacturing processes on the permeability and mechanical properties of PEEK/hydroxyapatite (HA) scaffolds were systematically investigated in this study. In terms of permeability, the axial permeability of scaffolds with different pore sizes and representative volume elements varied within the range of 0.3–24.8 × 10⁻⁹ m². Among scaffolds with similar relative density, the Gyroid structure exhibited the lowest permeability, while the orthogonal structure demonstrated the highest. For cylindrical scaffolds, circumferential permeability decreased with increasing penetration depth, suggesting a potential reduction in bone ingrowth speed with depth. As for mechanical properties, the experimentally determined effective elastic modulus and effective yield strength of the scaffolds ranged from 675.1 MPa to 65.2 MPa and 43.5 MPa to 4.1 MPa, respectively. The permeability and mechanical properties of PEEK/HA scaffolds with relative density ranging from 35% to 50% were aligned with the those of human cancellous bone. Heat treatment at 240 °C for 120 min increased the crystallinity of PEEK to 37.2%, resulting in a substantial improvement in both the strength and stiffness of the scaffolds. However, excessive crystallinity led to brittle fracture, which in turn reduced the strength of the scaffolds. This study employed a systematic research approach to investigate how material composition, structural design, and manufacturing processes influence the mechanical properties and permeability of PEEK composite bone scaffolds, which are crucial for bone ingrowth. The results offered insights that support the design, manufacturing, and performance evaluation of PEEK-based porous implants.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106848"},"PeriodicalIF":3.3,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142823025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved mechanical performance and forming accuracy of ZrO2 fixed partial denture based on the digital light processing technology","authors":"Rongfang Zou ,&nbsp;Xiaohong Han ,&nbsp;Yang Meng ,&nbsp;Wenbin Chen ,&nbsp;Zhiyun Shi ,&nbsp;Yilin Lian ,&nbsp;Fangping Wang ,&nbsp;Mingzhen Wang ,&nbsp;Yang Huang","doi":"10.1016/j.jmbbm.2024.106840","DOIUrl":"10.1016/j.jmbbm.2024.106840","url":null,"abstract":"<div><div>Fixed partial dentures are the primary treatment for dentition defects. Digital light processing (DLP) 3D printing technology is an advanced technique with significant advantages and potential in the field of dental restoration, particularly in cases requiring high precision and personalization. However, challenges persist in printing fixed partial dentures that meet the strength requirements for clinical applications. In this study, we aimed to optimize printing parameters, including exposure time and layer thickness, to enhance dimensional accuracy, reduce warpage, and improve the surface quality of the samples. Additionally, we focused on the rheological and curing properties of the paste. The optimal combination of printing parameters was found to be 5 s of exposure time and 50 μm layer thickness, achieving superior dimensional accuracy, reduced warpage, and improved surface quality. For a slurry with 40% solid content, the dispersant KOS 110 demonstrated the best shear thinning effect, with an optimal addition of 2%. Notably, the Vickers hardness, flexural strength, and fracture toughness of the ZrO₂ fixed partial dentures were 13.52 ± 0.21 GPa, 940 ± 20 MPa, and 6.92 ± 0.25 MPa·m1/2, respectively, which surpasses that of human enamel (4 GPa) and is comparable to CAD/CAM ZrO₂ (900–1200 MPa). This study demonstrates that DLP technology can be effectively used to fabricate ZrO₂ personalized complex fixed partial dentures with excellent mechanical properties and high precision, offering broad application prospects in stomatology.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106840"},"PeriodicalIF":3.3,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vitro fatigue of human flexor digitorum tendons","authors":"Colin R. Firminger ,&nbsp;Nicholas C. Smith ,&nbsp;W. Brent Edwards ,&nbsp;Sean Gallagher","doi":"10.1016/j.jmbbm.2024.106842","DOIUrl":"10.1016/j.jmbbm.2024.106842","url":null,"abstract":"<div><div>Carpal tunnel syndrome and stenosing tenosynovitis (i.e., trigger finger) are common work-related musculoskeletal disorders (WMSDs) that have been linked to overuse of the flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS) tendons of the hand. These injuries occur in response to repetitive loading; as such, they may be characterized using fatigue failure phenomenon. Current WMSD evaluation tools for carpal tunnel syndrome and trigger finger are built upon fatigue data from lower-limb tendons, however this may lead to inaccurate conclusions when assessing overuse injury risk at the wrist. Therefore, the purpose of this study was to characterize the fatigue behaviour of FDP and FDS tendons. We found that similar to other tendons, cyclically loaded FDP and FDS tendons illustrated a logarithmic relationship between applied stress and fatigue life, however the exact parameters of the FDP/FDS stress-fatigue life relationship were unique and may improve the accuracy of current carpal tunnel syndrome and trigger finger WMSD evaluation tools. We also observed that creep and damage rate had the strongest correlations with fatigue life, suggesting that these metrics may represent promising future directions for WMSD risk evaluation.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106842"},"PeriodicalIF":3.3,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142793000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}