Journal of the Mechanical Behavior of Biomedical Materials最新文献

{"title":"Optimization of endocrown design parameters for mandibular second molars: A 3D finite element analysis","authors":"Xuechun Dong ,&nbsp;Jinghao Ban ,&nbsp;Huihui Guo ,&nbsp;Ziyu Zeng ,&nbsp;Nan Ren ,&nbsp;Shizhu Bai ,&nbsp;Zhongshan Wang","doi":"10.1016/j.jmbbm.2025.107038","DOIUrl":"10.1016/j.jmbbm.2025.107038","url":null,"abstract":"<div><div>This study aimed to investigate the optimal parameters for endocrown design in mandibular second molars using three-dimensional finite element analysis. Eighteen finite element models(n = 3)were created with varying ferrule heights (0, 1, 2 mm), post space depths (2, 3, 4 mm), and diameters (2, 3 mm). The models simulated zirconia endocrowns on root canal treated teeth. Von Mises stress distribution was analyzed under 200 N oblique loading. Results showed that in butt-joint designs, increasing post space depth and diameter led to higher stress concentration at the post apex and lower stress at the mesial-buccal bonding interface. For ferrule designs, increasing ferrule height reduced stress at both the post apex and bonding interface. Stress in dentin increased with post space depth and diameter in butt-joint designs but decreased with increased ferrule height in ferrule designs. The study concluded that smaller post space dimensions (diameter and depth) reduce dentin stress in both butt-joint and ferrule endocrown designs, thereby indicating better protection of the remaining tooth structure. Ferrule designs exhibited a more uniform stress distribution compared to butt-joint designs. These findings suggest that endocrown design can be optimized to enhance stress distribution and potentially improve clinical outcomes, though further long-term clinical studies are needed to validate these results.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"168 ","pages":"Article 107038"},"PeriodicalIF":3.3,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895608","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":"Validation and application of a finite element model simulating failure thresholds of skin during blunt puncture with varying impactor geometries","authors":"Joseph LeSueur ,&nbsp;Carolyn E. Hampton ,&nbsp;Frank A. Pintar","doi":"10.1016/j.jmbbm.2025.107035","DOIUrl":"10.1016/j.jmbbm.2025.107035","url":null,"abstract":"<div><div>Injuries caused by knives or other sharp tools such as scissors and screwdrivers are common in violent crimes and self-defense acts. The force thresholds of skin have been quantified based on the puncture instrument to assess degree of force in forensic cases, but limited studies have investigated blunt instruments and the effect of skin thickness. A finite element (FE) computational model was developed to simulate blunt puncture of skin. Curve fitting and manual optimization were performed to obtain Ogden material coefficients. The model was validated with experimental force-time curves for spherical impactors of diameter 3, 5, and 8 mm into thin, average, and thick skin at slow and fast loading rates (n = 18 total conditions), resulting in an average CORA score of 0.725. The average maximum principal stress at the time of experimental failure was 57.3 MPa with a coefficient of variance of 0.18, and the median value of 54.8 MPa was selected as the failure criterion. The validated model was applied to load seven spherical impactors, five Hex screwdrivers, and three Torx screwdrivers into skin with thicknesses ranging from 2 to 3 mm. Increased skin thickness resulted in greater force, displacement, and strain energy at failure. Cross-sectional area of the impactor and failure thresholds of skin expressed a linear relationship for normalized force (R² ≥ 0.88), displacement (R² ≥ 0.77), and normalized strain energy (R² ≥ 0.92). The validated FE model may be used to determine the force required to penetrate skin with a case-specific blunt instrument.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"168 ","pages":"Article 107035"},"PeriodicalIF":3.3,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895615","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":"Comparative Evaluation of Bilayered and Monolithic Endocrowns: Fracture Resistance, Failure Mode, and Stress Distribution.","authors":"Haider Ali Ibrahim ,&nbsp;Haider Hasan Jasim ,&nbsp;Wiam Ali El Ghoul ,&nbsp;Valentin Vervack ,&nbsp;Jakub Słoniewski","doi":"10.1016/j.jmbbm.2025.107033","DOIUrl":"10.1016/j.jmbbm.2025.107033","url":null,"abstract":"<div><h3>Purpose</h3><div>To evaluate the load-to-fracture after mechanical cycling, failure mode, and stress distribution of mandibular first molars restored with monolithic lithium disilicate (LDS) endocrowns and bilayered endocrowns featuring resin-matrix ceramic endocores veneered with cemented LDS.</div></div><div><h3>Methods</h3><div>Thirty-six mandibular first molars were divided into three groups (n = 12): Group ME (monolithic LDS), Group VE (bilayered VITA Enamic endocore with LDS veneer), and Group CE (bilayered Cerasmart endocore with LDS veneer). After endodontic treatment, standardized preparation, and CAD/CAM fabrication, restorations underwent 250,000 mechanical loading cycles under a 150 N load. Surviving specimens were tested for fracture resistance, and fracture modes were classified. Finite element analysis (FEA) assessed stress distribution.</div></div><div><h3>Results</h3><div>All samples survived the load of mechanical cycling. Group VE exhibited the highest mean fracture resistance (2774.17 N), significantly higher than Groups ME (2120.75 N) and CE (1949.58 N) (p ≤ 0.05), with no significant difference between ME and CE (p &gt; 0.05). Failure mode analysis revealed reparable fracture rates of 0%, 33%, and 50% for Groups ME, VE, and CE, respectively. Fisher's Exact Test showed significantly more reparable failures in CE compared to ME (p ≤ 0.05) and no significant difference between VE and ME (p &gt; 0.05). FEA revealed lower stress concentration in the tested bilayered models compared to the monolithic LDS model, with VE exhibiting the lowest stress concentration across the restoration complex and tooth structure.</div></div><div><h3>Conclusions</h3><div>The biomechanical performance and failure reparability of bilayered endocrowns depend on the endocore material. Endocrowns with VITA Enamic endocores exhibited the highest fracture resistance and favorable stress distribution, while Cerasmart endocores had fewer irreparable failures.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"168 ","pages":"Article 107033"},"PeriodicalIF":3.3,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902049","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":"Age-dependent properties of the rabbit calf musculature — Relationship between mechanic and microstructure","authors":"Markus Böl ,&nbsp;Kay Leichsenring ,&nbsp;Steven Kutschke ,&nbsp;Fabian Walter ,&nbsp;Tobias Siebert","doi":"10.1016/j.jmbbm.2025.107008","DOIUrl":"10.1016/j.jmbbm.2025.107008","url":null,"abstract":"<div><div>In order to meet the requirements of body weight and height and the associated changing tasks and movement patterns during the growth of living bodies, significant changes in the skeletal musculature occur during this phase. In this study, the age-dependent (between 21 and 100 days) mechanical and microstructural tissue behaviour of the calf musculature, consisting of soleus muscles (SOL), gastrocnemius muscles (GAS) and plantaris muscles (PLA), was examined. To this end, cubic muscle tissue samples were examined using axial and semi-confined compression experiments. In addition, the essential muscle tissue components (muscle fibres, extracellular matrix, remaining components) were analysed. In a final step, these results were linked to morphological properties of the animals and muscles (animal mass, muscle mass, tibia length). Interestingly, the mechanical properties of the individual muscle types hardly differ from each other during growth, while both the morphological and microstructural properties change significantly. Thus, a clear increase of all morphological parameters (animal mass by 850%, muscle mass by 1000% (SOL), 1183% (GAS) and 1050% (PLA), tibia length by 235%) can be seen. In comparison, the microstructural parameters show a less consistent trend. The proportion of muscle fibres in the tissue cross-section increases by about 138% in the SOL, whereas the fibre proportion in both the GAS and PLA increases by only 109%. Consequently, the ECM proportion in the tissue cross-section decreases by 48%, 58% and 52% for SOL, GAS and PLA. Overall, the data obtained her e provides a deeper understanding of muscle growth and, in particular, of different muscle types that have different functions inside the calf. On the other hand, these data represent a good and comprehensive basis for later model developments.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"168 ","pages":"Article 107008"},"PeriodicalIF":3.3,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887495","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":"Novel guaiacol-based high-performance dimethacrylate containing fluorenyl cardo structure for dental restorative resins","authors":"Yinan Sun ,&nbsp;Lihua Hong ,&nbsp;Lin Sun ,&nbsp;Chengji Zhao","doi":"10.1016/j.jmbbm.2025.107032","DOIUrl":"10.1016/j.jmbbm.2025.107032","url":null,"abstract":"<div><div>In dentistry, the use of bisphenol A glycidyl methacrylate (Bis-GMA) is being questioned since bisphenol A is regarded as an endocrine disruptor. As alternative candidates to Bis-GMA, bio-based dental resins face the crucial challenge of low mechanical strength and high water sorption. In this study, a novel guaiacol-based dimethacrylate containing fluorenyl cardo-structure was developed to effectively improve the hydrophobicity, enhance the mechanical properties, and reduce the polymerization shrinkage of bio-based dental restorative resins. Therefore, 9, 9-bis(3-methoxy-4-glycerolate methacrylate)fluorene (BMHF-GMA) was synthesized from a new guaiacol-based bisphenol, 9, 9-bis(3-methoxy-4-phenol)fluorene (BMHF), which is a lower estrogenic activity bisphenol monomer than commercial bisphenols from the results of cell proliferation test. The experimental dental resin (5 MHMA5T) was prepared containing BMHF-GMA and triethylene glycol dimethacrylate in a 1:1 ratio. The control group (5B5T) replaced BMHF-GMA completely with Bis-GMA. Evaluation of both dental resins revealed that 5 MHMA5T possessed comparable double bond conversion (&gt;50 % in 20 s), better volumetric polymerization shrinkage (7.19 ± 0.09 %), shrinkage stress (0.92 ± 0.01 MPa in 1200 s), water sorption (39.9 ± 0.52 μg mm⁻³), water solubility (0.99 ± 0.04 μg mm⁻³) and lower cytotoxicity compared with 5B5T. 5 MHMA5T had superior mechanical properties (flexural strength: 122.30 ± 5.00 MPa; flexural modulus: 3.49 ± 0.02 GPa; Vickers hardness number: 25.21 ± 0.56 HV). Especially, after water immersion, it still maintained adequate mechanical properties (flexural strength: 97.34 ± 5.00 MPa; flexural modulus: 2.92 ± 0.02 GPa; Vickers hardness number: 19.33 ± 0.61 HV). Therefore, the new dimethacrylate BMHF-GMA shows great potential in complex and wet oral environments and offers a promising alternative to Bis-GMA in dental restorative resins.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"168 ","pages":"Article 107032"},"PeriodicalIF":3.3,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887496","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 high-throughput framework for predicting three-dimensional structural–mechanical relationships of human cranial bones using a deep learning-based method","authors":"Weihao Guo ,&nbsp;Mohammad Rezasefat ,&nbsp;Karyne N. Rabey ,&nbsp;Simon Ouellet ,&nbsp;Lindsey Westover ,&nbsp;James David Hogan","doi":"10.1016/j.jmbbm.2025.107007","DOIUrl":"10.1016/j.jmbbm.2025.107007","url":null,"abstract":"<div><div>Cranial bone injuries significantly impact human health, potentially leading to death or permanent disability, and mechanical responses are crucial predictors of cranial damage. Predicting mechanical responses through medical imaging is an efficient method that streamlines the process by eliminating the need for intermediate steps, such as diagnostic testing and biomedical analysis. Although previous studies have successfully predicted 1D sequences or 2D sectional mechanical attributes from medical imaging, these approaches are limited in their ability to capture the anisotropic characteristics of cranial bone. As a complex osseous material, cranial bone has significant directional dependencies in its microstructural features, which directly influence its macroscopic mechanical responses under loading conditions. In this study, we aim to introduce a deep learning-based high-throughput framework to correlate the three-dimensional mechanical responses and three-dimensional cranial microstructures derived from medical images. First, micro-CT scans of 40 human cranial samples, spanning an average age of 82.5 years, were performed to capture microstructural information. Next, 2000 representative volume element (RVE) units were randomly and automatically extracted from these scans to characterize the cranial microstructures. Following this, 2000 stress and 2000 strain fields were derived from finite element simulations based on these RVE units, and subsequently validated through quasi-static compression experiments. An optimized U-Net-based deep learning network was employed to link the macro-property stress–strain response with the three-dimensional cranial microstructures. The proposed framework demonstrates robust performance in predicting the spatial mechanical behavior based on microstructural inputs, showing high and consistent similarity between the predictions and ground truth. Overall, the high-throughput nature of this framework facilitates the handling of large-scale data, enabling comprehensive and efficient analysis that is crucial for predicting mechanical responses. By elucidating structure–property relationships, this approach can enhance the accuracy of injury diagnosis and aid in the development of tailored treatment plans, effectively bridging the gap between structural morphology and mechanical functionality.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"168 ","pages":"Article 107007"},"PeriodicalIF":3.3,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143903594","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":"Effect of hexagonal boron nitride (hBN) addition on microstructure, mechanical, and biocompatible properties of spark plasma sintered titanium (Ti) matrix composites","authors":"Satyavan Digole ,&nbsp;Smriti Bohara ,&nbsp;Chandrasekhar R. Kothapalli ,&nbsp;Bharat Bajaj ,&nbsp;Tushar Borkar","doi":"10.1016/j.jmbbm.2025.107030","DOIUrl":"10.1016/j.jmbbm.2025.107030","url":null,"abstract":"<div><div>A novel approach is introduced, utilizing low concentrations of hexagonal boron nitride (hBN) and fabricating titanium matrix composites (TMCs) through ball milling and spark plasma sintering (SPS). The ball-milled Ti-x wt.% hBN (x: 0.1, 0.25, and 0.5) powders sintered at 60 MPa pressure and a 5-min holding time for temperatures ranging from 900 to 1200 °C. The in-situ formation of titanium boride whiskers (TiBw) and Ti(N) solid solution occurred from the Ti and hBN particle reaction during sintering. The XRD pattern of the hBN-added sample shows α-Ti similar to pure Ti without the reaction phase due to a lower hBN fraction in Ti. However, the XRD peak shift toward a lower diffraction angle for the Ti-hBN sample confirms the formation of Ti(N) within the Ti matrix. Microstructure analysis reveals significant grain refinement with increasing hBN fraction; the grain sizes for Ti, Ti-0.1hBN, Ti-0.25hBN, and Ti-0.5hBN are 36, 22, 20, and 18 μm, respectively. The presence of TiBw and Ti(N) leads to a grain refinement effect in higher hardness and enhanced strength in composite samples. The Ti-0.25 wt% hBN sample sintered at 1200 °C exhibited an optimal combination of relative density (99.73 %), hardness (341.8 ± 6 HV), yield strength (1042 ± 21 MPa), compressive strength (1840 ± 23 MPa), and elongation (34.4 ± 1.5 %). The biocompatibility is confirmed through cell adhesion, viability, and cytotoxicity studies, highlighting these composite's excellent biocompatibility and potential for orthopedic implant application.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"168 ","pages":"Article 107030"},"PeriodicalIF":3.3,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877079","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":"Calcification-neighboring regions of atherosclerotic aortic tissue exhibit elevated stiffness without elevated radiodensity","authors":"Carly L. Donahue,&nbsp;Victor H. Barocas","doi":"10.1016/j.jmbbm.2025.107034","DOIUrl":"10.1016/j.jmbbm.2025.107034","url":null,"abstract":"<div><div>Atherosclerosis, characterized by plaque accumulation and arterial remodeling, poses significant mechanical risks to the aorta such as wall stiffening, aneurysm formation, dissection, and plaque rupture. In this study, we investigated the mechanical and imaging properties of atherosclerotic lesions and their surrounding aortic media in 19 samples dissected from the thoracic aortas of human cadavers. Local stiffness was determined via inverse mechanical analysis of planar biaxial tensile tests, and radiodensity was assessed using micro-CT imaging. Our results show that calcifications are both more radiodense and stiffer than surrounding tissue, consistent with prior studies. However, radiodensity did not reliably predict stiffness in non-calcified regions, highlighting the limitations of micro-CT in capturing mechanical heterogeneity in softer tissues. Notably, we observed a significant stiffness gradient in tissue surrounding calcifications, with stiffness decreasing exponentially with distance. The calcification's biomechanical influence extended an estimated 5.40 ± 0.43 mm into the surrounding aortic media, despite the absence of significant radiodensity gradients in these regions. These findings suggest that calcifications serve as localized mechanical stress concentrators, influencing nearby tissue stiffness beyond their immediate boundary.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"168 ","pages":"Article 107034"},"PeriodicalIF":3.3,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895614","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":"Comparative in vitro study of chondrocyte viability and gene expression in wrought and additive manufactured CoCrMo sliding against articular cartilage","authors":"Rosa Maria Nothnagel ,&nbsp;Christoph Bauer ,&nbsp;Leonarda Vukonic ,&nbsp;Tímea Váradi ,&nbsp;Friedrich Franek ,&nbsp;Stefan Nehrer ,&nbsp;Manel Rodríguez Ripoll","doi":"10.1016/j.jmbbm.2025.107024","DOIUrl":"10.1016/j.jmbbm.2025.107024","url":null,"abstract":"<div><div>Hemiarthroplasty consists of the replacement of local cartilage defects by a partial implant and provides a less aggressive alternative to total joint replacement. The material frequently selected nowadays for partial implants is CoCrMo alloy, which results in a sliding contact between articular cartilage and the alloy. Since the geometry of the implant needs to be tailored to the patient, partial implant technology would greatly profit from novel additive manufacturing techniques. This study examines the feasibility of using additive manufacturing techniques on partial implants made of CoCrMo alloys, with a particular focus on the impact of manufacturing technique on mechanical stimulation, cartilage analysis, and friction performance. To this end, in vitro biotribological experiments were performed between CoCrMo samples and bovine articular cartilage using PBS as simulated body fluid. Key findings reveal significant changes in microstructure between laser beam melted (LBM) and wrought CoCrMo alloys, despite having a comparable elemental composition. The coefficient of friction (CoF) measured between bovine articular cartilage and the CoCrMo specimens during biotribocorrosive testing revealed no significant differences resulting from the manufacturing techniques, even though wrought CoCrMo resulted in a higher reproducibility. Conventionally produced CoCrMo also exhibited a more anodic open circuit potential during the experiments, likely due to the significant differences in microstructure that affect corrosion resistance. The tested cartilage samples showed a slight increase in MMP13 (Matrix Metalloproteinases – degradative enzymes) in comparison to the controls, indicating potential remodeling effects, especially for the LBM CoCrMo alloy. Additionally, the metabolic activity in the cartilage specimens increased due to mechanical stimulation. No cracks or fissures were detected in histological imaging thus highlighting that the cartilage samples were not damaged during harvesting or testing. These findings indicate the possibility of an equivalent use of additive manufactured CoCrMo, enabling patient-specific surgeries and encourage further research to explore the long-term impact of corrosion stability on implant longevity and functionality.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"168 ","pages":"Article 107024"},"PeriodicalIF":3.3,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877068","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":"Reducing fractures in diamond-milled lithium metasilicate/disilicate glass-ceramics (LMGC/LDGC) by ultrasonic vibration-assisted machining","authors":"Afifah Z. Juri ,&nbsp;Xiangtian Lei ,&nbsp;James Dudley ,&nbsp;Ulrich Lohbauer ,&nbsp;Grace M. De Souza ,&nbsp;Yoshitaka Nakanishi ,&nbsp;Ling Yin","doi":"10.1016/j.jmbbm.2025.107029","DOIUrl":"10.1016/j.jmbbm.2025.107029","url":null,"abstract":"<div><div>Digital CAD/CAM milling of aesthetic glass-ceramics in dental restorations induces extensive surface damage to the materials, jeopardising the quality of the restorations. This study aimed to reduce fractures in lithium metasilicate and disilicate glass-ceramics (LMGC and LDGC) induced by novel ultrasonic vibration-assisted machining for improved surface quality. Ultrasonic vibration-assisted machining of LMGC and LDGC was performed using a digital high-speed ultrasonic milling machine. Machining-induced surface fractures were quantitatively assessed in terms of 3D surface height, spatial, and hybrid parameters as a function of vibration amplitudes using a 3D white light profilometer. Damage morphologies were examined using scanning electron microscopy (SEM). Machining-induced surface fractures significantly depended on material microstructures, mechanical properties associated with brittleness and machinability indices, and ultrasonic machining vibration amplitudes. Higher brittleness indexed LMGC produced more surface damage than LDGC. Thus, LMGC surfaces had significantly higher 3D surface height, spatial, and hybrid parameters than LDGC, except texture aspect ratios. Brittle fracture dominated all material removal but ultrasonic machining at an optimized vibration amplitude of 3 μm promoted localized ductile deformation in LMGC and LDGC, and significantly improved the surface quality. Ultrasonic vibration-assisted machining at the optimized vibration amplitude enabled the surface quality improvement for both LMGC and LDGC. Further, one-step (direct) machining of LDGC can be approached for rapid high-quality ceramic restorations, replacing the two-step procedure for LMGC and saving the fabrication time.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"168 ","pages":"Article 107029"},"PeriodicalIF":3.3,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895613","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}