To improve the mechanical reliability of thin-walled lithium disilicate (LD) veneers, this study developed a strengthening strategy that integrates vat photopolymerization (VP) with a two-step ion-exchange (IE) process. VP was employed to fabricate thin-walled LD structures, eliminating machining-induced damage, while a sequential K+/Rb+ IE process achieved both sufficient IE depth and compressive stress, overcoming their conventional trade-off. The two-step IE process increased the flexural strength of LD by 52.0% to 448.6 +/- 31.5 MPa and improved the fracture toughness by 80.4% to 2.64 +/- 0.10 MPa m1/2 . The significant enhancement in mechanical performance was mainly attributed to a 349% increase in compressive stress (CS), reaching 141.9 +/- 4.4 MPa. The atomic force microscope revealed that the ultrahigh CS was attributed to the volumetric expansion of an amorphous phase. Under scratching loads of 100 mN above the brittle-ductile transition threshold (similar to 70mN), the coefficient of friction of IE-processed LD increased by nearly 50%, indicating a transition in energy dissipation from brittle crack initiation to localized plastic deformation. Overall, the VP-fabricated LD, after undergoing the two-step IE processing, exhibits markedly enhanced strength and toughness. This improved mechanical performance effectively resists crack initiation and propagation caused by sharp contacts, thereby contributing to the superior long-term reliability of the LD veneers in the oral masticatory environment. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Zn-0.4 Sr and Zn-0.8 Sr (wt%) alloys (denoted ZS0.4 and ZS0.8) were processed by a single-pass friction stir processing (FSP) using a non-shouldered spiral tool (10 mm diameter, 2° tilt angle) at 1300 rpm, 200 mm/min traverse speed, and ∼1 mm plunge depth at room temperature. Mechanical properties were evaluated using tensile testing, nanoindentation, and Vickers and Brinell hardness measurements. Corrosion and degradation behaviors were assessed via electrochemical polarization and 30-day immersion in Hanks' solution and DMEM + FBS. Tribocorrosion resistance was examined by reciprocating friction tests under dry conditions and in liquid-wetted environments of Hanks' solution and DMEM + FBS. Biological performance was assessed using MC3T3-E1, MG-63, and hBMSC cultures, along with a rat subcutaneous implantation model. The horizontally tested ZS0.8 exhibited an exceptional strength-elongation product of 4.1 GPa%, with an ultimate tensile strength of 258 MPa, a yield strength of 210 MPa, an elongation of 15.9%, and a nanoindentation hardness of 2.6 GPa for the SrZn13 phase, compared with 0.7 GPa for the α-Zn matrix. Electrochemical corrosion rates of ZS0.8 were 388 μm/y in Hanks' and 216 μm/y in DMEM + FBS, while 30-day degradation rates were 44.9 μm/y and 27.2 μm/y, respectively. ZS0.8 also exhibited superior tribocorrosion resistance. Biologically, 25% and 50% extracts of ZS0.8 enhanced MC3T3-E1 and MG-63 viability, promoted hBMSC osteogenic differentiation and mineralization, showed potent anti-Staphylococcus aureus activity both in vitro and in vivo, and maintained good biosafety. These findings demonstrate a favorable balance of mechanical, degradation, and biological properties for load-bearing bone-fixation applications.

BACKGROUND:The treatment of infected bone defects remains challenging due to persistent infection, insufficient local drug delivery, and a disrupted repair microenvironment. Conventional porous titanium (Ti) scaffolds lack antibacterial functionality, while systemic antibiotics often fail to achieve adequate local concentrations. To address these limitations, this study designed a composite scaffold integrating localized sustained-release antibacterial capability and mechanical compatibility. METHODS:A gyroid porous Ti scaffold with ∼74% porosity and ∼0.82 mm pore size was fabricated via selective laser melting. It was subsequently infused with a sodium alginate/gelatin (SG) hydrogel loaded with kanamycin sulfate (KS) at concentrations of 2.5, 5.0, and 10.0 mg/mL, forming Ti@SG + KS2.5, Ti@SG + KS5, and Ti@SG + KS10 composite scaffolds. These were characterized for microstructure, mechanical properties, drug release, antibacterial activity, and biocompatibility through in vitro and in vivo evaluations, including antibacterial and antibiofilm assays, cell-migration and tube-formation tests, subcutaneous implantation, and an infected bone defect model in rats. RESULTS:The composite scaffolds retained an open gyroid pore structure with mechanical properties suitable for bone repair, exhibiting compressive yield strengths of 27.9-29.2 MPa and elastic moduli of 0.55-0.58 GPa. The Ti@SG + KS10 scaffold demonstrated strong and sustained antibacterial and antibiofilm activity against Escherichia coli and Staphylococcus aureus, promoted collagen deposition, and suppressed excessive inflammation. In a rat infected bone defect model, it effectively eradicated local infection and significantly enhanced trabecular bone formation, with bone volume and maturity markedly exceeding those of the pure Ti control, along with notable systemic biosafety. SIGNIFICANCE:This study successfully developed a multifunctional Ti‑based composite scaffold that provides mechanical support, localized sustained antibacterial release, and osteogenic enhancement. The scaffold effectively addresses key challenges in the repair of infected bone, such as infection control and microenvironment regulation, thereby offering a promising integrated strategy for the clinical management of infected bone defects.

Additive manufacturing offers an effective approach for fabricating biodegradable porous scaffolds that can adapt to the mechanical properties of jawbones. Zinc (Zn) and its alloys are considered promising degradable materials due to their appropriate degradation rates, favorable mechanical properties, and diverse biological functionalities. Zinc oxide (ZnO) has been shown to promote the growth of vascular endothelial cells and significantly enhance the vascularization ability of implant materials. In this study, a porous ZnO/Zn scaffold with a triply periodic minimal surface (TPMS) structure and ∼75% porosity was fabricated via binder-jetting 3D printing and subsequently sintered at 800, 900, 1000, and 1100°C. The sintered scaffold was systematically evaluated for its microstructure, mechanical properties, corrosion resistance, and biological properties both in vitro and in vivo. The results demonstrated that the porous ZnO/Zn scaffold contained α-Zn and ZnO phases, and with increasing sintering temperature, the α-Zn phase gradually transformed into ZnO, leading to a progressive decrease in degradation rate and Zn2+ release. The sintered scaffold exhibited compressive strength comparable to cancellous bone, good cytocompatibility, enhanced osteogenic and angiogenic potential in vitro, and measurable antibacterial properties. Furthermore, the scaffold effectively promoted bone integration in vivo, suggesting its potential for the repair of oral and maxillofacial bone defects, although further studies and clinical validation are required. STATEMENT OF SIGNIFICANCE: This work reports the successful fabrication and comprehensive evaluation of a porous ZnO/Zn scaffold featuring a triply periodic minimal surface (TPMS) structure, fabricated via binder-jetting 3D printing technology, for next-generation maxillofacial bone-defect repair. Our findings demonstrated that the 75% porosity scaffold exhibits compressive strength comparable to human cancellous bone, satisfying the mechanical requirements for jawbone applications. The scaffold integrates robust biocompatibility with multifunctional bioactivity, as its composition potently promotes osteoblast viability, enhances vascular endothelial cell growth, and stimulates osteogenic differentiation in vitro. Critically, the scaffold demonstrates notable in vitro antibacterial properties and effectively promotes bone integration in vivo, positioning it as a promising degradable implant with tailored mechanical adaptation and enhanced vascularization capability for maxillofacial reconstruction.

Biodegradable Zn alloys have attracted considerable attention as candidates for load-bearing bone-fixation implants, yet simultaneously optimizing mechanical strength, corrosion-wear resistance, and multifunctional biofunctionalities remains challenging. Herein, a Zn-3Cu-0.8Sr (ZCS) alloy was successfully fabricated by a synergistic processing route that integrated hot rolling (HR) with deep-cryogenic rolling (DCR). The HR+DCR processing effectively refined coarse and brittle SrZn13 and primary ε-CuZn5 phases into uniformly dispersed, well-bonded fine reinforcements, while simultaneously promoting grain coarsening and precipitate growth by suppressing dynamic recovery and restricting atomic diffusion at cryogenic temperatures. This microstructural engineering strategy produced an optimal combination of mechanical properties, including an ultimate tensile strength (σuts) of ∼301.7 MPa, a yield strength of ∼245.0 MPa, an elongation at break (ε) of ∼33.5%, the lowest σuts loss of 12.5% and ε loss of 6.6% after 30 d of immersion in Hanks' Balanced Salt Solution, and the highest biotribological resistance among all thermomechanically processed specimens. The HR+DCR processed specimen exhibited the lowest electrochemical corrosion rate of ∼162 µm/y and degradation rate of ∼20.1 µm/y in Dulbecco's Modified Eagle Medium with fetal bovine serum among all thermomechanically processed specimens. Notably, the alloy displayed enhanced osteoblast viability, osteogenic differentiation and mineralization, and near-complete antibacterial activity against Staphylococcus aureus in both in vitro and in vivo settings. Moreover, the alloy effectively modulated the immune response, driving macrophage polarization toward a pro-healing M2 phenotype. Overall, the alloy combines high mechanical, biotribological, degradation, osteogenic, antibacterial, and immunomodulatory biofunctions, underscoring its potential for next-generation biodegradable orthopedic-fixation devices. STATEMENT OF SIGNIFICANCE: This work reports a multifunctional Zn-3Cu-0.8Sr alloy fabricated using a synergistic hot rolling and deep-cryogenic rolling process for next-generation orthopedic applications. The alloy exhibits exceptional mechanical properties: σUTS of ∼301.7 MPa, σYS of ∼245.0 MPa, and ε of ∼33.5%, with minimal strength/ductility loss after 30-day immersion in Hanks' Balanced Salt Solution (HBSS). It demonstrates a favorable electrochemical corrosion rate (∼162 µm/y), degradation rate (∼20.1 µm/y), and superior biotribological resistance in Dulbecco's Modified Eagle Medium supplemented with fetal bovine serum (DMEM+FBS). Biologically, it enhances osteoblast viability and mineralization while providing near-complete S. aureus antibacterial efficacy in vitro and in vivo. This synergistic combination of strength, corrosion-wear resistance, and bioactivity highlights the alloy's significant potential for advanced biodegradable orthopedic applications.

Magnesium (Mg) alloys have shown great potential as biodegradable orthopedic-fixation materials owing to their favorable degradability, elastic modulus comparable to that of natural bone, and beneficial biological functionalities. However, their rapid degradation, poor biotribological performance, and insufficient biofunctionality limit their clinical application. To overcome these limitations, this study developed a biodegradable Mg-1Sr-1Zr-3Ho (MSZH) alloy using a combined approach of multi-elemental alloying, ultrasonic vibration, and hot extrusion. The hot-extruded (HE) MSZH alloy demonstrated an ultimate tensile strength of similar to 293 MPa, tensile yield strength of similar to 212 MPa, elongation at break of similar to 11.5%, ultimate compressive strength of similar to 513 MPa, compressive yield strength of similar to 194 MPa, and compressive strain of similar to 17.6%, all of which exceeded those of the HE Mg-1Sr-1Zr (MSZ). The HE MSZH displayed the lowest electrochemical corrosion rate of approximately 0.19 mm/y and degradation rates of 0.42 mm/y via weight loss and 1.20 mm/y via hydrogen evolution after 7 d of immersion in Dulbecco's Modified Eagle Medium+fetal bovine serum among all samples, indicating markedly improved corrosion resistance compared with MSZ. The 25% HE MSZH extract demonstrated exceptional cytocompatibility, angiogenic activity, osteogenic differentiation, and mineralization. Additionally, the HE MSZH exhibited significant antibacterial and anti-inflammatory activities against Staphylococcus aureus in vitro and in vivo. In a rat femoral-defect model, it showed further enhanced angiogenesis, bone-tissue regeneration, integration, and an in vivo degradation rate of 0.93 mm/y while demonstrating favorable biosafety compared with pure Mg.

Advanced therapies are warranted for oral ulcers considering the limited efficacy of existing treatments. We developed a multifunctional hydrogel, Cur&bFGF@FQCT, coloaded with curcumin (Cur) and basic fibroblast growth factor (bFGF), via hydrogen bonding and dynamic Schiff base interactions among FQCT constituents—aldehyde-functionalized F108, quaternized chitosan, and a chitosan–caffeic acid conjugate. The hydrogel exhibited good injectability, self-healing, and robust tissue adhesion. Curcumin was encapsulated within aldehyde-functionalized F108 micelles and bFGF was integrated into the FQCT matrix, enabling their controlled release triggered by hydrogen peroxide and oxidative stress in the oral microenvironment. Curcumin exerted potent antibacterial, antioxidant, anti-inflammatory, and pro-healing effects. Quaternary ammonium salts, catechol groups, and curcumin synergistically disrupted cell membrane and mitochondrial function in bacteria and Candida albicans, achieving robust antimicrobial activity. The hydrogel alleviated oxidative stress by reducing reactive oxygen species levels and enhancing antioxidant enzyme activities via the Nrf2/HO-1 pathway. It also suppressed activated macrophage proliferation and promoted M1-to-M2 polarization, effectively reducing inflammation. The combination of curcumin and bFGF was associated with enhanced endothelial cell proliferation, migration, and angiogenesis, accelerating tissue repair. The Cur&bFGF@FQCT hydrogel demonstrated excellent biocompatibility and improved the healing of mixed bacterial colony-induced oral ulcers. This innovative hydrogel provides a promising platform for advanced oral ulcer management and wound-healing applications.

Biodegradable Fe-based alloys face significant challenges, including the strength-plasticity trade-off and limited biofunctionality, which severely restrict their clinical orthopedic application in orthopedics. Here, we report on a nano-heterostructural Fe-15Mn-0.6Se (wt.%) alloy with low magnetism, ultrahigh strength-elongation product, and potent antibacterial and antitumor capabilities. Due to its alternating nano-layered heterostructure of γ/ε/γ (γ-austenite, ε-martensite), the Fe-15Mn-0.6Se alloy exhibited extraordinary comprehensive mechanical properties with a yield strength of 1463 ± 5 MPa, an ultimate tensile strength of 1511 ± 4 MPa, and a fracture strain of 29% ± 3%. Moreover, this alloy showed superb antibacterial activity against Staphylococcus aureus, in vitro osteogenic bioactivity, and biocompatibility toward MC3T3-E1 pre-osteoblast cells, and also effective antitumor activity against MG63 osteosarcoma cells. In the rat jaw defect model, this alloy showed complete biosafety and exceptional osteogenic properties. Overall, the Fe-15Mn-0.6Se alloy is a promising biodegradable bone implant material due to its unique mechanical and biofunctional properties.

OBJECTIVE:To fabricate personalized color-gradient dental lithium disilicate (LD) glass-ceramics by integrating computer-assisted color matching (CCM) with vat photopolymerization (VP). METHODS:The particle size and elemental composition of zirconium silicate (ZrSiO₄)-based pigments were evaluated using laser diffraction and energy-dispersive X-ray spectroscopy analysis, respectively. 45 vol% resin-based slurries doped with Fe-Pr-V/ZrSiO₄ pigments were prepared. The rheological behavior and exposure parameters of monochromatic gradient-concentration slurries were analyzed using shear-rate sweep and working-curve methods. Diffuse-reflectance spectroscopy was used to establish a CCM database and evaluate the color-matching accuracy of LD based on the VITA 3D-Master shade guide. The sintering behavior of five LD ceramic shades (1M2-5M2) was evaluated using thermogravimetric analysis, differential scanning calorimetry and X-ray diffraction, and their densities were determined using porosity analysis. The mechanical properties of the five classical shades of LD ceramics were evaluated via flexural strength testing, Weibull modulus analysis, fracture-toughness testing, Vickers indentation, and nanoindentation. A color-gradient maxillary central incisor crown was fabricated and its 3D accuracy was evaluated. RESULTS:Pigment particle sizes ranged from 5.9 to 8.9 μm with no interfacial defects in the LD matrix. Slurry viscosities at 50 °C were 2.3-2.5 Pa·s, while the red slurry required the highest exposure energy (12.2-16.7 mJ/cm²). Among the 26 predicted shades, 24 showed ΔE*ab < 3.7. After sintering, the relative density of the LD exceeded 99.5%. The LD specimens exhibited flexural strength of 380-428 MPa, fracture toughness of 2.94-3.50 MPa m¹ ᐟ², Weibull modulus > 10, Vickers hardness of 630-660 HV, and elastic modulus of 104-107 GPa. The color-gradient crown showed a root mean square deviation of 86.2 ± 5.7 μm. SIGNIFICANCE:This study demonstrates the integration of CCM and VP to fabricate color-gradient LD restorations, providing a precise and personalized strategy for esthetic dental application.

OBJECTIVES:To fabricate a zinc phosphate (ZnP) coating on 3 mol% yttria-stabilized tetragonal ZrO2 polycrystal (3Y-TZP) with enhanced mechanical strength, adhesion, cytocompatibility, antibacterial activity, and osteogenic performance, this study offers a new approach for improving dental implants. METHODS:The ZnP coating was synthesized on a substrate via hydrothermal treatment (150-250 ℃, 3 h) using a solution of zinc oxide, phosphoric acid, and nitric acid. The coated samples were characterized in terms of physicochemical properties, adhesion strength, flexural strength, and fracture morphology. Cellular responses, including viability, proliferation, and osteogenic differentiation, were assessed using CCK-8 assay, live/dead staining, phalloidin staining, alkaline phosphatase/Alizarin Red S assays, and real-time PCR. Antibacterial properties were evaluated based on colony-forming unit counts and bacterial adhesion assays in a rat subcutaneous infection model. Finally, in vivo bone formation and biosafety were analyzed by micro-computed tomography and histological examination after implantation. RESULTS:Increasing the hydrothermal temperature improved the coating thickness, roughness, wettability, and mechanical stability. The ZP-250 sample exhibited a 5B adhesion strength, which significantly enhanced MC3T3-E1 cell proliferation, osteogenic differentiation, mineralization, and gene expression. Moreover, it demonstrated strong antibacterial effects against S. aureus and E. coli, promoted osseointegration, and showed full biosafety in a jaw defect model. SIGNIFICANCE:The ZnP coating markedly improved the bioactivity of 3Y-TZP, addressing the challenge of bioinertness in dental implants. This innovation enhances long-term stability and clinical success, showing promising potential for clinical application.

Biodegradable zinc (Zn) alloys are promising candidates for bone implants due to their suitable degradation rate and inherent bioactivity. However, current Zn alloys require enhancement of their mechanical properties and biological functions through alloying and thermomechanical processing. Herein, we report the outstanding mechanical properties, corrosion, biocompatibility, and biofunctionalities of hot-rolled (HR) and hot-extruded (HE) Zn-4Ag-0.4Sr (ZAS) alloy in comparison with those of Zn-4Ag (ZA) for biodegradable orthopedic fixation. The HE ZAS sample exhibited the optimal balance of mechanical properties, including ultimate tensile strength of 318.0 MPa, tensile and compressive yield strengths of 257.3 MPa and 343.3 MPa, respectively, elongation at break of 22.3%, and Vickers and Brinell hardness values of 116.7 HV and 105.7 HB, respectively, satisfying the mechanical requirements for bone-implant applications. Nanoindentation identified the SrZn13 phase as a key reinforcement. The HE ZAS alloy exhibited the highest electrochemical corrosion rate of 614 μm/y and the highest degradation rate of 39.7 μm/y after 30 days of immersion, as well as the best biotribological performance in Hanks' solution, among all ZA and ZAS samples. Biologically, extracts of the HE ZAS alloy enhanced osteoblast viability, promoted angiogenesis in HUVECs, and stimulated osteogenic differentiation and mineralization in hBMSCs. Furthermore, the HE ZAS alloy displayed higher antibacterial efficacy against S. aureus in both in vitro and in vivo models while maintaining high biosafety. These results collectively indicate that the HE ZAS alloy is a promising candidate for next-generation biodegradable orthopedic-fixation devices, offering a notable balance of mechanical integrity, controllable degradation, and multifunctional bioactivity. STATEMENT OF SIGNIFICANCE: This work reports the notable mechanical performance, controlled corrosion, enhanced biotribological behavior, and multifunctional bioactivity of the hot-extruded Zn-4Ag-0.4Sr (HE ZAS) alloy for biodegradable orthopedic fixation devices. The HE ZAS alloy exhibits an optimal strength-ductility balance, with an ultimate tensile strength of 318.0 MPa, tensile yield strength of 257.3 MPa, and 22.3% elongation, satisfying the mechanical requirements for bone implants. The alloy also demonstrates the highest electrochemical corrosion rate (614 μm/y), degradation rate (39.7 μm/y), and biotribological performance among the tested alloys. Biologically, the alloy enhances osteoblast viability, stimulates angiogenesis and osteogenic differentiation, and exhibits effective antibacterial activity against Staphylococcus aureus both in vitro and in vivo, while maintaining complete biosafety.

Background Lithium disilicate glass-ceramics (LDGCs) have become one of the most widely used dental prosthesis materials in clinical practice due to their excellent esthetics, biocompatibility, and enamel-like wear resistance. However, their inherent brittleness, limited mechanical strength, and progressive wear under long-term service have restricted their application in high-stress posterior regions. Herein, this study aims to develop zirconia (ZrO2)-reinforced LDGCs and systematically investigate the effects of ZrO2 content on microstructure evolution and mechanical, translucency, tribological, and biological performance. Methods ZrO2-reinforced LDGCs (LDGCxZ, where x = 0, 2, 4, 6 mol%, designated as LDGC, LDGC2Z, LDGC4Z, and LDGC6Z) with varying ZrO2 contents were fabricated via a melting-derived powder processing route combined with digital light processing, debinding, and sintering. The LDGCxZ samples were systematically characterized for their microstructural evolution, mechanical properties, translucency, tribological behavior, and biological performance through biaxial flexural strength testing, aging resistance testing, Weibull two-parameter distribution analysis, Vickers hardness testing, fracture toughness analysis, nanoindentation testing, and tribological evaluation. Furthermore, hemocompatibility, cytocompatibility, and in vivo biological responses were assessed using hemolysis assays, CCK-8 assays, live/dead staining, phalloidin staining, subcutaneous implantation in a rat model, and comprehensive biosafety evaluation. Results 4 mol% ZrO2 doping optimally refines the crystalline structure, creating a homogeneous dual-phase of Li2Si2O5 and Li2SiO3 that effectively minimizes internal defects, while excessive doping (6 mol%) leads to abnormal grain growth and porosity formation. Impressively, the sintered LDGC4Z sample (4 mol% ZrO2) exhibited exceptional comprehensive properties: a flexural strength of ∼294 MPa, fracture toughness of ∼4.1 MPa m1/2, elastic modulus of ∼111.4 GPa, and Vickers hardness of ∼644 HV, and a 150% enhancement in the translucency parameter, alongside superior anti-aging resistance and tribological behavior closely matching that of natural enamel. The LDGC4Z sample also confirmed excellent hemocompatibility, favorable cytocompatibility with human gingival epithelial cells, and stable tissue integration in subcutaneous implantation models. Collectively, the LDGC4Z sample exhibited balanced improvements in mechanical properties, translucency, tribological resistance, and biological safety, while suppressing LTD through microstructural refinement, stress engineering, and crystallization control.SignificanceThis study overcomes the limitations of conventional processing routes by integrating DLP 3D printing technology with a ZrO2 compositional regulation strategy within the LDGC system. A novel LDGC system that combines printability, microstructural controllability, and mechanical compatibility was successfully established, providing an essential theoretical foundation and process framework for the development of high-performance LDGC materials for dental restorations.

Lithium disilicate glass-ceramics (LDGCs) are widely employed in dental aesthetic restorations; however, their application is constrained by insufficient fracture toughness and the inefficiencies inherent in conventional milling processes. This study investigated the additive manufacturing of LDGCs doped with Bspodumene to address these limitations. LDGCs doped with 0, 2.5, 5, 10, and 20 wt.% B-spodumene were prepared via additive manufacturing followed by heat treatments, and their thermal behavior, density, phase composition, microstructure, mechanical properties, and molding accuracy were evaluated. The results indicate that as the doping level of B-spodumene increased, the porosity, crystallinity, strength, and toughness initially improved and then decreased, with the most significant enhancement observed at 2.5 wt.%. The size of lithium disilicate crystals decreased as the doping of B-spodumene increased. Notably, the 2.5 wt.% doped composites demonstrated a toughness of 3.4 f 0.2 MPa m1/2 , attributed to the secondary phase toughening mechanism of B-spodumene. Additionally, these B-spodumene-doped LDGCs exhibit excellent molding accuracy. These findings suggest that B-spodumene-doped LDGCs possess good mechanical properties and machinability, showing promising potential for dental restorative applications. (c) 2025 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

OBJECTIVES:This study aims to improve the densification and strength of additively manufactured lithium disilicate glass-ceramics (LDGCs) for dental restorations by introducing a β-spodumene-lithium metasilicate (LM)-amorphous silicon dioxide (A-SiO2)-glass system. METHODS:Precursor slurries with varying ratios of β-spodumene, LM, and A-SiO2 were shaped using digital light processing and subsequently sintered without applied pressure. The resulting LDGC samples were systematically evaluated in terms of density, porosity, phase composition, microstructure, mechanical properties, fracture morphology, and molding accuracy. RESULTS:The combined addition of β-spodumene and LM significantly reduced porosity, promoted densification and crystallinity, and produced a uniform interlocked microstructure. In contrast, the introduction of A-SiO2 facilitated the transformation of LM into lithium disilicate, but increased porosity and defects by impeding densification. The optimized β-spodumene/LM/glass ternary system achieved a maximum flexural strength of ∼332.5 MPa and a fracture toughness of ∼2.3 MPa·m1/2, while exhibiting hardness and elastic modulus comparable to natural enamel. Moreover, crown manufacturing demonstrated high molding accuracy. SIGNIFICANCE:The synergistic addition of β-spodumene and LM effectively enhances densification and strength in additively manufactured LDGCs, establishing a promising material system for high-load aesthetic restorations.

Background: Vascularization is essential for bone regeneration. Conventional guided bone regeneration membranes (GBRMs) have poor mechanical performance and insufficient pro-angiogenic/osteogenic activity, limiting the repair of complex alveolar bone defects. Methods:This study fabricated a biodegradable electrospun DFO/PCL/Gel modified Zn-Sr alloy mesh (ZSPD), and systematically evaluated its mechanical properties, degradation behavior, drug release performance, biocompatibility, pathway regulation, antibacterial ability and bone repair effect via in vitro and in vivo experiments. Findings:ZSPD possessed superior mechanical strength than commercial collagen membranes. The coating stabilized alloy degradation and achieved sustained DFO release. It promoted angiogenesis via HIF-1α pathway and osteogenesis via PI3K-Akt pathway, exerted excellent antibacterial activity against Staphylococcus aureus, and efficiently accelerated new bone formation in rat mandibular defects. Interpretation:The multifunctional ZSPD with favorable mechanical, degradable, bioactive and antibacterial properties is a promising advanced GBRM for alveolar bone defect repair.

This study presents the fabrication of beta-type Ti-28Nb-35.4Zr (TNZ) and graphene nanoplatelet (GNP)-reinforced TNZ composites (0.1 and 0.2 wt.%) via direct metal deposition (DMD) for orthopedic implant applications. The effects of GNP addition on microstructure, mechanical strength, tribological behavior, corrosion resistance, and cytocompatibility were systematically evaluated. All DMD-processed samples primarily exhibited beta-phase, while GNP incorporation promoted alpha '' martensite formation due to oxygen uptake during processing. The 0.1 wt.% GNP addition refined the grain structure, enhancing compressive yield strength by 16% (863 MPa) and maintaining high ductility with a maximum strain >55%. Hardness increased by 17% for the TNZ-0.1GNP composite, which had the lowest wear volume (0.03 & micro;m(3)) and minimal debris formation. Electrochemical testing in Hanks' balanced salt solution revealed enhanced corrosion resistance for TNZ-0.1GNP with a corrosion rate of 3.88 & micro;m y(-1) due to synergistic passivation and barrier effects. The reduced water contact angle (74 degrees +/- 5 degrees) indicated improved hydrophilicity and favorable surface energy for biointeractions. Furthermore, human osteoblast-like SaOS2 cells showed thriving adhesion, proliferation, and complete surface coverage on TNZ-0.1GNP after 7 days of culture. Overall, DMD-processed TNZ-0.1GNP composite exhibited promising mechanical, wear resistance, corrosion and biocompatible performance as load-bearing orthopedic implant materials.

The 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) ceramic has potential dental restoration applications due to its sufficient mechanical strength, high esthetic potential, and biocompatibility. Nevertheless, the conventional clinical processing of 3Y-TZP ceramic has a significant amount of material waste, high tool wear, and the possible formation of microcracks. In this study, alumina whisker (Al(2)O(3)w)-reinforced 3Y-TZP ceramic composites were prepared using the stereolithography technology followed by sintering for dental crown applications. This study aimed to address current manufacturing defects in dental ceramics by fabricating tough, strengthened zirconia ceramics using 3D printing technology. The results indicate that the grain size and distribution homogeneity of the ZrO2 phase, mechanical properties, and hardness of the 3Y-TZP/Al(2)O(3)w specimens were better than those of the 3Y-TZP specimen, while the relative density showed a decrease with an increase in Al(2)O(3)w contents. The 3Y-TZP/7.5 % Al(2)O(3)w composite showed the best mechanical performance with a flexural strength of similar to 863.0 MPa, a Vickers hardness of similar to 13.2 GPa, and a fracture toughness of similar to 6.6 MPa m(1/2), which is about 13.1 %, 9.7 % and 25.1 % higher than those of 3Y-TZP specimens. The low-temperature degradation testing revealed that the addition of the reinforcement Al(2)O(3)w improved the anti-aging properties of 3Y-TZP specimens. Further, the 3Y-TZP/Al(2)O(3)w ceramic composite samples showed good cytocompatibility with a cell viability of higher than 90 % toward L929 cells and prototyping properties.

Zinc (Zn)-based composites are promising biodegradable bone-implant materials because of their good biocompatibility, processability, and biodegradability. Nevertheless, the low interfacial bonding strength, coordinated deformation capacity, and mechanical strength of current Zn-based composites hinder their clinical application. In this study, we developed a biodegradable in situ 4Mg2Ge/Zn-0.3Cu-0.05P composite (denoted ZMGCP) via phosphorus (P) modification and hot-rolling for bone-implant applications. The mechanical properties, corrosion behavior, biotribological performance, in vitro cytocompatibility and osteogenic differentiation, and in vivo osteogenesis and osteointegration of the as-cast (AC) and hot-rolled (HR) ZMGCP samples were systematically evaluated and compared to those of 4Mg2Ge/Zn-0.3Cu (denoted ZMGC). The primary and eutectic reinforcement Mg2Ge phases formed during solidification were refined after P modification and hot-rolling. The HR ZMGCP exhibited the best tensile properties among all the samples with an ultimate tensile strength of 288.9 MPa, a yield strength of 194.5 MPa, and an elongation of 17.7 %. The HR ZMGCP showed the lowest corrosion rate of 336 μm/a, 186 μm/a, and 61.7 μm/a as measured by potentiodynamic polarization, electrochemical impedance spectroscopy, and immersion testing, respectively, among all the samples in Hanks’ solution. The HR ZMGCP also showed higher biotribological resistance than its ZMGC counterpart. The HR ZMGCP exhibited the highest in vitro cytocompatibility, the best osteogenesis capability and angiogenesis property among the HR samples of pure Zn, ZMGC, and ZMGCP. Furthermore, the HR ZMGCP displayed complete in vivo biocompatibility, osteogenesis, osteointegration capability, and an appropriate degradation rate, showing significant potential for a biodegradable bone-implant material.

Iron/zinc (Fe/Zn) composite may offer an accelerated degradation rate for bone-implant applications due to the large interfaces between its different constituents. Nevertheless, it is challenging to fabricate a biodegradable composite that exhibits an appropriate aggregation of the mechanical, corrosion, and biological properties required for bone fixation. In this study, we developed an innovative process to fabricate a composite of Fe/Zn via hot extrusion of Zn powder-infiltrated Fe foam for biodegradable bone-fixation applications. This hot-extruded (HE) Fe/Zn sample exhibited the following: ultimate tensile strength 316.3 MPa, tensile yield strength 269.0 MPa, elongation 11.5 %, compressive yield strength 275.3 MPa, and Brinell hardness 77.0 HB, all significantly better than the respective values of its pure Zn counterpart. The HE Fe/Zn also had: electrochemical corrosion rate 2466 μm/a and degradation rate 135.7 μm/a in Hanks' solution. The HE Fe/Zn extract at 12.5 % concentration showed satisfactory cytocompatibility, angiogenicity, osteogenic differentiation, and mineralization capabilities in vitro. The angiogenesis mechanisms of the HE Fe/Zn sample included Jak-STAT and Jak-PI3K-Akt pathways. Furthermore, the HE Fe/Zn sample displayed complete in vivo antibacterial, anti-inflammatory, angiogenic, osteogenic, osteointegration capabilities, and a suitable degradation rate in rat subcutaneous infection and femur defect models.

Aim or purpose: Lithium disilicate glass-ceramics (LDGCs) are widely employed in dental aesthetic restorations; however, their application is constrained by insufficient fracture toughness and the inefficiencies inherent in conventional milling processes. This study investigated the additive manufacturing of LDGCs doped with β-spodumene to address these limitations. Materials and methods: Lithium disilicate glass-ceramics with 0, 2.5, 5, 10, and 20 wt% β-spodumene were prepared via additive manufacturing followed by controlled multi-step heat treatments. The thermal behavior, porosity, density, phase composition, microstructure, mechanical properties, and molding accuracy were systematically evaluated. Results: The results indicate that as the doping level of β-spodumene increased, the apparent and internal porosity, crystallinity, flexural strength, fracture toughness and elastic modulus initially improved and then decreased, with the most significant enhancement observed at 2.5 wt%. The size of lithium disilicate crystals decreased as the doping of β-spodumene increased. Notably, the 2.5 wt% doped composites exhibits higher fracture toughness than current commercial glass-ceramics. Fracture analysis shows that the doping of β-spodumene increases the transgranular and intergranular fractures inside the glass-ceramics, thus increasing the toughness of the composite material through the second phase toughening mechanism. Additionally, these β-spodumene-doped LDGCs exhibit excellent molding accuracy. Conclusions: These findings suggest that β-spodumene-doped LDGCs possess good mechanical properties and machinability, showing promising potential for dental restorative applications.