Search Results (938)

Background: Metallic orthopedic implants face persistent clinical challenges that have proved resistant to incremental conventional development. Machine learning and artificial intelligence offer a complementary paradigm for navigating the high-dimensional design spaces governing implant performance, yet the literature remains fragmented across disciplinary silos with no comprehensive synthesis spanning the full development pipeline. Methods: A structured database search of PubMed/MEDLINE, Embase, and Cochrane (executed May 2026), supplemented by hand-searching of reference lists, identified 33 primary studies organized across five sequential domains: alloy composition discovery, additive manufacturing process–property optimization, lattice and porous structure design, surface engineering and coatings, and corrosion and wear prediction. Results: Across all five domains, machine learning approaches, including random forests, convolutional neural networks, Bayesian optimization, generative adversarial networks, physics-informed neural networks, and autonomous multi-agent platforms, have accelerated property prediction and design space exploration beyond experimental or simulation-based methods. Shared barriers to translation include small, heterogeneous datasets, reliance on internal rather than external validation, limited interpretability, and the absence of regulatory frameworks for AI-assisted device design. Representative performance included modulus predictions within ~4 GPa of first-principles values, ML-designed alloys reaching ~42.7 GPa (versus 103–120 GPa for Ti-6Al-4V), property prediction R² often above 0.90 (up to 0.96–0.9991), 98.3% corrosion severity classification accuracy, and acceleration from a roughly fivefold reduction in finite element simulations to surrogates compressing days into minutes. Conclusions: Addressing these limitations will require open standardized databases linking materials parameters to registry-level clinical outcomes, prospective clinical validation studies, and coordinated engagement between researchers, industry, and regulatory agencies. Full article

The release of aluminum (Al) and vanadium (V) ions represents a critical concern limiting the long-term performance and biocompatibility of Ti6Al4V-based permanent orthopedic implants. This study focuses on improving the corrosion resistance of Ti6Al4V alloys through the application of a novel organic–inorganic ZnO nanocoating. In addition, the present study investigated the influence of substrate roughness on surface morphology, microhardness, and wettability characteristics. Xanthan gum (XG) and celite (CE) were utilized as a biopolymeric–ceramic matrix for the ceramic–biopolymer-assisted synthesis of ZnO nanoparticles (ZnO NPs) through ultrasonication, which was subsequently followed by deposition onto Ti6Al4V substrates with varying surface roughness (Ra) achieved through controlled turning. The synthesized XG/CE-ZnO NPs exhibited a uniform spherical morphology with an average particle size of nearly 50 nm and a hexagonal wurtzite crystalline structure, as confirmed by TEM, XRD, and FTIR analyses. Contact angle (CA) measurements indicated that wettability increased with higher Ra, while SEM with energy-dispersive X-ray spectroscopy characterization revealed morphology transitions from smooth, homogeneous coatings to agglomerate, star-like nanostructures as Ra increased. Electrochemical testing in Ringer’s solution demonstrated a significant improvement in corrosion resistance after coating, with protection efficiencies ranging from 95.18% to 98.48%, particularly for smoother substrates. Although increased Ra may enhance coating adhesion through mechanical interlocking, smoother substrates promote the formation of more homogeneous coatings, resulting in superior corrosion protection. These results demonstrate the significant influence of substrate topography in enhancing the functional performance of biocompatible ZnO nanocoatings, providing valuable insights for the surface engineering of metallic implants. Full article

Background/Objectives: One-piece (monoblock) dental implants are increasingly used, particularly in patients with limited bone availability. Prosthetic alignment is often achieved via plastic deformation of the titanium implant. This study aimed to evaluate the impact of such deformation-induced residual stress on the corrosion resistance of these implants. Methods: Two types of monoblock dental implants (spherical “S” and Mag-Conical “M”) were subjected to controlled plastic deformation. Residual stress was quantified by X-ray diffraction using the Bragg–Brentano method. Electrochemical behavior was evaluated by measuring the open-circuit potential (E_OCP) and performing potentiodynamic polarization tests in phosphate-buffered saline (PBS) at 37 °C. Metal ion release (Ti, V, Al) was quantified by inductively coupled plasma mass spectrometry (ICP-MS) at specific immersion time points. Surface morphology and corrosion features were examined by scanning electron microscopy (SEM). Results: Residual stress values increased significantly after plastic deformation. The open-circuit potential (E_OCP) shifted towards more electronegative values in both implant designs as deformation-induced residual stresses increased. The E_OCP values shifted from −0.099 V to −0.227 V in the S design and from −0.115 V to −0.141 V in the M design, comparing the as-received condition with the deformed state, respectively. Potentiodynamic tests showed an increase in corrosion rate from 0.0021 mm/year for the original implants to 0.0156 mm/year for the deformed ones. Surfaces in the stressed regions exhibited a high density of corrosion pits, indicating localized electrochemical degradation. Deformed dental implants also exhibited higher ion release, particularly of titanium and vanadium, with higher levels observed in implants with greater residual stress and lower corrosion resistance. In the deformed regions, the release of titanium and vanadium ions into the surrounding medium was nearly five-fold higher. Conclusions: Plastic deformation of monoblock dental implants is associated with reduced corrosion resistance. Increased residual stress correlates with enhanced electrochemical degradation and ion release, which may have relevant implications for implant selection and clinical placement. Full article

Copper alloying of Ti6Al4V via liquid-phase sintering (LPS) is a promising route to enhance densification and mechanical properties for biomedical implants. This study investigates the effect of sintering temperature (900–1100 °C) on the densification, microstructure, and electrochemical behavior of Ti6Al4V–20 wt.% Cu composites. Samples were fabricated via pressureless sintering, maintaining a constant relative green density of 72.7%. The results show that the relative density increased progressively from 78.6% at 900 °C to 98.1% at 1100 °C. Microstructural analysis revealed a transition from fragmented Ti-Cu dendritic structures to refined globular intermetallic, with enhanced copper diffusion into the α-Ti matrix above 1000 °C, accompanied by the formation of TiCu and Ti₂Cu intermetallic phases. Correspondingly, microhardness increased systematically from 313 HV to 473 HV, correlated with reduced porosity and intermetallic reinforcement. Electrochemical tests in Ringer’s solution indicated that while higher temperatures improve structural integrity, the distribution of Cu-rich phases significantly influences corrosion kinetics. These findings demonstrate that sintering at 1100 °C optimizes the densification–microstructure relationship, providing a technical basis for the development of high-performance Ti-based composites. Based on previous studies of Ti–Cu systems, these materials may exhibit antibacterial activity, although no biological or antibacterial tests were performed in the present work. Full article

Cobalt–chromium (CoCr) alloys have gained significant importance in the field of medical implants due to their outstanding combination of mechanical strength and excellent wear and corrosion resistance. Compared with other state-of-the-art materials, such as stainless steel or titanium, CoCr alloys typically exhibit superior fatigue strength, which is particularly advantageous for implants and components exposed to long-term repetitive loading. The present study investigates the feasibility of using commercially available CoCr alloy powders in the Laser Powder Bed Fusion (PBF-LB/M) process for the fabrication of biomedical implants. Microstructural characterization of the PBF-LB/M-manufactured CoCr samples revealed a dense, refined cellular–dendritic microstructure with a high degree of densification, characteristic of the rapid solidification associated with the PBF-LB/M process. The evaluation of mechanical performance, wear behavior, and corrosion resistance provides valuable insights into the suitability of these alloys for biomedical applications, especially in the design of complex implants requiring enhanced durability and long-term reliability. Furthermore, compression testing highlighted the influence of layer orientation on mechanical properties, emphasizing the importance of strategic prototyping and building orientation selection in the PBF-LB/M process. Tribological behavior assessed under dry sliding conditions demonstrated a significantly reduced coefficient of friction and lower wear rate compared to a conventional 316L stainless steel, which is frequently used in similar applications. Corrosion resistance was evaluated by potentiodynamic polarization measurements in Ringer electrolyte, showing that the PBF-LB/M-fabricated CoCr samples exhibit good corrosion resistance in environments resembling physiological fluids. Overall, the PBF-LB/M technique represents a promising manufacturing route for next-generation CoCr biomedical implants, particularly for orthopedic and dental applications. Beyond the biomedical field, the findings of this study also support the potential extension of PBF-LB/M-processed CoCr alloys to industrial sectors requiring high wear and corrosion resistance, including aerospace and automotive applications. Full article

Magnesium alloys are considered to be the third generation of biomaterials used in biomedical applications to promote bone tissue regeneration. Due to their Young’s modulus being similar to that of human bone and their release of magnesium ions that are antimicrobial and osteoinductive, these biomaterials not only promote bone regeneration, minimize the effects of stress shielding and reduce the risk of infection, but also their exceptional biocompatibility and bioresorbability eliminate the need for a second surgery to remove the implant. However, because magnesium has poor corrosion resistance, without different coatings and surface treatments, the implant can be compromised before the bone is fully healed. With additive manufacturing (AM) as a revolutionary technology, the one-size-fits-all approach can be replaced by fully personalized medicine, in which complex shapes can be created, designed, and processed with unique parameters for each patient. However, 3D printing of Mg-based devices remains particularly challenging due to magnesium’s high chemical reactivity, combustion risk, and low vaporization temperature, challenges that are further compounded when alloying elements are introduced. This review addresses this gap by critically examining the properties, corrosion behavior, and bio-medical performance of Mg and its alloys, with a focused analysis of selective laser melting (SLM) and wire arc additive manufacturing (WAAM) as key fabrication methods. The influence of processing parameters, microstructural defects, and alloy composition on the final properties of AM-fabricated Mg components is systematically discussed, alongside current limitations and prospective strategies toward their clinical translation. Full article

Titanium and its alloys are cornerstone biomaterials due to their high strength-to-weight ratio, excellent fatigue and corrosion resistance, biocompatibility, and ability to osseointegrate with bone. Their relatively low elastic modulus compared to stainless steels and Co–Cr alloys further enhances their suitability for biomedical applications. Performance is continually improved through alloy design (tailoring α and β phases), advanced manufacturing methods such as CNC machining and additive manufacturing, and surface engineering approaches. In particular, the formation of a stable TiO₂ layer promotes corrosion resistance and cell attachment, while coatings and nanotexturing enhance osseointegration and provide antibacterial functionality. These attributes enable widespread use in orthopedic, dental, and cardiovascular implants. Emerging developments include smart implants with embedded sensors, multifunctional surfaces, and data-driven alloy design, aiming to further optimize mechanical performance, biological response, and long-term reliability. This review summarizes the processing techniques, properties, applications, and recent advances in titanium-based biomaterials. Full article

This study investigates titanium oxynitride (TiO_xN_y) coatings deposited by reactive magnetron sputtering on 316L stainless steel substrates in an Ar–N₂–O₂ gas mixture at a fixed N:O ratio of 1.6. The coatings were deposited under three reactive magnetron sputtering regimes with Ar flow rates of 33, 28, and 26 sccm and corresponding substrate biases of −50, −100, and −150 V, respectively, while the N₂ and O₂ flow rates were kept constant at 10 and 6 sccm. The coatings exhibited a dense microstructure, with thicknesses ranging from 2.13 to 5.51 μm. X-ray diffraction analysis revealed the formation of a multiphase structure comprising TiN, TiO_xN_y, and TiO. The deposition regime had a significant influence on the functional properties of the coatings. The lowest friction coefficients (µ ≈ 0.26–0.28) and stable tribological behavior were characteristic of the Ar26 sample. The highest corrosion resistance was observed for the Ar28 sample, with a corrosion current density of i_corr = 2.82 × 10⁻⁷ A/cm² and a corrosion rate of v_corr = 0.00573 mm/year. All coatings exhibited hydrophilic surface behavior, with contact angles of 50–57°, which may be relevant for further evaluation in biomedical surface applications. Thus, the structure and functional properties of TiO_xN_y coatings can be regulated by selecting an appropriate deposition regime, including the Ar flow rate, relative reactive gas fraction, and substrate bias. However, additional biological tests, including cytotoxicity, hemocompatibility, endothelialization, and platelet adhesion studies, are required before conclusions about vascular implant applicability can be made. Full article

Background: Biodegradable implants manufactured from Mg-based alloys are one of the most commonly used in orthopedics. However, their overall clinical acceptance is influenced by their fast corrosion speed and hydrogen emission. Based on an innovative manufacturing route previously described, this study introduces a preliminary proof-of-concept for a Gemini-assisted Digital Twin (Gemini-DT),which is an AI-augmented in silico framework designed to consider a MgF₂ conversion coating on the implant surface and to model the synchronization of the degradation process with new bone formation. Methods: Based on the integration of experimental data for Mg-Nd and Mg-Zn alloys and by considering the implant geometry and coating formation, we developed, in collaborative work with LLM Gemini 1.5 Flash (Google), a four-module cognitive framework (surface thermodynamic synergy (Module 1), degradation analysis and alloy extract concentration management (Module 2), micro-channel fluidics and mechanical stability (Module 3), and bio-mechanical synchronization and regenerative evaluation (Module 4)) to evaluate simulated implant behaviors). Results: Using a 10,000 iteration Monte Carlo stability simulation, the model demonstrated a potential 12% reduction in false-negative design screening errors compared to rigid rule-based systems, achieving strong internal decision consistency in sustaining the mandated parametric compliance window. Computational verification supports the projected biocompatibility trends of Mg-Zn alloys, as previously demonstrated in our in vivo studies. Conclusions: Our research leads to a consistent computational architecture dedicated to Mg-based implants and offers a robust platform for virtual design and optimization. These observations suggest that the developed model can recover viable designs, whereas traditional linear models may reject them. Full article

Background/Objectives: Titanium alloy Ti₆Al₄V remains the gold standard in dental implantology due to its excellent mechanical properties, corrosion resistance, and biocompatibility. However, implant-associated infections and insufficient osseointegration continue to represent major clinical challenges, mainly related to bacterial biofilm formation and suboptimal surface–tissue interactions. Biofilm formation refers to the adhesion, accumulation, and growth of microbial communities embedded within a self-produced extracellular polymeric matrix on implant surfaces, which contributes to bacterial persistence and resistance to host defense mechanisms. This review aims to critically evaluate recent advances in multifunctional bioceramic coatings for dental implants, with a particular focus on zirconia (ZrO₂)-based systems and their antibacterial mechanisms. Methods: A structured literature analysis was conducted using major scientific databases including PubMed, Scopus, and Web of Science, focusing mainly on studies published between 2015 and 2025 related to CaP, Ag, and ZrO₂-based coatings for dental implants. The review examines their physicochemical properties, antibacterial strategies, ion release behavior, and biological responses, including osteogenic activity and biofilm inhibition. Particular attention is given to hybrid systems integrating multiple functional phases. Results: CaP coatings exhibit excellent osteoconductivity and promote early osseointegration but show limited intrinsic antibacterial activity. Ag-based coatings provide strong broad-spectrum antimicrobial effects through controlled Ag⁺ ion release, although concerns regarding cytotoxicity and dose-dependent responses remain. ZrO₂ coatings significantly enhance corrosion resistance and surface stability, while their antibacterial performance can be improved through nanostructuring, laser surface modification, and ionic doping. Hybrid Ag–CaP–ZrO₂ coatings demonstrate improved antibacterial activity, enhanced corrosion resistance, and better regulation of ion release kinetics and osteogenic response compared with single-component coating systems. Conclusions: Multifunctional bioceramic coatings represent a promising strategy for improving the performance of dental implants and addressing the dual challenge of infection control and tissue integration. However, challenges remain regarding long-term stability, controlled ion release, and limited clinical validation. Future research should focus on the development of smart, stimuli-responsive coatings and standardized evaluation protocols to facilitate clinical translation. Full article

Poly(3,4-ethylenedioxythiophene) (PEDOT)-based gels have emerged as a prominent class of functional conductive materials, owing to their unique electromechanical coupling characteristics that integrate electrical functionality and mechanical adaptability. This review systematically elucidates the electromechanical properties of PEDOT-derived gels—defined as the synergistic response of electrical behaviors (conductivity, carrier mobility, electrochemical stability) and mechanical performances (flexibility, stretchability, tensile strength, bending resistance)—under mechanical deformation, as well as their mutual regulatory mechanisms. Focusing on how preparation processes and structural regulation modulate these electromechanical properties, this work first introduces the development history, intrinsic conductive mechanisms, and inherent electromechanical characteristics of PEDOT. It then systematically summarizes mainstream synthesis methods, analyzing their effects on balancing mechanical flexibility and electrical conductivity. Addressing the brittleness and poor electromechanical stability of pure PEDOT, this review further explores composite synergistic mechanisms with conductive/non-conductive polymers, metallic materials, inorganic nanoparticles, and biomaterials, clarifying how interfacial interactions optimize mechanical deformability while preserving or enhancing electrical performance. Finally, it summarizes the applications of PEDOT-based composites in electromechanically compatible fields including flexible sensing, micro/nano patterning, implantable biomedicine, anti-corrosion protection, and energy storage. This review aims to clarify the connotation of PEDOT’s electromechanical properties, refine the focus of relevant research, and provide a theoretical basis for designing high-performance PEDOT-based gels with balanced electromechanical properties. Full article

To develop novel biodegradable magnesium alloys with suitable corrosion resistance and mechanical properties for orthopedic applications, this study investigated the microstructure, mechanical properties, corrosion behavior and wear resistance of as-cast and near-solidus heat-treated Mg-3Zn-0.3Mn alloys with and without Gd/Nd additions (RE-free, 1Gd, 1Gd1Nd). Rare earth addition refined the grains and transformed the secondary phase from Mg₇Zn₃ to the W-phase (Mg₃RE₂Zn₃). The as-cast 1Gd1Nd alloy showed the finest grains, highest hardness (51.3 HB), best tensile strength (189.38 MPa), lowest corrosion rate (2.80 mm/y) and lowest wear rate (0.614 × 10⁻³ mm³/(N·m)). Near-solidus heat treatment slightly decreased hardness (1–3%) but significantly reduced corrosion rate (e.g., RE-free alloy from 3.61 to 2.78 mm/y) and wear rate. The heat-treated 1Gd1Nd alloy gave the best overall performance: corrosion rate 2.68 mm/y, tensile strength 213.71 MPa and elongation 12.96%. Gd promoted grain refinement and film stability, while Nd stabilized the W-phase, showing a clear combined addition benefit. Notably, the heat-treated RE-free alloy performed similarly to the as-cast 1Gd1Nd alloy, indicating that heat treatment can partially mimic rare earth addition. This work provides a baseline for precursor materials before further processing (e.g., extrusion) toward biodegradable implant applications. Full article

To address the severe wear and galvanic corrosion of TC4/Mg three-dimensional interpenetrating composites caused by the potential difference and hardness disparity between the two phases, this work proposes a hybrid surface modification strategy combining plasma electrolytic oxidation (PEO) with a self-assembled monolayer (SAM) doped with multi-walled carbon nanotubes (MWCNTs). A PEO ceramic coating was first grown in situ on the composite surface, followed by sealing modification using MWCNTs-containing SAM. The microstructure, phase composition, tribological behavior and potentiodynamic polarization curves of the coatings were systematically evaluated. The results show that the PEO coating is mainly composed of Mg₂SiO₄, MgO, MgF₂ and TiO₂, exhibiting a typical porous structure. After the MWCNTs-doped SAM composite modification, the nano-fillers and the molecular layer synergistically seal the micropores and cracks, and the surface transforms into a continuous and dense layered morphology. Wear tests reveal that the composite coating reduces the friction coefficient to 0.195 and decreases the wear volume by 93.53% compared with the bare composite. The “micro-roller bearing” effect and debris adsorption of MWCNTs significantly improve the wear resistance, and the dominant wear mechanism changes from abrasive wear to three-body wear. Electrochemical measurements show that the corrosion current density of the composite coating decreases from 2 × 10⁻⁴ A·cm⁻² (bare composite) to 1.401 × 10⁻⁹ A·cm⁻², i.e., a reduction by five orders of magnitude, with a protection efficiency of 99.99%. This is attributed to the physical barrier effect of the PEO coating and the synergistic sealing of defects, as well as the blocking of electron transfer by MWCNTs/SAM. The multi-level protection system of “PEO + MWCNTs + SAM” constructed in this work achieves a synergistic improvement in both wear resistance and corrosion resistance of the TC4/Mg two-phase interpenetrating composite, and holds promise for further investigation as an osseointegration implant material. Full article

Alumina is a long-used dental and medicinal biomaterial. It is considered one of the best jaw implant materials and has greater antibacterial resistance than titanium (Ti6Al-4V). 3D-printed alumina dental implants were tested in NaCl and Ringer’s solutions for electrochemical corrosion. In six studies, linear polarisation (LPR), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and SEM were used to assess, compare, and elucidate corrosion mechanisms in 3.5% NaCl solution and Ringer’s solution at 25 °C, 45 °C, and 65 °C. At 25–65 °C, alumina in NaCl had corrosion rates of 0.000016–0.000013 mm/yr. Polarisation resistance was good even in a chloride-rich environment at high temperatures, showing effective corrosion protection. The EIS test indicated that the alumina film’s excellent dielectric and insulating capabilities prevented deterioration of the alumina substrate in a concentrated chloride solution. The SEM showed no deep pits. Full article

Background/Objectives: Electrolytes used in in vitro corrosion testing critically determine the behavior inferred for metallic dental implants, yet formulations and their justifications are inconsistently reported across the literature. This review compiles and compares electrolytes employed to simulate the oral cavity and the bone–implant interface, linking their chemical composition to the corrosion mechanisms they target. Methods: This structured narrative review synthesized peer-reviewed literature on simulated electrolytes used for in vitro corrosion testing of metallic dental implants and implant-related alloys. Literature was identified using database searches and targeted reference screening, with emphasis on artificial saliva formulations, physiological simulated fluids, challenge chemistries, protein-containing media, hydrodynamic conditions, and microbiological models. Relevant formulations were standardized to grams per liter and grouped according to application domain and targeted corrosion mechanisms. Results: The analysis maps electrolyte selection to corresponding corrosion modes, including uniform dissolution, pitting, crevice, galvanic, and microbiologically influenced corrosion. Consolidated composition tables highlight how pH, halide concentration, calcium–phosphate balance, proteins, gas control, and flow conditions modify passive-film stability and metal-ion release. Dental-specific gaps are identified, notably the lack of a standardized fluoride–pH matrix and limited guidance for microbiome-integrated assays. Conclusions: Aligning electrolyte formulations with the research question enhances reproducibility and mechanistic interpretation. However, current in vitro corrosion data should be interpreted cautiously because quantitative links between simulated-fluid testing and clinical outcomes such as peri-implantitis, peri-implant bone loss, and implant failure remain insufficiently established. The adoption of shared reporting standards, dynamic programmable chemistries, and interoperable datasets may improve the translational value of future corrosion studies. Full article