Search Results (39)

The rapid development of implantable medical electronics requires robust biocompatible coatings capable of ensuring long-term stability in aggressive physiological environments. Although Grade 1 titanium is widely used for its excellent mechanical properties and corrosion resistance, active implants require defect-free insulating coatings to prevent electrical leakage and metal ion release. This study presents a systematic evaluation of Parylene C (P-C) thin films deposited by the Gorham chemical vapor deposition (CVD) process onto implant-grade titanium substrates. Four coating thicknesses (1, 5, 10, and 20 µm) were deposited and characterized using complementary chemical, morphological, optical, and mechanical techniques. Contact-angle measurements confirmed uniform hydrophobicity (90.56 ± 1.86°), while FTIR and EDX verified the characteristic chemical composition of P-C. Reflectometry, ellipsometry, and interferometry demonstrated excellent thickness control and deposition reproducibility. Pull-off testing showed high initial mechanical integrity, with detachment forces ranging from 52 to 73 N. However, accelerated PBS ageing (21 days at 90 °C) induced significant degradation, particularly for thicker coatings, reducing pull-off forces to 19–42 N. Likewise, thermal-shock cycling (−80 °C to +220 °C) caused severe interfacial damage, decreasing the required detachment force to approximately 5.5 N for 20 µm coatings because of extensive cracking and delamination. These results demonstrate that Parylene C provides excellent conformal coverage and chemical stability on titanium but that its durability is significantly affected by prolonged hydrothermal ageing and extreme thermal loading. This study provides practical guidelines for the design of reliable encapsulation systems for active implantable medical devices and highlights the need for improved interfacial engineering through optimized adhesion-promoting layers or hybrid protective architectures. 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

Long-term clinical translation of left ventricular assist devices (LVADs) is severely hampered by thromboembolism and device-related infection, both originating from inadequate biocompatibility of the device-blood interface. Current titanium surface modifications fail to simultaneously deliver durable antithrombotic and antibacterial performance, while conventional polydopamine-copper (PDA-Cu) coatings suffer from inherent limitations. Herein, we report a one-step rapid co-polymerization strategy based on mussel-inspired polyphenol chemistry to fabricate a copper-integrated polydopamine/tannic acid nanocoating on titanium (Ti/PDT(Cu)). By incorporating tannic acid rich in catechol/pyrogallol moieties, we achieve synergistic acceleration of dopamine oxidative polymerization with copper ions, dramatically shortening the fabrication time to 8 h (vs. 24 h for traditional PDA coatings). This process simultaneously constructs a robust dual-crosslinked network through covalent/hydrogen bonds and metal-phenolic coordination, exhibiting a uniform nanoscale-roughened structure. Comprehensive physicochemical characterizations confirm homogeneous coating deposition, excellent hydrophilicity, uniform Cu distribution, and superior long-term structural stability (95.68% thickness retention after 7 days of physiological immersion). The optimized coating displays broad-spectrum and durable antibacterial activity, with 92.79% and 89.73% reduction of E. coli and S. aureus at 24 h, respectively, and retains $>$89% antibacterial efficacy after 7 days of continuous elution (n = 3, * p$<$ 0.05). Moreover, the coating enables stable and sustained catalytic nitric oxide generation (43.85 $\pm$ 2.36 μM cumulative release over 14 days) that mimics endothelial function, resulting in 69.4% inhibition of platelet adhesion and an ultralow hemolysis ratio of 0.97% (n = 3). Critically, it maintains excellent cytocompatibility with L929 fibroblasts ($>$90% cell viability after 72 h co-culture). This work addresses key limitations of conventional PDA-based functional coatings, realizes synergistic antithrombotic and antibacterial dual functions showing great potential for blood-contacting cardiovascular device applications, and provides a facile and robust surface engineering platform for long-term implantable cardiovascular devices. Full article

Surface functionalization of metallic implants is widely explored to enhance their performance and functionality. In this study, multifunctional hydrogel coatings based on poly(vinylpyrrolidone) and polyethylene glycol were developed and functionalized with a taxifolin (TAX) inclusion complex and collagen to introduce bioactive features. TAX, a naturally occurring flavonoid with antioxidant and anti-inflammatory properties, was incorporated using β-cyclodextrin to improve its stability and enable controlled release. The coatings were applied to titanium-hydroxyapatite composites and titanium sheet substrates to evaluate their applicability across surfaces with varying morphologies, ranging from porous to relatively smooth. The ceramic phase was modified with magnesium ions to enhance its bioactivity and better mimic the composition of natural bone tissue. FTIR and SEM analyses confirmed hydrogel formation and effective surface coverage. Degradation and incubation studies in simulated physiological environments demonstrated the material’s stability, while UV–Vis analysis indicated TAX release, highlighting the system’s potential as a carrier for flavonoid-based compounds. Indirect cytotoxicity studies using MC3T3-E1 preosteoblasts indicated low cytotoxicity and a favorable biological response of collagen- and taxifolin-modified systems. The developed coatings represent a versatile platform for surface modification of titanium-based biomaterials and demonstrate potential for application across substrates with diverse surface characteristics. Further studies are required to assess their biological potential. Full article

Titanium and its alloys are widely used in dental implantology due to their favorable mechanical properties and well-documented long-term clinical performance. Among them, Ti-6Al-4V is particularly common in load-bearing applications. Nevertheless, a growing body of experimental and clinical evidence suggests that Ti-6Al-4V implants cannot be regarded as biologically inert in all patients. Adverse tissue responses, such as impaired healing, chronic peri-implant inflammation, and unexplained implant failure, have been reported even in the absence of classical risk factors, including infection, mechanical overload, or confirmed metal allergy. This critical review challenges the prevailing assumption that these complications are driven primarily by mechanical or immunoallergic mechanisms. Instead, oxidative stress is proposed as a central and unifying factor underlying adverse tissue reactions to Ti-6Al-4V dental implants. Corrosion, tribocorrosion, and mechanical wear lead to the release of titanium-, aluminum-, and vanadium-containing particles and ions, which promote excessive generation of reactive oxygen species at the implant–tissue interface. The resulting redox imbalance disrupts bone remodeling, impairs osteogenic differentiation, and maintains a pro-inflammatory microenvironment. Importantly, pathology arises not merely from increased reactive oxygen species production, but from the failure of local antioxidant defense systems to counteract this burden. Insufficient enzymatic and transcriptional antioxidant responses result in persistent redox imbalance, sustained innate immune activation, and progressive tissue intolerance. Oxidative stress is therefore conceptualized not as a secondary byproduct of inflammation, but as a primary driver of immune dysregulation through chronic macrophage activation and inflammasome signaling. This redox-driven feedback loop amplifies tissue damage and compromises long-term osseointegration independently of classical adaptive immune sensitization. Recognizing oxidative stress as a key determinant of implant–tissue interactions offers a more coherent framework for understanding implant-related complications and underscores the need for redox-aware biomaterial strategies and individualized patient risk assessment. Full article

Background/Objectives: Childhood is marked by frequent musculoskeletal injuries, with fractures representing a major cause of pediatric trauma admissions. Unstable long-bone fractures often require surgical stabilization, commonly achieved using elastic stable intramedullary nailing (ESIN). Although this method ensures effective fixation and early mobilization, concerns remain regarding potential metal ion release in growing children. This study aimed to assess changes in calcium, magnesium, copper, zinc, titanium, and aluminum concentrations in blood and material from the medullary cavity of forearm fractures following intramedullary fixation. Methods: A prospective study was conducted on 40 patients aged 4–15 years treated with ESIN at the University Children’s Hospital in Lublin. Peripheral blood and material from the medullary cavity were collected before implantation and at implant removal. Elemental concentrations were determined using high-resolution ICP-OES, and statistical analyses included paired comparisons, delta values, and multivariate methods. Results: No significant systemic changes were found for calcium, magnesium, copper, zinc, or aluminum. A modest but significant increase in blood titanium levels was observed after treatment (p = 0.0075), especially in patients with two rods. Multivariate analysis confirmed overall stability of elemental profiles, with titanium contributing most strongly to post-treatment variation. Conclusions: Intramedullary titanium fixation in children does not significantly disrupt systemic mineral homeostasis. The slight increase in circulating titanium reflects implant exposure rather than toxicity, supporting the safety of ESIN, although continued monitoring of metallic elements may be warranted. Full article

Background/Objectives: To prevent potential complications for patients with metal hypersensitivity requiring total knee arthroplasty (TKA), implant coatings have been developed. Thermal nitriding of the titanium surface creates a TiN layer that increases hardness and wear resistance while preventing release of cobalt and chromium ions. The aim of this study was to evaluate the clinical safety and performance of an anatomic implant system comprised of thermally nitrided Ti-6Al-4V. Methods: This is an ongoing prospective, multicenter observational cohort study of primary and revision TKA patients. Patient-reported outcome measures including the Oxford Knee Score (OKS), Knee Society Score (KSS) Expectations subscale, EQ-5D-5L, physical exams, and radiographic assessments to document abnormalities were investigated in 94 patients who provided at least two years of follow-up data. The primary endpoint was improvement in the Oxford Knee Score (OKS), defined as the minimal clinically important difference (MCID, 7.0 points). Results: All outcome measures including patient-reported function (OKS) demonstrated significant improvements (19.4–22.6 points) exceeding the MCID with no between-group differences by bearing types utilized. Health-related quality of life as measured by EQ-5D-5L improved over the cohort and was maintained at 2-years post-operative. In total, three (1.4%) radiographic abnormalities were observed, all of which resolved at two-year follow-up. 12 (5.3%) serious complications were reported, none of which were related to the device. Two revisions have occurred, one due to infection and one due to a fall, in the ultracongruent bearing cohort (survivorship 98.1%, 95%CI 87.4–99.7). Implant survivorship was 100% in all other bearing cohorts. Conclusions: This anatomically designed, thermally nitrided titanium alloy implant demonstrated clinically significant improvements in function, PROMs, and quality of life in patients undergoing TKA regardless of bearing type. Excellent two-year implant survivorship between 98.1% and 100% across cohorts were observed, with no radiographic abnormalities at 2 years. Full article

Total ankle arthroplasty (TAA) has evolved significantly through advances in alloy selection and manufacturing technologies. This narrative review examines the metallurgical foundations of contemporary TAA implants, analyzing primary alloy systems and their mechanical properties. Cobalt-chromium alloys provide superior mechanical strength and durability but present metal ion release concerns, while titanium alloys (Ti6Al4V) optimize biocompatibility with elastic modulus values (101–113 GPa) closer to bone, despite tribological limitations. Novel β-titanium formulations (Ti-35Nb-7Zr-5Ta, Ti10Mo6Zr4Sn3Nb) eliminate toxic aluminum and vanadium components while achieving lower elastic modulus values (50–85 GPa) that better match cortical bone properties. Manufacturing has transitioned from traditional methods (investment casting, forging, CNC machining) toward additive manufacturing technologies. Selective laser melting and electron beam melting enable patient-specific geometries, controlled porosity, and optimized microstructures, though challenges remain with residual stresses, surface finish requirements, and post-processing needs. Emerging biodegradable materials, composite structures, and hybrid implant designs represent promising future directions for addressing current material limitations. This review provides evidence-based insights for alloy selection and manufacturing approaches, emphasizing the critical role of materials engineering in TAA implant performance and clinical outcomes. Full article

Titanium (Ti) and its alloys have attracted more interest, as they are widely employed as biomaterials due to their great biocompatibility, excellent strength ratio, and lightweight. However, corrosion occurs slowly due to an electrochemical reaction once the Ti material has been placed in the human body, contributing to infection and failure of implants in medical applications. Thus, the corrosion phenomenon has caused great concern in the biomedical field. It is desirable to make the surface modification to provide better corrosion resistance. The fabrication techniques of the coatings fabricated onto Ti and/or Ti alloy surfaces have been reported, including sol–gel, annealing, plasma spraying, plasma immersion ion implantation, physical vapor deposition, chemical vapor deposition, anodization, and micro-arc oxidation. This review first describes the corrosion types, including localized corrosion (both pitting and crevice corrosion), galvanic corrosion, selective leaching, stress corrosion cracking (SCC), corrosion fatigue (CF), and fretting corrosion. In the second part, the effects of corrosion on the human body were discussed, and the primary cause for clinical failure and allergies has been identified as the excessive release of poisonous and dangerous metal ions (Co, Ni, and Ti) from corroded implants into bodily fluids. The inclusion and exclusion criteria during the selection of literature are described in the third section. In the last section, we emphasized the current research progress of Ti alloy (particularly Ti6Al4V alloy) coatings in biomaterials for medical applications involving dental, orthopedic, and cardiovascular implants for anticorrosive applications. However, there are also several problems to explore and address in future studies, such as the release of excessive metal ions, etc. This review will draw attention to both researchers and clinicians, which could help to increase the coatings fabricated onto Ti and/or Ti alloy surfaces for anticorrosive applications in biomaterials for medical applications. Full article

The widespread adoption of metal implants in orthopaedics and dentistry has revolutionized medical treatments, but concerns remain regarding their biocompatibility, toxicity, and immunogenicity. This study conducts a comprehensive literature review of traditional biomaterials used in orthopaedic surgery and traumatology, with a particular focus on their historical development and biological interactions. Research articles were gathered from PubMed and Web of Science databases using keyword combinations such as “toxicity, irritation, allergy, biomaterials, corrosion, implants, orthopaedic surgery, biocompatible materials, steel, alloys, material properties, applications, implantology, and surface modification”. An initial pool of 400 articles was screened by independent reviewers based on predefined inclusion and exclusion criteria, resulting in 160 relevant articles covering research from 1950 to 2025. This paper explores the electrochemical processes of metals like iron, titanium, aluminium, cobalt, molybdenum, nickel, and chromium post-implantation, which cause ion release and wear debris formation. These metal ions interact with biological molecules, triggering localized irritation, inflammatory responses, and immune-mediated hypersensitivity. Unlike existing reviews, this paper highlights how metal–protein interactions can form antigenic complexes, contributing to delayed hypersensitivity and complications such as peri-implant osteolysis and implant failure. While titanium is traditionally considered bioinert, emerging evidence suggests that under certain conditions, even inert metals can induce adverse biological effects. Furthermore, this review emphasizes the role of oxidative stress, illustrating how metal ion release and systemic toxicity contribute to long-term health risks. It also uncovers the underappreciated genotoxic and cytotoxic effects of metal ions on cellular metabolism, shedding light on potential long-term repercussions. By integrating a rigorous methodological approach with an in-depth exploration of metal-induced biological responses, this paper offers a more nuanced perspective on the complex interplay between metal implants and human biology, advancing the discourse on implant safety and material innovation. Full article

Titanium (Ti), as a hard tissue implant, is facing a big challenge for rapid and stable osseointegration owing to its intrinsic bio-inertness. Meanwile, surface-related infection is also a serious threat. In this study, large-scale quasi-vertically aligned sodium titanate nanowire (SNW) arrayed coatings incorporated with bioactive Cu²⁺ ions were fabricated through a compound process involving acid etching, hydrothermal treatment (HT), and ion exchange (IE). A novel coating based on sustained ion release and a shape-preserving design is successfully obtained. Cu²⁺ substituted Na⁺ in sodium titanate lattice to generate Cu-doped SNW (CNW), which maintains the micro-structure and phase components of the original SNW, and can be efficiently released from the structure by immersing them in physiological saline (PS) solutions, ensuring superior long-term structural stability. The synergistic effects of the acid etching, bidirectional cogrowth, and solution-strengthening mechanisms endow the coating with higher bonding strengths. In vitro antibacterial tests demonstrated that the CNW coatings exhibited effective good antibacterial properties against both Gram-positive and Gram-negative bacteria based on the continuous slow release of copper ions. This is an exciting attempt to achieve topographic, hydrophilic, and antibacterial activation of metal implants, demonstrating a paradigm for the activation of coatings without dissolution and providing new insights into insoluble ceramic-coated implants with high bonding strengths. Full article

While titanium nitride (TiN) coatings are well known for their biocompatibility and excellent mechanical properties, their wear particle and debris release in orthopedic implants remains a matter of active investigation. This study addresses the efficacy of TiN coatings on CoCrMo and Ti6Al4V alloys to enhance wear resistance and reduce ion release from prosthetic implants. Three different coating variants were utilized: one variant deposited using arc evaporation (Arc) followed by post-treatment, and two variants deposited using high-power impulse magnetron sputtering (HiPIMS) with or without post-treatment. The coatings’ performance was assessed through standard wear testing against ultra-high-molecular-weight polyethylene (UHMWPE) in bovine serum lubricant, and in the presence of abrasive PMMA bone cement particles in the lubricant. The results indicated that Arc and HiPIMS with post-treatment significantly reduced wear and eliminated detectable metal ion release, suggesting that these coatings could extend implant longevity and minimize adverse biological responses. Further long-term simulator and in vivo studies are recommended to validate these promising findings. Full article

The improved peri-implant bone response demonstrated when utilizing the platform-switching concept may result from the reduced levels of metal ions released from implant–abutment surfaces to the surrounding tissues. These corrosion products may play a major role in crestal bone remodeling around dental implants. This study evaluated the effect of different implant–abutment couplings (platform-matched vs. platform-switched) on osteoblasts’ function. Titanium alloy and cobalt–chrome alloy abutments were coupled with titanium cylinders, forming either platform-switched or platform-matched groups, and were incubated in human osteoblast cultures utilizing a novel direct-exposure technique. Viability was evaluated over 21 days using Alamar Blue assay. Apoptosis was measured after 24 h using flow cytometry. The expression of genes related to bone resorption was analysed over 21 days using a real-time quantitative polymerase chain reaction assay. Cell viability was reduced from day 4 to day 21 (p < 0.05), with higher rates of early apoptosis (p < 0.05) compared to the controls. Apoptosis was higher in the platform-matched groups (p < 0.05). The tested genes’ expression was up-regulated after 1 and 3 days of exposure to implant–abutment couplings (p < 0.05). The upregulation was more pronounced in platform-matched groups (p < 0.05). Exposure of osteoblasts to implant–abutment couplings induced adverse biological responses, which were more pronounced with platform-matched couplings. These reactions might be related to the increased amounts of metal ions released from the platform-matched couplings, highlighting the possible role of corrosion products in the mediation of crestal bone loss around dental implants. Full article

TC4 alloy is widely used in dental implantation due to its excellent biocompatibility and low density. However, it is necessary to further improve the corrosion resistance and surface hardness of the titanium alloy to prevent surface damage that could result in the release of metal ions into the oral cavity, potentially affecting oral health. In this study, Ti-N-O layers were fabricated on the surface of TC4 alloy using a two-step hollow cathode plasma source oxynitriding technique. This resulted in the formation of TiN, Ti₂N, TiO₂, and nitrogen-stabilized α(N)-Ti phases on the TC4 alloy, forming a Ti-N-O modified layer. The microhardness of the samples treated with plasma oxynitriding (PNO) was found to be 300–400% higher than that of untreated (UN) samples. The experimental conditions were set at 520 °C, and the corrosion current density of the PNO sample was measured to be 7.65 × 10⁻⁸ A/cm², which is two orders of magnitude lower than that of the UN sample. This indicates that the PNO-treated TC4 alloy exhibited significantly improved corrosion resistance in the artificial saliva solutions. Full article

Dental implants are thought to be implanted for life, but throughout their lifespan, they function in aggressive oral environment, resulting in corrosion of the material itself as well as possible inflammation of adjacent tissues. Therefore, materials and oral products for people with metallic intraoral appliances must be chosen carefully. The purpose of this study was to investigate the corrosion behavior of common titanium and cobalt–chromium alloys in interaction with various dry mouth products using electrochemical impedance spectroscopy (EIS). The study showed that different dry mouth products lead to different open circuit potentials, corrosion voltages, and currents. The corrosion potentials of Ti64 and CoCr ranged from −0.3 to 0 V and −0.67 to 0.7 V, respectively. In contrast to titanium, pitting corrosion was observed for the cobalt–chromium alloy, leading to the release of Co and Cr ions. Based on the results, it can be argued that the commercially available dry mouth remedies are more favorable for dental alloys in terms of corrosion compared to Fusayama Meyer’s artificial saliva. Thus, to prevent undesirable interactions, the individual characteristics of not only the composition of each patient’s tooth and jaw structure, but also the materials already used in their oral cavity and oral hygiene products, must be taken into account. Full article