Search Results (143)

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

Silver nanoparticles (AgNPs) have gained significant interest across various areas arising from their multifunctional mechanisms. Biomedical applications are one of the areas where the therapeutic and diagnostic potential of AgNPs are highlighted. Considering the expansion of biomedical use of AgNPs, nervous system-based applications, including neuroimaging, neural implant coatings and development of neural tissue-targeted drug delivery systems are some of the potential applications of AgNPs in the current research. However, growing interest in these nervous system related applications and the limited regenerative capacity of neural tissues make it essential to carefully evaluate the potential neurotoxic effects of AgNPs. AgNP-induced responses in neural tissues may differ according to key physicochemical and exposure-related parameters, specifically particle size, shape, surface chemistry, coating properties, protein corona formation, exposure route, dose, and duration. Among the possible mechanisms that may contribute to these responses are blood–brain barrier (BBB) disruption, mitochondrial dysfunction and oxidative stress, neuroinflammation and glial activation, and cell death processes such as apoptosis, autophagy, and ferroptosis. In this review, in the context of the potential neurotoxic effects of AgNPs on the nervous system, the main parameters that determine AgNP neurotoxicity and the possible mechanisms involved are examined in detail, where recent scientific developments in this field are evaluated based on current in vitro and in vivo studies. Full article

Chitosan–hydroxyapatite (CS–HA) composite coatings offer a multifunctional surface modification to improve titanium implant performance, combining hydroxyapatite’s osteoconductivity with chitosan’s biocompatibility and antimicrobial properties. This review examines recent in vitro and in vivo studies, noting consistent enhancements in osteoblast adhesion, alkaline phosphatase activity, apatite formation, and bone–implant contact. Incorporation of silver, strontium, or graphene oxide can further boost antibacterial and osteogenic effects. However, variability in coating preparation, substrate treatment, and testing protocols limits reproducibility and clinical extrapolation. Standardised methodologies and extended in vivo validation are essential to advance CS–HA coatings toward reliable dental and orthopaedic applications. Full article

Objectives: In dental implantology, the priorities in scientific research are to identify solutions that guarantee a beneficial biomaterial–tissue interaction, both in terms of implant biointegration and protection against infections. The experimental approach consisted of chemical deposition of silver (Ag), silver and hydroxyapatite (HAP) on a TiZr metallic support. The aim of the research is to study the influence of hydroxyapatite on the possible adverse effects produced by silver in antibacterial coatings. Methods: The characterization of the coating was performed by scanning electron microscopy (SEM) and EDS spectroscopy, XRD diffraction and FT-IR infrared analysis. In vitro cell viability and adhesion testing was performed by quantitative (MTT) and qualitative fluorescence-based assays on samples (without deposition and with chemical deposition), in the presence of human fetal osteoblasts (hFOB cell line) after 8 days of incubation. Results: The findings of the study indicate an increase in cell viability by combining silver with hydroxyapatite. Preliminary data indicated a cell viability of 20% when the metal support is coated exclusively with silver and 60% in the presence of hydroxyapatite in the silver coating. Conclusions: The experimental study offers insights into the potential cytotoxic effects of silver in antibacterial coatings. Co-deposition with hydroxyapatite improved osteoblast viability compared to surfaces coated with silver alone, indicating that it may have a beneficial effect in Ag-based surface functionalization. The underlying mechanism (e.g., modulation of silver species/ion release) was not directly quantified in this work and should be addressed in future studies. Full article

Metal nanoparticles (NP) are increasingly used in biomedical applications. Among them, silver NPs (AgNPs) are used as active components in antibacterial coatings for wound dressings, medical devices, implants, cosmetics, textiles, and food packaging. On the other hand, AgNPs can be toxic to humans, depending on the dose and route of exposure, as agents delivering silver to cells. The cysteine residues are the primary molecular targets in such exposures, due to the high affinity of Ag⁺ ions to thiol groups. The Endothelial monocyte-activating polypeptide II (EMAP II), a cleaved C-terminal peptide of the intracellular aminoacyl-tRNA synthetase multifunctional protein AIMP1, contains five cysteines exposed at its surface. This prompted the question of whether they can be targeted by Ag⁺ ions present at the AgNPs surface or released from AgNPs in the course of oxidative metabolism of the cell. We explored the interactions between recombinant EMAP II, tRNA, and AgNPs using UV-Vis and fluorescence spectroscopy, providing insight into the effects of AgNPs dissolution kinetics on interaction EMAP II with tRNA. In addition, the EMAP II fragments binding to intact AgNPs were established by heteronuclear ¹H-¹⁵N HSQC spectra utilizing a paramagnetic probe. Structural analysis of the EMAP II reveal that the 3D structure of protein was destabilized (partially denatured) by the binding of Ag⁺ ions released from AgNPs at the most exposed cysteines. Surprisingly, this effect enhanced tRNA affinity to EMAP II, lowering its $K_d$. The course of the EMAP II/tRNA/AgNP reaction was also modulated by other factors, such as the presence of Mg²⁺ ions and TCEP, a thiol-group protector used to mimic the reducing conditions of the cell. Full article

Despite metals currently being widely used in orthopedic surgery, their mechanical properties significantly differ from the surrounding tissues and organs, causing low biocompatibility. Biodegradable, non-toxic, and non-immunogenic materials seem to be more convenient for clinical implementation. Our research was aimed at the construction of a polylactide screw covered with collagen, nanohydroxyapatite, and polylactide, with a variant including silver nanowires for antibacterial properties, as well as the analysis of their physico-chemical and biological properties. Adherent human osteosarcoma cells (2T line) were shown to grow on the porous surface layers. A cytotoxicity assay using WST1 revealed the non-toxic nature of the coatings and showed an increase in cell adhesion and proliferation. Safety and efficacy were also evaluated in vivo with the coated screws implanted into the metatarsal bones of minipigs. Histological analysis at 29 and 58 days post-screw-implantation revealed that the coated samples accelerated bone tissue regeneration compared to uncoated controls. This was evidenced by a higher bone-to-granulation tissue ratio, reduced inflammatory cell counts, and increased osteoblast/osteoclast activity at the early stage during the initial days after implantation. The results confirm that the developed bioactive coatings enhance biocompatibility and osteointegration. Full article

The surface modification of medical implant materials stands as a favorable strategy to enhance their biological properties including their antibacterial effect and biocompatibility. Recently, both in vitro and in vivo studies have shown that film heterostructures based on a combination of noble metal sublayers and an active component, such as silver and gold nanoparticles, offer unique advantages. The present work develops this promising direction and focuses on a series of combinations of noble metal coatings functionalized with bimetallic nanoclusters obtained by vapor-phase deposition methods onto the surfaces of Ti-based implants. This investigation investigates the influence of sequential deposition (AgAu or AuAg) and noble metal component (Ir or Au) on the coating morphology and the active component chemical form and release. Thus, scanning electron microscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma atomic emission spectroscopy have been applied to characterize the samples before and after in vivo biological studies (rat models, 1 and 3 months). Histological and blood analyses confirmed the high biocompatibility of all the heterostructures. The samples also showed a pronounced in vitro biocidal effect against Gram-positive (S. epidermalis) and Gram-negative (P. aeruginosa) bacteria that correlates with a dynamic of silver release. The AuAg/M heterostructures demonstrated superior biological characteristics compared to their AgAu/M counterparts, suggesting enhanced both long-term integration and antibacterial action. Full article

This work describes the preparation and characterization of chitosan-based biopolymer coatings containing silver, zinc, and hydroxyapatite nanoparticles deposited on the Ti13Zr13Nb alloy by the EPD method. It was intended to evaluate the influence of surface pretreatments and deposition parameters on the structural, electrochemical, and biological properties of coatings. The morphology and composition were characterized by means of SEM/EDS, AFM, XRD, and FTIR analysis. The obtained results indicated uniform continuous layers with homogeneously distributed nanoparticles and the presence of characteristic functional groups originating from chitosan and hydroxyapatite. Corrosion investigations performed in SBF solution revealed a significant enhancement in corrosion resistance for chitosan/nanoAg/nanoZn/nanoHAp coatings, reflected in a drastic decrease in corrosion current density compared with uncoated Ti13Zr13Nb alloy. The contact angle measurements confirmed their hydrophilic nature, which favors better biointegration ability. Biological tests (MTT and LDH) performed on human osteoblasts (hFOB 1.19) confirmed high biocompatibility (>85% cell viability) in the case of all coatings with the addition of hydroxyapatite, whereas in the case of coatings without HAp, cytotoxicity was observed, probably due to the uncontrolled release of metallic nanoparticles. These findings suggest that the presence of hydroxyapatite in chitosan-based coatings efficiently enhances corrosion protection and cytocompatibility, showing very good prospects for biomedical applications such as the surface modification of titanium implants. Full article

Objective: The Ti6Al4V titanium alloy is widely used for dental implants because of its excellent mechanical properties, corrosion resistance, and biocompatibility. However, its bioinert surface limits both osseointegration and resistance to bacterial colonization. Methods: To address these challenges, this study develops a composite coating based on calcium phosphate (CaP) and silver (Ag), reinforced with zirconium oxide (ZrO₂). The coating was deposited on Ti6Al4V using an immersion technique to improve the surface properties of the alloy. Electrochemical analyses (OCP, EIS, and potentiodynamic polarization) were performed in simulated physiological conditions to evaluate the corrosion behavior, while SEM/EDS was used to characterize the surface morphology and composition. Results: The Ag- and Zr-containing CaP coatings significantly improved the corrosion resistance of Ti6Al4V compared with uncoated and CaP-coated samples. Conclusions: This approach provides a promising strategy to enhance the electrochemical stability and long-term durability of titanium dental implants, thereby contributing to their reliable performance in the oral environment. Full article

Microbial colonization is a major factor contributing to peri-implantitis, and creating durable glassy surfaces with antimicrobial agents such as silver and copper may reduce microbial accumulation on dental abutments. This study aimed to develop antimicrobial thin-film glassy surfaces on Ti6Al4V alloy and to evaluate their surface and mechanical properties, antimicrobial effectiveness, and biocompatibility before and after thermal aging. A sol–gel-derived glassy matrix (G) was synthesized, and two antimicrobial coatings were prepared by incorporating ionic Ag (GAg) or a combination of Ag/Cu (GAgCu). Ti6Al4V specimens; these were either left uncoated or dip-coated with G, GAg, or GAgCu and cured at 450 °C. Half of the specimens underwent thermal aging between 5 °C and 55 °C for 3000 cycles. Surface roughness, contact angle, hardness, adhesion strength, scratch resistance, cytotoxicity (Agar diffusion and MTT assay on L929 fibroblasts), and microbial adhesion were evaluated using Streptococcus sanguinis, Porphyromonas gingivalis, and Candida albicans as representative oral microorganisms. Both coatings exhibited low surface roughness, hydrophilic surfaces, improved hardness, and significantly reduced microbial adhesion for all tested species. GAg showed superior mechanical properties, whereas GAgCu demonstrated a relatively stronger antimicrobial effect. Cytotoxicity tests indicated that all coatings were biocompatible at levels suitable for oral use. Overall, these coatings demonstrated strong adhesion, durability, and antimicrobial activity, suggesting their suitability for dental abutments made of Ti6Al4V. Full article

Implant-associated infections (IAIs) remain a major cause of orthopedic implant failure, motivating the development of surface coatings that deliver durable antibacterial activity without compromising host compatibility. Here, we deposit silver (Ag) thin films onto commercially pure titanium (Ti) using high power impulse magnetron sputtering (HiPIMS) and assess their antibacterial performance and osteoblast cytocompatibility. Film formation, morphology and crystallinity were characterized by electron microscopy and X-ray diffractometry, while interfacial integrity was probed using ASTM D3359 cross-cut and VDI 3198 Rockwell-C indentation. Antibacterial activity against Escherichia coli and Staphylococcus aureus was quantified by culture-based enumeration, and Ag⁺ release was measured by ICP-MS. HiPIMS enabled rapid formation of dense, continuous and crystalline Ag films with excellent adhesion. Even ultrathin coatings (~7 nm) produced strong antibacterial effects (activity value > 2.0) while releasing controllable trace Ag⁺ (ultimately 0.43 ppb/day), and osteoblast assays indicated no cytotoxicity under the tested conditions. The results show that HiPIMS-Ag achieves a favorable balance between antimicrobial efficacy and biocompatibility at low thickness, supporting its use as a robust antibacterial surface for Ti implants and providing a foundation for translation to device level and in vivo studies. Full article

Background: Megaprosthetic replacement is widely used following tumour resection but remains challenged by periprosthetic joint infection (PJI) and variable functional outcomes. This narrative review aims to summarise current evidence on infection rates, prevention strategies, and functional outcomes following proximal humerus megaprosthetic reconstruction. We hypothesise that antibacterial coatings and improved soft-tissue techniques reduce infection rates and enhance functional recovery. Methods: A comprehensive narrative review of PubMed, Web of Science, and the Cochrane Library was performed using the terms proximal humerus, shoulder, bone tumor, sarcoma, neoplasm, infection, megaprosthesis, and endoprosthetic replacement. Reference lists were screened manually. Case reports and series with fewer than five patients were excluded. Twenty-seven clinical studies (more than 1100 patients; mainly osteosarcoma, chondrosarcoma, and metastatic lesions) were included and qualitatively analyzed. Results: The reported infection rates ranged from 4% to 20%, with higher risk in patients receiving adjuvant therapy. Silver-coated implants reduced PJI compared with uncoated designs (e.g., 11.2% → 9.2% in primary implants; 29.2% → 13.7% in revisions) without systemic toxicity. Alternative antibacterial coatings (e.g., silver- or copper-enriched hydroxyapatite) showed promising early results but remain supported by limited clinical data. Soft-tissue stabilization with Trevira tube or synthetic mesh improved joint stability and did not increase infection risk. Functional outcomes, usually assessed by MSTS or TESS, were moderate to good (≈60–80%) overall, with better scores when the deltoid and axillary nerve were preserved or when reverse total shoulder arthroplasty was possible. Conclusions: Proximal humerus megaprosthetic reconstruction benefits from meticulous soft-tissue handling, selective use of antibacterial technologies, and multidisciplinary management. The current literature is mainly retrospective, heterogeneous, and non-comparative. Prospective multicenter studies are needed to clarify the long-term effectiveness of silver or alternative coatings, soft-tissue reconstruction techniques, and emerging custom-made 3D-printed prostheses. Full article

Background/Objectives: A comparative study of silver (Ag), titanium nitride (TiN), zirconium nitride (ZrN), and copper (Cu) coatings on titanium (Ti) disks, considering the specifications of a microporous skin- and bone-integrated titanium pylon (SBIP), was performed to assess their biocompatibility, osseointegration, and mechanical properties. Methods: To assess cytotoxicity and biocompatibility, Ti disks with various metal coatings were co-cultured with FetMSCs and MG-63 cells for 1, 3, 7, and 14 days and subsequently evaluated using a cell viability assay, as supported by SEM and confocal microscopy studies. The antimicrobial activity of the selected four materials coating the implants was tested against S. aureus by mounting Ti disks onto the surface of LB agar dishes spread with a bacterial suspension and measuring the diameter of the growth inhibition zones. Quantitative Real-Time Polymerase Chain Reaction (RT-PCR) analysis of the relative gene expression of biomarkers that are associated with extracellular matrix components (fibronectin, vitronectin, type I collagen) and cell adhesion (α2, α5, αV integrins), as well as of osteogenic markers (osteopontin, osteonectin, TGF-β1, SMAD), was performed during the 14-day follow-up period. Additionally, the activity of matrix metalloproteinases (MMP-1, -2, -8, -9) was assessed. Results: All samples with metal coatings, except the copper coating, demonstrated a good cytotoxicity profile, as evidenced by the presence of a cellular monolayer on the sample surface on the 14th day of the follow-up period (as shown by SEM and inverted confocal microscopy). All metal coatings enhanced MMP activity, as well as cellular adhesion and osteogenic marker expression; however, TiN showed the highest values of these parameters. Significant inhibition of bacterial growth was observed only in the Ag-coated Ti disks, and it persisted for over 35 days. Conclusions: The silver-based coating, due to its high antibacterial activity, low cytotoxicity, and biointegrative capacity, can be recommended as the coating of choice for microporous titanium implants for further preclinical studies. Full article

NiTi alloys are widely used in biomedical applications due to their shape memory and superelastic properties. However, their surface reactivity requires protective, biofunctional coatings. To enhance NiTi performance, its surface was modified with an Ag-SiO₂-TiO₂ nanocoating containing small amounts of silica and silver. The coating’s primary phase was rutile with structural defects and a silver solid solution. It showed good adhesion, high scratch resistance, and improved corrosion behavior in Ringer’s solution, as demonstrated by EIS and cyclic polarization. EIS revealed high low-frequency impedance and two time constants, suggesting both barrier protection and slower electrochemical processes. Despite low breakdown and repassivation potentials, the coating effectively limited uniform corrosion. SEM/EDS confirmed localized degradation and partial substrate exposure, while elemental mapping showed well-dispersed silica and silver in a TiO₂-rich matrix. The proposed pitting mechanism involves chloride-induced depassivation and galvanic effects. Surface potential mapping indicated electrostatic heterogeneity, mitigated by silica. The coating offers a balanced combination of corrosion protection and biofunctionality, supporting its potential for implant use. Full article

Background/Objective: Clinical statistics show that bacterial infection is a major driver of implant failure. To enhance antibacterial performance, some metallic elements, such as silver (Ag), zinc (Zn), and copper (Cu), are commonly used to modify the titanium surface. Despite the promising antibacterial performance of Ag, concerns persist regarding dose-dependent cytotoxicity, systemic accumulation, and potential effects on local bone metabolism. This review aimed to investigate the effects of incorporating or coating titanium (Ti) implant surfaces with Ag on bone formation around implants. Methods: A search was undertaken using three main databases (PubMed, Web of Science, and Scopus). The search was limited to studies published within the last 20 years that involved animal experiments using endosseous implants coated with or incorporating Ag. Meta-analyses were performed for bone-to-implant contact (BIC), bone formation (BA), and bone volume (BV/TV) around the implant in control and test groups. The compared groups were subjected to similar implant surface treatments aside from the presence of silver in the test group. Results: Sixteen studies met the inclusion criteria in this study and were included. The analysis of BIC values revealed a statistically significant overall effect in favor of silver-coated implants (Z = 2.01, p = 0.04), along with 95% confidence intervals (CIs). The BA analysis found no significant difference between silver-coated and control implants (Z = 1.09, p = 0.28). The BV/TV analysis also showed no statistically significant overall difference (Z = 0.35, p = 0.73). Conclusions: In animal models, silver-coated Ti implants improve bone–implant contact without altering peri-implant bone volume metrics. Full article