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Abstract: To achieve excellent biocompatibility of metal-based implants, hydroxyapatite thin film coatings on nanotube-formed Ti–35Nb–10Zr alloys after femtosecond laser texturing have been investigated. Three groups of samples were prepared: (1) microtextured surfaces using femtosecond (FS) laser, (2) nanotube surfaces formed by anodization, and (3) hydroxyapatite coatings vapor-deposited by a physical electron beam method on the Ti–35Nb–10Zr ternary alloy. The surface morphology of the Ti–35Nb–10Zr alloys was examined by x-ray diffractometry, field-emission scanning electron microscopy, and energy-dispersive x-ray spectroscopy. To investigate ion release, potentiodynamic polarization testing was carried out in 0.9%NaCl solution, and wettability tests and MG 63 osteoblast-like cell culture studies were performed on the surfaces of the three groups to evaluate contact angle and cell growth morphology, respectively. The Ti–35Nb–10Zr alloys exhibited the equiaxed β phase structure. The FS laser-treated Ti–35Nb–10Zr alloys showed circular traces with diameters of 28±1.5μm and hole separations of 50μm, and the nanotubes formed on the surfaces had diameters of 180±15nm and compositions consistent with TiO2, Nb2O5, and ZrO2. The nanotube structure showed anatase, rutile and β-titanium diffraction peaks, whereas the HA-coated surface on the nanotubes showed hydroxyapatite, anatase and rutile peaks. The HA coatings displayed the desired role of decreasing the metal ion release with a lower current density value, and the nanotubes and FS laser-treated surface showed wider passive regions compared to other surfaces. The HA-coated surface on the nanotubes after FS laser texturing showed the lowest contact angle compared with the other surfaces. From FE-SEM observations, cell attachment and spreading of MG 63cells showed significantly higher tendency for surfaces covered by HA coating and nanotubes. [Copyright &y& Elsevier]

ABSTRACT The phenomena of hydroxyapatite (HA) precipitation in micropore-structured Ti alloy have been studied using transmission electron microscopy and field-emission SEM (FE-SEM). HA layer was grown on anodized Ti surface by electrochemical deposition process in modified simulated body fluid at 85 °C. The deposition process involved two steps: (i) porous TiO2 on Ti alloy was formed at high potential, and (ii) cyclic voltammetric method was carried out in modified simulated body fluid for HA electrodeposition on anodized Ti alloys. Homogenized Ti-30Nb alloy showed the equiaxed structure with β phase, whereas the Ti-30Ta alloy showed the martensite structure with α″ phase. In case of anodized Ti binary alloys at applied 270 V, the anodized surface showed the uniform pore formation and Ca/P ratio was the range of 1.61 and 1.72. HA was formed with plate and fiberlike shape on anodized Ti alloys. HA was precipitated densely in the pore and connected with each other in the TiO2 layer. The selected-area diffraction patterns of the HA were composed of rings and intense spots with some crystallized precipitates. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: The nanotubular surface of Ti-binary and Ti-ternary alloys for biomaterials has been investigated using various methods of surface characterization. Binary Ti-xNb (x=10, 20, 30, and 40wt.%) and ternary Ti-30Ta-xNb (x=3, 7 and 15wt.%) alloys were prepared by using the high-purity sponges; Ti, Ta and Zr spheres. The nanotube on the alloy surface was formed in 1.0M H3PO4 with small additions of NaF (0.5 and 0.8wt.%), using a potentiostat. For cell proliferation, an MC3T3-E1 mouse osteoblast was used. The surface characteristics were investigated using field-emission scanning electron microscope, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy. Binary Ti-xZr alloys had a lamellar and a needle-like structure, whereas, ternary Ti-30Ta-xZr alloys had equiaxed grains with a lamellar martensitic α′ structure. The thickness of the needle-like laths of the α-phase increased as the Zr content increased. The nanotubes formed on the α phase and β phase showed a different size and shape appearance with Zr content. As the Zr content increased from 3 to 40wt.%, the diameter of the nanotubes in Ti-xZr and Ti-30Ta-xZr alloy decreased from 200nm to 50nm. The nanotubular Ti-30Ta-15Zr alloy surface with a diameter of 50nm provided a good osseointegration; cell proliferation, migration and differentiation. [Copyright &y& Elsevier]

[Display omitted] • Research on mechanical synthesized Wollastonite/Forsterite coatings(MSC) on porous Ti-alloy. • Apatite formation was accelerated on the Wollastonite/Forsterite coating layers. • Wollastonite dissolution controlled by Forsterite addition. • Wollastonite/Forsterite coating layers improved the corrosion resistance. This study investigated an innovative approach for dental implant coatings by developing mechano-synthesized wollastonite-forsterite composite coatings (MC) on plasma electrolytic oxidized (PEO) Ti-6Al-4V alloy. The process involved PEO treatment using a pulsed DC power supply in an electrolyte solution of mono-calcium acetate and calcium glycerophosphate, followed by MC with mixed wollastonite (CaSiO 3) and forsterite (Mg 2 SiO 4) powders. After MC treatment, FESEM, EDS analysis, cross-section, XPS, Raman analysis, corrosion test, and an in vitro test for biocompatibility were performed. Comprehensive surface characterization revealed that wollastonite particles transformed into smaller needle-like shapes, while forsterite particles became slightly less uniform but retained their spherical shape. Higher wollastonite content resulted in greater pore filling with fine particles, whereas increased forsterite content led to fewer fine particles on the surface. Cross-sectional analysis showed Si concentration inside the pores. Notably, wollastonite-rich samples exhibited superior corrosion resistance and rapid initial apatite formation in simulated body fluid (SBF) studies. In contrast, forsterite-containing samples demonstrated more controlled and sustained bioactivity, forming magnesium-substituted hydroxyapatite over time. The novelty of this work lies in combining the bioactive properties of wollastonite and forsterite with enhanced PEO surface characteristics, resulting in coatings with tailored corrosion resistance and bioactivity profiles suitable for dental implant applications. [ABSTRACT FROM AUTHOR]

The deposition of ultra-fine Pd/Ag/HAp nanoparticles onto TiO 2 nanotubes has been performed by an electrochemical method using a mixed electrolyte solution. Electrochemical deposition was carried out under constant voltage, and Pd/Ag/HAp nanoparticles were carefully added in the mixed electrolyte of 1.7 M (NH 4 )H 2 PO 4 + 0.4 M NH 4 F, which was slowly rotated by a magnetic stirrer on a hot plate in order to increase the diffusion rate of electrolyte ions. The electrochemical deposition behavior, chemical bonding state, and surface characteristics of the Pd/Ag/HAp nanoparticles have been investigated by FE-SEM, EDS, and XPS. The Pd/Ag/HAp nanoparticles were uniformly electrodeposited onto the whole top surface and around the tube walls, including the inner side and outer side, of the ultra-fine TiO 2 nanotubes. The ordered tubular structure was well-maintained without destruction during the electrochemical deposition process. With excessive activation up to a deposition time of 7200 s, continuous granular Pd/Ag/HAp nanoparticles gradually formed with a rough surface around the top of the TiO 2 nanotube layer. From the XPS and EDS analyses, Ti, Ca, P, Pd, and Ag were detected in the nanoparticles on the electrochemically deposited surfaces. The surface morphology after soaking in SBF exhibited hydroxyapatite-like precipitates, which consisted of the four elements Ti, O, Ca, and P, and having a Ca/P atomic ratio of 1.67. [ABSTRACT FROM AUTHOR]

Abstract: A thin hydroxyapatite (HA) film was deposited on anodized titanium for the biocompatibility by RF sputtering method. The anodized titanium has improved its bioactivity further by the HA deposition on the anodized titanium surface. TiO2 layer with 0.2~0.5μm diameter pore size was formed on the Ti surface by anodization. HA film deposited surface showed that the pore size and number decreased compared with non-HA deposited surface. The corrosion resistance of HA deposited/anodized Ti was higher than that of the non-treatment Ti alloy in Hank''s solution, indicating better protective effect. From the results of cell culture using MTT assays, the best cell proliferation showed in HA deposited surface after anodization of Ti surfaces compared with another surface treatment. [Copyright &y& Elsevier]

Hydroxyapatite deposition on micropore-formed Ti-Ta-Nb alloys by plasma electrolytic oxidation for dental applications was investigated. Ti-35Ta-xNb alloys (x = 0 and 10 wt.%) were prepared with an arc-melting furnace. Micropores were formed on the Ti-35Ta-xNb alloys in 0.15 M calcium acetate monohydrate + 0.02 M calcium glycerophosphate at 280 V for 3 min. Hydroxyapatite deposition were carried out on the alloy surfaces using cyclic voltammetry in 2.5 mM Ca(NO 3 ) 2 ∙ 4H 2 O + 1.5 mM NH 4 H 2 PO 4 solution with various deposition cycles. Morphology and structure of the alloy surfaces and hydroxyapatite were investigated by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. The microstructure of Ti-35Ta-xNb alloys showed the α″ and β phases, and the XRD peak for the β phase increased with Nb content. For the non-NaOH treated surface, the morphology of HA deposited on Ti-35Ta-xNb alloys showed a plate-like shape, whereas the HA particle shape on the micropore-structured Ti-35Ta-xNb alloys was flower-like. The pore size and thickness of the surface barrier layer increased as the voltage increased. The fraction of rutile also increased as the applied potential increased. The anatase and rutile phases of TiO 2 can be controlled by applied voltage for enhanced biocompatibility. [ABSTRACT FROM AUTHOR]

Hydroxyapatite deposition on micropore-formed Ti-Ta-Nb alloys by plasma electrolytic oxidation for dental applications was investigated. Ti-35Ta-xNb alloys (x = 0 and 10 wt.%) were prepared with an arc-melting furnace. Micropores were formed on the Ti-35Ta-xNb alloys in 0.15 M calcium acetate monohydrate + 0.02 M calcium glycerophosphate at 280 V for 3 min. Hydroxyapatite deposition were carried out on the alloy surfaces using cyclic voltammetry in 2.5 mM Ca(NO 3 ) 2 ∙ 4H 2 O + 1.5 mM NH 4 H 2 PO 4 solution with various deposition cycles. Morphology and structure of the alloy surfaces and hydroxyapatite were investigated by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. The microstructure of Ti-35Ta-xNb alloys showed the α″ and β phases, and the XRD peak for the β phase increased with Nb content. For the non-NaOH treated surface, the morphology of HA deposited on Ti-35Ta-xNb alloys showed a plate-like shape, whereas the HA particle shape on the micropore-structured Ti-35Ta-xNb alloys was flower-like. The pore size and thickness of the surface barrier layer increased as the voltage increased. The fraction of rutile also increased as the applied potential increased. The anatase and rutile phases of TiO 2 can be controlled by applied voltage for enhanced biocompatibility. [ABSTRACT FROM AUTHOR]

The biocompatibility structure of an implant surface is of great importance to the formation of new bone tissue around the dental implant and also has a significant chemical reaction in the osseointegration process. Thus, ultra-fine Pd-Ag-HAp nanoparticles have been electrodeposited on protruded TiO 2 barrier layer in mixed electrolyte solutions. Unusual protrusions patterns, which are assigned to Pd-Ag-HAp nanoparticles, can be clearly differentiated from a TiO 2 nanotube oxide layer formed by an anodizing process. In the chemical bonding state, the surface characteristics of Pd/Ag/HAp compounds have been investigated by FE-SEM, EDS mapping analysis, and XPS analysis. The mapping dots of the elements including Ti, Ca, Pd, Ag, and P showed a homogeneous distribution throughout the entire surface when deposited onto the protruded TiO 2 barrier layer. The XPS spectra of Ti-2p, O-1S, Pd-3d, and Ag-3d have been investigated, with the major XPS peak indicating Pd-3d. The Ag-3d level was clearly observed with further scanning of the Ca-2p region. Based on the results of the chemical states, the structural properties of the protrusion patterns were also examined after being deposited onto the barrier oxide film, resulting in the representative protrusion patterns being mainly composed of Pd-Ag-HAp compounds. The results of the soaking evaluation showed that the protrusion patterns and the protruded TiO 2 barrier layer were all effective in regards to biocompatibility. [ABSTRACT FROM AUTHOR]

Abstract: The biocompatibility of anodized titanium (Ti) was improved by an electrochemically deposited calcium phosphate (CaP) layer. The CaP layer was grown on the anodized Ti surface in modified simulated body fluid (M-SBF) at 85°C. The phases and morphologies for the CaP layers were influenced by the electrolyte concentration. Nano flake-like precipitates that formed under low M-SBF concentrations were identified as hydroxyapatite (HAp) crystals orientated in the c-axis direction. In high M-SBF concentrations, the CaP layer formed micro plate-like precipitates on anodized Ti, and micropores were covered with HAp. Proliferation of murine preosteoblast cell (MC3T3-E1) on the HAp/anodized Ti surfaces was significantly higher than for untreated Ti and anodized Ti surfaces. [Copyright &y& Elsevier]