Surface Properties Of Titanium Research Articles

Microstructure and properties of TiCuZnSn alloy layer on titanium fabricated by friction stir processing

Surface modification is an effective method to improve the surface properties of biomedical titanium. In this study, TiCuZnSn alloy layer was successfully prepared on pure titanium by friction stir processing (FSP). The grain size of the titanium surface-modified layer was significantly refined, accompanied by the formation of Sn3Ti5 and CuZn phases. After annealing heat treatment, the wear and corrosion resistance of the TiCuZnSn alloy layer was significantly improved compared with that of the titanium substrate.

Micro-arc driven porous ZrO2 coating for tailoring surface properties of titanium for dental implants application

Titanium (Ti) is an ideal material for dental implants due to its excellent properties. However, corrosion and mechanical wear lead to Ti ions and particles release, triggering inflammatory responses and bone resorption. To overcome these challenges, surface modification techniques are used, including micro-arc oxidation (MAO). MAO creates adherent, porous coatings on Ti implants with diverse chemical compositions. In this context, zirconia element stands out in its wear and corrosion properties associated with low friction and chemical stability. Therefore, we investigated the impact of adding zirconium oxide (ZrO2) to Ti surfaces through MAO, aiming for improved electrochemical and mechanical properties. Additionally, the antimicrobial and modulatory potentials, cytocompatibility, and proteomic profile of surfaces were investigated. Ti discs were divided into four groups: machined – control (cpTi), treated by MAO with 0.04 M KOH – control (KOH), and two experimental groups incorporating ZrO2 at concentrations of 0.04 M and 0.08 M, composing the KOH@Zr4 and KOH@Zr8 groups. KOH@Zr8 showed higher surface porosity and roughness, even distribution of zirconia, formation of crystalline phases like ZrTiO4, and hydrophilicity. ZrO2 groups showed better mechanical performance including higher hardness values, lower wear area and mass loss, and higher friction coefficient under tribological conditions. The formation of a more compact oxide layer was observed, which favors the electrochemical stability of ZrO2 surfaces. Besides not inducing greater biofilm formation, ZrO2 surfaces reduced the load of pathogenic bacteria evidenced by the DNA-DNA checkerboard analysis. ZrO2 surfaces were cytocompatible with pre-osteoblastic cells. The saliva proteomic profile, evaluated by liquid chromatography coupled with tandem mass spectrometry, was slightly changed by zirconia, with more proteins adsorbed. KOH@Zr8 group notably absorbed proteins crucial for implant biological responses, like albumin and fibronectin. Incorporating ZrO2 improved the mechanical and electrochemical behavior of Ti surfaces, as well as modulated biofilm composition and provided suitable biological responses.

Enhanced Antibacterial Properties of Titanium Surfaces through Diversified Ion Plating with Silver Atom Deposition.

In this study, we investigate the antibacterial effect of silver atoms implanted into a thin surface layer of titanium at low energies using an alternative ion plating technology called Diversified Ion Plating. Silver atoms were incorporated into titanium samples using reactive low-voltage ion plating at 2 keV and 4 keV. Surface modifications and morphology were evaluated using wettability, profilometry measurements, and energy-dispersive spectroscopy. For a precise determination of the quantity and depth of implanted silver atoms on titanium surfaces, a combination of experimental techniques such as Rutherford Backscattering Spectrometry along with Monte Carlo simulations were utilized. To assess the antibacterial effects of the silver atoms incorporated into pure titanium surfaces, bacterial suspension immersion tests were performed with a standard strain of Staphylococcus aureus (ATCC 12600). The outcomes indicate that titanium surfaces implanted with silver atoms were more effective in inhibiting the growth of Staphylococcus aureus than pure titanium surfaces. Better results were found when the deposition was performed at 4 keV, indicating that a deeper implantation of silver, spanning a few nanometers, can result in a longer and more effective release of silver atoms. These findings suggest the potential for the development of new, cost-effective biomaterials, paving the way for improved implant materials in various health-related applications.

Nitriding Titanium by Plasma Ion Implantation: Surface Properties and Initial Osteoblast Cell Response

This in vitro study aimed to investigate the effect of plasma ion implantation nitriding on titanium's surface properties and initial cell response. Grade 4 titanium discs (12.7 × 2 mm) were blasted with aluminum oxide particles to create moderately rough surfaces. The experimental discs (TiN) were nitrided using the plasma ion implantation technique in a vacuum chamber. Surface characterization was performed using laser confocal microscopy, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Surface wettability was assessed by measuring the contact angle of a sessile drop using a goniometer. Human osteoblast cells were seeded on the discs to evaluate cell attachment and proliferation at 1, 3, 5, and 7 days of culture using a tetrazolium compound assay. Alkaline phosphatase (ALP) activity was measured at day 7 to assess cell differentiation. Cell morphology was examined by scanning electron microscopy (SEM) and confocal laser scanning microscopy. The TiN group exhibited similar micro-roughness to the control group; however, it displayed a higher density of nanostructures, increased nitrogen content, and slightly improved wettability. Cell proliferation and ALP activity were similar between the groups after seven days of culture. In conclusion, plasma ion implantation nitriding enhances surface nanofeatures and wettability without compromising the biocompatibility of titanium, making it a promising surface modification technique for dental and orthopedic implants.

Iodine-doped TiO2 nanotube coatings: a technique for enhancing the antimicrobial properties of titanium surfaces against Staphylococcus aureus

BackgroundImplant-related infections are a challenging complication of orthopedic surgery, primarily due to the formation of bacterial biofilms on the implant surface. An antibacterial coating for titanium implants was developed to provide novel insights into the prevention and treatment of implant-related infections.MethodsTitanium plates were coated with TiO2 nanotubes by anodization, and iodine was doped onto the coating via electrophoretic deposition. The obtained plates were characterized using a range of analytical techniques. Subsequently, Staphylococcus aureus was inoculated onto the surfaces of untreated titanium plates (control group), TiO2-nanocoated titanium plates (TiO2 group), and iodine-doped TiO2-nanocoated titanium plates (I-TiO2 group) to compare their antibacterial properties.ResultsTwenty-four hour in vitro antimicrobial activity test of the I-TiO2 group against Staphylococcus aureus was superior to those of the other groups, and this difference was statistically significant (P < 0.05).ConclusionsThis coating technology provides a new theoretical basis for the development of anti-infective implants against Staphylococcus aureus in orthopedics.

Comprehensive Analysis of Titanium Oxide Nanoparticle Size and Surface Properties on Neuronal PC-12 Cells: Unraveling Cytotoxicity, Dopaminergic Gene Expression, and Acetylcholinesterase Inhibition.

Titanium oxide nanoparticles can penetrate the blood-brain barrier, infiltrate the central nervous system, and induce neurotoxicity. One of the most often utilized nanoparticles has been investigated for their neurotoxicity in many studies. Nonetheless, there remains an unexplored aspect regarding the comparative analysis of particles varying in size and nanoparticles of identical dimensions, both with and devoid of surface coating. In the current study, we synthesized two differently sized nanoparticles, TiO2-10 (10 nm) and TiO2-22 (22 nm), and nanoparticles of the same size but with a polyvinylpyrrolidone surface coating (TiO2-PVP, 22 nm) and studied their toxic effects on neural PC-12 cells. The results highlighted significant dose- and time-dependent cytotoxicity at concentrations ≥10 μg/mL. The exposure of TiO2 nanoparticles significantly elevated reactive oxygen and nitrogen species levels, IL-6 and TNF-α levels, altered the mitochondrial membrane potential, and enhanced apoptosis-related caspase-3 activity, irrespective of size and surface coating. The interaction of the nanoparticles with acetylcholinesterase enzyme activity was also investigated, and the results revealed a dose-dependent suppression of enzymatic activity. However, the gene expression studies indicated no effect on the expression of all six genes associated with the dopaminergic system upon exposure to 10 μg/mL for any nanoparticle. The results demonstrated no significant difference between the outcomes of TiO2-10 and TiO2-22 NPs. However, the polyvinylpyrrolidone surface coating was able to attenuate the neurotoxic effects. These findings suggest that as the TiO2 nanoparticles get smaller (towards 0 nm), they might promote apoptosis and inflammatory reactions in neural cells via oxidative stress, irrespective of their size.

Physical-chemical influences and cell behavior of natural compounds on titanium dental surfaces.

The present study evaluated the influence of carvacrol, terpinene-4-ol, and chlorhexidine on the physical-chemical properties of titanium surfaces, cell viability, proliferation, adhesion, and spreading of fibroblasts and osteoblasts in vitro. Titanium surfaces (Ti) were treated with Carvacrol (Cvc), Terpinen-4-ol (T4ol), Chlorhexidine (CHX), DMSO, and ultrapure water (Control group). Physical-chemical modifications were evaluated by surface wettability, the surface free energy (SFE) calculated from the contact angle values using the Owens-Wendt-Rabel-Kaeble (OWRK) equation, scanning electron microscopy (SEM) and energy dispersive spectrometry probe (EDS) system. Cells were seeded onto Ti-treated surfaces and incubated for 24 h and 72 h, then evaluated by Alamar blue assay and fluorescence microscopy. Surfaces treated with Cvc and T4ol showed the presence of Na, O, and Cl. All surfaces showed hydrophilic characteristics and SFE values between 5.5 mN/m and 3.4 mN/m. On the other hand, EDS peaks demonstrated the presence of O and Cl after CHX treatment. A reduction of cell viability and adhesion was noted on titanium surfaces treated with CHX after 24 and 72h. In conclusion, the results indicate that the decontamination with Cvc and T4ol on Ti surfaces does not alter the surface proprieties and allows an adequate interaction with cells involved in the re-osseointegration process such as fibroblasts and osteoblasts.

Can polyphenolic surface modifications prevent fungal colonization of titanium dental implants?

Oral biofilms can be a major health problem causing infections and chronic inflammation of mucosal tissue. While much effort is put in the investigation of bacteria in biofilms, the role of fungi is often neglected, despite Candida albicans playing a key role in the formation of multispecies oral biofilms. With the rise of antibiotic resistance, new strategies to reduce microbial growth need to be found. Therefore, plant derived polyphenolic molecules have been suggested to reduce both adhesion and growth of pathogenic bacteria and fungi. In this study, we investigated the use of polyphenolic coatings to reduce adhesion and biofilm formation of C. albicans BWP17 on titanium implants. Tannic acid and pyrogallol coatings altered the hydrophobic and charge properties of titanium surfaces, and both compounds were gradually released as active molecules over time. Despite such effects, we found no significant inhibition on growth and biofilm formation of C. Albicans, indicating that the release of active molecules from the coatings did not reach relevant inhibitory concentrations. However, a potential antibiofilm effect was observed by the pH-dependent disassembly of the polyphenolic layer, which caused the biofilm to detach. Hence, further efforts are required to create tailored implant surfaces, which sustainably reduce microbial growth and adhesion.

Ion induced effects and defects on surface, structural and mechanical properties of Ni ion irradiated titanium

Abstract Effect of 2 MeV Ni+ ion beam irradiation with varying fluences on the surface, structural, and mechanical characteristics of titanium will be explored. For this objective, titanium targets were exposed to nickel ions obtained from a pelletron linear accelerator with 2 MeV energy and various fluences extending from 3 × 1012 to 7 × 1015 ions/cm2. Penetration features and damage evolution of 2 MeV Ni-ion in titanium have been estimated by employing SRIM-2013 software. Various characterization tools were employed to confirm the modifications in the ion beam irradiated targets. The surface and crystallographic variations of ion beam irradiated targets were explored by employing a scanning electron microscope (SEM) and X-ray diffractometer (XRD). Tensile testing and microhardness analysis was performed by utilizing a software-controlled 50 KN universal tensile testing machine and Vickers’s hardness tester, respectively. The SEM analysis represents random and irregularly distributed sputter morphology for lower ion fluences. With the increase of ion fluence, the pores keep growing radially while the growth rate slows down. At the highest ion fluence, localized melting, evaporation and expulsion of surface material were recorded at the irradiated zone. The X-ray diffraction analysis revealed no additional phases to be developed in the Ni-ion treated titanium. However, a variation in the peak intensity and slight angle/position shifting was reported, which depicts the creation of ion-induced stresses and defects. The mechanical testing results indicated the variations in the mechanical characteristics (yield stress, ultimate tensile stress, hardness etc.) of irradiated titanium. The hardness, yield stress and ultimate tensile strength increased monotonically with the increase of ion fluence. The reported modifications in the mechanical characteristics of irradiated titanium are in good accordance with structural and surface modifications. The stated changes in the irradiated titanium are ascribed to the development of ions induced stress as well to creation, augmentation/expansion, recombination, and annihilation of the ion-induced defects.

Chlorhexidine-grafted phenolamine coating to improve antibacterial property of the titanium surface

To investigate the physicochemical properties of pure titanium surface grafted with chlorhexidine (CHX) by phenolamine coating, and to evaluate its antibacterial activity and osteoblast-compatibility in vitro. Control group was obtained by alkali and thermal treatment, and then immersed in the mixture of epigallocatechin-3-gallate/hexamethylene diamine (coating group). Phenolamine coating was deposited on the surface, and then it was immersed in CHX solution to obtain the grafted surface of CHX (grafting group). The surface morphology was observed by scanning electron microscope, the surface element composition was analyzed by X-ray photoelectron spectroscopy, and the surface hydrophilicity was measured by water contact angle test. Live/dead bacterial staining, nephelometery, and inhibition zone method were executed to evaluate the antibacterial property. Cytotoxicity was evaluated by MTT assay and cell fluorescence staining. Bacteria-MC3T3-E1 cells co-culture was conducted to evaluate the cell viability on the samples under the circumstance with bacteria. Scanning electron microscope observation results showed that deposits of coating group and grafting group increased successively and gradually covered the porous structure. X-ray photoelectron spectroscopy results showed the peak of N1s enhanced and the peak of Cl2p appeared in grafting group. Water contact angle test results showed that the hydrophilic angle of three groups increased in turn, and there was significant difference between groups ( P<0.05). Live/dead bacteria staining results showed that the grafting group had the least amount of bacteria adhered to the surface and the proportion of dead bacteria was high. The grafting group had a transparent inhibition zone around it and the absorbance ( A) value did not increase, showing significant difference when compared with control group and coating group ( P<0.05). MTT assay and cell fluorescence staining results showed that the number of adherent cells on the surface of the grafting group was the least, but the adherent cells had good proliferation activity. Bacteria-cell co-culture results showed that there was no bacteria on the surface of grafting group but live cells adhered well. CHX-grafted phenolamine coating has the ability to inhibit bacterial adhesion and proliferation, and effectively protect cell adhesion and proliferation in a bacterial environment.

Effect of a neodymium-doped yttrium aluminium garnet laser on the physicochemical properties of contaminated titanium surfaces and macrophage polarization.

The objective of this study was to evaluate the changes in the physical and chemical properties of titanium surfaces contaminated by a Nd:YAG laser with different levels of energy and the regulation of macrophage polarization. The titanium specimens were divided into four groups. The blank control group consisted of the above-mentioned contaminated titanium specimens, and the conditioned control group consisted of sandblasted and acid-etched (SLA) titanium surfaces. The blank control and condition control groups were sealed and preserved in a sterile dark box. There were two experimental groups treated with the Nd:YAG laser-one with 0.5W and the second with 1.0W. Surface characteristics were evaluated using scanning electron microscopy, surface profilometry, and contact angle assays. The macrophage viability and proliferation of mouse RAW246.7 were analysed, and the macrophage surface markers, macrophage cytokines, and inflammatory and anti-inflammatory genes were expressed. The Nd:YAG laser increased the hydrophilicity and roughness of the titanium surface after decontamination. Fewer RAW264.7 cells were observed on the titanium surface after Nd:YAG decontamination than on the contaminated titanium surface expressing the M1-type macrophage marker CCR7, whereas more cells were observed after decontamination than on the contaminated titanium surface expressing the M2-type macrophage marker CD206. Following Nd:YAG laser treatment, the secretion of the inflammatory cytokines IL-1β and TNF-α by RAW264.7 cells on the titanium surface was decreased, whereas the secretion of the anti-inflammatory cytokines IL-4 and IL-10 was increased. RAW264.7 cells cultured for 3days on the titanium surface after Nd:YAG decontamination treatment expressed significantly reduced levels of the inflammation-related genes IL-1β, TNF-α, IL-6 and iNOS. The expression of the anti-inflammatory genes Arg-1, IL-4, IL-10 and TGF-β by RAW264.7 cells was significantly up-regulated after 3days of incubation on the titanium surface after Nd:YAG decontamination treatment. The Nd:YAG laser increased the hydrophilicity and roughness of the titanium surface after decontamination, and this change inhibited M1-type macrophage polarization and promoted M2-type macrophage polarization.

The response of bioactive titanium surfaces with different structure to UVC-irradiation to eliminate the negative effect on biological properties during aging time

The biological aging of titanium implants affects the service lifetime negatively in clinical applications, and Ultraviolet (UV) irradiation is an applicable method to overcome the biological aging. This study investigated the changes in surface characteristics and biological properties of bioactive titanium surfaces with different structure and topography after Ultraviolet C (UVC) irradiation. The bioactive titanium surfaces were prepared by anodizing (AO), sandblasting and acid-etching (SLA), acid-alkali etching (AA), alkali-heat etching (AH) methods. Samples were stored at dark for 7 weeks to simulate biological aging process and then irradiated by UVC for 2 h. The results showed that the hydroxyl groups (Ti-OH) on surfaces, which are crucial to enhance the biological properties, were easier to be generated on AO surfaces by UVC-irradiation, owing to a mixture of anatase and rutile on surfaces. UVC-irradiation had the strongest effect on AO surfaces to enhance the bioactivity in bone-like apatite deposition and better biocompatibility in mesenchymal stem cells (MSCs) attachment and proliferation. Therefore, titanium surfaces with a mixture phase of anatase and rutile have the potential to effectively utilize the benefits of UVC-irradiation to overcome the negative effects of the biological aging and have a promising clinical application prospect.

Development and characterization of bioglass incorporated plasma electrolytic oxidation layer on titanium substrate for biomedical application

Abstract In this research, the growth of bioglass (BG) (45S5) incorporated oxide layer via plasma electrolytic oxidation (PEO) method was studied with respect to different sodium hydroxide (NaOH) concentrations (0.1, 0.3, 0.5, and 0.7 M). The voltage response during the deposition process was highly dependent on the electrolyte concentration. Large sparks were recorded at the lowest electrolyte concentration. The result also showed that the increment of electrolyte concentration improved the thickness and mechanical properties of BG-coated pure titanium (TI) surfaces via the PEO process. However, the morphological investigation showed that the coating formation and the uniformity of coating distribution are dependent on the optimum concentration of the electrolyte. This study demonstrates the feasibility of the PEO method in producing a uniform bio-functional coating for biomedical applications.

Wettability of implant surfaces: Blood vs autologous platelet liquid (APL)

Physicochemical properties of titanium surfaces, such as wettability, influence protein binding, cell adhesion and proliferation, therefore osseointegration. The objective of this study was to investigate the wetting behaviour of two titanium surfaces, sandblasted and double acid etched (group S/E) and sandblasted (group S), using blood and Autologous Platelet Liquid (APL). Surface morphology and roughness were investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The static contact angle (CA) was assessed with the sessile drop technique. The work also evaluates, with SEM observation, the fibrin clot structure that develops from blood and APL, knowing that a greater clot, firmly attached to an implant can facilitate cell migration to the implant interface. Both surfaces exhibited a hydrophobic behaviour, regardless of the wetting liquid used, but the S surface showed higher CA values for both the wetting fluids used. Lower CA values on the S/E surface are attributable to the different surface energy, which depends on different surface topography (the S surfaces were rougher) and on chemical composition. No statistically significant differences between the values of CA of blood and APL were found on the same surfaces. The clot obtained from whole blood differs from the APL clot due to a different cellular composition and fibrin density.

Physicochemical properties and in vitro osteocompatibility of different titanium surfaces stored in a saline solution

Objective. The study aimed to investigate the physicochemical properties of titanium surfaces with different morphologies stored in a saline solution and their effects on osteoblast behavior. Methods. Freshly prepared commercial pure titanium (cp-Ti), acid-etching titanium (SLA-Ti) and nanowire titanium (NW-Ti) were stored in 0.9% and 10% NaCl solutions, and exposure to air and double-distilled water were used as controls. After storage for two weeks, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), optical contact angle instrument, and optical profilometer were used to analyze the micro-morphology, elemental composition of the samples, contact angle and surface roughness. BCA protein kit was used to detect the protein adsorption capacity of the three titanium surfaces under the different storage conditions. MC3T3-E1 osteoblast-like cells were cultured on the titanium surfaces. The proliferation, adhesion, alkaline phosphatase activity, and osteogenic differentiation of MC3T3-E1 cells were assessed using CCK-8, laser confocal microscope (CLSM), alkaline phosphatase (ALP) assay, and western blotting. Results. SEM results indicated that the storage conditions did not affect the micromorphology of the titanium surfaces. The XPS and contact angle determination results suggested that cp-Ti, SLA-Ti, and NW-Ti stored in NaCl solutions showed less carbon contamination, higher hydrophilicity. The roughness results showed that the air groups and 10% NaCl had higher roughness. The protein adsorption capacity of the three titanium surfaces was significantly improved under storage in 0.9% NaCl. The proliferation activity of osteoblasts on the three titanium surfaces was not different from the control groups after storage in 0.9% NaCl solution. However, the results of the in vitro study suggested that the cell adhesion capacity and the expression of ALP and the osteogenic-related proteins Runx2, Osterix, and Osteocalcin improved after storage in 0.9% NaCl solution. Conclusions. The storage of the different types of titanium surfaces in 0.9% NaCl solution could effectively reduce carbon contamination, maintain good hydrophilicity, improve the roughness and make the environment conducive to the differentiation of osteoblasts.

Formation of Titanium Nitride, Titanium Carbide, and Silicon Carbide Surfaces by High Power Femtosecond Laser Treatment.

Coatings based on titanium nitrides, titanium carbides and silicon carbides can optimize the surface properties of titanium or silicon for various applications ranging from biocompatibility to chemical stability and durability. Here, we investigated a high power (100 W) high pulse repetition rate femtosecond laser process (λ=1030 nm, τ=750 fs, f=1 MHz) for the treatment of titanium and silicon in atmospheres of argon, nitrogen, methane, ethene and acetylene. In a nitrogen atmosphere, a homogeneous coating of TiON is formed on titanium. In an ethene/argon atmosphere coatings of TiOC and SiC are formed on Ti and Si, respectively. The process allows a fast surface transformation with a process rate of 0.33 cm2 s-1 and a high spatial resolution below 0.5 mm with a minimal heat affected zone at the same time. In contrast to low repetition rate femtosecond laser processed samples, the surfaces are more robust against mechanical impact. At the same time, the surfaces reveal a distinct microstructure in comparison to coatings obtained by vapor deposition techniques.

Surface modification strategies to improve titanium hemocompatibility: a comprehensive review.

Titanium and its alloys are widely used in different biomaterial applications due to their remarkable mechanical properties and bio-inertness. However, titanium-based materials still face some challenges, with an emphasis on hemocompatibility. Blood-contacting devices such as stents, heart valves, and circulatory devices are prone to thrombus formation, restenosis, and inflammation due to inappropriate blood–implant surface interactions. After implantation, when blood encounters these implant surfaces, a series of reactions takes place, such as protein adsorption, platelet adhesion and activation, and white blood cell complex formation as a defense mechanism. Currently, patients are prescribed anticoagulant drugs to prevent blood clotting, but these drugs can weaken their immune system and cause profound bleeding during injury. Extensive research has been done to modify the surface properties of titanium to enhance its hemocompatibility. Results have shown that the modification of surface morphology, roughness, and chemistry has been effective in reducing thrombus formation. The main focus of this review is to analyze and understand the different modification techniques on titanium-based surfaces to enhance hemocompatibility and, consequently, recognize the unresolved challenges and propose scopes for future research.

Optimization of Electrolysis Conditions for Ti Film Electrodeposition from LiF – LiCl Eutectic Molten Salt

1. IntroductionTitanium is known as a metal which has excellent properties such as high specific strength and high corrosion resistance. However, there are two problems that prevent widespread use of titanium. One is the high smelting cost and the other is the poor workability. As a method to solve these problems, titanium plating is an attractive technique because superior surface properties of titanium can be utilized. For some applications, physical vapor deposition (PVD) is practically used as a titanium plating method. However, the PVD method has high plating cost and can be used for only simple-shaped substrates. On the other hand, electrodeposition of titanium in high-temperature molten salt is a promising plating method which is expected to have lower cost and can be used for complex shaped substrates. Accordingly, there have been many reports on the titanium electrodeposition in high-temperature molten salts [1–3].We have already reported the electrochemical behaviors of Ti(III) ions and the electrodeposition of titanium in KF–KCl and LiF–LiCl molten salts [4–7]. Furthermore, we found that LiF–LiCl has an advantage for electrodepositing smooth titanium films due to its lower melting point (774 K at the eutectic composition [8]); smoother titanium films were obtained at lower temperature by suppressing grain growth of titanium [9]. Thus, in the present study, we investigated the effect of electrolysis conditions such as current density and concentration of Ti(III) ions on smoothness of titanium films in LiF–LiCl eutectic molten salt.2. ExperimentalThe experiments were conducted in LiF–LiCl eutectic molten salt in an Ar glove box at 823 K. Li2TiF6(0.50–5.0 mol%) and Ti sponge (0.33–3.3 mol%) were added to the bath and Ti(IV) ions were converted to Ti(III) ions by comproportionation reaction. Ni plate, Mo flag, and Au flag electrodes were used as the working electrode. The counter and reference electrodes were Ti rods. The potential of the reference electrode was calibrated by Cl2/Cl− potential measured at a glass-like carbon rod electrode. Samples were prepared by galvanostatic electrolysis of Ni plate substrates. The samples were analyzed by SEM/EDX after washing with distilled water and 1M Al(NO3)3 aqueous solution to remove adhered salts.3. Result and DiscussionThe electrodeposition was carried out by changing the added amounts of Li2TiF6from 0.50 to 5.0 mol% and Ti sponge from 0.33 to 3.3 mol%. The cathodic current density was also varied from 25 to 1000 mA cm−2. The surface roughness of the obtained samples was measured by SEM. As a result, smooth Ti films were obtained at high Ti(III) concentrations and low current densities. As a typical example of the smooth film, Fig. 1 shows an appearance of the sample prepared at 50 mA cm−2 and 60 C cm−2 after addition of 3.0 mol% Li2TiF6and 2.0 mol% Ti sponge. The electrodeposited titanium film had metallic luster. Fig. 2 shows a cross-sectional SEM image of the film, indicating the smooth and compact deposit.In the poster session, the solubility of Ti(III) ions will be presented. Also, the effects of Ti(III) ion concentration and cathodic current density on the morphology will be discussed.AcknowledgementThe present address of Kouji Yasuda is Graduate School of Engineering, Kyoto University.

Analysis of the mechanical and physicochemical properties of Ti-6Al-4 V discs obtained by selective laser melting and subtractive manufacturing method.

The surface properties of titanium and its alloys are commonly modified by different techniques, including additive manufacturing (AM), to improve the osseointegration of dental implants. The aim of this study was to evaluate and compare the wettability, topography, chemistry, and structure of titanium-aluminum-vanadium (Ti-6Al-4 V) discs fabricated by selective laser melting (SLM) and subtractive manufacturing (conventional machining). Three different groups were evaluated: selective laser melting (SLM); conventional machining with H3 PO4 + NaOH surface treatment (CM + ST); and conventional machining without surface treatment (CM), including analysis of wettability and roughness, morphological and chemical analyses by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX), and structural characterization analysis by computed tomography (micro-CT), and X-ray diffraction (XRD). The results showed that SLM surface had higher roughness (9.09 ± 1.94 Ra; 51.93 ± 11.59 Rz; 11.03 ± 1.95 Sa) and lower wettability (103.23° ± 13) than CM (0.06 ± 0.01 Ra; 0.42 ± 0.078 Rz; 0.07 ± 0.01 Sa) (76.95° ± 4.18) and CM + ST (0.17 ± 0.38 Ra; 0.88 ± 0.15 Rz; 0.18 ± 0.04 Sa) (18.55° ± 6.47) (p < 0.05). SEM images also proved the higher roughness of SLM surface, and CM + ST discs showed a topography resembling a sponge, characteristic of the nanometric treatment applied. EDX and XRD found no differences between the different surfaces, and micro-CT demonstrated the solid characteristic of the SLM disc. Compared with conventional machining, the SLM technique resulted in higher roughness and lower wettability. Meanwhile, the chemical properties and structure of the titanium alloy was not altered by the technique.

NGF-CS/HA-coating composite titanium facilitates the differentiation of bone marrow mesenchymal stem cells into osteoblast and neural cells

Dental implant is the most effective way to repair the defect or absence of dentition. Currently, the modification in titanium surface properties has become a hot topic in the study of oral implantology. However, more suitable titanium surface coating still needs to be further explored. We prepared the nerve growth factor-chondroitin sulfate/hydroxyapatite (NGF-CS/HA)-coating composite titanium by modified biomimetic method. We also observed the surface morphology, thickness, surface adhesion and component analysis of NGF-CS/HA-coating composite titanium by scanning electron microscope, and the release of NGF was also identified via ELISA assay. Besides, the identification of bone marrow mesenchymal stem cells (BMSCs) was conducted through alizarin red staining, oil red O staining and fluorescence detection. and the osteogenesis differentiation and neuronal differentiation-related genes were determined by RT-qPCR assay. The surface of NGF-CS/HA coating with the 65.4 ± 6.4 μm thickness presented a porous network, and the main components of NGF-CS/HA coating were Ti and HA, and maintained the activity and release of NGF. Besides, we successfully obtained and identified BMSCs, and proved that NGF-CS/HA-coating composite titanium could notably upregulated the expression levels of the osteogenesis differentiation and neuronal differentiation-related genes and proteins in BMSCs. In conclusion, NGF-CS/HA-coating composite titanium has significant promoting effects on the differentiation of BMSCs into osteoblast and neural cells.