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Despite numerous studies on various surface modifications on titanium and its alloys, it remains unclear what kind of titanium-based surface modifications are capable of controlling cell activity. This study aimed to understand the mechanism at the cellular and molecular levels and investigate the in vitro response of osteoblastic MC3T3-E1 cultured on the Ti-6Al-4V surface modified by plasma electrolytic oxidation (PEO) treatment. A Ti-6Al-4V surface was prepared by PEO at 180, 280, and 380 V for 3 or 10 min in an electrolyte containing Ca 2+ /P i ions. Our results showed that PEO-treated Ti-6Al-4V-Ca 2+ /P i surfaces enhanced the cell attachment and differentiation of MC3T3-E1 compared to the untreated Ti-6Al-4V control but did not affect cytotoxicity as shown by cell proliferation and cell death. Interestingly, on the Ti-6Al-4V-Ca 2+ /P i surface treated by PEO at 280 V for 3 or 10 min, MC3T3-E1 showed a higher initial adhesion and mineralization. In addition, the alkaline phosphatase (ALP) activity significantly increased in MC3T3-E1 on the PEO-treated Ti-6Al-4V-Ca 2+ /P i (280 V for 3 or 10 min). In RNA-seq analysis, the expression of dentin matrix protein 1 (DMP1), sortilin 1 (Sort1), signal-induced proliferation-associated 1 like 2 (SIPA1L2), and interferon-induced transmembrane protein 5 (IFITM5) was induced during the osteogenic differentiation of MC3T3-E1 on the PEO-treated Ti-6Al-4V-Ca 2+ /P i . DMP1 and IFITM5 silencing decreased the expression of bone differentiation-related mRNAs and proteins and ALP activity in MC3T3-E1. These results suggest that the PEO-treated Ti-6Al-4V-Ca 2+ /P i surface induces osteoblast differentiation by regulating the expression of DMP1 and IFITM5. Therefore, surface microstructure modification through PEO coatings with Ca 2+ /P i ions could be used as a valuable method to improve biocompatibility properties of titanium alloys.

The purpose of this study was to investigate electrochemical analysis of nano- and micro-sized pore formed Ti-6Al-4V alloys in solution containing Ca, P, Mn and Si ions via plasma eletrolytic oxidation for bio-implant materials. The coatings were produced on Ti-6Al-4V alloy for dental implant using the plasma electrolytic oxidation (PEO) method in electrolytes with the various concentration of 0, 5, and 20% Mn and Si, respectively. Electrochemical potentiodynamic polarization and AC impedance behaviors were carried out in 0.9% NaCl solution at 36.5 ± 1 °C using potentiostat (Potentiostat, EG&G, 362) and electrochemical impedance spectroscope (EIS, EG&G, 1025). The potentiodynamic polarization test with a scan rate of 1.667 mV s -1 was carried out from -1500 mV to 2000 mV. The frequency range used for EIS was 10²-10 5 Hz. The amplitude of AC signal was 10 mV and 5 points per decade was used. From the potentiodynamic polarization test, PEO treated alloy in electrolyte containing Ca, P, Mn, and Si show a lower corrosion potential than that on the bulk surface. In the case of Mn and Si doped surface, the corrosion resistance increase compared to non-doped surface with Mn and Si elements, and the current density was lower than that of the bulk surface. From the AC impedance test, in the case of Mn and Si doped surface, polarization resistance values were higher than other specimens, and nano- and micro-sized pores were covered with corrosion product consisted Mn and Si elements.

In this study, functional elements coatings on Ti-6Al-4V alloy by plasma electrolytic oxidation for biomaterials were studied using various experimental techniques. For this study, Ti-6Al-4V ELI disk (grade 5, Timet Co. Ltd., Japan diameter; 10 mm) were used as the substrate for PEO treatment in the electrolyte containing Ca, P, Si, Zn, and Mn ions. The PEO treatment was performed using a pulsed DC power supply at 280 V for 3 min. The PEO-treated surface was observed with field-emission scanning electron microscope (FE-SEM), and energy dispersive X-ray spectrometry (EDS; Oxford ISIS 310, England), Image Analyzer software, and X-ray diffractometer (TF-XRD, X'pert Philips, Netherlands). The number of pores increases, as the Zn ion content increases. And the number of pores decrease, as the Mn ion content increases. The addition of Zn and Mn ions affects the number and size of pores and the area occupied by the pores. Mn and Zn are distributed around pores and in the pores. Anatase and rutile peaks appear and the HA peak shifted to the left in the case of Mn and Zn ion additions.

The purpose of this study was to investigate hydroxyapatite coatings containing Mn and Si on the oxidized Ti-6Al-4V alloy for dental applications. Dental implant fixture and Ti-6Al-4V ELI disk were used as substrates for plasma electrolytic oxidation (PEO) treatment. PEO treatment was performed at 280 V for 3 min in various solutions. The surface morphologies of the specimens after PEO treatment were observed with a field-emission scanning electron microscope, energy-dispersive X-ray spectroscopy, X-ray diffractometer, and Fourier transform infrared spectroscopy. The breakdown potential for pore formation depended on the added ions in electrolytes. Rough surface with micro-pores was formed after plasma discharge in the electrolytes containing Si and Mn ions. The surface morphologies of implant fixtures were covered with manganese-silicon compounds, as Mn concentration increased. From the XRD analysis, anatase peaks decreased, as Mn and Si contents increased. From the results of FT-IR analysis, Si-HA and Mn-HA was formed on the implant surface.

In this study, we prepared magnesium (Mg) doped nano-phase hydroxyapatite (HAp) films on the TiO2 nano-network surface using electrochemical deposition method. Ti-6Al-4V ELI surface was anodized in 5 M NaOH solution at 0.3 A for 10 min. Nano-network TiO2 surface were formed by these anodization steps which acted as templates and anchorage for growth of the Mg doped HAp during subsequent pulsed electrochemical deposition process at 85 degrees C. The phase and morphologies of HAp deposits were influenced by the Mg ion concentration.

The purpose of this study was to investigate the control of nanotube morphology using various factors for dental implant. TiO2 nanotube formation on biomedical grade α+β type Ti-6Al-4V alloy was investigated using anodization technique as a function of applied DC potential (10 V to 30 V and 30 V to 10 V) and anodization time for 60 min in 1 M H3PO4 with small additions of NaF (0.5 wt.%, and 0.8 wt.%). The microstructure and phase characteristics of surface were examined by optical microscopy, field emission scanning electron microscopy and X-ray diffraction. Also, in order to observe the biocompatibility and surface roughness, wettability and atomic force microscopy of alloy was measured.

The purpose of this study was to investigate the biocompatibility of Ti-30Nb-7Ta alloy surface decorated with TiO2 nanotubes by anodization in an electrolyte containing 1 M H3PO4 and 0.8 wt.% NaF with an applied voltage of 10 V for 2 h. The anodization was carried out using a scanning potentiostat. The microstructures of alloys and morphology of the nanotubes were investigated by optical microscopy, field emission scanning electron microscopy, and X-ray diffractometry. In comparison to the Ti-30Nb-3Ta alloy, the Ti-30Nb-7Ta alloy contained a lower amount of α" phase, while the β phase was higher. In this study, we observed the formation of a spongy porous layer on the Ti-30Nb-7Ta alloy, while the Ti-30Nb and Ti-30Nb-3Ta alloys showed an absence of such a spongy layer.

The purpose of this study was to investigate nanotube nucleation phenomena on the Ti-25Ta-xZr alloys for implant materials, using an anodic titanium oxide (ATO) technique. Ti-25Ta-(0 wt.%-15 wt.%) Zr alloys were prepared using a vacuum arc-melting furnace. The Ti-25Ta-xZr alloys were then homogenized for 12 hr at 1000 degrees C, followed by water quenching. Formation of the nanotubular oxide surface structure was achieved initially on the Ti-25Ta-xZr alloys by anodization in a 1 M H3PO4 electrolyte containing 0.8 wt.% NaF at room temperature, using a potentiostat. After the first formation of the nanotubes was achieved, this initial nanotube layer was eliminated, and further anodization was carried out repeatedly. The microstructure, phase transformation, and morphology of nanotubular Ti-25Ta-xZr alloys and the process of nanotube growth using this ATO method were analyzed by X-ray diffraction, field-emission scanning electron microscopy, and energy dispersive X-ray spectroscopy. Microstructures of the Ti-25Ta-xZr alloys changed from α" phase to β phase. Nanotubes formed with the ATO technique had pit-like top holes, with thinner walls and lower contact angle, compared to the initially formed nanotubes.

Objective: To determine the effect of coating on the properties of two esthetic orthodontic nickel-titanium wires., Materials and Methods: Woowa (polymer coating; Dany Harvest) and BioForce High Aesthetic Archwire (metal coating; Dentsply GAC) with cross-section dimensions of 0.016 × 0.022 inches were selected. Noncoated posterior regions of the anterior-coated Woowa and uncoated Sentalloy were used for comparison. Nominal coating compositions were determined by x-ray fluorescence (JSX-3200, JOEL). Cross-sectioned and external surfaces were observed with a scanning electron microscope (SEM; SSX-550, Shimadzu) and an atomic force microscope (SPM-9500J2, Shimadzu). A three-point bending test (12-mm span) was carried out using a universal testing machine (EZ Test, Shimadzu). Hardness and elastic modulus of external and cross-sectioned surfaces were obtained by nanoindentation (ENT-1100a, Elionix; n  =  10)., Results: Coatings on Woowa and BioForce High Aesthetic Archwire contained 41% silver and 14% gold, respectively. The coating thickness on Woowa was approximately 10 µm, and the coating thickness on BioForce High Aesthetic Archwire was much smaller. The surfaces of both coated wires were rougher than the noncoated wires. Woowa showed a higher mean unloading force than the noncoated Woowa, although BioForce High Aesthetic Archwire showed a lower mean unloading force than Sentalloy. While cross-sectional surfaces of all wires had similar hardness and elastic modulus, values for the external surface of Woowa were smaller than for the other wires., Conclusions: The coating processes for Woowa and BioForce High Aesthetic Archwire influence bending behavior and surface morphology.

Nano- and micro-phase HA film formed on TiO2 nano-network surface by simple electrochemical treatment. The range of lateral pore size of the network specimen was about 10-120 nm on Ti surface by anodized in 5 M NaOH solution at 0.3 A for 10 min. Nano-network TiO2 surface were formed by this anodization step which acted as templates and anchorage for growth of the HA during subsequent pulsed electrochemical deposition process at 85 degrees C. The phase and morphologies of deposits HA were influenced by the electrolyte concentration. The nano needle-like precipitates formed under low SBF concentration were identified to be HA crystals orientated parallel to the c-axis direction. Increasing electrolyte concentration, needle-like deposits transferred to the plate-like and micro plate like precipitates in the case of high SBF concentration.

In this study, we investigated the electrochemical oxide nanotube formation on the Ti-35Ta-xHf alloys for dental materials. The Ti-35Ta-xHf alloys contained from 3 wt.% to 15 wt.% Hf were manufactured by arc melting furnace. The nanotube oxide layers were formed on Ti-35Ta-xHf alloy by anodic oxidation method in 1 M H3PO4 electrolytes containing 0.5 wt.% NaF and 0.8 wt.% NaF at room temperature. The surface characteristics of Ti-35Ta-xHf alloy and nanotube morphology were determined by FE-SEM, STEM, and XRD. The nano-porous surface of Ti-35Ta-xHf alloys showed in 0.5 wt% NaF solution and nanotubular surface showed in 0.8 wt% NaF solution, respectively. The highly ordered nanotube layer without regular knots was formed on the Ti-35Ta-15Hf alloy in the 0.5 wt% NaF solution compared to on Ti-35Ta-3Hf and Ti-35Ta-7Hf alloys in 0.8 wt% NaF solution. Also, the nanotube length of Ti-35Ta-xHf alloys increased as Hf content increased.

In this study, the electrochemical behavior of nano and femtosecond laser textured titanium alloy for implant surface modification has been researched using the potentiostat equipment. Cp-Ti and Ti-6Al-4V alloy, located on X-Y motorized stage, were irradiated using femtosecond laser. The corrosion properties were examined by a potentiodynamic and AC impedance test.

The effect of anodizing on corrosion resistance of Ti-xHf alloys has been investigated. Ti-xHf alloys were prepared and anodized at 120, 170 and 220 V in 1 M H(3)PO(4) solution, and crystallized at 300 and 500°C. Corrosion experiments were carried out using a potentiostat in 0.15 M NaCl solution at 36.5 ± 1°C. The Ti-xHf alloys exhibited the α' and anatase phases. The pore size on the anodized surface increases as the applied voltage is increased, whereas the pore size decreases as the Hf content is increased. The anodized Ti-xHf alloys exhibited better corrosion resistance than non-anodized Ti-xHf alloys.

Highly ordered nanotube oxide layers were developed on low rigidity quaternary beta-type Ti-35Nb-5Ta-7Zr alloy by controlled anodic oxidation in electrolyte containing 1 M H3PO4 and 0.5 wt% NaF at room temperature. The diameters of the nanotubes formed were in the range of 30 to 80 nm. Electrochemical corrosion behavior of the nanotubular alloy was studied in Ringer's solution at 37 +/- 1 degrees C using potentiodynamic polarization and AC Impedance. The result of the study showed that nanotube formation on the surface affect the passivation behavior of the quaternary alloy significantly. However the corrosion current density was considerably higher for the nanotubular alloy.

Ti-30Nb-xZr and Ti-30Ta-xNb alloys have been investigated using various methods of surface nanotube formation. Ternary Ti-30Nb-xZr (x = 3 and 15 wt%) and Ti-30Ta-xNb (x = 3 and 15 wt%) alloys were prepared by using high-purity sponge Ti (Grade 4, G&S Titanium, USA), Ta, Zr and Nb spheres. The two groups of ternary Ti alloys were prepared using a vacuum arc melting furnace. Nanotube formation was carried out with a conventional three-electrode configuration with the Ti alloy specimen, a platinum counterelectrode, and a saturated calomel (SCE) reference electrode. Experiments were performed in 1 M H3PO4 with small additions of NaF (0.1-0.8 wt%), using a potentiostat. Nanotubes formed on the surfaces of the two ternary Ti alloys were examined by field emission scanning electron microscopy, EDS and XRD. The Ti-30Ta-xZr alloys had microstructure with entirely needle-like constituents; the thickness of the needle-like alpha-phase increased as the Zr content increased. The Ti-30Nb-xZr alloys had equiaxed microstructures of the beta-phase, and increasing amounts of the needle-like alpha phase appeared at the grain boundaries of the beta-phase as the Zr content increased. The nanotubes were nucleated and grew mainly on the beta phase for the Ti-30Ta-3Zr and Ti-30Nb-3Zr alloys, which had nanotubes with uniform shape, but the nanotubes were nucleated at the alpha phase for the Ti-30Ta-15Zr and Ti-30Nb-15Zr alloys, which had nanotubes with irregular shape and diameters of two sizes. The diameter and depth of the nanotubes could be controlled, depending upon the alloy composition and composition of the surface oxide films (TiO2, Nb2O5, Ta2O5, and ZrO2). It is concluded that this research that selection of the appropriate alloying element can allow significant control of the nanotopography of these Ti alloy surfaces and that it is possible to control the surface nanotube size to promote long-term osseointegration for clinical dental or orthopedic use.

Highly ordered nanoporous and nanotubular oxide layers were developed on low-rigidity beta Ti-35Nb-5Ta-7Zr alloy by controlled DC anodization in electrolyte containing 1M H(3)PO(4) and 0.5wt.% NaF at room temperature. The as-formed and crystallized nanotubes were characterized by electron microscopy, energy-dispersive X-ray spectrometry and X-ray diffraction. The electrochemical passivation behavior of the nanoporous and nanotubular oxide surfaces were investigated in Ringer's solution at 37+/-1 degrees C employing a potentiodynamic polarization technique and impedance spectroscopy. The diameters of the as-formed nanotubes were in the range of 30-80nm. The nanotubular surface exhibited passivation behavior similar to that of the nanoporous surface. However, the corrosion current density was considerably higher for the nanotubular alloy. The surface after nanotube formation seemed to favor an immediate and effective passivation. Electrochemical impedance spectra were simulated by equivalent circuits and the results were discussed with regard to biomedical applications.

This comprehensive study conducts a systematic assessment of the mechanical and corrosion properties of titanium-based dental implant materials after plasma electrolytic oxidation (PEO) treatment in a solution containing Ca and P ions. Pure titanium, cold-worked pure titanium, and Ti-6Al-4V alloy underwent PEO treatment to enhance their surface characteristics. Through systematic analysis, we explore the wettability, surface roughness, hardness, elastic modulus, and corrosion resistance of PEO-treated titanium-based dental implant materials. FESEM and XRD were also done to scrutinize the crystalline structure and microstructural features before and after PEO treatment and corrosion testing. The results of this study indicate that the incorporation of PEO treatment in Ti-based materials has increased their properties as an improved biomaterial. Among all groups, Ti-6Al-4V + PEO was found to hold enhanced mechanical strength and corrosion resistance. These findings provide crucial insights for the advancement of implants through PEO treatment, suggesting that PEO treatment can optimize clinical outcomes in dental implant applications. • Plasma electrolytic oxidation (PEO) coatings on mechanically cold-worked titanium were researched. • Morphology of PEO coating on Ti alloy showed numerous large volcanic-like porous eruptions. • Surface of cold-worked PEO coating presented clusters of nano-scaled pores with an anatase phase. • PEO-treated Ti surface improved corrosion resistance, wettability, roughness, and mechanical properties. [ABSTRACT FROM AUTHOR]

In this work, surface observation of nanotube-formed titanium by anodization in an electrolyte containing hydroxyapatite nanoparticles was carried out using FE-SEM and analyzed by XPS in order to determine changes in the chemical states of elements through depth profiling. The anodized layer consisted of three regions: (1) a TiO 2 layer adjacent to titanium , (2) an intermediate barrier layer of TiO 2 nanotubes, and (3) a surface hydroxyapatite [HAp, Ca 10 (PO 4) 6 (OH) 2 ] layer. The nanotube-formed surface consisted of the anatase TiO 2 phase. The HAp layer that formed on the TiO 2 nanotube film grew vertically, and the electrodeposited HAp nanoparticles were distributed on the whole surface. From comparative analyses of the depth profile before Ar+ ion sputtering and after 4 keV Ar+ ion sputtering, the multilayer contained Ti, O, Ca, and P, and showed no noteworthy difference. The Ti-2p, O-1s, Ca-2p, F-1s, C-1s, and N-2s transitions were continuously detected in the multilayer as the sputtering time increased. The dominance of the Ti-2p and O-1 s peaks, both before and after the Ar+ ion sputtering, shows that the surface consists mainly of an oxidized TiO 2 layer. The Ca-2p and P-2p peaks were subsequently detected from HAp nanoparticles electrodeposited onto the TiO 2 nanotube film during an electrochemical reaction. The chemical states of calcium and phosphate in the multilayer were similar to those in HAp. • Nanoparticles created by anodization on nanotube-formed titanium were investigated. • The anodized multilayer consisted of a cell base, a barrier layer, TiO 2 nanotubes, and a hydroxyapatite layer. • Ti, O, Ca, and P in the multilayer showed no notable differences in proportions before and after Ar + sputtering. • Transitions for Ti-2p, O-1s, Ca-2p, F-1s, C-1s, and N-2s were continuously detected by XPS in the multilayer. • The chemical states of calcium and phosphate in the multilayer were similar to those in hydroxyapatite. [ABSTRACT FROM AUTHOR]

In this study, OCP powder was used for mechanical coating on the plasma electrolytic oxidized (PEO) implant surface to improve bioactivity. PEO treatment was performed on the surface of the implant using a solution mixed with calcium acetate and calcium glycerophosphate, and creates porosity through a pulsed DC power supply. For compositional analysis, energy dispersive X-ray spectrometer analysis was employed to calculate OCP content and X-ray diffractometer analysis was used to confirm the crystal structure. Also, wettability, surface roughness, hardness, elastic modulus, and corrosion resistance testing were performed. Significantly, the reduction in OCP particle size decreased, and pore filling with OCP smaller particles increased as mechanical coating time increased from 0 to 12 h. Surface and cross-sectional morphology showed the presence of OCP on the substrate. Also, surface roughness, contact angles, hardness, and elastic modulus were reduced as mechanical coating time increased. Corrosion resistance was found to be the highest for mechanical OCP coating for 6 h surface treatment on the PEO-treated CW-Ti. • Mechanical octacalcium phosphate (OCP) coatings on plasma electrolytic oxidized (PEO) titanium were researched. • OCP particle size decreased and pore filling increased as mechanical coating (MC) time increased. • Surface and cross-sectional morphology showed the presence of OCP on the substrate. • Surface roughness, contact angles, hardness, and elastic modulus were reduced as MC time increased. • Corrosion resistance of sample surface improved by mechanical OCP coatings. [ABSTRACT FROM AUTHOR]

Abstract: The deposition and morphology of hydroxyapatite (HA) nanoparticles on nanotube-formed Ti–Nb–Zr alloys for dental implants has been investigated utilizing electrochemical, field-emission scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) methods. Ti–29Nb−xZr ternary alloys with 3 and 15 wt.% Zr content were prepared by arc melting. Nanotubular oxide layers were formed on these alloys by an anodic oxidation method in 1 M H3PO4 electrolyte containing 0.8 wt.% NaF at room temperature. Hydroxyapatite coatings were deposited onto the nanotubular surfaces via an electrochemical method (pulsed current). The HA layers were well-deposited and contained features of the underlying nanotube structure; observed morphologies consisted of particles, a mixture of particles and plate-like shapes, and entirely plate-like shapes. This variation in morphology occurred with an increasing number of deposition cycles and increases in Ca and P concentrations in the electrolyte. X-ray diffraction revealed that the nanotubular coating contained the anatase form of TiO2, and FTIR indicated that the electrochemically deposited calcium phosphate layer contained HPO4 2−, PO4 3−, H2O, and OH− indicative of the HA composition. [Copyright &y& Elsevier]

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]