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This study investigates the evolving relationships and interactions between two distinct materials used in hard tissue implants: multi-walled carbon nanotubes (MWCNTs) and copper nanoparticles (Cu NPs). The surface modification of the Ti6Al4V implant substrate was achieved using hydroxyapatite (HAp) and its composite materials with MWCNTs and Cu-functionalized MWCNTs electrolytes. The plasma electrolytic oxidation (PEO) method was employed to enhance the physicochemical properties of the coatings. Incorporating MWCNTs into the HAp composite significantly improved these properties, resulting in superior overall corrosion resistance. MWCNTs effectively inhibited the corrosion process of the underlying metal substrate and reduced the formation of corrosion products. Additionally, it helped stabilize the HAp particles in the coating, reducing their dissolution in the corrosive environment. Additionally, the PEO process led to the formation of copper oxides (CuO and Cu2O) from Cu NPs, which were carefully analysed for their impact on coating properties. The antibacterial properties of the coatings were attributed to specific mechanisms of copper oxide products, including CuO and Cu2O, which generate reactive oxygen species (ROS) and induce oxidative stress in bacteria. These mechanisms, involving ion release, surface interactions, and intracellular effects, were discussed in detail to explain the observed antibacterial activity. Additionally, this study provides a detailed comparison of MWCNTs and Cu/MWCNT coatings applied on Ti6Al4V using a HAp-containing electrolyte, highlighting the physicochemical and antibacterial effects and the factors influencing these properties. The findings suggest that these composite coatings offer promising potential for enhancing the performance of dental implants, thereby contributing to better implant longevity and biocompatibility.

The focus of this study was to examine the surface, mechanical, corrosion, and bioactive characteristics of TiO2coatings doped with different grams of nanoparticles of MoS2, which were fabricated using the plasma electrolytic oxidation (PEO) technique, and the structure, morphology, surface characteristics, and corrosion resistance of MoS2and TiO2coatings were assessed. The coatings were fabricated on the Ti-6Al-4V alloy substrate using a PEO setup, with varying concentrations of MoS2nanoparticles incorporated into the electrolyte solution. FESEM, XRD, and AFM were utilized to analyze the surface characteristics of the coatings. Also, PDP and AC impedance tests were done to check corrosion properties. Raman analysis, XPS, and cell tests were also done. The findings demonstrated that incorporating MoS2nanoparticles resulted in creating a composite coating characterized by adequately increased surface energy, wettability, and improved adhesion to the substrate. The FESEM analysis revealed a uniform dispersion of MoS2throughout the TiO2matrix forming a homogeneous and compact coating structure and also doping inside the PEO pores. XRD analysis confirmed the presence of TiO2, and the addition of MoS2nanoparticles further improved the crystallinity of the TiO2coating. AFM measurements demonstrated a slight increase in surface roughness and an increase in surface hardness upon the inclusion of MoS2. Compared to pure TiO2, the TiO2coating doped with MoS2displayed superior electrochemical corrosion resistance and cell proliferation properties. Alazirin staining, ALP, and mRNA activity showed that lower MoS2content such as P–2MoS2to P–6MoS2showed better cellular differentiation properties.

The study demonstrated the Ca, P, and Zn-doped ZrO2/TiO2coating layer via plasma electrolytic oxidation (PEO) and radiofrequency magnetron sputtering (RF-MS) for improving surface characteristics and biocompatibility of Ti–6Al–4V alloy. The process involved sandblasting (SB) to create micro-scale irregularities on the alloy surface, followed by RF-MS and PEO. The coating's morphology, elemental composition, phase composition, and chemical analysis were examined by FE-SEM with energy-dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman analysis. The dual surface treatment resulted in the formation of composite coatings with TiO2, ZnO, ZrO2,and HA presence and displayed anisotropic multi-scale porous morphology while the surface texturing created by the SB process facilitated mechanical interlocking during the oxide layer growth. In the SB-Zr + PEO-Zn sample, the phase analysis indicated the strain-induced stabilization of t-ZrO2in the PEO coating layer due to the incorporation of Ca2+ions, and the formation of zinc-substituted hydroxyapatite was observed that showed enhanced roughness and wettability. Also, reduced hardness and elastic modulus (comparable to that of cortical bone) were observed due to transformation toughening under stress from t-ZrO2to m-ZrO2. The presence of TiO2, ZrO2,ZnO, and HA within the coating, all act as protective barriers in effectively reducing corrosion rates. The biological analysis demonstrated better biocompatibility, including promoting cell proliferation, cell adhesion, osteoblast differentiation, ALP activity, and mRNA expression of several osteogenic markers of the cells cultured on the SB-Zr + PEO-Zn sample. These results demonstrated the higher potential of the PEO coating system with higher biocompatibility and osseointegration ability for dental implants.

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 vitroresponse 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 Ca2+/Piions. Our results showed that PEO-treated Ti-6Al-4V-Ca2+/Pisurfaces 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-Ca2+/Pisurface 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-Ca2+/Pi(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-Ca2+/Pi. 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-Ca2+/Pisurface induces osteoblast differentiation by regulating the expression of DMP1 and IFITM5. Therefore, surface microstructure modification through PEO coatings with Ca2+/Piions could be used as a valuable method to improve biocompatibility properties of titanium alloys.

In this study, the biocompatibility and degradation behavior of a low elastic modulus Ti-35Nb-3Zr alloy were investigated and compared with that of the conventional orthopedic and dental implant materials, i.e., commercially pure titanium (Cp-Ti) and Ti-6Al-4V alloy. The biocompatibility test results suggested that cells proliferate equally well on Ti-35Nb-3Zr and Cp-Ti. The degradation rates of Cp-Ti and Ti-6Al-4V were ∼68% (p< 0.05) and ∼84% (p< 0.05) lower as compared to Ti-35Nb-3Zr, respectively. Interestingly, the passive current density (ipass (1000mv)) of the Ti-35Nb-3Zr alloy was ∼29% lower than that of Cp-Ti, which suggests that the alloying elements in the Ti-35Nb-3Zr alloy have contributed to its passivation behavior. Nanosurface engineering of the Ti-35Nb-3Zr alloy, i.e., a two-step electrochemical process involving anodization (producing nanoporous layer) and calcium phosphate (CaP) deposition, decreased the degradation rate of the alloy by ∼83% (p< 0.05), and notably, it was similar to the conventional Ti-6Al-4V alloy. Hence, it can be suggested that the nanosurface-engineered low elastic modulus Ti-35Nb-3Zr alloy is a promising material for orthopedic and dental implant applications.

Micropore and nanotube formation on the Ti oxide are important to improve the cell adhesion and proliferation in clinical use. In this study, nanotube and micropore of Ti alloy for biocompatibility have been investigated using FE-SEM and XRD. Ternary alloys were prepared by using high purity sponge Ti Ta, Zr and Nb sphere (99.95% wt.%). Two-step anodizing was used for surface modification of the titanium alloys. Micropore formation was first performed using a potentiostat in 1 M H3PO4 electrolyte and nanotube formation was performed in 1M H3PO4 + 0.8wt% NaF solution by using a potentiostat. The two-step anodizing process is an efficient method for forming micropores and nanotubes on the surfaces of ternary titanium alloys, and the morphology of micropore and nanotube is dependent on the alloying element and composition of ternary alloy.

Incorporation of functionalised and modified nanostructures in various biomedical applications has generated considerable research interest in recent years. The applications of nanotechnology in medicine and biomedical engineering are vast and spans areas such as implant and tissue engineering, diagnosis and therapy. The present scenario demands designing of nanotools which can respond to the needs of biological problems and prepare more efficient biomedical approaches. This article reviews recent developments in nanobiotechnology with special emphasis on load bearing implants and novel tissue engineered scaffolds. Novel research approaches in nanomedicine and major challenges to practical applications are also highlighted.

Effects of TiN, ZrN and tooth-ash coatings on the surface phenomena of Ti-(Nb, Zr, Ta, Hf) dental implant alloys with low elastic modulus has been researched by using electrochemical methods. Ti-(Nb, Ta, Zr, and Hf) alloys were fabricated and surface-coated with TiN, ZrN and tooth-ash (hydroxyapatite) using the RF-sputtering. The electrochemical behaviors of the TiN, ZrN and HA-coated dental implant fixtures were investigated using techniques such as potentiodynamic polarization analysis in 0.9% NaCl solution, as well as examine the detailed structure of these coated alloys using SEM and XRD. From potentiodynamic test of Ti-(Nb, Zr, Ta, Hf) alloy, the corrosion resistance of TiN/ZrN/tooth-ash composite coated Ti-(Nb, Zr, Ta, Hf) alloy were higher than those of the non-coated Ti-(Nb, Zr, Ta, Hf) alloy.

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In this study, AC impedance behaviors of Ti-Zr binary alloys for biomaterials have been investigated using by electrochemical impedance spectroscopy. Ti-10wt%, 20wt%, 30wt%, and 40wt% Zr alloys were prepared by arc melting and homogenized for 24 hr at 1000 °C in argon atmosphere. Phase constitutions and microstructure of the specimens were conducted by using XRD, OM and SEM. The corrosion properties of the specimens were examined through potentiodynamic test (potential range of -1500 ~ 2000 mV), AC impedance spectroscopy(100kHz~10mHz) in artificial saliva solution by potentiostat (EG&G Co, PARSTAT 2273. USA). In as-cast and homogenized Ti-xZr alloys, α-phase was identified by XRD. Microstructures were changed from lamellar structure to needle-like structure as Zr content increased. From the results of polarization behavior in the Ti-xZr alloys, it was found that the corrosion resistance was increased with increasing Zr content. From results of AC impedance spectroscopy, passive film resistance value of homogenized Ti-40Zr specimen(1.60×106 Ωcm2) showed higher than that of as-cast specimen.

The Ti-Hf alloy system forms α-β isomorphous system and does not form any intermetallic compounds, which is also beneficial for good mechanical properties. And in order to avoid the release of materials, surface modifications are generally carried out to form a TiN and ZrN layer on the surface. Electrochemical properties of TiN and ZrN coated Ti-Hf alloy by RFsputtering has been researched using various electrochemical methods. Ti-10wt%, 20wt%, 30wt%, and 40wt% Hf alloys manufactured by non consumable vacuum arc melting furnace. All the specimens were heat treatment at 1000°C for 24hr in Ar atmosphere followed by furnace cooling, respectively. The specimens were coated with TiN and ZrN respectively, by RF-magnetron sputtering method. The microstructures were conducted by using OM, EDX and SEM. The corrosion tests were carried out using potentiodynamic(PARSTAT 2273, EG&G, USA) and potentiostatic test in 0.9% NaCl solution at 36.5 ±1 °C. Microstructure clearly observed that lamellar structure translated to needle-like structure with increased Hf contents. From the analysis of TiN and ZrN coated layer analysis, TiN and ZrN coated surface showed columlar structure with 600nm and 100nm thickness, respectively. The corrosion resistance of TiN and ZrN coated Ti alloys were higher than those of the non-coated Ti-alloy in 0.9%NaCl solution, indicating better protective effect.

To evaluate the mechanical deformation phenomena of dental abutment screw after tightening and loosening, five species of abutments were selected (3i-three, Avana- two) respectively by two pieces. The abutment screws were repeatedly tightened and removed 20 times with a digital controller. Field emission scanning electron microscope (FE-SEM) was used to observe changes of each part caused by repeatedly tightening and loosening experiment. As the number of tightening and loosening was increased, the wear or distortion of hexed or squared slot that contacted with the driver tip was more severely progressed. Wear or distortion of hexed slot was more severe than that of squared slot and it was more remarkable in the titanium screw than in the gold screw. All the tested screws showed that the width in the crest of their screw thread decreased gradually as the test was proceeded.

The abutment screw loosening of dental implant system has been remained problem in restorative practices. Surface treatment of screw plays a role of preventing screw from loosening in implant screw mechanism. The purpose of this study was to investigate surface characteristics of ZrN and TiN coated dental gold-screw and Ti-screw by ion-plating method and to evaluate wear resistance, surface roughness, and film adhesion on the screw surface using field emission scanning electron microscopy(FE-SEM), energy dispersive x-ray spectroscopy(EDX), micro-diamond scratch tester, vickers hardness tester, and surface roughness tester. The surface of gold screw and GoldTite is more smoothly than ones of other kinds of non coated screw. The ZrN and TiN coated surface is more smoothly than ones of other kinds of screw. The hardness of TiN and ZrN coated surface showed higher than that of non coated surface. The TiN coated titanium screw and ZrN coated gold screw have a good wear resistance and adhesion on the surface. The surface of ZrN coated screw showed low surface roughness compared with the surface of TiN coated screw.

To investigate mechanical fitness of abutment/fixture screw interface in the internal dental implant system, internal connection type implants from AVANA(Osstem®), Bioplant(Cowell-Medi®), Dio(DIO®), Neoplant(Neobiotech®), systems were used in this study. Each group was acquired 2 fixtures at random. Two piece type abutment and one piece type abutment for use with each implant system were acquired. Screw was respectively used to hold a two piece type abutment to a implant fixture. All samples were cross-sectioned with grinder-polisher unit and all specimens were analyzed the interface phenomena between implant fixture/abutment/screw contact interfaces by using field emission scanning electron microscope(FE-SEM). Implant fixture/abutment/screw connection interfaces of internal connection systems made in Korea were in good condition. The results of the above study showed that materials and mechanical properties and quality of milling differed depending on their manufacturing companies.

The Arc melting technique was employed to synthesize the type I clathrate of Ba8Al16Si30 compound. Phase transformations during synthesis and homogenization treatment were investigated using X-ray diffraction (XRD) and thermal analysis (TG/DSC). Thermoelectric properties as functions of temperature and homogenization treatment time were evaluated in this study. Maximum ZT was 0.14 at 590K for homogenized at 1173 K for 168hrs specimen and it is strongly expected to show higher value above 600K.

In order to investigate the intergranular and pitting corrosion behavior of Fe-25Al-6Cr intermetallic compounds containing Mo, Nb and B, 11 kinds of Fe-25Al were prepared by arc melting in Ar gas, using high purity aluminum and iron. The fabricated materials were heat treated for homogenious structure and stabilization of the iron aluminides. The electrochemical methods were used for interganular and pitting corrosion. Effects of Mo, Cr, Nb and B on the repassivation current density(Ir) and the active current density(Ia) of Fe-25Al-6Cr were recorded in the following order: MoCr>Nb>B, from the highest to the lowest respectively.

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In this study, in order to fabricate dental and medical bone plates, the effects of hydroxyapatite(HA) coating made of tooth ash and TiN coating prepared by electron-beam physical vapor deposition(EB-PVD) method on corrosion resistance and surface phenomena of Ti alloyed bone plates were investigated using various test methods. The coatings were deposited on the Ti-6Al-4V alloy fabricated by using a vacuum induction furnace. The corrosion behaviors of the samples were examined through potentiodynamic method in 0.9% NaCl solutions at 36.5±1℃ and corrosion surface was observed using SEM and XPS. The surface roughness of TiN coated bone plates was lower than that of HA coated plates. The structure of TiN and HA coated layers showed the columnar structure. The corrosion potential was observed to be higher on the TiN and HA coated specimens than that of the non-coated alloy. The active current density was drastically lowered by both of TiN and HA coatings. The pit number and pit size of TiN and HA coated alloy were smaller in comparison with those of non-coated alloy. From the experimental results, it is suggested that TiN coated Ti alloy sample with rough surface has good protective propertiy against corrosion as well as HA coated bone plate alloy.

In this study, we investigated the electrochemical characteristics of TiN/ZrN multilayers on a Ti--35Ta--$x$Hf alloy by radio frequency (RF) magnetron sputtering. The Ti--35Ta--$x$Hf alloy had an $\alpha”+ \beta$ phase structure. The Ti--35Ta--15Hf alloy had a higher intensity $\beta$ phase peak than Ti--35Ta--3Hf and 7Hf alloy, which contained lower Hf content. The martensite traces disappeared with increasing Hf content and the Ti--35Ta--15Hf alloy showed an entirely equiaxed structure with a $\beta$ phase. The multilayer film was developed by alternately depositing TiN and ZrN layers on Ti--35Ta--15Hf substrates using the RF magnetron sputtering system to improve the interface properties between the coating and substrate. The uncoated specimen showed a passive region between 60 and 1300 mV with a current density of 0.38 μA/cm2, whereas, the TiN/ZrN multilayered specimen had a passive region between 210 and 1500 mV with a current density of 0.09 μA/cm2. The experimental results suggest that the as-sputtered layer coated well on the substrate. The TiN/ZrN multilayered film on Ti--35Ta--15Hf substrate exhibited better electrochemical resistance than that of the uncoated Ti--35Ta--15Hf substrate.