Bioceramic Coatings Research Articles

Surface Evaluation of Tricalcium Phosphate Bioceramic Coating on SS-316L by Electrophoretic Deposition

The development of orthopedic implant materials has become an important topic of discussion lately. The SS-316L alloy is widely used as an implant material due to its relatively low cost, corrosion resistance, and ease of production. However, metal alloys, especially SS-316L, are prone to ion release into the blood over time. Therefore, TCP or tricalcium phosphate [Ca3(PO4)2] is needed to coat the surface of SS-316L, preventing ion release into the blood and enhancing the biocompatibility of the implant material. In this study, TCP coating was applied to the SS-316L substrate using the electrophoretic deposition technique. The influence of deposition time on changes in microstructure and mechanical properties is the main focus of this study. The results of the coating technique indicate that the deposition yield increases with the deposition time. Morphological testing results show that increasing deposition time improves coating quality by increasing the thickness of the coating layer and preventing layer peeling. The coating process also reveals the accumulation of layers in certain areas and the formation of thin layers in other regions. A deposition time of 30 minutes results in a coating thickness ranging from 48.7 to 57.9 µm. Hardness testing, conducted with indentation loads of 50, 100, and 300 gf, indicates that longer deposition times and higher indentation loads during hardness testing result in reduced material hardness.

Hemocompatibility and Preangiogenic Attributes of SiBxCyNzOm Coatings for Biomedical Applications.

In current clinical practices related to orthopedics, dental, and cardiovascular surgeries, a number of biomaterial coatings, such as hydroxyapatite (HAp), diamond-like carbon (DLC), have been used in combination with metallic substrates (stainless steel, Ti6Al4V alloy, etc.). Although SiBCN coatings are widely explored in material science for diverse applications, their potential remains largely unexplored for biomedical applications. With this motivation, the present work reports the development of SiBxCyNzOm coatings on a Ti6Al4V substrate, employing a reactive radiofrequency (RF) magnetron sputtering technique. Three different coating compositions (Si0.27B0.10C0.31N0.07O0.24, Si0.23B0.06C0.21N0.22O0.27, and Si0.20B0.05C0.19N0.20O0.35) were obtained using a Si2BC2N target and varying nitrogen flow rates. The hydrophilic properties of the as-synthesized coatings were rationalized in terms of an increase in the number of oxygen-containing functional groups (OH and NO) on the surface, as probed using XPS and FTIR analyses. Furthermore, the cellular monoculture of SVEC4-10 endothelial cells and L929 fibroblasts established good cytocompatibility. More importantly, the coculture system of SVEC4-10 and L929, in the absence of growth factors, demonstrated clear cellular phenotypical changes, with extensive sprouting leading to tube-like morphologies on the coating surfaces, when stimulated using a customized cell stimulator (StimuCell) with 1.15 V/cm direct current (DC) electric field strength for 1 h. In addition, the hemocompatibility assessment using human blood samples revealed clinically acceptable hemolysis, less erythrocyte adhesion, shorter plasma recalcification, and reduced risk for thrombosis on the SiBxCyNzOm coatings, when compared to uncoated Ti6Al4V. Taken together, the present study unambiguously establishes excellent cytocompatibility, hemocompatibility, and defines the preangiogenic properties of SiBxCyNzOm bioceramic coatings for potential biomedical applications.

Effect of bioceramic powder abrasion on different implant surfaces.

Bioceramic coatings have been shown to promote bone repair, which aids in the early integration of implants. This study aimed to evaluate the influence of air abrasion with a bioceramic abrasive on the surface characteristics of different implant materials and surfaces. The dissolution of the applied treatment from the surfaces over 3 weeks was also assessed. Discs of three alloys used for dental implants were studied and compared: two types of commercially pure titanium (CpTi)/ (CpTi SLActive) and titanium-zirconia (TiZr). The tested surfaces were: CpTi control (CpC), sandblasted (SB), sandblasted and acid-etched (SBE), and CpTi SLActive®, (TiZr) Roxolid®. Three discs from each group underwent air abrasion with apatite bioceramic powders, 95% hydroxyapatite (HA)/5% calcium oxide (CaO), and 90% hydroxyapatite (HA)/10% calcium oxide (CaO). The treated discs were surface characterized by optical profilometry to obtain surface roughness, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) to compare element weight percentages of titanium, calcium, and phosphate. Dissolution was assessed using inductively coupled plasma optic emission spectrometry (ICP-OES). Bioceramic powders were deposited on all tested surfaces leading to changes in surface characteristics. The only statistically significant differences between the material groups for surface roughness were found with 95% HA/5% CaO powder in the Sp and Rp parameters (p = 0.03 and 0.04, respectively). There were no significant differences in the Ca and P wt% between all groups and powders 95% HA/5% CaO and 90% HA/10% CaO (p = 0.14, 0.18, and p = 0.15, 0.12, respectively). A non-uniform dispersion of the treatment on the surface layer was visible on all treated surfaces. The bioceramic powder continued to dissolute from the tested surfaces for 3 weeks. Bioceramic abrasion modifies implant surface characteristics, although the change in surface characteristics resulting from such treatment was not influenced by the implant material or surface treatment. Air abrasion with hydroxyapatite and calcium oxide bioceramics leaves powder deposits on the treated implant surfaces that could potentially influence the healing of implants affected by peri-implantitis.

Characteristics of Bio-ceramic Coating on Corrosion Rate of Stainless Steel 316L and Titanium (Ti-6Al-4V)

Thermal spray coating improves SS 316L corrosion resistance using biomaterials like hydroxyapatite (HA), zirconium dioxide (ZrO2), and titanium dioxide (TiO2), promoting bone binding and biological fixation. The study examined the impact of bio-ceramic coatings like HA, HA+TiO2, and HA+ZrO2 on the corrosion rate of stainless steel and titanium in Hank's Balance Salt Solution and artificial saliva media. Electrochemical testing with polarization was carried out to determine the performance of biomaterials against corrosion rates. The addition of TiO2 and ZrO2 to HA in both SS316L and Ti6Al4V materials reduced the corrosion rate more than HA. This study revealed that coating with HA, HA + ZrO2, and HA + TiO2 biomaterials results in varying thicknesses and roughness under the same spraying parameters. Bioceramic coatings on implants offer an alternative coating to improve the performance of biomaterials.

Corrosion behaviour of plasma-sprayed baghdadite bioceramic coatings reinforced with carbon nanotubes

Bioceramics have been extensively used for the restoration and replacement of hard tissues, such as bones and teeth due to their physicochemical resemblance to these tissues. This study focuses on enhancing the properties of plasma-sprayed bioceramic coatings with the addition of carbon nanotubes. The coatings deposited include hydroxyapatite, baghdadite, and baghdadite with carbon nanotube reinforcement. The effect of incorporating carbon nanotubes into baghdadite coatings is thoroughly investigated in terms of microstructural, mechanical, and electrochemical properties. Multiple characterization techniques such as scanning electron microscopy, energy dispersive spectroscopy, X-ray diffractometry, and Raman spectroscopy have been employed to reveal microstructural details, elemental composition, and phase constituents of the deposited coatings. The results indicate that baghdadite coatings exhibit higher porosity compared to hydroxyapatite coatings. However, the addition of carbon nanotubes as reinforcement into baghdadite coatings effectively reduces porosity by integrating carbon nanotubes within the inter-lamellae structure and filling voids within the inter-splat regions. This integration also mitigates common post plasma spray defects including porosity, voids, and microcracks. The incorporation of 2 wt% carbon nanotubes into the baghdadite matrix results in a substantial 80% reduction in corrosion current density(Icorr). This reduction is attributed to the combined effects of reduced porosity, and improved structural integrity due to carbon nanotubes. Furthermore, the carbon nanotubes reinforced baghdadite coatings have indicated the healthy development of the MC3T3-E1 osteoblast cell line.

A remote atmospheric pressure plasma-assisted textile functionalization process on polymeric scaffolds for bone tissue engineering

When adopting polylactic acid (PLA) nonwoven for bone tissue engineering scaffolds, the inert and hydrophobic nature of PLA leads to poor biocompatibility and osteoconductivity, and limits the efficiency of applying bioceramic coatings, such as hydroxyapatite (HAp), for surface functionalization. To tackle these issues, a remote atmospheric pressure plasma (APP) system using a bespoke Pyrex chamber and acrylic acid monomer was designed and employed to functionalize the PLA via depositing carboxylic acid functional groups onto its surface. The remote APP showed being polymeric textile-suitable with an improved efficiency on not only immobilizing carboxylic acid functional groups on the PLA nonwoven than conventional systems but also the alternate soaking process for HAp deposition. Being compared with the neat PLA, the plasma-functionalized PLA exhibited a more hydrophilic surface (from 130.49 ± 1.28° to 117.40 ± 2.53°) with a 30-day stability (from 117.40 ± 2.53° to 119.40 ± 0.75°) and showed better biocompatibility (136 % to the neat PLA) with MC3T3-E1 mouse embryonic osteoblast cells after HAp deposition. The presence of carboxylic acid functional groups and HAp (Ca/P ratio of 1.7) was also identified using X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy and a scanning electron microscope with energy dispersive X-ray analysis.

Effect of microstructure and chemical composition on cell orientation and proliferation viability of titanium alloy processed by pulse lasers

Samples with different surface microstructures and elemental composition were fabricated by pulsed lasers with different pulse duration, including the millisecond laser remelting (RE), the bioceramic coating (BC), and nanosecond laser processing (NL) samples. The morphologies, chemical elements, phases, and valences of these samples were analyzed and characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The contact angles of the samples were measured in air and under water. Their cell activity and behavior were analyzed by cell proliferation and cytoskeleton staining experiments. The results show that the hydrophilicity and aerophobicity increase after laser treatment, and the wetting behavior of underwater bubbles is strongly related to the wettability of the sample in the air. None of the samples examined in the experiment are cytotoxic. During the initial culture, the greater unevenness of the BC and NL sample surfaces hinders the initial expansion of the cells. In contrast, the cell spreading area of the ground (G) and the RE samples is larger. The inclined sidewall in the V-shaped structure weakens the energy barrier in the groove-ridge combination (NL sample), allowing cells that rarely adhere to the sidewall to adhere successfully. In addition, the orderly distribution of adhesion sites created by laser processing further promotes cell adhesion on the inclined sidewalls. When the cells have been cultured to Day 7, the NL sample forms a clear directional distribution of cells with its unique V-shaped structure mimicking the placoid scale on the shark skin surface.

In-situ synthesis and characterization of calcium phosphate coatings on rapidly solidified zirconia toughened alumina eutectic bioceramics by laser cladding

Rapidly solidified zirconia toughened alumina (ZTA) eutectic bioceramics are promising load-bearing materials that meet the needs for durability and aging resistance for biomedical applications. However, one of the major problems is their poor bioactivity which may lead to aseptic loosening after long-term service. To solve this problem, calcium phosphate (Ca-P) coatings are in-situ synthesized on rapidly solidified ZTA eutectic bioceramics by laser cladding technology with mixed powders of CaHPO4∙ 2H2O and CaCO3 after granulation as precursors. X-ray diffraction results show that Ca-P coatings are mainly composed of Ca0.2Zr0.8O1.8, AlPO4, Ca4P2O9, Ca3(PO4)2 and Ca2P2O7. The amount of calcium phosphates reaches a maximum when using a laser power of 800 W and a scanning rate of 650 mm/min. Cross-sectional morphologies and energy dispersive spectrometer analysis indicate excellent interfacial bonding between the substrate and coating. In vitro tests prove that Ca-P cladded samples can induce apatite with flake-like morphology similar to those on the bioceramic coatings cladded on titatinum alloy precipitation and promote MC3T3-E1 cell proliferation. This work reveals that laser cladding has the potential to improve the biomineralization of solidified ZTA eutectic bioceramics enabling prolonged clinical service life.

The Effects of Hydroxyapatite on the Corrosion Behaviour of AZ Series Mg Alloys

Metallic biomaterials are widely used in the orthopedic and dental applications owing to their advanced biocompatibility and sophisticated mechanical properties. Many studies are carried out to develop new alloys with high specific strength, high corrosion resistance and high biocompatibility as an alternative to present metallic biomaterials. Mg alloys are potential alloys as a biomaterial, especially because they have low density and high biocompatibility. However, especially the corrosion properties of Mg alloys need to be improved. In this study, the surfaces of AZ31, AZ61 and AZ91 alloys, which are promising as biomaterials, were coated with hydroxyapatite with high biocompatibility, and the effects of the bioceramics coatings on corrosion resistance were comprehensively investigated. Crack-free and porous surface morphologies were obtained in all bioceramic coatings and the presence of the coatings on the surfaces was supported by EDS analysis. As a result of the corrosion tests performed in SBF, it was determined that the AZ91 alloy had the highest corrosion resistance among the uncoated samples. The hydroxyapatite bioceramic coatings also improved the corrosion properties of all samples. However, among all samples, the highest corrosion resistance was obtained in the hydroxyapatite coated AZ91 alloy.

Biomechanical Properties and Corrosion Resistance of Plasma-Sprayed Fish Scale Hydroxyapatite (FsHA) and FsHA-Doped Yttria-Stabilized Zirconia Coatings on Ti–6Al–4V Alloy for Biomedical Applications

Hydroxyapatite (HA) coatings on metallic implants have been extensively used in orthopedic applications to improve tissue-implant interactions, enhance their biocompatibility, and enhance their functionality. However, the expensive synthetic HA is the most widely used bioceramic for implant coatings, leading to high implants costs. Hence, this research explored the potential of an inexpensive biogenic HA derived from fish scales and FsHA/yttria-stabilized zirconia (YSZ) bioceramic coatings on a Ti–6Al–4V alloy as an alternative to synthetic HA coatings. The FsHA/YSZ powders and the coatings were examined with X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray (SEM/EDX), and the surface roughness, microhardness, corrosion resistance, bioactivity, and in vitro cytotoxicity of the coatings were also determined. The morphological powder analysis revealed particles with a slightly irregular morphology and a fine spherical morphology, while the coating microstructure analysis revealed a fine lamellar morphology, with partially melted and unmelted FsHA particles, and fine microcracks along with evenly dispersed ZrO2 particles. The surface roughness of the FsHA coating increased by 87.5% compared with the uncoated substrate, and the addition of YSZ significantly reduced this value. A 35.5% increase in hardness was obtained in the FsHA + 20 wt.% YSZ coating, and the FsHA coating showed a 43.2% reduction in the corrosion rate compared with the uncoated substrate; a further 73% reduction was observed with the addition of YSZ. The microstructure of the coatings after 14 days of immersion in simulated body fluid (SBF) revealed enlarged cracks and delaminated segments with well-grown apatite spherulite layers on the whole surface of the coatings, while in vitro cytotoxicity analysis showed a good cell viability of 95% at the highest concentration of the specimen.

Non-destructive processing of silver containing glass ceramic antibacterial coating on polymeric surgical mesh surfaces.

Surgical meshes composed of bioinert polymers such as polypropylene are widely used in millions of hernia repair procedures to prevent the recurrence of organ protrusion from the damaged abdominal wall. However, post-operative mesh infection remains a significant complication, elevating hernia recurrence risks from 3.6% to 10%, depending on the procedure type. While attempts have been made to mitigate these infection-related complications by using antibiotic coatings, the rise in antibiotic-resistant bacterial strains threatens their effectiveness. Bioactive glass-ceramics featuring noble metals, notably silver nanoparticles (AgNPs), have recently gained traction for their wide antibacterial properties and biocompatibility. Yet, conventional methods of synthesizing and coating of such materials often require high temperatures, thus making them impractical to be implemented on temperature-sensitive polymeric substrates. To circumvent this challenge, a unique approach has been explored to deposit these functional compounds onto temperature-sensitive polypropylene mesh (PP-M) surfaces. This approach is based on the recent advancements in cold atmospheric plasma (CAP) assisted deposition of SiO2 thin films and laser surface treatment (LST), enabling the selective heating and formation of functional glass-ceramic compounds under atmospheric conditions. A systematic study was conducted to identify optimal LST conditions that resulted in the effective formation of a bioactive glass-ceramic structure without significantly altering the chemical and mechanical properties of the underlying PP-M (less than 1% change compared to the original properties). The developed coating with optimized processing conditions demonstrated high biocompatibility and persistent antibacterial properties (>7 days) against both Gram-positive and Gram-negative bacteria. The developed process is expected to provide a new stepping stone towards depositing a wide range of functional bioceramic coatings onto different implant surfaces, thereby decreasing their risk of infection and associated complications.

Fractal Dimension Analysis of Laser-coated Porous Bioceramic Coatings

In order to solve the problem that the irregular pore structure of the surface of porous bioceramic coating prepared by laser cladding under a certain optimized optimal process parameters is difficult to describe with traditional Euler geometry. In this paper, the pore structure morphology of the bioceramic coating surface was tested by scanning electron microscopy (SEM) creatively, and the SEM image of the coating surface was processed to statistically analysis the pore structure parameters by the picture software Image J, and then the fractal dimension (D_f) of the pore structure was tested by the classic area-perimeter (A-P) method, and the irregular pore structure was successfully systematically described. The research results show that the principle of the method is simple and operable, and the pore structure of the coating in the range of 2.5-10wt.% can be described by the Df value, which is related to the size and the complexity of the pore structure of the bioceramic coating. Corresponding to the pore structure of the 2.5, 5, 7.5 and 10wt.% bioceramic coating respectively, the fractal dimensions is 1.344, 1.352, 1.394 and 1.34, respectively. In which, the D_f value of the 7.5wt.% coating is the highest, it was suggested that pore structure of the coating with 7.5% pore additive addition also has the largest number of pores in the most complex pore structure.

Advances in Multifunctional Bioactive Coatings for Metallic Bone Implants.

To fix the bone in orthopedics, it is almost always necessary to use implants. Metals provide the needed physical and mechanical properties for load-bearing applications. Although widely used as biomedical materials for the replacement of hard tissue, metallic implants still confront challenges, among which the foremost is their low biocompatibility. Some of them also suffer from excessive wear, low corrosion resistance, infections and shielding stress. To address these issues, various coatings have been applied to enhance their in vitro and in vivo performance. When merged with the beneficial properties of various bio-ceramic or polymer coatings remarkable bioactive, osteogenic, antibacterial, or biodegradable composite implants can be created. In this review, bioactive and high-performance coatings for metallic bone implants are systematically reviewed and their biocompatibility is discussed. Updates in coating materials and formulations for metallic implants, as well as their production routes, have been provided. The ways of improving the bioactive coating performance by incorporating bioactive moieties such as growth factors, osteogenic factors, immunomodulatory factors, antibiotics, or other drugs that are locally released in a controlled manner have also been addressed.

Biominerals Added Bioresorbable Calcium Phosphate Loaded Biopolymer Composites

Nanocrystalline calcium phosphate (CP) bioceramic coatings and their combination with biopolymers are innovative types of resorbable coatings for load-bearing implants that can promote the integration of metallic implants into human bodies. The nanocrystalline, amorphous CP particles are an advantageous form of the various calcium phosphate phases since they have a faster dissolution rate than that of crystalline hydroxyapatite. Owing to the biomineral additions (Mg, Zn, Sr) in optimized concentrations, the base CP particles became more similar to the mineral phase in human bones (dCP). The effect of biomineral addition into the CaP phases was thoroughly studied. The results showed that the shape, morphology, and amorphous characteristic slightly changed in the case of biomineral addition in low concentrations. The optimized dCP particles were then incorporated into a chosen polycaprolactone (PCL) biopolymer matrix. Very thin, non-continuous, rough layers were formed on the surface of implant substrates via the spin coating method. The SEM elemental mapping proved the perfect incorporation and distribution of dCP particles into the polymer matrix. The bioresorption rate of thin films was followed by corrosion measurements over a long period of time. The corrosion results indicated a faster dissolution rate for the dCP-PCL composite compared to the dCP and CP powder layers.

Fretting wear properties and microstructure evolution in micro-arc oxidation bioceramic coating pretreated using laser remelting

To improve fretting wear resistance, bio-ceramic coatings were successfully fabricated on TC6 alloy substrates using a combination of laser remelting (LRM) and micro-arc oxidation (MAO). The surface morphology, composition, and residual stress distribution of the coatings were characterized using scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, ultra-deep field three-dimensional microscopy, and X-ray stress analysis. The influence of LRM pretreatment on the fretting wear behaviour of MAO bioceramic coatings was investigated. The LRM pre-treatment did not change the phase composition of the MAO coatings, which were all composed of Al2TiO5, rutile TiO2, and anatase TiO2 phases. However, increasing the content of the rutile TiO2 phase from 68 to 89% improved the uniformity and density of the coatings and decreased the porosity by 2.8%. The fretting wear test results showed that the LRM pretreated MAO coating exhibited the best performance against fretting wear in a simulated body fluid environment. In this case, the fretting wear mechanism was attributed to slight delamination and fatigue wear.

The Influence of rhBMP-7 Associated with Nanometric Hydroxyapatite Coatings Titanium Implant on the Osseointegration: A Pre-Clinical Study.

Background: Bioceramic nanometer coatings have been regarded as potential substitutes for plasma-sprayed hydroxyapatite coatings, and the association with bone morphogenetic protein (BMP) is an attempt to achieve faster osseointegration to hasten oral rehabilitation. Objective: This study aimed to investigate the effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) on the osseointegration of titanium implants coated with a thin film surface of hydroxyapatite (HA). Methods: Two implants (n = 24) were placed in each white New Zealand rabbits’ femur (n = 6). Implants were placed in the right femur after standard instrumentation (A and B) and in the left femur after an over-instrumentation (C and D), preventing bone-implant contact. The distal implants were installed associated with rhBMP-7 (groups B [regular instrumentation] and D [over-instrumentation]) and, also, in the absence of without BMP (control groups A [regular instrumentation] and C [over-instrumentation]). After 4 weeks, the animals were euthanized. The bone blocks containing the implants were embedded in methyl methacrylate and sectioned parallel to the long axis of the implant, which were analyzed by image segmentation. The data were analyzed using a nonparametric statistical method. Results: We observed that Group A had a mean bone formation of 35.6% compared to Group B, which had 48.6% (p > 0.05). Moreover, this group showed 28.3% of connective tissue compared to Group A, with 39.3%. In the over-instrumented groups, rhBMP-7 (Group D) showed an enhanced and significant increase in bone formation when compared with the group without rhBMP-7 (Group C). Conclusion: We concluded that the association of rhBMP-7 to thin nanostructure HA-coated implants promoted greater new bone area than the same implants in the absence of rhBMP-7, mainly in cases of over-instrumented implant sites.

Deposition of Fluoresceine-Doped HAp Coatings via High-Velocity Suspension Flame Spraying

In current medicine, joint revision surgery plays an important role in the treatment of degenerative joint diseases. Infections of the artificial joints are an iatrogenic, accompanying symptom after joint replacement procedures. A new approach is to functionalize the bioactive coatings of the implants by infiltrating them with anti-inflammatory drugs. This work aims at a one-step approach in manufacturing drug-doped, porous hydroxyapatite coatings by high-velocity suspension flame spraying (HVSFS). Thermal exposure of the temperature-sensitive drugs is critical. Therefore, a new process setup, combining one axial and one radial suspension line, is used for coating deposition. The lower dwell time of the suspension in the flame through radial injection helps in controlling the temperature exposition of the contained drug to the flame. Additionally, the influence of the powder morphology, used as a carrier for the drug in the suspension, is investigated by carrying out spray experiments with suspensions from three different granule types. To analyze the temperature exposition within the coating process, fluoresceine was used as a model drug, as the decomposition of the organic, fluorescing molecules can be easily controlled by fluorescence intensity measurements. It could be shown that the deposition of temperature-sensitive organic molecules is possible without degrading the molecular structure by a modified HVSFS process. This knowledge offers new possibilities in the cost-effective one-step manufacturing of functionalized, anti-inflammatory bioceramic coatings on orthopaedic implants.

Evaluation of Corrosion Inhibition of Plasma Sprayed FsHA/YSZ Coating on β-Titanium (Ti-13Nb-13Zr) Alloy Using Electrochemical Techniques

α + β titanium alloys especially Ti-6Al-4V alloy have dominated implant industry over the years due to their high corrosion resistance, strength, and flexibility. However, their high modulus (110GPa) compared to the human bone (18-30GPa) results in aseptic loosening of implants. Hydroxyapatite (HA) coating on Ti-6Al-4V alloys has been used to mitigate these demerits, nevertheless, more still need to be done. Hence, the present study aims at developing a natural and economical bioceramic coating on low modulus Ti-13Nb-13Zr alloy substrates using plasma spraying technique for biomedical applications. The bioceramic used was natural HA derived from fish scales (FsHA) and FsHA doped yttria stabilized zirconia at (10-20 wt.%). FsHA/YSZ powders and the coated samples were examined by XRD and SEM/EDX and the surface roughness, microhardness and corrosion resistance of the uncoated substrate and coated samples determined. The XRD pattern showed good crystalline FsHA/YSZ powders for all the compositions while the microstructure of the coatings revealed a fine splat lamellar morphology with partially melted and non-melted FsHA particles along with evenly dispersed Zr particles within the coating matrix for the FsHA/YSZ coatings. The maximum surface roughness (4.215 µm) was found with the FsHA coating while FsHA/YSZ coatings presented the highest hardness values (492.5-536.9 Hv) compared to the FsHA coating (467.8 Hv) and the uncoated substrate (385.9 Hv). Similarly, the corrosion resistance of the Ti-13Nb-13Zr alloy was significantly improved with the deposition of FsHA/YSZ bioceramic coatings.

Biomechanical and Microtomographic Assessment of the Effectiveness of Osseointegration of Threaded Titanium Implants with Single- and Bilayer Bioceramic Coatings

Biomechanical and Microtomographic Assessment of the Effectiveness of Osseointegration of Threaded Titanium Implants with Single- and Bilayer Bioceramic Coatings

Improved bioceramic coatings reinforced by nanostructured talc

Nano-talc was successfully incorporated in the hydroxyapatite matrix via pulsed electrodeposition after being obtained using an eco-friendly liquid-phase exfoliation process. Scanning electron microscopy, atomic force microscopy, X-ray spectroscopy, Raman spectroscopy, corrosion and wear resistance, and cytocompatibility tests were used to characterize the biocomposite ceramics. Talc significantly improves the nanomechanical and wear properties of bioceramics (i.e., higher stiffness, reduced friction coefficient, and lower wear damage) as well as corrosion resistance. Talc does not induce cytotoxic activity in in vitro cells and may induce bone maturation as per biocompatibility tests.