Browsing by Author "Topuz, M."

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Effect of Zro2on Morphological and Adhesion Properties of Hydroxyapatite Reinforced Poly- (Lactic) Acid Matrix Hybrid Coatings on Mg Substrates
(MIM RESEARCH GROUP, 2022) Topuz, M.
The study aimed to reduce the high biodegradability of magnesium (Mg) as well as local infections due to the hydrogen gas formation because of pH increasement around biological tissues. Composite coatings of poly- (lactic acid)/hydroxyapatite (PLA/HA) are commonly employed, although their adhesive strength to the metallic substrates are insufficient. In this study, PLA/HA-zirconia (ZrO2) hybrid coatings were successfully coated on Mg surfaces by means of dip-coating method to enhance this insufficient adhesion strength at the coating - Mg substrate interface with desired surface morphology. Scanning electron microscopy (SEM) micrographs were used to examine the surface morphologies of the coatings, both energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analyses to characterize them elementally and phase formation, respectively. Micro-Vickers hardness measurements were taken on coatings and tape tests were carried out following ASTM D3359 standard to reveal the adhesion strengths. The agglomeration size on the coating surfaces decreased as the ZrO2 reinforcement increased, and the Mg surface was entirely sealed with 30 wt% ZrO2 reinforcement, according to the SEM micrographs. The presence of both HA and ZrO2 in the coating was confirmed by XRD analysis, which also demonstrated that it was crystalline. Adhesion strengths were determined 1B, 3B, 4B, and 5B for HA, HA-10%ZrO2, HA-20%ZrO2, and HA-%30 ZrO2 reinforced hybrid coatings, respectively. As a result, it was concluded that hybrid coatings which reinforcements of ZrO2 particles to the PLA/HA composite coatings reduced agglomeration and enhance the coating - substrate adhesion at the interface. © 2022 MIM Research Group. All rights reserved.
Multifunctional Coatings for Biomedical Applications
(CRC Press, 2025) Yigit, O.; Topuz, M.; Dikici, B.
In recent years, there has been a growing interest in the development of multifunctional coatings for biomedical applications. These coatings have the potential to improve the biocompatibility, durability, and functionality of biomedical implant materials. Multifunctional coatings can provide a range of benefits, including enhanced biocompatibility, reduced infection rates, improved mechanical properties, and increased drug delivery capabilities. They can also be tailored to specific applications, such as antimicrobial coatings for implant surfaces or drug-eluting coatings for stents. There are many different types of materials that can be used to create multifunctional coatings, including polymers, ceramics, metals, and composites. The choice of material depends on the specific application and desired properties of the coating. Various techniques can be used to apply multifunctional coatings, including physical and chemical vapor deposition, electrospinning, sol-gel, or spray coating. These techniques can also be combined to create more complex coatings with multiple functions. Overall, the development of multifunctional coatings for biomedical applications is an exciting area of research that has the potential to significantly improve the performance and longevity of biomedical implant materials. © 2025 selection and editorial matter, Ajit Behera, Kuldeep K Saxena, Dipen Kumar Rajak and Shankar Sehgal. All rights reserved.
Preparation and Characterization of Chitosan/Hydroxyapatite Sol-Gel Coating on Ti-6al
(Certex, INCDTP-ICPI, 2016) Gungor Koc, S.; Dikici, B.; Topuz, M.; Yilmazer, H.; Ozdemir, I.; Niinomi, M.; Nakai, M.
A biocomposite coating containing chitosan and hydroxyapatite was developed on Ti-6Al-4V substrate by a sol-gel method in order to obtain a biocompatible and antimicrobial implant surface which can be used to create a smooth transmucosal region for a faster and better wound healing and an increased bioactivity. The coatings characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis and differential thermal analysis (DTG). Scratch test was carried out to evaluate the adhesion between the coated film and the substrates. The critical load at which the coating film was peeled off from the substrate is determined by using the spherical diamond stylus. The results revealed that the coating roughness is approximately 0.23. The critical load for debonding the coating film from the substrate was determined between 6 to 11N. Only a little wear debris was come out from the coating film in the initial stage of a small-applied load. With increasing the load, the coating film became crushed and finally worn away. © 2016 Certex, INCDTP-ICPI.
Production Technique–structure Relationship in Bioceramic-Coated Scaffold Applications
(Elsevier, 2023) Aslan, N.; Topuz, M.; Aksakal, B.; Dikici, B.
It is well known that the surface of metal-based implants is very resistive in aggressive body environments due to the noble oxide layer naturally formed on their surfaces. However, their osseointegration properties are very low. By the way, specific cells attached are desired on the implant surface when the surface of an implant connects with tissue in many circumstances. Thus in parallel with technological developments, biomedical engineering focuses on the growth of new tissue on the implant surface or in the porosities of the implant. The bulk properties of metallic scaffolds, especially Young’s modulus, can be controlled by the porosity ratio of the scaffold but cannot form a bond between the implant and tissue interfaces. Thus the coating of scaffold walls with a bioactive material is required. In this chapter, bioceramic coating techniques of scaffolds, mechanical and corrosion behavior, biocompatibility, and interactions of surface/tissue interface, especially considering the last published reports, were reviewed, in detail. © 2023 Elsevier Ltd. All rights reserved.
Structural Characterization and In-Vitro Corrosion Response of Ha/Tio2 Composite Coatings on Ti-6al
(Asociace koroznich inzenyru z.s.- AKI - Czech Association of Corrosion Engineers, 2017) Topuz, M.; Burak, D.; Güngör Koç, S.; Mitsuo, N.; Masaaki, N.
The metallic implants are used in various medical areas such as screws, plates, pins or others. Titanium alloys are the most popular implant materials for many years due to their higher strength and biocompatibility and excellent corrosion resistance. However, they need a bioactive layer on their surfaces for improve osseointegration with bone surroundings. In this study, the hydroxyapatite/titania (HA/TiO2) bioactive coatings has been syntheses on Ti-6Al-4V substrates by sol-gel method, successfully. The effect of TiO2 reinforcement to the HA structure was evaluated by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and corrosion tests. The electrochemical susceptibilities of the coatings have been determined under in-vitro conditions by potentiodynamic polarization scanning (PDS) technique. The result showed that the coating structure has porous morphology as cauliflower. In addition, the PDS curves of coated and uncoated specimens show a passive behaviour and the coated sample has higher corrosion resistance than uncoated Ti-6Al-4V sample against the Ringer solution. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. All rights reserved.
Synthesis and Characterization of Hydroxyapatite/Tio2 Coatings on the Β-Type Titanium Alloys With Different Sintering Parameters Using Sol-Gel Method
(Maik Nauka/interperiodica/springer, 2018) Dikici, B.; Niinomi, M.; Topuz, M.; Say, Y.; Aksakal, B.; Yilmazer, H.; Nakai, M.
In this study, hydroxyapatite (HA) based composite films were successfully syntheses on the beta-type Ti29Nb13Ta4.6Zr (TNTZ). The solutionized TNTZ substrates coated with HA and HA/Titania (TiO2) bioactive composite coatings by sol-gel method under various sintering parameters related to sintering temperatures and heating ramp rates. Microstructural observations of the coatings revealed that apatite was formed on the substrates. The hardness values of the coatings increase with increasing both the sintering temperature and the TiO2 concentration in the coatings layer. However, it was found that the heating ramp rate of the sintering was not affecting the hardness values so much. Also, the hardness values of the HA/TiO2 composite coatings at all sintering temperatures were higher than only HA coated TNTZ samples due to the existence TiO2 phases in the HA matrix. Results indicating that the doping of HA with TiO2, improve the physical consistency between the coating layer and the substrates and provide a better inter-particle bonding due to the existence TiO2 phases in the HA.
Synthesis of Implantable Ceramic Coatings and Their Properties
(Elsevier, 2023) Topuz, M.; Yigit, O.; Kaseem, M.; Dikici, B.
Nowadays, emphasis on metallic materials, coating materials, and coating technology to improve osseointegration and increase the lifespan of biological fixation prostheses has become a topic of great interest in the field of prosthetic research. Many published studies showed that the bioactivity-coated surfaces increase the implant–tissue compatibility with their similarities to the bone structure. Therefore several coatings are widely used to increase osteoconductivity on implant material surfaces in the biomedical industry. In this section, synthesis techniques, mechanical and corrosion behavior, osseointegration, and esthetic responses of implantable ceramic coatings, especially considering the last published reports, are reviewed in detail. Besides, an answer to the “are the coatings suitable for in vivo conditions?” is investigated. © 2023 Elsevier Ltd. All rights reserved.
Systematic Characterization and Enhanced Corrosion Resistance of Novel Β-Type Ti-30zr Biomedical Alloys With Halloysite Nanotubes (Hnts) and Zirconia (zro2)-Reinforced Polylactic Acid (Pla) Matrix Coatings
(Elsevier Ltd, 2024) Topuz, M.; Dikici, B.; Kasapoglu, A.E.; Zhao, X.; Niinomi, M.
This study investigates synthesis, the in-vitro corrosion resistance and adhesion performance of PLA-based composite coatings reinforced with halloysite nanotubes (HNT) and zirconia (ZrO2) on beta-type Ti-30Zr-5Mo biomedical alloys. The coatings were synthesized using the sol-gel method and characterized for their surface morphology, chemical composition, and electrochemical properties. SEM analysis revealed the presence of micropores and cracks, particularly in HNT and HNT/ZrO2 bilayer coatings. XPS and Raman spectroscopy confirmed the successful integration of HNT and ZrO2 into the PLA matrix. The potentiodynamic polarization scans and electrochemical impedance spectroscopy (EIS) showed enhanced corrosion resistance for coatings containing HNT and ZrO2, with the HNT/ZrO2 bilayer demonstrating the best performance. Contact angle measurements indicated hydrophilic properties, crucial for bioactive surfaces. Overall, the study demonstrates that HNT and ZrO2 reinforcements in PLA coatings significantly improve the corrosion resistance and bioactivity of Ti-30Zr-5Mo alloys, making them promising candidates for biomedical applications. Details are compared and discussed in the text. © 2024 Elsevier Ltd
Two Simple Methods for Surface Modification of Lithium Disilicate Dental Blocks With Hydroxyapatite
(MIM RESEARCH GROUP, 2020) Topuz, M.; Dikici, B.
Crowns are materials that attracting the attention and lithium disilicates among them widely used because of their high bulk mechanical features. Increasing the bioactivity of crowns has generally been a common aspect of all studies. In this study, lithium disilicate dental blocks were coated with bioactive calcium-phosphate components using sol-gel dip-coating methods to increase their surface bioactivity. Two coating methods called as slurry and powder methods were proposed to obtain dense and remarkable layer on the lithium disilicate substrates. The coating layers were characterized by scanning electron microscopy attached with energy dispersive spectroscopy. Coating procedures have successfully accomplished and show enhanced surface properties with terms of calcium/phosphate ratios. Tri-calcium phosphate obtained by the slurry method, which has 1.5 calcium/phosphate ratio, is a favorable structure for bio-absorbable. However, the powder method has approximately 1.67 calcium/phosphate ratio which necessary for hydroxyapatite (HA) structure for higher crystallinity and lower solubility properties. © 2019 MIM Research Group. All rights reserved.