Effect of Sandblasting on the Long-Term Corrosion Resistance of Ti G4 in Artificial Saliva

Titanium Grade 4 (G4) is the most commonly used material for dental implants due to its excellent biocompatibility and mechanical properties. However, titanium implants require a rough surface that can increase the biomechanical potential of implant–bone contact and affect protein adsorption speed. In this work, the effect of sandblasting of the Ti G4 surface on the long-term corrosion resistance in artificial saliva of pH = 7.4 at 37 °C was studied. The X-ray diffraction (XRD) single-{hkl} sin2ψ method was used to measure the sandblasted Ti residual stress. In vitro corrosion resistance tests were conducted for 21 days using the open circuit potential method, polarization curves, and electrochemical impedance spectroscopy. Using the Kelvin scanning probe, the electron work function was determined. Analysis of the obtained results showed an improvement in the corrosion resistance of the sandblasted Ti G4 compared to Ti with the machine surface. The increase in corrosion resistance was related to the residual compressive stress of 324.7 MPa present in the sandblasted Ti surface. Sandblasting caused plastic deformation of the Ti surface, which resulted in the improvement in mechanical properties, as evidenced by the increase in the hardness of the sandblasted Ti compared to Ti with the machine surface.

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Long-Term Assessment of the In Vitro Corrosion Resistance of Biomimetic ACP Coatings Electrodeposited from an Acetate Bath

Journal of Functional Biomaterials ◽

10.3390/jfb12010012 ◽

2021 ◽

Vol 12 (1) ◽

pp. 12

Author(s):

Patrycja Osak ◽

Joanna Maszybrocka ◽

Julian Kubisztal ◽

Patryk Ratajczak ◽

Bożena Łosiewicz

Keyword(s):

Corrosion Resistance ◽

Calcium Phosphate ◽

Surface Characterization ◽

Open Circuit Potential ◽

Electrochemical Impedance ◽

Artificial Saliva ◽

Pure Titanium ◽

Open Circuit

Calcium phosphate coatings are able to improve the osseointegration process due to their chemical composition, which is similar to that of bone tissues. In this work, to increase the long-term corrosion resistance and to improve the osseointegration process of commercially pure titanium Grade 4 (CpTi G4), biomimetic amorphous calcium phosphate (ACP) coatings were electrodeposited for the first time from an acetate bath with a pH level of 7.0 and a Ca:P ratio of 1.67. ACP coatings were obtained on CpTi G4 substrate subjected to sandblasting and autoclaving using electrochemically assisted deposition at a potential of −3 V relative to the open circuit potential for 30 min at room temperature. SEM, EDS, 2D roughness profiles, amplitude-sensitive eddy current method, and Kelvin scanning probe were used for the surface characterization of the biomaterial under study. In vitro corrosion resistance tests were conducted for 21 days in artificial saliva using open circuit potential, polarization curves, and electrochemical impedance spectroscopy measurements. The passive-transpassive behavior was revealed for the obtained ACP coatings. The long-term corrosion resistance test showed a deterioration of the protective properties for CpTi G4 uncoated and coated with ACP with immersion time. The mechanism and kinetics of the pitting corrosion on the CpTi G4|TiO2|ACP coating system are discussed in detail.

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Electrochemical Determination of the Corrosion Resistance of Ag-Pd Dental Alloys

Revista de Chimie ◽

10.37358/rc.08.9.1956 ◽

2008 ◽

Vol 59 (9) ◽

Author(s):

Daniel Mareci ◽

Igor Cretescu ◽

Neculai Aelenei ◽

Julia Claudia Mirza Rosca

Keyword(s):

Corrosion Resistance ◽

Open Circuit Potential ◽

Electrochemical Impedance ◽

Corrosion Behaviour ◽

Artificial Saliva ◽

Surface Film ◽

Electrochemical Determination ◽

Open Circuit ◽

Electrochemical Characteristics

The electrochemical behavior of a three Ag-Pd alloys used in dental prosthetics construction for crowns and bridges was studied in artificial saliva using the polarization curves and electrochemical impedance spectroscopy (EIS). The corrosion resistance was evaluated by means of the corrosion currents value and by coulometric analysis. The open circuit potential of Ag-Pd are attributed to dealloying followed by surface enrichment with Ag and the possible formation of an insoluble AgCl surface film on the respective alloy surfaces. Our results have shown that these alloys have a somewhat good corrosion resistance in artificial saliva. When increasing the content of Cu, corrosion resistance decreases. The passivation of all samples occurred spontaneously at the open circuit potential. The electrochemical properties of the spontaneously passivated electrodes at the open circuit potential were studied by EIS. The polarization resistance (Rp) and the electrode capacitance (Cdl) were determined. The polarisation resistance of all the samples increases with the immersion time. The polarization resistances are largest and decrease when increasing the content of Cu. Cu reduces the Ag-Pd alloy corrosion resistance. The present study, thought limited, has shown that electrochemical characteristics can be use to identify such alloys. Knowledge of the in vitro corrosion behaviour of these alloys may lead to better understanding of any biologically adverse effects in vitro.

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Effect of Autoclaving Time on Corrosion Resistance of Sandblasted Ti G4 in Artificial Saliva

Materials ◽

10.3390/ma13184154 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4154 ◽

Cited By ~ 1

Author(s):

Bożena Łosiewicz ◽

Patrycja Osak ◽

Joanna Maszybrocka ◽

Julian Kubisztal ◽

Sebastian Stach

Keyword(s):

Corrosion Resistance ◽

Chemical Stability ◽

Electrochemical Impedance ◽

Artificial Saliva ◽

Electron Work Function ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Oxide Layers ◽

Average Grain Size ◽

The Impact

Titanium Grade 4 (Ti G4) is the most commonly used material for dental implants due to its excellent mechanical properties, chemical stability and biocompatibility. A thin, self-passive oxide layer with protective properties to corrosion is formed on its surface. However, the spontaneous TiO2 layer is chemically unstable. In this work, the impact of autoclaving time on corrosion resistance of Ti G4 in artificial saliva solution with pH = 7.4 at 37 °C was studied. Ti G4 was sandblasted with white Al2O3 particles and autoclaved for 30–120 min. SEM, EDS, 2D roughness profiles, confocal laser scanning microscopy, and a Kelvin scanning probe were used for the surface characterization of the Ti G4 under study. In vitro corrosion resistance tests were conducted using open circuit potential, polarization curves, and electrochemical impedance spectroscopy measurements. It was found that Sa parameter, electron work function, and thickness of the oxide layers, determined based on impedance measurements, increased after autoclaving. The capacitive behavior and high corrosion resistance of tested materials were revealed. The improvement in the corrosion resistance after autoclaving was due to the presence of oxide layers with high chemical stability. The optimal Ti G4 surface for dentistry can be obtained by sandblasting with Al2O3 with an average grain size of 53 µm, followed by autoclaving for 90 min.

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Mechanical Properties, Corrosion Resistance and Bioactivity of Oxide Layers Formed by Isothermal Oxidation of Ti-6Al-7Nb Alloy

Coatings ◽

10.3390/coatings11050505 ◽

2021 ◽

Vol 11 (5) ◽

pp. 505

Author(s):

Krzysztof Aniołek ◽

Bożena Łosiewicz ◽

Julian Kubisztal ◽

Patrycja Osak ◽

Agnieszka Stróż ◽

...

Keyword(s):

Mechanical Properties ◽

Corrosion Resistance ◽

Contact Potential Difference ◽

Isothermal Oxidation ◽

Potential Method ◽

Open Circuit ◽

Kelvin Probe ◽

Contact Potential ◽

Oxide Layers

Titanium and its alloys are among the most promising biomaterials for medical applications. In this work, the isothermal oxidation of Ti-6Al-7Nb biomedical alloy towards improving its mechanical properties, corrosion resistance, and bioactivity has been developed. The oxide layers were formed at 600, 700, and 800 °C for 72 h. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), 3D profilometry, and microindentation test, were used to characterize microstructure, surface geometrical structure, and the hardness of the diphase (α + β) Ti-6Al-7Nb alloy after oxidation, respectively. In vitro corrosion resistance tests were carried out in a saline solution at 37 °C using the open-circuit potential method and potentiodynamic measurements. Electronic properties in the air were studied using the Scanning Kelvin Probe (SKP) technique. The bioactivity test was conducted by soaking the alkali- and heat-treated samples in simulated body fluid for 7 days. The presence of apatite was confirmed using SEM/EDS and Fourier Transform Infrared Spectroscopy (FTIR) studies. The thickness of oxide layers formed increased with the temperature growth from 0.25 to 5.48 µm. It was found that with increasing isothermal oxidation temperature, the surface roughness, hardness, corrosion resistance, and contact potential difference increased. The Ti-6Al-7Nb alloy after oxidation revealed the HAp-forming ability in a biological environment.

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Characterization of NiCrMo Dental Restoration Alloy

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.875.373 ◽

2021 ◽

Vol 875 ◽

pp. 373-378

Author(s):

Ali Haider ◽

Omar Farooq Azam ◽

Muhammad Talha ◽

Saleem Akhtar

Keyword(s):

Mechanical Properties ◽

Corrosion Resistance ◽

Dental Materials ◽

Dental Restoration ◽

Restorative Material ◽

Nicr Alloy ◽

In Vitro Biocompatibility ◽

Dental Prostheses ◽

Materials Used

Restorative material is a class of dental materials used for direct filling and fabrication of indirect restoration. NiCr alloy is a restorative material frequently used for dental prostheses due to its properties and economic reasons. In present work beryllium free NiCrMo alloy was developed and studied for dental restoration application. The alloy have unique characteristics of resistance to oxidation and biocompatibility; the requisites for dental prostheses. NiCrMo alloy is found to possess mechanical strength and fabrication properties suitable for dental repairs. In this study the developed alloy was tested for its mechanical properties, biocompatibility and corrosion resistance. An in-vitro biocompatibility study was carried out. No signs of toxicity and no signs of cell growth inhibition, in presence of NiCrMo alloy specimen, were observed. Mechanical properties and corrosion resistance are found in the range that is suitable for dental prostheses and easy fabrication.

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Effects of hydroxyapatite content on mechanical properties and in-vitro corrosion behavior of ZK60/HA composites

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-1110802 ◽

2020 ◽

Vol 111 (8) ◽

pp. 621-631

Author(s):

Jie Teng ◽

Zili Xu ◽

Jinlong Su ◽

Yuan Li

Keyword(s):

Mechanical Properties ◽

Corrosion Resistance ◽

Corrosion Behavior ◽

Electrochemical Measurement ◽

X Ray Diffraction ◽

Corrosion Morphology ◽

Hardness Tests ◽

Zk60 Alloy ◽

Immersion Testing

Abstract In this study, hydroxyapatite-reinforced ZK60 Mg alloybased composites were fabricated via a powder metallurgy route. The mechanical properties of these composites were studied by compressive tests and hardness tests. The in-vitro corrosion behavior was also investigated using immersion testing and electrochemical measurement. The influence of hydroxyapatite content on the mechanical properties and invitro corrosion behavior was evaluated. The microstructure and corrosion morphology were characterized by means of X-ray diffraction, optical and scanning electron microscopy. The results showed that the composite materials with 10 wt.% hydroxyapatite exhibited a better combination of mechanical strength and corrosion resistance. Compared with ZK60 alloy, the addition of 10 wt.% hydroxyapatite resulted in an increase in corrosion resistance by 38.6%.

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Evaluation of cytotoxicity and corrosion resistance of orthodontic mini-implants

Dental Press Journal of Orthodontics ◽

10.1590/2177-6709.21.5.039-046.oar ◽

2016 ◽

Vol 21 (5) ◽

pp. 39-46 ◽

Cited By ~ 3

Author(s):

Celha Borges Costa Alves ◽

◽

Márcio Nunes Segurado ◽

Miriam Cristina Leandro Dorta ◽

Fátima Ribeiro Dias ◽

...

Keyword(s):

Corrosion Resistance ◽

Statistical Analysis ◽

Atomic Absorption ◽

Artificial Saliva ◽

Atomic Absorption Spectrophotometry ◽

Sem Images ◽

Absorption Spectrophotometry ◽

Mini Implants ◽

Vanadium Ions

ABSTRACT Objective: To evaluate and compare in vitro cytotoxicity and corrosion resistance of mini-implants from three different commercial brands used for orthodontic anchorage. Methods: Six mini-implants (Conexão(tm), Neodent(tm) and SIN(tm)) were separately immersed in artificial saliva (pH 6.76) for 30 and 60 days. The cytotoxicity of the corrosion extracts was assessed in L929 cell cultures using the violet crystal and MTT assays, as well as cell morphology under light microscopy. Metal surface characteristics before and after immersion in artificial saliva were assessed by means of scanning electron microscopy (SEM). The samples underwent atomic absorption spectrophotometry to determine the concentrations of aluminum and vanadium ions, constituent elements of the alloy that present potential toxicity. For statistical analysis, one-way ANOVA/Bonferroni tests were used for comparisons among groups with p < 0.05 considered significant. Statistical analysis was carried out with Graph Pad PRISM software Version 4.0. Results: No changes in cell viability or morphology were observed. Mini-implants SEM images revealed smooth surfaces with no obvious traces of corrosion. The extracts assessed by means of atomic absorption spectrophotometry presented concentrations of aluminum and vanadium ions below 1.0 µg/mL and 0.5 µg/mL, respectively. Conclusion: Orthodontic mini-implants manufactured by Conexão(tm), Neodent(tm) and SIN(tm) present high corrosion resistance and are not cytotoxic.

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Extended Long-Term Culture of MSC-Laden Agarose Constructs Does Not Produce Functional Tissue Comparable to Primary Chondrocytes

ASME 2010 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2010-19643 ◽

2010 ◽

Cited By ~ 1

Author(s):

Alice H. Huang ◽

Robert L. Mauck

Keyword(s):

Mechanical Properties ◽

3D Culture ◽

Biochemical Properties ◽

Clinical Use ◽

Promising Alternative ◽

Chondrogenic Medium ◽

Primary Chondrocytes ◽

The Poor

Articular cartilage lines the surfaces of joints and transmits the forces arising from locomotion. The poor ability of cartilage to self-repair has motivated efforts to engineer replacements that recapitulate this load-bearing function. While chondrocyte-laden constructs have been generated with near-native mechanical properties, limitations in chondrocyte availability may preclude their clinical use. Therefore, mesenchymal stem cells (MSCs), which can undergo chondrogenesis in 3D culture, have emerged as a promising alternative [1]. However, although MSCs deposit a cartilaginous matrix, mechanical and biochemical properties are lower than those achieved with chondrocytes [1, 2]. Using microarray analysis, we recently showed that limitations in functional MSC chondrogenesis may stem from incomplete or incorrect molecular induction; molecular differences were observed between donor-matched differentiated chondrocytes and newly differentiated MSCs over 8 weeks of culture [2]. While some genes remained consistently low in MSCs compared to chondrocytes, others gradually increased with time, approaching chondrocyte levels by 8 weeks. As these molecules may underlie the functional disparity between chondrocytes and MSCs, we hypothesized that longer culture durations may improve MSC-seeded construct properties and chondrogenesis. To test this hypothesis, we characterized the evolution of functional properties of MSC- and chondrocyte-seeded constructs over 4 months of in vitro culture in pro-chondrogenic medium.

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Electrochemical Corrosion Resistance of Ni and Co Bonded Near-Nano and Nanostructured Cemented Carbides

Metals ◽

10.3390/met10020224 ◽

2020 ◽

Vol 10 (2) ◽

pp. 224 ◽

Cited By ~ 1

Author(s):

Tamara Aleksandrov Fabijanić ◽

Marin Kurtela ◽

Irbas Škrinjarić ◽

Johannes Pötschke ◽

Markus Mayer

Keyword(s):

Mechanical Properties ◽

Corrosion Resistance ◽

Grain Growth ◽

Electrochemical Impedance ◽

Electrochemical Corrosion ◽

Common Interest ◽

Cemented Carbides ◽

Wear Resistant ◽

Two Samples ◽

Electrochemical Corrosion Resistance

The advantages of nanostructured cemented carbides are a uniform, homogenous microstructure and superior, high uniform mechanical properties, which makes them the best choice for wear-resistant applications. Wear-resistant applications in the chemical and petroleum industry, besides mechanical properties, require corrosion resistance of the parts. Co as a binder is not an optimal solution due to selective dissolution in an acidic environment. Thus, the development of cemented carbides with alternative binders to increase the corrosion resistance but still retaining mechanical properties is of common interest. Starting mixtures with WC powder, grain growth inhibitors GGIs; VC and Cr3C2, and an identical binder amount of 11-wt.% were prepared. GGIs were added to retain the size of the starting WC powder in the sintered samples. The parameters of the powder metallurgy process were adapted, and samples have been successfully consolidated. A very fine homogeneous microstructure with relatively uniform grain-size distribution and without microstructural defects in the form of carbide agglomerates and abnormal grain growth was achieved for both Ni-bonded and Co-bonded samples. Achieved mechanical properties, Vickers hardness, and Palmqvist toughness, of Ni-bonded near-nanostructured cemented carbides are slightly lower but still comparable to Co-bonded nanostructured cemented carbides. Two samples of each grade were researched by different electrochemical direct current corrosion techniques. The open circuit potential Ecorr, the linear polarisation resistance (LPR), the Tafel extrapolation method, and the electrochemical impedance spectroscopy (EIS) at room temperature in the solution of 3.5% NaCl. From the carried research, it was found that chemical composition of the binder significantly influenced the electrochemical corrosion resistance. Better corrosion resistance was observed for Ni-bonded samples compared to Co-bonded samples. The corrosion rate of Ni-bonded cemented carbides is approximately four times lower compared to Co-bonded cemented carbides.

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