scholarly journals The Effect of N, C, Cr, and Nb Content on Silicon Nitride Coatings for Joint Applications

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1896 ◽  
Author(s):  
Luimar Correa Filho ◽  
Susann Schmidt ◽  
Cecilia Goyenola ◽  
Charlotte Skjöldebrand ◽  
Håkan Engqvist ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Silicon Nitride ◽  
Chemical Stability ◽  
Metal Ion ◽  
Ceramic Coatings ◽  
Future Application ◽  
High Wear Resistance ◽  
Metal Ion Release ◽  
Coating Composition ◽  
Nb Content

Ceramic coatings deposited on orthopedic implants are an alternative to achieve and maintain high wear resistance of the metallic device, and simultaneously allow for a reduction in metal ion release. Silicon nitride based (SiNx) coatings deposited by high power impulse magnetron sputtering (HiPIMS) have shown potential for use in joint replacements, as a result of an improved chemical stability in combination with a good adhesion. This study investigated the effect of N, C, Cr, and Nb content on the tribocorrosive performance of 3.7 to 8.8 µm thick SiNx coatings deposited by HiPIMS onto CoCrMo discs. The coating composition was assessed from X-ray photoelectron spectroscopy and the surface roughness by vertical scanning interferometry. Hardness and Young’s modulus were measured by nanoindentation and coating adhesion was investigated by scratch tests. Multidirectional wear tests against ultrahigh molecular weight polyethylene pins were performed for 2 million cycles in bovine serum solution (25%) at 37 °C, at an estimated contact pressure of 2.1 MPa. Coatings with a relatively low hardness tended to fail earlier in the wear test, due to chemical reactions and eventually dissolution, accelerated by the tribological contact. In fact, while no definite correlation could be observed between coating composition (N: 42.6–55.5 at %, C: 0–25.7 at %, Cr: 0 or 12.8 at %, and Nb: 0–24.5 at %) and wear performance, it was apparent that high-purity and/or -density coatings (i.e., low oxygen content and high nitrogen content) were desirable to prevent coating and/or counter surface wear or failure. Coatings deposited with a higher energy fulfilled the target profile in terms of low surface roughness (Ra < 20 nm), adequate adhesion (Lc2 > 30 N), chemical stability over time in the tribocorrosive environment, as well as low polymer wear, presenting potential for a future application in joint bearings.

11 Understanding the Clinical Performance of Ceramic Coated Femoral Components in Knee Arthroplasty Surgery

2021 ◽  
Vol 108 (Supplement_6) ◽  
Author(s):  
H Khatkar ◽  
M Prokopenko
Keyword(s):  
Knee Arthroplasty ◽  
Metal Ion ◽  
Clinical Performance ◽  
Ceramic Coatings ◽  
Wear Properties ◽  
Ion Release ◽  
Metal Ion Release ◽  
Knee Arthroplasty Surgery ◽  
Arthroplasty Surgery

Abstract Aim In vitro knee simulation has demonstrated favourable wear properties and decreased metal ion release of ceramic coated metal femoral components in total knee arthroplasty surgery. Femoral implants coated with ceramic have been used in patients, however the subsequent clinical performance and time-to-revision of these implants is largely unknown. The scope of this study was to review the current available clinical literature, focusing on retrieval studies of Ceramic-Coated TKAs. Method Literature review of PubMed and MEDLINE. All studies included demonstrated clinical evaluation of implant performance, either in vivo or at revision. Results 9 studies were identified and included for analysis in this study. Retrieval analysis has illustrated microscopic defects in coatings of revised implants, with associated abrasion and 3rd body wear of the polyethylene component. Evidence suggests that coating femoral components with ceramic can prevent effective cement bonding, leading to aseptic loosening and thus earlier implant failure. Despite these problems, high volume centres have been able to demonstrate comparable results when compared with traditional bearing surface combinations. The mechanism behind metal ion hypersensitivity is currently poorly understood; however, the use of ceramic coated knee replacements is demonstrating a reduction in metal ion release. Conclusions Whilst conferring favourable clinical properties in certain instances, the lack of surgical, implant and patient data surrounding the use of this coated implants remains concerning. The literature base remains limited, and meaningful clinical conclusions cannot be drawn. Recommendations include performing robust clinical trials in order to delineate the clinical efficacy of ceramic coatings in knee arthroplasty.

Electrochemically formed passive layers on titanium — Preparation and biocompatibility assessment in Hank's balanced salt solution

2006 ◽  
Vol 84 (9) ◽  
pp. 1132-1145 ◽  
Author(s):  
Baodong Zhao ◽  
Gregory Jerkiewicz
Keyword(s):  
Surface Roughness ◽  
Surface Treatment ◽  
Salt Solution ◽  
Metal Ion ◽  
Prolonged Exposure ◽  
Wide Spectrum ◽  
Open Circuit ◽  
Ion Release ◽  
Experimental Conditions ◽  
Metal Ion Release

Uniform and crack-free passive layers on Ti are prepared using AC voltage in 7.5 wt.% aq. NH4·BF4 at 25 °C. The passive layers possess coloration (wide spectrum of colors) that depends on the experimental conditions. The biocompatibility of such prepared passive layers is evaluated using corrosion science and analytical techniques. Their corrosion behavior, Ti-ion release, surface roughness, and wettability in Hank's Balanced Salt Solution (HBSS) at 37 °C are the main focus of this work. Open-circuit potential and polarization measurements demonstrate that the corrosion potential (Ecorr) of the passive layers becomes more positive than that of the untreated Ti. The value of Ecorr increases as we increase the AC voltage (VAC). Their corrosion rate (CR) is lower than that of the untreated Ti, and they reduced the Ti-ion release level from 230 to 15 ppb. An increase in the AC voltage frequency (f) leads to a slightly higher level of the Ti-ion release (~50 ppb). Surface profilometry, optical microscopy, and scanning electron microscopy (SEM) analyses show that prolonged exposure of the passive layers to HBSS results in changes to their surface topography. The passive layers prepared by the application of AC voltage are rougher and more hydrophilic than the untreated Ti. Our methodology of preparing biocompatible passive layers on Ti might be applied as a new surface treatment procedure for Ti implants.Key words: titanium, metal surface treatment, surface roughness, corrosion, metal ion release, contact angle.

scholarly journals Effect of denture cleansers on metal ion release and surface roughness of denture base materials

2012 ◽  
Vol 23 (4) ◽  
pp. 387-393 ◽  
Author(s):  
Letícia Resende Davi ◽  
Daniela Nair Borges Felipucci ◽  
Raphael Freitas de Souza ◽  
Osvaldo Luiz Bezzon ◽  
Cláudia Helena Lovato-Silva ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Metal Ion ◽  
Pure Titanium ◽  
Acrylic Resin ◽  
Commercially Pure Titanium ◽  
Ion Release ◽  
Nickel Chromium ◽  
Commercially Pure ◽  
Metal Ion Release ◽  
Mechanical Methods

Chemical disinfectants are usually associated with mechanical methods to remove stains and reduce biofilm formation. This study evaluated the effect of disinfectants on release of metal ions and surface roughness of commercially pure titanium, metal alloys, and heat-polymerized acrylic resin, simulating 180 immersion trials. Disk-shaped specimens were fabricated with commercially pure titanium (Tritan), nickel-chromium-molybdenum-titanium (Vi-Star), nickel-chromium (Fit Cast-SB Plus), and nickel-chromium-beryllium (Fit Cast-V) alloys. Each cast disk was invested in the flasks, incorporating the metal disk to the heat-polymerized acrylic resin. The specimens (n=5) were immersed in these solutions: sodium hypochlorite 0.05%, Periogard, Cepacol, Corega Tabs, Medical Interporous, and Polident. Deionized water was used as a control. The quantitative analysis of metal ion release was performed using inductively coupled plasma mass spectrometry (ELAN DRC II). A surface analyzer (Surftest SJ-201P) was used to measure the surface roughness (µm). Data were recorded before and after the immersions and evaluated by two-way ANOVA and Tukey's test (α=0.05). The nickel release proved most significant with the Vi-Star and Fit Cast-V alloys after immersion in Medical Interporous. There was a significant difference in surface roughness of the resin (p=0.011) after immersion. Cepacol caused significantly higher resin roughness. The immersion products had no influence on metal roughness (p=0.388). It could be concluded that the tested alloys can be considered safe for removable denture fabrication, but disinfectant solutions as Cepacol and Medical Interporous tablet for daily denture immersion should be used with caution because it caused greater resin surface roughness and greater ion release, respectively.

scholarly journals Bioactive Plasma Coatings on Orthodontic Brackets: In Vitro Metal Ion Release and Cytotoxicity

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 857
Author(s):  
Lasni Samalka Kumarasinghe ◽  
Neethu Ninan ◽  
Panthihage Ruvini Lakshika Dabare ◽  
Alex Cavallaro ◽  
Esma J. Doğramacı ◽  
...  
Keyword(s):  
Metal Ion ◽  
Prolonged Exposure ◽  
Orthodontic Brackets ◽  
Plasma Polymer ◽  
Functional Coatings ◽  
Key Factors ◽  
Ion Release ◽  
Metal Ion Release ◽  
Surface Functionalisation

The metal ion release characteristics and biocompatibility of meta-based materials are key factors that influence their use in orthodontics. Although stainless steel-based alloys have gained much interest and use due to their mechanical properties and cost, they are prone to localised attack after prolonged exposure to the hostile oral environment. Metal ions may induce cellular toxicity at high dosages. To circumvent these issues, orthodontic brackets were coated with a functional nano-thin layer of plasma polymer and further immobilised with enantiomers of tryptophan. Analysis of the physicochemical properties confirmed the presence of functional coatings on the surface of the brackets. The quantification of metal ion release using mass spectrometry proved that plasma functionalisation could minimise metal ion release from orthodontic brackets. Furthermore, the biocompatibility of the brackets has been improved after functionalisation. These findings demonstrate that plasma polymer facilitated surface functionalisation of orthodontic brackets is a promising approach to reducing metal toxicity without impacting their bulk properties.

scholarly journals A New Nanocomposite Packaging Based on LASiS-Generated AgNPs for the Preservation of Apple Juice

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 760
Author(s):  
Maria Chiara Sportelli ◽  
Antonio Ancona ◽  
Annalisa Volpe ◽  
Caterina Gaudiuso ◽  
Valentina Lavicita ◽  
...  
Keyword(s):  
Metal Ion ◽  
Chemical Characterization ◽  
Average Diameter ◽  
Biological Action ◽  
Metal Species ◽  
Ion Release ◽  
Bioactive Materials ◽  
Transmission Electron ◽  
Metal Ion Release ◽  
Bulk Chemical

Designing bioactive materials, with controlled metal ion release, exerting a significant biological action and associated to low toxicity for humans, is nowadays one of the most important challenges for our community. The most looked-for nanoantimicrobials are capable of releasing metal species with defined kinetic profiles, either by slowing down or inhibiting bacterial growth and pathogenic microorganism diffusion. In this study, laser ablation synthesis in solution (LASiS) has been used to produce bioactive Ag-based nanocolloids, in isopropyl alcohol, which can be used as water-insoluble nano-reservoirs in composite materials like poly(3-hydroxybutyrate-co-3-hydroxyvalerate). Infrared spectroscopy was used to evaluate the chemical state of pristine polymer and final composite material, thus providing useful information about synthesis processes, as well as storage and processing conditions. Transmission electron microscopy was exploited to study the morphology of nano-colloids, along with UV-Vis for bulk chemical characterization, highlighting the presence of spheroidal particles with average diameter around 12 nm. Electro-thermal atomic absorption spectroscopy was used to investigate metal ion release from Ag-modified products, showing a maximum release around 60 ppb, which ensures an efficient antimicrobial activity, being much lower than what recommended by health institutions. Analytical spectroscopy results were matched with bioactivity tests carried out on target microorganisms of food spoilage.

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