Comparison of Biocompatibility of Three Soft Milled Cobalt–Chromium Alloys

2021 ◽  
Vol 21 (7) ◽  
pp. 3950-3954
Author(s):  
Bong Ki Min ◽  
Tae-Yub Kwon ◽  
Min-Ho Hong

In the context of biology and medicine, nanotechnology encompasses the materials, devices, and systems whose structure and function are relevant for small length scales, from nanometers through microns. The purpose of this study was to compare the microstructures and resultant biocompatibility of three commercially available soft milled cobalt–chromium (Co–Cr) alloys (Ceramill Sintron, CS; Sintermetall, SML; and Soft Metal, SM). Disc-shaped specimens were prepared by milling the soft blanks and subsequent post-sintering. The crystal and microstructures of the three different alloys were studied using optical microscopy, X-ray diffractometry (XRD), energy dispersive X-ray spectroscopy, and electron backscatter diffraction. The amounts of Co, Cr, and molybdenum (Mo) ions released from the alloys were evaluated using inductively coupled plasma-mass spectroscopy. The effect of ion release on the viability of L929 mouse fibroblasts was evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The SML alloy showed a finer grain size (approx. 5 μm) and a larger pore size (approx. 5 μm) than the CS and SM alloys, and its XRD pattern exhibited a slightly higher ε phase peak intensity than that of the γ phase. In the CS and SML alloys, the average crystallite sizes of the nano-sized Cr23C6 carbide were 21.6 and 19.3 nm, respectively. The SML alloy showed higher concentrations of Cr and Mo in the grain boundaries than the other two alloys. The SML alloy showed significantly higher Co and Mo ion releases (p < 0.001) and significantly lower cell viability (p < 0.05) than the CS and SM alloys. The combined results of this in vitro study suggest that the three soft milled Co–Cr alloys had different crystal and microstructures and, as a result, different levels of in vitro biocompatibility.

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3402
Author(s):  
Lena Wepner ◽  
Harald Andreas Färber ◽  
Andreas Jaensch ◽  
Anna Weber ◽  
Florian Heuser ◽  
...  

Various orthodontic wire compositions and configurations are present on the market for removable appliances; however, there have still been only few studies focusing on the effect of resin color and additives such as glitter on corrosion of metallic wires under different conditions. Thus, the aim of the study was to compare concentrations of released ions (aluminium, chromium, nickel) in a corrosive medium under three different conditions: non-loaded wires, loaded wires, and non-loaded wires treated with Kukis® cleaning tablets. Six different wires made of three types of steel alloy were embedded in PMMA resin leaving one centimetre of each wire emerging from the resin to come into contact with the corrosive medium. Glitter particles were added to half of the produced test specimens. For the unloaded test series, five specimens of each group were covered in a petri dish with 50 mL of corrosive medium (pH 2.3) following EN-ISO 10271 for seven days at 37 °C. The wires for the mechanically loaded test specimens overlapped the resin by 5 cm and were clamped into a time-switched electric drive for a defined period of time before the samples were taken after a testing time of 7 days. In the third group, unloaded test specimens were transferred from their petri dishes into the prepared Kukis® solution every 24 h before being stored in the corrosive medium. Inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify the specific ions in the corrosive solution. Statistical analysis showed that the mechanical loading of all wires could significantly raise the diffusion of ions into the corrosive medium. The colour of the resin did not affect the concentration of the released ions. The Kukis® cleaning tabs could not lower the corrosion of the tested metals, as some of the wires were corroded even more using the brace cleanser. Glitter-containing test specimens showed significantly higher amounts of aluminium. Mechanical loading as well as the presence of glitter particles in the resin significantly affected ion concentrations.


2011 ◽  
Vol 23 (02) ◽  
pp. 135-140
Author(s):  
Mei-Ju Hou ◽  
Chi-Jen Shih

The main objective of this study is to characterize the in vitro osteo inductive behavior of pearl nano crystallites. The results obtained from X-ray diffraction, Fourier transform infrared (FTIR) spectra, and inductively coupled plasma mass (ICP-MS) analysis demonstrate that the pearls can induce the formation of a hydroxyl apatite (HA) layer on their surface in simulated body fluid (SBF), even after only short soaking periods. Further, MC3T3-E1 cells can easily attach and spread on the pearl powders after 1 h of cultivation.


2021 ◽  
pp. 232020682110157
Author(s):  
Abdolrasoul Rangrazi ◽  
Amirtaher Mirmortazavi ◽  
Reyhaneh Imani ◽  
Davood Nodehi

Aim: The aim of this study was to evaluate the effect of the ozonated water on corrosion of a cobalt–chromium (Co-Cr)-based alloy, which is applied for the fabrication of metal frameworks of removable partial dentures. Materials and Methods: In this in vitro study, a total of 30 disk-shaped samples of a Co-Cr alloy were papered and randomly divided into two groups of 15 specimens. In group 1 (control), the specimens were stored in distilled water (DW), and in group 2, the specimens were stored in ozonated water. Around 90 immersions were performed, and the weight change of each specimen was determined. The ion release was analyzed using an inductively coupled plasma-optical emission spectrophotometer. The potentiodynamic polarization test was performed for each group to assess the corrosion resistance of the Co-Cr alloy. The statistical analysis was performed using SPSS version 22. Data were analyzed by independent samples’ t-test. Results: The results showed no significant difference between the weight changes of the two groups. The test using an inductively coupled plasma-optical emission spectrophotometer demonstrated no significant difference between the groups in Co and Cr ions release. In the potentiodynamic polarization test, both groups present similar corrosion behavior, and ozonated water has no deleterious effect on the corrosion resistance and passive range of the Co-Cr alloy compared to DW. Conclusion: As compared to DW, ozonated water has no significant deleterious effect on the corrosion resistance of the Co-Cr frameworks and can be used for cleaning the removable partial dentures.


2015 ◽  
Vol 1765 ◽  
pp. 71-76
Author(s):  
Ma.G. Joaquín-Morales ◽  
G. Vargas-Gutiérrez ◽  
J.L. Rodríguez-Galicia ◽  
G.I. Vazquez-Carbajal ◽  
J. López-Cuevas

ABSTRACTIn this work, we studied the dissolution of three different refractory compositions belonging to the ternary system SiO2-CaO-MgO into two Simulated Lung Fluids (SLF). The initial powder mixtures were uniaxially pressed and then sintered at 1300-1400 °C. The sintered samples were immersed for times from 1 to 21 days into a given SLF at 37 °C. The samples were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The dissolution of Ca2+, Mg2+ and Si4+ into the SLF was quantified by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). The in vitro studies suggested that all the considered materials had a potential to show a diminished biopersistence in vivo, due to reasons that depended on their chemical and phase composition.


2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Dalia Y. Zaki ◽  
Esmat M. A. Hamzawy

In vitro bioactivity of stoichiometric nepheline-fluorapatite glass/polymethyl-methacrylate (PMMA (C5O2H8)n) composite was evaluated. Four glasses of nepheline/fluorapatite with different ratios (75/25, 80/20, 85/15, and 90/10 mole%) were added in 20 and 40  wt.% to PMMA. The composite samples were soaked in simulated body fluid (SBF) for 25 days. A scanning electron microscope with energy dispersive X-ray microanalysis (SEM/EDX) and thin film X-ray diffraction analysis was used to evaluate the composite materials after immersion in SBF. Inductively coupled plasma (ICP) and pH changes were used in the determination of the ions released and the alkalinity, respectively, after the immersion in Tris-buffered solution. Effect of glass filler loading on compressive strength of the cements was also evaluated. The four binary nepheline-fluorapatite glasses/PMMA cements composites are good potential bioactive materials. The compressive strength was between 70.36 ± 6.47 and 97.30 ± 3.90 MPa. In general, decreases of the compressive strength follow the increase of the glass ratio (i.e., 40 wt.%), but all meet that specified by the ASTM F-451.


2011 ◽  
Vol 493-494 ◽  
pp. 68-73 ◽  
Author(s):  
M. Erol ◽  
A. Özyuğuran ◽  
Ö. Özarpat ◽  
S. Küçükbayrak

In this study, it was aimed to produce bioactive glasses (SiO2-CaO-P2O5-Na2O-SrO) with the substitution of strontium in different weight percentages. Physical, thermal, and in vitro biological properties of the glasses were studied and compared to each other. In vitro simulated body fluid studies were performed to investigate the bioactivity of the produced glass samples. Scanning electron microscopy, X-ray diffraction, ultraviolet spectroscopy and inductively coupled plasma techniques were used to monitor changes in the glass surface and SBF composition. The results showed that all glasses favored precipitation of calcium phosphate layer when they were soaked in SBF; however bioactivity of the glasses increased with the increase of strontium content in the glasses.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
L. T. Bang ◽  
B. D. Long ◽  
R. Othman

The present study investigates the chemical composition, solubility, and physical and mechanical properties of carbonate hydroxyapatite (CO3Ap) and silicon-substituted carbonate hydroxyapatite (Si-CO3Ap) which have been prepared by a simple precipitation method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF) spectroscopy, and inductively coupled plasma (ICP) techniques were used to characterize the formation of CO3Ap and Si-CO3Ap. The results revealed that the silicate (SiO44-) and carbonate (CO32-) ions competed to occupy the phosphate (PO43-) site and also entered simultaneously into the hydroxyapatite structure. The Si-substituted CO3Ap reduced the powder crystallinity and promoted ion release which resulted in a better solubility compared to that of Si-free CO3Ap. The mean particle size of Si-CO3Ap was much finer than that of CO3Ap. At 750°C heat-treatment temperature, the diametral tensile strengths (DTS) of Si-CO3Ap and CO3Ap were about10.8±0.3and11.8±0.4MPa, respectively.


2020 ◽  
Vol 86 (10) ◽  
pp. 5-9
Author(s):  
D. G. Filatova ◽  
A. A. Arkhipenko ◽  
M. A. Statkus ◽  
V. V. Es’kina ◽  
V. B. Baranovskaya ◽  
...  

An approach to sorptive separation of Se (IV) from solutions on a novel S,N-containing sorbent with subsequent determination of the analyte in the sorbent phase by micro-x-ray fluorescence method is presented. The sorbent copolymethylenesulfide-N-alkyl-methylenamine (CMA) was synthesized using «snake in the cage» procedure and proven to be stable in acid solutions. Conditions for quantitative extraction of Se (IV) were determined: sorption in 5 M HCl or 0.05 M HNO3 solutions when heated to 60°C, phase contact time being 1 h. The residual selenium content in the solution was determined by inductively coupled plasma mass spectrometry (ICP-MS) using 82Se isotope. The absence of selenium losses is proved and the mechanism of sorption interaction under specified conditions is proposed. The method of micro-x-ray fluorescence analysis (micro-RFA) with mapping revealed a uniform distribution of selenium on the sorbent surface. The possibility of determining selenium in the sorbent phase by micro-RFA is shown. When comparing the obtained results with the results of calculations by the method of fundamental parameters, it is shown the necessity of using standard samples of sorbates to obtain correct results of RFA determination of selenium in the sorbent phase.


Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 133
Author(s):  
Henryk R. Parzentny ◽  
Leokadia Róg

It is supposed that the determination of the content and the mode of occurrence of ecotoxic elements (EE) in feed coal play the most significant role in forecasting distribution of EE in the soil and plants in the vicinity of power stations. Hence, the aim of the work was to analyze the properties of the feed coal, the combustion residues, and the topsoil which are reached by EE together with dust from power stations. The mineral and organic phases, which are the main hosts of EE, were identified by microscopy, X-ray powder diffraction, inductively coupled plasma atomic emission spectrometry, and scanning electron microscope with an energy dispersive X-ray methods. The highest content of elements was observed in the Oi and Oe subhorizons of the topsoil. Their hosts are various types of microspheres and char, emitted by power stations. In the areas of long-term industrial activity, there are also sharp-edged grains of magnetite emitted in the past by zinc, lead, and ironworks. The enrichment of the topsoil with these elements resulted in the increase in the content of EE, by between 0.2 times for Co; and 41.0 times for Cd in the roots of Scots pine, common oak and undergrowth, especially in the rhizodermis and the primary cortex and, more seldom, in the axle roller and cortex cells.


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