scholarly journals Formation of a Calcium Phosphate Layer with Immobilized Cobalt Chromite Nanoparticles on Cobalt−Chromium Alloy by a Laser-Assisted Biomimetic Process

2020 ◽  
Vol 10 (16) ◽  
pp. 5584
Author(s):  
Ayako Oyane ◽  
Ikuko Sakamaki ◽  
Kenji Koga ◽  
Maki Nakamura
Keyword(s):  
Calcium Phosphate ◽  
Alloy Layer ◽  
Chromium Alloy ◽  
Cobalt Chromium ◽  
Metallic Biomaterials ◽  
Intermediate Layers ◽  
Transmission Electron ◽  
Cap Layer ◽  
Chromium Oxide Layer ◽  
Dental Applications

The biocompatibility and osteoconductivity of metallic biomaterials can be achieved by calcium phosphate (CaP) coating. We recently developed a laser-assisted biomimetic (LAB) process for rapid and area-specific CaP coating on several materials. In the present study, the LAB process was applied to cobalt–chromium (Co−Cr) alloy, a metallic biomaterial widely used in orthopedic and dental applications. The LAB process was conducted by irradiation of unfocused pulsed laser light onto the substrate immersed in supersaturated CaP solution. The LAB-processed substrate formed CaP on the irradiated surface within only 5 min and was coated with a micron-thick CaP layer within 30 min by the effects of laser-induced surface modification and heating. Ultrastructural analysis with transmission electron microscopy revealed that the resultant CaP layer was integrated with the underlying substrate through two intermediate layers, an upper chromium oxide layer and a lower Co-rich (Cr-deficient) alloy layer. The CaP layer was loaded with a large number of cobalt chromite (CoCr2O4) nanoparticles. The results obtained offer new insights into the mechanism of CaP coating in the LAB process and future applications of LAB-processed Co−Cr alloys.

scholarly journals Delivery of paclitaxel from cobalt–chromium alloy surfaces without polymeric carriers

Biomaterials ◽  
2010 ◽  
Vol 31 (20) ◽  
pp. 5372-5384 ◽  
Author(s):  
Gopinath Mani ◽  
Celia E. Macias ◽  
Marc D. Feldman ◽  
Denes Marton ◽  
Sunho Oh ◽  
...  
Keyword(s):  
Chromium Alloy ◽  
Cobalt Chromium ◽  
Polymeric Carriers ◽  
Cobalt Chromium Alloy

High resolution transmission electron microscopy of age-hardenable Au–Cu–Zn alloys for dental applications

Biomaterials ◽  
2003 ◽  
Vol 24 (12) ◽  
pp. 2061-2066 ◽  
Author(s):  
Hyo-Joung Seol ◽  
Takanobu Shiraishi ◽  
Yasuhiro Tanaka ◽  
Eri Miura ◽  
Kunihiro Hisatsune
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Transmission Electron ◽  
Dental Applications ◽  
Zn Alloys

Abstract 1122‐000142: Safety and Efficacy of Surpass Streamline for Intracranial Aneurysms: A Multicenter US Real‐World Experience (SESSIA)

2021 ◽  
Vol 1 (S1) ◽  
Author(s):  
Juan Vivanco‐Suarez ◽  
Alan Mendez‐Ruiz ◽  
Farooqui Mudassir ◽  
Cynthia B Zevallos ◽  
Milagros Galecio‐Castillo ◽  
...  
Keyword(s):  
Real World ◽  
Intracranial Aneurysms ◽  
The United States ◽  
Chromium Alloy ◽  
Cobalt Chromium ◽  
Anterior Circulation ◽  
Safety And Efficacy ◽  
Post Marketing ◽  
The Mean

Introduction : Flow diversion has established itself as standard treatment of wide complex intracranial aneurysms (IA). Its recognition has been validated with positive occlusion rates and favorable clinical outcomes. The Surpass Streamline (SS) flow diverter (FD) is a braided cobalt/chromium alloy implant with 72 or 96 wires approved by the FDA in 2018. The aim of this study is to determine the safety and efficacy of the SS in a post‐marketing large US cohort. Methods : We performed a multicenter, retrospective study for consecutive patients treated with the SS FD for IA between January 2018 and June 2021 in the United States. Inclusion criteria for participants were: 1. Adults (≥ 18 years) and 2. Treatment with SS FD for IA. Primary safety end point was a major ipsilateral stroke (increase in National Institutes of Health Stroke Scale Score of ≥ 4) or neurological death within 12 months. Primary efficacy was assessed using the 3‐point Raymond‐Roy (RR) occlusion scale on digital subtraction angiography (DSA) at 6‐12‐month follow‐up. Results : A total of 276 patients with 313 aneurysms were enrolled. The median age was 59 years and 199 (72%) were females. The most common comorbidities included hypertension in 156 (57%) subjects followed by hyperlipidemia in 76 (28%) patients. One hundred and twenty‐two (44%) patients were asymptomatic while subarachnoid hemorrhage was present in only 10 (4%) patients. A total of 143 (46%) aneurysms were left‐sided. Aneurysms were located as follows: 274 (88%) were in the anterior circulation with paraophthalmic being the most common in 120 (38%) followed by petrocavernous ICA in 81 (26%); 33 (11%) aneurysms were located in the posterior circulation with basilar trunk being the most common in 14 (5%). The mean maximum aneurysm dome width was 5.77 ± 4.7 mm, neck width 4.22 ± 3.8 mm and dome to neck ratio was 1.63 ± 1.3 mm. The mean number of SS FD implanted per aneurysm was 1.06 (range 1–3) with more than one SS FD implanted in 21 (7%) aneurysms. Modified Rankin Scale (mRS) of 0–2 was present in 206/213 (97%) patients at 6–12 month follow‐up. The complete aneurysm occlusion (RR 1) rate was 145/175 (83%) among subjects who had angiographic follow‐up at 6–12 months. Major stroke and death was encountered in 7 (2%) and 5 (1.8%) of the patients respectively. Conclusions : Our data represent the largest real‐world study using SS FD. These results corroborate its post‐marketing safety and efficacy for the treatment of intracranial aneurysms showing more favorable rates to the initial experience during SCENT trial.

Mechanical strength of laser-welded cobalt-chromium alloy

2004 ◽  
Vol 69B (2) ◽  
pp. 121-124 ◽  
Author(s):  
N. Baba ◽  
I. Watanabe ◽  
J. Liu ◽  
M. Atsuta
Keyword(s):  
Mechanical Strength ◽  
Chromium Alloy ◽  
Cobalt Chromium ◽  
Cobalt Chromium Alloy

scholarly journals Effect of recasting on the elastic modulus of metal-ceramic systems from nickel-chromium and cobalt-chromium alloys

2007 ◽  
Vol 64 (7) ◽  
pp. 469-473 ◽  
Author(s):  
Nemanja Mirkovic
Keyword(s):  
Elastic Modulus ◽  
Testing Machine ◽  
Fracture Load ◽  
Bending Test ◽  
Chromium Alloy ◽  
Cobalt Chromium ◽  
Nickel Chromium ◽  
Ceramic Samples ◽  
Chromium Alloys ◽  
Metal Ceramic

Background/Aim. Elastic modulus of metal-ceramic systems determines their flexural strength and prevents damages on ceramics during mastication. Recycling of basic alloys is often a clinical practice, despite the possible effects on the quality of the future metal-ceramic dentures. This research was done to establish recasting effects of nickel-chromium and cobalt-chromium alloys on the elastic modulus of metalceramic systems in making fixed partial dentures. Methods. The research was performed as an experimental study. Six metal-ceramic samples of nickel-chromium alloy (Wiron 99) and cobalt-chromium alloy (Wirobond C) were made. Alloy residues were recycled through twelve casting generations with the addition of 50% of new alloy on the occasion of every recasting. Three- point bending test was used to determine elastic modulus, recommended by the standard ISO 9693:1999. Fracture load for damaging ceramic layer was recorded on the universal testing machine (Zwick, type 1464), with the speed of 0,05 mm/min. Results. The results of this research revealed significant differences between elasticity modules of metal-ceramic samples in every examined recycle generation. Recasting had negative effect on the elastic modulus of the examined alloys. This research showed the slight linear reduction of elastic modulus up to the 6th generation of recycling. After the 6th recycling there was a sudden fall of elastic modulus. Conclusion. Recasting of nickelchromium and cobalt-chromium alloys is not recommended because of the reduced elastic modulus of these alloys. Instead of reusing previously recasted alloys, the alloy residues should be returned to the manufacturer. .

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