نتایج جستجو برای: cobalt chromium alloys
تعداد نتایج: 93043 فیلتر نتایج به سال:
Metal-on-metal bearings are being increasingly used in young patients. The potential adverse effects of systemic metal ion elevation are the subject of ongoing investigation. The purpose of this study was to investigate whether cobalt and chromium ions cross the placenta of pregnant women with a metal-on-metal hip resurfacing and reach the developing fetus. Whole blood levels were estimated usi...
PEEK-OPTIMA™ (Invibio Ltd, UK) has been considered as an alternative joint arthroplasty bearing material due to its favourable mechanical properties and the biocompatibility of its wear debris. In this study, the potential to use injection moulded PEEK-OPTIMA™ as an alternative to cobalt chrome in the femoral component of a total knee replacement was investigated in terms of its wear performanc...
Abstract Background and Aim: Biocompatibility in some respects depends on the corrosion behavior of dental alloys. The purpose of this study was to investigate the effect of surface passivation of a cobalt chromium alloy on corrosion behavior. Materials and methods: In this experimental study, 20 samples of Flexicast dental alloy were prepared according to ADA97 standard and after casting, t...
The heating parts of thermogravimetry curves performed for cast alloys in air at high temperatures were analysed, after correction from the effects of air buoyancy variation, to characterize the transient oxidation before reaching the targeted temperature for the isothermal stage usually applied thereafter. This was done here for three binary M-30Cr alloys, six ternary M-30Cr-0.4 and 0.8%C allo...
Tribocorrosion in taper junctions of retrieved anatomic shoulder arthroplasty implants was evaluated. A comparison of the tribocorrosion between cobalt-chromium and titanium alloy stems was conducted and the observations were correlated with the individual's clinical data. Adverse effects caused by metal debris and subsequent elevated serum metal ion levels are frequently reported in total hip ...
Two alloys based on cobalt, designed to be reinforced by HfC and containing chromium with content beyond 30 wt.%, were produced casting. They subjected a 46 h–long isothermal exposure at 1200 °C in synthetic air thermogravimetric monitoring of the oxidation progress. In as–cast state, two contain high quantities script–like shaped carbides. Both them demonstrated much better behavior than previ...
Cobalt (Co2+) is required as an essential trace element to a variety of metabolic functions such as the synthesis of vitamin B12 in mammals. It was proven that cobalt passes through the placenta to the fetus. Cobalt possesses toxic effect on embryo. Also, Chromium (Cr3+) as an essential element for both animal and human nutrition has antioxidative capacity. In this study we examined the effects...
This is a longitudinal study of the daily urinary output and the concentrations in whole blood of cobalt and chromium in patients with metal-on-metal resurfacings over a period of four years. Twelve-hour urine collections and whole blood specimens were collected before and periodically after a Birmingham hip resurfacing in 26 patients. All ion analyses were carried out using a high-resolution i...
We measured the levels of cobalt and chromium in the serum in three groups of patients after uncemented porous-coated arthroplasty. Group 1 consisted of 14 consecutive patients undergoing revision for aseptic loosening. Group 2 comprised 14 matched patients in whom the arthroplasty was stable and group 3 was 14 similarly matched patients with arthritis awaiting hip replacement. Specimens were a...
This paper presents the occurrence, properties and origin of chromium, nickel and cobalt in environmental samples soil, water and the atmosphere. Methods of determining the above-mentioned elements and ways of preparing environmental samples for chemical analyses are presented. The content of chromium, nickel and cobalt in the atmosphere, naturally occurring waters, and soil is shown, along wit...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید