Bacterial adhesion to the surface of biomaterials is an essential step in the pathogenesis of implant-related infections. In this in vitro research, we evaluated the ability of Staphylococcus epidermidis to adhere to the surface of solid biomaterials, including oxidized zirconium-niobium alloy (Oxinium), cobalt-chromium-molybdenum alloy, titanium alloy, commercially pure titanium, and stainless...

The purpose of this pilot investigation was to measure the co-efficient of friction of a cast cobaltchromium alloy specimen and three materials commonly found on the guiding surfaces of the teeth. The static .co-efficients of friction between dental cobalt-chromium alloy (before and after electropolishing) and tooth enamel, composite resin, and dental amalgam alloy were measured using an inclin...

A sensitive spectrophotometric method for the determination of trace amounts of chromium(VI) is described. Chromium(VI) forms chlorochromate anion in the presence of acid and chloride ion. The formed anion is extracted in toluene as ion-pair with a cationic dye rhodamine 6G. At 535 nlll absorption maximum molar absorptivity is 2x104 I mol-I em-I. The colour is stable for 4 h and the system obey...

Internal attack of chromium containing alloys in mixed oxygen-chlorine environments occurs by the formation of pores which penetrate down grain boundaries of the alloys. No internal attack was detected in a binary Fe-20 %Cr alloy at 1200 K in environments containing 2500 ppm C12. The rate of internal attack of alloy 800H in such environments was increased by replacing the O2 in the gas by C02 ....

Particulate wear debris can induce the release of bone-resorbing cytokines from cultured macrophages and fibroblasts in vitro, and these mediators are believed to be the cause of the periprosthetic bone resorption which leads to aseptic loosening in vivo. Much less is known about the effects of particulate debris on the growth and metabolism of osteoblastic cells. We exposed two human osteoblas...

Intergranular stress corrosion cracking (IGSCC) of Alloy 132 weld metal in light water reactor (LWR) structural components is a great concern. The microstructure of Alloy 132 is dendritic and the grain boundaries that are parallel to the direction of the dendrites growth are known to be most susceptible to cracking. In order to correlate the grain boundary microstructure to IGSCC, and in genera...

A 45 yr old male developed pulmonary fibrosis after 29 yrs of employment as a dental technician. He subsequently developed adenocarcinoma of the lung. Diffuse interstitial fibrosis was seen using light microscopy. Neutron activation analysis of non-neoplastic lung tissue demonstrated high levels of chromium and cobalt suggesting the possibility of a chromium-cobalt alloy pneumoconiosis.

Chromium is a naturally occurring, toxic heavy metal used in many industrial processes. The U.S. Department of Labor's Occupational Safety and Health Administration has established specific limits for occupational exposure levels of chromium and guidelines for medical surveillance of individuals who have been exposed to chromium. The author presents a case in which a 54-year-old man who had bee...

Eight retrieved metal-on-metal total hip replacements displayed corrosion damage along the cobalt-chromium alloy liner taper junction with the Ti alloy acetabular shell. Scanning electron microscopy indicated the primary mechanism of corrosion to be grain boundary and associated crevice corrosion, which was likely accelerated through mechanical micromotion and galvanic corrosion resulting from ...

One of the primary reasons for the development of base metal alloys for dental applications has been the escalating cost of gold throughout the 20th century. In addition to providing lower cost alternatives, these nonprecious alloys were also found to provide better mechanical properties and aesthetics for some oral applications. Additionally, certain base metal alloy systems are preferred beca...