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...

The long-term effects of orthodontic appliances in the oral environment and the subsequent leaching of metals are relatively unknown. A method for determining the effects of various types of soldering and welding, both of which in turn could lead to leaching of metal ions, on the growth of osteoblasts, fibroblasts, and oral keratinocytes in vitro, is proposed. The effects of cell behaviour of m...

Background. Metals are very frequent sensitizers causing contact allergy and allergic contact dermatitis worldwide; up-to-date data based on patch test results has proved useful for the identification of a problem. Objectives. In this retrospective study prevalence of contact allergy to metals (nickel, chromium, palladium, gold, cobalt, and titanium) in Lithuania is analysed. Patients/Methods. ...

Degenerative histopathalogical alterations were seen in liver due to chronic exposure of the fish, Labeo rohita to chlorides of chromium, nickel and zinc for 30 days. However, more severe degenerative changes were observed in case of zinc chloride exposed fish than nickel chloride and chromium chloride treated fishes, indicating more toxic nature of zinc chloride. There were enlarged nuclei, co...

Abstract Self-passivating, so-called smart alloys are under development for a future fusion power plant. These containing tungsten, chromium and yttrium must possess an acceptable plasma performance during regular operation of plant demonstrate the suppression non-desirable oxidation tungsten in case accident. The up-scaling bulk to reactor-relevant sizes has begun first samples with diameter 5...

It is shown that, in high-rate pulsed galvanostatic anodic dissolution of type CSN17335 and AISI 304 chromium–nickel steels electrolytes for electrochemical machining (ECM) (chloride, nitrate, mixed chloride–nitrate solutions with a conductivity 0.15 S/cm) using microsecond pulses duration 20–2000 ?s current densities the range 1–100 A/cm2, substantial fraction charge (up to ~40%) spent on form...

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...