OBJECTIVE To test the null hypothesis that the aging process in self-ligating brackets is not higher than in conventional brackets. METHODS Twenty-five conventional (GN-3M/Unitek; GE-GAC; VE-Aditek) and 25 self-ligating (SCs-3M/Unitek; INs-GAC; ECs-Aditek) metal brackets from three manufacturers (n = 150) were submitted to aging process in 0.9% NaCl solution at a constant temperature of 37 ± ...

Although alloy tin plating has been known and used for many years, this paper will describe the use of a new non-cyanide tin/zinc alloy as a possible replacement coating for cadmium and the use of a tin/nickel alloy as a possible substitute for barrel decorative chromium plating. A review on the corrosion properties of tin, zinc and cadmium compared to tin/zinc alloys and review of the properti...

We used explosive welding with rolling to produce tliermobimetals on the basis of beryllium bronze and alloys of nickel. It gave us possibility to obtain magnetic and 11011magnetic tliermobilnetals possessi~lg high pllysical and mechanical propel-ties.

Dermal exposure to sensitizing metals is a serious occupational and public health problem. The usual approach to dermal exposure assessment is to process samples by chemical methods that use reactants to digest the metal particles and quantify the mass. In the case of dermal exposure assessment, these reactants are not representative of the skin surface film liquids and hence, may overestimate ...

Zinc nickel alloy was deposited from alkaline bath at a PH of 13-14 with the nickel percentage of 5-9% in our prior research. Present study dealt with the research on 10-12% of Nickel at a PH of 12-13 from Zinc – nickel alloy electrolyte and the remaining percentage of Zinc, required for corrosion resistant applications to be used for reliable alternative of cadmium. Hull cell studies was carri...

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...

Gold and chromium alloy fixed partial dentures of the maxillary posterior type have been studied with respect to surface strains using conditions of static loading. The two techniques used were the brittle lacquer' and electronic strain gauge2'3 methods. Brumfield4 presented work on the analysis of partial denture design using the classical beam theory. Bates5 measured dynamic strains on chromi...

This study evaluated the presence of beryllium surface contamination in a U.S. conventional munitions plant as an indicator of possible past beryllium airborne and skin exposure and used these measurements to classify job categories by potential level of exposure. Surface samples were collected from production and nonproduction areas of the plant and at regional industrial reference sites with ...

DNA damage (alkaline filter elution) and sister chromatid exchange (SCE) frequencies were measured in lymphocytes of 39 welders and 39 controls. The welders showed a significantly higher rate of DNA single-strand breakages and significantly elevated SCE values. These results are not in accordance with those of a former study in which only DNA-protein cross-links were measured. The different res...