Analyses of 51 alloys (conventional, 41, and high-copper, 10) currently available in Australia were made. A rapid and precise procedure was developed that relied on wet-way methods for silver and tin while copper, zinc, mercury, indium and low-level constituents, such as lead, cadmium and antimony, were determined by atomic absorption spectroscopy. The conventional alloys, with two minor exceptions, all complied with the compositional requirements of modern standards and little quantitative variations was noted when the range of the major component was compared with the values obtained in two surveys made over thirty years ago. The high-copper contained, among other factors, an average copper concentration about four times that of conventional alloys. Rather surprising were the contents of mercury, indium, and cadmium found in some of the alloys as well as the low-level concentration of lead, and in a few cases antimony. Other elements were not detected by the sensitive technique used. It is justifiable to recommend that the maximum zinc content to be permitted in zinc-free type alloys should not be greater than 0.01%, and this value was subsequently incorporated in the revised Australian standard 2110-1977: Alloy for Dental Amalgam.
Nine fluoride and one non-fluoride toothpaste, all popular brands in Australia, were purchased from retail outlets and the total fluorine derivatives and some other chemical components determined. Periodically, during 50 weeks' continuous storage at 21 "C, 37 "C, and 45 "C, further testing showed variable changes in free ionic fluoride and some gross decreases in soluble fluorine derivative contents; both were related to storage temperature. Some of the toothpastes may not comply with the water soluble fluorine derivative specifications of the Draft Australian Standard for Toothpastes. ' Scholle RH. Will the manufacturer of the best fluoride dentifrice please stand? J Am Dent Assoc 1981;102:958. Anonymous. Dental products feature. Aust J Pharm 198 I ;62:420.' Ericsson Y. The present state of caries prevention by fluorinecontaining dentifrices. In: Muhleman HR, Konig KG, eds.
Twenty-five dental alginate impression powders were obtained locally and analysed for Pb, Zn, Ba, Cd, As, Be, Hg, Sb, and V contents by atomic absorption spectroscopy; also total fluoride was determined by a conventional wet-way procedure. In addition, some lead containing powders were investigated for the lead content of the aerosol and that extractable from the surface of the set material by aqueous solutions. The results are detailed and concern is expressed at a possible hazard to health, mainly by inhalation of these materials.
A study with 2,400 broilers was carried out to compare the effect of the use of mannanoligosaccharides, Saccharomyces cerevisiae cell wall or growth promoter (Olaquindox) in the diet on broiler. Diets were based on corn and soybean meal. A completely randomized experimental design was used, and the obtained data were evaluated by analysis of variance and test of Tukey at a level of 5%. The following parameters were measured: feed intake, daily weight gain, feed conversion ratio, and mortality. It was concluded that the effect of the inclusion of mannanoligosaccharides in the diet on the studied parameters was significantly higher as compared to the inclusion of cell wall or to the control diet, but the effect was not different as compared to the inclusion of growth promoter
Analysis of two single and eight dual product systems showed the former to be calcium hydroxide dispersed in an aqueous gel in methyl ethyl ketone solution of an acrylic polymer and the latter were cements based on the polymerization occurring when mixing salicylate esters with calcium hydroxide. Using water as an extractant under controlled conditions, specimens of the prepared materials produced marked differences in pH values over 24 hours and conductivity over 72 hours; also cumulative extractions over 26 weeks showed substantial variation in the amount of calcium hydroxide and other solubles.
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