Copper corrosion of dental amalgams in organic and inorganic solutions

Corrosion of copper from Trendalloy and Solila nova high copper dental amalgams in organic acids and inorganic solutions was investigated. The organic solutions were 100 mM lactic or acetic acid. The inorganic solutions used in this study were 100 mM ammonia, 85 mM NaCl and 85 mM NaCl with 10 mM phosphate buffer. Corrosion in distilled water was also measured for control. In addition to soaking of the studied samples in these solutions, other sets of samples were subjected to three treatments together with these solutions; external stress for 30 min at almost equal to 0.7 MPa, heat shock for 10 min at 70[degree sign] C and shaking for 30 min at 60 Hz. Copper concentrations in each solutions were measured using atomic absorption spectrophotometer every month during an eight-month experimental period. Generally, the copper corrosion in the two high copper amalgams was comparable. In lactic and acetic acid solutions, the copper corrosion started at the initial stages with lower rate. Then, the 7[th] and 8[th] months showed a high copper dissolution rate in both solutions. In general, most of the copper in water, ammonia and NaCl were very low or under detection limits. The stress, heat shock and shaking treatments had no effects on their own, but they tend to increase the copper corrosions in combination with the solutions

Effect of acute exposure of microwave radiation on some liver and testicular functions of male albino rats: protective role of propolis and zinc therapy

This present study was conducted to investigate some adverse effects due to microwave exposure as well as investigating the possible effects of acute exposure to radiation on liver and testicular tissues, antioxidant enzymes as superoxide dismutase and toxic free radical lipid peroxide that results from stress oxidative tissue damage as well as the effect of microwaves on some trace elements that act as metalloenzyme as zinc and copper. In this work, four groups of adult male albino rats were used. The first act as a control group, the second group was exposed to microwaves radiation 3 hr/day for seven days consecutively at a dose of 170mw/cm2.sec. and frequency of 2.06 GHz [acute exposure]. The third group was exposed to microwave radiations like the second group in addition to concomitant administration to propolis [10mg/kg b. wt. oral for 7 days] and the fourth group was exposed to microwave radiation like the second group in addition to concomitant administration to oral zinc sulphate [3.14 mg/kg b. wt. oral for 7 days]. After the last exposure, rats were treated with pentobarbital sodium and blood samples were taken by heart puncture for determination of alkaline phosphatase [ALP], alanine aminotransferase [ALT], testosterone and follicle stimulating hormone [FSH]. After blood collection, the animals were decapitated by cervical dislocation, testes and liver were histopathologically observed. Oxidative stress was examined by determination of lipid peroxidation [MDA] and measurement of Cu/Zn ratio