The influence of various prefiring treatments of the metallic structure on the metal-ceramic bond strength has been shown for a gold-platinum ceramic alloys. Using analytical techniques with a high sensitivity, it has been possible to show that indium accumulates considerably on and below the metallic surface and that a subsequent sand blasting or acid pickling (hot diluted sulfuric acid) brings the indium level down to the initial value of the alloy. Changes in the resulting mean coefficient of thermal expansion have been computed and verified experimentally. They have then been correlated with the mechanical behavior of the tested metal-porcelain bonds. It has thus been shown that a preliminary oxidation in the air, followed by a hot acid pickling, is the best prefiring procedure. The superficial indium concentration is more homogeneous and closer to the initial content and the bond strength thus obtained is among the highest, with the lowest dispersion. This procedure enables to enhance the fiability on the porcelain-baked-to-metal technique and to increase the safety margin of the bond itself.

Dental Alloys↗

PubMed1977

Skills training and self-administered desensitization in the reduction of public speaking anxiety.

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Anxiety↗

PubMed1975

The presence of complement fixing antibodies to Rous sarcoma virus (Schmidt-Ruppin strain) in patients with various forms of neoplasia.

The presence in men of antibodies to Rous sarcoma virus, an oncogenic virus of avian origin, was demonstrated. The highest antibody incidence was found in patients with various forms of cancer (34.4%, as against the value of 12% recorded in blood donors); these patients also showed an increased antibody level - 1/64 titers were detected in 43 out of 7 patients. The possibility of a human infection with animal oncogenic viruses is discussed, without excluding the hypothesis of a paraimmune reaction.

Antibodies, Viral↗

PubMed1975

Studies on the presence of viral antibodies in patients with various forms of malignant neoplasia.

The study of viral antibodies in 6714 sera demonstrated that the level of antibodies to infectious viruses was the same in cancer patients as in controls. However, the patients with various forms of neoplasia showed a considerable percentage and high antibody levels to viruses with oncogenic potential for animals (adenovirus, SV40, Rous virus) or involved in human carcinogenesis (herpes virus).

Adenoviridae↗

PubMed1975