Os revestimentos brasileiros na atualidade, face aos requisitos de suas normas ou especificações: a influência de condições higroscópicas de prêsa em suas curvas de expansão térmica [Title in english no available]

Abstract

One of the single, main responsible factors of sucess or insucess of the dental gold cast restoration, with relation to it’s future clinical performance, relies upon the casting investiment. To be reliable, the investiment should possess certain characteristcs, certain minimum requirements established and accepted as specifications. In the present research work, 6 different investments, were investigated: 5 manufactured in Brazil (of which 3 in an exprimental phase) and one manufactured in the United States. It was found that two of the brazilian investments (R4 and R5), most widely used by the dentists in this country, do not comply to the specifications. The investigation of the 3 investments which are in an experimental phase of production, leaves us to believe that in the near future, the dentists in Brasil will have at their disposal, an investment, manufactured in this country, that compiles to the specifications. A modified method is suggested, to verify the dimensional changes that occur in dental casting investments, that is more, in accordance with the continuity of the thecnical procedures followed in the construction of a dental gold cast restorarion.