Resistencia flexural de ligas do sistema Co-Cr antes e apos a refusão submetidas ou não a soldagem

AUTOR(ES)
DATA DE PUBLICAÇÃO

1993

RESUMO

The purpose of this investigation was to determine the flexural strength of Dentorium, Duracrom and Steeldent, commercially available Co-Cr based alloys, subdued or not to soldering procedure, using only new alloy or a mixture of new and previously casted alloy. Twenty dumb-shaped specimens were manufactured for each one of the alloys, divided into four groups as the following rule: new alloy without soldering procedure; new alloy/casted alloy combination without soldering procedure; new alloy with soldering procedure; and, new alloy/casted alloy combination with soldering procedure. The specimens were cast with carbon voltaic arc as the electric heat source and for the soldering procedure, it was used high-temperature Co-Cr solder alloy, melted with the reducing flame of a oxyacetilene torch as the heat source, while the gap distance was maintained at 0.4 mm. To evaluate the flexural strength, the specimens were submited to perpendicular compression stress provided by the universal testing machine, with a c:ross-head speed of 200 Kgf/min. After that, the fracture surfaces were observed under scanhing electron microscopy. Related to the results, it was verified that: a) Dentorium and Steeldent alloys, neither as one-half new nor as a half-new/once-used combination, showed no statistically significant differences; b) Duracrom alloy showed reduced flexural strength values when conducted in the as mixed condition; c:) either as new or as mixed, the soldered three alloys displayed reduction of about 1/4 in the flexural strength values, when compared with those obtained with the non soldered ones

ASSUNTO(S)

materiais dentarios protese dentaria

ACESSO AO ARTIGO

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