Análise da técnica de fundição rápida segundo a adaptação cervical de infra-estrutura de liga à base de Ni-Cr e expansões de presa e térmica de quatro revestimentos / Analysis of accelerated casting technique in accordance with marginal adaptation of Ni-Cr crown and curing expansion and thermal expansion of four investments

AUTOR(ES)

Paulo Fukashi Yamaguti

DATA DE PUBLICAÇÃO

2007

RESUMO

With the improvement of dental investments for accelerated casting technique, recent studies have demonstrated that the procedure can be considered safe for daily use in the dental laboratory. Thus, cast pieces can be obtained in less time, the prosthetic work as a whole can be speed up and costs are cut with no quality compromise. Even though, there are still unanswered questions on how investments expand. It is thought that to reach the best cervical adaptation the greatest investment total expansion is needed, but some studies have demonstrated that other factors can be determining. The aim of this study was to verify the cervical adaptation of nickelchromium crowns cast using four dental investments for the accelerated casting technique and to analyze the curing and thermal expansion of such investments. For each investment, ten samples were obtained. For thermal expansion analysis three samples of each investment were used. For statistical purposes ANOVA and Tukey tests were used. The use of Heat Shock yielded the best results of cervical adaptation, followed by Flash, Bellavest SH and Micro-Fine 1700. For thermal expansion, 15 minutes after investment, none of the investments had reached their complete expansion. After 20 minutes inside the oven all investments had completed their expansion. It was concluded that all investments tested are suitable to offer cast pieces with adequate cervical adaptation. Adaptation depends not only of the greatest total expansion, but also of the curing and thermal expansion. There are indications that investment compression strength plays an important role on the technique.

ASSUNTO(S)

adaptação marginal dental casting technique marginal adaptation técnica de fundição odontológica dental casting investments revestimento para fundição odontológica

Documentos Relacionados

• Influencia de fontes de calor de fundição na fusibilidade e dureza de uma liga de Ni-Cr nova refundida acrescida ou não de liga nova
• Effect of casting atmosphere on the shear bond strength of a ceramic to Ni-Cr and Ni-Cr-Be alloys
• Effect of casting temperature and atmosphere on castability of Ni-Cr alloys: a comparative study with direct flame casting method
• Microdureza de ligas de Ni-Cr fundidas sob diferentes condições
• Desajuste marginal de infra-estrutura de protese fixa obtida pela tecnica de fundição sobre-modelo refratario