RESUMO
Volumetric polymerization shrinkage of three resin composites (Suprafil, Z100 and Filtek P60) was determined using four light curing methods: method 1: continuous output with conventional intensity light; method 2: continuous output with higher intensity light; method 3: ramp output and method 4: pulse-delay output. Five disc-shaped specimens were prepared from each material for each curing method. Specimen weight was determined with an analytical electronic hydrostatic balance in air and in water before and after curing. Specific gravity values were then determined. Volumetric polymerization shrinkage was calculated using mathematical formulas. Mean volumetric polymerization shrinkage ranged from 1.882 (.015)% to 2.169 (.028)%. ANOVA indicated significant differences among the materials (p<.05). Light curing methods had no effect on volumetric polymerization shrinkage except for Z-100, where method 2 resulted in significantly higher shrinkage than methods 1 and 4. Suprafil shrunk significantly less than the other two materials in all curing methods.
Assuntos
Resinas Compostas/química , Resinas Compostas/efeitos da radiação , Análise de Variância , Equipamentos Odontológicos , Adaptação Marginal Dentária , Análise do Estresse Dentário , Luz , Teste de Materiais , Estrutura Molecular , Transição de Fase , Polímeros/química , Dióxido de Silício/química , Dióxido de Silício/efeitos da radiação , Estatísticas não Paramétricas , Zircônio/química , Zircônio/efeitos da radiaçãoRESUMO
In order to quantify the gamma-2 phase utilizing Kropp's colorimetrical method, at periods of 1 hour, 12 hours, 48 hours and 1 week, five Cu-rich amalgm alloys were studied. Results pointed out a progressive decrease of gamma-2 along these periods, in all cases; this content was always monor to spheroidal particles alloys, increasing to dispersion type and even more to fillings type.
Assuntos
Cobre/química , Amálgama Dentário/química , ColorimetriaAssuntos
Resinas Compostas , Fraturas dos Dentes/terapia , Adulto , Cor , Estética Dentária , Feminino , HumanosAssuntos
Fluoreto de Cálcio , Ligas Dentárias , Animais , Amálgama Dentário , Fenômenos Físicos , Física , RatosRESUMO
Dental amalgam implanted in rat connective tissue is injurious for the first 16 days. At 32 days, the implanted amalgam is tolerated. The increased copper content of Dispersalloy did not evoke a more serious response of the connective tissue than Fine Cut or Spheraloy amalgam.
