Effect of thickness of indirect restoration and distance from the light-curing unit tip on the hardness of a dual-cured resin cement

This study evaluated the Knoop hardness and polymerization depth of a dual-cured resin cement, light-activated at different distances through different thicknesses of composite resin. One bovine incisor was embedded in resin and its buccal surface was flattened. Dentin was covered with PVC film wher...

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Detalles Bibliográficos
Autores: de Paula, Andréia Bolzan, Tango, Rubens Nisie [UNESP], Sinhoreti, Mário Alexandre Coelho, Alves, Marcelo Corrêa, Puppin-Rontani, Regina M.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2010
País:Brasil
Institución:Universidade Estadual Paulista (UNESP)
Repositorio:Repositório Institucional da UNESP
Idioma:inglés
OAI Identifier:oai:repositorio.unesp.br:11449/71823
Acceso en línea:http://dx.doi.org/10.1590/S0103-64402010000200005
http://hdl.handle.net/11449/71823
Access Level:acceso abierto
Palabra clave:Composite resin
Dental materials
Hardness
Resin cements
Filtek Z250
resin
resin cement
tooth cement
analysis of variance
animal
cattle
chemistry
dental bonding
dental equipment
dental surgery
drug effect
enamel
hardness
methodology
nonparametric test
Analysis of Variance
Animals
Cattle
Composite Resins
Curing Lights, Dental
Dental Bonding, Light-Cured
Dental Cements
Dental Enamel
Dental Restoration, Permanent
Resin Cements
Statistics, Nonparametric
Descripción
Sumario:This study evaluated the Knoop hardness and polymerization depth of a dual-cured resin cement, light-activated at different distances through different thicknesses of composite resin. One bovine incisor was embedded in resin and its buccal surface was flattened. Dentin was covered with PVC film where a mold (0.8-mm-thick and 5 mm diameter) was filled with cement and covered with another PVC film. Light curing (40 s) was carried out through resin discs (2, 3, 4 or 5 mm) with a halogen light positioned 0, 1, 2 or 3 mm from the resin surface. After storage, specimens were sectioned for hardness measurements (top, center, and bottom). Data were subjected to split-plot ANOVA and Tukey's test (α=0.05). The increase in resin disc thickness decreased cement hardness. The increase in the distance of the light curing tip decreased hardness at the top region. Specimens showed the lowest hardness values at the bottom, and the highest at the center. Resin cement hardness was influenced by the thickness of the indirect restoration and by the distance between the light-curing unit tip and the resin cement surface.