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

Brazilian Dental Journal

Andréia Bolzan De Paula²  Rubens Nisie Tango¹  Mário Alexandre Coelho Sinhoreti¹  Marcelo Corrêa Alves²  Regina M. Puppin-rontani¹ 

[1] ,State University of Campinas Piracicaba Dental School Piracicaba SP ,Brazil

关键词: hardness;    dental materials;    resin cements;    composite resin;   

DOI  :  10.1590/S0103-64402010000200005

来源: SciELO

【 摘 要 】

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 (a=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.

【 授权许可】

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