Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/80230
Type: Artigo de periódico
Title: Influence of number and position of flasks in the monomer release, Knoop hardness and porosity of a microwave-cured acrylic resin
Author: De Oliveira, VMB
Leon, BLT
Cury, AAD
Consani, S
Abstract: Simultaneous irradiation of multiple flasks may have deleterious effects on the polymerization of microwave cured-acrylic resins. This study evaluated the effect of the number and position of flasks in the monomer release, Knoop hardness and porosity of a microwave-cured acrylic resin. Samples were made of Acron MC(R) (AMC, GC Dent. Ind. Corp.) processed at 500 W. The following associations of the number and position of the flasks were tested: one simple flask centrally placed on the turning plate (I, control); two flasks, one in the centre (IIa) and the other peripherally placed in the plate (IIb); two flasks centrally, one above (IIIa) and the other below (IIIb). The processing time varied according to the number of flasks: 3 or 4.5 min for one or two flasks, respectively. For monomer release, each specimen (n = 12) was put in an assay glass tube containing 6 mL of deionized water that was changed daily. Monomer levels were obtained by spectrophotometry at 206 nm. For hardness test (n = 10), 12 indentations were made in the surface of each specimen. Immersing the polished specimens in permanent ink and counting the porous in a stereo light microscope verified the porosity. Monomer release was significant before 24 h: GI = 263.1(153.3)(a), GIIa = 236.9(180.2)(a), GIIb = 441.5(446.2)(a), GIIIa = 1216.6(857.9)(b). Tukey test showed no statistically significant differences among the groups for porosity and hardness. Monomer release was affected by the position of the flask (P < 0.05).
Subject: microwave acrylic resins
monomer release
hardness
porosity
Country: Inglaterra
Editor: Blackwell Publishing Ltd
Rights: fechado
Date Issue: 2003
Appears in Collections:Unicamp - Artigos e Outros Documentos

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