Guiraldo Ricardo Danil, Consani Simonides, Consani Rafael Leonardo Xediek, Berger Sandrine Bittencourt, Mendes Wilson Batista, Sinhoreti Mário Alexandre Coelho, Correr-Sobrinho Lourenço
Department of Restorative Dentistry, School of Dentistry, University of North Paraná, Londrina, PR, Brazil.
Braz Dent J. 2010;21(6):538-42. doi: 10.1590/s0103-64402010000600010.
The aim of this study was to investigate the influence of different composite resins - Filtek P90 (silorane-based composite) and Heliomolar (methacrylate-based composite) - on light transmission and decrease in Knoop hardness between the bottom and top of cured specimens. The irradiance of a light-curing unit (LCU) was measured with a power meter (Ophir Optronics; 900 mw/cm2) and spectral distributions were obtained using a spectrometer (USB 2000). Twenty standardized cylindrical specimens (2 mm thick x 7 mm diameter) of each composite resin were obtained by curing using the LCU for 40 s. Light energy transmission through the composite was calculated (n=10). The Knoop hardness number for each surface was recorded as the mean of 3 indentations. The difference in Knoop hardness between the top and bottom (DKH) of the same specimen was calculated (n=10). The irradiance of light that passed through Filtek P90 (272 mW/cm2) was not significantly greater than that the passed through Heliomolar (271 mW/cm2). The DKH of Filtek P90 (25%) was significantly higher than that of Heliomolar (12%). There was a greater degree of subsurface polymerization of the methacrylate-based composite compared to the silorane-based composite.
本研究的目的是调查不同的复合树脂——Filtek P90（基于硅氧烷的复合材料）和Heliomolar（基于甲基丙烯酸酯的复合材料）——对固化试样底部和顶部之间的透光率以及努氏硬度降低的影响。使用功率计（Ophir Optronics；900 mw/cm²）测量光固化单元（LCU）的辐照度，并使用光谱仪（USB 2000）获得光谱分布。每种复合树脂通过使用LCU固化40秒获得20个标准化圆柱形试样（2毫米厚×7毫米直径）。计算通过复合材料的光能传输（n = 10）。记录每个表面的努氏硬度值作为3次压痕的平均值。计算同一样品顶部和底部之间的努氏硬度差异（DKH）（n = 10）。通过Filtek P90的光辐照度（272 mW/cm²）并不显著高于通过Heliomolar的光辐照度（271 mW/cm²）。Filtek P90的DKH（25%）显著高于Heliomolar的DKH（12%）。与基于硅氧烷的复合材料相比，基于甲基丙烯酸酯的复合材料的表面下聚合程度更高。
