Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 11 1 2014 02 15 56 66 Masumeh Hasani Tabatabaee Associate Professor, Dental Research Center Dentistry Research Institute, Department of Operative Dentistry, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Sakineh Arami Assistant Professor, Department of Operative Dentistry, School of Dentistry Tehran University of Medical Sciences, Tehran, Iran. Maryam Ghavam Associate Professor, Dental Research Center Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Asieh Rezaii Dentist. 2015 10 16 The aim of this study was to assess the effect of bleaching on elution of monomers from nanofilled and microhybrid composites.80 samples (5mm diameter and 3mm thickness) of each composite were prepared. After curing, half of them were randomly polished. Each group was divided into 8 subgroups and immersed in water or 10%, 20% and 30% H2O2 for 3 or 8 hours. Eluted Bis-GMA (Bis-phenol A Glycidyl Dimethacrylate), TEGDMA (Triethyleneglycol Dimethacrylate), UDMA (Urethane Dimethacrylate) and BisEMA (Bis-phenol A ethoxylate Dimethacrylate) were quantified by high performance liquid chromatography and the results were analyzed by univariate ANOVA and t-test (P https://fid.tums.ac.ir/index.php/fid/article/view/558 https://fid.tums.ac.ir/index.php/fid/article/download/558/533