Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 9 3 2012 09 15 255 61 Mr Rouhollahi Assistant Professor, Department of Operative Dentistry, Faculty of Dentistry, Shahed University, Tehran, Iran. M Mohammadibasir Sh Talim 2015 10 16 Depth of cure of composite material is restricted and it depends on many parameters such as thickness. The aim of this in-vitro study was to evaluate the depth of cure of two light-cured core build-up composites (Quixfil and Photocore) in different thicknesses, when cured for 60 seconds.The Vickers microhardness measurements were made for each side of the top irradiated surfaces of 1,2,3,4,5,6,7 and 8-mm-thick cylindrical blocks of two core build-up light-cured composites (Quixfil and Photocore) and a micro hybrid composite (Z250) as the control group. For each thickness a bottom to top Vickers Hardness Number (VHN) ratio was determined and a value of at least 80% was used to indicate the acceptable depth of curing. The results were analyzed with two way ANOVA and Tukey HSD test. P value https://fid.tums.ac.ir/index.php/fid/article/view/747 https://fid.tums.ac.ir/index.php/fid/article/download/747/722