effect of bulk depth and irradiation time on the surface hardness and degree of cure of bulk-fill composites

ABSTRACT

Statement of Problem: for many years, application of the composite restoration with a thickness less than 2 mm for achieving the minimum polymerization contraction and stress has been accepted as a principle. But through the recent development in dental material a group of resin based composites [RBCs] called Bulk Fill is introduced whose producers claim the possibility of achieving a good restoration in bulks with depths of 4 or even 5 mm