Objectives: Bulk fill base has been generated to help in decreasing the time elapsed in filling posterior teeth with composite resin by conventional layering technique. This review to show the life time of posterior filling teeth by direct composite with and without bulk fill base. Data sources: pubmed, Google Scholar, have been searched for papers that addressed the rule of bulk fill base usage in lifetime of direct posterior composite restoation. It was clear that using bulk fill base under conventional composite in posterior teeth is more prone to failure by increased polymerization shrinkage stresses which lead to tooth fracture and liability for secondary caries neither than conventional layering technique which has more success percentage but showed more liability for composite filling fracture.
