This study was performed to evaluate the effect of CPP-ACP-F remineralizing surface treatment and its application time on the durability of the micro-shear bond strength of resin composite restorative material to demineralized dentin using a self-etch adhesive. A total of ninety freshly extracted sound premolars were used. pH cycling was carried out for 14 days to produce an artificially affected dentin. The demineralized teeth were randomly divided into two main groups according to dentin pretreatment with CPP-ACP-F remineralizing agent. A total of 30 teeth were used with no surface pretreatment and were considered as the control group. The remaining 60 teeth were randomly subdivided into two subgroups ( 30 teeth each) according to the time of remineralizing agent (CPP-ACP-F) application (1min and 3 min), and were considered as the pretreated groups. The control and the pretreated groups were further subdivided into two subgroups (15 teeth each) according to aging time (24 hours and3 months). A nano filled resin composite was used (Filtek Z350 universal resin composite) with one type of self-etch adhesive system (Scotchbond universal adhesive). For the micro-shear bond strength test, each tooth was mounted in a readymade mold filled with cold cure acrylic resin, and translucent micro-catheters with an internal diameter of 0.9 mm were utilized for composite packing on the dentin surface. The microtubules were placed on the dentin surface such that two microtubules were made on each premolar.