Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) is ananticariogenic agent. The aim of this study was to evaluate the effect ofremineralized enamel using (CPP-ACFP) or (CPP-ACP) agents on themicroshear bond strength of three single-step self-etch adhesive systems.Methods: forty sound human third molars were divided into four maingroups according to the enamel condition; bonding to ground enamel;demineralized enamel; remineralized enamel with CPP-ACP or CPPACFP.Lingual enamel surface within each main group was sectioned intothree slabs, ending up with a total of 30 slabs per each main group.distributed equally into three subgroups according to the adhesive systemutilized either Clearfil S3 Bond Plus; G-aenial Bond or Single BondUniversal adhesive system. Microshear bond strength was tested. Results:The results demonstrated that there is no difference in the bonding ofsingle-step self-etch adhesive systems to enamel remineralized with (CPPACFP)or (CPP-ACP) agents. However, demineralized enamel is notsuitable for bonding. Also bonding to enamel was weak.