Objectives: this study evaluated the effect of casein phosphopeptide-amorphouscalcium phosphate (CPP-ACP) either applied combined with or under glassionomer on shear bond strength of nano ionomers, highly viscous glass ionomerand resin modified glass ionomer restoratives to dentine.Materials and methods: 90 sound human premolars were divided into threegroups: 30 teeth each, according to treatment protocol either without application ofcasein phosphopeptide-amorphous calcium phosphate (CPP-ACP) (as a controlgroup), CPP-ACP applied before application of glass ionomer and CPP-ACPcombined with the glass ionomer. Each group was subdivided into threesubgroups, 10 teeth each, according to type of glass ionomer either nano ionomer,highly viscous glass ionomer or resin modified glass ionomer was used.Results: when CPP-ACP was applied before glass ionomer; Ketac N100 showedthe highest statistical mean shear bond strength followed by Vitremer whichproduced an insignificant effect with other types followed by Ketac MolarEasymix which produced the lowest shear bond strength values. When mixed withglass ionomer No significant interaction between different tested glass ionomertypes.Conclusion: CPP-ACP weather applied before or combined with the differentglass ionomers has no effect on the shear bond strength to dentine.