Aim: The aim of this study was to evaluate and compare the effect of three different remineralizing agents (GC tooth mousse, SHY-NM & Biorepair) on shear bond strength of vitremer resin modified glass ionomer cement to dentine and to determine the mode of failure. Materials and Method: In this study, 20 sound freshly extracted premolars were used. They were divided into four groups, five each, Group I (control group), Five teeth (Mesial and Distal surfaces) were restored with resin modified glass ionomer (Vitremer) without using any remineralizing agents. In group II: Teeth were treated with GC Tooth Mousse then restored with Vitremer. Group III: Teeth (ten surfaces) were treated with SHY-NM then restored with Vitremer. Group IV: Teeth were treated BioRepair Plus then restored with Vitremer. Instron Universal testing machine was used to assess the shear bond strength. Light microscopy (x20 magnification) was used to determine the modes of failure. Results: The highest shear bond strength was in group III after the application of novamine containing paste “Shy-NM”. While the lowest shear bond strength was found in Group I (Control group). For Groups II and IV, the application of both GC tooth mousse and biorepaire increased the shear bond strength of glass ionomer after their application with no significant differences between them. The most frequent failure mode was adhesive (at interface). Adhesive failure was found in 27 samples while the remaining 13 samples were mixed. Conclusion: The shear bond strength of vitremer resin modified glass ionomer to dentine was improved when dentine was pre-treated with 5 % Novamin containing toothpaste, CPP-ACP containing paste, Toothpaste made of hydroxyapatite nanocrystals.