Aim: This research was designed to evaluate the effect of different types of glass ionomer restorations(GIC) on Surface microhardness and Remineralization of dentin. Materials and methods: Three of (GIC) (medifil, equia fil and zirconomer) were used.A total number of 32 human premolar teeth were used in this study. Standardized two class V cavities, one on the buccal and other on lingual surface of each tooth were prepared.The teeth were sectioned mesio-distally to get (64) then divided into three equal main groups (n=21) according to the restorative materials, group (M): medifil group (E): equia fil group and (Z): zirconomer group. Each group was further subdivided into three equal divisions (n=7) according to the storage times; one day (S1), one month (S2) and three months (S3). The specimens were sectioned longitudinally along to produce two blocks. One part was mounted in epoxy resin for microhardness testing, and the other for energy dispersive x -ray analysis(EDX).Specimens were stored in artificial saliva for one day, one month and three months .A microhardness tester was used to measure the Vickers hardness number (VHN).Results:It was found that the highest mean value of surface micro hardness and remineralization was recorded for medi fil group, while the lowest mean value was recorded for equia fil group. Pair-wise there is no-significant between one month and three month storage. Conclusion: all (GIC) restorations show remineralization to tooth structures also zirconomer over powered by conventional (GIC) because its high fluoride release finally equia fil show increase remineralization with time.