Purpose: This study designed to evaluate the remineralizing effect of nanofilled glass ionomer combined with titanium dioxide nanoparticle and nano hydroxyapatite in root caries like-lesions. Materials and Methods: sixty specimens from sound human premolars, standardized rounded class V cavities were prepared in the middle of cervical one third of the labial surface of root. Then the specimens were divided into three main groups according to the experimental restored material (20 specimens each). Group (A): received nanofilled glass ionomer (NGI), group (B): received 10% nano hydroxyapatite (NHA) incorporated into conventional glass ionomer (GI), and group (C): received 10% titanium dioxide nanoparticles (TiO2NPs) incorporated in conventional glass Ionomer (GI). Each group was further subdivided into two subgroups of (10 each), according to the topical application of nano hydroxyapatite solution either the surface was treated with 10% nano hydroxyapatite solution (I), or the surface was not treated (II). EDAX measurements were done for all specimens before demineralization, after demineralization, and after remineralization. Results: all materials caused significance remineralization of dentin. When comparing the materials effect on remineralization, (NHA) and (NGI) had much higher phosphors and calcium % change than (TiO2 NPs) when used without (NHA) coat. In comparing use of coat of NHA solution, results showed no significant effects in remineralization, except with TiO2 NPs. Conclusion: Modification of conventional GI restorations using nanoparticles is beneficial to dentin remineralization. NHA topical coat has limited beneficial effect when used in conjunction with NHA and NGI restoration. TiO2 NPs although produces remineralization, is of lesser value than NHA.