Background:Osteoporosis is a worldwide health problem with serious impact on the human population, particularly the post-menopausal Background:  Prevention of initial dental caries has an essential role instead of the treatment especially in children. Aim: to evaluate the effect of nano-bioactive glass paste, CPP-ACP paste and fluoride varnish on the artificially induced carious lesion of the primary teeth enamel regarding surface microhardness and surface roughness. Materials and methods: sixty extracted primary second molars were divided into four groups (n=15) as follow; group A (Bioactive glass paste), group B (CPP-ACP paste- GC tooth mousse), group C (fluoride varnish- Fluor Protector), group D (control group). The surface microhardness (Vickers Microhardness machine) and surface roughness (Stylus Profilometer) were measured for the control group D as a baseline and for the other three groups after demineralization. After that, different remineralizing agents for 10 days were applied. Then another surface microhardness and roughness tests were done for all groups. The data were collected and statistically analyzed using One Way ANOVA test with Post Hoc Tukey test. Results: Both BAG paste and CPP-ACP paste have a highly significant recovery in compared to fluoride varnish after remineralization in microhardness and SEM evaluation but there was no significant difference between the different study groups in the surface roughness results Conclusion: All of three agents BAG, CPP-ACP and fluoride varnish are capable to remineralize early carious lesions while BAG  is more effective than CPP-ACP but eventually both have similar remineralization potential which is higher than the fluoride.