Introduction: Management of dental caries during early stages is considered a clinical problem in young children. Objectives:The current in-vitro study assessed the influence of four home oral care products on re-mineralization of early caries lesions using enamel micro-hardness (EMH) test and morphological changes with scanning electron microscopy (SEM). Material and methods: Sixty primary canine teeth were selected and randomly divided into 5 groups (n = 12 in each group). Samples were de-mineralized, and toothpaste slurries were prepared to treat de-mineralized enamel with a pH-cycling model. The groups were divided as follows: Group 1. Control (no intervention); Group 2. Fluo ridated toothpaste; Group 3. Tooth mousse containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP); Group 4. Toothpaste containing bio-active glass and fluoride; Group 5. Tooth cream containing nano-hydroxyapatite, fluoride, and xylitol. EMH was evaluated in fifty specimens (each group, n = 10) at three times: before and after de-mineralization, and after 28 days of pH-cycling and treatment. Two samples from each group were observed with SEM. Data were analyzed with multiple-sample repeated measures ANOVA and Tukey's HSD post-hoc tests (p < 0.05). Results: There was a significant difference in EMH between mean baseline values and de-mineralized enamel (p < 0.001). Re-mineralization significantly increased EMH in all treatment groups (p < 0.001). In group 5, the percent of EMH recovery was significantly greater than in other groups (p < 0.001). There were significant differences among the other three treatment groups (all p < 0.001). SEM images showed minerals deposited on the dissolved prismatic enamel in all groups. Conclusions: The nano-hydroxyapatite-based tooth cream was the most effective home oral care product for re-mineralization of primary tooth enamel.