Aim: To investigate the difference of enamel hardness score on tooth immersed in artificial saliva and cow milk. Materials and methods: The present study was an experimental laboratory with pre- and post-test design. Thirty-two maxillary first premolars were collected and randomly divided into two groups, with 16 samples each immersed in artificial saliva and cow milk. Samples were immersed in an orange flavored soft drink for 5 minutes before exposing to cow milk (group 1) or artificial saliva (group 2) for 5 minutes twice a day until day 3. Enamel hardness score was measured as follows: pretreatment, post demineralization stage and posttreatment at day 1 and day 3 by Micro Vickers hardness tester. Data were analyzed using paired t-test and one way analysis of variance (ANOVA). Results: There was a significant difference (p value = 0.000) on enamel hardness score of group 1 at day 1 (324.39 ± 20.35 VHN) and day 3 (354.80 ± 21.09 VHN) as well as group 2 at day 1 (308.06 ± 15.94 VHN) and day 3 (322.18 ± 16.94 VHN). Tooth enamel hardness on group 1 was significantly different to group 2 both at day 1 (p value = 0.018) and day 3 (p value=0.000). Conclusion: These results suggest that artificial saliva and cow milk can increase the enamel hardness score. However, the efficacy of cow milk to augment the tooth enamel hardness is much higher than that of artificial saliva. Clinical significance: Can be used as a primary advice to the public in as precautionary measures and inhibiting tooth enamel damage from acidic drinks.