The Effect of Different Milk Products on Enamel Hardness: An In Vitro Study

Objectives: An in vitro study to assess the effect of different milk products on the hardness of enamel surfaces. Materials and Methods: Extracted primary and permanent teeth incisors (15 deciduous and 15 permanent) were collected and cleaned. The extracted teeth were then divided randomly into five groups (n=6 per group): G1- distilled water (control); G2- fresh milk (cow milk); G3- chocolate flavoured milk; G4- orange flavoured cultured milk; G5 - fruit lassi milk. The 10 days immersion cycles for the test products were performed thrice daily and were interspersed with exposure of the artificial saliva. Measurement of microhardness on the enamel surface microhardness measurement were performed at baseline, 5- and 10- day of experimentation using Vickers hardness test machine. The pH of each milk products was also assessed. The data were evaluated with repeated measures ANOVA test. Results: Group 4 had significant reduction in microhardness (p<0.05) compared to the control group while Group 1 showed significant reduction (p<0.05) in microhardness compared to all tested samples for day 5 and day 10. While for intergroup comparison, there was no difference in group 3 and group 2. However, there were significant difference between group 4 and group 5 with all other groups on day 10 (p<0.05). Conclusion: Fresh milk showed to be more effective in increasing the enamel microhardness meanwhile orange culture milk has the highest reduction of enamel surface hardness. Thus, we suggest that milk product with low pH has high tendency in enamel erosion.