In-vitro Erosion of Bovine Enamel after Exposure to Different Drinks

Methods: 100 enamel specimens (5mm diameter) were gathered from freshly extracted bovine incisors and ground down to a thickness of 1mm. Specimens were randomly attributed to 10 groups (n=10 each). Before starting the experiment all specimens were weighted using a precision balance. Thereafter, they were placed in a pvc pannier which was suspended in a plastic container containing 200 ml of the following fluids: Cola, Cola light, Sprite, apple juice, Red Bull, orange juice, Bonaqua Fruits (Mango-Acai), tap water, chlorine water, and lemon juice. Fluids were continuously ventilated and stored at 37° C for 7 days. Thereafter the specimens were removed from the fluids, rinsed with saline solution for 30 seconds and dried on blotting-paper at room temperature for one hour. Subsequently they where weighted again and the mass loss was calculated in mg. Since Kolmogorov Smirnov test showed normal distribution, means and standard deviations were calculated. One way ANOVA with Bonferroni post hoc test was used to compare the results between groups. 

Results: The mean mass losses were: Cola 7.5mg (0.6); Cola light 5.2mg (0.8), Sprite 26.1mg (7.1), apple juice 27.1mg (6.1), Red Bull 16.6mg (2.9), orange juice 24.3mg (4.9), Bonaqua Fruits (Mango-Acai) 17.8mg (1.7), tap water -0.2mg (0.3), chlorine water -0.3mg (0.3), and lemon juice 32.0mg (5.7). From all drinks, Cola and Cola light showed the least erosivity (p<0.001) whereas lemon juice showed statistically significant higher erosivity than all other drinks except Sprite and apple juice (p<0.01).

Conclusion: Erosivity of common non alcoholic drinks as measured in vitro by substance loss of bovine enamel is varying widely. For example Sprite, apple juice, and orange juice are about five times more erosive than Cola light.