Calcium Phosphate Affects Erosivity of non Alcoholic Beverages in Vitro

Method: 90 dentin specimens (5mm diameter, 1mm thickness) from freshly extracted bovine incisors were randomly attributed to 9 groups (n=10 each). Before starting the experiment all specimens were weighted using a precision balance. Thereafter, they were placed in pvc panniers which were suspended in plastic containers containing 150ml of the following beverages: Cola, orange juice, Red Bull, Bonaqua Fruits. To all beverages 100mg (c1) or 200mg (c2) calcium phosphate was added, resulting in 8 groups. Tap water served as control. Fluids were continuously ventilated and stored at 37°C. The specimens were removed from the fluids after 7 days, rinsed and dried, and weighted again. Mass loss was calculated in mg. Since Kolmogorov Smirnov test showed no normal distribution, medians were calculated. Mann-Whitney test with Bonferroni correction was used to compare the mass changes from baseline to results after 7 days between beverages and water.

Result: Median mass losses (min, max; negative values = gains) were: water 1.65mg (1.20;2.40); Cola-c1 0.55mg (0.00;5.50); Cola-c2 -0.65mg (-1.20;0.40); orange juice-c1 12.30mg (7.80;17.30); orange juice-c2 5.30mg (0.50;10.30); Red Bull-c1 10.55mg (7.70;13.50); Red Bull-c2 1.35mg (-5.20;4.10); Bonaqua Fruits-c1 1.20mg (-0.90;1.60); Bonaqua Fruits-c2 0.45mg (-2.00;2.40). Cola-c1 & -c2, and Bonaqua Fruits-c2 & -c2 were significantly less erosive than tap water whereas orange juice-c1 and Red Bull-c1 were still significantly more erosive than water (p<0.05). This significance was not found for orange juice-c2 and Red Bull-c2.

Conclusion: The addition of calcium phosphate may reduce or even prevent the erosivity of highly erosive non alcoholic beverages on bovine dentin. This effect is depending on the concentration of the added calcium phosphate.