Comparative determination of [Ca 2+ ] in teeth exposed to various beverages

1. Comparative determination of [Ca2+] in teeth exposed to various beverages Travis Slaysman & Joey Orlando

2. Introduction • According to a 2007 edition of General Dentistry, phosphoric acid in soda causes tooth enamel erosion, even with minimal exposure. Dentists use phosphoric acid to scour enamel, obviously it is effective at removing it. • Aside from the obvious health concerns with drinking soda (high fructose corn syrup, sugar & caffeine) • Bovine teeth have been substituted for human teeth in many in vitro dental experiments (Yassen et al 2011) • The main component of teeth is hydroxylapatite, Ca10(PO4)6(OH)2

3. Objectives & Hypothesis • Experimentally determine the calcium loss in bovine teeth after exposure to four separate conditions; Red Bull, Coca-Cola, Sprite, & diH2O • Gravimetric analysis versus volumetric • We hypothesis that the teeth that have been exposed to Red Bull will cause the most calcium deterioration of the teeth, followed by Coca-Cola then Sprite

4. Methods • Standardization of EDTA • pH Measurements • Preparing/massing the bovine teeth samples • Exposure of teeth to beverages • Volumetric Analysis • Gravimetric Analysis

5. Sample Preparation • The teeth we used in our experiment were cow teeth. The teeth were smashed into small enough fragments to place in test tubes containing our soda samples. • The pH of each sample was measured with a calibrated pH meter before the teeth were placed into the each of the solutions. • Each sample was then placed into a test tube with one of our soda samples. The test tubes were then tightly capped to attempt to keep soda samples from degrading as much as possible. The samples then sat, untouched for one week in the test tubes. • After one week, the solid fragments of tooth from each test tube were taken from their test tube, placed in 120 C oven for one day to allow them to dry.

6. Titration Procedures • EDTA was standardized against CaCO3 dissolved in 0.1 M HCl • Standardized EDTA was calculated to be 0.001287 M • Three aliquots (3 mL) were taken from the Red Bull, Sprite and H2O samples and placed into separate Erlenmeyer flasks. • Before titrating these samples, 5 mL of ammonia buffer was added to the solution, as well as three to four drops of calmagite indicator. • 3 mL of the Coca-Cola sample was placed into a 100 mL volumetric flask and diluted to the mark, because Coke is so dark, the calmagite indicator did not allow us to reasonably see an endpoint without dilution. • After dilution, 50 mL of the diluted Coke solution was titrated with EDTA. • In order to titrate the sample of water, our EDTA had to be diluted 50 fold to make it weak enough to gather enough data to determine the calcium content.

7. Gravimetric Analysis • The remaining portions of the solutions were used to then gravimetrically determine the Calcium content of the solutions. • The samples were placed in separate 250 mL Erlenmeyer flasks and placed on individual hot plates with a stir bar. After the samples started to show signs of boiling, a urea solution was added to the samples. • The thermal decomposition of urea is shown below: • (H2N)2CO + 3H2O + heat CO2 + 2NH4+ + 2OH- • When Ca2+ is present in solution with the oxalate ion, the net reaction is: • Ca2+ + C2O42- + H2O  CaC2O4•H2O

8. Gravimetric Analysis (continued) • The solutions were allowed to continue to heat and stir for 30 minutes while calcium oxalate precipitated. • After the solutions were removed from the hot plates, they were immediately vacuum filtered. • After the filtration, the samples were allowed to dry in the 120 C oven for 24 hours.

9. results

10. discussion • Gravimetric & Volumetric methods yielded fairly similar results • Gravimetric – Red Bull was the worst culprit followed by Coke and Sprite • Volumetric – Sprite was the worst followed by Coke and Red Bull • In both methods water yielded a negligible amount of calcium • Inconsistent data exist regarding whether bovine teeth can be considered an appropriate substitute for human teeth in dental research (Yassen et al 2011) • Use a straw – this will decrease the contact of soda with your teeth

11. Conclusions • If you drink one 12 pack of soda per week, after 39.16 years, your teeth will have the same exposure as our samples did.

12. Sources of error • We assumed that because the nutrition labels on the sodas we used said “not a significant source of calcium” that it would not impact our results at all. We aren’t sure of what a “significant source of calcium” would be. • There is a possibility that the sodas could have contained some magnesium which would throw off our results. • The use of bovine teeth instead of human teeth is still not an accepted practice because the although the composition of the teeth is similar, it is not identical. • There is a possibility, due to the fact the teeth were not dried before placed in the soda samples, that the mass lost was skewed because they were dried after they were removed from the soda samples.

13. Further research • Determination of sole [Ca2+] as well as other ion concentrations • Measure calcium deterioration at various intervals • Evaluation of other sodas & energy drinks • Nutritional labels verification to determine whether or not soda is not a significant source of calcium • Obtain human teeth for analysis

14. Literature cited • Yassen, G. H., Platt, J. A., and Hara, A. T. 2011. Journal of Oral Science. Bovine teeth as substitute for human teeth in dental research: a review of literature. 53(3): 273-82.