The Effect of Different Beverages on Teeth Over Time

Tyrone Li 11-7-07 82-6

The Effect of Different Beverages on Teeth Over Time

Tyrone Li 11-7-07 82-6 1

TABLE OF CONTENTS

Report SectionI. INTRODUCTION 4

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II. VARIABLES

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III. HYPOTHESIS

4

IV. MATERIALS

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V. PROCEDURE

5

VI. RESULTS

5

VII. CONCLUSIONS

7

BIBLIOGRAPHY

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2 ABSTRACT The purpose of this experiment is to discover which beverage has the darkest stain on eggshells over time. Beverages tested in this experiment were coffee, tea, cola,grape juice, and regular tap water. These eggshells were all placed in each beverage for a predetermined amount of time. Whenever the egg was to be measured it was taken out of the beverage, rinsed gently, and compared with the darkness shade scale. The darkness of the eggshell was recorded in the logbook. After completing the experiment, the beverage that was the darkest and had the most coloring had the darkest stain. Grape juice had a stain that was rated ten while the lowest rating was zero for tap water.

3 I. INTRODUCTION Many people buy different drinks and food from the store. Many of these drinks contain sugar and artificial coloring that could stain teeth. Some of these beverages are grape juice, cola, coffee, and tea. Eggshells are a good substitute for teeth because they are made out of similar material. The objective of this experiment is to find out which beverage stains eggshells the most over time. The experimental variables are coffee, tea, cola, gape juice, and tap water. The dependent variable is the darkness of the stain on the eggshell compared to the stain chart. The eggshell will be soaked in the liquid for a predetermined amount of time, and then its shade will be compared to the Dentist's teeth stain chart. The amount of time that the egg is left in the liquid and the type of eggshell will always be the same for every part of the experiment. The color of teeth is not always the same for everyone. The only ways that people can control

their teeth color is to avoid medication that can cause stains, eat or drink less of different staining drinks or food, to brush their teeth (www.dental-picture-show.com). Eggshells and teeth were found to be similar in material. Eggshells are made out of calcium carbonate while teeth are made out of calcium phosphate(www.madsci.org). A way that different foods or drinks stain teeth are through cracks in the surface of the enamel (Gelb, 148, 112, 123). They reach the second layer of the tooth which is the dentine which absorbs the colors of the food, therefore making the tooth look darker in color. Also, acidic juices and pigmented foods and drinks cause more stains then others that are not (www.stainexpert.co.uk). Acid can also cause teeth to become darker and darker shades of yellow over time while also making the enamel of the tooth very soft, therefore making the tooth very susceptible to many different teeth problems such as cavities (today.ninemsn.com.au). To find different independent variables, the table of contents for each beverage was used to determine what beverage to buy. Some ingredients that were searched for were high amounts of sugar, caffeine, and acid of any kind. If the grape juice is used to soak the egg then the egg will have the darkest stain because it has acid that would make the eggshell more vulnerable to stains. Acid softens enamel which can allow the grape juice to reach the dentine which will then make it permanent (www.stainexpert.co.uk). How different ingredients such as caffeine and acid can affect calcium can be learned from this experiment. How different beverages affect calcium carbonate can also be learned from this experiment. A future experiment can be conducted using different foods instead of beverages. Actual teeth can also be used instead of eggshells. II. VARIABLES Experimental Variable: Coffee, Tea, Cola, Grape Juice, Tap Water Dependent Variable: The darkness of the stain on the egg compared to the stain chart Controlled Variables: Amount of time the egg is left inside the drink, the amount of liquid used for each egg, compared results to the same Dentist's Scale, same container, same type of egg Control Run: Using water as the drink for the egg III. HYPOTHESIS If the grape juice is used to soak the egg then the egg will have the darkest stain 4 because it has acid that would make the eggshell more vulnerable to stains. IV. MATERIALS 1000 ml Coffee 1000 ml Cola Cup 16 White Eggshells Tap Water 1000 ml Tea 1000 ml Grape Juice Dentist's Teeth Stain Chart Timer V. PROCEDURE 1. Pour enough of the drink to cover half of an eggshell into container. 2. Put half of an eggshell into the container. 3. Take eggshell out of liquid after fifteen minutes. 4. Rinse shell and compare it to Dentist's Scale and record results.

5. Place eggshell back into liquid for another forty-five minutes. 6. Rinse and compare eggshell to Dentist's Scale and record results. 7. Place shell back into liquid for an additional one hour. 8. Rinse and compare shell to Dentist's Scale and record results. 9. Place shell back into liquid for another three hours. 10. Rinse and compare to Dentist's Scale and record results. 11. Place shell back into liquid for another six hours. 12. Rinse and compare to Dentist's Scale and record results. 13. Place shell back into liquid for an additional 168 hours 14. Repeat steps number one to thirteen two additional times. 15. Repeat steps number one to fourteen for each beverage. VI: RESULTS Table 1: The Effect of the Beverage on the Stain over TimeTime (hours) Coffee 1 Coffee 2 Coffee 3 Tea 1 Tea 2 0.25 3 2 2 0 0 1 3 3 2 0 1 2 4 4 4 1 1 5 5 5 4 2 2 11 5 5 5 3 3 179 5 6 5 4 4 Tea 3 Cola 1 Cola 2 Cola 3 Grape Juice 1 Grape Juice 2 Grape Juice 3 Water 1 Water 2 Water 3 0 4 3 4 4 3 4 0 0 0 0 4 4 4 5 4 5 0 0 0 0 5 4 5 7 7 8 0 0 0 2 5 5 5 8 8 8 0 0 0 3 5 6 5 9 9 9 0 0 0 4 5 6 5 10 10 10 0 0 0

5 Table 2: The Average Effect of the Beverage on the Stain over TimeTime(Hours) 0.25 1 2 5 11 179 Coffee 2.33 2.67 4 4.67 5 5.33 Tea 0 0.33 0.67 2 3 4 Cola 3.67 4 4.67 5 5.33 5.33 Grape J uice 3.67 4.67 7.33 8 9 10 Water 0 0 0 0 0 0

Graph 1: The Average Effect of the Beverage on the Stain over Time

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Darkness of Stain

7 6 5 4 3 2 1 0 0 50 100 150 200Coffee Tea Cola Grape Juice Water

Time(Hours)CALCULATIONS To find the average shade of the stain the sum of the trials were found and divided it by the number of trials. Formula: x1+x2+x3 3 =a Sample: 3+2+2 3 =2.5

6 VII. CONCLUSION A. ANALYSIS The hypothesis set forth in this experiment was if the grape juice is used to soak the egg then the egg will have the darkest stain because it has acid that would make the eggshell more vulnerable to stains. This hypothesis was supported because the grape juice had the darkest stain. Graph 1 illustrates that most of the data was collected between 0-25 hours. Then, the overall darkest stain was from the grape juice, then the cola, the coffee, tea, and with water with no stains at all. This data supports my hypothesis because the grape juice had the darkest stains. One way of explaining this data is that the dark coloring of the liquid causes more of it's color to be absorbed by the eggshell while the other liquids are diluted with water making the coloring less bold. Another way to explain this is that generally the liquid with the darkest color had the darkest stain. These results were

conclusive because the results were mostly very distinct. Graph 2 illustrates that the averages of the stains of each beverage shows the grape juice as having the darkest stains. This data supports the hypothesis because it shows the grape juice of having a stain of ten. Then tea has a bit less than cola and coffee and then water has absolutely no staining ability. Another way of explaining this data is that generally the clearer the liquid is, the brighter the stain. These results were conclusive because grape juice had about ten while every other liquid had a stain darkness of 0-6 which is substantially less than the grape juice's stain. As a result of this experiment, some questions that arose were if artificial coloring affected the darkness of the stain. Another question was if the brand of the grape juice would affect it's staining ability. If this experiment were repeated one beverage would be used plus the same type of beverage with more artificial coloring. B. ASSUMPTIONS AND ERRORS It was assumed that the water used to rinse off excessive liquids when the darkness of the stain was recorded did not affect the results of the experiment. It was also assumed that when rinsing the eggshell, all of the excessive liquid was rinsed off. One source of error was that after each trial the egg was not dried off before it was placed back into the liquid, therefore adding a little water to the liquids each time. This could have affected the experiment by diluting the liquid and making the stains brighter than it should have been. In order to eliminate this source of error, the eggshell should be dried after each trial and before it is placed back into the liquid. Another source of error was that whenever each eggshell was taken out one by one to record its stain darkness, it added a few minutes to how long the other eggshells were in the liquid. This could have affected the experiment by darkening the stain slightly for the other eggshells. In order to eliminate this source of error, the eggshells should all be taken out at one time and washed at the same time.

7 BIBLIOGRAPHY Acid Wear on Teeth. Today. 8 Oct. 2007. 10 Oct. 2007 . Gelb, Barbara L. Coffee, Tea, Drinks Non Alcoholic Carbonated, Grapes. The Dictionary of Food. 1st ed. 1 vols. New York: Paddington P, 1931.

Residorf, Bill Re: How are teeth similar to eggshells? 20 may 1997. Mad Sci Network. 22 Sept. 2007

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Teeth Stains: How to Get Pearly-Whites. Stain Expert. 30 Sept. 2007 . What Factors Influence the Color of Teeth? DMHI Inc. 30 Sept. 2007 .

8 ACKNOWLEDGMENTS Special thanks to my mother for not throwing away her eggshells and for obtaining the few materials I needed.

9 APPENDIX 1 Shade Scale 10 0 9 8 7 6 5 4 3 2 1

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