Which toothpaste whitens teeth the best?
Dental-health science projects are fun to do. They're something kids can relate to and hopefully learn something from. There are many options for discovery when designing a dental-themed science project, such as: How long should you brush to remove plaque? Which works better---an electric or manual toothbrush? What does sugar do to tooth enamel? A relatively easy science experiment is to test and compare toothpastes that are advertised as the "best whiteners." Ask your family dentist if he could supply you with a tooth-shade guide and teeth that have been pulled for your experiment.
Instructions
The Experiment
1. Mark three paper cups as "Coffee 1," "Coffee 2" and "Coffee 3." Mark three more paper cups for grape juice, and three for soy sauce.
2. Heat each of the three liquids (coffee, grape juice and soy sauce) in the microwave on high for approximately 45 secs. to 1 minute (or, use the beverage setting). You want the temperature hot (approx 168 degrees Fahrenheit) but not boiling. (Hot liquids stain teeth easily, because temperature changes cause teeth to expand and contract, which allows stains to penetrate your teeth.)
3. Pour 2 oz. coffee into each of the cups marked "coffee." Do the same with the grape juice and soy sauce.
4. Place one tooth in each of the nine cups of liquid. Allow the teeth to sit in the solutions for 48 hours.
5. Label each zip-close bag as you did for the paper cups, using three for each liquid.
6. Remove each tooth from liquid, using pair of tweezers, and place it into the zip-close bag with the corresponding label.
7. Compare each of the now-stained teeth to the shade chart.
8. Record the solution, number and color of each tooth.
9. Label the remaining nine paper cups as in Step 1.
10. Write below the identifying solution/numbers on each of marked cups in the coffee group. Label one "Crest," one "Colgate" and one "Rembrandt." Repeat with the marked cups for grape juice and soy sauce.
11. Remove each tooth from its zip-close bag and place in the corresponding cup, each marked with a different toothpaste. (You should have one coffee-stained tooth in each of the three different toothpastes, one grape-juice-stained tooth in each of the three toothpastes, and one soy-sauce-stained tooth in each of the three toothpastes.)
12. Designate and mark each of the three toothbrushes with one of the three toothpaste brands. Use each brush with the designated toothpaste only.
13. Pick up the first tooth with the tweezers. Brush the tooth 100 strokes with the toothpaste brand named on the cup. Repeat with the remaining teeth.
14. Compare the brushed tooth color to the shade chart and record the color. Analyze the results and record your findings.
Tags: each three, grape juice, paper cups, tooth each, each tooth, grape juice sauce, juice sauce
