7th grade science project ideas


Which toothpaste will give you the whitest teeth?

Do you want to have the brightest smile in your class, in the whole school? Then perhaps you should consider this interesting project which will help you determine which toothpaste will give you the whitest teeth.

We clean our teeth with toothpaste which is a thick substance that consists of a binder, as well as fluoride, flavoring oils, and a liquid to give the toothpaste plasticity. Stains that occur on teeth are most often plaque stains. These and other stains can be whitened using tooth-whitening processes. The innermost part of the tooth is called pulp. It is made up of connective tissue, blood vessels, and nerves. Blood vessels nurture the tooth whereas the nerves send sensations of pain to the brain. Dentin is a very hard yellow material that makes up most of the tooth. It is harder than bone and is mostly made of mineral salts, water, and some living cells. Enamel lies over the dentin is the outer most covering of the crown. Cementum lies over the dentin in the root of the tooth. The periodontal ligament consists of small fibers. These fibers extend through the cementum.

The most common cause of tooth stain is called plaque. It is a sticky film that is made up of saliva, food particles, and bacteria. Plaque is a source of toxic material that takes part in the discoloring, and decay of teeth. Inadequate cleaning habits and poor diet may also contribute to the discoloration of teeth.

Almost all toothpastes contain fluoride, a chemical compound made up of fluorine; fluoride helps to resist tooth decay. Binders are put into toothpaste to hold the toothpaste together. Most binders are made up of gum tragacanth, seaweed derivatives, or cellulose derivatives. Flavoring oils are put in the toothpaste to flavor it. The flavoring oil consists of saccharin, or cyclamate. Both oils are often used together. Liquid is added for plasticity. The liquids are glycerin and water. Tooth powders are almost identical to toothpaste except tooth powders do not contain liquids or binders.

1. Shade guide. To find a dental shade guide, we suggest you go to ebay and enter "dental shade guides". You should find twenty or more listings for as low as $5.00. Another idea is to go to your dentist and ask him (or her) to either give you a shade guide or borrow one.

2. Several small white ceramic tiles to use as teeth samples may be used if you cannot obtain real extracted teeth samples

3. Needle nose pliers

4. 100 mL Dixie cups

5. 200 mL cocoa, tea, or coffee

6. 200 mL raspberry or strawberry soda

7. 5ft wax paper

8. Toothbrush

9. 100 mL Baking Soda and Peroxide, about half and half

10. About 100 mL of 3 or 4 different brands of toothpaste

Suggested procedures…

1. Gather materials.

2. Put on latex gloves.

3. Analyze the color shade of each tooth by matching it up with the right color on the shade guide.

4. Fill graduated cylinder with 50mL coffee.

5. Pour coffee into a Dixie cup.

6. Place one tooth (or ceramic tile sample) into the Dixie cup and mark it C1.

7. It should remain in the coffee for 48 hours.

8. Remove the tooth from the coffee and place it into a zip lock bag that is marked C1.

9. Repeat steps four through eight on six of the teeth, except mark the cups C2, C3, C4 and so on.

10. Repeat steps two through nine on six of the teeth, using Strawberry soda or Kool-Aid. Mark the cups properly for identification.

11. Record the color of all the teeth or white small ceramic tiles after being stained by matching it with the correct color on the shade guide.

12. Take two teeth from the coffee group and put them in another Dixie cup marked "Coffee and whatever tooth whitener will be used on those teeth." Do this to all the coffee stained teeth.

13. Repeat this procedure with the soda stained teeth as well and be sure to record the toothpaste being used. Do this to all the teeth.

14. Brush the stained teeth with the assigned toothpaste.

15. Do this by holding the tooth with needle nose pliers and brushing the tooth at least 75 strokes on the face of the tooth.

16. Compare the tooth to the shade guide by matching it with the correct color on the shade guide. Record the data found.

17. All perform all of the above procedures using the baking soda and peroxide solution as a control to see how this formula cleans teeth compared to commercial tooth pastes.

CLICK HERE for complete details on this project.



seventh grade science fair project ideas


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