Science Projects on Tooth Decay Using Sea Shells

Seashells are composed of materials similar to human teeth.

Because seashells are made from calcium carbonate, they can replace human teeth in an experiment about tooth decay. If your curriculum has a dental health unit, add a few hands-on science projects to your lessons to help draw your students in to the material. It may help them remember how to take care of their teeth. Seashells are available at many teacher stores or at online education retailers.

Beverage Jars

Teach your students how certain beverages impact the health of their teeth by immersing seashells in four different liquids. Collect four clean jars with lids and fill one with a dark-colored soda, one with milk, one with orange juice and one with water. Place one white seashell into each jar, and seal it tightly with the lid. Keep the jars in a refrigerator. Ask your students what they think will happen to each seashell and have them record their predictions. After one week, remove the jars and have your students examine the seashells for changes. Have them record any changes they notice. Replace the liquid in each jar and return the jars to the refrigerator for another week. Continue examining the seashells at one-week intervals for three to four weeks. Discuss which liquid caused the most damage to the seashells, and ask your students how they can use that knowledge to protect their teeth.

Keeping Clean

Show your students what can happen if they do not take care of their teeth by brushing them regularly. Discuss how brushing removes food particles so that tooth decay is less likely. Choose two large white shells to demonstrate the importance of brushing teeth. Place each shell on a separate plate. Every two or three hours, drop sugar water on both shells. Brush one of the shells with a toothbrush and toothpaste once a day. Leave the other shell alone. Over time, have your students watch what happens to the shell that never gets brushed. Encourage them to record their observations.

Toothpaste Study

Choose four types of toothpaste, including one with fluoride and one that claims to whiten teeth. Have your students predict which type of toothpaste works the most effectively. Once a day, have one of your students carefully brush each of the seashells with a different type of toothpaste. Always have the student brush the same shell with the same kind of toothpaste each day. Over time, have your students observe the shells and make conclusions about which kind of toothpaste appears to be working best. Have them support their conclusions with observations. Continue the experiment for two or three weeks, making observations every three or four days.

Good Brushing

Talk with your students about the importance of good brushing habits. Give each student a white seashell and have her immerse it in a cup or jar of dark-colored soda. Leave the shells for one or two days until they have turned brown. They do not need to be dark brown, just darker than the original shell. Provide each student with a toothbrush and a smear of toothpaste. Have the students gently brush their shells to remove the color. Discuss how students can prevent tooth decay by brushing all the surfaces of their teeth well.

References

• Blue Ribbon Science Fair Projects; Glen Vecchione
• The Complete Handbook of Science Fair Projects; Julianne Blair Bochinski