How to Use Eggs as a Dental Hygiene Experiment

Because of the similarities between tooth enamel and eggshells, many elementary classroom teachers use hard-boiled eggs to demonstrate proper dental hygiene. However, these experiments and demonstrations don't have to be left to the classroom alone. Using items typically found around your house, you and your child can do some of these egg-speriments too!

Instructions

Difficulty: Easy

Things You’ll Need:

• Hard boiled eggs, preferably with white shells
• Dark-colored soda
• Toothbrush
• Toothpaste containing fluoride
• Jar or cup
• vinegar

Perform the Soda Experiment

1. Boil 2 to 3 white eggs. You will only need 1 or 2 eggs for the experiment, but since the shell needs to remain intact, it's a good idea to boil a few extras.
2. Talk with your child about the importance of brushing his teeth every day, making sure to explain about plaque and how, over time, it can leave teeth discolored.
3. Ask your child what types of drinks she thinks might damage her teeth, leading her to think about soda.
4. Fill a small jar or cup with dark soda. As a side experiment you may want to fill one jar with regular soda and one with diet soda to see if there is a difference as to how it affects the "tooth." Place a hard-boiled egg in each cup and leave it there overnight.
5. Check the egg in the morning. Both you and your child will notice that the eggshell is stained from the soda. Talk through the connection between the eggshell and tooth enamel and ask your child what he thinks you can do to remove the stains. As a clue, take out a toothbrush and a tube of fluoride-containing toothpaste.
6. Place some toothpaste on the toothbrush and let your child brush the stains off the egg.

Perform the Vinegar Experiment

7. Give your child a hard-boiled egg to examine carefully--letting him crack it open if he wishes. Ask him what purpose he thinks the shell serves, ending in a discussion about how the hard shell protects the soft egg on the inside.
8. Ask your child to feel her teeth with his tongue and tell you whether they are hard or soft. Explain that the hard outside lining of teeth is called enamel and is designed to protect her teeth like the eggshell protects the egg.
9. Fill a jar two-thirds full with vinegar, explaining to your child that the vinegar is a lot like the "plaque bugs" that form in our mouths from the combination of the food we eat and our saliva.
10. Put a hard-boiled egg in the jar, cover it and leave it in place for up to 2 days, making sure to let your child know this is akin to not letting the egg "brush its teeth." Remind your child periodically about the egg and ask him what he thinks would happen if he didn't brush his teeth regularly.
11. Return to the jar, remove the egg and note how the shell is soft and pitted. Help your child make the connection that her teeth needed to be brushed regularly to keep them strong.

Tips & Warnings

• Be careful to emphasize that the enamel on your child's teeth won't break down if he forgets to brush a time or two. Some children become very fearful after watching the eggshell break down and need reassurance that their teeth won't immediately follow suit.