Brush Up: A Toothpaste Experiment

3.6 based on 103 ratings
Updated on Apr 7, 2014

After eating, a sticky coating called plaque forms on our teeth. We must brush off the plaque or it could turn teeth from a nice pearly white to a dour yellow or brown. Plaque can also lead to cavities, which are no fun at all. This activity uses a hard-boiled egg as a pretend tooth and shows what happens if plaque goes unchecked. Reluctant brushers might change their attitude after seeing the results of this amazing experiment!

What You Need:

  • One hard-boiled egg with white shell
  • A glass
  • A can of cola, or other dark brown soda
  • Toothpaste
  • Toothbrush

What You Do:

  1. Carefully place the hard-boiled egg into the empty glass.
  2. Pour the can of dark brown soda into the glass, making sure the egg is completely submerged in liquid.
  3. Ask your child to guess what might happen to the white egg. Leave the egg in the cola overnight. 
  4. The next day, remove the egg from the liquid. Ask your child to describe what happened to the egg. How did it look before it went into the glass? How does it look now?
  5. Provide your child with a toothbrush and toothpaste and encourage him to remove the stains from the egg’s surface. Explain to your child how the egg is like a tooth and discuss what might happen if teeth aren't brushed!

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