Teeth Science for Kids – Why do we need to take care of our teeth

Emma Vanstone


Getting kids to brush their teeth can be a nightmare even with older kids who listen and follow instructions.  Showing them why we need to take care of our teeth is one of the most fun ways to get kids to clean their teeth without any hassle.

Emma from Science Sparks, an educational site which is just bursting with fun, creative science activity ideas for kids, is joining us in the Playroom on BonBon Break with a little experiment about why we need to take care of our teeth that you can do at home with ingredients from the kitchen cupboards.

We obviously don’t want to experiment on our teeth, so we are using eggs to represent them. The shell of an egg has a similar composition to tooth enamel.


  • Eggs
  • Glass or similar kind of container for each condition
  • Water
  • Tea/Coffee
  • Fizzy flavoured drink
  • Vinegar


  • Pour the same amount of fizzy drink, vinegar, water and tea or coffee into your containers.
  • Add a whole egg in its shell to each.

Why should we clean our teeth? Teeth experiment


  • Leave for three days, observing what happens.
  • Remove the eggs and rinse.

Has anything changed?


We found the eggs in the fizzy drink and tea/coffee stained considerably. You can see the difference here between the egg in Pepsi and the egg in water.

The egg in water is our control. We use this so we can easily see the change in colour of the test condition eggs.

Why should we clean our teeth? Teeth experiment


The tea-stained egg is also a very different color to the water egg.

Why should we clean our teeth? Teeth experiment


The shell of the vinegar soaked egg completely dissolved. Can you imagine the effect on your teeth of too much vinegar or acidic foods?


Why should we clean our teeth? Teeth experiment

Why does this happen?

We can clearly see staining of both the tea and fizzy drink-soaked eggs.

Tea is rich in tannins which are known to stain teeth while cola and fizzy drinks are acidic as well as containing products which are known to stain teeth.

Vinegar is acidic and dissolves the calcium carbonate in the shell. The inside of the egg remains intact because the vinegar doesn’t break down the egg membrane. You can also clearly see that the egg has with no shell is bigger than the egg with a shell; this is because some of the water ( perhaps when we rinsed the egg ) has seeped into it via osmosis.

Extension tasks

Can you carefully bounce the egg with no shell? If the shell didn’t dissolve completely, you could put it back in the vinegar for a bit longer.

Can you think of any other drinks which might stain your teeth?

Try covering half an egg with toothpaste, and placing it in vinegar, does the toothpaste protect the egg shell?

This activity is great for helping children to understand why caring for their teeth is so important.


This easy science activity will help illustrate the importance of taking care of your teeth.

 This post was written by Emma Vanstone exclusively for BonBon Break Media, LLC.

 Click to see more from the Playroom

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Emma Vanstone started her parenting blog in 2011 as a hobby and quickly developed a love for social media. Her passion for science education and making science accessible to all led to the creation of Science Sparks later that year, which she has slowly developed into an incredible resource for parents, teachers and anyone who loves science. Emma gets her inspiration from her three children, the questions they ask and games they play. She spends her days drinking too much coffee, attempting to exercise and blogging as much as possible before school run time.