Tooth Decay Experiment

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When a team of archeologists recently came across some 15,000-year-old human remains, they made an interesting discovery: the teeth of those ancient humans were riddled with holes. So what causes cavities, and how can we avoid them?


Watch this video first, to learn about cavities.


Now, let’s conduct an experiment to learn about tooth decay. 

Activity Instructions

for Observers (Pre-K through 2nd Grade) and Explorers (3rd Grade through 5th Grade)

We can’t experiment on our own teeth so we are using eggs to represent them, as the shell of an egg is made of a similar substance to tooth enamel!


What you’ll need: 

  • Eggs

  • (3) Jars

  • Tea or Coffee

  • Fizzy Flavored drink 

  • Vinegar 

  • Toothpaste



  • Pour the same amount of fizzy drink, vinegar, water and tea or coffee into your jars. Each jar should contain one type of liquid. 

  • Cover half of two of the eggs with toothpaste. Drop those eggs into the tea/coffee jar and into the fizzy drink jar. The eggs are raw with the shells on. 

  • Add another whole raw egg to the vinegar jar. 

  • Leave for approximately three days. 

  • Remove the eggs. 

  • Rinse the egg kept in vinegar and rub gently until the shell comes away. 

  • Observe the differences between the various eggs. 


Why do teeth stain? 

Tea is rich in tannins which stain the teeth if they’re not cleaned property. Cola and fizzy drinks are acidic and contain products that stain. 


Vinegar (which is acidic), dissolves the calcium carbonate in the shell, leaving just the membrane intact. Try to bounce this egg without it breaking! 

Turn It In

Take a picture of your eggs or a video of your bouncing egg and upload it to Padlet

If you haven't printed the bingo board page, please print it now. Cross off this activity square, since you've completed it.


You'll bring your bingo board print-out to the PS29 garden on  Sunday, May 23 between 2-4pm to collect your prize. If you're not in Brooklyn, email us and we will send you your prize.