February At-Home STEAM Activity: Plaque Attack

February is National Children’s Dental Health Month!  

Learn about the importance of good oral hygiene with this fun at-home STEAM activity, Plaque Attack! 

Plaque is a sticky film that forms on our teeth every day. It is the slippery/fuzzy coating you feel on your teeth when you first wake up. Scientists call plaque “biofilm.” Biofilm grows from the sugars in the foods we eat. Brushing and flossing your teeth will remove plaque, so don’t forget… Brush and floss your teeth daily and visit your dentist regularly!


  • 2 Clear Plastic Cups
  • 2 Packets of Yeast
  • 1 Tablespoon of Sugar 
  • 2 Cups of Warm Water 


  1. Label one cup with an “S” for sugar.
  2. Place 2 teaspoons of yeast in each cup.
  3. Add 1 cup of warm (not hot) water to each cup.
  4. Add 1 tablespoon of sugar to cup labeled with an “S”. 
  5. Observe the two cups. 

Extension Questions

  1. What happened to the cup with the added sugar?
  2. What foods do we eat that have sugar?
  3. What should we do to eliminate plaque attacks in our mouths?

The Science Behind the Fun

Yeast are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. Yeast love to be able to eat their favorite sugar in a warm, moist environment where they will multiply in numbers. As the yeast munch away on their sugar, a process called anaerobic fermentation begins to take place. The by-products of this process are alcohol and carbon dioxide, which cause the granules to bloom and become foamy.