Discovery and Science

Germs + Food = Cavities



This small group demonstration shows children how the combination of germs and food cause cavities. Imagine that this bowl is your mouth. We know that germs live in this mouth (add pepper to bowl) the black dots are the germs. When we eat a little sugary food (pour in backing soda) the germs start eating the food (pour in some vinegar.) What do you notice? What do you think is happening here? Encourage responses and look for what you have introduced to the children about germs “eating” teeth. Acknowledge responses and introduce or repeat that teeth are getting weak. What happens if we add more food? (add more baking soda/vinegar)


The tooth is even weaker. The tooth is getting holes. Cavities are forming. Our teeth get holes when sticky, sweet food mixes with the germs in our mouth—they make an acid attack. The acid eats holes in our teeth. These holes are called cavities. If we don’t stop acid attacks, the decay becomes bigger holes, called cavities. What can we do to prevent acid attacks and cavities from forming? Acknowledge children’s responses.


This activity is also appropriate for Family Nights.

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