What Happens If You Don't Brush Your Teeth?

Several months ago I wrote a blog post about a children's book called Dragon's Breath by Michael Gordon. In Dragon's Breath, there is a dragon named Joe who refuses to brush his teeth because he thinks dragons aren't supposed to brush them. By the end of the story, Joe finally brushes his teeth... but what would have happened if he didn't? What would have happened to his teeth? This fun science - STEM experiment shows what happens when dragons... and children... choose not to brush them. Keep reading... the results are gross!

Disclosure: Affiliate links to Amazon are included in this post.

Learning About Teeth

Before starting this STEM activity with your students, it's important to introduce the purpose of teeth, the parts of the teeth, and why it's important for everyone to brush them. There are many ways to teach these concepts, so feel free to teach them in a way that works for you. However, your students should become familiar with these related vocabulary words:

• enamel
• decay
• cavity and cavities
• health and hygiene
• germs
• bacteria
• infection

Reading Dragon's Breath

After reviewing the importance of dental hygiene, get your students excited by reading Dragon's Breath by Michael Gordon to them. Dragon's Breath is about a dragon named Joe who refuses to brush his teeth because he thinks dragons aren't supposed to brush them. Discuss why it's important for us to brush our teeth.  Do we want our teeth to look like Joe's?  No!  Brushing our teeth keeps them looking and smelling clean.  But what happens if we choose NOT to brush our teeth for a day or two?  What kind of problems can pop up? What happened when Joe didn't brush his teeth? 

About Dragon's Breath

Author's Summary: What happens when a dragon doesn't brush his teeth? Well…we all heard about the ''dragon's breath’’. That's why learning proper dental care is really important for a little boy and his friend Dragon Joe.

• Teach the importance of brushing teeth in a cute and fun way
• Create more positive attitudes in preschoolers
• The perfect book for kids who love dragons
• Solutions that help keep teeth clean and healthy

🍎 Title: Dragon's Breath

🍎 Author: Michael Gordon
🍎 Illustrator: Michael Gordon
🍎 Publisher: self-published
🍎 Date: October 6, 2018
🍎 Pages: 28

What Happens If You Don't Brush Your Teeth?

Now that you've read and discussed Dragon's Breath with your students, it's time to plunge into this science and STEM activity!

You Will Need

• jar with a lid (glass or plastic)
• hard-boiled eggs (both cracked and uncracked)
• dark soda such as Coke, Pepsi, or Dr. Pepper
• toothbrush
• toothpaste

Day One

This STEM experiment will take a couple of days and is best when completed over the weekend. Start the experiment on a Friday. Finish it on the following Monday.

Eggs and teeth are similar in that they both have layers and contain calcium. They both have a protective outer layer that protects the delicate insides where nerves, blood vessels, etc. are located. Teeth are protected by enamel, and eggs are protected by a cuticle (or 'bloom').  Have you ever had a cavity? Have any of your students had cavities? Cavities happen when a hole forms in a tooth's enamel. When these protective coatings are broken or worn away, bacteria can get into the inner layers and cause infections. Ouch!

Take a look at some unbroken hard-boiled eggs with your students.  Remind the students that these eggs represent our teeth.  What do they look like?  What do they feel like?  How do they smell?  Now take a look at some cracked hard-boiled eggs.  They are still clean and smooth, but the protective coating has been broken... kind of like what happens when we get a cavity.

Many children enjoy drinking soda.  Heck, many adults do too.  Take your hard-boiled eggs... both cracked and uncracked... place them in your jar, pour your dark soda over them, and close the lid for safekeeping.  What do your students think will happen to the eggs?  Do they think the soda will affect the cracked and uncracked eggs differently?  If you have time, record their comments on an anchor chart.  

Two Days Later

After a couple of days, remove the eggs from the soda and let them air dry on a paper towel.  How did these eggs change?  They are stained and have dark spots.  How do they smell?  In some cases, the texture of the eggs may have changed if the soda dissolved the eggs' protective cuticle.  Take a closer look at the cracked eggs.  What happened to them?  Unpeel some of the cracked eggs.  Oh no!  What happened to the egg whites?  

When the eggshells cracked, it allowed the soda to get inside of the eggs. The cracks in the eggshells are like the cavities we can get in our teeth!

Note: Do NOT eat or taste these eggs.  Since these eggs haven't been refrigerated for a few days, you and your students can get food poisoning from them.

Someone in your class will almost certainly ask what would happen if you were to try to get rid of the stains.  That's why you need toothpaste and a toothbrush.  (If they don't ask, pose the question for them.)  Put some toothpaste onto the brush and 'brush' one of the eggs in the same way you'd brush your teeth.  Hmmm... some of the stains will come out... but not all of them!  What can be learned from this activity?

This dental health STEM activity can be modified to meet your learning needs.  You can introduce variables by using different types of eggs, liquids, and toothpaste.  Another variable you can change is the length of time the eggs are soaked in the soda.  What are some other ways you can modify this experiment?  

Many people believe that drinking juice is a healthy alternative to soda. Juice is good for our bodies... but is it good for our teeth? Try soaking some eggs in juice and see what happens...

Did you enjoy reading about this STEM activity? If so, check out these other blog posts for more STEM experiments:

• Plants: Pumpkin Life Cycle STEM Activity
• Hygiene: Pepper and Soap STEM Experiment
• Density: Sink or Float STEM Experiment with Oil and Water
• Chemical Changes: Hot Chocolate Surprise STEM Activity
• Plants: How to Grow Celery from Scraps
• Plants: Dippin' Dandelions STEM Challenge (TikTok Challenge)

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