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What Do Sugary Drinks Do to Your Teeth? – Kids Science Experiment

Most kids love fruit juices and soda - this experiment shows them what those things are doing to their teeth!

My kids are pop fiends. (I know some of you are confused right now because you call pop soda.)

Probably because I am a pop fiend. They learn what they see, right?

It’s not one of our finer points.

Anyway, I wanted to show the girls what pop does to their teeth because they are both kind of in a funk where they don’t want to brush without a lot of prompting.

So we talked about how your teeth are made of the same basic stuff (calcium) as eggshells, and so we could soak some eggs in drinks that we like to see what would happen to them over time.

The results, as you can see above, were striking. The kids, Allie especially, really got the idea that these drinks are harmful to her teeth, and she has since been brushing every day without any fuss.



  • 5 raw white eggs – Actually, they don’t have to be raw, but the also don’t have to be cooked, so I don’t know why you would spend the time.
  • 5 cups
  • Masking tape
  • Water
  • A dark-colored sugar-free drink like Gatorade G2
  • A dark-colored fruit juice like grape juice
  • A dark-colored flavor of pop – we used black cherry but cola would probably work better
  • Orange juice (We only had 4 eggs left in the house, so we omitted orange juice, but I was really interested in what would happen with this. My dentist told me that orange juice is pretty close to the worst drink possible for my soft teeth.)


  1. This one is super easy.
  2. Label the cups, one with each drink.
  3. Pour the drink into the cup with that label. Water into the water cup, Gatorade into the Gatorade cup, etc.
  4. Store your cups in a safe spot.
  5. Wait. Check your cups after a few hours if you want. We checked ours before we went to bed and then took them out after about 24 hours.

The Science


The hard shell of an egg protects the soft parts inside, just like the hard enamel on your teeth protect the soft and tender pulp on the inside. Both eggshells and teeth are made of calcium, a hard white substance that also makes up our bones.

Sugar and acids are very harmful to teeth. Acids actually dissolve the enamel, giving bacteria an inroad to begin decaying it, and sugar promotes decay (cavities).

Of course, the water egg was the best after 24 hours. But take a look at the Gatorade egg:


There was definitely a yucky-looking purplish coating on the egg, but it was fairly easy to wipe off with just our fingers. Unfortunately, the slime made the egg slippery and it fell on the floor before I was able to photograph it with the other eggs (in case you were wondering why there were only 3 eggs in the photos, now you know).

This was the black cherry pop egg:


And this was the grape juice egg: (I love the shock on Allie’s face here.)


A study published in the journal General Dentistry found that pop is actually ten times more harmful in the minutes after drinking than is fruit juice. Our experiment showed that the discoloration from grape juice was a lot worse and longer-lasting, but it’s not likely to cause actual decay as quickly as the pop would. So that part of the experiment was a little confusing.

The bottom line is that the sugar, color, and acids in our drinks harm our teeth, and those effects are exacerbated by poor brushing habits.

Extend the Experiment

Take this experiment a step further by brushing the eggs with a toothbrush and then with toothpaste and a toothbrush, to see how much of the stain can be removed from the egg and how much is left. It takes a lot longer than you think to clear away the stain, and you will probably find (as we did) that a lot of the stain is permanent.

© 2016 – 2018, Tara Ziegmont. All rights reserved.

49 thoughts on “What Do Sugary Drinks Do to Your Teeth? – Kids Science Experiment”

  1. I hope this project works out well. I have never done it and I hope that it get me an “A” in science class and takes me to the science fair with a winning prize.

  2. This is also why you should avoid brushing your teeth right after eating/drinking. The acid will weaken the enamel of your teeth, so you need to wait for it to harden back up a bit before brushing.

    • No, not at all, that is not true! I work at a dental office and what we tell patients is to please wash or rinse their teeth asap, the acid or sugar will only weaken the enamel if its not rinsed and stays on the tooth… thus the experiment showed, for a total of 24 hours what happened when they did not brush their teeth. Truth of the matter is that many ppl specially children don’t brush their teeth well and sometimes not at all for several days. Which is why children tend to get more cavities.

  3. does it matter what flavor Gatorade you use and what brand the grape juice and black cherry soda you use? and does it have to be that soda? thnx definitely using this for my science fair project!

    • It doesn’t matter what flavor of Gatorade you use, but it should be as dark as possible. A lighter color like pink or yellow will not show up on the egg. The only thing is, if you want to get results like what we got, you will want to use sugar-free Gatorade.

      As for the juice and soda, you can use any brand. You wouldn’t even have to use black cherry soda, you could use any dark color like cola or root beer.

  4. What would be the point of using sugar free if the idea is to see what sugary drinks do to your teeth? And was the egg shell damaged at all by the sugar and acid in the drinks – or did the dyes in the beverages essentially dye the eggs?

    • the dependent variable is the eggs because they are not changed.
      and the independent variable is the drinks used because they are changed.

  5. Could I leave this over the weekend and see what happens on Monday? For example, if I did this experiment Friday afternoon and left it over the weekend, would that be too long?

    • I don’t think it would be too long. There’s a chance that the eggs in the soda might get a little soft (from the acid eating away at the shell), so you may not be able to use a toothbrush on them, but I’m not sure. The only way to know is to try it! Come back and let me know what happens!

  6. The acid is what is affecting the shells. Leave them in another day and see how soft they get. Track over time if a few days. Also, have a control that you soak in a fluoride mouthrinse. For a sugar beverage to make difference oral plaque ( bacteria)needs to be present. Certain oral bacteria eat and digest the sugar and then produce an acid that softens the enamel.

    Boiling the eggs makes it easier to handle if the experiment goes on for a few days.

    • The control is the one that you don’t do anything to, so that would be an egg in plain water or even just a plain egg that hasn’t been soaked in anything. There is no such thing as a controlled variable. The control is unchanged, and the variable is something that is changed.

  7. How would you recommend making a graph for this for a Science Fair project? We are stuck on how to show this in a graph. It’s my daughter’s first project. Thank you!

    • Hm, a graph? I’m not sure that this lends itself very well to a graph. Maybe a bar graph showing the amount of discoloration? Like, create a scale of 1-5 and rate each egg on how dark its shell got? Just a thought off the top of my head. I really can’t think of anything else though.

  8. Very excited to do this project. My son is in first grade and it will be his first project as well. He has made a shopping list and everything. Ashley, I hope you aren’t at RES in Mississippi. That would be bad to have two doing the same project. Lol

  9. Love this project both a teaching for kids to STOP drinking crappy drinks and easy to do for school project.

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