I hope you will enjoy this fun science experiment for kids. With some basic materials and a day of waiting, you can show your children what drinks like soda pop and fruit juice to do to their teeth and give them an idea of how important it is to brush every day.
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 tooth enamel is made of the same basic stuff (calcium) as eggshells (calcium carbonate, I think), and so we could soak some eggs in drinks that we like to see what would happen to them over time. The discoloration of the white egg would be similar to the discoloration of our white teeth over time.
The effects of different drinks, 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.
Materials
- 5 raw white eggs - Actually, they don't have to be raw, but they also don't have to be cooked, so I don't know why you would spend the time.
- 5 cups - I thought about buying clear plastic cups, but the liquid is dark, and you can't see the eggs anyway, so use whatever cups you already have.
- Masking tape
- Water
- A dark-colored sugar-free drink like Gatorade G2 or a diet soda
- A dark-colored fruit juice like grape juice
- A dark-colored flavor of regular soda or pop - we used black cherry but a cola like Pepsi or Coke 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 because the acid attacks the enamel and the dentin inside.)
Instructions
- This one is super easy.
- Label the cups, one with each liquid.
- Pour the drink into the cup with that label. Water into the water cup, Gatorade into the Gatorade cup, etc.
- Store your cups in a safe spot.
- 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 tooth 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.
More Cool Science Experiments for Kids
While you're here, check out a few of our other simple science experiments for kids:
I hope you enjoyed this fun science experiment for kids. With some basic materials and a day of waiting, you can show your children what their drinks to do to their teeth and give them an idea of how important it is to brush every day.
Abdul rehman says
It was a good experiement
Josiah says
This is good for the kids and me because I will never drink bad food
jessy says
so whats the independent variable and the dependent and the controlled ?? how would we make a graph for this experiment???
Tara Ziegmont says
I'm not going to tell you the variables because that would be like doing your homework for you. I don't know how you would graph this experiment. It doesn't really lend itself to a graph.
diamond says
i like this project i think it is very cool
Ella says
How much of the liquid do we pour into the cup?
Tara Ziegmont says
It doesn't really matter exactly how much liquid you put in as long as the egg is fully submerged.
Tommy says
Hi. i need help. im doing this for science fair and im confused on how to make a graph on this PLZ help its almost due!!
Emily says
Hey I have a question will it decompose the egg shell or will it just change the color
Tara Ziegmont says
It's sort of doing both. I think, if you left the egg in the soda for longer than a day or two, the shell may eventually get soft. It's the acid in the soda that does that. I think juice is probably also acidic though not as much as the soda.
Kiera Breaux says
How Do You graph this? Need answers ASAP!!!
Tara Ziegmont says
I don't really think you could graph this. It isn't really a quantitative project that would lend itself to graphing.
Karen says
Hi! I’m thinking of doing this project with my son for his first project. In regards to data. I think we’ll use the product label to graph the amount of sugar per serving in each drink and the intensity of color on the egg. We are excited to see the correlation between the amount of sugar per serving and stain on the eggshell. Just our thoughts!
Cassandra says
My daughter is also doing this for her first project. We are going to see what it does over 5 days (checking the eggs racha day for the effects). Using the product labels is a great idea. It also got me thinking that measuring the pH balance of each drink would also be great to measure.
Swizel says
What precautions should be taken while doing the experiment
Carter says
7th grade science fair is going grate!
Blake says
This project will work 100% YESSIR
Briel says
How would you recommend graghing the eggs?
me says
love this project imdoing for the science fair!!!!
this is gonna be awesome!!!!
Joanne A. says
I'm in third grade. I love this science experiment! I know I will get a prize!
Joanne A. says
I don't know how to write a citation for this. I need it fast! My science project is due today!
Joanne A. says
When was this page published?
Olivia P says
I really wanted to do this kind of project. When I found this website I got so happy. Thank you for helping me do my project. I hope to win a prize in my schools science fair and in the district science fair!
Emily F. says
I am super excited to try this! It looks like a great way to learn about the way sugary drinks affect your teeth.
LoL says
Where is the control? Are you sure there are no other variables? Why didn't you use the same color egg for each one, you cant use brown eggs and white eggs that would change the outcome!
Bee says
i wanted to ask can i empty the inside of the eggs and then dip them in the liquid because i am scared my son might break the eggs Infront of the judges =D
Tara Ziegmont says
Of course! It will still work.
Ayden says
What is the Dependent Variable in the experiment?
Bella says
I"m doing this as a science fair project!!! I'm so exited! Thank you! The food on the side looked so good to. Can't wait to try