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.
LaDereka says
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.
gaya says
Same. I am in 5th grade and i hope i go home with a prize.
yeeter says
same but i am in 6th
yeeter says
if this does not get us an A i will dance when i am sad
yeeter says
i will dance and be normal again............... and i will get A next time
PoshPatdis says
same but I am in 7th and doing this for science fair
Jackie says
Same!
Uprise says
same! im in 7th and doing it for a stem fair
Alex says
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.
LEXI says
I'm doing this for my science fair project!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
JE says
I am doing this too!! Hope it's fun for me and you guys, also!
Sammantha says
Is this considered 7th grade advanced level
Tara Ziegmont says
I think that would vary by school and teacher. You'll have to use your own judgement. It would also depend on your accompanying research, analysis, and discussion.
Tiana says
Am doing this and think this was very helpful thx
peyton says
did you measure out the drinks or does it not matter my teacher said it is best to measure anything with liquid what measurement would you recommend
Tara Ziegmont says
It doesn't matter. If you need a measurement, use 12 ounces of each liquid.
wyatt says
me too
peyton says
what would you suggest a graph, chart, or table for data analyzing? I'm trying to figure out what would be a good idea to report. thank you!
Julie says
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.
Marta says
Thank you so much on this project now my kid is doing this for her Science Fair project!
Pauline says
Did you use eggs with shells on? And were the eggs hardboiled?
Can't wait to do this with my kids.
Tara Ziegmont says
Shells on, raw eggs although it doesn't really matter whether they're raw or not.
Darius says
I did the eggs boiled
me says
how did it work out
Justin says
what are the different variables of this experiment?
Tara Ziegmont says
If I told you, wouldn't that be like doing your homework for you? There is an independent variable and a dependent variable and a control.
Shawn says
Can you at least tell us how to measure the scientific concept?
Tara Ziegmont says
I'm not sure what you are asking.
Darius says
Can you use absolutely any cups?
Tara Ziegmont says
I don't know why not.
cool dude says
i am doing a since fair project and i though this would be cool
Patrick Mullaney says
doing this for my science fair project!!!!
Patrick Mullaney says
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!
Tara Ziegmont says
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.
Sharalyn Patching says
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?
Tara Ziegmont says
The point is to see what sugar-free drinks do to the enamel of the egg. Why wouldn't you want to test other substances? There's no reason to limit it to just sugary drinks. It's interesting to see how the sugar-free drinks react as well.
Tara Ziegmont says
To your other question, all three damage the teeth - sugar, acid, and dyes.
nrix says
is it ok if im using the chocolate-egg ( the egg is chocolate colour )
Tara Ziegmont says
Are you saying that you're going to use a brown egg? I don't think that would work very well. White shells show the changes much better than brown ones would.
me says
What would be the independent variable, the dependent variable, and the controlled varable of this project.
mariah says
the dependent variable is the eggs because they are not changed.
and the independent variable is the drinks used because they are changed.
Mayleen says
I don't think that the egg would be the dependent variable because how are you suppose to measure the egg? It doesnt make sense.
Tara Ziegmont says
You are correct. The egg is not the dependent variable.
Candace Spicer says
What would the dependant variable be?
Tara Ziegmont says
I'll be happy to help you with the experiment, but I won't give you the answers to your homework.
me says
What is the controlled variable
Megan says
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?
Tara Ziegmont says
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!
Renee Johnson says
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.
Jaleigh Levine says
Using this for science fair!!!!
Lisa says
What is the controlled variable?
Tara Ziegmont says
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.
Ashley says
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!
Tara Ziegmont says
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.
Teresa says
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
Tara Ziegmont says
Good luck!
Allyson says
Would you keep the eggs in the fridge or at room temperature?
Tara Ziegmont says
It doesn't matter. I keep mine in the fridge and didn't warm them up prior to the experiment.
Mia says
I did this project for a science fair, but i have no clue how i am supposed to graph my results. does anyone know?
Tara Ziegmont says
I guess it depends on what kind of graph you're looking for? What's your requirement?
Kami Beth says
This is my first time doing the experiment, i am doing it with i partner i can not wait
Daizy says
Love this project both a teaching for kids to STOP drinking crappy drinks and easy to do for school project.