-- The Home Page of the Finishing Industry
A website for Serious Education, promoting Aloha,
& the most FUN smiley you can have in metal finishing

topic 13883

Science Fair - "The Truth About Toothpaste"


I am doing a science fair project on.."Which brand of toothpaste works the best." I applied toothpaste to an egg and left it sitting in vinegar. I've tried 5 different brands to see the effects. I was told to try putting it in vinegar--what is the effect supposed to be? If you have any information or ideas to try this project different, I would really appreciate it.

Malan S. [last name deleted for privacy by Editor]
- North Ogden, Utah


Malan, the first thing to ask yourself is: What is meant by the phrase, "works the best"?

The best at cleaning teeth?
The best protector of teeth?
The best at cleaning eggs?
The best at polishing silverware?

Until you can answer that question, you won't know why someone would suggest putting an egg coated with toothpaste into vinegar! Once you have determined what the toothpaste should be doing, you can compare brands. It is pointless to compare brands before you know the purpose of your test. Perhaps you can find out how to evaluate the toothpaste by writing down what claims are made on the box. Then think of some way to determine whether or not the toothpaste lives up to those claims. Does the box say that it makes your teeth whiter? Prevents decay? What way would you test whether or not it makes teeth whiter? What way would you test whether or not it prevents decay? Once you have some idea of your test criteria, you can compare the brands to a standard that you have devised.

You might do an internet search on some dental sites, rather than for better results! Unless you were testing toothpaste for its polishing ability on metal and not teeth?

I wish you good luck in learning about scientific method.

Ronna Erickson
- Amherst, Massachusetts

Well said, Ronna

Bill Reynolds
Bill Reynolds
   consultant metallurgist
Ballarat, Victoria, Australia

We sadly relate the news that Bill passed away on Jan. 29, 2010.


Hello Malan,

I think that the object of the experiment is to see which toothpaste best protects the teeth from dental caries. What happens with teeth is that plaque forms on the teeth and bacteria produce acid under this plaque. I would guess that someone is concluding that egg shell is similar to dental enamel and that if you can protect an egg shell from acid attack then you will also protect teeth in the same way.

I do not know what an eggshell is made from but I seem to remember that there is a high level of calcium carbonate in it. Vinegar attacks calcium carbonate quite vigorously. I know it is possible to completely remove the shell from an egg by dissolving it in vinegar.

Tooth enamel is made from carbonated calcium hydroxy-apatite. I do not know if the two are sufficiently similar for your test to be valid. What I think the idea is that after brushing an egg shell with toothpaste, does it resist acid attack any better than untreated shell. Now go out there and get a whole lot more information on the chemical structure of enamel and egg shell, read about the effects of fluoride on teeth, run your tests, draw your conclusions and have a great science fair.

You need to do a lot more work to get a good presentation. There are scientists that have spent years and years researching this problem and there is LOTS of information on the web. Do lots more reading before you even think about starting the experiments.

Good luck,

John Holroyd
- Elkhorn, Wisconsin


Hey Malan,

What's goin on I am doing the same project for my 8th grade science class and my science teacher told me that using eggs to represent teeth is very smart because egg shells have calcium just like teeth so they act kind of the same. How I am doing my project is I am staining 36 eggs, using 6 kinds of toothpaste and trying each of them 6 time to make sure my experimenting is correct. I am staining 18 of the eggs with koolaid and 18 of them with coffee to make sure the tooth paste works the same with different substances. Then I am going to mix all 6 toothpastes separately with water(make sure to measure the toothpaste and water),then I am going to put an equal amount of the toothpaste and water into 36 cups and place all of the eggs into them and then every 10 minutes take them out and check to see which one is the whitest. Make sure to use the 5 scientific procedures state the problem, do the research, make a hypothesis, experiment the problem and make a conclusion. I know you might not want to take advice from an 8th grader but I think my advice is better than the ones I've seen so far. I hope I have helped in any way.

Naomi M. [last name deleted for privacy by Editor]
- Ellensburg, Washington



I can answer why use an egg to find out which toothpaste works best. An egg has a surface and it is called enamel the same enamel is on the surface of our teeth. That's why an egg is similar to teeth.

Cynthea [last name deleted for privacy by Editor]
- Toronto, Ontario, Canada

So You Have to do a Science Fair Project


Hey what's up I am doing a project on that too & I don't get it....

Erin [last name deleted for privacy by Editor]
- Ft. Walton, Florida


Actually to answer your original question about the vinegar. Vinegar should be used in advance of the experiment. You soak the gee shell in the vinegar overnight to soften the shell. The acidity from the vinegar softens the shell just as the acid in your mouth can cause a tooth to weaken and decay.

Robin S. [last name deleted for privacy by Editor]
- New Milford, Connecticut


Here is the hypothesis you should use:

Science Fair Hypothesis:
My hypothesis states that the tarter control toothpaste will be the best at cleaning teeth because it also contains fluoridated toothpaste as well as tarter control toothpaste. My hypothesis also states that mouthwash will do the worst because all the others are toothpastes.
Here is a list on the ranking I would give each (greatest to least):
1. tarter control toothpaste
2. fluoridated toothpaste
3. non fluoridated toothpaste
4. baking soda [linked by editor to product info at Amazon]
5. mouthwash

Alex A [last name deleted for privacy by Editor]
- Ferndale, Washington,


Dear Malan,

I am doing the same project and I am in 7th grade. I am doing the same thing that Naomi is doing on my Science fair project! Sounds like your havin some trouble, but doing a project is really hard. Make sure that before you start that your project is measurable, observable, and repeatable. That is a must for all science. first decide what exactly you want to find with your project. Then if you wanna find out what toothpaste is best for decay, then put the egg in vinegar. then just brush that egg with all of your toothpaste options. If you wanna find out what whitens best, then stain your eggs with 2 or 3 different substances, and then brush them with all of your toothpaste options. I am just curious, how old are you, and what grade are you in, and when is your project dew?

good luck, in Him, Chrissy

Chrissy J. [last name deleted for privacy by Editor]
- Atlanta, Georgia


Science Fair Projects

I am doing the exact same project as you all. At first I wasn't even doing one but I came up with this amazing idea, because I got tired of watching all of the commercials so I wanted to figure out which one truly works the best of Aquafresh, Colgate, Crest, and Aim.

Shykedra H. [last name deleted for privacy by Editor]
- Dallas, Texas


My son is interested in doing a similar project. My question is should the eggs be hard boiled first? I am worried that they will begin to stink if we do the project too far in advance. Any additional comments or suggestions would be most welcome.

Thank you.

Pooski DeMichele
- Westernport, Maryland


Well I wanted to answer your ? on should you hard boil the eggs or not, well Pooski if your worried about it smelling then after the egg's are hardboiled refrigerate them for an hour or two, it will reduce the smell and will be easier to work with.

Kelly M [last name deleted for privacy by Editor]
- Oxford, Connecticut



I was wondering if anyone could help me with how to write up an observational science fair. I am trying to find out which tooth cleaner works the best at preventing tooth decay from sugar and acid. My results were going to be photographs with an explanation. Is this sufficient enough? Are there any other ways of writing up results apart from graphs or charts? Also, if anyone knows how to answer this question: How will you ensure your results are reliable? Because I did not repeat test as this science fair is purely observational. Thank you to anyone who can help me with any of these questions.

Rebecca G. [last name deleted for privacy by Editor]
Student - Hamilton, Waikato, New Zealand


Science Fair Projects for Elementary Schools

Hello, I am doing a project with an eggshell too. The only different thing is that I'm testing the strength of it when soaked in a carbonated drink. If you could just send me the ingredients of an eggshell or the impact strength of a white eggshell. Thanks!

Travis C. [last name deleted for privacy by Editor]
middle school student - Edgewood, New Mexico


What toothpaste cleans eggs the best out of : Colgate, Crest, Aquafresh?

Deshanatala M. [last name deleted for privacy by Editor]
middle school - Tallahassee, Florida


Hey I'm doing my 8th grade science fair project on which tooth paste works the best. I am using tile and soaking them in coffee, coke, and kool-aid for 30 minutes a piece. I am going to use different toothpaste and brush each tile for 2 minutes. Then I will be able to see which 1 works the best. I have a question though. Where do I find information for this project like research I mean because I have to do a research paper. ok then buh bye!

Sarah [last name deleted for privacy by Editor]
- Louisiana


Well said, I'm doing the same project, and the enamel in a humans teeth are similar to that of an egg shell, where as the basis of vinegar is an acid, in comparison to that of plaque in teeth. The person meant that if an egg coated in toothpaste did not swell it could withstand the plaque in teeth as well as cavities. If the shell swells and explodes then the vinegar penetrated the eggs shell, meaning that, that toothpaste did not work.

Keith B. [last name deleted for privacy by Editor]
- Garland, Texas



I am doing the exact same project as all the rest of the ones who are testings toothpaste. My question is how do I get started? I am thinking about testing the eggs using food coloring. Then when the eggs are finished soaking over a day I plan on brushing the eggs of with the toothpastes Crest or Colgate? Should I use more than just those 2 brands. Where do I go from there because I have to use graphs too. How do I proceed with this topic?

Kayla S. [last name deleted for privacy by Editor]
student - Fort Worth, Texas


I am doing the same project as you other people are , except I am soaking my egg in tea! The one thing that I don't know is the difference between the egg shell and tooth enamel. I think that's what its called! OK by people!

Marilee W. [last name deleted for privacy by Editor]
student - Hendersonville, North Carolina



I just finished my science fair project about staining eggs and brushing them to see which brand of toothpaste whitened the best. I then got 97.5 and going to Regionals. I am supposed to do more research. And I can't find my answer anywhere. My question is, Does the type of toothpaste affect my project and conclusion? Does any of them slow down the whitening or help whiten (tarter, breath, plaque control).

Please I would like to know before I go on to regionals.

Thank you,

Tracee B. [last name deleted for privacy by Editor]
- St. Paul, Minnesota


Hey...I saw this posted and I am also doing a science project on toothpaste. I am making agar plates and putting a swab from someone's mouth on the plate and then I am going to put it in the incubator to grow the bacteria. Then I will split the bacteria into 4 sections and put watered down toothpaste on the sections (a different kind of toothpaste on each section). And then where the bacteria doesn't grow you measure that and which ever section has the biggest ring is the best. I hope this helped.

Amelia M. [last name deleted for privacy by Editor]
- Lawrence, Kansas


Hey, I'm doing a similar project as you guys and are unclear of what to do! My project is do very soon and I'm in a bit of a time cruncH! I was thinking that you brush the egg in toothpaste and then put it in coke, tea, coffee, etc. to test the protection of the toothpaste but the directions are unclear. My teacher had NO input at all and now I am quite confused. I was wondering if this works or should I change my topic to which toothpaste whitens the best.Please respond!

Sarah D. [last name deleted for privacy by Editor]
- Stonington, Connecticut


I was just gonna start a project just like that but I still really don't know what to do like planning and like what to use please help!

Makalyn M. [last name deleted for privacy by Editor]
- Idaho


Please try you best at expressing your question in terms of what you've read on this page and what questions it left you with, Makalyn. These nice people have put in a lot of effort; please don't ask them all to just start over from scratch! And education is about progressing by building upon what you already know. Good luck.

Ted Mooney, Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey


I just so happen to also be doing a very similar project to you all....its due in a little over a week! To see which toothpaste whitens the best out of Crest, Colgate and Aquafresh I decided to use the tea method. Your supposed to take some tea and put toothpaste in the tea, if the tea loses its color then that means that the whitening the toothpaste works...but does ANYBODY out there know how long your supposed to wait on the toothpaste in the tea before concluding anything?...Please Help and FAST!

Drew M. [last name deleted for privacy by Editor]
- Kahnawake, Quebec, Canada


Sarah, I think tiles are a great idea! I am doing a project like yours with tiles. Tiles also have enamel, like teeth. I'm seeing which toothpaste whitens better.
What happened to your experiment?

Rebecca [last name deleted for privacy by Editor]
- New Jersey


I am doing this project for my year 10 major assignment and I just wanted to thank everybody that has written on this website as it has helped me greatly.

Natalie [last name deleted for privacy by Editor]
- Sydney, Australia


k... I'm going to do my project on the toothpaste testing... it sounds interesting to me since I'm not really into science.. but I wanna know if I could break the egg instead of keeping it with all the stuff inside.. like just use the shell. If anyone knows the answer to my question please write back! thanks!

Jessica W [last name deleted for privacy by Editor]
student - Ottawa, Ontario, Canada


I tested which toothpaste whitens the best. I tested Colgate, Crest and Aquafresh. I brushed a hardboiled egg that was soaked in tea for 24 hrs. In my experiment Crest whitened the best!

Libby [last name deleted for privacy by Editor]
- California


Hey everyone! I am in 7th grade and I am also doing a science fair project about toothpaste. My title is: What type of toothpaste whitens the best. I went to the store and I thought it would be very easy to pick out a few toothpastes. NOT! there were so many different types! Should I use Whitening toothpaste or different flavored toothpastes or just random types from different brands? does the flavor matter? Please help me! Thank's Y'all

Elli D. [last name deleted for privacy by Editor]
- Atlanta, Georgia


Hey Malan what's happening, what school do you go to? Because I think I know you, anyway I wanted to do the same thing for science fair. how long do you leave the eggs in vinegar? anybody please answer fast fast fast

Chelsea B [last name deleted for privacy by Editor]
- Harrisville, Utah


I'm also doing this experiment, and although I can find plenty of information on toothpastes, I can't find many experiments similar to mine with their findings. This is important because my teacher is requiring me to use examples from past experiments in my project. If anyone knows of any specific websites with results on it, please post it. I'd be very grateful.

Sariah S. [last name deleted for privacy by Editor]
- Charleston, West Virginia


Hey, I want to do a science project on which toothpaste works the best for cleaning (not whitening) teeth and I don't know whether or not to soak the hard boiled eggs in vinegar before putting the toothpaste on or to put the toothpaste on before putting the eggs in the vinegar. I also don't know how long to put the eggs in the vinegar either way.

P.S. I am in the 10th grade

Angel R [last name deleted for privacy by Editor]
student - Gainesville, Florida


I have a question I still have no idea why you should put the egg in vinegar,do you have to put all the eggs in it or it is just acting like an example of how stuff stain the teeth?


Ahmad I. [last name deleted for privacy by Editor]
- New York


I am trying to pick out a science project to do for a science report thingy. I think I will brush the eggs with toothpaste first then put them in different drinks. The eggs that are the most stained will have the least effective toothpaste,right? I hope this helps someone.Good Luck!

Kristyn S. [last name deleted for privacy by Editor]
- Pardeeville, Wisconsin


I just found this on the Crest website. It will help a lot of you on why you use Vinegar on this project. It gives details on how to perform the science experiment.

Lori W. [last name deleted for privacy by Editor]
- Corona, California


I actually work in the dental field and the egg shell is to resemble the structure of enamel on teeth. When toothpaste is placed on half of the hard boiled egg and the whole egg is placed in vinegar, the half of the egg that does not have vinegar will appear spongy from the acid eating away the calcium from the shell. The toothpaste side has fluoride and the shell is protected from the acid. This is an example of how acid bacteria can destroy the enamel of teeth and how fluoride is an important element for human teeth.

Cathy P. [last name deleted for privacy by Editor]
- Indianapolis, Indiana


I wanted to know what you do after you soak the eggs in water and for how long you leave them there?
thank you

Linda R [last name deleted for privacy by Editor]
- Stratford, Connecticut


Hi- I thought of using a natural or tumbled marble instead of the eggs. They contain a significant amount of calcium and will react with mild acidic compounds such as vinegar and will stain and can be brushed and cleaned to give accurate results. I am the parent of a 7th grader and work in the geologic field and have some knowledge of the amount of calcium in certain stones. A very common and easily obtainable marble called botticino will work the best for this experiment. It contains about 37% calcium and can be cut rather easily with a thin grinding wheel (sorry kidos -- cutting must be done by an adult) or even obtained in the proper size in the shape of large teeth to enhance your presentation..(...don't be tempted to use cream travertine because it contains way too much calcium for acceptable results and stones such as granite contain no calcium... however other light colored marbles may be used....then proceed as you would with the eggs... Hey--just an idea!

Mark G. [last name deleted for privacy by Editor]
- Baton Rouge, Louisiana


Most toothpastes don't do what they say they do and most people think it doesn't really matter. But don't you want good looking teeth so I found out that you have to check what it "says" it does and most toothpastes don't work real well buy named brands not the no name brands so remember to help your teeth look good and don't get to much food on your plate.(lol)
And use really good toothpaste brands and remember if you're doing a project know what you're looking. And it will help your smile out too.

Neil C [last name deleted for privacy by Editor]
science fair - Columbus, Ohio


I did a similar project on which toothpaste works the best and I soaked egg shells in coffee overnight then the next day I put it in vinegar but brushing on the different toothpaste first put them in vinegar . but the results where not astonishing really you couldn't tell which one worked the best what do I do we already put on our facts and stuff on the board

Dallas T. [last name deleted for privacy by Editor]
- Youngsville , North Carolina


Hey everybody,
I am in 8th grade and I am doing the same project as all of you. I have heard so many different ways of doing this experiment. I have heard soak in vinegar. Then I heard take 3 eggs and soak them all in coffee and test three different kinds of toothpastes on them. But what I finally have decided to do is take coffee, kool-aid, and tea. Test Rembrandt toothpaste on 3 eggs sitting in a group of coffee, kool-aid, and tea. Test Colgate on 3 other eggs in the same substances and finally test whitening gel like crest whitening gel because that seems like a product a lot of people buy. I've heard the egg does not work as well with the yolk inside or hardboiled. So what I am going to do is poke two holes on the bottom of the egg and blow the yolk out. That way you still have the eggshell that represents the enamel without the stink!
Hope it works out for all of you
wish me good luck!

Kelsey H [last name deleted for privacy by Editor]
- East Petersburg, Pennsylvania


Hello Malin,
I think that you have done a great job! I am doing my report on the same thing as you except I was looking on the internet for more ideas and I found yours here. I am going to soak my eggs in grape juice and then in tooth paste and do the rest of the procedure.
P.S. Hope all went well!

Crysa W. [last name deleted for privacy by Editor]
- Vernal, Utah


Which is the better application to evaluate whitening toothpastes, brushing it on a coffee-stained hard-boiled egg as if brushing my teeth or applying some and leaving it on overnight?

Jarod P. [last name deleted for privacy by Editor]
- Coral Springs, Florida


I am doing an experiment on which toothpaste whitens your teeth best using eggs. My questions are: 1. Should I use hard-boiled eggs or eggs shells ?
2. How can I get a Teeth-Whitening Chart? I couldn't find any on Internet .
Thanks to all,

Melissa H [last name deleted for privacy by Editor]
Ibn Khaldoon School - UAE


It depends on how you are applying the toothpaste, if you are brushing it on like you're brushing your teeth then you should use hard boiled eggs. The tooth has something called enamel and so does the shell and they also both contain calcium.
Also, go to your local dentist and ask if they could lend you a tooth color model, I did this and it worked!
Good luck with your project!

Jarod P. [last name deleted for privacy by Editor]
- Coral Springs, Florida

February 5, 2012

I am doing a science fair project on the same thing. I did not use the egg. I had ceramic sample tiles used for teeth. I am putting into different sodas including Kool-aid and coffee. Let it remain for 48 hours.

Kaylynne C
- Washington DC

March 3, 2012

I am doing testing of different toothpaste brands and seeing which one is the whitest but I don't know a title for it. What should I do?

Ashlye D [last name deleted for privacy by Editor]
- Dallas, Texas USA

March , 2012

Hi, Ashlye. How about: "Experiment to determine whitening power of toothpaste without animal studies"?


Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

March 18, 2012

Hey, I did the same project. I soaked my eggs in tea and vinegar. My question is how do I graph the x and y intercepts and what are the x and y intercepts? I need to know by Wednesday and I am so confused.


lindsey W [last name deleted for privacy by Editor]
- dove canyon California usa

March 18, 2012

Hi Lindsey. You may have to read each of the following paragraphs slowly several times to understand, but --

Let's suppose you print out a map of the 48 states of the continental USA, and you draw a horizontal line through the center of it, and a vertical line through the center of it. We call the horizontal line the "x axis" and the vertical line the "y axis". The two lines will cross somewhere near Kansas City. The point where the lines cross is called "the origin", and we say that this origin or crossing point is where x=0 and y=0. Every point in the USA is some number of miles East or West of Kansas City, and some number of miles North or South of it.

The continental US is about 2700 miles wide and 1600 miles tall. So, just going by eye . . .
- Dove Canyon looks like it is, oh, about 1150 miles West of Kansas City and 300 miles South of it.
- Disneyland in Orlando, Florida looks like it is, say, 700 miles East of Kansas City and, say, 600 miles South of it.
- New York City is about 1000 miles East of Kansas City and 200 miles North of it.
- Portland, Oregon is about 1300 miles West of Kansas City and 600 miles North of it.

So we could say that the x and y value (or the x and y coordinates) of Kansas City are 0,0.
The x and y coordinates of Dove Canyon are -1150,-300.
The x and y coordinates of Orlando are 700,-600.
The x and y coordinates of New York City are 1000,200.
And the x and y coordinates of Portland are -1300, 600.

That's how graphs work. If you were to draw a straight line from Dove Canyon towards New York City, it would cross the y axis 33 miles South of Kansas City, and cross the x axis 140 miles East of Kansas City. We would say the x intercept is 140 and the y intercept is -33.

If you drew a straight line from Orlando to Dove Canyon, it would cross the y axis at about 480 miles South of Kansas City, so the y intercept is -480, but the line wouldn't cross the x-axis anywhere on your map (if you continued the line beyond Dove Canyon, it would eventually cross the x-axis somewhere about 1700 miles out in the middle of the Pacific Ocean.

Somehow you have to graph your results, whatever they were; and when you do, the line may cross the y-axis (and thus have a y intercept) and/or it may cross the x-axis (and thus have an x intercept)


Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

March 18, 2012

Hello, I'm doing a science fair project on with major toothpaste brand whitens teeth better. And I'm wondering how to write results. Any tips?

Olivia C [last name deleted for privacy by Editor]
- Belmont, California USA

March 20, 2012

Hi, Olivia. What results did you get?


Ted Mooney,
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

This public forum has 60,000 threads. If you have a question in mind which seems off topic to this thread, you might prefer to Search the Site

ADD a Q or A to THIS thread START a NEW THREADView This Week's HOT TOPICS

Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2017     -    Privacy Policy
How Google uses data when you visit this site.