The Effect of Tooth Cleaners on Stains
Picture of the student researcher

Researched by Emily H.


The purpose of this experiment was to determine the cleaning ability of tooth cleaners on stains. 

I became interested in this idea when I started seeing lots of tooth cleaning ads on the television. They all claimed that they were the best. So I wanted to know which one was really the best. 

The information gained from this experiment will help consumers choose the best tooth cleaner for their money. 


My hypothesis was that Rembrandt Intense Stain Removal would work the best because it had the most hydrated silica in it. 

I base my hypothesis on a conversation with Carol who works for Colgate. She said, " Hydrated silica was in their # 1 whitening toothpaste called Colgate Sparkling White." So I think the brand with the most hydrated silica will be the brand that works the best. 

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The constants in this study were:

  • Amount of stain that teeth are soaked in:
  • Amount of time soaked in stain: 5 hours
  • Amount of toothpaste put on teeth:
  • Brand of Toothbrush: Target Brand
  • Amount of Teeth:
  • Amount of Strokes: 50 strokes per tooth
  • Size of Dixie cups:

The manipulated variable was the kinds of toothpaste’s used to whiten the teeth, (Crest Dual Action Whitening, Colgate Sparkling White Tarter Control, Aqua Fresh Advanced Freshness, Rembrandt Intense Stain Removal, Sensodyne Extra Whitening, and Advanced White Baking Soda and Peroxide). 

The responding variable was the amount of stain that was removed from the teeth after they were stained and then cleaned with various different tooth cleaners. 

To measure the responding variable I used a color guide from the dentist office to measure the change in shade (whiteness).

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 tube of Crest Dual Action Whitening
1 tube of Colgate Sparkling White Tarter Control
1 tube of Aqua Fresh Advanced Freshness
1 tube of Rembrandt Intense Stain Removal
1 tube of Sensodyne Extra Whitening
1 tube of Advanced White Baking Soda and Peroxide
 Toothbrush’s (Target Brand)
18  Dixie cups
1 Shade Guide
18 Fake teeth
1 Roll of wax paper
6 50 ml. cups of Folgers Coffee
6 50 ml. cups of Welch’s Grape Juice
6 50 ml. cups of Coca-Cola
Pair of latex gloves
Roll of tape
1 Kitchen towel

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1. Gather Materials
2. Label toothbrushes by toothpastes
a.) Crest dual action whitening
b.) Colgate sparkling white tarter control
c.) Aqua fresh advanced freshness
d.) Rembrandt intense stain removal
e.) Sensodyne extra whitening
f.) Advanced white baking soda and peroxide 
3. Label Dixie cups
     a.) "c" for coffee 
     b.) "g" for grape juice
     c.) "cola" for Coca-Cola
4. Brew coffee
5. Poor all 3 drinks into 6 Dixie cups each (50 ml. each)
6. Compare teeth to shade guide and record
7. Put one tooth into each Dixie cup for five hours
8. Tape wax paper to counter
9. Divide wax paper into 3 sections
10. Label wax paper 
a.) coffee 
b.) grape juice
c.) coca- cola
11. Sub divide each section and label for each toothpaste
12.  Put on latex gloves and take teeth out of the Dixie cups
13.  Place on wax paper in there proper section
14. Compare teeth to shade guide and record
15. Take Crest dual action whitening 
16. Squirt 1/8 of a tea spoon and scrape it onto the toothbrush labeled Crest
17. Then brush the tooth (with latex gloves on) labeled coffee with Crest using 100 strokes 
18. Rinse the tooth, latex gloves, and the measuring spoon
19. Then dry off the measuring spoon, tooth, and the latex gloves
20. Repeat steps 14-19 with all other toothpastes
21. Repeat steps 14-20 with Grape Juice and Coca-Cola
22. Finally compare teeth to shade guide and record

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The original purpose of this experiment was to determine the cleaning ability of tooth cleaners on stains. 

The results of the experiment were the Crest Dual Action Whitening proved to whiten the best on coffee, grape juice, and coca-cola. Sensodyne did the second best on all three stains. Then the third best were Aqua Fresh and Rembrandt. The last ones were Colgate and Advance White Baking Soda and Peroxide. 

See data and graphs


My hypothesis was that Rembrandt Intense Stain Removal would work the best. 

The results indicate that this hypothesis should be rejected because the Crest Dual Action Whitening worked the best on all three stains and the Rembrandt toothpaste didn’t was third. 

Because of the results of this experiment, I wonder if the longer you were to brush the tooth the more of the stain would come off? Also, I wonder if the more expensive toothpaste works better?

If I were to conduct this project again I would use more brands of toothpaste so that I could have bigger differences in my results. I would find a much better way to measure the toothpaste. I would use different stains that stained the teeth a lot more. I think that I made a mistake by not choosing to use a colorimeter instead of a shade guide. The shade guide was not a good choice because the purple did not show up on it and was more difficult to tell the true color of the tooth. I would have taken more pictures during the experiment and I would have observed the teeth while they were soaking in the stain so that I wouldn’t have missed anything.  I would also start out with the teeth at the same whiteness. I would also use more teeth per group.

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Teeth are bonelike structures in the upper and lower jaws of human beings and many kinds of animals. Teeth are the hardest part of the human body. They are also the first step to the digestion process and they make your appearance much more appealing. 

Parts of a Tooth

 Teeth are made up of four tissues. They are, the enamel, cementum, dentin, and pulp. From the outside to the inside of the tooth the tissues go in this order. The enamel overlies the dentin of the crown, the cementum overlies the dentin of the root, and the dentin overlies the pulp. 
Enamel is the hardest substance of the tooth, and your whole body. It is a clear outer layer of the tooth underneath the crown. The enamel is 0.16 cm. thick or about 0.06 in. thick. Since the enamel is this thick it protects the inner layers from harmful bacteria. The enamel also resists the temperature changes from hot to cold.
The cementum is the thin layer of bony tissue that covers the dentin at the root. Normally the cementum and the enamel connect where the root ends and the crown begins. Cementum is just about as hard as bone. The surface of the tooth wears away and then the tooth grows further out of the socket exposing the root. This makes the tooth more sensitive to hot and cold.
The dentin is a hard substance that is yellow. This tissue surrounds the pulp and protects it. Dentin is mainly mineral salts and water but it still consists of living cells. The tooth is mainly made up of dentin. Dentin is harder than bone.
Pulp is the innermost layer of the tooth. It consists of blood vessels, connective tissues, and nerves. The blood vessels carry oxygen and nutrients to the nerves in the tooth and the nerves transmit pain sensations to the brain. The pulp has two parts. They are the pulp chamber and the root canal.
Types of Teeth
 There are two different types of teeth. The first teeth are the deciduous teeth that appear around 7 1/2 months in babies. The second are the permanent teeth that appear around 2 years of age. They both have pretty much the same basic form. 
 The deciduous teeth start to form inside the jaw before a baby is born. They start as ovals and gradually form into teeth. At about 7 1/2 to 9 months teeth start to erupt out of the gums. This erupting is also called teething. At about 2 years old all of the deciduous teeth are present. After about three years of age the roots of the teeth are completely dissolved. 
There are 20 deciduous teeth total and 10 in each jaw. Each jaw has three different types of teeth. The different teeth are the incisors, canines, and molars. There are 4 incisors, 2 canines, and 3 molars in each upper and lower jaw. Incisors and Canines are used to bite into food. The Molars are used for chewing and grinding food. 
The permanent teeth form near the roots of the deciduous teeth. After the deciduous teeth’s roots are dissolved the permanent teeth push up and the deciduous teeth fall out of the jaw. This happens at about 5 to 7 years of age. Some of the last permanent teeth come in at about 17 to 21 years of age.
There are 32 permanent teeth in the upper and lower jaws, with 16 teeth in each jaw.  They consist of four different kinds of teeth. They are the incisors, the canines, the premolars, and the molars. There are 4 incisors, 2 canines, 4 premolars, and 6 molars in each jaw. The incisors and the canines are used for biting into food. Also the premolars and molars are used for grinding and chewing food. 

Diseases that Affect Teeth

 There are two kinds of periodical diseases. They are gingivitis and periodontitis, which is gingivitis when it is not taken care of in time. These diseases are caused by build-up of plaque and calculus that irritate the gums. This makes the gums inflamed and they may bleed easily if poked or prodded.  Gums may also become irritated by breathing out of the mouth, smoking or chewing tobacco, brushing improperly, or wearing too big or too small of dentures. To prevent getting these diseases floss daily. Also a dentist can treat them by removing unwanted plaque and calculus. 
 Another type of disease is dental decay or caries. This disease is the most common. Most of the people under 35 who lose their teeth do so because of dental decay. Dental decay happens when saliva sticks to teeth. Then the plaque and food stick to the tooth. The food creates an acid that dissolves into the enamel. This is when a cavity is formed. If the cavity is not filled the acid dissolves into the dentin and then into the pulp. Once it reaches the pulp it starts a toothache. There are several ways that dentists can treat dental decay. They are filling a cavity, performing a root canal, crowning a tooth, and removing and replacing teeth. 
 Also there is a disease called malocclusion. This disease is when in the teeth in the upper and lower jaws grow in improperly placed. There are three main cases of malocclusion. They are overbite, underbite, and crowding. Overbite is when the upper jaw extends over the lower jaw. This is better known as buckteeth. Underbite is when the lower jaw extends out further than the upper jaw. The most common case of malocclusion is crowding. Most of the cases of malocclusion can be handled with braces. 
 The last disease is oral cancer. Oral cancer is not very common, but 8,000 people die from it a year. This disease destroys the tissues in the mouth and can spread throughout the body. Scientists are not sure what causes oral cancer, but the factors include drinking lots of alcoholic beverages, smoking, and chewing tobacco. This disease can be treated with drugs, radiation, and surgery. 

Good Hygiene Habits

Good hygiene habits are flossing your teeth, and brushing your teeth with toothpaste and a toothbrush. Toothbrushes are very important because they clean plaque and food particles from the surfaces of your teeth. This is important so that you do not end up with cavities and gingivitis. Flossing is important because it cleans plaque and food particles from between the teeth and the gums. The last good hygiene habit is dental check-ups, which are important, especially if you have not been brushing or flossing. If you have a cavity they can find it before it gets too bad and if you have gingivitis they can treat it before it turns into periodontitis. 

Whitening Toothpaste

There are many different types of whitening toothpaste but they all have something in common, silica and hydrated silica. These are in whitening toothpaste’s because hydrated silica and silica are basically sand. They use them to make cement. Since these are so sharp and rough they not only take away the stain but they also scrape away a tiny thickness of your teeth too.


Flossing is very important to your dental hygiene because without flossing your gums would become inflamed and bleed. Flossing is when you take a string and move it up and down while it is in between two of your teeth. 


 Dentistry is the science of diagnosing, treating, and preventing diseases of the teeth, jaw, and surrounding tissues of the mouth. Dentists care for their patients by recognizing, correcting, and preventing problems of the teeth and tissues in the mouth. One important service is correcting dental decay. They also have to fill cavities and sometimes they even have to remove teeth from the mouth.

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Amethyst Galleries, Inc. "The Gemstone, Opal." The Mineral Gallery. January 23, 2002

Gaskin, John. "Teeth" World Book. 1998 ed. CD-ROM. Wold Book Inc., 1998

Knapp, Brian. Chlorine United States: Atlantic Europe Publishing Company, 1996 5 and 37

Martin, Chris. "Teeth." Encarta Reference Suite. 2000 ed. CD-ROM

Ward, Brian "Teeth" World Book Encyclopedia. 1995

Wortel, John "Dentistry." World Book Encyclopedia. 2000


I would like to thank the following people. Without their help my project would have not been possible.
* My mom and dad for transporting me to all after school SOAR classes. 
* My dad for helping me with stay on task while working on my experiment. 
* My mom for helping with searching for information, letting me stay up and work on my report, and helping me remember dates for my log book. 
* The dentist for lending me their fake teeth and their shade guide. 
* My friends Rachel and Cody for giving me tips on how to make my project better. 
* Mrs. Helms for helping me with mess ups on my report and my board. 
* Mr. Newkirk for lending me two cylinders, correcting my report and helping me create my graphs.

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