Science Buddies: "Ask an Expert"

What effect does the drinking of milk, orange juice, and Pepsi have on the health of teeth?

Does drinking milk, orange juice, and Pepsi effect the strength of teeth?

Do over the counter whitening strips help whiten teeth?

Can you recommend four different whitening strips to use in my experiment?

Do over the counter whitening strips effect the strength of teeth?

I've judged a few science fairs where this experiment is done. Usually not very well, typically just examples of stained teeth, by cola or something.

Adding the "whitener" to the experiment could possibly help. You would need to find a way to improve on the "example" model. The whitening strips are kind of expensive.

How would you measure the "strength" of teeth exposed to different substances?

Are you doing all of the topic questions or just one? What do you need help on? You only listed out a couple topic questions without saying what you needed help on. These sound like interesting topic questions, so please clarify!

Hi Paul,

After looking at your questions, I realized you are doing 8 different experiments.

What I would suggest is to research on all of these things you are interested in, and choose one thing.

https://www.sciencebuddies.org/mentorin ... thod.shtml - this website will help explain everything on how to focus all of your interests into one complete project.

Hope this helps,
Sareena

Hi Paul,

Here are some suggestions for your project:

The problem with teeth projects is that it's difficult to design a quantitative experiment, and it's difficult to obtain teeth. To solve these problems, you can use chicken bones (or other bones) because these composed of calcium phosphate and are chemically identical to teeth (except for the enamel coating). You can dry the bones and weigh them with a scale that is accurate to 0.01 gram. If you soak them in the solutions you want to test, then dry and weigh them again, you can measure a difference in weight due to the test treatment. If you are very careful, you will obtain data that you can graph.

There is a product called hydroxyapatite that is used by dentists and surgeons for bone and dental replacement, and by chemists in research laboratories that is also composed of calcium phosphate. It's a white powder. If you can obtain this product, you could use it as a tooth substitute.

The whitening project is more difficult to quantitate, but dentists do have color charts that can be used to evaluate the effectiveness of teeth whitening. For this project you would have to stain the teeth/chicken bones/hydroxyapatite and then do the whitening treatment and then evaluate the results based on color change.

I think that a project with results in grams would be a better than one with results in relative whiteness, but you should pick the project you are most interested in doing.

Good luck!

Donna Hardy

November 27, 2005
Dear Experts,
I want to thank all of you for taking the time to respond to me and for giving me your advice, suggestions, and help. I am hoping that you all will continue to stay with me as I continue to work on my experiment. I am sorry for the delay in my response, my father lost the sight in his right eye, detached retina, shortly after I posted and this took me away from my focus on the experiment. Each of you has stated some good observations, which, unfortunately I have found to be true but with some of the alternative suggestions, I am hoping to salvage this experiment.

Background: When I first thought of this experiment, my Dad and I discussed many of the issues each of you has brought up. We went to our family dentist back in Sept. and he assured us that it should not be a problem securing the teeth. Well, as with life, curve balls are thrown at you and I am learning, at age 13, that I have to adjust because I refuse to concede.

Status: 1. Yes, there has been a problem getting teeth. After getting 6 teeth (4 from 1 person & 2 from another), I am now having difficulty getting the original 12 that I thought I would have. (The people having there teeth pulled are keeping them, or they are breaking up, as they are being removed) Anyway, I might have to consider the chicken bone idea from donnahardy2. 2. Mr. Lewandowski, the pliers instrument that I was designing to measure the newton strength, crush a pebble, therefore, I had to come up with another instrument to test strength. My mechanic friend suggested we use a water type instrument. (Using 2 2X4's, spring-loaded at the side, place the tooth under the boards and a bucket on top. Add water to the bucket until the tooth cracks, measure the weight of the water, and convert that into newtons. 3. In my experiment, I have stated that I will soak 1 tooth each in


3. In my experiment, I have stated that I will soak 1 tooth each in 50 mm of Pepsi, orange juice, and milk for1 hour everyday for 3 weeks. I am keeping 1 tooth out as my control. 4. I will put all of the teeth in a jeweler ultrasonic cleaning machine, with a toothpaste to clean them.

I am hoping to get at least 2 more teeth because I realize that I need to do 2 types of experiments. A) Testing the strength of the teeth without the whitening strips and B) Once the teeth are dry I will apply the 3 kinds of whitening systems to 3 of the 4 sides of the teeth. All of the whitening systems have similar ingredients. One system is painted on, and strips apply the other systems for 30 minutes. I have 2 strip methods, CVS for $10 and Crest for $30. I want to see the effect of all 3 systems when applied. I will take digital pictures of each tooth before the experiment and then after the designated time allotted for each day. For A) I will document daily observations and take pictures every 4 days. B) The whitening system lasts for 7 days. I will take pictures every 2 days.

Thank you for your help. I hope you each continue to respond. I look forward to your expertise.

I hope you each had a nice Thanksgiving.
Sincerely,
Paul

Hi Paul,

Condolences to your dad and your family: I hope everything is going well.

It sounds that you've given your experiment some thought and it looks like your approach is right on the dot! Make sure you keep a watchful mind on your controls and your dependent and independent variabes - mainly because you are trying to test so many different things.

Regards,
Sareena

Hi Paul,

I'm really sorry to hear about your Dad. I hope he is feeling better, and adapting to his disability. I know a family health emergency can affect everyone, but I'm glad you are able to think about your schoolwork again.

Here are some comments that hope will be helpful for your science fair project:

1. You are still planning to do too many experiments. In a science fair project, it is better to do just one experiment very well. You need a main purpose and your experiment should answer a question. Your general topic is very good, but you need to focus on just one thing. What do you want to accomplish? Do you want to study the effects of different drinks, or work on teeth whitening?

2. Add a couple of more samples: You seem to have picked drinks that teenagers consume. Why don't you consider adding water, red Gatorade, and perhaps a caramel frappacino from Starbucks? Do teenagers drink coffee or tea?

3. Time. Instead of dipping the teeth in the drinks for 1 hour a day for a week, just go ahead and soak them for 3-4 days straight. You can keep the sample in the refrigerator to keep the bacteria from growing too fast, or just keep everything at room temperature. If the samples start to ferment, it will be like plaque growing on your teeth.

4. Samples. Go ahead and try to get more teeth, but use chicken bones as a back up. You might be able to get teeth from a veterinarian if you can't get any more from your dentist. 6 teeth are not enough for a good experiment. Using either 18 teeth, or 6 teeth and 12 chicken bones (samples run in triplicate) would be much better.

5. Experiment. If you decide your purpose is to measure the effect of the drinks on tooth strength, then the water instrument, which would measure results in newtons, would make an excellent project.

6. Bone chemistry: Teeth are made of fluoroapatite, which is calcium phosphate and fluoride with an enamel coating. Calcium phosphate will dissolve in acid, so you might predict that exposure of the more acidic drinks will cause loss of bone strength. Teeth whitening is based on bleaching of impurities that have absorbed to the teeth, and this process is based on oxidation and does not dissolve the tooth itself. So, you might predict that teeth whitening will not affect tooth strength.

7. Additions to your experiment. Since you want to investigate one topic thoroughly, you might want to measure the pH of your drink samples and also weigh the dried bones in addition to measuring the strength in newtons.

8. Plan your display now. It's not too early to make an outline of your final presentation. How will you communicate your results to the judges? How will you graph your results? Will you need to take pictures? If you plan the details of your display now, it will help you plan what you need to do.

Let us know if you have any questions.

Donna Hardy

Hi Paul,

Sorry about your Dad. It sounds like you are handling very well.

Please read what the other experts have read. They are right. I have judged science fairs in the past and the biggest problem with experiments like this is that comparing which is better (in this case whiter) is fairly subjective. You need to design an experiment so that you will get an objective answer and your results will be clear to everyone.

Good luck and keep up the good thinking process.
Genetha

Hi Paul,
you might save some money by using regular hydrogen peroxide, to whiten the teeth. Hydrogen peroxide seems to be the main ingredient in the whitening solutions but is much less expensive. The main difference being that the concentration of the bottled stuff might be a bit less than what is in the whitening solutions, though I"m not sure about this.

Another source for hydrogen peroxide would be a pool supply store. The stuff is used in the "shock" treatment of pools, this may be much more concentrated and need some special handling, be careful. By knowing the initial concentration you can dilute it down to whatever you want.



Jim

Dec. 9, 2005
Dear Experts,
I looked tonight and got your comments. Usually I get a message from Science Buddies but I did not. Thank you for your comments. I need to have everything completed by January 14, 2005; the experiment, research paper, analysis, pictures, data collection, charts, etc. I now have 9 teeth. I will check into dogteeth and I am looking at the chicken bone idea. I continue to look forward to your suggestions. For pictures, I was thinking of standing them up on a black background? I will check back in a couple of days. I had decided to take the pH of each substance, thank you for the reminder.
Thank you,
Paul

12-09-05 part 2
Dear Experts,
Thank you all for your kind words and thoughts for my Dad and family. Each of you are truly caring people and your friends and families are lucky to have you in their lives. I know that I feel lucky to have this relationship. You are very much appreciated.
Sincerely,
Paul

Dear Paul,

Congratulations on finding the teeth you need to continue your project.

I've learned from experience: Start your data analysis weeks before your project. I would advise to create a timeline for the completion of your project, keeping in mind to leave ample space for data analysis and setting up your board.

You have got about a month till your project is due. Think about how much data you will be collecting from your experiment(s) and all that you have to analyze. Your list is quite long, so work with your constraints!

I hope your father's recovery is going or went smoothly.

Good luck!

Sincerely,
Sareena

This is Paul with the heath of teeth project.
Thank you Sareena for asking about my Dad. He has an extensive recuperation period ahead of him. My experiment deadline has been extended to January 16th. I changed the experiment a little. I looked at everyones suggestions and redesigned my experiment and I am concentrating my experiment on the quanitative aspects of the experiment. I weighed each tooth, using a metric scale. I have 9 teeth. I kept one for the control, the other eight teeth each have their own container. I an using 4 different liquids to soak the teeth in, I added coffee. I also am soaking the teeth for a longer period of time, before removing them , making observation and pictures. I am making sure that al documentation is metric and is quantatative.
Any further suggestions are welcomed. I am still proceeding with the tooth whitening comparison on 4 of the 8 teeth, I have actual ceramic teeth that have shades where I have taken them and put them next to each tooth that are imbedded onto a piece of styrofoam.
Thank you and keep your inputs coming,
Paul

Hi Paul,

I'm glad you were able to get some more teeth and that you are proceeding with the project. You've planned your project well, so go ahead and start on it as soon as possible so you'll have time to write up the project.

Please do let us know about your results.

Donna Hardy