Acidity and Human Teeth, 1
Running Head: ACIDITY AND HUMAN TEETH
The Effects of Acidic and Sugar Drinks on Human Teeth
Selina Chin
TAF Academy
Acidity and Human Teeth, 2
Introduction
Everyone knows that they need a good diet in order to stay healthy, but do they know the
reason behind it? One important reason that people overlook is maintaining the health of their
mouth, teeth, and gums. When maintaining the teeth and gums follow the dentist directions; plus,
doing the basic of brushing the teeth every day and flossing could help prevent infections and
damage to the enamel. Chewing food is the first step of the digestion process. I plan to identify
which substances are most harmful to the tooth, then using what I found, remind people, and show
them evidence. It could lower the incidence of tooth decay and gum disease. In this project, I am
investigating the effects of drink sugar content and acidity on teeth. My research question is What
type of drinks affects the enamel of the human teeth? How can this information interfere with
people’s behavior? By conducting this experiment, it could raise awareness for people do not
realize how certain drinks affect the tooth’s enamel. Another thing is that the cost of dental
insurance has gone up, and it is hard for people to get it now. Some low income people do not visit
the dentist, and their teeth get worse. Then they have to pay more than the regular dental check-up
to fix the damage.
Acid erosion is when acidic drinks, like soda, or foods, like lemons, damage the enamel of
the tooth. (Tooth Enamel: Erosion and restoration, 2014) Key factors that determine acid’s impact
on enamel are pH levels in drinks, duration, and eating disorder. The tooth enamel is mostly made
up of hydroxyapatite (HA), CA10 (PO4) (OH)2, it also contains carbonate and fluoride. The amount
varies from person to person. (Ren, 2011). When looking at certain drinks and measuring their pH
levels, the lower the pH level is, the more acidic they are. pH levels are levels of a solution that
measures the hydrogen-ion concentrations. Plus, when the acidic food or drink is exposed in your
mouth for a long period time, it gives it more time to attack the tooth enamel. In addition to drinks,
Acidity and Human Teeth, 3
acid damage to enamel can occur in individuals who have bulimia. Bulimia is a condition in which
people have an eating disorder and start vomiting or have indigestion, which is regurgitation or
gastric reflux.
The prices of dental care costs way too much. For two new crows, a person had to pay
3,442 dollars. There was another situation that a person went to two different dentists and got two
different opinions on what their mouth needed. (Butler, 2011). The reason why dentist cost so
much is that dentist have to pay for their office space, taxes, supplies, business insurance, staff and
technology. They also must have the high quality lab to help them make crowns and dentures for
their patients. There are about 85 million Americans that are lacking dental. (Pollack, 2013).
Because of this, there are more problems and it is causing school absence, and missed work days.
More than half of low income children are without health insurances. Studies have shown that
children from low-income families (those with incomes below 200% of the federal poverty level)
are less likely to receive dental care and more likely to have unmet dental needs than children from
higher income families. (Kenney, 2005).
On May 3rd, 2012, Mikaela Conely wrote an article for ABC news about energy/ sports
drinks destroying teeth. The article reported that the acid in the energy and sports drinks do some
irreversible damage. If this happens, it can cause the enamel to become sensitive to touch and
temperature changes, and more vulnerable to cavities and decay. They tested the impact of many
other drinks as well, checking the pH levels on 13 different sports drinks and nine energy drinks.
To test the effect on enamel, the researchers submerged human teeth enamel in each beverage for
15 minutes. They then submerged the enamel in a sample of artificial saliva for two hours, and
repeated this procedure 4 times a day for 5 days and measured damage to the enamel over time.
Acidity and Human Teeth, 4
Not many people know that energy drinks and other sweet, acidic drinks can harm human tooth
enamel.
Variables
Citrus fruits like lemons are rich with vitamin C and other great nutrients. However,
when it comes to teeth, they are highly acidic and can erode the teeth enamel if consumed
constantly. In a study by Bassiouny Ma, Yang J. and Kuroda S, the authors monitored the
changes of topography, morphology, and radiographic profiles of human teeth that was exposing
to citrus fruit juice. “The results indicated that orange juice specimens demonstrated the mildest
changes, while lemon juice specimens displayed the most severe damage to the coronal segments
of the teeth. This damage manifested as loss of cusp height, cervical enamel, and coronal radius,
as well as reduction of enamel cap height” (Bassiouny, M., Yang, J., & Kuroda, S ,2008). If they
continued to submerge the acidic fluids on the tooth, the enamel loss will continually progress.
Coffee is great for waking up to in the morning. It helps people get through the day and
wake up. However, not many people know that coffee can really affect the enamel of the tooth. The
sugar you add to the coffee eats away the enamel of the tooth. Coffee also can stain the tooth. In
the article by Bazzi, Bindo, Rached, Mazur, Vieira, and de Souza, the effect of at-home bleaching
and tooth brushing on removal of coffee and cigarette smoke stains and color stability of enamel,
they used a colorimeter to measure the color of the enamel surface. In the end, the results both
smoking and coffee stains had significant reduction; however, the restaining potential was greater
for coffee than cigarette smoke. (Bazzi, J., Bindo, M., & Mazur, R., 2012).
Soda is a popular drink that many Americans drink frequently. Its available almost
everywhere we go. The average American consumes 44 gallons of soda per year (Trotter, 2013).
The number has decreased since 1998, the number was even higher. Even though, the number has
Acidity and Human Teeth, 5
gone down from 1998 to 2014, the downhill trend should continue. The average American drank
about 58 gallons per year. In the article, Dental erosion and severe tooth decay related to soft
drinks: a case report and literature review, they did a study based off a 25 year old man that had
been drinking cola for more than seven years, and had very poor oral hygiene. He had severe worn
out teeth, and there were many decays in the incisors and the canines. “Finally, the history and the
symptoms of this patient confirmed the complex diagnosis of dental erosion and dental caries”
(Zhejiang, 2009). Drinking soda can cause a lot of potential health problems. The erosive potential
of drinks is mainly represented by their pH. The patient’s tooth was hurting the pulp cavity of the
tooth; it had a lot of grey debris.
Milk has many sources of nutrients for a human body. It has vitamin D, calcium,
magnesium, and potassium. “Milk is better than water at preventing the bacteria in plaque from
producing acids when they are feasting on sugar, researchers said” (Macrae, 2013). However,
milk its self is also acidic. Not as much as soda, coffee, and lemon juice, but still slightly acidic.
Depending on what milk, it is very close of having a pH level of 7.0, which is neutral.
Research Question:
What type of drinks affects the enamel of the human teeth? How can this information interfere
with people’s behavior?
Hypothesis:
I hypothesis that lemon juice will affect the enamel the most, and then soda, coffee, milk, and
then the regular water. I think this because based on my research lemon juice has a pH level
around a 2. Then the classic Coca-cola has a pH level around 2.5 – 4.2. When people drink straight
black coffee, the pH level in that is around a 5 on the scale. Finally, milk has a pH level around 6.5
to 6.7.
Materials-
Acidity and Human Teeth, 6
Materials
How is it being obtained?
Teeth or egg shells (6 or more)
Home/Parents
Scale that reads 0.001 g
Borrow from school
Artificial saliva
Order online
Pipets
Borrow from school
Graduated cylinder
Borrow from school
Timer
Personal Phone timer
Gloves
Home
Baby food jars (2.5 oz)
Buy from store/ Use from last year
Microscope
Borrow from school
Beaker
Borrow from school
Distilled Water
Buy from store
2% Milk
Buy from store
Lemon Juice
Buy from store
Coffee
Buy from store
Cola
Buy from store
pH level strips
Borrow from school
Procedure1.
2.
3.
4.
5.
6.
7.
8.
Collecting all the materials that will be needed
Gather teeth or something that will represent the tooth like the shells of eggs
Put one tooth in different baby food jars
Label baby food jars of each of the drinks
Calibrate between egg shells and teeth.
Soak the tooth in artificial saliva (25 mL) for 1 hour.
Record results (Ex. Write the weight, scale color, picture, and surface)
Soak teeth in Cola (25 mL) for 10 minutes
Acidity and Human Teeth, 7
9. Record results (Ex. Write the weight, scale color, picture, and surface)
10. Soak a different tooth in artificial saliva (25 mL) 1 hour.
11. Record results (Ex. Write the weight, scale color, picture, and surface)
12. Soak teeth in Milk (25 mL) for 10 minutes
13. Record results (Ex. Write the weight, scale color, picture, and surface)
14. Soak a different tooth in artificial saliva (25 mL) 1 hour.
15. Record results (Ex. Write the weight, scale color, picture, and surface)
16. Soak teeth in Lemon juice (25 mL) for 10 minutes
17. Record results (Ex. Write the weight, scale color, picture, and surface)
18. Soak a different tooth in artificial saliva(25 mL) 1 hour.
19. Record results (Ex. Write the weight, scale color, picture, and surface)
20. Soak teeth in Coffee (25 mL) for 10 minutes
21. Record results (Ex. Write the weight, scale color, picture, and surface)
22. Soak a different tooth in artificial saliva (25 mL) 1 hour.
23. Record results (Ex. Write the weight, scale color, picture, and surface)
24. Soak teeth in Water (25 mL) for 10 minutes
25. Record results (Ex. Write the weight, scale color, picture, and surface)
26. Soak a different tooth in artificial saliva (25 mL) 1 hour.
27. Record results (Ex. Write the weight, scale color, picture, and surface)
28. Do steps 4 – 24 again for trial 2
VariablesIV: Coffee, Milk, Water, and Cola
IV levels: Milk, Water, Cola pH levels
DV: The color of the tooth, the weight, the textures
Repeated trials: 2
Constants (Controlled Variables): Tooth weight/Egg shells, amount of liquid, time of exposure,
amount of artificial saliva.
Control Group: One tooth or egg that is expose only to artificial saliva
Dependent variable –
Since, I do not have all the tools as a scientist; I have to be creative on how I can measure the
enamel of the human teeth. It is difficult to see it under the microscope, but it is the only
resource I have available with me. When looking at the color, I will take picture of the before
and after it has been exposed to the liquids, seeing if the color has changed on the outer
Acidity and Human Teeth, 8
surface. The weight will be looked at by comparing the original weight, if the weight is
decreased; it could be that some parts of the tooth have eroded away. When looking at the
textures on the surface, I will use the tools that dentist uses to see which parts are rough and
from that, then from scaling it from a 1-10, 1 being smooth and 10 being rough.
Trial 1 : First exposure
Weight (g)
Color
Texture
Picture (Before/After)
Cola
Milk
Coffee
Water
Trial 2 : Second exposure
Weight (g)
Color
Texture
Picture (Before/After)
Cola
Milk
Coffee
Water
Trial 3 : Third exposure
Weight (g)
Cola
Milk
Coffee
Water
Color
Texture
Picture (Before/After)
Acidity and Human Teeth, 9
The other data that I will collect are pictures under a microscope of the tooth or egg
shell that was exposed to each liquid. These pictures will show the actual textures that I found
and the before and after of each liquid to see if there was any difference. The calculations that I
will be performing with quantitative data is finding out the difference between the weight of
each tooth before it was exposed to each liquid and after it was expose. Then I will find the
difference from each exposure, like from exposure one to exposure two, and from exposure
two to exposure three. Then I will find the total average of how much the weight of the tooth
increase or decrease. I will use a line graph to chart the weight and see if there is a pattern for
each liquid.
Acidity and Human Teeth, 10
References
Bassiouny, M., Yang, J., & Kuroda, S. (2008, April). Topographic and radiographic profile
assessment of dental erosion. Part II: Effect of citrus fruit juices on human
dentition. Retrieved December 20, 2014, from
http://www.ncbi.nlm.nih.gov/pubmed/18348369
Bazzi, J., & Rached, R. (2012, May 1). The effect of at-home bleaching and tooth brushing on
removal of coffee and cigarette smoke stains and color stability of enamel.
Retrieved December 20, 2014, from
http://www.ncbi.nlm.nih.gov/pubmed/22547725
Buttler, S. (2011, June 10). Why Your Dentist Costs So Much. Retrieved January 6, 2015, from
http://www.cbsnews.com/news/why-your-dentist-costs-so-much/
Conley, M. (2012, May 3). Energy, Sports Drinks Destroy Teeth, Says Study. Retrieved
December 20, 2014, from http://abcnews.go.com/blogs/health/2012/05/03/energysports-drinks-destroy-teeth-says-study/
Dawes, C. (2003). What Is the Critical pH and Why Does a Tooth Dissolve in Acid? Journal of
the Canadian Dental Association, 69(11), 722-724. Retrieved December 19, 2014,
from https://www.cda-adc.ca/jcda/vol-69/issue-11/722.pdf
DEVLIN, H., BASSIOUNY, M. A. and BOSTON, D. (2006), Hardness of enamel exposed to
Coca-Cola® and artificial saliva. Journal of Oral Rehabilitation, 33: 26–30.
doi: 10.1111/j.1365-2842.2006.01533.x
Kenney, G., McFeeters, J., & Yee, J. (2005, August 1). Preventive Dental Care and Unmet
Dental Needs Among Low-Income Children. Retrieved January 9, 2015, from
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1449367/
Acidity and Human Teeth, 11
Neporent, L. (2012, September 17). Dental Care Has Decayed for Low Income Families.
Retrieved January 9, 2015, from http://abcnews.go.com/Health/dental-caredecayed-low-income-families/story?id=17230584
Pollack, H. (2013, August 8). 85 million Americans lack dental coverage. Fixing that requires
more than just money. Retrieved January 6, 2015, from
http://www.washingtonpost.com/blogs/wonkblog/wp/2013/08/08/85-millionamericans-lack-dental-coverage-fixing-that-requires-more-than-just-money/
Rattue, P. (2012, February 17). Eating Disorders Cause Severe Dental Erosion. Retrieved
December 20, 2014, from http://www.medicalnewstoday.com/articles/241857.php
Ren, Y. (2011, April). Dental Erosion: Etiology, Diagnosis and Prevention. Retrieved December
20, 2014, from http://www.rdhmag.com/etc/medialib/new-lib/rdh/siteimages/volume-31/issue-8/1108RDH075-085.pdf
Rini, J. (2014, September 1). Low income? Dental care hard to come by. Retrieved January 9,
2015, from http://www.delawareonline.com/story/news/health/2014/09/01/lowincome-dental-care-hard-come/14760659/
Sutnick, M. R. (2003). Dentistry. In S. H. Katz (Ed.), Encyclopedia of Food and Culture (Vol. 1,
pp. 512-513). New York: Charles Scribner's Sons. Retrieved from
http://go.galegroup.com/ps/i.do?id=GALE%7CCX3403400177&v=2.1&u=kcls&
it=r&p=GVRL&sw=w&asid=2881f09a31913d3a7d15fcd549244985
Tooth Enamel: Erosion and Restoration. (2014). Retrieved December 20, 2014, from
http://www.webmd.com/oral-health/guide/tooth-enamel-erosion-restoration
Acidity and Human Teeth, 12
Zhejiang, J. (2009, May). Dental erosion and severe tooth decay related to soft drinks: A case
report and literature review. Retrieved December 20, 2014, from
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2676420