We predict Crest Plus extra whitening with tartar protection will remove stains the best because it claims to remove 99% of bacteria. We think getting rid of bacteria will help get rid of stains.

• Did you know toothpaste was created in ancient Egypt around 5000 BC? Ancient Egyptians used their fingers or a cloth to scrub their teeth.
• The way ancient Egyptians made their very own toothpaste is that they had lots of powders. Some of the most popular powders are crushed bones, ground charcoal, crushed oyster shells and ash.            
• Toothpaste began to shift in the 1800s. 
• In 1824, Dr. Peabody added soap to improve cleaning power
• All of the biggest toothpaste changes started with Colgate in 1873. 

• It brought mass production into homes as soap was phased out and was replaced by sodium, lauryl sulphate.

• Did you know that there is bacteria in your mouth that never stops working? Between meals they produce acids that will eat away your enamel and settle along the gumline

• Fluoride toothpaste will strengthen your enamel and abrasive will sweep away plaque

Fluoride and enamel protection

• Tooth enamel is the protective outer covering of a tooth. It shields to tooth crown (the part you can see) and the layers underneath.
• Enamel is durable – harder than bones even! But it can break down over time from: plaque, acids from foods you eat, and daily wear and tear.
• Enamel protects the tooth from decay (cavities)
• Brushing teeth every day protects the enamel. Toothpaste with fluoride helps ‘remineralize’ the enamel
• Fluoride helps prevent tooth decay by making teeth more resistant to acids made by plaque.
• This helps teeth be more resistant to decay and can even reverse some decay that has already started

How does toothpaste stop tooth decay from happening and keep teeth healthy?

• it makes a little shield from bacteria
• Toothpaste can help the teeth be stronger and more resistant to acid 
• Tooth decay can cause damage to the enamel of your tooth. The enamel is the crown or guard of your tooth that prevents bacteria and acid from coming into your dentin. 

How does toothpaste remove stains?

• Toothpastes have abrasive particles that bind to teeth. A toothbrush rubs the toothpaste against the teeth to polish them in two ways:
  1. Mechanical Stain Removal Techniques
• abrasive compounds that physically scrub away surface stains. The abrasive particles create a gentle friction that break down and lift discoloration from tooth enamel without causing damage
• ingredients such as hydrated silica, calcium carbonate, and aluminum hydroxide are usually found in toothpaste

• Each particle is made carefully to scrub away the stain but not harm the tooth enamel- kind of like an exfoliator for your tooth

• Chemical Stain Dissolution Mechanisms

• Research published in the Journal of the American Dental Association shows that: “low concentrations of hydrogen peroxide and other bleaching compounds can chemically dissolve chromogenic (color-producing) molecules embedded in tooth surfaces.” (https://pmc.ncbi.nlm.nih.gov/articles/PMC8189144/)

• These chemicals break down the discolouration to lighten surface stains and prevent them from becoming stuck in the tooth
• This helps protect the tooth without damaging it
• Research we found suggests that a new chemical in whitening is now found in many toothpastes. 
• This chemical is known is blue caravine, which works by depositing itself onto tooth surfaces where it changes how teeth look

Controlled Variables:

• Batch of eggs
• same person to scrub the eggs
• Toothbrush
• Measuring spoon and amount
• Coffee amount
• Tea amount
• Cola amount
• Drying time
• Scrubbing time
• Egg dying time
• Same tap used to rinse with water

Manipulated Variable(s):

• Type of toothpaste.
• Immersion solution (coffee, tea, cola)

Responding variables:

• Amount of stain removed from egg
• Amount of stain on eggs
• Damage to egg shell from solution

1. Boil eggs for 15 minutes.
2. Dip eggs in brewed coffee for 11 hours to stain.
3. Let eggs dry for an hour.
4. Measure out ⅛ tsp of toothpaste A. 
5. Use toothbrush to apply toothpaste to one side of the egg in a circular motion. Brush for 2 minutes.
6. Let toothpaste sit for 5 minutes on egg.
7. Rinse egg under water for 10 seconds.
8. Place egg in carton to air dry and observe.
9. Once dry circle brushed area with Sharpie marker.
10. Repeat process with remaining 4 eggs.

• Egg A appears to have more stain removal than B
• Stains come off quickly
• C seems to be working the best (before we tested D & E)
• A has a larger space, but C seems to have more white showing on the egg
• C was the brightest at the beginning with coffee
• the eggs have some cracks and lines - maybe the coffee and cola damaged the shell?
• The kids toothpaste E seems to be working well – the eggs look brighter right away
• We saw that stains were scrubbing off as we brushed
• After 3 days of brushing – all of the eggs had at least some stain removed
• The tea was a lot lighter stain
• Coffee was the darkest stain

• We could see that some toothpastes worked faster than othersTable 1: Visual Scoring 

  1	No change	(stain appears dark)
  2	Some stain removed	(stain appears lighter)
  3	Moderate stain removal	(white egg shell showing with some dark stain left)
  4	Most stain removed	(white egg shell showing, minimal stain left)
  5	All stain removed	(white egg shell showing with no staining)

  Table 2: Observation Table 

  Trail	#1 Coffee	#2 Tea	#3 Cola
  Obs.	A	B	C
  1	4	3	5
  2	2	2	4
  3	3	2	4
  4	4	3	3
  5	3	2	3
  6	3	4	4
  7	2	1	4
  8	3	4	3
  Avg.	2.9	2.6	3.6

  Table 3: Results  Average Standard Deviation

  |
  | A | B | C | D | E | A | B | C | D | E | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Coffee  | 2.9 | 2.6 | 3.6 | 4.4  | 4.6  | 0.8 | 1.1 | 0.7 | 0.7  | 0.5 | | Tea  | 4.6  | 3.4 | 2.9 | 3.9 | 3.9 | 0.7 | 1.1 | 0.7  | 0.4  | 0.9 | | Cola  | 4.6  | 4.3 | 4.4 | 3.3  | 4.6 | 0.5  | 0.7 | 0.5 | 0.7  | 0.5 | | Overall  | 12.0 10.3 10.9 11.6 13.0 |
  |
  |
  |
  |
  |

  Highest Average Score = Green  Lowest Standard Dev = Green (Most Consistent Scoring) 

  |
  | Highest | Lowest | Rank Highest to Lowest | | --- | ------- | ------ | ---------------------- | | Coffee | E | B | E, D, C, A, B | | Tea | A | C | A, D & E, B, C | | Cola | A & E | D | A & E, C, B,D | | Overall  | E | B | E, A, D, C, B |

• It appears that toothpaste C was not the  effective. It removed a lot of stains, but not all.
• Toothmostpaste E removed almost all the stains from all 3 trials except a lower rank for trail #2- tea.
• Toothpaste A worked well consistently except for the trail #1- coffee.
• Overall, E scored the highest and B scored the lowest.
• From the other marks we see that (A crest 3d white) did the second best and was a close second to E 
• We would not recommend toothpaste (B) which is the Total deep clean, as it got the lowest score.

We have learned that our hypothesis was incorrect. The toothpaste we thought would work the best (C) did not work the best. It appeared that toothpaste (E) kids crest color changing removed the most staining. You can see this on our visual rating scale because (E) showed up most frequently. We learned that you can remove stains from teeth by using toothpastes that have abrasive particles and whitening chemicals (i.e. bleaching compounds). Toothpaste (E) likely worked the best because it has sodium monofluorophosphate which helps remove bacteria but not harm the tooth enamel. 

• When you brush your teeth everyday it helps keep bacteria off and keep your mouth healthy. It keeps prevent tooth decay by protecting your enamel, which means a bright white future!
• Visiting the dentist is important because they can examine your teeth and gums to see if they are healthy. Dentists can give you instructions on how to make your teeth and gums healthier, and fix problems you might have before it is too late.
• Oral health is an important part of your overall body health.
• when you brush your teeth you help your self from pain and tooth decay

• using a regular toothbrush rather than an electric. We may have had inconsistent brushing technique
• cracks in the eggs from boiling and/or brushing
• comparing pictures and comparing the real eggs might have different results
• eggs began to rot so we had to get rid of them. It would have been better to observe them a bit longer
• visual ranking survey could be subjective
• at the beginning of the experiment we let the toothpaste sit on the eggs, but realized we needed to have just brushing for 2 minutes, then rinsing right after so that the toothpaste wasn't on the tooth longer than it would be in real life

Website: https://www.scienceproject.com/projects/detail/intermediate/IC046.asp

Website: https://www.cda-adc.ca/en/oral_health/teaching_resources/eggsperiment.asp

Website:   https://www.cda-adc.ca/en/oral_health/teaching_resources/ectd_resources.asp

Website: https://ca.crest.com/en-ca/oral-care-tips/kids/a-fun-eggsperiment 

Website: https://www.canada.ca/en/health-canada/services/healthy-living/your-health/environment/fluorides-human-health.html

Website: https://www.cda-adc.ca/en/oral_health/faqs/fluoride_faqs.asp https://myhealth.alberta.ca/Health/Pages/conditions.aspx?hwid=custom.ab_dentalcare_fluoridechildhood_inst_child

Website: https://my.clevelandclinic.org/health/treatments/11195-fluoride

Website: https://www.scienceproject.com/projects/detail/intermediate/IC046.asp

Website: https://www.cda-adc.ca/en/oral_health/teaching_resources/eggsperiment.asp

Website: (Government Article) https://pmc.ncbi.nlm.nih.gov/articles/PMC8189144/

Person(s) - Laura & Peter Osadetz - data collection assistance

Person(s) - Danielle & Scottie Mah - data and result compiling

We would like to acknowledge our parents, Laura & Peter Osadetz, and Danielle and Scottie Mah for helping us with our observations, find sources of information, and support the experiment. Our family members gave us feedback from our Visual Ranking Scale and helped inform our analysis and results. Ms. Million, our teacher advisor and Ms. Mcneil helped to keep us on track.