Transcript Toothpaste Brand vs. Bacteria in your mouth

Toothpaste Brand vs.
Bacteria in your mouth
By: Nick Merriman
Question:
How does the brand of toothpaste you use
(Prevident 5000 Plus, Pepsodent, Tom’s of
Maine All Natural Organic) affect the
number of bacteria on your teeth when
brushing for 2 minutes in the morning
with the same toothbrush.
Hypothesis:
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If you change the brand of
toothpaste you use then the
Prevident 5000 Plus will remove
more bacteria than Pepsodent or
Tom’s because it is prescription
strength toothpaste.
Toothpaste Brands
Variables
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Manipulated: brand of toothpaste
Controlled: amount of time brushing
(2 minutes), type of toothbrush,
amount of toothpaste used (1
squeeze), time of day (morning)
Responding: number of bacteria
colonies on your teeth
Materials
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Prevident 5000 Plus: Dry Mouth
Pepsodent
Tom’s of Maine Natural Organic
6 sheep blood agar culture plates
6 sterile swabs
6 sterile inoculating loops
toothbrush
timer
Materials
Procedure
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Step 1-On the first day when you wake up note the time
and brush your teeth for 2 minutes with Prevident 5000
Plus
Step 2-Use the sterile swab to go over your top teeth and
your bottom teeth
Step 3-Using the swab, make a circle on the blood agar
about the size of a quarter
Step 4-Using the sterile loop spread a streak through the
circle area you swabbed , and continue spreading the
material out in 3 different directions on the plate. This will
let you see and be able to count the separate colonies of
bacteria.
2 minutes is a long time…..
Swabbing for the culture
Inoculating the agar
Procedure continued….
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Step 5: Place the blood agar culture in an incubator for 32
hours at 37 degrees Celsius (body temperature)
Step 6: Count the number of visible
Bacterial colonies growing on the plate and record.
Step 7: On the second repeat steps 1-6 for trial #2
Step 8: On the third and 4th day repeat steps 1-7 with
Pepsodent
Step 9: On the fifth and sixth day repeat steps 1-7 with
Tom’s of Maine
32 hours later…….lots of bacteria
Experimental Data
Number of Bacterial Colonies on Culture
(cfu = colony forming units)
Trial #1
Trial #2
Average
Prevident
5000
1337 cfu
1363 cfu
1352 cfu
Pepsodent 629 cfu
520 cfu
524.5 cfu
Tom’s of
Maine
1283 cfu
1318.5
cfu
1354
Conclusion
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My hypothesis was incorrect. The
Pepsodent cleaned your teeth the best,
not the Prevident 5000 Plus. The low was
520 cfu for the Pepsodent. The high was
1363 cfu for the Prevident 5000 Plus. The
difference between the two points was 843
cfu. Therefore I have learned that
Pepsodent cleans your teeth the best of
these three brands. To take this
experiment to the next step, you could
explore the different types of bacteria.