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Bacteriology Science Fair Project

Toothpaste Brands and Mouth Bacteria

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Toothpaste Brands and Mouth Bacteria | Science Fair Projects | STEM Projects
Does brushing with toothpaste actually reduce the bacteria in your mouth? You swab your teeth before and after brushing and spread each sample on an agar dish. Over four days you repeat the process with a different brand each day. After five days of growth you measure the diameter of each bacteria colony. Every brand reduces bacteria compared to the before-brushing sample. The results show which brand leaves the smallest colony behind.

Hypothesis

The hypothesis is that the amount of bacteria in your mouth will be reduced after brushing your teeth with toothpaste.

Method & Materials

You will prepare 8 agar petri dishes, use a disinfected swab to take samples from the participant's mouth, brush the teeth with 4 different types of toothpaste, and measure the size of the bacteria colony after 5 days.
You will need 8 agar petri dishes, 8 disinfected swabs, 1 bottle of disinfected water, 4 toothbrushes, 1 participant, 1 cup and water, 4 types of toothpaste, and 1 marker pen.

Results

The results showed that all the petri dishes with bacteria samples taken after brushing with toothpaste had a smaller amount of bacteria growth. The petri dish with Colgate toothpaste had the smallest sized bacteria colony.

Why do this project?

This science project is interesting because it shows how toothpaste can help reduce the amount of bacteria in your mouth and help keep your teeth healthy.

Also Consider

Variations: This science project may be repeated, this time, with swab sample from different locations in the mouth like the tongue. Modify the science project experiment, using different brands of mouthwash.

Full project details

Additional information and source material for this project are available below.

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