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This science fair project was done to ascertain if brushing teeth with toothpaste will reduce the amount of bacteria in our mouths. The science project experiment involved using different brands of toothpaste - Colgate, Sensodyne, Aquafresh and Crest.


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

Scientific Terms

Micro-organisms, bacteria, plaque, fluoride, Triclosan, antibacterial


Dental hygiene

There are plenty of bacteria and other micro-organisms living in our mouth. These bacteria attack the food leftovers that stick to, and in between our teeth. They cause our teeth to decay, forming plaque and causing bad breath. When they digest sugar and starch that stick to our teeth, they produce acids that will dissolve tooth enamel.

Brushing our teeth everyday with toothpaste is very important for dental hygiene. Using toothpaste together with the proper brushing techniques can help in getting rid of plaque and also remove bacteria so that gum disease and loss of teeth can be prevented. Some types of toothpaste are even able to prevent bacteria growth and plaque formation.

The most important ingredient in toothpaste is fluoride. It helps in strengthening the tooth surface and prevents bacteria growth. It also helps to repair tooth decay in the early stages. Another ingredient in toothpaste that helps in fighting bacteria is Triclosan, an antibacterial agent.

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Complexity level:
Project cost ($):
Time required:
1 hour to prepare, 4 days for science fair project
Material availability:
Easily found
Safety concerns:

The bacteria should be destroyed before being disposed of. Pour some bleach into the petri dish to kill all the bacteria before disposal.