The Effectiveness of Various Toothpastes on the Bacteria on teeth

Water & Soil Microbes Experimenter Kit	Surface Microbes Experimenter Kit	Student's Microscopes
Age 10 +	Ages 10 and up	Ages 8 thru Adults

PURPOSE

The purpose of this experiment was to determine the effectiveness of various toothpastes in reducing the bacteria on teeth.

I became interested in this idea when I was brushing my teeth. I started wondering if the brand of toothpaste I was using was sufficiently removing the bacteria in my mouth. I knew that bacteria on teeth are the main cause of plaque, so reducing bacteria should improve the health of my teeth.

The information gained from this experiment could help dentists and consumers in our society to choose the type of toothpaste that would reduce bacteria best, thus improving dental health.

HYPOTHESIS

My hypothesis was that Colgate Total would reduce the amount of bacteria most.

I based my hypothesis on the fact that Colgate Total has the ingredient Triclosan, a strong antibacterial/antimicrobial agent.

EXPERIMENT DESIGN

The constants in this study were:
• Time between brushing and swabbing
• The teeth brushing method used by subjects
• Bacteria sampling method
• Time frame project was conducted
• Amount of time teeth were swabbed
• Type of toothbrush used
• Type of swab used
• Type of agar
• Type of Petri dish
• Incubation Time
• Type of incubator
• Incubation temperature at 35 degrees Celsius
• Students used daily for testing
• Amount of toothpaste on each toothbrush

The manipulated variable was the type of toothpaste.

The responding variable was the change in the amount of bacteria on the teeth before and after brushing.

To measure the responding variable, I counted the bacteria colonies visible on the agar plates after incubation.

MATERIALS