The following Action News Extra report by Kelly Frey first aired May 15, 2006, on WTAE Channel 4 Action News at 11 p.m.

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Who doesn't love the feeling of clean teeth?

Rachelle Kuchar scrubs her teeth twice a day and stows her brush safely in a drawer.

Kuchar: "I line the drawer, so I am hoping that if I throw it in there, it is semi-clean."

Maybe that protects it from other bathroom nasties, but how clean really is your brush before you brush?

No matter where you keep your brush -- closed drawer, holder, medicine cabinet -- it's dark, and the brush stays damp.

Channel 4 Action News wanted to know how much bacteria is growing on your toothbrush in between brushes.

Dr. Gary Westerman and his first-year students at the Creighton University School of Dentistry put toothbrushes to the test.

Westerman: "We use a light to see the colonies better."

After just 24 hours, the results were downright disgusting.

Shannon Sena, student: "This is pretty typical. We had 14 samples that I counted yesterday, and they were all in the ballpark of about 2,000 colonies per person."

Westerman says that much bacteria over time can cause tooth decay and gum disease, and it's waiting for you the next time you brush your teeth.

The students took their study further by testing toothbrush sanitizers to see what worked. They soaked their brushes for 10 minutes in Listerine and in a prescription rinse called Peridex. They also tested a Violight, which is supposed to kill the germs.

The results? All three worked in banishing more than 99 percent of bacteria.

So scrub away -- but clean the brush before you brush, or you may just be spreading bacteria all over your teeth.

What about all those old wives' tales about how to take care of your brush? Here are the do's and don'ts.

• Do sanitize.
• Do allow the brush to air dry.
• Do wash the brush in your dishwasher.
• Do change your brush every three months or whenever you are sick.
• Don't store the brush in a drawer. That may trap bacteria inside.