How Dirty is My Toothbrush?

Remembering to brush twice a day may earn you props from your dentist, but failure to properly take care of your toothbrush doesn't do your mouth any favors.

The average toothbrush contains more than 10 million bacteria, including E. coli and Staph, according to a recent study at the University of Manchester in England. And researchers from the University of Alabama at Birmingham recently found that brushes stored in the bathroom—a.k.a. all of them—are contaminated with fecal germs, among other bacteria.

So which of your habits are perpetuating the problem? Follow these five tips to help keep your toothbrush and mouth as germ-free as possible.

1. Trade it out every 3 months.

Be honest: You probably don't think to change your toothbrush until you get your bi-annual teeth cleaning and your dentist sends you home with a freebie. But 6 months is way too long to use the same one—and guys who skimp on regular cleanings are probably sticking with it for even longer. “Old toothbrushes with worn and frayed bristles no longer clean your teeth effectively,” says Christopher T. Griffin, D.M.D., F.A.G.D., a South Carolina-based dentist and spokesperson for the Academy of General Dentistry. You should change your brush, or the brush head if you have an electric, every 3 to 4 months, he says. And toss it after you’ve been sick: Residual bacteria and viruses from an illness can cling to the brush and potentially re-infect you, Griffin adds. 

2. Upgrade your electric brush head.

If you go with a battery-powered cleaner, chose the head wisely: A new study from the University of Texas Health Science Center at Houston found that hollow heads have 3,000 more times the bacterial growth than solid ones. Unfortunately, most packages don’t specify the head design, so the best way to identify is through the connection to the body of the power toothbrush, says lead study author professor Donna Warren Morris, R.D.H. There will be some space to connect the two parts, but up to the bristles or brush head will be solid, she explains.

3. Disinfect it.

It’s important to disinfect your toothbrush between uses, Morris says. Some power toothbrushes now include an ultraviolet system, but you can also soak the head in mouthwash for 20 minutes. Consider submerging it even fresh out of the package. A 2011 study in Microscopy Research and Technique found that nearly half of never-before-used brushes were tainted with bacteria. Just don’t try and nuke it: A lot of people put their toothbrush through the dishwasher or microwave, and, while this will kill germs, it can also potentially damage the plastic and bristles, leaving you with a less effective cleaner, says Dr. Griffin.

4. Ditch the cover.

Plastic travel covers will probably help keep your toothbrush clean on the go, but ditch them when you’re home: “Microorganisms are more likely to grow in a moist environment, so don’t cover or store your wet toothbrush in a closed container,” Dr. Griffin advises. Keep it upright in a medicine cabinet that gets opened regularly, letting it air dry before your next brush.

5. Keep it away from the toilet.

Here’s the gross truth: Your toilet has a splash zone, and anything in the radius will probably get contaminated with fecal matter. In fact, pushing the handle can send particles splashing and floating as far as 6 feet away, according to the Harvard School of Public Health. “Limit the risk by closing the lid before flushing,” Dr. Griffin suggests. A 2012 study from the UK found that there were 12 times more germs around lidless toilets than those drained with the top down. Take extra precautions and store your toothbrush far, far away—preferably in a covered cabinet to protect it from any airborne bacteria.