You wouldn't think of sharing your toothbrush. Not even with a family member. But it takes more than sole proprietorship to avoid partnering infection, reports the Academy of General Dentistry, an organization of general dentists dedicated to continuing education.

Studies show that toothbrushes can become heavily contaminated with oral microorganisms. Because most families store toothbrushes in a common storage space, airborne bacteria can move from toothbrush to toothbrush, passing opportunistic infections such as periodontal disease and the common cold from one person to another.

Your best defense is to go undercover. "The easiest way to protect your toothbrush is by using a toothbrush cover," advises Howard S. Glazer, DDS, FAGD, spokesperson for the Academy of General Dentistry.

Splattering water, contact with skin, and toothbrushes knocking against one another are all circumstances that contribute to the spread of bacteria. Dr. Glazer recommends rinsing bristles thoroughly, then shaking any extra moisture from the brush and storing it upright before placing a cover over the toothbrush head.

Studies also show a link between self-contaminated toothbrushes and oral inflammatory diseases. Bacteria from food particles and contact with the skin are unavoidable consequences of daily brushing. Dr. Glazer says people should wash their hands both before and after brushing, and soak unused brushes in an antiseptic mouthwash. Having more than one toothbrush makes this process a lot more practical. "The bathroom is usually the most contaminated room in the house," says Dr. Glazer. "Protect yourself by protecting your toothbrush."