You've got paperback and hardcovers for your books, warm comfy covers atop your bed, and even a snazzy headcover for your 3-wood. They protect what's on the inside, making sure it stays safe, unharmed, and clean. So what about a cover for your toothbrush? Does it help? Does it protect? Does it shield your toothbrush from all of the bacteria found in your mouth? Or does it hurt? Does it attract other bacteria outside your mouth? Read on to discover if a toothbrush cover is your friend or foe.