The human mouth contains about 700 species of microorganisms, accounting for more number than the people on Earth. Improper rinsing of the brush after each use allows these species to grow on the brush. In fact, rinsing the bristles of the tooth brush every now and then with the mouthwash is a healthy habit. The tooth brush must be stored at least 6 feet away from the toilet, since airborne microbes from the toilet can settle on your tooth brush. Wet brush allows more organisms to form colonies in the moist environment and hence tooth brush must not be capped wet after use. Always allow it to dry after use & continue to store it in a dry environment. Replacing a tooth brush after any illness has been suggested by many dentists to prevent the potential for re-infection. However, we would like to differ on this view. We suggest a good rinse with mouthwash after an illness & recommend changing tooth brush only if it is old or worn out.