Test Your Toothbrush I.Q.
Did you know the toothbrush was invented by the Chinese in the 15th century? These first toothbrushes were made of hog bristles. Today, most toothbrushes are made from nylon monofilaments which dry quickly and resist breakage. Did you know a worn-out toothbrush is dangerous? Bent bristles can injure soft tissues. Worn, frayed bristles won’t be [...]
