Plaque is a bio-film of bacteria and mucous that grows on your teeth. Some of the bacteria in the plaque make acids which decay your teeth. Other kinds of bacteria in the plaque make toxins which cause gum disease. The easiest and most effective way to remove the plaque from your teeth is to brush and floss. Those costly rinses just don't do it! When the plaque is hardened on your teeth it is called tartar or calculus. Then you need a Dental Hygienist or Dentist to remove it by "scaling" the tartar off.