Chemicals contained in toothpaste may also kill bacteria. Killing bacteria lessens the formation of plaque. The plaque we are talking about is not an award hanging on the wall. This type of plaque is a thin layer on our teeth which contains pieces of food, saliva and bacteria. If plaque is not removed from our teeth, tartar, also called calculus, eventually forms.
Tartar is plaque that has hardened on our teeth.
Formation of tartar can then lead to cavities or gum disease, neither of which we want. Toothpaste helps to reduce tartar buildup, but only professional cleaning removes tartar. When toothpaste was first developed, its only function was to clean teeth. So, its composition was fairly simple. Your grandparents probably remember brushing their teeth with table salt or baking soda.