Sealants
Since the 1980s, in the United States, the incidence of tooth decay on the smooth surfaces of teeth has declined, in part because of fluoridation becoming widespread in public water supplies or because of improved dental hygiene among the public. However, because the teeth in the back of the mouth (molars and premolars) have numerous pits and fissures on their biting surfaces, certain areas of these teeth are often difficult to clean even with vigorous tooth-brushing.
