Both permanent (at the age of five and a half years) and primary molars (that emerge after the second year), have very deep grooves that accumulate food and germs that can not be removed with a toothbrush. Usually there, at the deepest pit, dental caries begin. So a sealant is placed to protect the occlusal surtfaces of all permanent molars and some of the primary molars. A sealant is a varnish that permanently seals out debris and bacteria that can cause decay on the occlucal surface of posterior teeth.