Dental sealants are a protective material that flows into the pits and grooves to prevent cavities on the chewing surface of the teeth.
When teeth form they often develop deep grooves that are smaller than a tooth brush bristle. These deep grooves often lead to cavities in the middle of the biting surface of the teeth. There is very little a patient can do to clean out these cavity prone areas. This is why many dentists will suggest placing a dental sealant over these deep groves to protect them and make the biting surface of the teeth able to be cleansed by the patient.