Sealants are protective coatings which are usually placed on the chewing surfaces of back teeth, especially molars, to help prevent decay. The grooves and fissures in the back teeth can be extremely difficult to keep clean, and those grooves can be too deep for a toothbrush to even reach. These are areas where bacteria found in plaque can get trapped. They produce acid where they contact sugars that we eat. This acid will weaken the surface of the tooth, in time causing cavities. Sealants are a great way to help prevent the process of cavity formation.