Sealants are a plastic material that fills in the deep pits and grooves of the chewing surface of teeth where cavities are more prone. Sealants are placed on adult molar teeth. These are most often placed on first and second molars coming in at age 6 and age 12. Sealants are a short simple and pain free procedure. Sealants are one of the best ways to prevent cavities on teeth that are decay free.