Pit and Fissure Sealants • Back to Prevent Dental Disease Pit and Fissure sealants prevent cavity causing bacteria from invading the deep pits and grooves in your back teeth. These deep pits and grooves trap cavity causing bacteria and are almost impossible to keep clean with a toothbrush. Sealants are a plastic material applied to the chewing surfaces to form a protective barrier to bacteria.  Sealants are best suited for the first and second permanent molars that erupt around the age of 6 and 12. Before the sealants are applied, the tooth is prepared by using solutions that clean the tooth, and help the sealant stick to the enamel layer. Sealants may last for several years but should be checked regularly for normal wear by your Dentist or Registered Dental Hygienist. Sealants can easily be repaired or replaced if lost or worn.