Dental sealants act as a barrier to help prevent dental decay. Cavities are very common on the chewing surfaces of molars, as food debris collects in the grooves and decays the tooth structure. As permanent teeth are erupting and the body is growing, many children do not effectively remove plaque and debris from their teeth. To prevent decay, dental sealants are placed over the chewing surfaces of the posterior teeth (molars and premolars) to create smoother surfaces that are easier to cleanse. Sealants do not last forever and may need to be repaired over the years.