Sealants are a safe, painless, and low cost way to help protect your child's back teeth from decay. Sealants have been used on children's teeth for more than 20 years. A thin, plastic, tooth-colored or clear coating (sealant) is bonded to the chewing surfaces of the molars and premolars. This forms a hard shield that keeps food and bacteria from getting into the tiny grooves in the teeth causing decay.