Sealants should be used as part of a child's total preventive dental care, usually placed at 6 and 12 years of age. Most tooth decay in children and teens occurs on the chewing surfaces of the teeth. Dental sealants are thin plastic coatings which are applied to the chewing surfaces of the molars (back teeth) to prevent decay. Applying sealants does not require drilling or removing tooth structure. It is an easy three-step process performed by the hygienist: We clean the tooth with a special toothpaste. A special cleansing liquid, on a tiny piece of cotton, is rubbed gently on the tooth and is washed off. Finally, the sealant is painted on the tooth and a special blue light hardens the sealant in about 15 seconds. One sealant application can last for as long as 5 to 10 years. Sealants should be checked regularly, and reapplied if they are no longer in place.