Sealants Sealants are thin, white plastic coatings that are applied to the tops or chewing surfaces of back teeth and are highly effective in preventing tooth decay. The naturally occurring pits and grooves on the chewing surfaces of teeth can often collect plaque. These small grooves and cracks are the most susceptible to cavities in children and teens and benefit the least from topical fluoride. Sealants and fluoride work together to help prevent tooth decay. On average, sealants last for 5 to 10 years with proper maintenance. At every dental check-up, the dentist will check that the sealants are intact. In order to prolong the life of your child’s sealants, avoid crunchy foods and avoid chewing on ice and hard candy (i.e. Jolly Ranchers, Lifesavers, etc).