A sealant is a clear or shaded plastic material that is applied to the chewing surfaces (grooves) of the permanent back teeth (molars), where four out of five cavities in children are found. This sealant acts as a barrier to food, plaque and acid, thus protecting the decay-prone areas of the teeth. The sealant is quick and easy to apply and generally will hold up for about 4 years before being worn down and a reapplication is needed. Seventy five percent of children with sealants do not develop decay on the sealed teeth. Some children are harder on their teeth than others, and chip or wear off the sealant faster. Sticky candy or gum during the first 24 hours after placing the sealants is the # 1 reason sealants come off.  If the sealant comes off the tooth, a cavity can occur in the same way that an unsealed tooth can decay.