Dental sealants are thin plastic coatings that are applied to the chewing surfaces of the back teeth to prevent decay. Most tooth decay in children and teenagers occurs on the chewing surfaces where pits and grooves tend to trap food and bacteria. Sealants fill in these pits and grooves so that bacteria cannot multiply and cause decay.
The narrow grooves in teeth can trap plaque. The longevity of sealants can vary. Any sealants that have remained in place for three to five years would be considered successful... sealants can last much longer. It is not uncommon to see sealants placed during childhood still intact on the teeth of adults. Any sealants that do come off sooner than three to five years should not necessarily be considered failures. Any length of time a sealant remains in place is a time period where it can offer a tooth protection.