The chewing surfaces of the back teeth have natural deep grooves and depressions. The area is susceptible to decay because the bristles of a toothbrush don't always reach them and plaque can easily settle into the grooves. By sealing the grooves, you're creating a barrier to protect against the deposit of food and plaque and decreasing the risk of tooth decay. For the sealant to bond with a tooth, the tooth must first be cleaned to remove any debris. Finally, the sealant is brushed on the tooth and hardened with a special light.
Sealants vary somewhat in their longevity.
Part of this depends upon the bond achieved. The tooth location and hygiene habits of the patient also influence how long sealants will last. Generally, sealants have a very high success rate and can last up to ten years. For the maximum benefit from a sealant, it is recommended that children practice a complete preventive care program.