Sealants are thin layers of resin that are placed on the pits, fissures, and grooves of teeth to help prevent decay. Decay commonly begins in the pits, grooves and fissures of the chewing surfaces of posterior teeth, especially during the first few years after their eruption. Sealing these surfaces with a think layer of resin helps prevent decay. While sealants significantly reduce the overall chance of getting cavities, they do not eliminate them for the simple fact that sealants don’t seal the entire surface of the tooth which would be impossible.