Sealants are thin layers of resin that are placed on the pits, fissures, and grooves of teeth to prevent decay on these surfaces.

Decay on posterior teeth commonly begins in the grooves and pits of chewing surfaces, especially during the first few years after their eruption. Sealing these surfaces with composite resin thus helps prevent decay. While sealants significantly reduce the overall chance of having cavities, it is still possible that decay may occur on surfaces in between the teeth.