A sealant is a clear or shaded plastic material that is applied to the chewing surfaces of the back teeth to help prevent cavities from forming in the developmental pits and fissures (grooves) of these teeth. These areas are where decay (cavity) occurs most often. The sealant is a liquid when placed on the tooth, so it flows into and fills up the pits and fissures of the tooth. A special light is shined onto the tooth which causes the sealant to harden, thus creating a barrier protecting the area from plaque and food which can lead to the formation of a cavity. The pits and fissures of your teeth are impossible to keep clean, because the bristles of a toothbrush cannot reach them. Therefore, these areas are snug places for plaque and bits of food to hide.
The best time to have a sealant placed is as soon as the tooth erupts through the gums into the mouth, and as soon as the tooth can be adequately isolated from saliva long enough to place and harden the sealant. If the tooth cannot be isolated for whatever reason, it should not be sealed, because the sealant will not adhere to the tooth and will therefore fail. In the very young patient, there is a lot of saliva in the mouth, and patient cooperation is at a low; therefore, sometimes it is necessary to wait until adequate isolation can be achieved. Adults can also be at risk for pit and fissure decay and thus be candidates for sealants. It only takes a few minutes to seal a tooth.
Just as with any other dental material, sealants wear down and eventually need to be replaced. Reapplication of the sealant will continue the protection against decay and may save the time, expense and destruction of having a tooth restored. The American Dental Association recognizes that sealants can play an important role in the prevention of tooth decay. When properly applied and maintained, they can successfully protect the chewing surfaces of teeth from decay.