Because the occlusal (chewing) surfaces of molar and premolar teeth have grooves, called “fissures,” that trap food and accumulate bacteria-laden plaque, they are particularly susceptible to decay. These fissures can be deep and difficult to clean, which is why dentists often recommend that they be treated with “sealants.” These plastic coatings, which are brushed on the biting surfaces of the back teeth, quickly harden into protective barriers that seal out food, plaque, and bacteria. Because this treatment is so effective at preventing tooth decay, it is generally recommended for young children. However, the use of sealants is not limited to youngsters since adults can also benefit from their application. If sealants prevent one cavity, they are worth the cost.
P.S. While dental sealants only protect the surfaces upon which they are placed, fluoride helps protect all tooth surfaces from decay and cavities.