The top surfaces of your teeth, where the chewing takes place, aren’t smooth and flat.
They are criss-crossed with tiny hills and valleys called pits and fissures. These are places where plaque can build up and can be so deep and narrow that even a single bristle from your toothbrush can’t get deep enough to clean them out.
One method of preventing cavities from developing in pits and fissures is to clean them out and seal them off with a special strong resin to help protect the tooth from decay. Usually no local anaesthetic is required. Fissure sealants or preventive restorations are most commonly done on newly erupted molars of children which will give these teeth the best chance of longevity.