Sealants are resin-based materials used to fill in the deep natural grooves on the chewing surfaces of molars.  These grooves can catch tiny food particles and bacteria, and cavities can easily develop in these areas.  By placing sealants in these grooves shortly after the six-year molars grow in, and again when the twelve-year molars erupt, your dentist can prevent the formation of cavities in these surfaces of the teeth.