The chewing surfaces of the molar and premolar teeth have grooves – “fissures” – that make them vulnerable to cavities. These cracks can be difficult to clean, and may be narrower than a simple bristle of a toothbrush. Plate buildup in those areas, and acid in plaque attacks the enamel and cavities can form. Dental sealants provide additional protection for grooved and boneless areas, providing a smooth surface that covers most of the cracked area