Fillings are used to restore teeth that are damaged by decay. The decayed tooth material is removed, the area is cleaned, and then the cavity or hole is filled with a special material. Sealants, on the other hand, are plastic coatings placed on the chewing surface of the permanent back teeth to help prevent decay.
Fillings
Composite Fillings. Composite fillings are just what the name implies: a mixture of resins and fine particles designed to mimic the color of natural teeth. Composite fillings provide a pleasing aesthetic alternative to amalgam (Silver) fillings. Sometimes composite resins need to be cemented or bonded to a tooth to allow for better adhesion.
Ionomers. Like composite resins, these materials are tooth-colored. Ionomers are made from a combination of various materials, including ground glass and acrylic resins. Because they are more fragile than dental amalgam, ionomers are typically used for fillings near the gum line or tooth root, where biting pressure is not a factor. A small amount of fluoride is released by these compounds in order to facilitate strengthened enamel in the affected area.
Porcelain (Ceramic). These materials are usually a combination of porcelain, glass powder and ceramic. Candidates for porcelain fillings are typically crowns, veneers, onlays and inlays. Unlike ionomers, porcelain fillings are more durable, but can become fractured if exposed to prolonged biting pressures.
Sealants
Sealants, liquid coatings that harden onto the chewing surfaces of teeth, have been shown to be highly effective in preventing cavities — even on teeth where decay has begun. The pits and grooves of your teeth are prime areas for opportunistic decay. Even regular brushing sometimes misses these intricate structures on the chewing surfaces of your teeth. Sealants are applied to the chewing surfaces and are designed to prevent the intrusion of bacteria and other debris into the deep crevices on the tops of teeth.
Sealants were developed about 50 years ago but didn't become commonly used until the 1970s. Today, sealants are widely popular and effective; young children are great candidates for preventive measures like sealants (especially on molars) because in many cases, decay has not set in. Even on teeth where decay is present, sealants have been shown to fight additional damage.