A veneer by definition is a thin sheet of material bonded to another material. In the case of dentistry, the thin material is either plastic or porcelain bonded to the surface of a cosmetically imperfect tooth. The tooth may be discolored, have fractures, show signs of wear, be the wrong size or shape, or be imperfect for a number of other reasons. The veneer covers the imperfection, making the tooth, or teeth look more esthetically pleasing.
Porcelain veneers are fabricated out of the mouth and then bonded to the teeth. Porcelain veneers can be thin allowing for a maximum amount of natural tooth preservation. However, if significant discoloration of the existing tooth exists, a thicker veneer might be required to hide the defect. Porcelain by nature has translucent properties which gives it a toothlike appearance and depth.
Composite Veneers (Bonding)
Composite veneers can be fabricated directly by layering composite resin material directly on the the tooth. The composite typically costs less than the porcelain option and often needs to be replaced more frequently.