A veneer refers to a thin layer of material bonded to a tooth. Veneers are usually done on upper front teeth, to change the shape and/or the colour of the tooth. A veneer is a much more conservative way of achieving this than placing a crown, which involves more tooth reduction. It is possible to do a veneer on one tooth, but it can be extremely difficult to match the colour and translucency of the surrounding natural teeth. It is common to have veneers done on the upper six front teeth, so they can be made to look more uniform.
Veneers are usually made of porcelain or composite resin. Porcelain veneers are made by the dental ceramic technician from an impression of the teeth. It is almost always necessary to grind some tooth away from the front and sometimes the biting edge of the tooth, to get a sharp margin that the veneer fits up to. Porcelain veneers cost more, but they can look superb and last longer than composite resin veneers.
Composite resin veneers, or laminates, are made of the same material used for fillings. They are built up directly onto the tooth. Because the material can be shaped into thin layers and tapered out to thin edges, tooth reduction is not usually necessary. For this reason, the thickness of the veneer will make the teeth look slightly more prominent. If tooth reduction is necessary to counteract this, then it would probably be worth considering porcelain veneers on such teeth.
The decision on whether to have porcelain or composite resin veneers depends on a few factors-
Porcelain veeers are usually done on older people, whose teeth are more likely to be mis-shapen and discoloured. The strength of the porcelain enables shorter teeth to be lengthened. The pulps in more mature teeth are less likely to be injured by the necessary grinding of tooth structure. Porcelain veneers provide the ultimate in aesthetics and last longer, but they also cost more.
Composite resin veneers are more often done on younger people, whose teeth usually require more modest cosmetic enhancement. They are not usually strong enough to lengthen the tooth much. Because tooth reduction is not usually done, the procedure is reversible, and they can also be reshaped and added to, if needed. Composite resin veneers usually look quite acceptable for most people, but will probably last around five years before staining around the edges becomes quite noticeable. They are cheaper than porcelain veneers.