Veneers are a thin layer of material made to fit over the front of the tooth. The amount of healthy tooth that needs to be removed varies. In some cases no preparation is required and the veneer can be placed directly on the tooth if there is space. In other situations, a small amount of enamel may be removed.
Veneers can be used for a variety of reasons including for cosmetic purposes (to change the colour and shape or size of teeth), to disguise markings on teeth such as fluorosis or enamel defects. They can also be used to protect teeth in some circumstances.
As well as using porcelain, white filling material known as composite may be used. If porcelain is used, most dentists will prepare the teeth and then send an impression/mould to the laboratory, where they can construct the veneer. This is then returned to the dentist for cementing, and in the meanwhile you may have some temporary veneers. If the veneers are made of composite, they can sometimes be done in one appointment and applied directly to unprepared teeth, but the technique used can vary depending on the dentist, patient and clinical situation.