Porcelain veneers are used to modify the shape and color of teeth. Veneers are thin shells of porcelain that are etched and then bonded to the enamel of the teeth. A small amount of tooth structure must be removed to make room for the porcelain veneer and to avoid making the tooth look big and bulky. The tooth preparation is limited to the enamel and usually involves only a few surfaces of the tooth, unlike acrown or cap. A prosthodontist uses porcelain veneers to improve the appearance of teeth and to even close spaces or gaps between teeth.