In dentistry, a<unk> is a layer of material placed over a tooth.<unk>  can improve the aesthetics of a smile and protect the tooth's surface from damage. There are two main types of material used to fabricate a<unk>  composite and dental porcelain. A composite<unk> may be directly placed (built-up in the mouth), or indirectly fabricated by a dental technician in a dental lab, and later bonded to the tooth, typically using a resin cement. They are typically used for treatment of adolescent patients who will require a more permanent design once they are fully grown. The lifespan of a composite<unk> is approximately 4 years. In contrast, a porcelain<unk> may only be indirectly fabricated. A full<unk> crown is described as "a restoration that covers all the coronal tooth surfaces (Mesial, Distal, Facial, Lingual and Occlusal)". Laminate<unk>  on the other hand, is a thin layer that covers only the surface of the tooth and is generally used for aesthetic purposes. These typically have better performance and aesthetics and are less plaque retentive.
Veneer 
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