Porcelain veneers are considered to be purely cosmetic because, unlike dental crowns, they do not completely encompass the entire tooth but only the labial surface with no more than 1mm preparation needed. However, porcelain veneers have the ability to treat cracks, chips, and broken teeth, as well as teeth which are chemically stained and therefore, do not respond to whitening treatments. Furthermore, porcelain venners are used to fill in unsightly gaps and spaces as well as make the teeth straight and white. The additional benefit of porcelain veneers is that they are comprised of a highly resilient porcelain, which not only responds as natural teeth do to whitening and other colorants but can be tinted to exactly match the teeth surrounding them. Porcelain veneers will respond like the enamel of natural teeth, retaining a uniform smile look over many years.