Dental veneers (sometimes called porcelain veneers or dental porcelain laminates) are wafer-thin, custom-made shells of tooth-colored materials designed to cover the front surface of teeth to improve your appearance in cosmetic dentistry.
American Dental Association
The defect to be corrected is very severe or the tooth is practically destroyed. Tooth enamel is eroded due to, for example, bruxism or tooth carving. In these cases, a crown or an implant may be the best alternative.
Excessive spacing, crowding, open bites, overbites, cross bites, under bites, and abnormal teeth eruption also prevent the placement of veneers. In these cases, braces or clear aligners may be the best alternative.