A full denture is a removable dental prosthetic for someone who has lost all the teeth on their upper or lower dental arch, or both. Because the tissue and bone around the teeth are resorbed following extraction, a full denture is also designed to replace the lost tissue and bone and help restore facial contours. The base of each full denture is a pink acrylic, similar in shade to normal gums, and the teeth are also usually acrylic. Under normal circumstances the lifespan of a full denture can be up to 8 or 10 years, though they will need to be relined every three to four years.