Socket crown denture is a removable partial denture with a socket crown as a retainer. The retainer consists of an inner crown and an outer crown, which are highly polished metal crowns bonded to treated natural teeth, while the outer crown consists of a metal ceramic crown and is connected to the other components of the denture to become a whole. The denture is cemented between the inner and outer crowns to generate retention force, so that the denture can be well retained and stabilized. Many elderly dental patients, not only part of the teeth loss, and often accompanied by the remaining teeth to varying degrees of loosening, elongation, tilt, the traditional metal ring denture, due to the ring on the natural teeth lateral force of the card holding role, so that the root of the tooth is injured, thus accelerating, aggravating the degree of loosening of the natural teeth, denture repair does not last a long time, and then the teeth fall out, the denture is scrapped, not only affects the physiological function, but also to increase the economic burden. Sleeve crown denture has the advantages of self-removal, convenient cleaning, small foreign body sensation, aesthetic, good functional recovery and so on. Especially, its biomechanical principle is different from ordinary movable dentures, which determines its excellent performance is unrivaled by other dentures. Sleeve crown denture can bear greater chewing force than ordinary movable denture, and produce higher chewing efficiency than ordinary movable denture; and sleeve crown denture has the therapeutic effect of periodontal splint for loose teeth caused by periodontal disease, and it can save the remaining teeth for a long time, which is suitable for missing teeth restoration of patients with periodontal disease. 1.Indications Higher number of missing teeth; periodontal disease, loose teeth with missing teeth, sleeve crown denture can achieve the therapeutic effect of repairing missing teeth and fixing loose teeth; excessive wear of teeth, sleeve crown denture can be occlusal reconstruction restoration; higher number of missing teeth, can not carry out the porcelain fixed bridge restoration; hope for cosmetic restoration. 2, Advantages Aesthetics and comfort, small size, no or little metal exposure, conducive to maintaining the health of periodontal tissues, easy to repair, strong and durable. 3.Disadvantages Complicated production, high technical requirements for clinicians and technicians, need to have expensive imported observation mills in order to carry out business, patients need to spend a higher cost. Sleeve crown denture in foreign countries is very widely used, removable denture prosthetic treatment, the use of sleeve crown as a retainer accounted for 53%. From the 90s of last century in China began to be used in the clinic, in the treatment of moderate to severe periodontal disease, the remaining few teeth in the dental defects in the restoration of the use of the technology to the case gradually increased, and is now in the Department of Restorative Medicine has been widely used.