Denture is divided into: fixed denture, full denture, removable partial denture and implant denture. 1.Fixed denture: The natural teeth at both ends or one end of the gap are used as abutment teeth, and a conscious retainer is made on the abutment teeth and connected to the artificial teeth to become a whole. ① Fixed bridge: It is composed of three parts: retaining bridge, bridge and connection body. ② According to the structure of the fixed bridge is divided into: double-end fixed bridge, semi-fixed bridge and single-end fixed bridge. The above are fixed bridges. The three basic types. The use of the above two or three basic types of fixed bridges made jointly called composite fixed bridge. ③ According to the different materials selected for fixed bridges are divided into: cast fixed bridges, porcelain fused to metal fixed bridges and all-ceramic fixed bridges (generally not done). 2.The denture made for patients with missing teeth is called full denture, which consists of two parts: the abutment and artificial teeth. According to the different materials, complete denture can be divided into conventional complete denture and implant complete denture. The full denture conventional full denture adhesive tray full denture casting full denture implant full denture immediate full denture 3, removable partial denture: is the use of natural teeth and abutment covering mucosa and bone tissue for support rely on the retention of the denture and the retention role of the abutment, artificial teeth to restore the form and function of the missing teeth, and use the abutment material to restore the shape of the defective alveolar ridge and soft tissue, the patient can remove a prosthesis The patient is able to remove it by himself. ① A removable partial denture usually consists of four parts: artificial teeth, abutment, retainer and connector. Types of artificial teeth: According to the material of artificial teeth, there are two types of artificial teeth: plastic abutments and porcelain teeth. According to the slope of the cusps of the fitting surface, there are anatomical teeth, non-anatomical teeth and semi-anatomical teeth. The types of abutment can be divided into metal abutment, plastic abutment and metal-plastic abutment according to the different materials. The types of retainers are divided into direct retainers, extra-coronal retainers (retaining ring type), and most common retainers. Indirect retainers (designed to prevent the denture from buckling, swinging, rotating, or sinking) are divided into large and small attachments. Permanent removable partial denture General removable partial denture General retainer. Removable partial denture Cast retainer. Invisible denture. Instant removable partial denture 4. Implant denture: It is a restoration consisting of dental implant and its supporting superstructure. ① Fixed implant denture by retention method. Removable implant denture. ② Classification according to the number of missing teeth and the restoration method Single tooth implant prosthesis. Multi-tooth implant prosthesis. Full jaw implant denture.