1, fixed dentures: fixed dentures is the use of missing teeth at both ends of the natural teeth or roots as the abutment teeth, by a variety of retainers, the dentures are glued to the abutment teeth, the patient can not take to wear. This kind of denture is stable, solid, comfortable, beautiful, can restore good chewing function and pronunciation function, wear very easy to get used to. However, with fixed dentures, the abutment teeth must be in normal shape, the roots are stable and the periodontal tissue is in good condition. 2, movable dentures: including partial movable dentures, full dentures. Active local dentures: is the use of missing teeth adjacent to the natural teeth, or other remaining teeth and mucosa together as a basis, through the ring and the base to stabilize the denture in the oral cavity, the patient can freely take wear, called local active dentures. Full dentures: used for full mouth without teeth patients, its retention mainly relies on the adsorption force and atmospheric pressure generated by the contact between the denture base and oral mucosa, due to the large base, patients feel uncomfortable at the beginning, it takes a period of training to get used to. 3, implant denture: including implant single crown, implant bridge, implant covered full denture Implant denture is the most advanced dental implant method, is to implant medical pure titanium biological metal artificial root (generally called implant) in the alveolar bone of the missing tooth area, after the implant is firmly bonded with the bone, the missing tooth is restored on the implant. Compared with the traditional dental implant method, dental implants are closer to the function and feeling of natural teeth, and are known as the “third set of human teeth” after the milk teeth and permanent teeth. 4.Dental implants have the following advantages? (1) Dental implants are similar to natural teeth in form, function and feeling, and meet the normal physiological requirements. (2) It has an independent artificial root, which does not need to wear the adjacent real teeth and protects the patient’s healthy teeth to the greatest extent. (3) It can restore the maximum chewing function, which is much better than traditional removable dentures. (4) Effectively prevent the alveolar bone from continuing to shrink after tooth loss. (5) Excellent stability and small size, minimizing the impact of dentures on pronunciation. (6) Realistic aesthetic effect, comfortable and hygienic, easy to use. (7) Can solve the problems that cannot be solved by traditional veneering methods.