1, dental implants: implants made of artificial materials are surgically implanted in the jawbone of the missing tooth area, and then the denture restoration is completed in the upper part of the implant, which plays the role of an artificial tooth root. Advantages and disadvantages of implant denture: Advantages: ① better support p retention and stability function; ② avoid tissue damage caused by conventional fixed denture abutment preparation (grinding small teeth); ③ denture without abutment or abutment area is small, with good comfort. Disadvantages: ① The disadvantage of dental implants is that they are more expensive. ② Dental implants are not suitable for all people, for example, the amount of bone and bone density in the missing tooth area is not ideal or suffering from systemic diseases are not suitable for dental implants. 2. Fixed denture: Generally, two neighboring teeth on both sides of the missing tooth area should be ground down, and then three artificial teeth (integrated) should be made to support and fix them. Advantages: high stability, high chewing efficiency, aesthetic. Disadvantages: For a few missing teeth, the teeth on both sides of the missing teeth need to be ground down Fixed dentures include porcelain (also known as metal porcelain teeth, consisting of two layers of metal and porcelain), all-porcelain teeth, metal teeth and so on. Porcelain teeth according to the use of different metals, there are nickel-chromium porcelain teeth, cobalt-chromium porcelain teeth, palladium-silver porcelain teeth, gold alloy porcelain teeth, etc., its casting precision, human compatibility, corrosion resistance and other differences. Nickel-chromium alloy has been less used, because there are reports of allergies, gum redness and other adverse reactions. All-porcelain teeth have cast porcelain teeth, aluminum dioxide all-porcelain teeth, zirconia porcelain teeth, etc., which have no metal, strong aesthetics and higher prices. 3, movable denture: rely on the elastic ring fixed on the adjacent teeth on both sides of the missing teeth, and need to be removed for cleaning after meals. According to the different materials, removable denture can be roughly divided into plastic-base removable teeth, cast metal-base removable teeth, including cobalt-chromium alloy, pure titanium. The plastic base denture is simple, less expensive and easy to repair, but the base is prone to fracture. Cast metal abutments are strong, not easy to break, can be made thinner and smaller, and feel comfortable, but more difficult to repair. The advantages of the removable denture: wide range of application, low cost, less tooth removal, disadvantages of the removable denture include: 1, the stability of the removable denture and chewing performance is poor, generally can not bite hard objects. 2, the movable denture is large, many parts, the initial wear patients often have a foreign body feeling, sometimes affect the pronunciation, cause nausea, need time to adapt 3, after meals and bedtime need to remove the denture cleaning, more trouble 4, the exposed metal ring affects the aesthetic. 5, denture design is not reasonable, poor quality, resulting in mucosal tissue damage (such as mucosal redness and ulcers), and even lead to the loosening of the abutment teeth, but also can cause temporomandibular joint disease (joint pain, popping) 6, movable denture plastic teeth after a long time use wear serious, affecting chewing performance, so movable denture need to be replaced once every 5.6 years. Different restoration methods have their own advantages and disadvantages, depending on the location of missing teeth, the number, the condition of adjacent teeth, the alveolar bone in the missing tooth area, the patient’s requirements and the economic situation.