Full crowns can be all-metal crowns, metal porcelain crowns, gold-deposited porcelain crowns, all-porcelain crowns, etc. Among them, all-metal crowns are relatively strong, less grinding, no chipped porcelain and other problems, but not aesthetically pleasing, mainly used in posterior teeth that are not easily exposed, especially the maxillary posterior teeth; porcelain on a metal base crown becomes a metal porcelain crown, solving the problem of unattractive exposed metal, mainly used in the anterior and premolar areas, but the amount of grinding increases, there is the possibility of chipped porcelain. Gold deposited porcelain crown is similar to electroplating method first plated a thin layer of pure gold base, and then porcelain on it, and the fit is better than metal porcelain crowns, beautiful color, but softer, mainly used for anterior restorations. All-ceramic crowns are the most aesthetically pleasing crown restorations without a metal base. It is also divided into several categories: hot die-cast porcelain, alumina porcelain, and zirconia porcelain. Hot die-cast porcelain is the most permeable and naturally beautiful, but the strongest and is mainly used in the anterior region. Aluminum oxide porcelain and zirconia porcelain strength increased, can be used in the anterior molars and molars, but there is a layer of opaque porcelain white base, the need to bake porcelain on a porcelain base, aesthetic poorer than hot die-cast porcelain, the thickness increases, all-porcelain crowns with the largest amount of grinding. In short, the area that affects the aesthetics use porcelain crowns, people who value aesthetics use all-porcelain crowns, and parts that are not easily visible and have a high bite force (mainly the posterior maxillary area) can use all-metal crowns. The metal component of the commonly used all-metal and metal porcelain crown materials is either a nickel-chromium or gold alloy. These two differ in terms of organism allergenicity, heavy metal reactions, gingival irritation, gray lines on the crown margins, suitability of metal and porcelain, and the appearance of artifacts on MRI of the head and neck. Overall, gold alloys are recommended for their good biosafety and various physical properties, but they are more expensive and will change as the price of gold rises. After the doctor has informed the patient of the above mentioned types, it is the patient who makes the final decision on which restorative material to use. Patients can choose according to their requirements and circumstances.