Porcelain teeth (crowns) with its color and texture similar to real teeth and can assume a better chewing function, so it is better than some other restorations in the clinic to get a lot of patients and doctors welcome, become a major means of restoration of oral dental defects, often carried out in various clinics. Porcelain crown porcelain layer color selection, for the patient’s appearance, does have a pivotal relationship, the clinical restoration is very important than the color. Generally, the doctor is to be restored to the patient two side of the adjacent teeth and the color of the opposite tooth as the basis for the choice of color, and then take into account the patient’s age and skin color to make a decision. If the natural extension of the color of different parts of the entire tooth surface is taken into account, such as the cervical part of the tooth is slightly yellow and the cut end is slightly transparent, etc., (of course, there is a good sculpture of the tooth shape), the final porcelain crown may be more lifelike, so that the patient adds confidence in quality of life. Because the porcelain crown is made of metal base layer for the inner liner, although the production process using a certain color masking (masking metal color exposed) treatment, but inevitably will bring the impact of the outer layer of porcelain powder, resulting in distortion of color. Therefore, the choice of metal liner (regardless of the biocompatibility of the metal), the porcelain crown color more or less also has a relationship.