Porcelain has long been a fast and effective way to repair discolored and decayed teeth. However, the metal ions within the metal porcelain will produce adverse reactions to the human body, such as gum darkening, gum bleeding, recession; and because of the presence of the metal inner crown, light transmission, color and shape and natural teeth have a large difference, but also in the light to produce a “greenish gray” effect. Therefore, the oral medical profession has been trying to change this state. Currently, the international dental community is popular is a newest metal-free crown porcelain teeth – all-porcelain teeth. All-ceramic teeth are widely used in some developed countries for their excellent performance, and are also the preferred restorative material for patients. Its superior performance is shown in: 1, no black line on the gum edge, no thick feeling, so you really feel like porcelain teeth are growing out of your own gums. 2, and the real teeth match the light transmission, no longer in the light “green teeth flashing” embarrassment. 3, and metal porcelain teeth comparable to the compressive strength, do not have to worry about the phenomenon of porcelain chipping. 4, no bad metal ions leaking out to affect your health. There are many systems of all-ceramic teeth, the most commonly used in clinical practice are the following: 1, cast porcelain two Empress system, Degudeng system, suitable for anterior teeth cosmetic restoration, tetracycline teeth veneer repair and replace the traditional fillings inlay restoration. 2, CERCON system: suitable for posterior restoration, bridge restoration with more missing teeth.