Some patients’ incisors may be damaged or the nerves have been damaged, and the teeth are darkened, after professional root canal treatment, it is necessary to make restoration crowns, and it is very important to choose the material for restoration crowns, usually, incisors are more demanding due to their aesthetics, and it is recommended that the patients choose the all-ceramic porcelain teeth, which are more translucent, and are porcelain on the inside and the outside. If you choose metal porcelain teeth, there will be metal edges, long time metal free will make the gums black, affecting aesthetics, the choice of all-ceramic teeth is more ideal. All-ceramic teeth can choose cast porcelain, you can also choose zirconium dioxide all-ceramic, cast porcelain hardness than zirconium dioxide to be slightly worse, zirconium dioxide all-ceramic hardness will be better.