1, the hardness of porcelain teeth is greater than human enamel, and it is brittle, which can cause wear on jaw teeth, and its internal crown is metal internal crown.

2. The hardness of all-ceramic teeth is softer than that of porcelain teeth, and the enamel is similar, which does not cause wear to jaw teeth. The inner crown is all-ceramic inner crown.

Second, the biocompatibility is different

1, all-ceramic teeth contain no metal, so they are not corroded by acid and alkali substances and will not cause allergies.

2. Porcelain teeth are based on metal, so they are easily corroded by acid and alkali.

Third, the appearance is different

1, all-ceramic teeth are transparent and more like real teeth.

2. The opaqueness of the metal crown of porcelain-fused-to-metal teeth requires opaque porcelain to cover the metal base, which affects the transparency of the restoration, making the porcelain-fused-to-metal teeth have obvious chalk color, paleness and falsehood after cosmetic treatment, and the "black source line" caused by the metal base at the neck of the teeth affects the appearance.

Refer to Baidu Encyclopedia-porcelain teeth and Baidu Encyclopedia-all-porcelain teeth for the above contents.