Cobalt-chromium porcelain is one of the non-precious metal porcelain teeth. It has the advantage of strong metal stability, high corrosion resistance, and generally no black gums or bleeding gums. Compared with precious metal porcelain teeth and all-porcelain teeth, the cost of cobalt-chromium porcelain teeth is obviously much lower. Compared to nickel-chromium porcelain teeth, cobalt-chromium porcelain teeth are safer. Cobalt-chromium porcelain teeth are typically non-precious metal porcelain teeth. Porcelain is a relatively advanced technique for dental veneers. It has the advantages of beauty, naturalness, strength and wear resistance, and is a favorite product for many dental patients. So what is the composition of cobalt-chromium porcelain teeth? Generally, it is not less than 25% chromium, not less than 4% molybdenum, and not less than 85% cobalt, nickel and chromium combined. The cobalt-chromium porcelain teeth, the good and bad, there are many different opinions. A part of people believe that the low price of nickel-chromium porcelain teeth are commonly used, porcelain teeth of more than 50% of patients choose this type of porcelain teeth. Biological integration is good, aesthetic, economic, durable and other advantages. However, some people confirm that the poor biointegration of this type of porcelain teeth can easily cause allergies in some people, resulting in inflammation of the skin and mucous membranes. The specific use of porcelain teeth should be discussed with the regular hospital attending doctor to make a decision. The choice of non-precious metal alloys used in the world is not the same. The United States uses more nickel-chromium alloy; while Europe and Japan used as a fixed restoration is basically cobalt-chromium alloy, containing more than 1% nickel is usually not used. Nickel-chromium alloy is easier to cast and more economical than cobalt-chromium alloy, but its physical properties and corrosion resistance are not as good as cobalt-chromium alloy. When exposed to a hot environment, such as in porcelain, the physical properties of NiCr may change and the alloy becomes more fragile and unsuitable for use as a long bridge. In this respect, cobalt-chromium alloys are much better than nickel-chromium alloys in terms of resistance to heat treatment (Morris
1990, Sing et al. 1999). In terms of corrosion resistance in the oral cavity, the corrosion performance of alloys without precious metals is fundamentally different from that of precious metal alloys. Precious metal alloys can prevent corrosion to a large extent because of their main components dimensional precious metal gold, platinum, palladium and or silver, these precious metals have a spontaneous composition of the passivated oxide layer. This is also reflected in the release of ions. On precious metal alloys, it is mainly the minor components, especially the bonding oxidizers and zinc, that undergo dissolution, while the corrosion phenomena of alloys without precious metals are determined by their major component cobalt. If according to the German industrial standard DIN
EN ISO10271 on corrosion made by the provisions of the view, gold alloy ion release lowest, followed by titanium, cobalt-chromium alloy and nickel-chromium alloy.