According to China's current medical regulations, dentures are made by professional denture manufacturers, who usually bring a quality card to prove the metal composition of porcelain teeth, and some factories can also provide online inquiry services, which are all guarantees for the use of metals. If you have to ask for identification, you need to pull out the porcelain teeth and take them to the local technical supervision bureau for testing, or go to the steel market to buy a bottle of liquid medicine for metal composition testing. Cobalt-chromium steel has a special test method.