Recently on the topic of nickel-chromium porcelain teeth toxic to the human body has become the focus of discussion following the “Sanlu poisonous milk powder” after the general public, and many patients asked whether they need to replace porcelain teeth, I extracted some of the physical and chemical nickel and human physiopathological reaction as follows: 1, nickel is a silver-white metal, tough texture, ductility Strong, magnetic, at room temperature does not react chemically with the oxygen in the air. Nickel is a nutritional trace element required by humans or animals, and can act as a cofactor or as a structural component in some special metalloenzymes. 3, nickel is the most common allergenic metal, the incidence of up to 29%. Clinically nickel dermatitis manifests as pruritic, papular or papular blistering dermatitis with some tylosis. Cases of nickel-titanium wire causing oral mucosal allergy have been reported, with red punctate damage and scattered ulcers on the oral mucosa. Nickel has also been reported to cause palm-toe pustulosis. 4, nickel compounds can cause kidney damage, hematuria, proteinuria, tubular urine. 5, nickel compounds on the immune system can trigger an immune response and lead to contact dermatitis and asthma. 6.Nickel compounds can cause a decrease in the number of sperm, reduced motility and increased malformation rate 7.Nickel can be transferred through the placenta and lactation and contact with the fetus, producing toxic effects on the developing embryo, interfering with the formation of organs and fetal development, thus causing fetal malformations. 8, nickel and nickel compounds have certain carcinogenic effects. 9, nickel long-term inhalation can directly affect including asthma, chronic hypertrophic rhinitis and sinusitis, nasal polyps and nasal septal perforation. 10, the kidney is the main clearance pathway after nickel absorption, saliva and sweat glands can also excrete nickel. 11, nickel as an important anti-corrosion element, it is often used to make special steel, alloys, catalysts and electroplating, and therefore widely used in industrial and agricultural production, national defense and people’s daily life. Orthopedic use of fixed plates, screws, gynecological use of the contraceptive ring, cardiovascular use of the stent; stainless steel cups, stainless steel pots and pans, stainless steel chopsticks, stainless steel home and hot pot used in daily life contain nickel-chromium. 12, there is no report on the use of stainless steel tableware poisoning. 13.Nickel-chromium porcelain teeth are widely used and have a long history in China. 14, nickel-chromium porcelain teeth in the mouth only a very small part of the exposure in the mouth, to be dissolved in saliva first, and then absorbed in the digestive tract, its absorption is extremely small. 15, nickel is one of the necessary elements of the human body, the human body contains about 10 grams of nickel. 16, A person takes in about 0.16-0.9 mg of nickel from food daily. In summary, excessive intake of nickel is extremely harmful to the human body, while trace amounts of nickel is an essential trace element for the human body. Therefore, adverse reactions due to nickel-chromium porcelain teeth are extremely rare adverse events and are not determinable, so do not panic. However, based on the possibility of adverse reactions or psychological reasons, it is recommended that the economic conditions permitting conditions as far as possible not to use porcelain teeth and movable brackets containing nickel-chromium, has been used, such as adverse reactions can consider removing nickel-chromium porcelain teeth or stop using movable dentures containing nickel-chromium alloy, no adverse reactions can continue to use at ease. After all, people’s constitution is different, for example, some people are born with allergies. If you have been using for a long time and no reaction, there is no need to replace.