The amalgam in dental filling materials contains toxic mercury. Amalgam is made of metals with different compositions, such as silver, copper, tin and mercury. Mercury becomes very stable when it is mixed with other metals.

Compared with the mercury absorbed by human body from food, drinking water and air every day, the mercury content released by amalgam is negligible.

Extended data:

(1) Mercury agent: composed of mercury and alloy powder; ?

Advantages: durable, relatively cheap, usually only need to see a dentist to complete the repair, self-sealing, no shrinkage or almost no shrinkage, leak-proof, less repair and replacement times.

Disadvantages: discoloration is not the natural color of teeth, and healthy dentin needs to be removed. A large amount of filling will weaken and fracture the rest of teeth, and temporary cold and hot allergies may occur due to the cold and hot transfer of metals.

(2) Resin: composite resin of synthetic resin and gutta-percha of natural resin; ?

Advantages: firm and durable, natural tooth color, one-time tooth filling, bending resistance, and maximum retention of teeth. If it is only bonded with tooth enamel, the risk of leakage is small, non-corrosive, and it is generally stable under the condition of hard chewing, but depending on the product, the tooth decay resistance is obvious, and the number of repair and replacement is small or low.

Disadvantages: there will be a certain degree of tooth allergy, which is related to the methods adopted by dentists.

It is more expensive than mercury compounds used for filling teeth, and the material will shrink after hardening, which will lead to further damage to teeth and/or cold and hot allergies.

(3) Metal salt cement powder: such as zinc phosphate cement powder.

Advantages: basically beautiful, because fluoride can be coated, which can prevent tooth decay to a certain extent, and only a small amount of dentin needs to be removed, because it can be well combined with tooth enamel and dentin under enamel.

The possibility of tooth allergy is low, and dentists can complete the restoration at one time.

Disadvantages: the cost is similar to that of synthetic resin material (its cost is higher than that of amalgam)

Because it is not a recommended material for surface restoration of adult occlusal teeth, its use is limited.

After a period of time, this substance may become rough and increase the possibility of periodontal disease.

Not wear-resistant, it will break loose over time.

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