When choosing the fixed denture metal, it will also involve the difference of the porcelain inner crown or the metal whole crown material. I will also briefly discuss it:

1. Nickel-chromium metal material, because it contains the element nickel that has a bad reflection of the human body, has now been basically abandoned:

1. Nickel has a slight carcinogenic and sensitization, resulting in green or inflammation and swelling of the gums;

2. The chemical properties of nickel element are unstable. Under the action of long-term oral environment, it will be slowly out, resulting in black coloring of gingival margin and the formation of black line, resulting in beauty.(This is not certain, but the highest incidence of nickel-chromium porcelain teeth and the lowest in gold porcelain teeth)

2. Cobalt-chromium metal material, now replacing nickel-chromium to become the so-called common metal material in oral clinical practice, is relatively cheap, which is cobalt and chromium, in which the content of the harmful element nickel is not more than one percent.

 However, on the one hand, compared with precious metal materials, cobalt element is easy to be released in the complex oral environment and lead to microleakage at the edge of the restoration, thus forming secondary caries and even bonding failure;

On the other hand, as the porcelain restoration of the front tooth, the bottom crown color of the cobalt-chromium material will still be expressed through the porcelain layer, and the aesthetic effect is not good. In addition, if the bridge restoration of multiple porcelain teeth, made of cobalt-chromium material quality, is also more thick than the precious metal material, it is not suitable.

 Three, 88 percent of the gold material, belongs to the top material in the porcelain teeth, the price is greater than or equal to the old tuhao gold.

 1, the chemical performance of gold and the stability of gold, not easy to oxidation, and excellent compatibility with the human body, so it will not stimulate the gums, will not lead to silver edge color change;

2. Its combination ability with porcelain powder is also the best, which is not easy to occur in porcelain collapse;

3. Because the gold material is soft and has a certain tolerance, the oral chewing process can act as the porcelain layer and the buffer band between the oral teeth, reducing the probability of abutment pain;

4. The gold is light yellow, which is the closest to the color of the normal permanent teeth, and the dentures produced have the best aesthetic effect.

 Four, pure titanium material

1. Pure titanium belongs to the metal material with the best compatibility with human body, and almost no one has allergic reaction to it, so it is also used in orthopedic bone collateral connection, implant and repair and other surgical treatment;

2, pure titanium strength is good, and the weight is light, so the bracket is thinner and lighter, the foreign body feeling is small, more comfortable to wear in the mouth;

3. The ductility of pure titanium metal is very good, so it can be more closely fitted with the model in the production process, so as to obtain better sealing in the mouth and achieve better retention effect;

4, pure titanium metal is easy to oxidation, on the one hand, the casting requirements are higher, thus increasing the cost, more expensive; on the other hand, after use in the aerobic oral environment for a period of time, the metal bracket will soon lose the original metallic luster, and covered with a dark oxide film.

 5, for porcelain tooth base crown, because the pure titanium material and porcelain gold porcelain combination performance is not good, so it is easy to lead to the porcelain collapse phenomenon, the rework rate is too high, so clinical doctors are not willing to use this material;

6. For full metal crown: because of pure titanium material, good ductility and soft texture, it is often used for patients with small occlusal gap, but also because of the same reason, it is very easy to be bitten through by patients within a long time. Of course, because of the high hardness and strength of titanium material itself, both mechanical cutting and high temperature melting casting is not easy, processing and modification are more difficult, so the use is not much.

 The above said is the porcelain denture, the so-called porcelain, is the inside is metal, the outer layer is covered with porcelain material, to make nearly the color and effect of natural teeth.

 The all-porcelain denture came in (in fact, it has appeared for 10 years, only nearly two years began to promote the application), as the name suggests, is from inside to outside all porcelain, no metal composition. The reason why it began to be applied in recent years is because the past porcelain materials, although high hardness, wear-resistant, but also very crisp, chewing food is very easy to crack, and as long as there is a crack in the porcelain interior, it will immediately break to the ground. Of course, the current all-porcelain teeth are not like this, thanks to the progress of material technology.

 I believe you can see the difference between the porcelain teeth above and the all-porcelain teeth below.