1, Ni-Cr alloy porcelain crown:
Nickel and chromium are the main components. Nickel is about 73.6% ~ 87.6%, chromium is 12.4% ~ 26.4%, melting point is 1455℃, casting shrinkage is 1.8% ~ 2.3%, and its cobalt content is higher than that of nickel-based alloys, generally 25%, and Because nickel can react with saliva in the mouth to generate free nickel, which accumulates on the edge of the crown and gums, thus producing a well-known black line (gray staining).
2, titanium alloy porcelain crown:
Due to the limitation of titanium casting technology and equipment, it is impossible to cast titanium alloy raw materials in inert gas, but titanium alloy raw materials are cast in natural air. As a result, metallic titanium is oxidized and volatilized in the air. In addition, titanium itself is light in weight, so when centrifugal casting, titanium metal falls backwards and cannot enter the casting. The so-called "titanium alloy porcelain crown" does not meet the standard of 6% titanium. The actual titanium content is sometimes lower than that of nickel-chromium porcelain itself.
3, cobalt chromium crown porcelain teeth:
58.5%-64.5% of cobalt, 4.5%-7% of molybdenum and 26.5%-30% of chromium. It can be seen that cobalt-chromium porcelain abandons the addition of "nickel" and avoids the saliva toxicity of nickel metal.
4, pure titanium crown porcelain:
"Titanium" metal has excellent biological safety, light weight and high hardness. It has stable performance and is an ideal material for dental restoration. Pure titanium is the only metal that does not react with the body and is the medical metal with the highest biocompatibility. In addition, titanium metal is hard and difficult to deform, so it is a prosthesis with high neutral price of precious metal porcelain.
5, gold alloy internal crown porcelain crown:
Its inner crown contains more than 84% gold, platinum and palladium, which can not only reduce the weight of the prosthesis, but also strengthen its strength. It is not easy to have metal allergy, and it also contributes to the decomposition and absorption of protein in the body. It is the Jiao Jiao of precious metal porcelain. In addition, its unique pure yellow background color, combined with porcelain, simulated natural tooth index is very high. Because of the beautiful front teeth, it is still a good choice. Because it has the best metal elasticity and ductility and the strongest buffering ability, it is very suitable for tooth restoration and beauty with short root and poor bone, and its precision is relatively high. The price varies with the weight of gold. There are many kinds of porcelain teeth.
6, all-ceramic teeth:
All-ceramic production is to first fire the inner crown with porcelain material. The biggest difference between all-ceramic teeth and metal porcelain teeth is that the inner crown is made of porcelain, which is a transparent skeleton, and then the outer layer is fired with porcelain powder. All-ceramic has good light transmittance, no irritation to the body and strong natural feeling.
① Cast porcelain teeth: divided into three generations, the first generation is made of leucite as the inner crown, also called cast glass ceramics; The second generation used lithium-based ceramics as the inner crown. Also called alumina 95 corundum powder. The manufacturing process of casting porcelain teeth is to take a good tooth mold and cast it as a whole. Cast porcelain is a kind of all-porcelain, the full name should be "cast-pressed all-porcelain". The strength of the third generation has been greatly improved, and it is the best choice for aesthetic restoration of anterior teeth.
② Zirconia all-ceramic crown: Computer-aided monolithic porcelain block is used and semi-mechanically manufactured by milling machine. Its strength is very strong, comparable to metal porcelain. Non-toxic and harmless to the body, it contains no metal, but its strength is equivalent to that of metal porcelain. At present, the most ideal porcelain restoration, anterior teeth beauty restoration. Due to the improvement of zirconia technology, the thickness of abutment crown is reduced from 1 mm to 0.35 mm, the area of teeth to be ground is reduced, and the enamel loss rate is the lowest. Suitable for any high-end occasions that need porcelain making. It has no effect on future MRI and ct examination.