However, due to the limitation of material performance and to ensure sufficient strength, it is often heavy or corroded; pure titanium bracket is lighter and biocompatible, but it is easy to have incomplete casting and poor fatigue strength. How to choose a biocompatible and lightweight metal 1, VITALLIUM system – high-grade cobalt-chromium Vitallium for Co cobalt-Cr chromium-Mo molybdenum alloy, the main composition of Co63%-Cr29%-Mo6%, containing 0.25% carbon. and contains 0.25% carbon. Its corrosion resistance and mechanical wear resistance are very high. The role of chromium and molybdenum in the alloy is to improve the strength and corrosion resistance; molybdenum can also prevent the crystallization of metal grain size, so that the structure is tight, thereby improving the fatigue resistance of the metal. Vitallium can maintain its high mechanical strength, high thermal corrosion resistance, and high oxidation resistance at temperatures between 730℃ and 1100℃. 2. Biocompatibility is very good. Biocompatibility: no allergic reaction without beryllium and nickel. 3.Good ductility: the adjustment performance is close to that of precious metals (fine-tuning) 4.Surface hardness is suitable: anti-fracture, anti-wear 5.The biggest advantage of good elasticity: more dense fit, not easy to deformation, wear into smooth. The elasticity of this material is incomparable to any existing bracket metal. Due to the good elasticity of this stent, the card ring is thinner, the palatal plate is thinner, and the performance of the material itself, the weight of the stent is greatly reduced and the comfort is greatly improved. The stent solves the problems of high weight of cobalt-chromium stent and poor comfort of pure titanium stent. Its mass is slightly heavier than that of the pure titanium stent, and its thickness is the thinnest of the three. The alloy purity of Vitaline stent is high, more antibacterial spot, anti-color, easy to clean, with the characteristics of gold alloy, high anti-corrosion function, anti-oxidation function, fatigue resistance, biocompatibility is very good, summarize the following characteristics: 1, the highest level of physical characteristics of cobalt and t alloy has achieved its excellent precision 2, does not contain nickel and beryllium, no allergic reaction to human body 3, no metal odor, unprecedented Fracture resistance, convenience and lightness 4, exquisite partial denture has a better appearance and more comfortable practical performance 5, highly polished surface makes the denture easier to clean and maintain the luster, resist the formation of plaque 6, less wear on adjacent teeth and restorations