cast clasp made by cobalt-chromium alloy

What is a cast clasp made by cobalt-chromium alloy ? 
 It is the clasp which I cast dental cobalt-chromium alloy and produced. A clasp is a fixture to prevent dentures from working. I am if I go to the thing that is better than the clasp which the conformity for the tooth plane bends a wire and produced, the clasp tip and am thin at the thickness of the clasp arm, and, as for the cast clasp, what I can thin is an advantage.
 The dental cobalt-chromium alloy has a bigger tensile strength (strength) and hardness than a dentistry government funds alloy, and the feature is that growth is small. Because properties of matter decrease remarkably when atmospheric carbon gets mixed in the case of casting, what a thing, the segregation that I cannot use for casting repeatedly produce is matters that require attention. I can improve segregation if I perform equalization annealing, but the compatibility of the casting body might turn worse. Cobalt and the chromic ion are the elements which are easy to become the allergy to metal, but corrosion resistance is high, and the cobalt-chromium alloy is said to be it to be formed in the passivity metal surface if there is little ion elution. In Europe, cobalt-chromium alloy has begun to be used for porcelain firing use as a substitute alloy of the Ni-Cr alloy for porcelain firing from the 2000s. The Ni-Cr alloy adversely affecting the health of a dental technician processing this alloy, the price of money soars worldwide, and these backgrounds include that it becomes difficult to use a gold alloy.

 In late years the development of the 3D printer technology (addition production technique) is remarkable, and movement to apply to a dental prosthesis restoration thing in the dentistry industry is seen. 3D printer (the selective laser melting method) metal as for the cobalt-chromium alloy SLM method, direct metal laser sintering, Molding is enabled in DMLS method), and, in fundamental researches and a clinical study, a biocompatible evaluation (cell line) of the cobalt chrome molybdenum alloy powder for the compatibility evaluation for the abutment tooth model of the metal coping made by cobalt-chromium alloy for porcelain firing, 3D printers is performed. When a lot of conclusions such as the lost-wax process <CAD/CAM milling method < 3D printer method (the selective laser melting method) need the improvement of the compatibility, the compatibility is mentioned. 

Materials
 Surveyer, wax, a stock tray for single chin or individual tray, silicone rubber impression material, burying materials for fireproof model manufacture, plastic ring, vacuum kneading on fire harmony machine, phosphate system burying materials, dental cobalt-chromium alloy, high frequency casting machine, abrasion tool production method (Method of fabrication)
１．I take the double impressions of the tooth to cover with a clasp and produce a fireproof model.
２． Based on the information that I surveying and obtained, I design the clasp.
３． I upload wax on a fireproof model.
４．I perform it until sprue 植立, burying.
５．I heat to 800 degrees and cast it with a high frequency casting machine.
６．I calculate casting health and remove an oxidation film in alumina sandblast.
７． I fit and adjust it and study hard.

Discussion
１．Together with a model about the burying method (the fireproof model method)
 Because the cobalt-chromium alloy has high melting point, the shrinkage at the time of the casting is big. Therefore wax improves on the fireproof model which increased dimensions and manufactures a mold and I revise it and manufacture it. When direct wax improves on a working cast, a smallish casting body may be made without enough the expansion of the mold.
２． About the production of the clasp using a 3D printer technology
 Metal 3D printer (the selective laser melting method) The SLM method, the direct laser melting method, I sinter the powder of Co-Cr alloy and the Ti alloy which are DMLS method) or melt and come to be able to mold a clasp. In the study, the fatigue test of a molded clasp is carried out now. It is not evaluated the conformity precision.
 I mold a clasp pattern with 3D printer (liquid tank photopolymerization method, ink-jet method) of the resin and may produce a good casting clasp of the conformity precision by using every model together with the burying method and a lost-wax process. However, evaluations such as production precision or the surface coarseness are not accomplished.
 "270 EOSINT M dental" of EOS company began to sell it in Japan in 2015. This can mold a metal floor, a clasp, a crown, metal coping with exclusive cobalt-chromium alloy powder. The compatibility evaluation for the abutment tooth model of the metal coping made by cobalt-chromium alloy is accomplished by already in vivo in vitro and many researchers.

Conclusion
 I was able to produce a product made in good cobalt-chromium alloy cast clasp of the conformity precision by using the burying method together with a model this time.