Chromium-cobalt-molybdenum alloy

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The cobalt-chromium alloy belongs to the cobalt-based alloys . It is used in prosthetics , a branch of dentistry , to manufacture dentures . In technical jargon, it is often simply called an NEM alloy . Just as simplistic (and incorrectly) one speaks of a piece of steel in dental technology and means a model cast prosthesis .

Lower jaw prosthesis framework made from a chrome-cobalt-molybdenum alloy. In the higher resolution you can see the very fine modeling that has been poured out very well.


Depending on the manufacturer, the following values ​​differ slightly:

In addition, the alloys contain in small amounts: carbon , silicon , manganese and iron .


Physical Properties

Advantageous properties for use in dentistry

  • very fluid, so it enables the finest models to be poured
  • enormous hardness
  • enormous elasticity (twice as large as with precious metal alloys)
  • large bridge spans possible
  • completely corrosion-free
  • no discoloration in the mouth due to influences such as saliva or food
  • good soldering properties (important for prosthesis extensions)
  • physiological properties:
    • When using " biomaterials " such as gold , platinum or titanium , the physiological advantage over conventional non-precious metal alloys is emphasized . However, in the case of gold in particular, economic aspects presumably take precedence over those of patient welfare. Titanium is to be regarded as historical in prosthetics; it is used almost exclusively, and here very successfully, for endosseous implants and their superstructures. Silver-palladium alloys containing platinum are suspected of causing allergies.

See also


  • Paul Weikart: Materials science for dentists , 4th edition, Carl Hanser Verlag, Munich
  • Walter Hoffmann-Axthelm : Lexicon of Dentistry , Quintessenz-Verlag, Berlin