The noble metal classification system has been adopted as a more precise method of reporting various alloys in dentistry commonly used in crowns, bridges and dentures. These alloys contain varying percentages of Gold, Palladium and/or Platinum. High noble contains more than 60% of Gold, Palladium, and/or Platinum (with at least 40% gold); noble contains more than 25% Gold, Palladium and/or Platinum; predominantly base contains less than 25% Gold, Palladium and/or Platinum.