What percentage of gold, platinum, and palladium is found in high noble PFM copings?

High noble porcelain-fused-to-metal (PFM) copings contain a significant proportion of precious metals, which are primarily gold, platinum, and palladium. In dental materials classifications, high noble alloys are defined as those containing at least 60% noble metals. Usually, these alloys contain a high content of gold (around 50-60%), platinum, and palladium contributing to the total precious metal content which typically is around 70-80%.

The answer indicating 98% suggests an implausibly high percentage of noble metals for PFM copings. In practice, a formulation of 70-80% is more realistic and feasible considering the additional components like base metals that might be included for strength and cost-effectiveness. Thus, while the idea of having a very high content of precious metals like 98% seems appealing, it does not reflect standard practices regarding the composition of high noble PFM copings. The 70-80% range represents a more accurate characterization of the noble metal composition within these materials.