Dental casting billet material, metal powder for powder metallurgy, dental metal component, and dental prosthesis

Provided is a dental casting billet material having excellent melt fluidity during casting, a metal powder for powder metallurgy capable of producing the dental casting billet material, a dental metal component produced by using the dental casting billet material, and a dental prosthesis produced by using the dental metal component. The dental casting billet material (1) is taken as a raw material for casting the dental metal component. An alloy forming the dental casting billet material (1) includes: Co as a main component; Cr in a proportion of 26% by mass or more and 35% by mass or less; Mo in a proportion of 5% by mass or more and 12% by mass or less; and Si in a proportion of 0.3% by mass or more and 2.0% by mass or less, wherein the billet material (1) is formed from a sintered body of a metal powder, and the billet material has a relative density of 92% or more and 99.5% or less.