(A) study of the physical properties of dental casting gold alloys used in Korea
The purpose of this study is to determine whether Korea dentists are using the proper types of dental casting gold alloys comparing with those alloys of American Dental Association specification, and to advice them on the use of the four types of casting gold alloys, since they have been only using the medium hard and hard gold alloys for many years.
Brumfield testing methods (1954) were used in testing the physical properties of medium hard and hard gold alloys, and also the four types of gold alloys which are composed in accordance with the range of composition of the American Society for Metals.
The tested physical properties are (1) ultimate tensile strength, (2) elongation per cent, (3) hardness, and (4) fusion temperature.
The result of study shows that medium hard and hard alloys are equal to the type Ⅱ and type Ⅲ of American Dental Association specification respectively. The prepared four types of alloys were tested and their physical properties fell within that range.
The result of this study recommends to the dentists of Korea that they consider the purities of the each component of dental casting gold alloys to have the proper types of gold alloys which equates to the American Dental Association Specification.
Therefore, the author is suggesting a new applied formula, the materials which can be purchased on the Korean market.
The result also recommends for using four different suitable types of gold alloys for restorations, instead of only two types.