DEVELOPMENT OF DENTAL GOLD ALLOYS WITH AGE-HARDENABILITY AT INTRAORAL TEMPERATURE

1992 Fiscal Year Final Research Report Summary

• Project/Area Number: 03670919
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 補綴理工系歯学
• Research Institution: KYUSHU UNIVERSITY
• Principal Investigator: OHTA Michio KYUSHU UNIVERSITY FAC.DENTISTRY PROFESSOR, 歯学部, 教授 (30037824)
• Co-Investigator(Kenkyū-buntansha): NAKAGAWA Masaharu KYUSHU UNIVERSITY FAC.DENTISTRY RESEARCH ASSOCIATE, 歯学部, 助手 (80172279) ; SHIRAISHI Takanobu KYUSHU UNIVERSITY FAC.DENTISTRY ASSISTANT PROFESSOR, 歯学部, 講師 (10150468) ; MATSUYA Shigeki KYUSHU UNIVERSITY FAC.DENTISTRY ASSOCIATE PROFESSOR, 歯学部, 助教授 (00108755)
• Project Period (FY): 1991 – 1992
• Keywords: DENTAL GOLD ALLOY / EQUIATOMIC AuCu / LOW TEMPERATURE AGE-HARDENING / AuCu-Ga ALLOY / AuCu-Al ALLOY

Research Abstract

Dental gold alloys with age-hardenability at intraoral temperature were developed. Either 3 or 6 at% Ga,Al,Zn,In,Ni or Pd were added to the equiatomic AuCu alloy and the effect of additives on the low temperature age-hardenability was examined. Alloys containing Ga,Al or Zn exhibited excellent low temperature age-hardenability. The hardness of an alloy containing 6 at% Ga or 6 at% Al was doubled in one to ten days by aging at 37ﾟC. On the other hand,addition of Ni or Pd decreased the low temperature age-hardenability. Pronounced hardening was not demonstrated in an as-cast alloy,but solution treatment for only a few minutes provided enough age-hardenability. Age-hardening rate at low temperature related closely with the melting temperature of the alloy.
It is concluded that Ga,Al or Zn added AuCu alloy is expected to have enough age-hardenability for clinical use in the oral environment.