title: [Influence of cryogenic treatment and age-hardening heat treatment on the microhardness of palladium-silver dental alloys].
abstract: OBJECTIVE
  The purpose of this study was to investigate the influence of cryogenic treatment and age-hardening heat treatment on the micro-Vicker's hardness of palladium-silver dental alloys.
  
  
  METHODS
  A low-gold content dental casting alloy composed of Ag-Pd-Cu-Au was prepared for this study. Experimental specimens according to standard requirements were prepared following a standard dental laboratory casting procedure, cast specimens were heated to 900 degrees C and quenched in ice water. The specimens were then divided into 4 groups. They were subsequently subjected to different treatments, including age-hardening heat treatment, cryogenic treatment, heat treatment combined with cryogenic treatment. The non-treated group was used as control. The micro-Vicker's hardness value was examined. The significance of correlation was analyzed.
  
  
  RESULTS
  The micro-Vicker's hardness of specimens after age-hardening heat treatment, cryogenic treatment, heat treatment combined with cryogenic treatment increased by 129%, 13% and 141%, respectively, compared with that of the non-treated control group. Conclusion Age-hardening heat treatment and cryogenic treatment were effective in elevating the hardness of Ag-Pd-Cu-Au alloy.
authors.affiliation: Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Dept. of Prosthodontics, The Affiliated Hospital of Stomatology, Chongqing Medical University, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhao
authors.forename: Xu
authors.initials: X
authors.lastname: Tong
authors.forename: Jiajun
authors.initials: J
authors.lastname: Liu
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Hao
authors.forename: Yukun
authors.initials: Y
authors.lastname: Meng
mesh_terms: D003300:Copper; D003722:Dental Alloys; D006047:Gold Alloys; D006244:Hardness; D006358:Hot Temperature; D006801:Humans; D010165:Palladium; D012834:Silver
chemical_list: C120982:Ag-Pd-Cu-Au alloy; D003722:Dental Alloys; D006047:Gold Alloys; D012834:Silver; D010165:Palladium; D003300:Copper