title: [Characters of the surface of the cast-bonded keeper: an experimental study].
abstract: OBJECTIVE
  This study is aimed to analyze the characters of the surface of the keeper after cast-bonded in varied temperatures.
  
  
  METHODS
  Twelve keepers were divided into three groups: the gold alloy group, the Ni-Cr alloy group and the Ti group with four samples in each group. A sample that contained a Magdisc 500 keeper was fabricated with the cast-bonded technique. Then, the surface of the sample was observed under scanning electron microscope (SEM) and its elements were analyzed with the electron probe.
  
  
  RESULTS
  The results showed that there was no oxide film on the surface of the keeper in the gold alloy group and the Ni-Cr alloy group, but there was an oxide film on the surface of the keeper in the Ti group. However, remains of the investment materials were found on the surface of the sample of three groups.
  
  
  CONCLUSIONS
  The study suggested that the casting temperature affect the characters of the surface of the cast-bonded keeper. Gold alloy or Ni-Cr alloy is of better properties for clinical use.
authors.affiliation: Department of Prosthodontics, College of Stomatology, Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200011, China.
authors.forename: Han-xi
authors.initials: HX
authors.lastname: Yao
authors.forename: Yuan-li
authors.initials: YL
authors.lastname: Zheng
authors.forename: Bin
authors.initials: B
authors.lastname: Wei
mesh_terms: D002858:Chromium Alloys; D003722:Dental Alloys / Q000737:chemistry*; D003735:Dental Casting Technique; D017268:Dental Prosthesis Retention / Q000295:instrumentation*; D006047:Gold Alloys; D008422:Materials Testing; D013499:Surface Properties; D014025:Titanium
chemical_list: D002858:Chromium Alloys; D003722:Dental Alloys; D006047:Gold Alloys; D014025:Titanium