title: Characterization of the interface between cast-to Co-Cr implant cylinders and cast Co-Cr alloys.
abstract: BACKGROUND
  The affordable Co-Cr cast alloy should provide an ideal interface with prefabricated cast-to cylinders from the same alloy family. The alloy microstructures should be maintained up to the interface, and porosities and reaction regions should be absent, and sufficient bond strength between alloys should be provided.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to evaluate the metallurgical interfacial compatibility between Co-Cr dental casting alloys and a prefabricated Co-Cr dental implant cast-to-cylinder.
  
  
  METHODS
  A Co-Cr alloy was cast to Co-Cr implant cylinders. Specimens were cross-sectioned longitudinally and divided into as-cast and heat-treated groups. The microstructures of specimens were evaluated by optical and scanning electron microscopy. The elemental composition of as-received prefabricated implant cylinders and diffusion characteristics of cast interfacial regions were determined by energy dispersive x-ray spectroscopy. Vickers hardness values were defined across the interface on cast specimens and for the as-received implant cylinders. ANOVA and Tukey honest significant differences tests were used for the statistical evaluation of hardness values.
  
  
  RESULTS
  No significant reaction regions or porosity were present in the interface. Microstructural aspect and interdiffusion indicated a metal-metal bond between the Co-Cr implant cylinder and cast alloy. Mean hardness values demonstrated a significant rise across the interface (373.5 ±12.8; 363.8 ±12.6, respectively) from the wrought cylinder (338.6 ±10.5; 329 ±9.7, respectively) to the cast alloy (399.8 ±7.4; 392.3 ±10.3, respectively) for the as-cast and heat-treated conditions, respectively.
  
  
  CONCLUSIONS
  Co-Cr casting alloy cast on to prefabricated Co-Cr implant cylinders provided interfaces which appear to fulfill the requirements of the established criteria.
authors.affiliation: Postdoctoral Scholar, Department of Prosthodontics, Faculty of Dentistry, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil. Electronic address: aozkomur@yahoo.com.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Ozkomur
authors.affiliation: Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Cukurova University, Adana, Turkey.
authors.forename: Yurdanur
authors.initials: Y
authors.lastname: Ucar
authors.affiliation: Assistant Professor, Department of Prosthodontics, Faculty of Dentistry, Cukurova University, Adana, Turkey.
authors.forename: Orhun
authors.initials: O
authors.lastname: Ekren
authors.affiliation: Professor, Department of Prosthodontics, Faculty of Dentistry, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Rosemary Sadami
authors.initials: RS
authors.lastname: Arai Shinkai
authors.affiliation: Professor, Department of Prosthodontics, Faculty of Dentistry, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Eduardo Rolim
authors.initials: ER
authors.lastname: Teixeira
mesh_terms: D002858:Chromium Alloys / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry; D001840:Dental Bonding; D003734:Dental Casting Investment / Q000737:chemistry; D003735:Dental Casting Technique / Q000295:instrumentation; D006801:Humans; D066298:In Vitro Techniques; D016062:Porosity
chemical_list: D002858:Chromium Alloys; D003722:Dental Alloys; D003734:Dental Casting Investment