title: In vitro biocompatibility of CoCrMo dental alloys fabricated by selective laser melting.
abstract: OBJECTIVE
  Selective laser melting (SLM) is increasingly used for the fabrication of customized dental components made of metal alloys such as CoCrMo. The main aim of the present study is to elucidate the influence of the non-equilibrium microstructure obtained by SLM on corrosion susceptibility and extent of metal release (measure of biocompatibility).
  
  
  METHODS
  A multi-analytical approach has been employed by combining microscopic and bulk compositional tools with electrochemical techniques and chemical analyses of metals in biologically relevant fluids for three differently SLM fabricated CoCrMo alloys and one cast CoCrMo alloy used for comparison.
  
  
  RESULTS
  Rapid cooling and strong temperature gradients during laser melting resulted in the formation of a fine cellular structure with cell boundaries enriched in Mo (Co depleted), and suppression of carbide precipitation and formation of a martensitic ɛ (hcp) phase at the surface. These features were shown to decrease the corrosion and metal release susceptibility of the SLM alloys compared with the cast alloy. Unique textures formed in the pattern of the melting pools of the three different laser melted CoCrMo alloys predominantly explain observed small, though significant, differences. The susceptibility for corrosion and metal release increased with an increased number (area) of laser melt pool boundaries.
  
  
  CONCLUSIONS
  This study shows that integrative and interdisciplinary studies of microstructural characteristics, corrosion, and metal release are essential to assess and consider during the design and fabrication of CoCrMo dental components of optimal biocompatibility. The reason is that the extent of metal release from CoCrMo is dependent on fabrication procedures.
authors.affiliation: Institute of Surface Science and Corrosion, Department of Materials Science and Engineering 4, Friedrich-Alexander-University of Erlangen-Nuremberg, Martensstrasse 7, 91058 Erlangen, Germany; KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry, Division of Surface and Corrosion Science, Drottning Kristinas väg 51, 10044 Stockholm, Sweden. Electronic address: yolanda@kth.se.
authors.forename: Yolanda S
authors.initials: YS
authors.lastname: Hedberg
authors.affiliation: Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden.
authors.forename: Bin
authors.initials: B
authors.lastname: Qian
authors.affiliation: Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden.
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Shen
authors.affiliation: Institute of Surface Science and Corrosion, Department of Materials Science and Engineering 4, Friedrich-Alexander-University of Erlangen-Nuremberg, Martensstrasse 7, 91058 Erlangen, Germany.
authors.forename: Sannakaisa
authors.initials: S
authors.lastname: Virtanen
authors.affiliation: KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry, Division of Surface and Corrosion Science, Drottning Kristinas väg 51, 10044 Stockholm, Sweden.
authors.forename: Inger Odnevall
authors.initials: IO
authors.lastname: Wallinder
mesh_terms: D001672:Biocompatible Materials; D003722:Dental Alloys; D066298:In Vitro Techniques; D007834:Lasers; D014800:Vitallium
chemical_list: D001672:Biocompatible Materials; D003722:Dental Alloys; D014800:Vitallium
keywords: Additive manufacturing; Chromium; CoCrMo; Cobalt; Corrosion; Metal release; Microstructure; Protein; Selective laser melting