title: The marginal fit of selective laser melting-fabricated metal crowns: an in vitro study.
abstract: BACKGROUND
  The selective laser melting technique is attracting interest in prosthetic dentistry. The marginal fit is a key criterion for fixed restorations.
  
  
  OBJECTIVE
  The purpose of the study was to evaluate the marginal fit of cast cobalt-chromium alloy crowns versus the fit of selective laser melting-fabricated crowns.
  
  
  METHODS
  The marginal gap widths of 36 single crowns (18 selective laser melting-fabricated cobalt-chromium metal crowns and 18 cobalt-chromium cast crowns) were determined with a silicone replica technique. Each crown specimen was cut into 4 sections, and the marginal gap width of each cross section was evaluated by stereomicroscopy (× 100). The Student t test was used to evaluate whether significant differences occurred in the marginal gap widths between the selective laser melting-fabricated and cast cobalt-chromium metal crowns (α=.05).
  
  
  RESULTS
  The mean marginal gap width of the cast crowns (170.19 μm) was significantly wider than that of the selective laser melting-fabricated crowns (102.86 μm).
  
  
  CONCLUSIONS
  Selective laser melting-fabricate cobalt-chromium dental crowns found improved marginal gap widths compared with traditional cast crowns.
authors.affiliation: Postgraduate student, Department of Prosthodontics, Stomatology Special Consultation Clinic, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China.
authors.forename: Dan
authors.initials: D
authors.lastname: Xu
authors.affiliation: Postgraduate student, Department of Prosthodontics, Stomatology Special Consultation Clinic, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China.
authors.forename: Nan
authors.initials: N
authors.lastname: Xiang
authors.affiliation: Associate Professor, Department of Prosthodontics, Stomatology Special Consltation Clinic, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China. Electronic address: weibin0328@hotmail.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Wei
mesh_terms: D002858:Chromium Alloys / Q000737:chemistry*; D017076:Computer-Aided Design; D003442:Crowns; D003734:Dental Casting Investment / Q000737:chemistry; D003735:Dental Casting Technique; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D007834:Lasers; D003765:Models, Dental; D012828:Silicones / Q000737:chemistry; D013499:Surface Properties; D019231:Tooth Preparation, Prosthodontic / Q000295:instrumentation / Q000379:methods
chemical_list: D002858:Chromium Alloys; D003734:Dental Casting Investment; D003764:Dental Materials; D012828:Silicones