title: Fabrication of titanium alloy frameworks for complete dentures by selective laser melting.
abstract: BACKGROUND
  Casting difficulties have led to the limited use of titanium in dental prostheses. The selective laser melting system was recently developed to fabricate biomedical components from titanium alloys. However, the fabrication of a titanium alloy framework for a maxillary complete denture by selective laser melting has not yet been investigated.
  
  
  OBJECTIVE
  The purpose of the study was to fabricate thin titanium alloy frameworks for a maxillary complete denture with a selective laser melting system and to evaluate their hardness and microstructure.
  
  
  METHODS
  A cast of an edentulous maxilla was scanned with a dental 3-dimensional cone-beam computed tomography system, and standard triangulation language data were produced with the DICOM Viewer (Digital Imaging and Communications in Medicine). Two types of metal frameworks for complete dentures were designed with 3-dimensional computer-aided design software. Two titanium alloy frameworks, SLM-1 and SLM-2, were fabricated from these designs with the selective laser melting system. Plate-shaped specimens were cut from the central flat region of SLM-1, SLM-2, and as-cast Ti-6Al-4V (As-cast). Vickers hardness testing, optical microscopy, and x-ray diffraction measurements were performed.
  
  
  RESULTS
  Thin titanium alloy frameworks for maxillary complete dentures could be fabricated by selective laser melting. The hardness values for SLM-1 and SLM-2 were higher than that for the as-cast specimen. Optical microscopy images of the SLM-1 and SLM-2 microstructure showed that the specimens did not exhibit pores, indicating that dense frameworks were successfully obtained with the selective laser melting process. In the x-ray diffraction patterns, only peaks associated with the α phase were observed for SLM-1 and SLM-2. In addition, the lattice parameters for SLM-1 and SLM-2 were slightly larger than those for the as-cast specimen.
  
  
  CONCLUSIONS
  The mechanical properties and microstructure of the denture frameworks prepared by selective laser melting indicate that these dentures are appropriate for clinical use.
authors.affiliation: Assistant Professor, Gerodontology and Oral Rehabilitation, Department of Gerontology and Gerodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: m.kanazawa.gerd@tmd.ac.jp.
authors.forename: Manabu
authors.initials: M
authors.lastname: Kanazawa
authors.affiliation: Assistant Professor, Gerodontology and Oral Rehabilitation, Department of Gerontology and Gerodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Iwaki
authors.affiliation: Professor, Gerodontology and Oral Rehabilitation, Department of Gerontology and Gerodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Minakuchi
authors.affiliation: Associate Professor, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Nomura
mesh_terms: D000497:Alloys; D017076:Computer-Aided Design; D054893:Cone-Beam Computed Tomography / Q000379:methods; D003722:Dental Alloys / Q000737:chemistry*; D003734:Dental Casting Investment / Q000737:chemistry; D003735:Dental Casting Technique / Q000295:instrumentation*; D003779:Denture Design; D003827:Denture, Complete, Upper; D006244:Hardness; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007575:Jaw, Edentulous / Q000000981:diagnostic imaging; D007834:Lasers; D008437:Maxilla / Q000000981:diagnostic imaging; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys; D003722:Dental Alloys; D003734:Dental Casting Investment; C031462:titanium alloy (TiAl6V4); D014025:Titanium