title: Analysis of three-dimensional sinter shrinkage of copings made from alumina in an innovative direct shaping process.
abstract: The three-dimensional (3D) evaluation and comparison of free-form-surfaces is a complex problem [Dent. Mater. 8 (1992) 49; J. Dent. Res. 76 (1997) 1799; Dent. Mater. 16 (2000) 145; J. Prosthet. Dent. 70 (1993) 457; Dent. Mater. 19 (2003) 19]. However, it is essential in order to analyze the sinter shrinkage of dental ceramic-restorations where isotropic and linear shrinkage is desired for accurate fit on the prepared teeth. In this article, we examine the 3D sinter shrinkage in general and for nine copings from alumina in particular. Using various scaled CAD-models in an iteration scheme, each model was compared to the filtered point cloud of the coping, determining the surface-cloud difference. The magnitude of deviations from linear sinter shrinkage was investigated. Furthermore, a new fabrication process for ceramic-restorations is introduced.
authors.affiliation: Department of Prosthodontics, Medical Faculty, University Hospital Carl Gustav Carus, Dresden University of Technology, Fetscherstr. 74, 01307 Dresden, Germany. eva-maria.brick@mailbox.tu-dresden.de
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Brick
authors.forename: Heike
authors.initials: H
authors.lastname: Rudolph
authors.forename: Jens
authors.initials: J
authors.lastname: Arnold
authors.forename: Ralph G
authors.initials: RG
authors.lastname: Luthardt
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D002516:Ceramics; D003764:Dental Materials; D008422:Materials Testing; D008962:Models, Theoretical
chemical_list: D003764:Dental Materials; D000537:Aluminum Oxide