Other

Eidgenossische Technische Hochschule Zurich Nichtmetallische Werkstoffe

Holcim Technology Ltd

Ceramtec Ag, Innovative Ceramic Engineering

Eidgenossische Technische Hochschule Zurich

Dentsply Detrey G.m.b.h.

Eidgenossiche Technische Hochschule Zurich Nichtmetallische Werkstoffe

Ludwig Julius Gauckler

Frank Filser

Heinz Luethy

Peter Schaerer

Peter Kocher

Stefan Fecher

Peter Kreuder

Thomas Graule

Heiner Hoerhold

Urs Thomas Gonzenbach

Franziska Krauss Juillerat

Philip Noah Sturzenegger

Klaus Krumbholz

Wigbert Hauner

Ralf Janda

Christoph Kleinlogel

Gerhard Bayer

Martin E Hofmann

Atef Malash

Heinz Luthy

Hansjorg Janssen

Peter Scharer

Carmen Hofmann

Martin Goedickemeier

Felix Baader

A method for the production of a microcapsule, in particular a microcapsule of spherical shape having a hollow capsule space therein, includes the steps of: a) preparing of a suspension of particulate cementitious material in a solvent b) preparing a dispersion by mixing the suspension of step a) with an immiscible fluid so that (i) the suspension is present as a dispersed phase in the fluid as a dispersion medium or that (ii) the fluid is present as the dispersed phase in the suspension as the dispersion medium, such that the particulate material of the suspension adsorbs at least partially at a phase boundary between the fluid and the suspension, and c) allowing the particulate material adsorbed at the phase boundary to hydrate with the formation of a microcapsule.

Microcapsule

A microcapsule, in particular of spherical shape, having a hollow capsule core encased by a capsule shell, characterized in that the capsule shell is at least partially made of hydrated cementitious material. A method for the production of a microcapsule includes the steps of: a) preparing of a suspension of particulate cementitious material in a solvent b) preparing a dispersion by mixing the suspension of step a) with an immiscible fluid so that (i) the suspension is present as a dispersed phase in the fluid as a dispersion medium or that (ii) the fluid is present as the dispersed phase in the suspension as the dispersion medium, such that the particulate material of the suspension adsorbs at least partially at a phase boundary between the fluid and the suspension, and c) allowing the particulate material adsorbed at the phase boundary to hydrate with the formation of an individual microcapsule.

A holding device that can be braced in a surveying machining together with an individual preparation model produced by dental laboratory techniques. The holding device has a mechanically stable frame with bores disposed at a distance (a) to one another, in which at least two holding pins are locked that can be displaced at least in the axial direction (A).

Holding device for a denture or base structure model

A holding device comprises a cylindrical or prismatic, porous ceramic blank and elements for clamping in a machine tool for processing the blank by removing material, in order to produce a ceramic workpiece. A narrow frame is fixed by an adhesive connection over at least part of the periphery of the blank, which is held without stresses, in the area of a plane encompassing the longitudinal middle axis (A) of the blank. The frame only covers a small part of the surface of the blank and can be detached and held in a stable holder with a clamping adapter, in such a way that it cannot slide. The entire combination is fixed in the machine tool in such a way as to be resistant to twisting and sliding. The ceramic workpiece emerges continuously form the ceramic blank without predetermination of the advance direction, until holding segments which can then only be freely selected according to number and location have been formed. The holding segments end on the residual material of the blank in the area of the frame or on the frame itself. The holding device is used especially as a workpiece for producing fully ceramic dental prostheses, particularly crowns or bridges.

Holding device for a ceramic blank

The invention relates to an automatic machine tool, for the production of base structures, for false teeth, in particular, for tooth crowns and/or tooth bridges of exact three-dimensional shape. Said base structures may be fixed to prepared natural and/or artificial tooth stumps. The machine tool comprises a machine frame, or a body, a work piece carrier, with a rotation shaft, at least one digitization unit, at least one machining unit and an electronic arithmetic and control unit for all drive lines. A carrier for the workpiece, a blank, and/or for the machining unit(s), serves as displacement unit, with three translational axes in the x-, y- and z-directions. The digitization of the preparation model and the machining of the blank are carried out on the same machine tool, at different times. The machining paths for the blank are calculated from the measured and stored digitized data and a predetermined material-specific scaling factor, before the machining of the blank.

Machine tool for the production of base structures for false teeth

The invention relates to a process for production of a sintered oxide ceramic of composition Ce M D O with dense structure without open porosity or with a predetermined porosity. The first doping element M is at least one element of the group consisting of the rare earths but M&ne;Ce, alkali and earth alkali metals. The educts are used with a second doping element D of at least one metal of the group consisting of Cu, Co, Fe, Ni and Mn, in the submicron particle size or as a salt solution, and sintered at a temperature in the range of 750-1250&deg; C. into an oxide ceramic with extremely fine structure of a grain size of maximum around 0.5 &mgr;m.

Process for the production of sintered ceramic oxide

The well known slip casting process for the production of ceramic green parts, in which hardening is achieved by water removal with porous molds, is characterized by disadvantages in terms of strength, shrinkage during drying and problems with cracking during drying. The present invention avoids these disadvantages and produces ceramic green parts by changing the surface potential of powder particles in the slip instead of by removing water. Further more the coagulation strength is increased by adding polymers or extremely fine divided colloidal particles.

Method for the forming of ceramic green parts

A process for manufacturing a non-metallic dental prosthesis including a ceramic frame and an esthetic ceramic veneer including the steps of: preparing the ceramic frame by press molding a composition comprising from 1 to 50 parts by weight glass particles and from 50 to 99 parts by weight ceramic particles at a molding temperature from 800 to 1300.degree. C.; applying a slurry comprising a dental ceramic veneering composition to the thus prepared ceramic frame; and firing the ceramic frame having the slurry applied thereto at a temperature lower than the molding temperature to produce said dental prosthesis. The dental ceramic veneering composition may have a melting point at least 50.degree. C. less than the molding temperature.

Method of manufacturing a dental prosthesis

Process for producing ceramic green compacts by double layer compression

Growing community of inventors

Schaffhausen, Switzerland

Ludwig Julius Gauckler