Eidgenossische Technische Hochschule Zurich Nichtmetallische Werkstoffe

Eidgenossische Technische Hochschule Zurich

Eidgenossiche Technische Hochschule Zurich Nichtmetallische Werkstoffe

Peter Schaerer

Ludwig Julius Gauckler

Frank Filser

Peter Kocher

Heinz Luethy

Stefan Fecher

Peter Kreuder

Heiner Hoerhold

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

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Zurich, Switzerland

Peter Schaerer