Vita Zahnfabrik H. Rauter Gmbh Co. Kg

Michael Tholey

Norbert Thiel

Michael Dorn

Joachim Bibus

Birgit Huber

Michael Godiker

Vilma Geske

Enno Bojemueller

Wolfgang Rauh

Vanik Jinoian

Enno Bojemüller

Michael GÖDIKER

A non-dense sintered ceramic molded body having at least two layers, wherein a first powdery ceramic material forming a layer is contacted with at least a second powdery material forming at least a second layer. The body has a color gradient and maintains dimensional stability during sintering and forming. An admixing component and a common sintering temperature are used to control the volume decrease of the layers during sintering.

Non-dense sintered ceramic molded body having at least two layers

A process for producing a non-dense sintered ceramic molded body having at least two layers, wherein a first powdery ceramic material forming a layer is contacted with at least a second powdery material forming at least a second layer; said first powdery material has a presintering temperature Tthat is higher than the presintering temperature Tof said at least second powdery ceramic material; the course of a curve of shrinkage Sof said at least first powdery ceramic material differs from the course of a curve of shrinkage Sof said at least second powdery material, wherein curve of shrinkage Sis shifted towards higher temperatures as compared to curve of shrinkage S; and the layers are subjected to a common temperature treatment at a presintering temperature Tthat is lower than the presintering temperature Tand at least equal to Tto cause sintering that remains in a stage of sintering that has not proceeded to the theoretical density; wherein the curve of shrinkage Sis modified by admixing at least one component having a curve of shrinkage Swhich material is compatible with said powdery ceramic material into said first powdery ceramic material, i. e. has a grain size smaller than the first powdery ceramic material, to equalize the curves of shrinkage Sand Sin the region of the presintering temperature T.

Process for producing a non-dense sintered ceramic molded body having at least two layers

A porous, silicate, ceramic body, optionally with different colors, with a first density, can be sintered into a silicate, ceramic body with a second density, wherein the ratio of the first density to the second density is 2/5 to 98/100, and the three-point bending strength of the porous, silicate ceramic body with a first density, measured according to ISO 6872, is 25 to 180 MPa.

Porous silicate ceramic body, dental restorations and method for the production thereof

The present invention relates to a porous, silicate, ceramic body, possibly with different colors, with a first density, which can be sintered into a silicate, ceramic body with a second density, wherein the ratio of the first density to the second density is 2/5 to 98/100, and the three-point bending strength of the porous, silicate ceramic body with a first density, measured according to ISO 6872, amounts to 25 to 180 MPa.

Porous, silicate, ceramic body, dental restoration and method for the production thereof

An embodiment of the invention is a method for automatic calibration of dental furnaces, there is made available a dental furnace comprising a control unit adapted to control the dental furnace for performing a firing process defined by firing process parameters such as e.g. the temperature and/or a temporal temperature curve and/or a temperature gradient and/or a vacuum in a firing chamber of the dental furnace. There is provided at least one calibration firing-object sample made of a dental material, where said dental material, after said calibration firing-object sample has been subjected to a calibration firing-object process with predetermined firing process parameters, has a defined desired color stored e.g. in the control unit. Further, a color measuring device is used which, for transmission of measurement signals and/or measurement results, is operatively connected to the control unit.

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Bad Sackingen, Germany

Michael Tholey