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

Abstract

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.

1 . A porous silicate-ceramic body, optionally with different colors, having a first density that can be sintered to a silicate-ceramic body having a second density, wherein the ratio of the first density to the second density is from 2/5 to 98/100, and the three-point bending strength of said porous silicate-ceramic body having a first density as measured according to ISO 6872 is from 25 to 180 MPa. 
     
     
         2 . The porous silicate-ceramic body according to  claim 1 , the second density approximately corresponds to the theoretically reachable density of the ceramic body. 
     
     
         3 . The porous silicate-ceramic body according to  claim 1 , wherein the coefficient of thermal expansion (CTE) of the body is adjusted for use as a veneer material for a scaffold and, as measured according to ISO 6872, is at least 7×10 −6  K −1 . 
     
     
         4 . The porous silicate-ceramic body according to  claim 3 , wherein the CTE of the body as measured according to ISO 6872 is from 7 to 16×10 −6  K −1 . 
     
     
         5 . The porous silicate-ceramic body according to  claim 3 , wherein the CTE of the body as measured according to ISO 6872 is from 7 to 10×10 −6  K −1 . 
     
     
         6 . The porous silicate-ceramic body according to  claim 1 , designed as a molded member. 
     
     
         7 . The porous silicate-ceramic body according to  claim 6 , comprising a holding element. 
     
     
         8 . The porous silicate-ceramic body according to  claim 6 , embedded in a matrix. 
     
     
         9 . A dental restoration precursor obtainable by processing a porous silicate-ceramic body according to  claim 1 . 
     
     
         10 . A dental restoration obtainable by dense-sintering the dental restoration precursor according to  claim 9 , a sintering shrinkage being taken into account if necessary. 
     
     
         11 . A dental restoration precursor obtainable by processing the porous silicate-ceramic body according to  claim 1  and applying it to a complementary scaffold. 
     
     
         12 . A dental restoration obtainable by dense-sintering the dental restoration precursor according to  claim 11 , a sintering shrinkage being taken into account if necessary, onto the complementary scaffold. 
     
     
         13 . In a process comprising sintering a porous silicate-ceramic body to produce a dental restoration, the improvement comprising use of the porous silicate-ceramic body according to  claim 1 . 
     
     
         14 . A process for preparing the porous silicate-ceramic body according to  claim 1 , comprising the steps of:
 preparing a green body having the desired geometry;   if necessary, removing the binder from the green body to obtain a preform, optionally under vacuum;   sintering the preform to obtain a porous molded member, optionally under vacuum.   
     
     
         15 . A process for preparing a dental restoration, comprising the steps of:
 processing the porous silicate-ceramic body according to  claim 1  to produce a veneer;   positioning the veneer on a scaffold and subjecting it to sinter firing;   dense-sintering the restoration precursor into the final dental restoration; and   dense-sintering the veneer followed by positioning and bonding (by sintering, adhesive bonding, using a glass solder) to a scaffold.   
     
     
         16 . The porous silicate-ceramic body of  claim 3 , wherein the CTE is from 7 to 18×10 −6  K −1 . 
     
     
         17 . The porous silicate-ceramic body of  claim 4 , wherein the CTE is from 12 to 15×10 −6  K −1 .