Veneered dental restoration with a controlled shade

1. Method for the manufacturing of a dental restoration by use of CAD/CAM technology, the dental restoration comprising a dental restoration core ( 2 ) and a veneer layer ( 3 ), the veneer layer ( 3 ) being located at predetermined locations on the dental restoration core ( 2 ) and having predetermined thickness at said predetermined locations;

the method comprising using the CAD/CAM technology to perform the steps of:

manufacturing the dental restoration core ( 2 ), comprising: milling a mould block ( 10 ) to cut away material of the mould block to form a void ( 5 ) and the dental restoration core ( 2 ) in the void, or milling a block of ceramic material to form a void inside the block ( 1 ) and the dental restoration core ( 2 ) in the void, wherein the void has a surface contour ( 7 ) that has open space ( 11 ) in areas where a veneer layer is to be created on the dental restoration core ( 2 );

filling the void ( 5 ) with the surface contour in which the dental restoration core ( 2 ) is positioned, in the block ( 1 ; 10 ; 20 , 21 ) with a slurry or paste containing a constituent material for a veneer layers

cold pressing the slurry or paste into the void ( 5 ), the void being arranged to have the slurry cover the dental restoration core ( 2 ) at at least the predetermined locations;

heating the slurry or paste in a hardening or pre-sintering process to obtain a hardened veneer structure covering the dental restoration core ( 2 );

milling a contour of the veneer layer into the hardened veneer structure to form the dental restoration ( 2 , 3 ); and

sintering the dental restoration.

2. Method according to claim 1 , further comprising dimensioning the milled contour of the veneer layer in such a way that a shrinkage during the sintering of the dental restoration ( 2 , 3 ) is compensated.

3. Method according to claim 1 , wherein the dental restoration core is connected ( 6 ) by a connector to a remaining part of the milled mould block in the mould block, the connector being formed by the milling process.

4. Method according to claim 3 , wherein the block ( 1 ) consists of a ceramic material based on zirconia.

5. Method according to claim 3 , wherein the block ( 1 ) consists of a consumable material wherein the consumable material is selected from a group comprising gypsum, chamotte, a wax, a material that can be removed by chemical disintegration.

6. Method according to claim 1 , further comprising creating the void ( 5 ) in the block ( 10 ) by milling,

wherein the surface contour ( 7 ) comprises a replica ( 8 ) of a portion of the jaw or one or more dental stumps of a patient, on which the dental restoration core is to be placed.

7. Method according to claim 6 , wherein the surface contour ( 7 ) has a contact area of the replica ( 8 ) of the jaw and/or dental stumps arranged for matching with a contact area of the dental restoration core ( 2 ) when the dental restoration core ( 2 ) is positioned on the surface contour ( 7 ).

8. Method according to claim 1 , wherein the block ( 20 , 21 ) comprises a lower mould ( 20 ) and an upper mould ( 21 ), the lower mould ( 20 ) and upper mould ( 21 ) are arranged for forming a compound mould block ( 20 , 21 ).

9. Method according to claim 8 , further comprising:

creating the void ( 5 ) in the block ( 20 , 21 ) by means of:

milling in the lower mould ( 20 ) for creating a surface contour 7 , wherein the void comprises a surface contour ( 7 ) which comprises a replica ( 8 ) of a portion of the jaw or one or more dental stumps of a patient, on which the dental restoration core is to be placed,

milling in the upper mould ( 21 ) for creating a second surface contour ( 17 ) which second surface contour ( 17 ) substantially corresponds to a surface contour of the veneer layer ( 3 ), and

mounting the upper mould ( 21 ) on the lower mould ( 20 ).

10. Method according to claim 9 , further comprising creating a runner in the block ( 20 , 21 ), the runner being arranged for guiding the slurry into the block ( 20 , 21 ).

11. Method according to claim 1 , wherein the constituent material for the veneer layer is a glass ceramic or an acrylic composite material.

12. Method according to claim 1 , wherein a further veneer layer is arranged on the dental restoration, comprising:

filling a void ( 5 ) in a mould block ( 1 ; 10 ; 20 , 21 ) with a slurry or paste containing a constituent material for a further veneer layer, the dental restoration ( 2 , 3 ) being positioned in the void ( 5 );

pressing the slurry or paste into the void ( 5 ), the void being arranged to have the slurry cover the dental restoration ( 2 , 3 ) at at least the predetermined locations;

heating the slurry or paste in a hardening or pre-sintering process to obtain a hardened further veneer structure covering the dental restoration ( 2 , 3 );

milling a contour of the further veneer layer into the hardened further veneer structure.

13. Method according to claim 1 , comprising:

providing the material of the dental restoration core ( 2 ) with a base colour, providing the constituent material of the veneer layer ( 3 ) with a surface colour, wherein the constituent material of the veneer layer is translucent.

14. Method according to claim 13 , comprising expressing a colour of the dental restoration ( 2 , 3 ) by controlling a thickness of the veneer layer ( 3 ).

15. Method according to claim 14 , wherein the veneer layer ( 3 ) has a local thickness between 0.2 and 2.0 mm.

16. Method according to claim 13 , wherein the base colour is highly pigmented in either reddish or red-yellow or yellowish and the veneer layer colour is low pigmented in an almost white colour.