Multilayer oxide ceramic body with aligned sintering behaviour
AssigneeIvoclar Vivadent AG
InventorsJörg Reinshagen, Henning Meyhöfer
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Abstract
Multilayer oxide ceramic bodies and in particular presintered multilayer oxide ceramic blanks and oxide ceramic green bodies, which comprise at least two different layers and are suitable for dental applications, wherein at least one layer contains La2O3 and the at least two different layers differ in their content of La2O3. These bodies can be thermally densified by further sintering without distortion and are therefore particularly suitable for the production of dental restorations. The invention also relates to a process for the production of such multilayer oxide ceramic bodies as well as a process for the production of dental restorations using the multilayer oxide ceramic bodies.
Claims13
A presintered multilayer oxide ceramic blank for the production of dental restorations, which comprises at least two different layers,
- wherein at least one layer comprises at least one coloring element selected from Fe, Cr, Er, Pr, Mn and Tb, at least one layer comprises La2O3 and the at least two different layers differ in their content of La2O3,
- wherein at least one layer comprises Y2O3, and the content of Y2O3 differs between the layers,
- wherein the layer with the lowest Y2O3 content comprises La2O3 and the layer with the highest Y2O3 content comprises Al2O3 and/or MgO, and
- wherein the sintering behaviour of the at least two different layers is aligned such that the blank can sinter without distortion, in which the proportion by weight of La2O3 in each of the at least two different layers is calculated according to the following formula:
- m
-
- (
- La
- 2
-
- O
- 3
- )
- =
- m
- min
-
- (
- La
- 2
-
- O
- 3
- )
- +
- (
- m
- max
-
- (
- Y
- 2
-
- O
- 3
- )
- -
- m
-
- (
- Y
- 2
-
- O
- 3
- )
- )
- *
- f
- ,
- wherein
- m(La2O3) is the proportion by weight of La2O3 in the respective layer, mmin(La2O3) is the minimum proportion by weight of La2O3 of all layers,
- m(Y2O3) is the proportion by weight of Y2O3 in the respective layer,
- mmax(Y2O3) is the maximum proportion by weight of Y2O3 of all layers, and
- f is in the range of from 0.01 to 1.00.
A presintered multilayer oxide ceramic blank for the production of dental restorations, which comprises at least two different layers,
- wherein at least one layer comprises at least one coloring element selected from Fe, Cr, Er, Pr, Mn and Tb, at least one layer comprises La2O3 and the at least two different layers differ in their content of La2O3, in which the proportion by weight of La2O3 in each of the at least two different layers is calculated according to the following formula:
- m
-
- (
- La
- 2
-
- O
- 3
- )
- =
- m
- min
-
- (
- La
- 2
-
- O
- 3
- )
- +
- (
- m
- max
-
- (
- Y
- 2
-
- O
- 3
- )
- -
- m
-
- (
- Y
- 2
-
- O
- 3
- )
- )
- *
- f
- ,
- wherein
- m(La2O3) is the proportion by weight of La2O3 in the respective layer, mmin(La2O3) is the minimum proportion by weight of La2O3 of all layers,
- m(Y2O3) is the proportion by weight of Y2O3 in the respective layer,
- mmax(Y2O3) is the maximum proportion by weight of Y2O3 of all layers, and
- f is in the range of from 0.01 to 0.20.
A multilayer oxide ceramic green body for the production of dental restorations, which comprises at least two different layers,
- wherein at least one layer comprises at least one coloring element selected from Fe, Cr, Er, Pr, Mn and Tb, at least one layer comprises La2O3 and the at least two different layers differ in their content of La2O3, in which the sintering behaviour of the at least two different layers is aligned such that the green body can sinter without distortion, in which the proportion by weight of La2O3 in each of the at least two different layers is calculated according to the following formula:
- m
-
- (
- La
- 2
-
- O
- 3
- )
- =
- m
- min
-
- (
- La
- 2
-
- O
- 3
- )
- +
- (
- m
- max
-
- (
- Y
- 2
-
- O
- 3
- )
- -
- m
-
- (
- Y
- 2
-
- O
- 3
- )
- )
- *
- f
- ,
- wherein
- m(La2O3) is the proportion by weight of La2O3 in the respective layer,
- mmin(La2O3) is the minimum proportion by weight of La2O3 of all layers,
- m(Y2O3) is the proportion by weight of Y2O3 in the respective layer,
- mmax(Y2O3) is the maximum proportion by weight of Y2O3 of all layers, and
- f is in the range of from 0.01 to 0.20.
Dependencies are inferred from the claim text.