Production of dental shaped parts composed of porous glass

Patent metadata

Field	Value
Publication number	US-9901426-B2
Application number	US-201113993972-A
Country	US
Kind code	B2
Filing date	Dec 19, 2011
Priority date	Dec 17, 2010
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

The invention discloses a blank for producing dental shaped parts which consists entirely of porous glass without crystalline portions. The density of the blank is between 50% and 95% of its theoretical density. It has a discoidal shape with a diameter of at least 20 mm. The blank is produced by a process in which glass powder is first pressed at a pressure of between 10 MPa and 300 MPa and this green body is (pre-)sintered at a temperature of between 580° C. and 750° C. to form a blank of porous glass without crystalline portions. From the obtained blank, monolithic dental shaped parts can be obtained by mechanical processing followed by sintering, wherein a process according to the invention for stabilizing the shape of the shaped parts is used.

First claim

The invention claimed is:

1. A blank for producing dental shaped parts, characterized in that it consists entirely of porous glass without crystalline portions, wherein the density of the porous glass blank is between 50% and 95% of the theoretical density of the blank when it is in its densely-sintered state, and in that it has a disc-like shape with a diameter of at least 20 mm, wherein the glass consists of the following components:

SiO 2
55-65 wt.-%

Al 2 O 3
17-24 wt.-%

K 2 O
 5-9 wt.-%

Na 2 O
 7-11 wt.-%

Li 2 O
 0-1 wt.-%

B 2 O 3
 0-2 wt.-%

F
 0-1 wt.-%

TiO 2
 0-1 wt.-%

ZrO 2
 0-2 wt.-%

P 2 O 5
 0-1 wt.-%

SnO 2
 0-1 wt.-%

MgO
 0-4 wt.-%

CaO
 0-4 wt.-%

BaO
 0-4 wt.-%

Sb 2 O 3
 0-4 wt.-%

CeO 2
 0-8 wt.-%.

2. The blank according to claim 1 , characterized in that the density of the blank is between 55% and 85% of the theoretical density of the blank when it is in its densely-sintered state.

3. The blank according to claim 1 , characterized in that the diameter of the disc-like shape is at least 50 mm.

4. The blank according to claim 1 , characterized in that the thickness of the disk-like shape is more than 5 mm.

5. The blank according to claim 1 , characterized in that the blank has at least one recess for clamping the blank during the processing thereof to form a dental shaped part, wherein the at least one recess is provided on the outer circumference of the blank.

6. The blank according to claim 1 , characterized in that the density of the blank is between 70% and 80% of the theoretical density of the blank when it is in its densely-sintered state.

7. The blank according to claim 1 , characterized in that the diameter of the disc-like shape is at least 80 mm.

8. The blank according to claim 1 , characterized in that the thickness of the disk-like shape is between 5 mm and 30 mm.

9. The blank according to claim 1 , characterized in that the ratio of the diameter to the thickness is 4:1.

10. The blank according to claim 1 , characterized in that the ratio of the diameter to the thickness is 20:1.

11. Process for producing the blank according to claim 1 , characterized in that glass powder is pressed at a pressure of between 10 and 300 MPa to form a green body and said green body is pre sintered at a temperature of between 580° C. and 750° C. to form the blank that consists entirely of the porous glass without crystalline portions.

12. Process for producing the blank according to claim 1 , characterized in that glass powder is pressed at a pressure of between 100 and 200 MPa to form a green body and said green body is (pre)sintered at a temperature of between 620° C. and 660° C. to form the blank that consists entirely of the porous glass without crystalline portions.

Assignees

• Reinshagen Joerg
• Cramer Von Clausbruch Sascha
• Winterling Michael
• Ivoclar Vivadent Ag

Inventors

• Reinshagen Joerg
• Cramer Von Clausbruch Sascha
• Winterling Michael

Classifications

• A61K6/838

  Phosphorus compounds, e.g. apatite · CPC title

• C03C11/00 Primary

  Multi-cellular glass {; Porous or hollow glass or glass particles} · CPC title

• C03B19/06

  by sintering, {e.g. by cold isostatic pressing of powders and subsequent sintering, by hot pressing of powders, by sintering slurries or dispersions not undergoing a liquid phase reaction} · CPC title

• C03C4/0021

  for dental use · CPC title

• Y10T428/21

  Circular sheet or circular blank · CPC title