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

• US 10,266,452 B2
• Filed: 11/14/2013
• Issued: 04/23/2019
• Est. Priority Date: 07/21/2008
• Status: Active Grant

• Current Assignee: Vita Zahnfabrik H. Rauter GMBH & Co.. KG (Rauter Beteiligungsgesellschaft mbH)
• Original Assignee: Vita Zahnfabrik H. Rauter GMBH & Co.. KG (Rauter Beteiligungsgesellschaft mbH)
• Inventors: Thiel, Norbert, Dorn, Michael, Bibus, Joachim, Geske, Vilma, Tholey, Michael, Bojemueller, Enno, Huber, Birgit
• Primary Examiner(s): Snelting, Erin
• Application Number:
  US14/079,676
• Publication Number:
  US 20140070435A1
• Time in Patent Office: 1,986 Days
• CPC Class Codes: A61C 13/0003 Making bridge-work, inlays, implants or the like
• CPC Class Codes: A61C 13/0022 Blanks or green, unfinished dental restoration parts
• CPC Class Codes: A61C 13/083 Porcelain or ceramic teeth A61C13/081 takes precedence; preparations A61K6/80
• CPC Class Codes: A61C 13/20 Methods or devices for soldering, casting, moulding or melting A61C13/04, A61C13/081 take precedence
• CPC Class Codes: C04B 2111/00836 for medical or dental applications
• CPC Class Codes: C04B 2235/6022 Injection moulding
• CPC Class Codes: C04B 2235/6026 Computer aided shaping, e.g. rapid prototyping
• CPC Class Codes: C04B 2235/656 characterised by specific heating conditions during heat treatment
• CPC Class Codes: C04B 2235/6562 Heating rate
• CPC Class Codes: C04B 2235/6567 Treatment time
• CPC Class Codes: C04B 2235/6581 Total pressure below 1 atmosphere, e.g. vacuum
• CPC Class Codes: C04B 2235/661 Multi-step sintering
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/96 Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
• CPC Class Codes: C04B 2235/9607 Thermal properties, e.g. thermal expansion coefficient
• CPC Class Codes: C04B 2235/9615 Linear firing shrinkage
• CPC Class Codes: C04B 2235/9661 Colour
• CPC Class Codes: C04B 35/16 based on silicates other than clay zircon C04B35/48
• CPC Class Codes: C04B 35/64 Burning or sintering processes C04B33/32 takes precedence ; powder metallurgy B22F
• CPC Class Codes: C04B 38/00 Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof treating slag with gases or gas generating material C04B5/06 ; expanded graphite C04B35/536
• CPC Class Codes: C04B 38/0054 : the pores being microsized or nanosized

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.

Claims

1. A process for preparing a dental restoration comprising the steps of

partially sintering a metal-oxide containing feldspar green body to obtain a metal-oxide containing porous feldspar silicate-ceramic body having a first density, an ISO 6872 coefficient of thermal expansion (GTE) of at least 7×

10<sup>−

6</sup> K<sup>−

1</sup>, and an ISO 6872 three-point bending strength of 25-180 MPa,

milling the porous feldspar silicate-ceramic body to a precursor having the dental restoration shape,

positioning the precursor directly on a ceramic scaffold or metal scaffold, wherein the precursor is optionally coated with an opaquer before positioning on the metal scaffold, and

dense-sintering the precursor directly on, and fusing the precursor directly with, the ceramic scaffold or metal scaffold to obtain a ceramic-fused final dental restoration having a second density such that the first-density/second density ratio is 2/5-98/100.

2. The process of claim 1 wherein the silicate-ceramic body has an ISO 6872 coefficient of thermal expansion of 7-18×

10<sup>−

6</sup> K<sup>−

1</sup>.

3. The process of claim 1 wherein the silicate-ceramic body has an ISO 6872 coefficient of thermal expansion of 12-1.5×

10<sup>−

6</sup> K<sup>−

1</sup>.

4. The process according to claim 1, wherein the second density approximately corresponds to the theoretically reachable density of the ceramic body.

5. The process according to claim 1 further comprising the step of molding the metal-oxide containing feldspar green body before the partial sintering step.

6. The process according to claim 5, wherein the molded metal-oxide containing feldspar green body has a holding element.

7. The process according to claim 5, wherein the molded metal-oxide containing feldspar green body is embedded in a matrix.