← Back to Patent Explorer
EP0774933B1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Method of manufacturing ceramic tooth restorations

Assignee: Nobel Biocare AB
•
Filing: 1994-05-27
•
Granted: 2000-12-06
•
Expires: 2014-05-27
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract The present invention relates to a method of manufacturing artificial tooth restorations for natural teeth or implants comprising a ceramic densely sintered high strength individual core (B) with dental porcelain (A) by powder metallurgical manufacturing methods. The inner surface (I) of the core (B), which will fit against one or more prepared tooth surfaces (P) or artificial abutments is manufactured by forming a ceramic powder mixture against a surface of a body at which said surface is manufactured by registering the surfaces of the prepared teeth or artificial abutments and their mutual relationship with a three dimensional optical or mechanical reading method directly in the mouth or on a model in e.g. plaster after which the registered surfaces are reproduced in an enlarged size e.g. with a computer controlled milling machine at which the enlargement is calculated from the shrinkage of the ceramic material during sintering to full density and considering the gap for cement.

Inventors

  • 👤 Agneta Oden
  • 👤 Matts Andersson
  • 👤 Izidor Antonson

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-08 21:21
CPC Classifications
A; A61; A61C; A61C13/00; A61C13/0003; A61C13/0022

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 152 words
Method of manufacturing an artificial tooth restoration comprising a ceramic, densely sintered high strength individual core (B) with dental porcelain (A) by powder metallurgical manufacturing methods characterised in that the inner surface (I) of the core (B), which will fit against one or more prepared tooth surfaces (P) or artificial abutments are manufactured by forming a ceramic powder mixture against a surface of a body at which said surface is manufactured by registering the surfaces of the prepared teeth or artificial abutments and their mutual relationship with a three dimensional optical or mechanical reading method either directly in the mouth or on a model in e.g. plaster after which the registered surfaces are reproduced in an enlarged size e.g. with a computer controlled milling machine at which the enlargement is calculated from the shrinkage of the ceramic material during sintering to full density with adjustment of (I) considering desired gap for cement.
Claim 2
Dependent Claim 55 words
Method according to claim 1 characterised in that the core is manufactured by dry pressing a ceramic powder with a rubber tool X made from some viscous elastic material, close to desired size against the enlarged preparations K 2 , K 4 and K 6 made by milling of premade plaster, graphite or polymer blanks.
Claim 3
Dependent Claim 55 words
Method according to claim 2 characterised in that the rubber tool X is made by taking an impression of the body K 3 , K 5 or K 7 , manufactured from the enlarged preparations K 2 , K 4 or K 6 , with the addition of a shell of 1,5 - 3 mm.
Claim 4
Dependent Claim 68 words
Method according to claims 2 and 3 characterised in that after compacting of the ceramic powder against K 2 , K 4 or K 6 , K 2 , K 4 or K 6 are repositioned in the milling machine at which the outer contour of the core is milled to desired shape, whereupon the core is presintered on K 2 , K 4 or K 6 .
Claim 5
Dependent Claim 31 words
Method according to claims 2, 3 and 4 characterised in that the presintered core is removed from K 2 , K 4 or K 6 and is sintered to full density.
Claim 6
Dependent Claim 29 words
Method according to claims 1, 2, 3 and 4 characterised in that the core material consists of high strength, densely sintered ceramic material with a relative density of >99%.
Claim 7
Dependent Claim 48 words
Method according to claim 5 characterised in that the ceramic material in the core is based on one or more of the oxides Al 2 O 3 , TiO 2 , MgO, ZrO 2 or ZrO 2 with up to 25 mole% Y 2 O 3 or MgO.
Claim 8
Dependent Claim 25 words
Method according to claims 5 and 6 characterised in that the core material also comprises whiskers and/or particles of SiC, TiN, ZrO 2 and/or ZrN.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Maintenance schedule is calculated for granted US utility patents.

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag