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US5217375A Expired / Lapsed US ⏱️ 0.0 years remaining

Artificial onlay tooth crowns and inlays

Assignee: Nobel Biocare AB
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Filing: 1991-08-30
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Granted: 1993-06-08
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Expires: 2011-08-30
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Abstract

Abstract The present invention relates to artificial onlay tooth crowns or inlays composed of a prefabricated core designed for preparations for onlay tooth crowns or inlays in natural teeth. The core is preferably fabricated from a high strength densely sintered ceramic material by copy milling from a negative reproduction from the prepared cavity to a compacted body or a presintered ceramic material. During the copy milling, the sintering shrinkage is considered by enlargement of the copy milled compacted body or the presintered body corresponding to the sintering shrinkage. The onlay tooth crowns and inlays are given the final shape by shaping the surfaces outside the cavity of the compacted or the presintered body. After the final sintering, the external surface can be shaped and a veneer material attached to the external surface of the core by, e.g., firing of dental porcelain. The manufacture of onlay tooth crowns or an inlay according to the method of the invention decreases essentially the manufacturing time for onlay tooth crowns and inlays and at the same time the strength and the accuracy to shape increase.

Inventors

  • 👤 Agneta E. Oden
  • 👤 Knut M. G. Andersson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 23:02
CPC Classifications
A; A61; A61C; A61C13/00; A61C13/0003; A61C5/00; A61C5/20; A61C5/30; A61C5/70; A61C5/73; A61C5/77

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 87 words
Artificial onlay tooth crown or inlay for fit into a prepared tooth cavity comprising a sintered core of a material which shrinks during sintering and a veneer overlaying at least part of the sintered core which does not fit into the said cavity, the boundary surface of the sintered core which fits into said cavity being formed by copy milling a negative reproduction cavity sized to adjust for shrinkage during subsequent sintering wherein the core is made of biocompatible ceramic material with a relative density of >95%.
Claim 2
Dependent Claim 87 words
Artificial onlay tooth crown or inlay for fit into a prepared tooth cavity comprising a sintered core of a material which shrinks during sintering and a veneer overlaying at least part of the sintered core which does not fit into the said cavity, the boundary surface of the sintered core which fits into said cavity being formed by copy milling a negative reproduction cavity sized to adjust for shrinkage during subsequent sintering wherein the core is made of biocompatible ceramic material with a relative density of >95%.
Claim 3
Dependent Claim 52 words
Artificial onlay tooth crown or inlay according to claim 1 wherein the ceramic material of the core comprises at least one of the oxides Al 2 O 3 , TiO 2 , MgO, ZrO 2 or ZrO 2 with up to 25 mole % Y 2 O 3 , MgO or CaO.
Claim 4
Dependent Claim 24 words
Artificial onlay tooth crown or inlay according to claim 2 wherein the ceramic material of the core comprises >50% Al 2 O 3 .
Claim 5
Dependent Claim 24 words
Artificial onlay tooth crown or inlay according to claim 3 wherein the ceramic material of the core comprises >85% Al 2 O 3 .
Claim 6
Dependent Claim 20 words
Artificial onlay tooth crown or inlay according to claim 3 wherein the ceramic material also comprises 3-12% ZrO 2 .
Claim 7
Dependent Claim 33 words
Artificial onlay tooth crown or inlay according to claim 1 wherein the core also comprises at least one of whiskers and particles of at least one of SiC, TiN, ZrO 2 and ZrN.
Claim 8
Dependent Claim 26 words
Artificial onlay tooth crown or inlay according to claim 6 wherein the core also comprises single crystal whiskers with a length to diameter ration >10 μm.
Claim 9
Dependent Claim 31 words
Artificial onlay tooth crown or inlay according to claim 6 wherein the core also comprises single crystal platelets with an approximate diameter of 5-50 μm and a thickness of 1-10 μm.
Claim 10
Dependent Claim 19 words
Artificial onlay tooth crown or inlay according to claim 1 wherein the copy milled core is a presintered body.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-06-07 1996-12-07 1997-06-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-06-07 2000-12-07 2001-06-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-06-07 2004-12-07 2005-06-08 $7700.00 Window Closed / Lapsed

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