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US4355978A Expired / Lapsed US ⏱️ 0.0 years remaining

Patrix for the production of a gold core for a prepared root-filled tooth

Assignee: Individual
•
Filing: 1980-10-16
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Granted: 1982-10-26
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Expires: 2000-10-16
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Abstract

Abstract In a method for the production of a gold core for a prepared root-filled tooth, the prepared root canal of the tooth is filled with a gasifiable setting impression material. A prefabricated core patrix, preferably of plastic, which consists of a core portion and a dowel portion, is inserted in the impression material which is allowed to set around the dowel portion for the formation of a core pattern. The core pattern is removed from the tooth and is embedded in a mold material which is heated for the gasification of the pattern, whereupon a gold core is cast in the mold formed after the gasification of the pattern. A core patrix for the production of a gold core for a prepared root-filled tooth is made as a single piece and consists of a core portion and a dowel portion which has a substantially smaller transverse dimension than the prepared root canal of the tooth. The core patrix is preformed and consists of a gasifiable material. The core portion serves as a pattern for a gold core intended for the fixation of a tooth crown and the dowel portion is insertable in the root canal of the tooth in order there to form a fixation for a gasifiable setting impression material applied to the root canal, the core patrix and the set impression material applied to the dowel portion being usable as a casting pattern for the gold core.

Inventors

  • 👤 Dan W. Ericson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 10:10
CPC Classifications
A; A61; A61C; A61C5/00; A61C5/70; A61C13/00; A61C13/225; A61C13/30; A61C13/01; A61C13/04; A61C5/77; A61C9/00

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 145 words
A core patrix for the production of a gold core for a prepared root-filled tooth having a root canal, said core patrix comprising: a single piece made from a gasifiable material, said single piece having a core portion and a dowel portion, said core portion corresponding to and defining the shape of the upper part of the finished gold core, said dowel portion having a substantially smaller thickness than the root canal, said patrix, after the insertion of said dowel portion in a root canal filled with a gasifiable impression material and after setting of said impression material on said dowel portion, together with said impression material will form a core pattern from which the gold core is cast, said core portion including a recessed portion facing said dowel portion and the root canal, said recessed portion confining said impression material to said dowel portion.
Claim 2
Dependent Claim 145 words
A core patrix for the production of a gold core for a prepared root-filled tooth having a root canal, said core patrix comprising: a single piece made from a gasifiable material, said single piece having a core portion and a dowel portion, said core portion corresponding to and defining the shape of the upper part of the finished gold core, said dowel portion having a substantially smaller thickness than the root canal, said patrix, after the insertion of said dowel portion in a root canal filled with a gasifiable impression material and after setting of said impression material on said dowel portion, together with said impression material will form a core pattern from which the gold core is cast, said core portion including a recessed portion facing said dowel portion and the root canal, said recessed portion confining said impression material to said dowel portion.

References Cited (Backward Citations)

US751592A Cited
US641930A Cited
US731594A Cited
US983579A Cited
US907949A Cited
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US1140539A Cited
US1397067A Cited
US2536669A Cited
FR1131191A Cited
US3949476A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1985-10-25 1986-04-26 1986-10-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1989-10-25 1990-04-26 1990-10-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1993-10-25 1994-04-26 1994-10-26 $7700.00 Window Closed / Lapsed

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