Patent US2979238A successfully refreshed from Google Patents.
Patent US4268253A successfully refreshed from Google Patents.
US4268253A
Expired / Lapsed
US
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Dowel post for dental and medical prosthetic devices
Assignee: TURNER CHRISTOPHER H
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Filing: 1979-12-26
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Granted: 1981-05-19
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Expires: 1999-12-26
Abstract
Abstract A dowel post for securing dental and medical prostheses is provided having improved retention when cemented in a parallel-sided blind hole, and which reduces build-up of hydrostatic pressure ahead of the post as it is inserted. The dowel post comprises a head on which said prosthesis is formed or mounted and a shaft extending downwardly therefrom having a channel formed therealong providing a flow path for the cement. The channel is formed by one or more and preferably four or five helical concave flutes wound about the axis of the post at a pitch angle to the axis of 70° or less and preferably at about 45°.
Inventors
- 👤 Michael J. Gross
- 👤 Christopher H. Turner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:48
CPC Classifications
A; A61; A61C; A61C13/00; A61C13/225; A61C13/30
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
116 words
A dowel post for anchoring a dental or medical prosthetic device comprising a head on which said device may be formed or mounted and a shaft extending therefrom for insertion into a previously prepared parallel-sided blind hole, and secured therein by a cement, wherein said shaft is of substantially constant diameter along its length and is provided with a plurality of concave flutes helically intertwined about the axis of said shaft and co-extending substantially along the length thereof at a pitch angle of 70° or less to the axis of the shaft, said concave flutes being contiguous around the circumference of the shaft, and providing said shaft with a substantially uniform polygonal section along its length.
Claim 2
Dependent Claim
116 words
A dowel post for anchoring a dental or medical prosthetic device comprising a head on which said device may be formed or mounted and a shaft extending therefrom for insertion into a previously prepared parallel-sided blind hole, and secured therein by a cement, wherein said shaft is of substantially constant diameter along its length and is provided with a plurality of concave flutes helically intertwined about the axis of said shaft and co-extending substantially along the length thereof at a pitch angle of 70° or less to the axis of the shaft, said concave flutes being contiguous around the circumference of the shaft, and providing said shaft with a substantially uniform polygonal section along its length.
Claim 3
Dependent Claim
26 words
A dowel post according to claim 1, wherein: said flute(s) is or are at a pitch angle of about 45° to the axis of the shaft.
Claim 4
Dependent Claim
23 words
A dowel post according to claim 2 having four helical flutes equispaced around the shaft and coextending along the length of the shaft.
Claim 5
Dependent Claim
21 words
A dental crown comprising: a dowel post as claimed in claim 1 and a crown member mounted on the head thereof.
Claim 6
Dependent Claim
32 words
A medical prosthetic device in the form of an artificial joint comprising: a dowel post as claimed in claim 1 and an artificial joint member formed or mounted on the head thereof.
Claim 7
Dependent Claim
139 words
In a method of crowning a tooth root which comprises inserting a dowel post into a previously prepared, parallel-sided blind hole in the tooth root and securing the dowel post therein by means of a cement, the exposed end of the dowel post providing a point of attachment for the tooth crown, the improvement which comprises inserting into a cement-lined blind hole a dowel post having a shaft of substantially constant diameter along its length and provided on its surface with a plurality of concave flutes helically intertwined about the axis of said shaft and co-extending substantially along the length thereof at a pitch angle of 70° or less to the axis of the shaft, said concave flutes being contiguous around the circumference of the shaft, and providing said shaft with a substantially uniform polygonal section along its length.
Claim 8
Dependent Claim
139 words
In a method of crowning a tooth root which comprises inserting a dowel post into a previously prepared, parallel-sided blind hole in the tooth root and securing the dowel post therein by means of a cement, the exposed end of the dowel post providing a point of attachment for the tooth crown, the improvement which comprises inserting into a cement-lined blind hole a dowel post having a shaft of substantially constant diameter along its length and provided on its surface with a plurality of concave flutes helically intertwined about the axis of said shaft and co-extending substantially along the length thereof at a pitch angle of 70° or less to the axis of the shaft, said concave flutes being contiguous around the circumference of the shaft, and providing said shaft with a substantially uniform polygonal section along its length.
References Cited (Backward Citations)
US1307446A
Cited
US659196A
Cited
US2536669A
Cited
FR1013516A
Cited
US3364575A
Cited
US3499222A
Cited
US3672058A
Cited
US3928915A
Cited
DE2255916A1
Cited
US4103422A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-18 | 1984-11-17 | 1985-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-18 | 1988-11-17 | 1989-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-18 | 1992-11-17 | 1993-05-19 | $7700.00 | Window Closed / Lapsed |