Patent US4932870A successfully refreshed from Google Patents.
US4932870A
Expired / Lapsed
US
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Dental post and method for making the same
Assignee: G H ACQUISITION CORP A CORP OF
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Filing: 1988-08-18
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Granted: 1990-06-12
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Expires: 2008-08-18
Abstract
Abstract A dental post for retaining a dental restoration onto a tooth stub and a method for making dental post. The dental post includes a cylindrical body portion and a head portion which extends outwardly from the body portion. The body portion is inserted in a bore in the tooth and secured therein by cement. To improve cement retaining capacity of the dental post, there are provided on the body portion non-continuous raised portions, spaced by wide open gaps to retain large segments of thick segments of cement. The overall portion of the gap area surface is greater than that of the land area surface.
Inventors
- 👤 Alan N. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:52
CPC Classifications
A; A61; A61C; A61C13/00; A61C13/0003; A61C13/225; A61C13/30
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
186 words
A dental post for retaining a dental restoration in secured position, the dental post being inserted in a bore of a tooth stub, which bore is to be filled with cement, the dental post comprising: an elongated substantially cylindrical body portion having an outer surface; a head portion extending from said body portion for projecting outwardly from the tooth stub to support thereon a dental restoration when said body portion is inserted into the bore of the tooth stub; and cement retention means formed on said outer surface; said outer surface including a raised area portion and a groove area portion which constitutes said cement retention means, wherein a ratio between said groove area portion and said raised area portion is greater than 50%, said raised portion and said groove area portion being formed by two threads provided on said outer surface and crossing each other, said each thread being open at each end thereof so that groove area portion being a continuous non-interrupted area to permit air to escape from the bore of the tooth stub when said body portion is cemented in said bore.
Claim 2
Dependent Claim
186 words
A dental post for retaining a dental restoration in secured position, the dental post being inserted in a bore of a tooth stub, which bore is to be filled with cement, the dental post comprising: an elongated substantially cylindrical body portion having an outer surface; a head portion extending from said body portion for projecting outwardly from the tooth stub to support thereon a dental restoration when said body portion is inserted into the bore of the tooth stub; and cement retention means formed on said outer surface; said outer surface including a raised area portion and a groove area portion which constitutes said cement retention means, wherein a ratio between said groove area portion and said raised area portion is greater than 50%, said raised portion and said groove area portion being formed by two threads provided on said outer surface and crossing each other, said each thread being open at each end thereof so that groove area portion being a continuous non-interrupted area to permit air to escape from the bore of the tooth stub when said body portion is cemented in said bore.
Claim 3
Dependent Claim
14 words
A dental post as in claim 1, wherein said ratio is 60 to 40.
Claim 4
Dependent Claim
30 words
A dental post of claim 1, wherein a pitch of each of said threads is adjustable to adjust said ratio between said groove area portion and said raised area portion.
Claim 5
Dependent Claim
28 words
A dental post of claim 1, wherein a depth of each thread is adjustable to adjust said ratio between said groove area portion and said raised area portion.
Claim 6
Dependent Claim
45 words
A dental post of claim 1, wherein said crossing threads form lands spaced from each other to enclose therebetween at least one vent to further assist air in escaping from the bore of the tooth stub when said body portion is cemented in said bore.
Claim 7
Dependent Claim
15 words
A dental post as in claim 5, wherein said lands are of substantially rhombic shape.
Claim 8
Dependent Claim
23 words
A dental post as in claim 5, wherein two vent paths extending approximately axially on said body portion are formed between said lands.
Claim 9
Dependent Claim
16 words
A dental post as in claim 1, wherein said head portion includes a flattened tang member.
Claim 10
Dependent Claim
16 words
A dental post as in claim 1, wherein said head portion is of substantially oval cross-section.
Claim 11
Dependent Claim
13 words
A dental post as in claim 1, wherein said head portion is flattened.
Claim 12
Dependent Claim
23 words
A dental post as in claim 1, wherein said head portion has a configuration corresponding to an anatomical shape of the dental restoration.
Claim 13
Dependent Claim
13 words
A dental post as in claim 1, wherein said body portion is stepped.
Claim 14
Independent Claim
108 words
A method of making dental posts of the type having an elongated substantially cylindrical body portion and a head portion for supporting a dental restoration and extending outwardly from the body portion which is to be secured in a bore of a tooth stub by cement, the method comprising the steps of forming on an outer surface of the body portion two crossing threads each being open at each end thereof which form grooves for retaining cement, so that a continuous, non-interrupted groove area portion is formed on said outer surface and an overall groove area portion constitutes on said outer surface more than 50% of the surface.
Claim 15
Independent Claim
108 words
A method of making dental posts of the type having an elongated substantially cylindrical body portion and a head portion for supporting a dental restoration and extending outwardly from the body portion which is to be secured in a bore of a tooth stub by cement, the method comprising the steps of forming on an outer surface of the body portion two crossing threads each being open at each end thereof which form grooves for retaining cement, so that a continuous, non-interrupted groove area portion is formed on said outer surface and an overall groove area portion constitutes on said outer surface more than 50% of the surface.
Claim 16
Dependent Claim
16 words
A method as in claim 13, wherein a pitch of said crossing threads can be altered.
Claim 17
Dependent Claim
16 words
A method as in claim 13, wherein a depth of said crossing threads can be altered.
Claim 18
Dependent Claim
15 words
A method as in claim 13, wherein said crossing threads are formed by thread rolling.
Claim 19
Dependent Claim
14 words
A method as in claim 13, wherein said crossing threads are formed by casting.
Claim 20
Dependent Claim
15 words
A method as in claim 13, wherein said crossing threads are formed by cold forming.
Claim 21
Dependent Claim
14 words
A method as in claim 13, wherein said crossing threads are formed by cutters.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-11 | 1993-12-11 | 1994-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-11 | 1997-12-11 | 1998-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-11 | 2001-12-11 | 2002-06-12 | $7700.00 | Window Closed / Lapsed |