Patent US4332561A successfully refreshed from Google Patents.
US4332561A
Expired / Lapsed
US
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Dental file
Assignee: Dentsply Sirona Inc
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Filing: 1981-05-14
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Granted: 1982-06-01
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Expires: 2001-05-14
Abstract
Abstract A dental file is disclosed which is particularly useful in endodontia for removing dead or damaged tissue from a curved tooth root canal. The file has a flexible tapered shank which has a cutting surface on its periphery and a pilot projecting from the tapered end of the file for guiding the shank along the curved root canal preventing the cutting surface near the end of the shank from gouging into the wall of the curved root canal or penetrating too far through the apical foramen of the root canal.
Inventors
- 👤 John T. McSpadden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:40
CPC Classifications
A; A61; A61C; A61C5/00; A61C5/40; A61C5/42; A61C1/00; A61C1/0007; A61C1/0015; A61C1/003
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
133 words
A set of dental files comprising individual files each having a shank tapered along at least part of its length, having cutting means formed in at least a portion of the tapered length of the shank, the files of the set having tapered shanks which incrementally increase in diameter from one file to the next larger file of the set, and each file of the set comprises a generally cylindrical smooth walled pilot having a generally non-cutting end formed at and projecting coaxially from the tapered end of the shank, the diameter of said pilot being substantially the same for all files of the set and corresponds to a pilot dimensioned for the smallest file of the set said pilot having a length from greater than about 1.0 mm to about 3.0 mm.
Claim 2
Dependent Claim
133 words
A set of dental files comprising individual files each having a shank tapered along at least part of its length, having cutting means formed in at least a portion of the tapered length of the shank, the files of the set having tapered shanks which incrementally increase in diameter from one file to the next larger file of the set, and each file of the set comprises a generally cylindrical smooth walled pilot having a generally non-cutting end formed at and projecting coaxially from the tapered end of the shank, the diameter of said pilot being substantially the same for all files of the set and corresponds to a pilot dimensioned for the smallest file of the set said pilot having a length from greater than about 1.0 mm to about 3.0 mm.
Claim 3
Dependent Claim
47 words
The set of dental files of claim 1, wherein the pilot of each file of the set has a smaller diameter than the diameter of the tapered shank of the smallest file of the set measured at about 1 mm above the tapered end of the shank.
Claim 4
Dependent Claim
189 words
The set of dental files of claim 1, comprising: a first plurality of dental files having said tapered shanks which incrementally increase in diameter from one file to the next larger file of the first plurality of files, each file of said first plurality of files having a pilot of substantially the same diameter and corresponding to the pilot dimensioned for the smallest file of the set; and, a second plurality of dental files having said tapered shanks which incrementally increase in diameter from one file to the next larger file of the second plurality of files, the smallest file of said second plurality of files having a shank diameter larger than the largest file of said first plurality of files, each file of said second plurality of files having a pilot of substantially the same diameter as the rest of the files of said second plurality of files, said diameter being smaller than the diameter of the shank of the largest dental file of said first plurality of files as measured about 1 mm from the tapered end of the largest file of said first plurality of files.
Claim 5
Dependent Claim
42 words
The set of dental files of claim 3, wherein the length of said pilot of each file of said second plurality of files is substantially the same as the length of said pilot of each file of said first plurality of files.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-31 | 1985-11-30 | 1986-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-31 | 1989-11-30 | 1990-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-31 | 1993-11-30 | 1994-06-01 | $7700.00 | Window Closed / Lapsed |