US3660901A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Instrument of probing the length of a root canal of the tooth
Assignee: HAYASHI SHIKA SLO YK
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Filing: 1971-07-09
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Granted: 1972-05-09
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Expires: 1991-07-09
Abstract
Abstract An instrument for measuring the length of a root canal of the tooth provided with a transistor amplifier, at the input side thereof a probe needle for inserting into the root canal and at the output side thereof an oral mucous membrane conductor. Between the point of the probe needle and the oral mucous membrane conductor is electrically connected through a human body to form a circuit whereby the variations in low frequency oscillation due to feedback are delivered as oscillation sounds to the ear of the dentist. When the predetermined degree of oscillation sound comes to be audible, the length of the root canal is measured with an impregnated length of the probe.
Inventors
- 👤 Noboru Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:39
CPC Classifications
A; A61; A61C; A61C19/00; A61C19/04; A61C19/041; A61C5/00; A61C5/40; A61C5/44; A61B; A61B17/00; A61B2017/00017; A61B2017/00022; A61B2017/00026; A61B90/00; A61B90/03; A61B2090/033; A61B2090/036; A61B90/06; A61B2090/062; A61C19/042
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
154 words
An instrument for measuring the length of a root canal of the tooth comprising a transistor amplifier housing an electric cell, a probing part at the input side of the transistor amplifier consisting of a probe for measuring the length of the root canal, an insulated handle of the probe and a rubber piece slidable on the probe and at the output side of the transistor amplifier is connected through an ear-horn to an oral mucous membrane conductor, instrument characterized in that low frequency oscillation produced as the probe is inserted in the root canal is amplified in the transistor amplifier into oscillation sound and such low frequency oscillation sound becoming its peak indicates that the probe has reached the bottom apex of the root canal whereby at this moment with delivered sound to the earhorn, the length of the root canal is measured with the penetration of the probe into the root canal.
Claim 2
Dependent Claim
154 words
An instrument for measuring the length of a root canal of the tooth comprising a transistor amplifier housing an electric cell, a probing part at the input side of the transistor amplifier consisting of a probe for measuring the length of the root canal, an insulated handle of the probe and a rubber piece slidable on the probe and at the output side of the transistor amplifier is connected through an ear-horn to an oral mucous membrane conductor, instrument characterized in that low frequency oscillation produced as the probe is inserted in the root canal is amplified in the transistor amplifier into oscillation sound and such low frequency oscillation sound becoming its peak indicates that the probe has reached the bottom apex of the root canal whereby at this moment with delivered sound to the earhorn, the length of the root canal is measured with the penetration of the probe into the root canal.
References Cited (Backward Citations)
US3058225A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |