Non-landed endodontic instrument and methods of making such endodontic instruments
First Claim
Patent Images
1. An apparatus comprising:
- an elongated shaft having a longitudinal axis, a working length extending along said longitudinal axis, and a plurality of longitudinal regions arranged about said longitudinal axis; and
a plurality of edges extending longitudinally along said working length and each distanced radially from said longitudinal axis, adjacent pairs of said plurality of edges adjoined by a corresponding one of said plurality of regions, at least one of said plurality of edges having a rake angle more negative than about −
30°
, at least one of said plurality of edges having a rake angle equal to or more positive than 0°
, and each of said plurality of edges defining a maximum radius measured at said axial location perpendicular to said longitudinal axis, wherein said plurality of regions are positioned radially inside an imaginary circle centered about said longitudinal axis at any axial location along the working length at which a cross-section may be taken perpendicular to the longitudinal axis, said imaginary circle has a radius measured perpendicular to said longitudinal axis equal to said maximum radius, and said plurality of edges are arranged such that each void area bounded by each of said plurality of regions and said imaginary circle is less than half the total area of said imaginary circle.
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Accused Products
Abstract
Endodontic instruments, including files, reamers, and condensers, that lack margins or radial lands. The instruments include at least one edge that does not provide significant tissue-cutting action and at least one cutting edge. The elimination of margins or radial lands reduces the surface area over which the root canal wall is contacted by the working length of the instrument.
82 Citations
31 Claims
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1. An apparatus comprising:
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an elongated shaft having a longitudinal axis, a working length extending along said longitudinal axis, and a plurality of longitudinal regions arranged about said longitudinal axis; and
a plurality of edges extending longitudinally along said working length and each distanced radially from said longitudinal axis, adjacent pairs of said plurality of edges adjoined by a corresponding one of said plurality of regions, at least one of said plurality of edges having a rake angle more negative than about −
30°
, at least one of said plurality of edges having a rake angle equal to or more positive than 0°
, and each of said plurality of edges defining a maximum radius measured at said axial location perpendicular to said longitudinal axis,wherein said plurality of regions are positioned radially inside an imaginary circle centered about said longitudinal axis at any axial location along the working length at which a cross-section may be taken perpendicular to the longitudinal axis, said imaginary circle has a radius measured perpendicular to said longitudinal axis equal to said maximum radius, and said plurality of edges are arranged such that each void area bounded by each of said plurality of regions and said imaginary circle is less than half the total area of said imaginary circle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A method of making an instrument from a workpiece with a longitudinal axis, comprising:
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forming a plurality of longitudinally-extending surfaces arranged circumferentially about the workpiece, each pair of adjacent surfaces meeting at a corresponding one of a plurality of first edges characterized by a rake angle more negative than about −
30° and
the workpiece free of lands after the longitudinally-extending surfaces are formed; and
forming one or more flutes in the workpiece, each of the flutes defining a second edge characterized by a rake angle equal to or more positive than 0°
. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31)
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Specification