U.S. patent application number 10/459896 was filed with the patent office on 2003-11-06 for flexible endodontic syringe.
Invention is credited to Nance, Robert Scott.
Application Number | 20030207231 10/459896 |
Document ID | / |
Family ID | 24356102 |
Filed Date | 2003-11-06 |
United States Patent
Application |
20030207231 |
Kind Code |
A1 |
Nance, Robert Scott |
November 6, 2003 |
Flexible endodontic syringe
Abstract
A flexible endodontic syringe for use in performing root canal
therapy on a tooth and that is particularly useful for irrigating a
root canal possessing a non-linear central axis is presented. The
instrument comprises an elongate shank or needle having an enclosed
axial channel or lumen. The shank or needle possesses a flexibility
sufficient to substantially traverse the entire length of a root
canal. A method for irrigating a root canal is also disclosed.
Inventors: |
Nance, Robert Scott;
(Statesville, NC) |
Correspondence
Address: |
ALSTON & BIRD LLP
BANK OF AMERICA PLAZA
101 SOUTH TRYON STREET, SUITE 4000
CHARLOTTE
NC
28280-4000
US
|
Family ID: |
24356102 |
Appl. No.: |
10/459896 |
Filed: |
June 12, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10459896 |
Jun 12, 2003 |
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09588981 |
Jun 7, 2000 |
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Current U.S.
Class: |
433/81 ;
433/224 |
Current CPC
Class: |
A61C 5/40 20170201 |
Class at
Publication: |
433/81 ;
433/224 |
International
Class: |
A61C 005/02 |
Claims
1. An endodontic instrument adapted for use in performing root
canal therapy on a tooth and that is particularly useful for
irrigating a root canal possessing a nonlinear central axis, the
instrument comprising: an elongate shank having a first end and an
opposite second end; an enclosed axial channel extending the length
of the shank for providing fluid communication between said first
end and said second end for delivering fluids to areas external to
said second end of said shank; and at least one radial orifice
positioned adjacent said second end for providing radial dispersion
of fluid from said orifice; said shank being sufficiently flexible
to substantially traverse the entire length of a root canal having
a non-linear central axis and position said second end of said
shank adjacent the distal end of the curved root canal and the
apical foramina.
2. The endodontic instrument of claim 1 wherein said second end of
the shank comprises a blunt end surface.
3. The endodontic instrument of claim 1 wherein said orifice
comprises at least one hole situated along the perimeter of said
shank.
4. The endodontic instrument of claim 1 wherein said orifice
comprises a semi-cylindrical structure at the terminus of said
second end of said shank.
5. The endodontic instrument of claim 1 further comprising a
plurality of axially spaced apart depth calibration markings
positioned along the shank.
6. The endodontic instrument of claim 1 wherein the shank of said
instrument comprises an alloy comprising nickel and titanium.
7. The endodontic instrument of claim 6 wherein the shank of said
instrument comprises an alloy comprising at least about 30%
titanium and at least about 50% nickel.
8. The endodontic instrument of claim 1 wherein the shank of said
instrument is tapered at an included angle of between about 1/2 and
about 5 degrees.
9. The endodontic instrument of claim 1 further comprising a
fitting mounted at said first end of the shank, said fitting for
establishing fluid communication between said enclosed axial
channel and a fluid reservoir.
10. The endodontic instrument of claim 9 further comprising a fluid
reservoir in fluid communication with said enclosed axial
channel.
11. An endodontic irrigation syringe comprising: a reservoir for
retaining a fluid; a needle in fluid communication with said
reservoir, said needle comprising an elongate shank having a first
end and an opposite second end and an enclosed axial channel
extending the length of the shank for providing fluid communication
between said reservoir and said second end and for delivering
fluids to areas external to said second end of said shank, said
shank being sufficiently flexible to substantially traverse the
entire length of a root canal having a non-linear central axis and
position said second end of said shank adjacent the distal end of
the curved root canal and the apical foramina; at least one radial
orifice positioned adjacent said second end for providing radial
dispersion of fluid from said orifice; and means for dispensing a
fluid from said reservoir to said channel of said needle.
12. The endodontic irrigation syringe of claim 11 wherein said
second end of the shank comprises a blunt end surface.
13. The endodontic irrigation syringe of claim 11 wherein said
orifice comprises at least one hole situated along the perimeter of
said shank.
14. The endodontic irrigation syringe of claim 11 wherein said
orifice comprises a semi-cylindrical structure at the terminus of
said second end of said shank positioned along the shank.
15. The endodontic irrigation syringe of claim 11 wherein the shank
of said needle comprises an alloy comprising nickel and
titanium.
16. The endodontic irrigation syringe of claim 15 wherein the shank
of said needle comprises an alloy comprising at least about 30%
titanium and at least about 50% nickel.
17. The endodontic irrigation syringe of claim 11 wherein the shank
of said needle is tapered at an included angle of between about 1/2
and about 5 degrees.
18. A method for irrigating a root canal possessing a non-linear
central axis, the method comprising: transferring a fluid by way of
a needle from the crown of the tooth along the non-linear central
axis of the root canal to a discharge point adjacent the apical
foramina and thereafter discharging the fluid from an orifice at
the distal end of the needle such that a portion of the fluid is
discharged substantially perpendicularly to the openings of the
side canals and tubules extending from the main root canal and
adjacent the apical foramina.
19. A method according to claim 18 in which the fluid comprises at
least one fluid selected from the group consisting of disinfecting
agents and chelating agents.
20. A method according to claim 19 wherein the disinfecting agent
is sodium hypochlorite and the chelating agent is EDTA.
21. A method according to claim 18 wherein said orifice comprises a
semi-cylindrical structure at the terminus of the distal end of the
needle.
22. A method according to claim 18 further comprising adjusting the
depth of insertion by measuring a plurality of axially spaced apart
depth calibration markings positioned along the needle.
23. A method according to claim 18 wherein the needle comprises an
alloy comprising nickel and titanium.
24. A method according to claim 23 wherein the needle comprises an
alloy comprising at least about 30% titanium and at least about 50%
nickel.
25. A method according to claim 18 wherein the needle is tapered at
an included angle of between about 1/2 and about 5 degrees.
26. A method for irrigating the distal end of a root canal
possessing a nonlinear central axis, the method comprising:
inserting an elongate, hollow and flexible shank having a first end
and an opposite second end into a root canal along a path that
generally follows the nonlinear central axis of the root canal and
positioning the second end of the shank adjacent the distal end of
the root canal and the apical foramina; and injecting an irrigation
fluid into the distal end of the root canal through an orifice
adjacent the second end of the shank whereby at least a portion of
the irrigation fluid impacts the sidewall of the root canal at an
angle that is substantially perpendicular to the central axis of
the root canal.
27. A method according to claim 26 in which the irrigating fluid is
selected from the group comprising disinfecting agents and
chelating agents.
28. A method according to claim 26 wherein said second end of the
shank comprises a blunt end surface.
29. A method according to claim 26 wherein said orifice comprises
at least one hole situated along the perimeter of the shank.
30. A method according to claim 26 wherein said orifice comprises a
semi-cylindrical structure at the terminus of the second end of the
shank.
31. A method according to claim 26 further comprising adjusting the
depth of insertion by measuring a plurality of axially spaced apart
depth calibration markings positioned along the shank.
32. A method according to claim 26 wherein the shank comprises an
alloy comprising nickel and titanium.
33. A method according to claim 32 wherein the shank comprises an
alloy comprising at least about 30% titanium and at least about 50%
nickel.
34. A method according to claim 26 wherein the shank is tapered at
an included angle of between about 1/2 and about 5 degrees.
35. A Luer type connector having a first end and a second end, said
first and second ends being separated by an intermediate portion,
said intermediate portion being substantially cylindrical and
nonlinear and forming an angle between said first end and said
second end and having a lumen extending its length providing fluid
communication between said first end and said second end.
36. A connector according to claim 35 wherein the distance between
the origin of said angle and said first end is greater than the
distance between the origin of said angle and said second end.
37. A connector according to claim 35 wherein said connector is
made of a polymer.
38. A syringe comprising: a hollow, axially elongated barrel; a
needle; a removable connector attached to said barrel adjacent a
distal end thereof said connector comprising a first end removably
attached to said distal end of said barrel and a second end
attached to said needle, said first and second ends being separated
by an intermediate portion, said intermediate portion being
non-linear and forming an angle between said first end and said
second end, said connector further comprising a lumen extending the
length thereof and providing fluid communication between said
barrel and said needle; said needle comprising an elongate shank
having a first end and an opposite second end and an enclosed axial
channel extending the length of the shank for providing fluid
communication between said barrel and said second end of said shank
and for delivering fluids to areas external to said second end of
said shank, said shank being sufficiently flexible to substantially
traverse the entire length of a root canal having a non-linear
central axis and position said second end of said shank adjacent
the distal end of the curved root canal and the apical foramina; at
least one radial orifice positioned adjacent said second end of
said shank for providing radial dispersion of fluid from said
orifice; and means for dispensing a fluid from said barrel to said
channel of said needle.
39. The syringe of claim 38 wherein said second end of said shank
comprises a blunt end surface.
40. The syringe of claim 38 wherein said connector is removable
from said barrel in response to the application of a torque.
41. The syringe of claim 38 wherein said connector is removable
from said barrel in response to the application of a linear
force.
42. The syringe of claim 38 wherein said shank of said needle
comprises an alloy comprising nickel and titanium.
43. The syringe of claim 43 wherein the shank of said needle
comprises an alloy comprising at least about 30% titanium and at
least about 50% nickel.
44. The syringe of claim 38 wherein said angle is selected from the
group consisting of obtuse and right angles.
Description
FIELD OF THE INVENTION
[0001] The invention is an apparatus and method for use in dental
applications. In particular, the invention is an apparatus and
method for use in endodontic or root canal procedures.
BACKGROUND
[0002] Endodontics or root canal therapy is a well-known dental
procedure wherein the crown of a diseased tooth is opened to permit
the canal (or canals) of the tooth to be cleaned and filled. In
general terms, a root canal proceeds as follows. The crown of the
tooth is opened to expose the root canal. Typical root canals have
a non-linear central axis, i.e., they are curved, and the curve of
the canal can be quite severe. During an endodontic procedure, a
series of very delicate, flexible, rotary driven or finger-held
instruments or files are used to extirpate or clean out and shape
the root canal. These files typically possess contoured or rough
outer surfaces to enable the endodontist to break up and loosen
tissue as well as remove infected dentin from the canal walls
within the root canal. Examples of such files are discussed in U.S.
Pat. No. 5,713,736 to Heath et al. The endodontist usually rotates
and reciprocates the file to bring loose tissue and debris out of
the root canal.
[0003] The files, however, are incapable of removing all of the
necessary tissue and debris, especially tissue and debris trapped
in the smaller lateral canals extending off the main canal. Thus,
Endodontists remove this tissue and debris by injecting a fluid
(typically a disinfecting agent or chelating agent) into the canal
to irrigate the canal. The typical disinfecting fluid is a dilute
solution of sodium hypochlorite. Ethylenediaminetetraacetic acid
(EDTA) is a typical chelating agent.
[0004] Fluid injection is accomplished by means of a hollow needle
or syringe. As used herein, the term needle will generally refer to
the elongate, typically metal shank traditionally associated with
medical injections. The term needle and shank may be used
interchangeably herein unless the context of the description or
claims requires otherwise. The term syringe is used to encompass
both a needle and other elements necessary to discharge a fluid
from a needle such as a fluid reservoir and plunger. The injection
and removal of the solution is referred to as "irrigating" or
"aspirating" the canal.
[0005] After irrigation, the cleaned, disinfected and vacant root
canal is then obturated or filled, typically with a waxy, rubbery
compound known as gutta percha. A set of rod-like pluggers similar
to the files used to extirpate the canal force the gutta percha
down into the canal. After the canal is filled, the crown of the
tooth is repaired thereby completing the procedure.
[0006] The non-linear structure of root canals presents several
problems for endodontists. The canal must be cleaned and
disinfected but the integrity of the canal must be maintained. If a
stiff file or plugger is used, the distal end of the tool may
pierce the sidewall of the canal and destroy the tooth. If a
flexible file or plugger is used, it must maintain enough rigidity
to accomplish the task of removing or inserting material. For many
years, a suitable material for making files and pluggers did not
exist and endodontists compensated by creating larger entry holes
in crowns and using the best materials at hand.
[0007] In the late 1980's and early 1990's, nickel-titanium alloys
possessing superelastic and suitable shape memory properties became
available. Instrument companies began manufacturing files and
pluggers made from these alloys. The nickel-titanium files and
pluggers allowed the endodontist to reach the bottom of the root
canal without excessive risk of puncturing the side of the
canal.
[0008] Although nickel-titanium files and pluggers improved
portions of the root canal procedure, problems remain with respect
to the irrigation, aspiration and disinfection of the canal.
Presently, the irrigation solutions used to clean, disinfect, and
remove debris in the canal are delivered using rigid irrigation
needles. These needles are typically made of stainless steel and
possess blunt ends. The distal end of the needle typically
possesses slits or other structural components to ensure that the
solution is distributed both axially and radially within the
canal.
[0009] The rigid nature of a stainless steel irrigation syringe
prevents an endodontist from reaching the bottom of a root canal
with a syringe. Accordingly, an endodontist cannot directly
irrigate the distal end of the root canal adjacent the apical
foramina or a large portion of the complex network of fine lateral
fissures, tubules and canals that extend from the main canal. The
bottom of the root canal and the fine web of fissures may act as a
breeding ground for bacteria that may later lead to a serious
infection resulting in failure of the endodontic treatment and loss
of the tooth. Using current syringes, the endodontist must try to
force the solution, through exertion of hydraulic pressure, to the
bottom of the canal and into the fine fissures and canals or make
geometric adjustments to the insertion angle. If too much pressure
is exerted, the solution may exit the root canal seriously damaging
underlying tissue. Geometric adjustments to the insertion angle to
extend the insertion distance may damage the crown. In short,
complete irrigation and proper disinfection of the canal cannot be
ensured using known instruments.
[0010] Accordingly, a need exists for an endodontic instrument that
allows an endodontist to inject irrigation, disinfecting, and
debris removal solutions adjacent the distal end of a root canal.
Such an instrument must also be compatible with the physical and
geometric constraints imposed by structure of the root canal.
OBJECT AND SUMMARY OF THE INVENTION
[0011] An object of the present invention is to provide an improved
endodontic instrument and method for use in root canal therapy. A
further object of the invention is to provide an improved
endodontic instrument and method for irrigating and disinfecting
root canals during endodontic procedures. A still further object of
the invention is to provide an improved endodontic instrument and
method that allows for the injection of irrigating and disinfecting
solutions at the distal end of a root canal adjacent the apical
foramina.
[0012] The above and other objects and advantages of the present
invention are achieved in the embodiments illustrated herein by the
provision of an endodontic instrument adapted for use in performing
root canal therapy on a tooth. The endodontic instrument according
to the invention is particularly useful for irrigating a root canal
possessing a non-linear central axis. In one embodiment, the
endodontic instrument according to the invention comprises an
elongate shank having a first end and an opposite second end and an
enclosed axial channel extending the length of the shank for
providing fluid communication between the first end and the second
end. The enclosed axial channel delivers fluids to areas external
to the second end of the shank (i.e., the wall of a root canal).
The instrument also comprises at least one radial orifice
positioned adjacent the second end for providing radial dispersion
of fluid from the orifice. The instrument is further defined as
possessing a shank having a flexibility sufficient to substantially
traverse the entire length of a root canal having a non-linear
central axis and position the second end of the shank adjacent the
distal end of the curved root canal and the apical foramina.
[0013] In a further embodiment, the invention is a method for
irrigating a root canal possessing a non-linear central axis. The
method according to the invention comprises transferring a fluid by
way of a needle from the crown of the tooth along the non-linear
central axis of a root canal to a discharge point adjacent the
apical foramina. Thereafter, the method comprises discharging a
fluid from an orifice at the distal end of the needle such that a
portion of the fluid is discharged along a vector that is
substantially perpendicular to the openings of the side canals and
tubules extending from the main root canal and adjacent the apical
foramina.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] This invention may be better understood and its numerous
objects and advantages will become apparent to those skilled in the
art by reference to the accompanying drawings in which:
[0015] FIG. 1 is a perspective view of an endodontic irrigation
needle in accordance with the invention.
[0016] FIG. 2 is a schematic representation of the irrigation of a
root canal in accordance with one embodiment of the invention.
[0017] FIG. 3 is a perspective view of one end of a needle.
[0018] FIG. 4 is a cross-sectional view of a needle.
[0019] FIG. 5 is a cross-sectional view of a distal end of a
needle.
[0020] FIG. 6 is a cross-sectional view of a needle.
[0021] FIG. 7 is a cross-sectional view of a distal end of a
needle.
[0022] FIG. 8 is a cross-sectional view of a needle.
[0023] FIG. 9 is a cross-sectional view of a distal end of a
needle.
[0024] FIG. 10 is a side view of a syringe according to the
invention.
DETAILED DESCRIPTION
[0025] One embodiment of the claimed invention is an endodontic
instrument adapted for use in performing root canal therapy on a
tooth. The claimed invention is particularly useful in irrigating a
root canal possessing a non-linear central axis. Referring now to
FIG. 1, the endodontic instrument comprises an elongate shank 10
having a first end 12 and an opposite second end 14. As shown in
FIG. 3, the second end of the shank 14 is preferably rounded or
blunt to prevent unwanted breaches of the wall of the root canal.
The shape of the second end of the shank, however, may be angled or
pointed if desired or needed for a particular application.
[0026] An enclosed axial channel or lumen 16, such as those
utilized in hypodermic needles, extends the length of the shank. An
enclosed axial channel or lumen 16 is shown schematically by dotted
lines in FIG. 4 and in cross-section in FIGS. 5 and 7. The enclosed
axial channel 16 provides fluid communication (i.e., a pathway for
fluid transfer) between the first end 12 of the shank and the
second end 14 of the shank and to areas external to the second end
of the shank (i.e., the root canal).
[0027] At least one radial orifice 18 is positioned adjacent the
second end 14 of the shank. As used herein, the term "radial
orifice" is utilized to convey the fact that the instrument
according to the invention delivers fluid in a manner distinctly
different from traditional needles or syringes used in other
medical procedures. Whereas most needles eject fluid along a path
aligned with the needle's elongate axis, the instrument according
to the invention is designed to eject fluid or cause fluid to eject
at an angle oblique from or perpendicular to the shank's elongate
axis as shown in FIG. 3. The radial dispersion of the fluid is
accomplished by creating at least one orifice having at least one
cross-sectional plane that is oblique or parallel to the elongate
axis of the shank. Such orifices are familiar to those skilled in
the art. Further, it is to be understood that the orifices shown in
the figures are representative and are not intended to limit the
scope of the invention.
[0028] Referring now to FIGS. 3-7, the shank 10 possesses several
orifices 18 adjacent the second end 14 of the shank. Each orifice
18 is a hole situated along the perimeter of the shank 10. Each
orifice 18 or hole possesses at least one cross-sectional plane
that is oblique or parallel to the elongate axis of the shank.
[0029] Alternatively, radial dispersion is accomplished by removing
a portion of the shanks wall at the terminus of the second end 14
of the shank as shown in FIG. 8. The removal of the wall creates a
semi-cylindrical opening 20 at the terminus of the second end 14.
The semi-cylindrical opening allows at least a portion of the
exiting fluid to exit at an angle oblique to the shank's elongate
axis.
[0030] The dispersion of the fluid at an angle oblique or
perpendicular to the shank's elongate axis is important for a
number of reasons. For example, a fine web of small canals and
tubules extends in all directions from the main root canal. Known
needles are incapable of ejecting irrigating or disinfecting fluid
directly at the wall of the root canal at all points along the
curve of the canal. Currently, endodontists must create a hydraulic
head in the root canal to force the fluid to the bottom of the
canal and into the smaller branch canals. As discussed previously,
creating excessive pressures inside the root canal risks damaging
the root canal and should be avoided.
[0031] Referring again to FIG. 4, the shank 10 preferably possesses
spaced apart depth calibration markings 22 positioned at intervals
along the length of the shank. Such depth calibration markings
enable the endodontist to determine the depth reached during the
procedure. Such markings are well known in the art and may vary in
size or spacing.
[0032] Referring now to FIG. 2, the shank 10 substantially
traverses the entire length of a root canal having a non-linear
central axis to a point adjacent the distal end of the canal and
the apical foramina 11. The shank 10 should be flexible and possess
shape memory sufficient to return to its original position after
bending. Presently, alloys of nickel and titanium are best suited
for the invention's purposes. In particular, alloys comprising at
least about 30% titanium and at least about 50% nickel are
preferred. Polymer chemistry may soon provide materials suitable
for use as a shank as described by the invention and accordingly
are within the scope of the invention.
[0033] The majority of the shanks utilized in accordance with the
invention will have a uniform diameter from the first end 12 to the
second end 14. Certain applications, however, may require a tapered
shank. Accordingly, the invention encompasses instruments utilizing
a shank that is tapered at an included angle of between about 1/2
and about 5 degrees. In other words, the shank tapers from a
thicker first end 12 to a thinner second end 14.
[0034] The instrument according to the invention further comprises
a coupling for establishing fluid communication between the needle
and a fluid reservoir. Couplings for attaching needles to syringes
are well known to those skilled in the art.
[0035] Most medical syringes may be used with a variety of
interchangeable needles of varying diameter and length, as
envisioned by the apparatus according to the invention. In most
instances, needles are attached to syringes using a Luer coupling
or connector. Luer couplings typically come in two forms, both of
which are attached and detached by application of a simple
mechanical force. One form is a simple conical device which accepts
the needle base. This version is often described as a Luer tip. To
detach the needle, one simply pulls it off by applying a linear
force.
[0036] The other type is often described as a Luer lock. The Luer
lock has a simple screw thread locking mechanism that permits the
base of the needle to be screwed onto the syringe upon the
application of a torque so that it cannot be pulled without
unscrewing. Such connectors are well known to those skilled in the
art and are the subject of numerous patents such as U.S. Pat. No.
6,033,386 to Novacek et al.; U.S. Pat. No. 5,984,373 to Fitoussi et
al.; U.S. Pat. No. 5,047,021 to Utterbery; and U.S. Pat. No.
4,452,473 to Ruschlee.
[0037] Although traditional syringe needle couplings may be
utilized in the practice of the invention, in many instances such
couplings are not practical or even suitable. For example, a
patient's mouth opening is limited and it may be impossible for an
endodontist to reach a tooth, such as a molar, with a needle
attached to a syringe using a traditional linear coupling.
[0038] Currently, endodontists address this problem by bending the
tips of the stainless steel needles used for irrigation. Typically,
a 45.degree.-90.degree. bend is utilized. This functionally
transforms the upper portion of the needle into an extension that
allows the lower portion of the needle to reach a tooth and enter
it through the crown. The flexible nature of the needle utilized in
the practice of the invention makes this option impracticable.
Accordingly, the invention may utilize an extended and angled
coupling that creates a suitable angle between the fluid reservoir
and the needle. An example of such a coupling is shown in FIGS. 2
and 10.
[0039] Referring now to FIG. 10, a connector 40, preferably a Luer
type connector, is shown. Typically, these connectors are formed of
polymers. The connector 40 possesses a first end 42 and a second
end 44 and an intermediate portion 46 positioned between the first
end 42 and the second end 44. The intermediate portion 46 is
elongate and forms an angle, identified generally at A in FIG. 10,
between the first end 42 and the second end 44. The connector also
possesses a lumen (not shown) extending its length providing fluid
communication between the first end 42 and the second end 44.
[0040] The embodiment shown in FIG. 10 is designed such that the
needle is fixably attached at the second end 44 while the first end
42 is removably attached to the distal end of a syringe or fluid
reservoir as shown in FIGS. 2 and 10 and discussed below. In this
design, the distance between the angle A and the first end 42
functions as an extension allowing the endodontist to reach and
enter teeth easily and comfortably both for the endodontist and
patient.
[0041] A further embodiment of the apparatus according to the
invention encompasses an endodontic irrigation syringe of the type
shown in FIG. 10. The syringe 30 according to the invention
comprises a reservoir for retaining irrigation or disinfecting
fluid and means for dispensing a fluid from the reservoir.
Typically, the function of the reservoir and means for dispensing
are provided by a hollow, axially elongated barrel or tube 32 and
plunger 34 combination commonly associated with hypodermic needles
and other such medical devices. The syringe 30 further comprises a
shank 10 of the type previously discussed that is in fluid
communication with the fluid reservoir, fluid communication is
accomplished by means of the connector 40 that is removably
attached to the distal end of the barrel 32. The connector 40 is of
the type previously described.
[0042] A still further embodiment of the invention encompasses a
method for irrigating a root canal possessing a non-linear central
axis. The method comprises inserting an elongate, hollow and
flexible shank or needle of the type previously discussed into a
root canal along a path that generally follows the non-linear
central axis of the root canal. In this manner the distal end of
the needle and its orifices are positioned adjacent the distal end
of the root canal and the apical foramina.
[0043] The insertion of the shank is followed by transferring a
fluid, by way of the needle, from the crown of the tooth along the
non-linear central axis of the root canal to a discharge point
adjacent the apical foramina. Thereafter, the fluid is discharged
from an orifice at the distal end of the needle such that a portion
of the fluid is discharged along a vector that is substantially
perpendicular to the openings of the side canals and tubules
extending from the main root canal and adjacent the apical
foramina. This manner of irrigating and disinfecting provides a
more direct application of fluid to the bottom of the root canal
and the smaller accessory canals that branch from the main canal
thus improving the effectiveness of the overall procedure.
[0044] The invention has been described in detail, with reference
to certain preferred embodiments, in order to enable the reader to
practice the invention without undue experimentation. However, a
person having ordinary skill in the art will readily recognize that
many of the components and parameters may be varied or modified to
a certain extent without departing from the scope and spirit of the
invention. Furthermore, titles, headings, or the like are provided
to enhance the reader's comprehension of this document, and should
not be read as limiting the scope of the present invention.
Accordingly, only the following claims and reasonable extensions
and equivalents define the intellectual property rights to the
invention.
* * * * *