Note: Descriptions are shown in the official language in which they were submitted.
CA 02246~l2 l998-08-l7
WO 97/307~;1 PCT/US97/02802
MET~ODS AND APPARATUS FOR DISPENSING COMPOSITIONS
BACKGROUND OF THE INVENTION
1. The ~ield of the Invention
The present invention relates to methods and ap~a-al~ls for use in dispensing single or
multiple component compositions, such as dental cçment~ or impression materials. More
particularly, the present invention is directed to methods and apparatus for dispensing
10 compositions so that the compositions are substantially free from entrained air.
2. The Relevant Technolo~
To properly place and use dirre.e..L compositions, it is often necess~ry to initially place the
coml)o~ilion in a syringe. In the dental field, for example, it can be very helpful to initially place
15 cem~ntC or binding agents in a syringe. The syringe can then be used to accurately position the
binding agent for proper placement of a dental cap or other dental structure.
The use of a conventional syringe for delivery of a composition, however, can create
pr~bl s. A conventional syringe has a nozzle end and an opposing loading end having a plunger
slidably positioned therein. To fill the syringe with the composition, the plunger is removed and
20 the composition is inserted into the syringe at the loading end. Removal of the plunger, however,
can jeop~ ~ e the sterility of the plunger. This is because the plunger must typically be set down
to enable proper loading of the syringe with the composition.
Once the composition is placed in the syringe, the plunger is inserted back into the loading
end of the syringe. The plunger is then used to push the composition out the nozzle end. As the
25 plunger is reinserted within the syringe, however, air can become trapped between the plunger and
the composition. When low viscosity compositions are used, it is possible to orient the syringe so
that the air within the syringe travels to the nozzle end where the air can be removed prior to
dispersement of the composition. When high viscosity compositions are used, however, the air
remains trapped. As the plunger is advanced, the air becomes entrained, forming air bubbles
30 within the composition .
Depending on the composition and its intended use, the presence of air bubbles can have
a dt;~lime,llal affect. For example, when cements are used in the dental field, such as in bonding
dental caps, air bubbles in the composition can produce an irregularity in the flow of the
composition from the syringe and can also result in an uneven placement of the composition on
35 the desired surface. As a result of the uneven placement, the cap may not be uniformly secured
and thus have a weaker long term bond. The presence of air bubbles can also affect the setting
rate of the composition. That is, the portion of the composition exposed to the air bubbles may
begin setting more ~uickly than the rem~inin~ portion of the composition. This uneven setting
can also influence the resulting effectiveness of the composition.
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SUl~l~RY OF THE ~NVENTION
In accordance with the invention as embodied and broadly described herein, the present
invention provides a novel syringe having an elongated barrel for holding and dispensing a
composition. The barrel has a first or distal end, an open second or proximal end opposite the
first end, and a sidewall extending between the first end and the second ends. The sidewall has
an exterior surface and an interior surface. The interior surface defines a chamber for holding the
composition.
An access port extends through the sidewall of the barrel to communicate with the
chamber. The access port is configured so that the composition can be delivered through the
access port and into the chamber at the distal end of the chamber. By using the access port, the
composition can be positioned within the chamber without having to remove and potentially
co. .~ e the plunger. ~urthermore, since the access port is closer to the first end of the barrel,
use ofthe access port makes it easier to position the composition within the barrel, be~innin~ at
the first or distal end of the barrel and then filling the barrel u~ith composition from the distal end
and working back toward the access port. In the p, ~ ed embodiment, a sufficient amount of
the composition is added so as to fill the ch~nl)er up to the access port. The exact position of the
access port along the lon~it~ in~l dimension of the barrel depends on the unit dose of composition
that is desired to be dispensed from the syringe.
Once the composition is appropriately positioned within the chamber, the plunger can be
advanced towards the first end of the barrel. As the plunger is advanced, the air between the
plunger and the composition is pushed out the chamber through the access port. Once the
plunger passes the access port, the le.~ composition is pushed out a nozzle located at the
first end of the barrel. Having the composition filled to the access port prevents air from being
trapped between the plunger and the access port.
In applications requiring multi-component compositions, the components are placed in
side-by-side orientation within the chamber, rather than one on top of another, to enable optimal
mixing of the components. Once the components are positioned within the chamber, a mixing
paddle is inserted into the chamber through the second or proximal end of the barrel. The paddle
extends to the first or distal end ofthe barrel. Grooves or ducts are forrned on the paddle so that
rotation of the paddle results in efficient mixing of the components within the chamber.
AfLer the multi-component composition is mixed, the paddle is removed from the syringe
barrel and the plunger is then inserted within the second end of the barrel. Optionally, a scraper
member having ~ cent arms that extend into the chamber and engage opposing sides of the
paddle, can be inserted into the access port prior to removal of the paddle. As the paddle is
withdrawn from the barrel, the arms scrape the composition offthe sides of the paddle, retaining
the composition within the barrel. After the paddle member is withdrawn and the scraper is
removed, the plunger is inserted through the proximal or second end of the syringe barrel. ~ere,
again, as the plunger is advanced, the air between the plunger and the composition is pushed out
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ofthe chamber through the access port. Once the plunger passes the access port, the ~ lg
composition is pushed out a nozzle located at the first end of the barrel.
The above described syringe and method of use provides several benefits and
improvements over the prior art. By way of example and not by limitation, since the components
are mixed in the syringe, the composition does not have to be later transferred to the syringe.
Furthermore, rotationally mixing the composition within the chamber n~inil~ es the amount of
air that gets G~ ined within the composition. Furthermore, the side access port provides several
advantages. Most importantly, the access port enables easy delivery ofthe components to the first
or distal end of the syringe and allows air to escape as the plunger is advanced within the chamber.
BRIEF DESCR~PTION OF THE DRAWINGS
In order that the manner in which the above-recited and other advantages and objects of
the invention are obtained will be understood, a more particular description of the invention
l S briefly described above will be rendered by reference to a specific embodiment thereof which is
illustrated in the appended drawings. Underst~nl1ing that these drawings depict only a typical
embodiment ofthe invention and are not lh~::lt;role to be considered to be limiting of its scope, the
invention will be described and explained with additional specificity and detail through the use of
the accompanying drawings in which:
Figure 1 is a perspective view of a syringe assembly having a barrel with an access port
.o.~te~ding through a sidewall thereof;
Figure 2 is an exploded view of the syringe assembly shown in Figure l;
Figure 3 is a perspective view of a filling syringe delivering a composition to the syringe
in Figure I through the access port;
Figure 4 is a perspective view of the syringe in Figure 3 having the composition field to
the access port;
Figure 5 is a perspective view of the syringe in Figure 4 having a plunger advanced to the
composition at the access port;
Figure 6 is a perspective view of a multi-syringe device for use in introducing two
components of a two-part composition into the syringe in Figure l for subsequent mixing therein;
Figure 7 is a perspective view of a paddle used for mixing a two-part composition within
the syringe of Figure l;
~ Figure 8 is a perspective view of the paddle in Figure 7 being inserted within the syringe
for mixing of the components;
3 5 . Figure 9 is a cross-sectional view taken along lines 9-9 of Figure 8 showing in schematic
form by use of arrows how the paddle mixes the composition within the syringe;
Figure 10 is a perspective view of anther presently plerel.~d embodiment ofthe paddle
used to mix a multi-component composition within the syringe of Figure l; and
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Figure 11 is a partially exploded perspective view of a scraper that is selectively inserted
within the access port of the syringe in Figure 1.
DE~TAILED DESCR~PTION OF THE PREFERRED EMBODIMENTS
s
The present invention is directed to methods and appa,~.L~ls for dispensing compositions
such as dental Cçment.~ or imp-~ssion materials. More particularly, the present invention is
directed to methods and apparatus for dispensing compositions such that the compositions are
substantially free from entrained air.
10Figure 1 illustrates a syringe assembly 10 useful for dispensing compositions, such as
dental c.omPn~ and bonding materials in acco~d~ce with the present invention. Syringe assembly
10 includes a hollow, elongated barrel 12 having a nozzle 38 ~tt~ehed at one end and a plunger
48 slidably received in the opposing end. As better shown in Figure 2, barrel 12 includes a first
or distal end 14, and opposing second or proximal end 16 and a substantially cylindrical sidewall
1518 e~tçn~ng therebetween. Sidewall 18 has an exterior surface 20 and an interior surface 22.
Interior surface 22 defines a s~lhst~n~i~lly cylindrical chamber 24 for holding the composition.
In the pl ~re" ed embodiment as shown in Figure 2, a tapered exit tube 26 proiects from
first end 14. Exit tube 26 has an interior surface 28 defining an exit port 30 that longitu-lin~lly
extends through exit tube 26 and communicates with cl,~.lbel 24 at first end 14. Surrounding exit
20tube 26 is an attachment sleeve 32. Attachment sleeve 32 has an interior sur~ace 34 with
engagement threads 36 positioned thereon.
Nozzle 38 is configured to selectively attach in fluid communication with exit tube 26.
To accomplish this end, nozzle 38 has a threaded end 40 for engagement with threads 36 of
~tt~ nt sleeve 32. Opposite threaded end 40 is a flexible and angled spout 42 for guiding
25delivery ofthe composition to a desired location. It is, of course, envisioned that di~e-~-lL sizes
and shapes of spouts 42 can be used depending on the type and intended use of the composition.
Furthermore, in alternative embo~liment~ nozzle 38 could be permanently attached to first end
14 or means other than threads could be used to attach different sizes and/or shapes of nozzles.
Radially extending outward at second end 16 of barrel 12 is an annular flange or handle
3044 that encircles barrel 12. Handle 44 is used in the advancement of plunger 48. As shown in
Figure 2, an opening 46 extends through handle 44 and into chamber 24 at second end 16. The
present invention also provides piston means receivable in chamber 24 at second end 16 of barrel
12 for advancing the composition positioned within barrel 12 through exit port 30 at first end 14.
By way of example, and not by limitation, the piston means comprises an elongated plunger 48
35as depicted in Figures 1 and 2.
Plunger 48 has a lead or distal end 50 and an opposing tail or ~o~ oxil.lal end 54. Positioned
at lead end 50 is a sealing gasket 52. Radially extending outward at tail end 54 is an annular top
56used in advancing plunger 48. Plunger 48 is sized to be slidably received within chamber 24
through opening 46 at second end 16. Plunger 48 also has a length that permits gasket 52 to be
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selectively advanced within the entire length of chamber 24, such that gasket 52 abuts the distal
end 14 of chamber 24 when plunger 48 is fully inserted into chamber 24. Gasket 52 iS made of
a soft, cc,~ lt;ssi~lc, sealing material, such as rubber, which allows the outer periphery of gasket
52 to seal against interior surface 22 of ~halilbel 24 as plunger 48 is advanced within chamber 24.
S In alternative embot1inl~ntc, the piston means can take the form of any size or shape of
conventional plunger used with a conventional syringe.
Referring again to Figure 2, the present invention also provides an access port 58
e~f n~l;ng through sidewall 18 to communicate with chamber 24. In a p~ t;re, l ed embodiment,
access port 58 is subs~lLidlly rect~n~ r having a first edge 60, an opposing second edge 62, and
10 side edges 64. In alternative embo-~im~nts, access port 58 can be any configuration such as
circular, triangular, or square. Access port 58 iS preferably positioned and configured so that the
composition can be de~ivered through access port 58 and into chamber 24 at first end 14.
The exact location of access port 58 relative to the longit~ in~1 axis of chamber 24
depends on the desired unit dose to be administered from the syringe. For example, where the
15 desired unit dose is applox;~ely 3 milliliters, the access port 58 is positioned on the syringe such
that the volume of that portion of ch~l.l)er 24 beginning at the first edge 60 of access port 58 and
eYten~ling to the distal end 14 of chamber 24 is applo~il"a~ely 3 mil1iliters. Thus, a variety of
sylil~es designed for a variety of unit dosages can be produced simply by ch~n~ing the position
of access port 58 relative to the distal end 14 of syringe barrel 12.
As depicted in Figure 3, a filling syringe 66 is used to position the composition within
chamber 24. Filling syringe 66 has a barrel 67 for holding the composition, a plunger 69 for
advancing the composition, and a elongated, rigid, filling tube 68 for directing the composition.
That is, by inserting filling tube 68 through access port 58 so that the end of filling tube 68
extends to first end 14 near exit port 30, the composition contained within filling syringe 66 can
be delivered into chamber 24.
When filling syringe 66 is used, it is pl~lled to have exterior surface 20 ~dj~c~nt to
second edge 62 of access port 58 substantially flat so as to allow a straight and unobstructed
positioning of filling tube 68 within chamber 24. The term "flat" as used in the specification is
defined to mean the absence of any obstructions rising from exterior surface 20. Exterior surface
20 can be cylindrical in shape and still be flat. In a~ternative embodiments, any conventional
means or device can be used to position the composition within chamber 24. Depending on the
device or method used, however, the size and position of access port 58 may have to be varied
to best insure that the composition is positioned at first end 14.
It is preferred to start positioning the composition at first end 14 so as to avoid trapping
~ 35 air bubbles within chamber 24. As the composition is delivered, filling syringe 66 is slowly
removed so, as shown in Figure 4, chamber 24 iS filled with composition 71, beginning at first or
distal end 14 and working back toward access port 58, filling the distal end 14 of chamber 24 to
a point proximate to first edge 60 of access port 58. The positioning of access port 58 is
dependent upon how much composition needs to be delivered from syringe system 10. That is,
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where more composition needs to be delivered, barrel 12 can be formed having access port 58
positioned closer to second end 16. Alternatively, where less composition is needed, access port
58 can be formed closer to first end 14. Once the composition is positioned within barrel 12,
plunger 48, positioned within chamber 24 at second end 16, is advanced towards first end 14. In
so doing, air within chamber 24 at second end 16 is pushed out through access port 58.
It can be ~pl)le,;ated that it is preferred to have the composition filled at least to first edge
60 of access port 58 is to prevent air from being trapped between composition 71 and plunger 48.
It is possible to have the composition filled higher than first edge 60, however, a portion of the
composition may spill out through access port 58 as plunger 48 is advanced. As previously
mentioned, it is also plefe,led to have access port 58 rect~ng~ r so that first edge 60 is
perpendicular to the longitudinal axis of barrel 12. This configuration helps to ensure all ofthe
air is removed as plunger 48 is advanced and provides a clear line as to where the composition
needs to be filled. Once the plunger passes access port 58, as depicted in Figure 5, the
composition is pressed through exit port 30 and through nozzle 38 so as to be delivered through
spout 42.
The present invention also provides methods and apparatus for mixing and dispensing
multi-component compositions such as dental cements or illlples~ioll materials. More particularly,
the present invention also provides syringe mixing and dispensing systems usefill for rapid and
complete mixing of multi-component compositions and subsequent dispensing of the mixed
col,l~o~ilions without the ellLldil)lllent of air and without the nec~c~ity of having to mix the multi-
c~ ollenl composition in one COnkL~ ;il and then having to transfer the mixed composition from
the rnixing container into the syringe.
It is frequently desirable to mix together various components of multi-componentcompositi~nc> such as some dental cements and bonding materials. For purposes of brevity, the
2~ discussion contained herein shall be principally directed to the use of two-component systems,
so"~ c referred to as A and B component systems. Nevertheless, it should be understood that
the methods and apparatus of the present invention will accommodate systems having more than
two components.
The system for mixing and dispensing the multi-components compositions of the present
invention inr.ludes syringe 10 as ~liscllssed previously in Figures I -5. Mixing of the components
is performed by initially positioning the discrete components within first end 14 of chamber 24.
It has been determined that the most effective mixing of the A and B components lltili~ing the
a~pal ~Lus of the present invention is accomplished by loading the two components side-by-side
within syringe barrel 12 rather than one on top of the other. Side-by-side loading may be
advantageously performed by use of a two-syringe device 90, such as that shown in Figure 6.
Two-syringe device 90 includes two syringe barrels 92A and 92B coupled together by clamps
94A, 94B and 94C. Each of syringe barrels 92 A and B has an output end 96A and 96B with a
nozzle 98A and 98B secured thereto. In turn, each nozzle 98A and 98B is provided with an
.lon~t~d tubing member 100A and 100B for directing placement of the individual components.
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A collar 102 is used to secure tubing members 100A and 100B together, with both tubing
members terminating at the same distal end 101.
Prior to use, the syringe barrels 92A and 92B of Figure 6 are filled with A and B
components, respectively, of a two-component composition. First end 14 of syringe barrel 12 is
sealed with a cap, such as the cap 104 illustrated in Figure 8. Tubing members 100A and 100B
are then inserted through access port 58 so that distal end 101 is positioned ~cent to exit port
30 at first end 14. The two plungers 93A and 93B are then ~imlllt~n~ously depressed while slowly
withdrawing tubing members 100A and 100B from within syringe barrel 12. This results in
placement of material from each of syringe barrels 92A and 92B side-by-side within first end 14
of chamber 24. This process is accomplished in substantially the same way as discussed with
Figures 3 and 4 except that now two components are being filled within chamber 24.
It should be understood that additional syringe barrels 92 and associated components
could be added to the device of Figure 6 in order to accommodate more than two components.
Further, the (1i~met~rs of syringe barrels 92A and 92B could be altered as necessary to effect
di~~ g ratios of A and B components. For example, if A and B components are to be added in
subst~nti~lly equal amounts, both syringe barrels 92A and 92B would be substantially identical.
If, however, it were desired to add two parts of A to one part of B, syringe barrel 92A should
have a cross-sectional area twice that of syringe barrel 92B. It will be appreciated that other
modifications could be made in the respective sizes of syringe barrels 92A and 92B to
accommodate other mixing ratios. Markings on the sides of syringe barrels 92A and 92B can be
used to measure a desired volume to be introduced into syringe barrel 12, or one could look at
markings optionally provided on syringe barrel 12.
The present invention also provides blending means selectively inserted within chamber
24 for mixing the components of the composition within first end 14 of barrel 12. As depicted
in Figure 7, one embodiment of the blending means comprises an elongate paddle 106 having a
rotation knob 107 with finger grips 109 positioned at one end. A rotation pin 111 is positioned
at the opposing end of paddle 106. During use, as shown in Figure 8, paddle 106 is inserted
within cll~lll)el~ 24 through opening 46 such that rotation pin 111 is inserted within exit port 30.
Paddle 106 has a length slightly longer than chamber 24 so that rotation knob 107 projects out
of second end 16 when rotation pin 111 is inserted within exit port 30. Once paddle 106 is
properly positioned, rotation of knob 107 causes paddle 106 to rotate within chamber 24, thereby
mixing the components into a homogeneous composition.
The width of paddle member 106 is preferably about the same as the internal ~ met~r of
chall-bel 24. This sizing enab}es more complete mixing by scraping material from interior surface
22 of syringe barrel 12. As illustrated in Figure 7, it is pleselltly pt~r~lled that paddle 106 be
provided with a plurality of internal cutouts 108 and 110 from the body of paddle 106. The
provision of cutouts 10~ and 110 generate turbulence as paddle 106 is rotated. The cutouts
function as means for effecting turbulence within chamber 24 in order to obtain more rapid and
complete mixing. Such mixing can be accomplished with little or no entrainment of air bubbles.
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Figure 9 illustrates in schematic form the generation of turbulence in response to rotation of
paddle. It should be understood that the cutouts 108 and 110 are needed only in the region where
mixing occurs. Thus, the size of paddle 106 and the location of cutouts 108 and 110 depends on
the desired unit dose.
S Alternative embodiments of the elements of the a,opa-~lus of the present invention may
be made as 1Ong as the broad functions set forth above are preserved. One of ordinary skill will
be able to envision many other worlcable alterations in light of the te~hing~ herein. For example,
another presently p~ ed embodiment of the mixing paddle is shown in Figure 10. As
illustrated in Figure 10, paddle 106' has a rotation knob 107', an elongated stem 113', and an
enlarged, s~ y planar mixing portion 115'. Rotation knob 107' has a knurled surface 109'
to facilitate ease of gripping and rotation of knob 107'. Mixing portion 115' has a plurality of
cutouts 108' and 110' that generate turbulence, in a manner similar to that described above in
relation to the paddle illustrated in Figures 7-9, as paddle 106' is rotated . As mentioned
previously. the cutouts function as means for effecting turbulence within chamber 24 in order to
obtain more rapid and complete mixing, which is achieved with little or no e.~L~ ."ent of air
bubbles.
In one embodiment of the present invention, scraper means can be used for removing
material from the surface of paddle 106 after mixing is completed. One embodiment of the
scraper means ;s illustrated in Figure 10. Scraper 120 has an interior surface 122, an exterior
surface 124 and is configured coll-pa,~ble to the size and shape of access port 58. Positioned on
exterior surface 124 is a handle 126. Projecting from interior surface 122 are a pair of adjacent
arms 128 that terminate at distal ends 13Q. Arms 128 are positioned to extend into chamber 24
and snugly fit on opposing sides of paddle 106. Once mixing of the composition is completed,
handle 126 is used to grasp scraper 120 and insert arms 128 through access port 58 and onto
oppo~ing sides of paddle 106. As paddle 106 is removed from chamber 24, arms 128 remove the
composition from offpaddle 106. Arnns 128 are preferably sized so that distal ends 130 of arms
128 are biased against interior surface 122 of chamber 24. This configuration gives greater
support to arms 128 during removal of paddle 106. A~er paddle 106 is removed, scraper 120 can
also removed and plunger 48 inserted.
Once the scraper means is removed and plunger 48 inserted, delivery of the mixedcomposition through nozzle 38 is performed by advancement of plunger 48. This process is
performed in substantially the same manner as previously discussed with Figures 4 and 5.
It will be app,~-,;dted that the present invention may be embodied in other specific forms
without departing from its spirit or es~enti~l characteristics. The described embodiments are to
be C~lL~;~el ed in all . ~pe-;ts only as illustrative and not restrictive, and the scope of the invention
is inflic~tec~ by the appended claims rather than by the foregoing description. All changes which
come within the meaning and range of equivalency of the claims are to be embraced within their
scope.
