Unit dose liquid dispensing and packaging for dental application

An nozzle for storage and application of liquid dental material, such as primer or adhesive, to a preparation site at a patient's teeth, gums or mouth. The nozzle includes a hollow nozzle for containing the liquid dental material. The hollow nozzle can include a flocked, open tip through which the liquid dental material is dispensed. The nozzle also includes a storage block having a plurality of cavities formed therein. A plurality of hollow nozzles can be inserted into the cavities to form substantially air-tight seals between the open tips of the hollow nozzles and the exterior of the cavities. An end of the hollow nozzles opposite from the open tip and exposed above the block includes a breakable seal. Accordingly, the hollow nozzles can be stored in the block for an extended period of time. To apply the liquid dental material to a preparation site, an applicator can be attached to the end of the hollow nozzle exposed above the block. The applicator is adapted to break the breakable seal and force the liquid dental material from the interior of the hollow nozzle through the open tip and onto an application site.

TECHNICAL FIELD
 The present invention relates to a manner of packaging liquid material,
 such as dental liquid, from which the liquid material can be dispensed and
 applied directly to a surface, such as to the surface of a tooth. More
 specifically, the present invention relates to a dispensing tip and tip
 storage device within which liquid material can be stored and from which
 unit doses of liquid material can be dispensed and applied to a surface.
 BACKGROUND
 In performing various dental procedures, dental professionals routinely
 apply various liquid materials to preparation sites on the teeth, gums
 and/or other areas of the mouth of a patient. Such materials include
 primers, adhesives and other liquid dental preparations.
 To the degree possible, storage, preparation and use of these materials
 should be carried out in an environment and manner consistent with good
 infection control practices. Thus, the manner of packaging and storing
 liquid dental materials should accommodate the need to dispense the dental
 material by such a process, including the equipment and devices for
 dispensing, and to maintain an appropriate level of sterility of the
 material over time, especially when multiple doses of material are stored
 in bulk. Typically, this means that the reusable devices and products are
 disinfected with cold sterilants between uses. Certain applying equipment
 or devices are usually sterilized in an autoclave between uses.
 Additionally, in some cases, dental liquids need to be stored in a way to
 limit the permeation of solvents from the dental liquid through its
 container. For example, most dental adhesive systems today contain
 solvents to increase their wettability so that they are easier to apply to
 a tooth surface. During storage, however, it is important to prevent
 substantial evaporation of the solvent from the liquid material in order
 to protect the effectiveness of the liquid material. A vessel made of
 material having a limited permeability to solvents can be used, such as
 made from relatively thick plastic, or a foil pouch can be provided about
 the stored quantity of material. Sealable plastic containers having
 presealable caps or other closures are common from which multiple doses
 can be dispensed. Foil pouches typically contain single doses either
 directly therein, or within a unit dose container sealed therein.
 An advantage of a resealable container having multiple doses is that it
 would typically require less storage space as compared to single dose
 packages. Single dose packages, such as contained within foil pouches,
 require substantially greater space than the volume of liquid dental
 material contained within each package.
 There exist a number of different devices and methods for storing and
 applying such liquid dental materials. One common procedure for storing
 and applying liquid dental materials involves dispensing the dental
 material from a sealable bulk vial into a well which can be either
 reusable or disposable. The sealable vial maintains sufficient sterility
 and avoids excessive evaporation of solvents. Once the liquid material is
 placed into the well, a brush or other fiber tipped applicator is dipped
 into the well so that the fiber tip of the applicator can retain a
 quantity of the liquid material. The material is then coated onto the
 tooth surface or other preparation site. Often, additional coats of the
 material are required and so the applicator will be re-dipped into the
 well so that additional coats can be applied. If the material is light
 cured, such as for example those materials commercially available under
 the trade designation "3M Single Bond Dental Adhesive System" from
 Minnesota Mining & Manufacturing Company of St. Paul, Minn., care must be
 taken to shield the well from light exposure during this procedure. After
 the procedure, the fiber tip of the applicator and the well, if
 disposable, are disposed of. Typically, the entire brush or the brush
 handle; the well, if non-disposable; and the bulk vials are disinfected
 with a liquid disinfectant.
 A number of brush types are known for use as dental applicators and can be
 used with the above procedure. A relatively standard type brush is simply
 a small paint brush comprising bristles fixed with an elongate handle.
 Another type of brush includes relatively small fibers adhered to and
 extending radially from a spherical tip portion of an elongate brush
 handle. Such a brush is known as a flocked tip brush comprising
 nonabsorbent fibers between which liquid can be held in suspension, an
 example of which is commercially available under the trade designation
 "Microbrush" from Microbrush Corporation of Clearwater, Fla. Yet another
 type of brush comprises a reusable brush handle connected with a
 replaceable brush tip. The tip may be a standard bristle type brush or a
 flocked tip. A replaceable flocked tip brush is described in copending
 U.S. design patent application Ser. No. 29/070,517 and in U.S. design Pat.
 No. 377,216 to Mark. This type of brush allows disposal of the brush tip
 and sterilization and re-use of the handle.
 Regardless of the type of brush used with the above described procedure,
 however, the procedure has a number of drawbacks. First, spillage is
 possible either in filling the well from the bulk vial or in applying the
 material to the preparation site. Second, the lid or cap of the bulk vial
 must be handled which can cause contamination, requires two hands and can
 be difficult with gloves on. Third, two hands are also required for both
 filling the well and applying the liquid. Fourth, because the material
 must first be dispensed from a bulk source into the well before
 application, the procedure can be relatively time consuming. Fifth, if the
 well is not disposable, the well must be cleaned and the well, brush,
 applicator handle and bulk vial all must be disinfected. Thus, cleanup can
 also be time consuming. Sixth, if the bulk vial is opaque, it can be
 difficult to determine how many applications of the liquid material are
 left before additional material must be supplied. Finally, gloves make all
 parts of the procedure which require handling or manipulation of items
 difficult. Gloves are typically worn during dental procedures for
 infection control.
 Another system for storage, dispensing, and applying liquid dental material
 delivers the material via a bulk syringe source having multiple doses of
 material. A bulk quantity of liquid dental material is provided in a
 re-usable syringe and dispensed through its hollow dispensing tip. This
 approach allows for direct application of the material to a tooth without
 the need to use a disposable or reusable dispensing well. However, the
 entire syringe must be disinfected after each use. Also, if the bulk
 syringe source is opaque, it can be difficult to determine how many
 applications of the liquid material remain. Care must also be taken to
 effectively reseal the syringe after each use to maintain the material's
 effectiveness.
 A third type of system for applying liquid dental material uses unit dose
 packaging. This type of system uses a disposable package containing
 approximately enough liquid dental material for a single application. An
 example is the delivery system commercially available under the trade
 designation "Optibond Solo" from Kerr Company of Orange, Calif. A small
 plastic container having dental material therein is provided within a foil
 pouch. This process requires opening the sealed foil pouch and
 subsequently breaking a unit dose plastic container to access the liquid
 dental material. Then, a brush or other fiber tipped applicator can be
 used as above to apply the material to a preparation site. This eliminates
 the need for using a well and dispensing the material into the well.
 Because the package is sealed, there is no need for a separate, sealable
 bulk vial for infection control and to prevent excessive evaporation of
 solvents. Also, this system avoids clean-up requirements of a separate
 bulk vial and well. However, the system still requires two hands and
 spillage can occur if the package is set down on a dental tray or in
 transfer of the material from the package to the preparation site with the
 applicator. Additionally, opening the packages can be difficult while
 wearing gloves. Further, as above, storage of the separate unit dose
 packages can take up a relatively large amount of space.
 SUMMARY OF THE INVENTION
 The present invention includes a package for effective and space efficient
 storage, dispensing and application of liquid material which reduces the
 likelihood of spillage during application, can reduce the amount of time
 required for preparation and cleanup, and can allow application of liquid
 material using only a single hand and in a substantially "no-touch"
 process. The package comprises a plurality of dispensing and applying
 nozzles that are provided in a storage block. Although not so limited, the
 present invention is designed to be particularly applicable for storing,
 dispensing and applying dental liquids to a dental preparation site, such
 as a tooth surface.
 In accordance with one aspect of the present invention, a hollow nozzle is
 provided having an open tip through which the liquid material is
 dispensed, and a liquid applicator mechanism at the open tip to retain a
 small quantity of the liquid material for application of the material at a
 preparation site.
 The nozzle preferably contains a unit dose of liquid material so that a new
 nozzle can be used for each application of the material at different
 preparation sites. Moreover, each nozzle is disposable after a dispensing
 and applying process is completed. The liquid application mechanism of
 each tip may comprise any known or developed technique for dispersing
 liquid material about the tip as supplied from a nozzle outlet and for
 holding or suspending a small quantity of liquid material and by which
 liquid can be substantially evenly applied to a surface. Preferably, the
 nozzle tip is flocked to provide small radially extending bristles for
 this purpose. The hollow nozzle is preferably designed for attachment to a
 driver for controlling dispensing of the liquid material from the hollow
 nozzle. In dentistry, the use of a disposable nozzle means that only the
 driver needs to be disinfected after an application. Moreover, no bulk
 vial or well or other equipment is needed to perform the process.
 In accordance with another aspect of the present invention, a packaging
 system includes a plurality of nozzles containing liquid material from
 which the material can be dispensed. The nozzles are stored in a storage
 block that effectively caps each of the nozzles in a convenient, easy
 access way. Each hollow nozzle is removably engaged within a cavity of the
 packaging block to form a seal having a suitable limited solvent
 permeability. This allows liquid dental material, for example, to be
 stored in the hollow nozzle for an extended period of time.
 Preferably, the capping device is a block having a plurality of cavities
 formed therein. A filled nozzle can be inserted into each of the plurality
 of cavities and be stored in the block until used. Moreover, after usage,
 the depleted nozzles can be stored by the storage block until disposal of
 the entire package is desired. More preferably, each cavity forms with
 each nozzle plural seals for limiting solvent evaporation and thus
 increasing shelf life. Also, each nozzle preferably includes a liquid
 application mechanism at its open tip to facilitate application of the
 liquid material, and each cavity is designed to accommodate the liquid
 application mechanism within the cavity. Where the liquid application
 mechanism is a flocked tip or other bristled tip, the cavity is sized at
 its internal end to surround the tip without crushing it. An internal seal
 is preferably created by an intermediate surface portion of each nozzle
 within a cavity, and an outer seal is preferably also provided at the
 surface of the storage block by another surface portion of each nozzle. To
 accomplish the internal and outer seals, each nozzle may be tapered to
 converge toward its tip and the storage block cavities may each be
 comprised of an inner and outer bore portions, with the inner bore portion
 being of a smaller dimension so that the tapered surface of a nozzle can
 contact the cavity at a transition between the outer and inner bore
 portions and at the edge of the outer bore portion with an external
 surface of the storage block. Preferably, the transition comprises an
 annular step surface between cylindrical outer and inner bore portions.
 The nozzle preferably also includes a flange sealing surface to provide
 the outer seal by contacting the external surface of the storage block
 surrounding its respective cavity.

DETAILED DESCRIPTION
 In FIG. 1, a storage, dispensing and applicator nozzle 10 is illustrated
 which is specifically designed for, but not limited to, use in storing,
 dispensing and applying liquid dental material to a dental preparation
 site. A dental preparation site can be any surface of a patient's mouth,
 such as gums or teeth, to which a dental material is to be applied.
 Moreover, the present invention is designed for the dispensing and
 application of liquid dental material to such a preparation site. As
 discussed above in the Background section, in performing various dental
 procedures, dental professionals routinely apply various liquid materials
 to preparation sites on the teeth, gums and/or other areas of the mouth of
 a patient. Such materials include primers, adhesives and other liquid
 dental materials. Where a tooth is to be filled, for example, it is common
 practice to fill the preparation with a dental composite material. The
 composite material is typically held in place by an adhesive, which itself
 may require the application of an etchant directly to the tooth surface to
 improve adhesion. Many manners of applying and curing liquid etchants,
 adhesives and composite materials are known. Nozzle 10, in accordance with
 the present invention, is designed specifically for its benefits in
 storing, dispensing and applying such liquid dental materials directly to
 a tooth surface. It is understood, however, that the nozzle 10 may be used
 for storing, dispensing and applying other liquid materials directly to
 the surface of an object.
 Nozzle 10 can provide for the space efficient storage of liquid dental
 material in accordance with good infection control practice. Nozzle 10 can
 also minimize the likelihood of spillage during application, can reduce
 the amount of time required for preparation and cleanup, and can allow
 application of liquid dental material using only a single hand and in a
 substantially "no-touch" process. For other non-dental applications, the
 same advantages can apply.
 As shown in FIG. 1, nozzle 10 comprises a number of portions of different
 dimension that generally are reduced in size from one end to another.
 Preferably, nozzle 10 is overall generally conical as comprised of plural
 cylindrical portions, including, as shown in FIG. 2, a relatively wide
 upper flange section 12, an intermediate liquid storage section 14, and a
 lower liquid dispensing section 16 which converges to a tip 18. The nozzle
 10 need not be generally conical or comprise cylindrical portions, but
 preferably at least leads to a tip having a size and shape suitable for
 applying liquid to a particular surface. That is, the size and shape may
 differ depending on the particular application. The non-tip end is
 preferably sized and shaped for connection to a driver or other dispense
 causing means (examples of which are described below), which again may
 differ depending on any particular application.
 Preferably, nozzle 10 is formed of plastic or other polymeric material,
 such as polypropylene, for example, so as to facilitate manufacturing,
 such as by injection molding. It is, however, also contemplated to form
 nozzle 10 or portions thereof from other materials with suitable barrier
 properties. The choice of material for the nozzle 10 or any portion
 thereof may depend on the particular application, such as for example
 based upon characteristics of a material such as flexibility,
 deformability, heat resistance, chemical resistance or reactiveness, water
 absorption, burst strength, light transparency (for any given wavelength),
 etc. Furthermore, the internal or external surfaces may be treated, coated
 or otherwise comprise different materials to facilitate the needs of any
 particular application. Examples of suitable materials are disclosed in
 U.S. Pat. No. 5,100,320 to Martin et al., the entire disclosure of which
 is incorporated herein by reference.
 As noted above, nozzle 10 is hollow and, thus, defines an internal cavity
 that preferably extends entirely through the nozzle 10. Specifically,
 flange section 12, storage section 14, dispensing section 16 and tip 18
 each include an internal section 12a, 14a, 16a and 18a, respectively,
 corresponding to respective external sections 12b, 14b, 16b and 18b. As
 shown, the internal sections 12a, 14a and 16a generally also correspond to
 the external shapes of their respective sections 12b, 14b and 16b. This
 also may be varied for a particular application. Sections 12a, 14a and 16a
 may be independently coated or treated.
 Flange section 12 of nozzle 10 has a relatively wide inlet 20 at an upper
 end thereof. A breakable or removable end-seal is preferably provided by a
 seal 19 at inlet 20 for sealing inlet 20 during storage. The seal 19
 preferably comprises a foil/film laminate material that can be heat sealed
 to the perimetric edge defining the inlet 20 as are commonly known for
 providing container end-seals, but may comprise any known or developed
 material. A preferred material is a heat sealable foil/film laminate
 material commercially available from Rexam Company of Mount Holly, N.J.
 under the trade designation D-041-38. Seal 19 may comprise other suitable
 material and may be attached about the perimeter of inlet 20 by heat
 sealing, with adhesive, or by other means so as to provide a substantially
 airtight seal between the interior of nozzle 10 and the exterior thereof
 at inlet 20. Additionally, seal 19 is preferably puncturable to allow
 access to the interior of nozzle 10, as is described in greater detail
 below. Otherwise, a tab or other feature may be added to the seal 19 to
 facilitate easy removal thereof from the inlet 20. It is also contemplated
 that the seal be provided by other mechanisms such as a removable plastic
 cap.
 Flange section 12 is preferably designed for interfitting with a driver
 (described below) and is thus preferably sized and shaped to be quickly
 connectable and disconnectable with such a driver. The nozzle 10 should be
 connectable in a way that permits access to the driver for entering the
 nozzle 10 through inlet 20. A releasable quick connection is preferred
 that will longitudinally fix the nozzle in position to such a driver, but
 permit the nozzle 10 to be disconnected by a radial movement. The enlarged
 size of the flange section 12 relative to the size of the adjacent
 intermediate storage section 14 accommodates this preference.
 Both the interior flange section 12a and exterior flange section 12b
 preferably taper down into the liquid storage section 14. For sealing the
 nozzle 10 in a preferred package construction discussed below, a shoulder
 24 is provided along the surface of the exterior storage section 14b. The
 extent of the shoulder may be minimal to provide an effective sealing
 surface. If sealing by the shoulder 24 is not needed, the shoulder may be
 eliminated or merely provided by any structure as a limiting surface (i.e.
 a structure that doesn't need to surround the nozzle 10 since sealing by
 it is not required). With a cylindrical section 14, as shown, the shoulder
 24 is preferably annular to also create a sealing surface. Another tapered
 portion 15 connects liquid storage section 14 with dispensing section 16.
 The portion 14 (and the taper within section 12 near section 14) may
 alternatively be a stepped portion or may instead provide for a smoother
 transition between the respective sections, which may be defined by
 straight or curved surfaces. The more abrupt transition provided by a
 sharp taper or a step can be beneficial for maintaining a quantity of more
 viscous liquid material 27 above the tip 18 during storage. Section 16,
 including its interior dispensing section 16a and exterior dispensing
 section 16b, preferably gradually converges toward tip 18. Though in the
 embodiment shown, the dispensing section 16 is defined by substantially
 straight surfaces in the longitudinal direction of the nozzle 10, it is
 also contemplated to utilize curved surfaces or to include other wall
 structures or features. For example, a series of stepped surfaces can
 create a similar overall taper of dispensing section 16. A series of
 pleats could be utilized to create a positionable tip 18 that may
 adjustable to allow access to otherwise difficult to reach dental
 preparation sites. As noted above, the choice of material may also be made
 (in addition to or instead of any such feature) to facilitate such a
 function, i.e. to make the tip permanently or elastically deformable.
 Nozzle 10 may be provided open through tip 18 by an outlet 21 or may be
 closed such that an opening must be created prior to dispensing. In the
 case of the latter, the tip 18 may have an extension or portion thereof
 that is to be cut off or removed to make an outlet 21 prior to dispensing.
 In either case, liquid material 27 can be dispensed from interior storage
 section 14a through interior dispensing section 16a for application at a
 preparation site, such as the application of liquid dental material to the
 surface of a tooth. Tip exterior 18b is preferably spherical and also
 preferably includes a liquid application mechanism by which liquid
 material 27 can be applied. The liquid application mechanism has the
 capability to retain or suspend a small quantity of liquid at and at least
 partially about the tip exterior 18b after it has been dispensed through
 the outlet 21 so that the liquid can be applied to a preparation site. The
 liquid application mechanism also advantageously disperses liquid material
 within itself and about at least some of the surface area of the tip 18
 for application of liquid material by a greater portion of the tip 18 than
 just its outlet 21. Where the tip 18 is substantially spherical, such as
 is illustrated, the liquid application mechanism preferably follows at
 least part of, and preferably as much as possible, of the spherical
 surface of tip 18 about the outlet 21. This can maximize the tip surface
 area that is usable to apply liquid material to a preparation sits. The
 liquid application material is fed the liquid material from the outlet 21.
 More than one outlet 21 can be provided connected to a common or discrete
 passages for supply.
 In the embodiment shown in FIGS. 1 and 2, the liquid application mechanism
 comprises a plurality of small, flocked fibers 22 extending substantially
 radially from the spherical tip exterior 18b. The spherical tip exterior
 18b having the flocked fibers 22 is beneficial for applying liquid dental
 material to the surface of a tooth, and in particular for applying such
 liquid material within a cavity prepared in a tooth, i.e. to fit within
 the prepared cavity. This ability may also be modified by the length of
 the flocked fibers 22. A flocked fiber tip can be made by any known or
 developed technique, such as is done in making the flocked tip disposable
 applicators that are commercially available from Microbrush Corporation of
 Clearwater, Fla. under the trade designation "Microbrush." The flocked
 fibers 22 define small interstitial spaces that can advantageously fill
 with liquid material, retain and suspend a small amount of liquid material
 27 after it has been dispensed from outlet 21 to provide for efficient
 application to a preparation site. The fibers 22 also allow relatively
 uniform application of the liquid material over the surface(s) of the
 preparation site, whether irregular, rough, or smooth, and apply liquid
 material 27 in the same way as a brush would. In a tooth cavity, the
 radially extending fibers 22 from a spherical tip exterior 18b permit
 liquid dental material to be applied easily to side and overhang surfaces
 of the tooth cavity as well as the cavity bottom.
 It is also contemplated that the liquid application mechanism be formed in
 other ways and be comprised of other materials. Bristles can be secured at
 the tip 18 in any conventional or developed way, but should be arranged to
 disperse and suspend liquid material in accordance with the present
 invention. The bristles may be conventional in the sense of those that are
 suitable for paint brush type applicators. Another type of liquid
 application mechanism would be a liquid dispersing material, such as an
 open cell foam or woven or nonwoven fabrics such as felt (e.g. as used in
 felt tip markers), covering at least a part of the tip 18. Liquid could
 enter the open cell foam or other material from the outlet 21 and disperse
 therein for application. That is, as with the flocked fibers and brushes
 noted above, such other materials should preferably be able to retain or
 suspend a small quantity of liquid outside of the nozzle tip 18 to
 facilitate application by more than just the tip outlet 21. Resilient
 mechanisms (made up of multiple elements like fibers or bristles or of
 liquid dispersing material like open cell foam) are preferred in that they
 have the added ability to conform and apply liquid material to an
 irregular surface. Moreover, multiple mechanisms can be used together to
 cover various portions of a tip or in combination over one another.
 To effectively dispense some of or the complete quantity of the liquid
 material 27 through outlet 21, nozzle 10 can include a piston 23 as
 illustrated in FIG. 2 that is provided within the interior storage section
 14a. The inner surface defining the interior storage section 14a also
 provides a guide surface for guiding the movement of the piston 23 from
 its initial position to a fully dispensed position. Piston 23 is
 preferably sized and shaped to be movable within the interior storage
 section 14a and to form a substantially liquid-tight seal throughout this
 movement so that substantial leakage of liquid material around the piston
 23 is minimized during dispensing. Although the piston 23 may comprise any
 material usable for this purpose and compatible with the liquid material
 to be dispensed, elastomeric material is preferred. For reasons discussed
 below, piston 23 preferably includes a cone-shaped indentation 25 on the
 rear face thereof, that is, the face of piston 23 not in contact with the
 liquid dental material 27. Pressure applied to the rear face of piston 23
 causes piston 23 to move down along the interior storage section 14a to
 force the liquid material through the dispensing section 16 and ultimately
 to dispense liquid material 27 through outlet 21 to be retained outside
 tip 18 within the liquid application mechanism. In order to make it easy
 for a user to tell when a nozzle 10 has been used, the section 14a could
 be made, coated or otherwise treated to be a different color. Then,
 movement of the piston 23 and evacuation of some of the liquid material
 would reveal a color change of that section.
 As noted above, dispensing nozzle 10 is particularly designed for storage
 of liquid dental material and subsequent dispensing and application
 thereof at a preparation site of a patients teeth, gums or mouth. Nozzle
 10 is preferably sized to allow for storage of an amount of liquid dental
 material required for one typical application to a patient. This may also
 be preferred in many other types of applications.
 As shown in FIG. 2, liquid material 27 is stored in dispensing nozzle 10
 and primarily occupies the interior storage section 14a. Although not
 necessary, an air pocket at tip interior 18a and a portion of interior
 dispensing section 16a is void of liquid material during storage. This
 ability depends largely on the viscosity of the liquid material and the
 manner by which the nozzles 10 are filled with the liquid material 27.
 This manner of filling may be any conventional or developed technique.
 When liquid material 27 is to be dispensed, such as by using drivers as
 described below, piston 23 forces the liquid material 27 from the interior
 storage section 14a, through the interior dispensing section 16a and tip
 interior 18a, and out of the nozzle 10 through the outlet 21. The liquid
 material can then be applied by virtue of the liquid application
 mechanism, such as the flocked fibers 22, onto a tooth surface or other
 preparation site.
 The present invention also relates to a packaging construction for
 effectively capping one or more nozzles 10 for storage of liquid material
 27 as it is contained within the nozzles 10. As is the case with some
 liquid dental materials, preferably the nozzles 10 are to be capped so as
 to limit the evaporation of solvents from the liquid material. FIG. 3 is a
 perspective view of a packaging construction that permits plural nozzles
 10 to be filled and stored as an array and which effectively caps the
 plural nozzles 10 in accordance with the present invention. The packaging
 construction preferably includes a storage block 30 having a plurality of
 cavities 32 formed within the storage block 30 from a top surface 31
 thereof. Each cavity 32 is sized to accommodate a single dispensing nozzle
 10, which is placed into a cavity 32 in a tip-first orientation. Block 10
 is preferably formed of plastic or other similar polymeric material, such
 as polypropylene, but may also be formed of other materials depending on
 any particular application. Moreover, various types of surface treatments
 may be provided to the block material, such as for example metalizing. In
 any case, it is preferable that the block exhibit low permeability to
 solvents and high permeability to oxygen. Preferably, the material and any
 coatings or treatments are chosen so that it, by the portions of the
 storage block 30 described below, will create, with portions of the
 nozzles 10, effective seals. Otherwise, the storage block 30 may be shaped
 and sized to accommodate any number of nozzles 10 and to position the
 nozzles in any desired manner. That is, the nozzles 10 need not be
 arranged in an array, or from a single surface (planar or not) of the
 storage block 30. Where the nozzles 10 have closed tips 18, as
 contemplated above, that must be opened prior to dispensing, the storage
 block 30 could be provided with a cutting mechanism (not shown) for
 cutting tips 18 at a controlled depth to provide outlets 21 through the
 tips 18 prior to use.
 The design and relative dimensions of storage block 30 and nozzles 10 are
 preferably chosen to allow storage block 30 and nozzle 10 to be used both
 for filling a plurality of nozzles 10 with liquid material 27 and for
 storing of the liquid material within the nozzles 10 for an extended
 period of time. As shown in FIG. 4, which is a sectional view of storage
 block 30 taken along section line 4--4 of FIG. 3, each cavity 32
 preferably has a relatively wider outer bore portion 34 which steps down
 to a relatively narrower inner bore portion 36. The transition between the
 outer and inner bore portions may be abrupt or gradual and may be defined
 by any number of straight or curved surfaces as viewed in cross-section.
 Both the outer and inner bore portions 34 and 36 of each cavity 32 are
 preferably generally cylindrical to accommodate the shape of nozzles 10.
 However, if nozzles 10 are differently shaped, then the cavities 32 may
 also be otherwise shaped to allow a tight fit between at least a portion
 of each cavity 32 and a portion of the exterior surface of a nozzle 10
 when a nozzle 10 is positioned in a cavity 32. Moreover, the outer and
 inner bore portions 34 and 36 may be made by any conventional process and
 may not be uniform along their respective lengths.
 The diameter of the outer bore portion 34, particularly at a mouth 38
 thereof, is preferably substantially the same as the outside diameter of
 the exterior storage section 14b of nozzle 10 directly beneath shoulder
 24. Also, the diameter of inner bore portion 36 is preferably such that an
 upper edge thereof will contact the surface of the exterior dispensing
 section 16b somewhere intermediate of the tip 18 and the liquid storage
 section 14. This dimension may actually be slightly smaller if the
 material of the nozzle section 16 is elastically or plastically deformable
 under the applied force. This can enhance the contact to create a better
 seal, as described below. Inner bore portion 36 is also wide enough to
 allow tip 18, including the liquid application mechanism, such as flocked
 fibers 22, to fit inside the inner bore portion 36 without crushing or
 substantially distorting the liquid application mechanism. Further, the
 total depth of the cavities 32 preferably allows tips 18 to be suspended
 above a bottom 40 of each cavity 32 when a nozzle 10 is inserted
 completely therein, i.e. up to its shoulder 24.
 These relative dimensions allow for an overall seal to be created from
 approximately the inlet 20 to the outlet 21 as shown in FIG. 4 for tip 18
 when a dispensing nozzle 10 is placed in a cavity 32 to prevent excessive
 evaporation of solvents from the liquid material 27. To provide this
 overall seal, two individual seals are created according to this
 embodiment between storage block 30 and nozzle 10. First, because the
 outer diameter of exterior storage section 14b just below shoulder 24 is
 preferably substantially the same as the inner diameter of mouth 38 of a
 cavity 32, shoulder 24 extends beyond mouth 38 to form a first seal when
 nozzle 10 is placed in cavity 32. A tight fit along the remainder of the
 exterior storage portion 14b and the surface of the outer bore portion 34
 enhances this first seal. The extension of the shoulder 24 onto the
 surface 31 around the mouth 38 can be minimal depending on the materials
 of the nozzle 10 and the storage block 30. Second, when dispensing section
 16 is positioned within the inner bore portion 36 of cavity 32, a mouth 42
 of inner bore portion 36 will contact and preferably pinch an intermediate
 portion of the exterior dispensing section 16b. This creates a second seal
 for tip 18. The combination of these first and second seals provides an
 overall seal to prevent excessive evaporation of solvents from the liquid
 material 27 between the exterior of a cavity 32 and the inner bore portion
 36 where tip 18 is housed.
 The overall seal provided by each cavity 32 of storage block 30 allows a
 plurality of dispensing nozzles 10 to be filled with liquid material 27 in
 storage block 30. To fill a plurality of nozzles 10 with liquid material
 27, storage block 30 can be populated with dispensing nozzles 10. Nozzles
 10 can then be filled either conventionally or otherwise with liquid
 material 27. Because all the nozzles 10 in a single storage block 30 can
 be handled in one large group instead of individually, the nozzles 10 may
 be filled with multiple dosing heads. That is, dosing heads that will fill
 multiple nozzles at once. Because of the overall seal between outlet 21
 and an exterior of cavity 32, as each dispensing nozzle 10 is being filled
 with dental material 27, a substantial airlock is created in the interior
 region of cavity 32 surrounding each dispensing nozzle 10. This airlock
 will prevent sufficiently viscous liquid dental material 27 from passing
 through each outlet 21 and into each cavity 32. Indeed, as shown in FIGS.
 2 and 4, due to the airlock, liquid material 27 generally does not even
 fill the interior dispensing section 16a of nozzle 10 but mainly fills
 interior storage section 14a thereof. After filling the nozzles 10 as
 positioned by the storage block 30, pistons 23 can be loaded into interior
 storage sections 14a of nozzles 10.
 Seals 19 may then be adhered to inlets 20 of nozzles 10 at flange sections
 12 to provide a seal at each inlet 20. Alternatively, all or some of the
 nozzles 10 may be sealed at their inlets 20 by the same sealing material.
 That is, any number of the inlets 20 can be covered and bonded to a same
 layer of sealing material.
 Shoulder 24 of each nozzle 10 also advantageously positions the flange
 section 12 of each nozzle 10 above the surface 31 of block 30. As a
 result, the flange section 12 can be connected to a driver (as detailed
 below), such as by lateral movement of the driver, without first having to
 lift a nozzle 10 from the block 30. That is, the flange section 12 is
 positioned so that the nozzle 10 can be easily picked directly from the
 block 30.
 It is also contemplated that the nozzles 10 in accordance with the present
 invention may be packaged individually or otherwise in multiple
 quantities. A storage block 30 packaging construction is beneficial for
 all of the reasons set out above. But, if those advantages are not needed
 or desired, any number of caps or sealing techniques can be used for one
 or more of the nozzles 10. For example, a cap having but a single cavity
 with an interior shaped and sized like the interior of cavity 32 described
 above could be used to individually cap a nozzle 10.
 As noted in the Background section, many liquid dental materials contain
 solvents such as ethanol which, if allowed to evaporate, can render the
 liquid dental material less effective and/or un-useable. Thus, a packaging
 construction for such liquid dental material should provide for an
 appropriate shelf life. Without limitation, the following liquid dental
 materials contain solvents which would be expected to benefit from the
 advantages of the nozzle and packaging construction of the present
 invention: the bonding system available under the trade designation "Gluma
 2000" from Bayer A. G. of Germany; the adhesive system available under the
 trade designation "One-Step" from Bisco, Inc. of Schaumburg, Ill.; and the
 "Prime & Bond" Direct Composite Bonding Agent from Dentsply International,
 Inc. of York, Pa.
 To ensure an appropriate shelf life, the overall seal created by the
 packaging construction of the present invention between an outlet 21 of a
 nozzle 10 as positioned within a cavity 32 and the exterior of cavity 32
 acts to prevent substantial evaporation of such solvents. Thus, this
 overall seal allows relatively long term storage of liquid dental material
 as provided within nozzles 10 and as packaged by a storage block 30. To
 evidence this ability, dispensing nozzles substantially the same as nozzle
 10 described above were placed in packaging constructions substantially
 the same as storage block 30. As positioned within a polypropylene storage
 block to create the sealing mechanisms described above, polypropylene
 nozzles were filled with liquid dental material having ethanol as a
 solvent. Specifically, the liquid dental material was the dental adhesive
 available from Minnesota Mining & Manufacturing Company of St. Paul, Minn.
 under the trade designation "3M Single Bond." Twelve nozzles were each
 filled with 0.03 g of such material. The inlets of the nozzles were then
 sealed using a foil material as the seal 19, described above. The nozzles
 were weighed at various intervals over a period of 120 days of storage at
 room temperature. The results of the tests are shown in FIG. 7, which is a
 graph plotting the results comparing the days in storage on the x-axis 60
 versus the percent of liquid weight loss on axis 62.
 As shown, while there was an initial weight loss of about 1% to 2% over the
 first 20 to 40 days, but after about 80 days, the weight loss plateaued at
 between 2.5% and 3%. It is thought that this weight loss was mainly due to
 evaporation of solvent into the airlock, described above, between the
 bottom of the liquid in the dispensing areas of the tested nozzles and the
 exterior of the storage block. A weight loss of 2.5% to 3% is deemed very
 acceptable. Indeed, the samples of dental adhesive were tested for
 adhesion after the 120 days and found to display statistically the same
 adhesion as new material.
 To apply liquid material 27 that is stored in a nozzle 10 to a preparation
 site, such as a tooth, a driver such as the driver 50 shown in FIG. 5 can
 be used. Such driver devices are commercially available from DMG GmbH in
 Germany under the trade designation "Ecu-PEN." The illustrated driver 50
 includes a hollow shaft 52, a plunger 54 having an integral rack portion
 53 and a geared wheel 56. The rack portion 53 of plunger 54 is positioned
 concentrically inside shaft 52 to allow plunger 54 to extend through an
 aperture 58 in one end of driver 50. Geared wheel 56 is fixed in position
 to be rotatable by a wall of shaft 52 and includes a round gear 60 which
 engages the rack portion 53 of plunger 54 so that rotation of the geared
 wheel 56, such as by a users finger, causes plunger 54 to extend or
 retract through aperture 58, depending upon the direction of rotation of
 geared wheel 56. The driver 50 as commercially available is preferably
 modified to have a pointed tip such as shown at 59 in FIG. 5 for
 puncturing the seal 19, if provided, and to drive the piston 23 within the
 nozzle 10 for dispensing.
 To use the driver 50 with a nozzle 10 to dispense liquid material 27, a
 nozzle 10 is attached to the end of driver 50 having aperture 58. To
 facilitate this attachment, driver 50 preferably includes a tip having a
 cutout 62 that permits a nozzle 10 to be loaded onto the driver 50 by
 relative radial movement and which longitudinally fixes the nozzle 10 in
 position with the driver 50. Cutout 62 is provided at one side of the
 driver 50 adjacent to the aperture 58 and is sized to permit the flange
 section 12 and a portion of the section 14 of nozzle 10 to pass radially
 therethrough by lateral relative movement. The aperture 58 is sized for
 positioning the inlet 20 of nozzle 10 in alignment with the plunger 54.
 Further, the cutout 62 is slightly smaller than the respective sizes of
 the relevant nozzle sections so that the nozzle 10 can be snap fit through
 the cutout 62 to attach nozzle 10 to driver 50. The necessary resiliency
 for this snap fit is primarily provided by the nozzle 10 so that it can
 slightly elastically deform as it is loaded in position. Snap-fitting a
 nozzle 10, as positioned by the cooperation of nozzle shoulders 24 and the
 surface 31 of a storage block 30, onto a driver 50 in this way can be
 accomplished with a single hand, without having to touch nozzle 10 or
 first remove it from storage block 30, and with gloves on. It is also
 contemplated to attach a nozzle 10 to driver 50 in other ways such as by a
 threaded connection, a bayonet-type coupling or a coupling similar to a
 Luer fitting or the like.
 Once a nozzle 10 is attached to driver 50, nozzle 10 can be removed from
 storage block 30 to break the overall seal. To cause dispensing of liquid
 material, the geared wheel 56 of driver 50 can be rotated to extend
 plunger 54. As shown in FIG. 5, the pointed tip 59 of plunger 54 is
 extended with the plunger 54 so that when the pointed tip 59 is
 sufficiently extended from driver 50, it will puncture the seal 19 over
 the inlet 20 of nozzle 10. As plunger 54 is extended farther from the
 aperture 58 of the driver 50, it will engage piston 23 at its cone-shaped
 indentation 25 to force piston 23 to move as guided by the interior
 storage section 14a of nozzle 10. As explained above, this will cause
 liquid material 27 that is stored within nozzle 10 to be dispensed from
 outlet 21 of tip 18 and to allow application at a preparation site.
 It is contemplated that a driver, such as driver 50, for applying liquid
 material from nozzle 10 to a preparation site can be any device having a
 plunger, such as plunger 54, which can enter nozzle 10 to cause liquid
 material 27 to be dispensed from outlet 21. A second embodiment of such a
 driver is shown in FIG. 6, which is a side view of a driver 150 as held by
 a user. Driver 150 is a syringe type applicator, such as described in U.S.
 Pat. No. 5,626,473 to Muhlbauer et al., the entire disclosure of which is
 incorporated herein by reference. A hollow shaft 152 contains and guides a
 spring loaded plunger 154. By applying pressure to one end of plunger 154
 against the force of its spring bias, its other end is moved down the
 interior of shaft 152 and into the inlet 20 of nozzle 10. As above, the
 other end of the plunger can be pointed to puncture a seal 19 of a nozzle
 10. The remainder of the dispensing and applying process would be the same
 as described above.
 Use of a nozzle 10 for storing, dispensing and applying liquid material to
 a preparation site has a number of advantages over prior art mechanisms
 for storing and dispensing liquid material as described above in the
 Background section. Moreover the use of a storage block 30 provides its
 own advantages that can be added to that of the inventive nozzle 10. The
 chance of spillage is reduced because the driver 50 can be attached
 directly to nozzle 10 without lifting or otherwise removing nozzle 10 from
 storage block 30. And, once driver 50 is attached to nozzle 10, a user
 must actively move plunger 54 forward into nozzle 10 to cause liquid
 material to dispense. Also, the entire application procedure including
 removing a nozzle 10 from storage, attaching nozzle 10 to a driver,
 unsealing nozzle 10 and applying liquid material to a preparation site can
 take place easily by using one hand even with gloves on. This leaves, for
 example, a dental professional's other hand free, which can be important
 in the performance of dental procedures. Further, because driver 50 can be
 directly attached to nozzle 10 while nozzle 10 is still in storage block
 30, the procedure can be considered "no-touch." This reduces the
 likelihood of contamination or contact of the dental material or the
 nozzle tip 18 with the dental professional's skin or gloves.
 For dental applications, setup time can also be reduced because there is no
 need to pre-measure a given amount of dental material from a bulk vial
 into a well; the amount of liquid in each nozzle 10 in a storage block 30
 is preferably pre-measured to be approximately a unit dose, i.e. the
 correct amount for a single use on a patient. Cleanup can also be
 relatively quick because after use, the nozzles 10 can be either replaced
 back into storage block 30 for disposal or disposed of directly. Also, the
 only item which requires disinfection is the driver 50. Additionally, the
 determination of how many applications of dental material remain before
 material must be re-supplied is relatively simple. It is only necessary to
 count the nozzles remaining in a storage block 30, and/or the number of
 blocks 30 remaining. Because nozzle 10 provides a supply of liquid dental
 material via outlet 21 of tip 18 to the liquid application mechanism,
 there is no need to remove nozzle 10 from a patients mouth to re-apply
 liquid dental material by the liquid application mechanism of the tip 18.
 This can reduce the possibility of drippage from tip 18 and save time in
 applying dental material to a preparation site. Furthermore, because a
 plurality of nozzles 10 can be filled and stored in storage block 30 in
 relatively close proximity, use of the present invention can provide for
 relatively efficient use of space.
 As noted throughout this case, the storing, dispensing and applying device
 of the present invention can be used for all sorts of liquid materials.
 For example, any type of adhesive application would benefit from the
 inventive nozzle design. Moreover, the packaging construction is likewise
 applicable to any such liquids, but in particular where it is desirable to
 facilitate handling (i.e. loading and unloading of nozzles) without
 touching the nozzles and where a sealing arrangement is desired.
 Though the present invention has been described with reference to preferred
 embodiments, those skilled in the art will recognize that changes can be
 made in form and detail without departing from the spirit and scope of the
 invention.