WO1998011845A1

WO1998011845A1 - Single use dental dispensing tray

Info

Publication number: WO1998011845A1
Application number: PCT/US1997/007777
Authority: WO
Inventors: Bruce R. Broyles; Anne L. Creo; Sumita B. Mitra; Malcom W. Wilcox
Original assignee: Minnesota Mining And Manufacturing Company
Priority date: 1996-09-23
Filing date: 1997-05-07
Publication date: 1998-03-26
Also published as: AU2831897A

Abstract

A tray (20, 20a, 20b, 20c) for dispensing dental material includes a base (22, 22a), a support (24, 24c) extending upwardly from the base (22, 22a) and a dispensing well (46) depending from an upper wall portion of the support (24, 24c). A rib (30, 30a, 30b) extends along at least part of the periphery of the base (22, 22a) and includes an upper section (32, 32a, 32b) that facilitates containment of any dental material that is inadvertently spilled from the well (46). The rib (30, 30a, 30b) also stiffens the tray (20, 20a, 20b, 20c) and provides a convenient surface for gripping the tray (20, 20a, 20b, 20c), a particular advantage when the dental practitioner is wearing gloves.

Description

SINGLE USE DENTAL DISPENSING TRAY

Background of the Invention

1. Field of the Invention

This invention relates to improvements in trays for dispensing dental materials and is particularly beneficial for low-cost trays adapted to be disposed of after a single use.

2. Description of the Related Art

Many liquid, paste and semi-paste materials used in dental procedures are sold in bulk in a vial, dropper bottle, syringe or other container. In many instances, a small quantity of such material is transferred from the bulk container to a recess or well of a dispensing tray. A brush, swab or other type of applicator is then used to transfer the material from the well to tooth structure of the patient.

Dental dispensing trays are widely recommended for use with only a single patient so that the likelihood of transferring infectious diseases from one patient to another is reduced. Use of dispensing trays also helps to prevent contamination of material remaining in the bulk container. If the dental material is a composition that might be adversely affected by prolonged exposure to atmospheric air or light, the use of a dental dispensing tray helps insure that material remaining in the container stays in optimum condition so long as the cap or other closure of the bulk container is promptly replaced. U.S. Patent No. 5, 377,823, assigned to the assignee of the present invention, describes a dental dispensing tray that is especially beneficial for use with dental materials that cure upon exposure to light. The tray has a substrate with a plurality of wells, and a cover that is slidably attached to the substrate. The cover transmits at least a portion of the visible light spectrum but does not transmit a substantial portion of actinic radiation. The cover enables the user to observe whether or not dental material is present in the well without opening the cover, and yet also prevents sufficient actinic radiation from entering the well when the cover is closed so that dental material in the well does not unduly cure.

Dental dispensing trays of the general type shown in U.S. Patent No. 5,377,823 are cleaned and sterilized after each use so that the tray can then be reused in a procedure for another patient. Such trays are typically made of sturdy, rigid plastic that can suitably withstand handling during multiple uses as well as during repeated cleanings and sterilizations.

In recent years, there has been increased interest in dental dispensing trays suitable for single-patient use. Such trays represent a significant convenience for the dental practitioner, since the time and expense for tray cleaning and sterilization is eliminated. Such trays also further reduce the possibility of transferring contaminated material or infectious disease to a patient.

Conventional dental dispensing trays that are adapted for single- patient use are typically constructed of relatively inexpensive materials. Unfortunately, such construction often results in a relatively flimsy tray that may flex and deform during use. As an example, during a procedure the dental assistant may present the tray to a dentist by grasping the tray on its base. When the dentist dips or wipes an applicator firmly against the bottom of the well, the base of the tray may bend and cause dental material in the well to be spilled.

Moreover, conventional disposable dental dispensing trays are often difficult to handle in use. Many disposable dental trays have a flat, thin base which is difficult to grasp when resting on a larger flat surface. Handling of the trays is a particular problem when the dental practitioner is wearing gloves.

Some dental materials are corrosive or contain chemical sensitizers, and consequently may cause damage or injury when spilled onto a patient, dental practitioner or other person, or when spilled onto a countertop or floor in the dental operatory. Moreover, such dental materials are often relatively expensive. It is also a time-consuming nuisance to replace the material in the well after spillage has occurred.

Summary of the Invention

The present invention is directed in one aspect toward a dispensing tray for dental material that comprises a base extending in a horizontal plane, wherein the base includes a peripheral edge portion. The tray also has a support that extends upwardly from the base, and the support includes an upper wall portion. The tray includes a dispensing well for containing a quantity of dental material, and the well depends from the upper wall portion. A rib extends along at least part of the peripheral edge portion. The rib also extends in an upright direction relative to the base and facilitates gripping of the tray.

Advantageously, the rib increases the rigidity of the tray and in particular strengthens the base of the tray, so that the tray does not unduly deform when handled in normal use. Such construction enables the tray to be made of relatively thin sections of inexpensive plastic. In preferred embodiments of the invention, the rib includes an upper section that functions as a trough or gutter to facilitate containment of any dental material that has inadvertently escaped from the well as might occur, for example, when the tray is unduly tipped while being carried from one location to another.

Another aspect of the present invention relates to a dispensing tray for dental material that comprises a base and a support extending upwardly from the base. The support includes an upper wall portion. The dispensing tray also includes a dispensing well for containing a quantity of dental material, and the dispensing well depends from the upper wall portion. A repositionable adhesive is connected to the base for releasably coupling the tray to a supporting surface. Other aspects of the invention are set out in the drawings as well as the detailed description that follows.

Brief Description of the Drawings

Fig. 1 is a top, front and right side isometric view of a dental dispensing tray constructed in accordance with one embodiment of the present invention;

Fig. 2 is a bottom, front and left side isometric view of the dispensing tray illustrated in Fig. 1 ;

Fig. 3 is an enlarged, front cross-sectional view of the dispensing tray shown in Figs. 1 and 2 and taken along lines 3-3 of Fig. 1 ;

Fig. 4 is a plan view of the dispensing tray shown in Figs. 1-3;

Fig. 5 is a top, front and right side isometric view of one example of a dental dispensing tray previously known in the art;

Fig. 6 is an enlarged cross-sectional view of a portion of a dental dispensing tray constructed in accordance with another embodiment of the present invention;

Fig. 7 is a view somewhat similar to Fig. 6 except in accordance with yet another embodiment of the present invention;

Fig. 8 is a plan view of a dental dispensing tray that is constructed in accordance with still another embodiment of the invention; and

Fig. 9 is a right side elevational view of the dispensing tray shown in Fig. 8.

Detailed Description of the Preferred Embodiments

A tray for dispensing dental material according to one embodiment of the invention is shown in Figs. 1 -4 and is broadly designated by the numeral 20. The tray 20 includes a flat base 22 that extends in a horizontal reference plane when the tray 20 is in normal use, as for example when the tray 20 is placed on a countertop, operatory chair tray or other horizontally extending support surface. The base 22 has a rectangular configuration in plan view and has a peripheral edge portion that extends along its four sides.

A support 24 extends upwardly from the base 22. The support 24 includes four flat sidewalls that extend upwardly in an inclined direction, as well as a flat upper wall portion 26 that extends in a direction parallel to the direction of extension of the base 22. One of the sidewalls of the support 24 is directly connected to one of the peripheral edge portions of the base 22. The support 24 has the general shape of a truncated, four- sided pyramid although other shapes are of course possible. The tray 20 also includes a dispensing well 28 that depends from the upper wall portion 26. Preferably, and as shown, the well 28 has a hemispherical configuration and lacks sharp corners or the like. The well 28 is adapted to contain a quantity of dental material such as adhesives, primers, sealants, luting cements, restoratives and the like. Optionally, the tray 20 may include one or more additional wells located next to the well 28 for containing other dental materials.

The tray 20 also includes an elongated rib 30 that extends along the peripheral edge portion of three sides of the base 22 as well as along a lower, peripheral edge of three sidewalls of the support 24. In plan view, and as can be appreciated by reference to, for example, Fig. 4, the rib 30 extends along a rectangular path and is provided with rounded outer corners. The rib 30 has a generally ^βU^*'-shaped configuration in reference planes perpendicular to its longitudinal dimensions.

As shown in Fig. 3, the rib 30 has an upper section 32 and a lower section 34 that is located beneath the upper section 32. Moreover, the upper section 32 is located outwardly relative to the lower section 34 in directions away from the base 22 and the support 24. The lower section 34 has a bottom surface that is located below the bottom wall of the well 28. The rib 30 also includes an outermost, peripheral flange section 36 that extends outwardly in a direction away from the base 22 and the support 24. In the embodiment shown in the drawings, and as can be observed by referring to Figs. 1 and 3, the flange section 36 extends in a -o- reference plane that is coplanar with the directions of extension of the base 22 although other configurations are also possible. As a consequence, the flange section 36 extends in a horizontal plane when, for example, the tray 20 is placed on a horizontal supporting surface such as an operatory shelf or countertop.

The rib 30 is a particular advantage in that its "U'-shaped configuration helps to contain dental material that has escaped from the well 28. For example, the dental material may escape from the well 28 when the tray 20 is held in the practitioner's hand and inadvertently tipped, or in instances where a brush or other applicator pushes the material up the walls of the well 28 and across the upper wall portion 26. The rib 30 confines the escaped material so that the latter remains on the base 22 or in the rib 30 and does not spill from the tray 20.

The rib 30 also advantageously increases the rigidity of the tray 20 including the support 24 and the base 22. The increased stiffness of the tray 20 helps insure that the tray 20 is not unduly deformed when grasped by the base 22 during the time that an applicator contacts walls of the well 28 to remove dental material. Such increased stiffness also reduces the likelihood that the tray 20 will be deformed to such an extent that materials are spilled from the well 28 when the tray 20 is carried in the practitioner's hand.

Furthermore, the rib 30 provides convenient surfaces for grasping the tray 20 when desired. In particular, the outwardly extending flange section 36, being elevated from the bottom surface of the lower section 34 and consequently spaced from the underlying supporting surface, enables the tray 20 to be readily grasped and lifted from the supporting surface even when the user is wearing gloves.

Preferably, the tray 20 including the base 22, the support 24 and the rib 30 are integrally made of an inexpensive plastic such as high impact polystyrene. The increased stiffness provided by the rib 30 allows the tray 20 to be constructed with relatively thinner cross-sectional dimensions than might be otherwise satisfactory. Such relatively thin sections improve the manufacturer's or user's ability to stack the tray 20 with other trays having similar configurations and also reduce disposal concerns. Preferably, the tray is made using a vacuum forming process. Fig. 5 is an example of a dental dispensing tray 40 of the general type previously known in the art. As shown, the tray 40 includes a support 42 having a configuration somewhat similar to the configuration of the support 24 described above. The tray 40 also includes a base 44 that is integrally connected to the support 42.

The base 44 extends in a horizontal reference plane when the tray 40 is placed on a horizontal supporting surface such as a shelf or countertop. However, the tray 40 is made of relatively thin plastic material and as a consequence the base 44 tends to flex and deform during normal handling. Unfortunately, deformation of the base 44 may distort the shape of the tray 40 to such an extent that dental material contained in a well 46 of the tray 40 is inadvertently spilled. Additionally, the flat, relatively thin base 44 is difficult to grasp when resting on a flat supporting surface, especially when the practitioner is wearing gloves.

Fig. 6 is an enlarged view of a portion of a dental dispensing tray 20a according to another embodiment of the invention. The tray 20a includes a base 22a, a support (not shown) and a well (not shown), all of which are identical to the base 22, the support 24 and the well 28 that are described above.

The tray 20a also includes a rib 30a having an upper section 32a, a lower section 34a and a flange section 36a. The rib 30a including the sections 32a, 34a, 36a is identical to the rib 30 including the sections 32, 34, 36 respectively described above.

However, the tray 20a includes a quantity of adhesive 50a that is directly connected to a curved bottom surface of the lower section 34a. The adhesive 50a advantageously hinders sliding movement of the tray 20a whenever the latter is placed on a surface such as a countertop, shelf or dental instrument tray. For example, when a brush or applicator is used to mix dental material in the well of the tray 20a, such mixing may urge the tray 20a in lateral directions. The adhesive 50a tends to -a- withstand such lateral movement and consequently reduces the likelihood that material will spill from the well. Such an advantage is especially useful for single-use trays that are made of relatively inexpensive and lightweight plastic material. Further, the adhesive 50a enables mixing or dispensing with the tray 20a to be a one-handed operation, since the tray 20a need not be held in use.

Preferably, the adhesive 50a is a repositionable pressure sensitive adhesive. As used herein, "repositionable" refers to the ability to be repeatedly adhered to and removed from a supporting surface without substantial loss of adhesion capability. Most preferably, the device of the present invention may be adhered to and removed from a supporting surface for thirty cycles with no more than 75% loss of peel adhesion. In another aspect, the present invention is removable from a supporting surface when it has been adhered to the surface over a long period of time. Thus, preferably the adhesive 50a used in the present invention does not develop excessive adhesion build-up over time.

Ideally, depending on the supporting surface, the repositionable adhesive 50a must provide sufficient tack (or quick stick) to quickly fix the tray 20a to the desired surface, have sufficiently low peel strength to prevent damage of the surface when the adhesive 50a is removed, and have the appropriate cohesive strength to control the transfer of adhesive 50a to the surface. Cold flow of the adhesive 50a on a surface should be avoided, because this leads to an undesirable building of peel strength over time. Preferably, the adhesive 50a is an acrylate- or methacrylate-based adhesive system comprising infusible, solvent dispersible, solvent insoluble, inherently tacky, elastomeric copolymer microspheres as disclosed in U.S. Pat. No. 3,691 ,140. Alternatively, this adhesive composition may comprise hollow, polymer, acrylate, infusible, inherently tacky, solvent insoluble, solvent dispersible, elastomeric pressure- sensitive adhesive microspheres as disclosed in U.S. Pat. No. 5,045,569.

Preferably, the repositionable adhesive 50a provided on the tray 20a comprises between about 60-100% by weight of hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent- dispersible, elastomeric pressure-sensitive adhesive microspheres having a diameter of at least 1 micrometer, and between about 0-40% by weight of a non-spherical polyacrylate adhesive. These hollow microspheres are made in accordance with the teaching of European Patent Application 371,635. The non-spherical polyacrylate adhesive may be any conventional pressure-sensitive adhesive. Examples of such adhesives are polymers made from the "soft" monomers such as n-butyl acrylate, isooctyl acrylate, or the like, or copolymers made from a soft component, such as isobutylene, n-butyl acrylate, isooctyl acrylate, ethyl hexyl acrylate, or the like; and a polar monomer such as acrylic acid, acrylonitrile, acrylamide, methacrylic acid, methyl methacrylate or the like. Non-spherical polyacrylate adhesives are commercially available, for example, as the Rohm and Haas Rhoplex™ line of adhesives. Preferably, the non-spherical polyacrylate adhesive is present in the repositionable adhesive 50a at an amount of about 10-35% by weight. When the repositionable adhesive 50a additionally comprises a non-spherical polyacrylate adhesive, improved anchorage of the total adhesive to the tray 20a is observed, resulting in less adhesive residue being left on the supporting surface after removal. Also, tacky microsphere-containing repositionable adhesives comprising non-spherical polyacrylate adhesive exhibit excellent shear adhesion properties. These advantageous adhesive properties are obtained without excessive adhesion to surfaces such as painted surfaces that would result in peeling of the paint off of the surface when the tray 20a is removed.

Repositionable adhesives are also known in which microspheres contained in the adhesive are non-tacky. A disclosure of this type of adhesive is provided in U.S. Pat. No. 4,735,837 to Miyasaka.

A repositionable adhesive may be provided by addition of components to conventional adhesive formulations to modify their tack and flow characteristics. U.S. Patent No. 4,599,265 (Esmay) discloses an adhesive having a high degree of cohesive strength that has low tack and maintains peelability from a variety of ordinary surfaces. U.S. Patent No. 4,737,559 (Kellen et al.) describes a PSA formulation in which the viscous flow, and resultant adhesion buildup, is controlled through the addition of a small amount of a free radically polymerizable photocrosslinker.

Another means for providing a repositionable adhesive through the reduction of the adhesive contact area is accomplished by the deposition of a discontinuous or patterned film on a backing. WO 85/04602 (Newing et al.) describes pressure-sensitive adhesive articles comprising a plurality of discontinuous adhesive segments in a pattern on at least a portion of at least one side of a carrier or backing, covering from about ten to about thirty percent of the total surface area of that carrier material. European Patent Application 276,557 (Fry) describes a repositionable pressure-sensitive sheet material comprising a sheet material bearing on one surface a discontinuous non-repetitive adhesive coating covering about 10 to about 85 percent of the surface in the form of individual adhesive islands. U.S. Patent No. 4,889,234 (Sorenson et al.) discloses a discontinuous patterned adhesive label structure in which the level of adhesion is varied according to area of adhesive coverage on the label, the pattern in which the adhesive is coated, and the full coverage adhesive characteristics of the materials used. European Patent Application 279,579 (Tanuma et al.) describes pressure-sensitive adhesive sheets comprising, in one embodiment, a continuous adhesive layer having "irregular sections" (i.e., "...the pressure-sensitive adhesive layer is uneven..."). The uneven adhesive layer, according to the application, is imparted through a variety of pressing, molding, and embossing methods.

Optimal repositionable adhesives 50a used in the tray 20a provide very little adhesive transfer to the supporting surface on which the tray 20a is adhered upon removal of the tray 20a. When the adhesive 50a used contains tacky microspheres, the following test may be performed to determine the amount of microsphere transfer:

An area of sheet material coated with adhesive 50a is marked and observed using an optical microscope. The number of microspheres within the area are counted and this number designated "Y". The marked area of the coated sheet is then adhered to Kromekote™ paper, a commercially available paper for the printing industry, for a few seconds and then removed. The marked area is again observed with an optical microscope, and the number of microspheres remaining in the area are counted and this number designated "Z". Percent microsphere transfer is defined as 100 times the ratio of the difference between the number of microspheres initially present (in the marked area of the coated sheet) after coating and the number of microspheres remaining in the marked area after each adhesion and removal from the paper substrate (Y - Z) to the number of microspheres initially present in the area just after coating.

(Y - Z) Percent transfer = — x 100

Preferably, the repositionable adhesive 50a of the present invention has a microsphere transfer no more than 25%.

When the repositionable adhesive 50a does not contain microspheres, a similar measurement may be performed by determining the weight of adhesive 50a transferred to a substrate from a tray 20a having a known amount of adhesive 50a coated thereon. As above, it is desirable to have no more than about 25% of adhesive 50a transferred to the substrate, regardless of the nature of the adhesive 50a.

Another embodiment of the invention is illustrated in Fig. 7, wherein a tray 20b is identical to the tray 20a described above with the exception that a rib 30b of the tray 20b has a somewhat different configuration than the rib 30a of the tray 20a. In particular, the rib 30b has a flat, horizontally extending lower section 34b and two flat, inclined sections 32b. The sections 32b, 32b, 34b together form a trough having a somewhat trapezoidal shape. A flange section 36b of the rib 30b is similar to the flange section 36a and is connected to the upper end of the outermost upper section 32b. A variety of packaging options may be employed. For example, a number of trays 20a may be applied to a section of boxboard or other relatively stiff sheet material. Optionally, the base 22a may extend past the periphery of the sheet material to facilitate grasping and removing the tray 20a from the sheet material.

The tray 20b also includes a quantity of adhesive 50b that is identical to the adhesive 50a described above. However, the flat lower section 34b enables a larger surface area of the adhesive 50b to contact an underlying supporting surface in comparison to the adhesive located on the curved bottom surface of the lower section 34a mentioned above. Such a larger contact area of adhesive 50b increases the likelihood that the tray 20b will not slide during use.

Another embodiment of the present invention is illustrated in Figs. 8 and 9, wherein a dental dispensing tray 20c has a base 22c, a support 24c, a well and a rib that are identical to the base 22, the support 24, the well 28 and the rib 30 respectively of tray 20. Although not shown, the tray 20c may optionally include a quantity of adhesive such as the adhesive 50a, 50b connected to the rib 30c for hindering sliding movement of the tray 20c when the latter is placed on a flat surface. The tray 20c includes a cover 60c that is releasably connected to an upper wall portion of the support 24c. Preferably, the cover 60c is releasably connected to the upper wall portion by a repositionable adhesive similar or identical to the adhesive 50a described above.

As an example, the cover 60c may be made using a double-sided adhesive tape that comprises a carrier strip 62 c and a quantity of adhesive affixed to both sides of the carrier strip 62c. The side of the carrier strip 62c facing the upper wall portion preferably is covered with a repositionable adhesive for releasably connecting the cover 60c to the support 24c. The opposite, or upwardly facing side of the carrier strip 62c is covered with a high tack pressure sensitive adhesive that connects a plastic panel 64c to the carrier strip 62c. The cover 60c may alternatively be constructed of other materials if desired. Preferably, the panel 64c includes sufficient colorant (preferably, an orange colorant) to prevent transmission of all or at least a substantial portion of actinic radiation, and yet allow passage of at least part of the visible light spectrum. As a consequence, any dental material in the well 28c can be observed even when the cover 60c is in place across the upper wall portion as shown in Figs. 8 and 9. If the dental material is photocurable, the panel 64c prevents sufficient actinic radiation from reaching the material when the cover 60c is closed so that undue curing of the material does not occur. A rear section of the carrier strip 62c extends past a rear edge of the panel 64c and downwardly across a portion of the rear sidewall of the support 24c. The rear section of the carrier strip 62c, and particularly the portion near the rear edge of the panel 64c, provides a hinge area for facilitating opening and closing of the cover 60c. Preferably, the carrier strip 62c is sufficiently rigid to self-support the cover 60c in an open position once the cover 60c is lifted from the upper wall portion of the support 24c.

Preferably, both the carrier strip 62c and the panel 64c extend outwardly in a forward direction from the support 24c to thereby present an overhanging section. The overhanging section functions as a tab to enable the practitioner to readily grasp the cover 60c and open the cover 60c when desired.

The cover 60c is an advantage, in that dental material may be dispensed into the well 28c in a room remote from the dental operatory to further reduce the likelihood of transmission of infectious disease from one patient to another. Before the tray 20c is carried into the dental operatory, the cover 60c is closed in order to prevent spillage of material in the well 28c and also to prevent airborne contaminants from contacting the material in the well 28c. The dispensing trays 20, 20a, 20b, 20c as described above may be used for dispensing a single component or multi-component dental material. Further, the trays 20, 20a, 20b, 20c, and particularly the tray 20c, may be used in dispensing apparatus wherein one of the components is stored in the well and another component is added from a second source by the practitioner to form a predetermined quantity of a multi- component dental material having the first component and the second component in a predetermined weight-to-weight ratio. Those skilled in the art will recognize that a number of variations, additions and modifications may be made to the presently preferred embodiments that are described above without departing from the gist of our invention. For example, the trays 20 - 20c may include two or more wells 28, and may have an overall oval configuration or other configuration in plan view. As a consequence, the scope of the invention should not be deemed limited to the embodiments described above in detail, but instead only by a fair reading of the claims that follow along with their equivalents.

Claims

CLAIMS:

1. A dispensing tray (20, 20a, 20b, 20c) for dental material comprising a base (22, 22a) extending in a horizontal plane, said base (22, 22a) including a peripheral edge portion, a support (24, 24c) extending upwardly from said base (22, 22a), said support (24, 24c) including an upper wall portion (26), a dispensing well (46) for containing a quantity of dental material, said well (46) depending from said upper wall portion (26); characterized in that said tray (20, 20a, 20b, 20c) includes a rib (30, 30a, 30b) extending along at least part of said peripheral edge portion, said rib (30, 30a, 30b) extending in an upright direction relative to said base (22, 22a) and facilitating gripping of said tray (20, 20a, 20b, 20c).

2. The dispensing tray (20, 20a, 20b, 20c) of claim 1 wherein said rib (30, 30a, 30b) extends along at least the major extent of said peripheral edge portion.

3. The dispensing tray (20, 20a, 20b, 20c) of claim 1 wherein said rib (30, 30a, 30b) includes an upper section (32, 32a, 32b) and a lower section (34, 34a, 34b), and wherein said upper section (32, 32a, 32b) is located outwardly relative to said lower section (34, 34a, 34b) in directions away from said support (24, 24c) in order to facilitate containment of dental material that has escaped from said well (46).

4. The dispensing tray (20, 20a, 20b, 20c) of claim 3 wherein said rib (30, 30a, 30b) is elongated and has a generally ^**U"-shaped configuration in longitudinally transverse reference planes.

5. The dispensing tray (20, 20a, 20b, 20c) of claim 4 wherein said rib (30, 30a, 30b) includes an outer flange section (36, 36a, 36b) that extends in a generally horizontally direction. - -

6. The dispensing tray (20, 20a, 20b, 20c) of claim 1 wherein said tray (20, 20a, 20b, 20c) includes a bottom surface, and wherein said tray (20, 20a, 20b, 20c) includes a repositionable adhesive (50a, 50b) connected to said bottom surface.

7. The dispensing tray (20, 20a, 20b, 20c) of claim 6 wherein said rib (30, 30a, 30b) includes said bottom surface.

8. The dispensing tray (20, 20a, 20b, 20c) of claim 1 wherein said tray (20, 20a, 20b, 20c) includes a cover (60c) releasably connected to said upper wall portion for covering said well (46).

9. The dispensing tray (20, 20a, 20b, 20c) of claim 8 wherein said tray (20, 20a, 20b, 20c) includes a repositionable adhesive (50a,

50b) for releasably connecting said cover (60c) to said upper wall portion.

10. The dispensing tray (20, 20a, 20b, 20c) of claim 8 wherein at least a portion of said cover (60c) transmits at least part of the visible light spectrum and is opaque to at least a portion of the actinic radiation.

11. A dispensing tray (20, 20a, 20b, 20c) for dental material comprising: a base (22, 22a), a support (24, 24c) extending upwardly from said base (22, 22a), said support (24, 24c) including an upper wall portion (26), a dispensing well (46) for containing a quantity of dental material, said dispensing well (46) depending from said upper wall portion (26); characterized in that said tray (20, 20a, 20b, 20c) includes a repositionable adhesive (50a, 50b) connected to said base (22, 22a) for releasably coupling said tray (20, 20a, 20b, 20c) to a supporting surface.

12. The dispensing tray (20, 20a, 20b, 20c) of claim 11 wherein said tray (20, 20a, 20b, 20c) includes a rib (30, 30a, 30b) connected to said base (22, 22a), wherein said rib (30, 30a, 30b) includes a bottom surface, and wherein said adhesive (50a, 50b) extends beneath at least a portion of said bottom surface.

13. The dispensing tray (20, 20a, 20b, 20c) of claim 11 wherein said base (22, 22a) has a peripheral edge portion, and wherein said tray (20, 20a, 20b, 20c) includes a rib (30, 30a, 30b) extending along at least a portion of said peripheral edge portion, said rib (30, 30a, 30b) including a bottom surface, and wherein said adhesive (50a, 50b) extends beneath at least a portion of said bottom surface.

14. The dispensing tray (20, 20a, 20b, 20c) of claim 13 wherein said rib (30, 30a, 30b) includes an outer flange section (36, 36a, 36b) that extends in a generally horizontally direction.

15. The dispensing tray (20, 20a, 20b, 20c) of claim 11 wherein said tray (20, 20a, 20b, 20c) includes a cover (60c) releasably connected to said upper wall portion for covering said well (46).

16. The dispensing tray (20, 20a, 20b, 20c) of claim 15 wherein said tray (20, 20a, 20b, 20c) includes a repositionable adhesive (50a, 50b) for releasably connecting said cover (60c) to said upper wall portion.

17. The dispensing tray (20, 20a, 20b, 20c) of claim 16 wherein at least a portion of said cover (60c) transmits at least part of the visible light spectrum and is opaque to at least a portion of the actinic radiation.

AMENDED CLAIMS

[received by the Internationa l Bureau on 03 October 1997 ( 03. 10.97) ; original c la ims 1 -17 replaced by amended claims 1 -17 ( 3 pages ) ]

1. A dispensing tray (20, 20a, 20b, 20c) for dental material comprising a base (22, 22a) extending in a horizontal plane, said base (22, 22a) including a peripheral edge portion, a support (24, 24c) extending upwardly from said base (22, 22a), said support (24, 24c) including an upper wall portion (26), a dispensing well (46) for containing a quantity of dental material, said well (46) depending from said upper wall portion (26); characterized in that said tray (20, 20a, 20b, 20c) includes a rib (30, 30a, 30b) extending along at least the major extent of said peripheral edge portion, said rib (30, 30a, 30b) extending in an upright direction and connected to said base, said rib including an outer flange section that extends in a generally horizontal direction away from said support to facilitate (22, 22a) gripping of said tray (20, 20a, 20b, 20c), said rib being spaced above said base.

2. The dispensing tray (20, 20a, 20b, 20c) of claim 1 wherein said rib (30, 30a, 30b) includes an upper section (32, 32a, 32b) and a lower section (34, 34a, 34b), and wherein said upper section (32, 32a, 32b) is located outwardly relative to said lower section (34, 34a, 34b) in directions away from said support (24, 24c) in order to facilitate containment of dental material that has escaped from said well (46).

3. The dispensing tray (20, 20a, 20b, 20c) of claim 2 wherein said rib (30, 30a, 30b) is elongated and has a generally "U"-shaped configuration in longitudinally transverse reference planes.

4. The dispensing tray (20, 20a, 20b, 20c) of claim 1 wherein said tray (20, 20a, 20b, 20c) includes a bottom surface, and wherein said tray (20, 20a, 20b, 20c) includes a repositionable adhesive (50a, 50b) connected to said bottom surface.

5. The dispensing tray (20, 20a, 20b, 20c) of claim 4 wherein said rib (30, 30a, 30b) includes said bottom surface.

6. The dispensing tray (20, 20a, 20b, 20c) of claim 1 wherein said tray (20, 20a, 20b, 20c) includes a cover (60c) releasably connected to said upper wall portion for covering said well (46).

7. The dispensing tray (20, 20a, 20b, 20c) of claim 6 wherein said tray (20, 20a, 20b, 20c) includes a repositionable adhesive (50a, 50b) for releasably connecting said cover (60c) to said upper wall portion.

8. The dispensing tray (20, 20a, 20b, 20c) of claim 6 wherein at least a portion of said cover (60c) transmits at least part of the visible light spectrum and is opaque to at least a portion of the actinic radiation.

9. A dispensing tray (20, 20a, 20b, 20c) for dental material comprising: a base (22, 22a), a support (24, 24c) extending upwardly from said base (22, 22a), said support (24, 24c) including an upper wall portion (26), a dispensing well (46) for containing a quantity of dental material, said dispensing well (46) depending from said upper wall portion (26); characterized in that said tray (20, 20a, 20b, 20c) includes a repositionable adhesive (50a, 50b) connected to said base (22, 22a) for releasably coupling said tray (20, 20a, 20b, 20c) to a supporting surface.

10. The dispensing tray (20, 20a, 20b, 20c) of claim 9 wherein said tray (20, 20a, 20b, 20c) includes a rib (30, 30a, 30b) connected to said base (22, 22a), wherein said rib (30, 30a, 30b) includes a bottom surface, and wherein said adhesive (50a, 50b) extends beneath at least a portion of said bottom surface.

11. The dispensing tray (20, 20a, 20b, 20c) of claim 9 wherein said base (22, 22a) has a peripheral edge portion, and wherein said tray (20, 20a, 20b, 20c) includes a rib (30, 30a, 30b) extending along at least a portion of said peripheral edge portion, said rib (30, 30a, 30b) including a bottom surface, and wherein said adhesive (50a, 50b) extends beneath at least a portion of said bottom surface.

12. The dispensing tray (20, 20a, 20b, 20c) of claim 11 wherein said rib (30, 30a, 30b) includes an outer flange section (36, 36a, 36b) that extends in a generally horizontally direction.

13. The dispensing tray (20, 20a, 20b, 20c) of claim 9 wherein said tray (20, 20a, 20b, 20c) includes a cover (60c) releasably connected to said upper wall portion for covering said well (46).

14. The dispensing tray (20, 20a, 20b, 20c) of claim 13 wherein said tray (20, 20a, 20b, 20c) includes a repositionable adhesive (50a, 50b) for releasably connecting said cover (60c) to said upper wall portion.

15. The dispensing tray (20, 20a, 20b, 20c) of claim 14 wherein at least a portion of said cover (60c) transmits at least part of the visible light spectrum and is opaque to at least a portion of the actinic radiation.

16. The dispensing tray of claim 11, wherein said bottom surface has a curved, generally "U''-shaped configuration.

17. The dispensing tray of claim 11 , wherein said bottom surface of said rib has a flat configuration.

STATEMENT UNDER ARTICLE 19

Applicant is submitting replacement sheets 15 -17 containing amendments to claim 1 and adding (renumbered) claims 16 and 17. Applicant's amendments to claim 1 is supported by Fig. 3, by original claims 2 and 5 and by page 6, lines 23-27 of the specification. Applicant's new claim 16 is supported by the specification on page 5, lines 22-23, on page 7, lines 24-26 and by Fig. 6. Applicant's new claim 17 is supported by page 1 1, lines 25-27 and by Fig. 7.