WO1999018007A1

WO1999018007A1 - Packaging for photosensitive materials

Info

Publication number: WO1999018007A1
Application number: PCT/US1998/019019
Authority: WO
Inventors: John C. Subelka; Steven R. Jefferies; Donald A. Kapperman
Original assignee: Dentsply International Inc.
Priority date: 1997-10-07
Filing date: 1998-09-14
Publication date: 1999-04-15
Also published as: AU9314998A

Abstract

A package (10) for a photosensitive material (11) includes an open top (32) container (20) having a base (21) and at least one upstanding wall (22) and having an open area (23) therein. The upstanding wall (22) has a first end (30) proximate to the base (21) and an end (31) proximate to the open top (32). The end (31) proximate to the open top (32) is contiguously formed with a laterally extending web (40). A release layer (50) is removably adhesively affixed to the web (40) and encloses the open area (23). The container (20) and the release layer (50) are substantially non-transmissive of at least a portion of the light spectrum to which the material (11) is photosensitive. In use of material (11), container (20) my be inverted over the material (11) as the material (11) is supported upon a support surface (60).

Description

PACKAGING FOR PHOTOSENSITIVE MATERIALS

Technical Field

The present invention generally relates to packaging. More particularly, the invention relates to packaging for photosensitive materials. Specifically, the invention relates to packaging for photosensitive materials which prevents detrimental or premature exposure of the materials to light during shipping, storage and use of the material. The packaging is non-transmissive of at least the detrimental portion of the light spectrum.

Background Of The Invention

Photosensitive materials are well known in various industries. For example, in the dental arts, photocurable restoratives, fillers and the like are regularly employed. The dentist will prepare or provide the material and then use small portions of it to build up a damaged area of a tooth or to fill a cavity. Subsequent exposure to light, often ultraviolet light, cures or initiates curing of the material.

Because of the photosensitive nature of such materials, premature exposure to light will often have a detrimental effect. To restore a tooth or fill a cavity, the material must remain pliable enough to permit the dentist to work with it as needed. Premature exposure to light may cause the material to begin to cure before it is in the desired location or in the desired shape. This is especially true in areas such as dental operatories which are usually brightly lighted. Because of this problem, many photosensitive dental materials are shipped in a preformed manner. That is, the components to make the final product are shipped separately. The dentist will then mix a number of components, which are often reactive, as needed. These components include for example, monomers, photoinitiators, catalysts, fillers and the like. As the dental practitioner requires an amount of material, it is prepared and then used immediately.

Such uses of the materials avoids some of the problems discussed above, but are time consuming and labor intensive for the dental practitioner. Further, even as the dentist is employing the material at "chairside", the material is still exposed to light and will begin to cure. It is often a judgment, therefore as to how much material to prepare, balancing the expected cure rate with the amount of material required for efficient use of time.

A need exists therefore, for a packaging for photosensitive materials which will prevent the material from being prematurely exposed to the portions of the light spectrum which will induce curing. Further, the material should be provided as a "unit dose" or the approximate amount of material required for a given procedure. The packaging should also be useful during the procedure in limiting the exposure of the material to premature photocuring.

Summary of the Invention

It is therefore, an object of the invention to provide a packaging for materials.

It is another object of the invention to provide a packaging for materials which cure or begin to cure upon exposure to light or at least a portion of the light spectrum.

It is a further object of the invention to provide a packaging for a unit dose of material.

It is still another object of the invention to provide such a packaging which will function to limit the exposure of the material to light even as the material is employed in a procedure.

It is yet another object of the invention to provide a packaging which will facilitate the use of the contained material. These and other objects of the invention, which will become apparent from the description and claims to follow, are accomplished by the invention as now described and claimed.

In general, a package for photosensitive materials, according to the invention, comprises an open top container having a base and at least one upstanding wall and having an open area therein. The at least one upstanding wall has a first end proximate to the base and an end proximate to the open top. The end proximate to the open top is contiguously formed with a laterally extending web. A release layer is removably and adhesively affixed to the web and encloses the open area. The container and the release layer are substantially non-transmissive of at least a portion of the light spectrum to which the materials are photosensitive.

According to a further embodiment of the invention, a packaged photosensitive material comprises in combination: a photosensitive material formed into a unit dose; an open top container having a base and at least one upstanding wall and having an open area therein; said at least one upstanding wall having a first end proximate to said base and an end proximate to said open top; said end proximate to said open top being contiguously formed with a laterally extending web; a release layer removably adhesively fixed to said web and enclosing said open area; said container and said release layer being substantially non-transmissive of at least a portion of the light spectrum to which the materials are photosensitive; wherein said unit dose of material is contained within said open area.

A method according to the invention for working with a unit dose of photosensitive material comprises the steps of: providing the unit dose of material in a package, said package having an open top container having a base and at least one upstanding wall and having an open area therein; said at least one upstanding wall having a first end proximate to said base and an end proximate to said open top; said end proximate to said open top being contiguously formed with a laterally extending web; a release layer removably adhesively fixed to said web and enclosing said open area; said container and said release layer being substantially non-transmissive of at least a portion of the light spectrum to which the materials are photosensitive; removing said release layer from said package; removing the unit dose of material from said package and placing the unit dose of material onto a support surface; repeatedly removing a selected portion of the unit dose of material and inverting and placing said package over the unit dose of material; such that light is prevented from contacting the unit dose of material under said package as said selected portion of the unit dose is employed for its intended purpose.

Brief Description of the Drawings

Fig. 1 is a perspective view of a package for photosensitive materials, according to the concepts of the present invention, and showing a unit dose of material contained therein by phantom lines.

Fig. 2 is a perspective view of an alternative embodiment of the package as shown in Fig. 1.

Fig. 3 is a view as in Fig. 1 , showing the release layer partially removed therefrom, thereby exposing the unit dose of material contained therein.

Fig. 4 is a cross-sectional view taken along line 4-4 of Fig. 3. Fig. 5 is a perspective view of a portion of the package of Fig. 1, shown as being used on a support surface, and showing a dental instrument for environmental purposes.

Fig. 6 is a top plan view of a plurality of packages as in Fig. 1, shown contiguously attached and showing a release layer in phantom lines.

Fig. 7 is a side elevational view of the plurality of packages of Fig. 6, showing the release layer exploded therefrom.

Fig. 8 is a top plan view of an alternative embodiment of the plurality of packages of Fig. 6.

Fig. 9 is a side elevational view of two packages as in Fig. 7, shown as affixed back-to-back and each having a release layer shown in phantom lines and exploded therefrom.

Fig. 10 is a cross-sectional view as in Fig. 4, showing an alternative embodiment of the invention.

Preferred Embodiments for Carrying Out the Invention

A package embodying the concepts of the present invention is generally depicted by the number 10 on the attached drawings. As will be more fully discussed below, package 10 is useful for storing, transporting and using photosensitive materials such as material 11. Any material 11 is within the scope of the invention. While the invention has particular application to photosensitive materials, and more specifically to photocurable dental materials, any material, photosensitive or not is within the scope of the invention. An example of a photosensitive material is TPH™ Spectrum Composite available from Dentsply International Inc., Caulk Division, Milford Delaware.

Package 10 includes an open top container generally indicated by the number 20 having a base 21 and at least one upstanding wall 22 and having an open area 23 therein. (Fig. 4) Package 10 need be of no particular size or shape. It is preferred however, that package 10 be configured to closely hold a unit dose of material 11. One configuration of package 10 is generally rectangular, such that four sidewalls 22 contiguously formed with each other and with base 21 form container 20 (Figures 1, 3-5). Any other shape is within the scope of the invention, including having a singular round sidewall 22 as shown in Fig. 2 as package 10b.

An example of a unit dose of TPH™ Spectrum Composite is about 0.3 grams. With such a unit dose, a package 10 having an open area 23 of about 300 mm² is useful. However, smaller or larger sizes are all within the scope of the invention.

Similarly, material 11 need not be of any particular shape, and may include flat or oblong shapes as shown in Figs. 1 and 4, or more rounded shapes as shown in Fig. 2. The equipment (not shown) used to form the unit dose of material 11 or other criteria, will normally dictate the shape, and a configuration for package 10 may be selected based thereon. Shapes conducive to efficient material handling are envisioned, and all are within the scope of the invention. It is preferred that upstanding sidewall 22 be of sufficient height to allow a user to grasp sidewall 22 to effectively grasp package 10.

Sidewall 22 is preferably an upstanding wall having a first end 30 proximate to base 21 and an end 31 distal to base 21 (Figure 4). Distal end 31 of sidewall 21 is proximate to an open top 32 which opens into open area 23.

Distal end 31 of sidewall 22 is preferably contiguously formed with a laterally extending shelf or web 40. In the characterization of the invention as depicted in Figures 1 and 5, web 40 has four portions 40a-40d. In the invention as shown in Fig. 2, a singular web 40 extends from sidewall 22.

Web 40 serves a number of functions, including providing a convenient surface for a user to grasp. Further, web 40 provides an extended surface for adhesive contact with a release layer to be described below. Web 40 also provides a connector between a plurality of contiguously formed packages 10 as depicted in Fig. 6-9 and as will also be more fully discussed below.

A release layer 50 is removably and preferably adhesively affixed to web 40. Release layer 50 closes open area 23 by being placed in a proximate and opposing relation to open top 32. It is also preferred to configure release layer 50 to be of similar shape and dimension to web 40, although this is not necessarily required. Any releasable adhesive which will not detrimentally affect the unit dose of material 11 is useful.

Although an adhesively releasable release layer 50 is preferred, it is also within the scope of the invention to provide a release layer that is torn, cut or otherwise removed. All are within the scope of the term "release layer".

To facilitate removal of release layer 50 from container 20, a user merely grasps a portion of release layer 50 and peals it from web 40 and distal end 31 of sidewall 22. To help the user in this procedure, a portion of release layer 50 may be left exposed. This may be accomplished by any means, such as by providing a tab 51 (Fig. 2) which does not contact web 40, or by removing (or forming without) a portion 52 of web 40 such that section 50a (Figure 1) of release layer 50 is not in physical contact with web 40 at that location. Any such means or others are within the scope of the invention. As another example, as shown in Fig. 10, web 40 may terminate in a step lip or land 41 which also does not normally contact a proximate portion 50b of release layer 50. This provides an area where a user may grasp release layer 50 to remove it.

Package 10 is preferably substantially non-transmissive of at least a portion of the light spectrum to which the material 11 is photosensitive. It may be substantially non-transmissive of the entire light spectrum by being made of an opaque material, or it may be transmissive of all portions of the spectrum save that to which the material 11 is photosensitive. The latter is useful when it is desirable to be able to see the contents of package 10 for whatever reason.

Similarly^ it is envisioned that a portion of package 10 may be opaque while another portion may be transmissive of all or part of the light spectrum. For example, container 20 may be made opaque while release layer 50 is made partially transmissive, or vice versa.

Container 10 is preferably thermoformed from black or dark pigmented polystyrene or black or dark pigmented plastic material providing a positive light abrrier. Release layer 50 may be formed from a similar material or it may be formed from a flexible material such as a metallized substrate or a paper and foil (preferably aluminium) laminate, having a release coating or permanent sealable coating. With a permanent sealable coating, the package 10 may have to be destroyed, or a portion destroyed, to open. Release layer 50 and container 20 may also be individually formed from laminate materials. For reasons that will be explored below, release layer 50 may be flexible or rigid. Figs. 3 and 4 depict a more flexible release layer 50 partially removed from package 20. A flexible release layer may be formed from a metallized substrate or a paper/foil laminate. A more rigid release layer 50 is depicted in Fig. 1 and may be formed from a more rigid or heavy plastic material.

In use, a unit dose 11 of photosensitive material is provided in package 10. The unit dose of material 11 is protected from premature exposure to light because package 10 is substantially non-transmissive of at least that portion of the light spectrum to which material 11 is photosensitive. When it is desired to use material 11 for its intended purpose, the user will first remove release layer 50. At this point, the user may remove all or a portion of unit dose 11 from package 10. If a portion of material 11 is removed and a portion is left behind, then release layer 50 may be temporarily replaced onto container 20, thereby limiting continued exposure to light. This is further facilitated if release layer 50 is somewhat rigid.

Alternatively, the user may wish to remove all of unit dose of material 11 from package 10. In this instance, the material 11 may be placed on a support surface 60 (Fig. 5). A dental tool 61 used to work with material 11 is depicted in Fig. 5 for environmental purposes. To limit exposure of material 11 to light exposure in this instance, container 20 may be inverted over material 11 such that it covers material 11 as material 11 rests upon support surface 60.

In addition, release layer 50 may be placed upon support surface 60 and then material 11 placed upon the situated release layer 50 (not shown) before package 20 is placed over material 11. This provides an additional and convenient work surface for the user and again, may be facilitated by a relatively rigid release layer 40.

Package 10 may be provided as an individual unit, as shown in Figs. 1 and 2. However, package 10 may also be joined with one or more other packages 10 as shown in Figs. 6-9. Any number of packages 10 so joined, and in any relationship are within the scope of the invention. For example, Fig. 6 depicts five packages 10 contiguously formed by being joined along a portion of web 40. Webs 40 between individual packages 10 may be provided with perforations 70, scored portions (not shown) or the like, to facilitate removal of one or more packages 10 from the others for use. Alternatively, as shown in Fig. 8, there need be no perforations and the joined packages 10 may be cut or torn from the others. No separation is necessarily required in use. Joining of a plurality of packages 10 need be accomplished by no particular means other than those conventional in the art.

Other configurations for joining a plurality of packages 10, such as joining bases 21 (Fig. 9) are also within the scope of the invention. Similarly, a plurality of packages 10 may be joined in rows and columns (not shown), or other configurations without limitation.

It is evident therefore, that the objects of a package for photosensitive materials is carried out by the invention as herein described. All possible aspects of the invention beyond the best mode have not been necessarily described, and the scope of the invention shall only be determined by the following claims.

Claims

We claim:

1. A package for photosensitive materials comprising: an open top container having a base and at least one upstanding wall and having an open area therein; said at least one upstanding wall having a first end proximate to said base and an end proximate to said open top; said end proximate to said open top being contiguously formed with a laterally extending web; a release layer removably adhesively fixed to said web and enclosing said open area; said container and said release layer being substantially non-transmissive of at least a portion of the light spectrum to which the materials are photosensitive.

2. A package as in claim 1 , wherein said container is opaque.

3. A package as in claim 2, wherein said container is fabricated from polystyrene.

4. A package as in claim 2, wherein said release layer is transmissive of a portion of the light spectrum.

5. A package as in claim 4, wherein said release layer is fabricated from a paper and aluminum foil laminate.

6. A packaged photosensitive material comprising in combination: a photosensitive material formed into a unit dose; an open top container having a base and at least one upstanding wall and having an open area therein; said at least one upstanding wall having a first end proximate to said base and an end proximate to said open top; said end proximate to said open top being contiguously formed with a laterally extending web; a release layer removably adhesively fixed to said web and enclosing said open area; said container and said release layer being substantially non-transmissive of at least a portion of the light spectrum to which the materials are photosensitive; wherein said unit dose of material is contained within said open area.

7. A packaged material as in claim 6, wherein said material is a photocurable dental material.

8. A packaged material as in claim 6, wherein said container is fabricated from polystyrene.

9. A method of working with a unit dose of photosensitive material comprising the steps of: providing the unit dose of material in a package, said package having an open top container having a base and at least one upstanding wall and having an open area therein; said at least one upstanding wall having a first end proximate to said base and an end proximate to said open top; said end proximate to said open top being contiguously formed with a laterally extending web; a release layer removably adhesively fixed to said web and enclosing said open area; said container and said release layer being substantially non-transmissive of at least a portion of the light spectrum to which the materials are photosensitive; removing said release layer from said package; removing the unit dose of material from said package and placing the unit dose of material onto a support surface; repeatedly removing a selected portion of the unit dose of material and inverting and placing said package over the unit dose of material; such that light is prevented from contacting the unit dose of material under said package as said selected portion of the unit dose is employed for its intended purpose.

10. A method as in claim 3, wherein said release layer is placed onto said support surface, and the unit dose of material is placed onto said placed release layer prior to said step of inverting and placing said package over the unit dose of material.