Abstract:
Provided packaged orthodontic assemblies and methods compressively retain an orthodontic appliance in a container along opposing sides of the appliance adjacent the bonding surfaces of its base. This can be done using a mechanism that limits contact between the appliance and the container while accommodating a substantial range of transverse base dimensions. This engagement mechanism allows an adhesive-coated appliance to be retained in a consistent orientation for convenient dispensing, while limiting potentially adverse interactions between the adhesive and the container. By avoiding loss of the adhesive components during storage, these assemblies and methods can extend shelf life and provide consistent adhesive handling properties.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application claims priority to application Ser. No. 14/397119, filed Oct. 24, 2014, which claims priority to U.S. 371 Application No. PCT/US2013/036998, filed on Apr. 17, 2013, which claims priority to U.S. Provisional Application No. 61/639332, filed Apr. 27, 2012. All of the aforementioned applications are incorporated by reference herein in their entirety. 
     
    
     FIELD 
       [0002]    Containers and related methods are provided for appliances and assemblies. More particularly, containers and related methods are provided for storing and dispensing appliances and assemblies used in orthodontic treatment. 
       BACKGROUND 
       [0003]    Orthodontics is the specialized field of dentistry concerned with the treatment of crooked teeth. There are many reasons for obtaining orthodontic treatment, including improvements to facial aesthetics and bite function, and easier maintenance of oral hygiene. A predominant form of orthodontic therapy known as “fixed appliance therapy” involves the use of tiny appliances called brackets, which are bonded to the labial or lingual surfaces of a patient&#39;s teeth. Other appliances, called molar tubes, are often affixed to the patient&#39;s molar teeth. Each of these appliances has a precisely defined slot or channel for accommodating a resilient arch-shaped wire (or “archwire”). The brackets, molar tubes, and archwire are collectively known as “braces.” At the beginning of treatment, the archwire is secured to the slot or channel of each appliance during treatment. While the archwire initially adopts a distorted shape, it gradually returns toward its original shape while straightening the teeth associated with it. 
         [0004]    The storage and dispensing of orthodontic brackets, molar tubes, and other appliances before they are bonded to a patient can pose a number of technical challenges. One challenge is inventory management. Most fixed appliances are not universal, and thus differ from tooth to tooth. Additionally, appliances are also differentiated based on the orthodontic prescription and appliance family. For example, brackets with certain slot orientations may be used for some patients but not others, and both ceramic and metal brackets may be used in the same practice. Because orthodontic appliances are tiny, providing a system to manage such an inventory and ensure that the system works efficiently in a busy orthodontic office is not a trivial issue. 
         [0005]    Another issue that can affect the efficiency of an orthodontic practice is the time spent preparing a suitable orthodontic adhesive and applying it to the bonding surface of each appliance. Traditionally these were manual steps, but orthodontic product manufacturers have addressed the problem in different ways. For example, 3M Unitek&#39;s APC II and APC PLUS Adhesive Coated Appliance System precoats the bonding base of each appliance and packages the coated appliance in a sealed labeled container. These containers can then be arranged on a setup tray, where they are opened immediately prior to bonding by the treating professional. 
       SUMMARY 
       [0006]    Adhesive pre-coated orthodontic appliances are generally stored and handled gently because orthodontic adhesives are tacky and can be inadvertently transferred to the packaging materials without proper care. Such a transfer is usually undesirable because it reduces the amount of adhesive on the appliance when it is placed on the tooth. The problem is further complicated when the components of the adhesive are selectively transferred. For example, over time, a resin component of a paste adhesive may leech out of the adhesive and cause a concentration of the adhesive filler component. The result can be an unpredictable change in the adhesive viscosity and handling characteristics. 
         [0007]    While there are various ways to solve this problem, each has notable shortcomings. For example, an adhesive pad may be applied to a bonding base of the appliance and then secured to a porous liner. Such liners, however, tend to absorb a significant degree of resin from the adhesive pad. Alternatively, the adhesive-coated appliance could be suspended in air beneath the tiewings of the bracket to avoid contact between the adhesive and the container. This approach, however, can complicate the technique used to remove the appliance from the container. As yet another option, each appliance could be suspended from a long-axis indicator received in its archwire slot, but this approach introduces a disposable component which must be subsequently removed after bonding, which is wasteful and can be nuisance to the treating professional. Finally, approaches that suspend the bracket often require that different containers be used for different appliance geometries, which can be expensive and impractical for an orthodontic manufacturer. 
         [0008]    The provided packaged orthodontic assemblies and methods overcome the above problems by compressively retaining the appliance in the container along opposing sides of the appliance base adjacent the bonding surfaces of the base. This can be done using a mechanism that limits contact between the appliance and the container while accommodating a substantial range of transverse base dimensions. This engagement mechanism allows an adhesive-coated appliance to be retained in a consistent orientation for convenient dispensing to a treating professional, while also limiting potentially adverse interactions between the adhesive and the container. As a result, this solution can extend shelf life and improve the consistency of adhesive handling properties during storage. This approach can also enable a single package to accommodate appliances having significantly different shapes and sizes, thus avoiding the need to customize a container for each bracket type. 
         [0009]    In one aspect, a packaged orthodontic assembly is provided. The assembly comprises: an orthodontic appliance having a base for attachment to a tooth; and a container having a recess with a bottom surface and a pair of opposing, non-parallel side surfaces providing an enlarged recess entrance, whereby the side surfaces contact opposing sides of the base to retain the appliance in the recess. In another aspect, a packaged orthodontic assembly is provided comprising: an orthodontic appliance having a base for attachment to a tooth, the base having a pair of opposing outer edges; and a container having a recess with a bottom surface and a pair of opposing side surfaces, each side surface including a ledge supporting an outer edge of the base operating to suspend the appliance above the bottom wall of the recess. 
         [0010]    In still another aspect, a packaged orthodontic assembly is provided, comprising: an orthodontic appliance having a base for attachment to a tooth, the base having a pair of opposing outer edges; and a container having a recess with a bottom surface and a pair of opposing side surfaces, each side surface including a ledge contacting a respective outer edge of the base to suspend the appliance above the bottom wall of the recess. 
         [0011]    In yet another aspect, a method of making a packaged orthodontic assembly is provided. The method comprises: providing a container having a recess comprising a bottom surface and a pair of opposing side surfaces having a non-parallel orientation to provide an enlarged recess entrance; placing an orthodontic appliance at least partially within the recess entrance; and urging the appliance toward the bottom surface to compressively retain the appliance along a transverse direction based on contact between the appliance and respective opposing side surfaces. 
         [0012]    In yet another aspect, a method of making a packaged orthodontic assembly is provided, comprising: providing a container having a recess comprising a bottom surface and a pair of opposing side surfaces, each side surface having at least one protrusion for engaging a respective side of the appliance; and urging an orthodontic appliance toward the bottom surface to at least partially deform at least one protrusion, the partial deformation of at least one protrusion enabling the appliance to be compressively retained between the side surfaces. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective view showing an orthodontic assembly according to one embodiment, looking at its facial, mesial, and occlusal sides. 
           [0014]      FIG. 2  is a perspective view of a container component of the orthodontic assembly of  FIG. 1 , looking at its facial, mesial, and occlusal sides. 
           [0015]      FIG. 3  is a facial view of the container of  FIG. 2 , looking at its facial side. 
           [0016]      FIG. 4  is an occlusal cross-sectional view of the container of  FIGS. 2-3  taken along section  4 - 4  of  FIG. 3  and looking at its occlusal side. 
           [0017]      FIG. 5  is a mesial cross-sectional view of the container of  FIGS. 2-4  taken along section  5 - 5  of  FIG. 3  and looking at its mesial side. 
           [0018]      FIG. 6  is a mesial cross-sectional view of the assembly of  FIG. 1 , looking at its mesial side. 
           [0019]      FIG. 6 a    is an inset showing a magnified view the interaction between components of the assembly of  FIG. 6 . 
           [0020]      FIG. 7  is a mesial cross-sectional view of a lidded orthodontic assembly according to another embodiment, looking at its mesial side. 
           [0021]      FIG. 8  is mesial cross-sectional view of the assembly of  FIG. 7 , looking at its mesial side and with the lid partially opened. 
           [0022]      FIG. 9  is a mesial cross-sectional view of the assembly of  FIGS. 7-8 , looking at its mesial side while as an appliance of the assembly is being dispensed. 
           [0023]      FIG. 10  is a mesial cross-sectional view of an assembly according to still another embodiment, looking at its mesial side. 
           [0024]      FIG. 11  is mesial cross-sectional view of an orthodontic assembly according to yet another embodiment, looking at its mesial side. 
           [0025]      FIG. 12  is mesial cross-sectional view of an orthodontic assembly according to yet another embodiment, looking at its mesial side. 
           [0026]      FIG. 13  is mesial cross-sectional view of an orthodontic assembly according to yet another embodiment, looking at its mesial side. 
           [0027]      FIG. 14  is mesial cross-sectional view of an orthodontic assembly according to yet another embodiment, looking at its mesial side. 
           [0028]      FIG. 15  is mesial cross-sectional view of an orthodontic assembly according to yet another embodiment, looking at its mesial side. 
       
    
    
     DEFINITIONS 
       [0029]    As used herein:
   “Mesial” means in a direction toward the center of the patient&#39;s curved dental arch.   “Distal” means in a direction away from the center of the patient&#39;s curved dental arch.   “Occlusal” means in a direction toward the outer tips of the patient&#39;s teeth.   “Gingival” means in a direction toward the patient&#39;s gums or gingiva.   “Facial” means in a direction toward the patient&#39;s lips or cheeks.   “Lingual” means in a direction toward the patient&#39;s tongue.   
 
       DETAILED DESCRIPTION 
       [0036]    Particular embodiments will now be described in further detail by way of illustration and example. Figures are provided for demonstrative purposes and are not necessarily to scale. Like numerals denote like elements where appropriate. 
         [0037]    According to one exemplary embodiment,  FIG. 1  shows a packaged orthodontic assembly designated by the numeral  100 . The orthodontic assembly  100  includes a container  104  with a recess  106 , and an appliance  102  received in the recess  106 . In this case, the appliance  102  is an orthodontic bracket having a base  150 , a body  152  extending outwardly from the base  150 , and an elongated archwire slot  154  extending across a facial surface of the body  152 . The base  150  has a bonding surface adapted for attachment to a tooth surface and an adhesive  156  extending across at least a portion of the bonding surface. The appliance  102  is secured to the rest of the assembly  100  by contact between opposing sides of the base  150  and inner surfaces of the container  104 . 
         [0038]    The container  104  can be made from any of a number of suitable materials known in the art. If the adhesive  156  is light-sensitive, the walls of the container  104  can be made from a suitable light-blocking material, such as a polymeric-metal laminate or metal-filled polymer composite described in U.S. Patent Publication No. 2003/0196914 (Tzou et al.). The container  104  can also be formed using any of a number of known polymer processing methods, such as extrusion, injection molding, or thermoforming. In some embodiments, the polymer composite is based on a resilient thermoplastic such as polypropylene. 
         [0039]    While an orthodontic bracket is shown here, it is to be understood that the container  104  could be adapted for use with other orthodontic appliances having a base for bonding to a tooth surface. Such orthodontic appliances may include, for example, molar or bicuspid tubes, buttons, cleats, and sheaths. 
         [0040]      FIGS. 2-5  further illustrate particular aspects of the container  104 . For improved clarity, the appliance  102  and associated adhesive  156  are not shown in these figures. The container  104  has a substrate  108  and the recess  106  is located in the substrate  108 .  FIGS. 2-3  show a receiving area  107  for the appliance  102  bounded by a first pair of opposing side surfaces  110 ,  112 , a second pair of opposing side surfaces  114 ,  116 , and a bottom surface  118 . The embodiment in  FIGS. 2-5  illustrates that the surfaces  110 ,  112 ,  114 ,  116  which bound the receiving area  107  need not be the outermost surfaces of the recess  106 . In the container  104  as illustrated, the opposing surfaces  114 ,  116  are also the outermost surfaces of the recess, while opposing surfaces  110 ,  112  are not. 
         [0041]    The first pair of opposing surfaces  110 ,  112  are non-parallel, and provide a receiving area  107  with a somewhat enlarged entrance. As shown in  FIG. 5 , the receiving area  107  has a generally trapezoidal shape when viewed from the mesial or distal directions. The second pair of opposing surfaces  114 ,  116  can also be non-parallel, although they are parallel in this embodiment. Alternatively, the first pair of opposing surfaces  110 ,  112  can be parallel and the second pair of opposing surfaces  114 ,  116  can also be parallel. As another option, the bottom surface  118  is generally planar and parallel to areas of the substrate  108  surrounding the recess  106 . Each surface  110 ,  112  has a plurality of discrete rails  120  that are generally parallel to each other and protrude into the receiving area  107 . At least some of the rails  120  on each surface  110 ,  112  are coplanar with reference planes that intersect the appliance  102  when the appliance  102  is seated in the receiving area  107 . 
         [0042]      FIG. 4  is a cross-sectional view that shows in greater detail the arrangement of rails  120  along the side surface  112 . Within the receiving area  107 , eight vertically-aligned rails  120  are evenly spaced along the long dimension of the surface  112 . In the configuration shown, the gaps between adjacent rails  120  are approximately four times the width of the rails  120  themselves. Optionally and as shown, a matching set of rails  120  are present on the opposite facing surface  110 . If desired, the shape of each rail  120 , overall width of each rail  120 , and pitch (or spacing) of the rails  120  may be adjusted according to the rail material and type of engagement required by the application at hand. In one preferred embodiment, the rails have an average width of about 0.25 millimeters (0.010 inches) and an average height of about 0.38 millimeters (0.015 inches). 
         [0043]      FIG. 5  is another cross-sectional view rotated 90 degrees from that shown in  FIG. 4 . The cross-section is taken along a reference plane passing through a pair of opposing rails  120  located on respective surfaces  110 ,  112 . This figure also shows the taper in the rails  120 , reflecting the taper in the associated surfaces  110 ,  112  more generally. The taper can be characterized by an angle θ between a normal to the bottom surface  118  and a leading edge  122  of the rail  120 , as shown. Although the leading edge  122  is parallel to adjacent portions of the side surface  112  in this embodiment, this need not be the case. For example, the leading edge  122  may have one degree of taper while adjacent portions of the side surface  112  may have another. 
         [0044]    As an alternative, the degree of taper can be defined by the obtuse angle α formed between the bottom surface  118  and the leading edge  122 , where α=θ+90 degrees in the container configuration shown. As still another alternative, the degree of taper could also be defined based on the orientation of one side surface  110  relative to the opposing side surface  112 . In  FIG. 5 , this angle β formed between these surfaces would be 2θ, although this condition would not necessarily hold true where the side surfaces  110 ,  112  are not symmetrically disposed. 
         [0045]    In some embodiments, the angle θ is at least 5, at least 10, or at least 15 degrees. In some embodiments, θ is at most 45, at least 35, or at least 25 degrees. The angle α can be at least 95 degrees, at least 100 degrees, or at least 105 degrees, and can be at most 135 degrees, at most 125 degrees, or at most 115 degrees. Finally, in exemplary embodiments, β is at least 10, at least 20, or at least 30 and is at most 90 degrees, at most 70 degrees, or at most 50 degrees. 
         [0046]      FIGS. 6 and 6   a  show, in more detail, the mechanical interaction between the rails  120  and the appliance  102  when the appliance  102  (in this case coated with an adhesive  156 ) is placed into the recess  106  and urged toward the bottom surface  118  of the receiving area  107 . As mentioned previously, the appliance  102  is secured within the recess  106  of the container  104  by contact between the occlusal-gingival surfaces  110 ,  112  of the receiving area  107  and the occlusal and gingival sides of the appliance  102 . Advantageously, the rails  120  engage opposing sides of the base  150  to compressively retain the appliance  102  in a suspended configuration that avoids contact between the adhesive  156  and the bottom surface  118 . In a preferred embodiment, there is an interference fit between the appliance  102  and the plurality of rails  120 . 
         [0047]    Optionally and as shown, one or more of the rails  120  are at least partially collapsible. In the inset  FIG. 6 a   , the rails  120  are sufficiently soft that the leading edge  122  of each rail  120  compressively deforms upon the urging of the appliance  102  into the receiving area  107  of the recess  106 . This deformation, which may be elastic, plastic, or a combination of both, can result in the rails  120  closely conforming with the base  150  of the appliance  102 , resulting in a more secure engagement. This is especially useful where there is significant variation amongst the geometries of different appliances. Such variation may be due to differences in base sizes for different brackets, minor defects, or even manufacturing tolerances. By using collapsible protrusions, such as rails  120 , it can be possible to afford a configuration for the container  104  that can accommodate a wide variety of appliances  120  in the recess  106 . 
         [0048]    Alternative configurations are possible. In some embodiments, for example, the container  104  compressively retains the appliance  102  along a transverse direction other than the occlusal-gingival direction. For example, the opposing surfaces  114 ,  116 , which face in the generally mesial and distal directions, could engage respective mesial and distal sides of the appliance  102 . As a further alternative, the four surfaces  110 ,  112 ,  114 ,  116  could simultaneously engage all four sides of the appliance  102  when the appliance  102  is seated in the container  104 . Occlusal-gingival engagement is generally preferred, however, because orthodontic appliances tend to show less variation in occlusal-gingival height compared with mesial-distal width. Additionally, maintaining an open space adjacent the mesial and distal sides of the appliance  102  provides locations where a treating professional can access the appliance  102  with tweezers or some other hand instrument. 
         [0049]    As a result of the mechanical engagement between the appliance  102  and the rails  120 , the appliance  102  is suspended in a fixed position above the bottom surface  118 . In this position, the appliance  102  and its associated adhesive are vertically spaced apart from the bottom surface  118 , thus avoiding substantial contact between the adhesive and the container  104 . Other features of the container  104  can also affect the extent of contact. For example, as shown in  FIGS. 3-4 , the leading edge  122  of each rail  120  has a somewhat pointed, blade-like geometry. This aspect can further limit the contact between the appliance  102  and the container  104  when the appliance  102  is seated in the recess  106 . As an alternative to the rails  120  illustrated here, it is also possible to use prongs, bumps, or other protrusions on one or both side surfaces  110 ,  112  to achieve the same or a similar function. 
         [0050]    Certain unexpected advantages derive from limited contact between the appliance  102  and the container  104 . First, reducing interfacial contact has the effect of deceasing surface area along which adhesive components can wick away from the base  150  of the appliance  102 . This is especially beneficial when dealing with heterogeneous adhesives, for example adhesives that have an unhardened dental composition absorbed into a compressible material, as described in U.S. Patent Publication No. 2009/0233252 (Cinader). Loss of certain components, for example initiators such as camphorquinone, can have detrimental effects on adhesive shelf life and cause aspects of adhesive texture, such as viscosity, to change during long storage periods. Second, decreased interfacial contact generally results in the base  150  applying greater compressive stress to the side surfaces  110 ,  112  when the appliance  102  is seated into the receiving area  107 . Since this compressive stress is reciprocated in a state of equilibrium by the walls defining the surfaces  110 ,  112 , the walls of the container  104  can more readily deform against the appliance  102 , resulting in a more secure grip on the appliance  102 . 
         [0051]    The tapered side surfaces  110 ,  112  in  FIGS. 2-6  provide additional advantages. First, the presence of a taper in the surfaces  110 ,  112  can even further reduce the interfacial area between the base  150  and the leading edge  122  of the rails  120  by limiting contact to the corner of the base  150  adjacent the bonding surface, as shown in  FIG. 6 a   . This reduces the opportunity for loss of the adhesive or adhesive components. Second, a slight taper provides a mechanical advantage that enables deformation of the collapsible rails  120  when the appliance  102  is pressed into the receiving area  107 . This, in turn, can provide a more conformal and secure retention of the appliance  102  as described earlier. Third, the taper allows the receiving area  107  to be “universal,” accommodating appliances having a wide variety of sizes and shapes. The result is a reduction in manufacturing costs, since the same container geometry can be used to package orthodontic appliances having different occlusal-gingival heights, for different teeth, and even between different appliance families. 
         [0052]    The totality of the above features can help minimize adhesive loss when the appliance  102  is plucked from the container  104  during an orthodontic bonding procedure. In some embodiments, the adhesive loss is at most 2 percent, at most 5 percent, or at most 20 percent of the original coating weight of the adhesive  156  on the base  150  of the appliance  102 . In a preferred embodiment, essentially all of the adhesive  156  is maintained on the base  150  when the appliance  102  is dispensed from the container  104 . 
         [0053]    An optional feature of the assembly  100  is shown in  FIGS. 7-9 . First, referring to  FIG. 7 , the assembly  100  has a removable lid  130  (or cover) that extends over the opening of the recess  106  to isolate the appliance  102  from the external environment. The lid  130  has a top surface  132  and a bottom surface  134 , and may or may not be hermetically sealed along the interface between the bottom surface  134  and the areas of substrate  108  surrounding the recess  106 . The lid  130  extends beyond the substrate  108  on one side, resulting in a tab  138 . Suitable lidding materials may include light-blocking materials such as, for example, laminates with a thermoplastic layer, a metallic layer, and a heat seal coating, as described in U.S. Patent Publication No. 2003/0196914 (Tzou et al.). 
         [0054]    Also illustrated in  FIG. 7 , a compressible member  136  is secured to the bottom surface  134  of the lid  130 , the member  136  residing in the recess  106  when the lid  130  is in its closed position. The member  136  contacts the facial surface of the appliance  102  (opposite the base  150 ) and provides an additional safeguard to prevent the appliance  102  from moving (or “skating”) significantly in directions perpendicular to the bottom surface  118  or alternatively “tipping over” within the receiving area  107 . Advantageously, the member  136  can prevent the appliance  102  from becoming dislodged from the receiving area  107  when the assembly  100  is subjected to shock and vibration. Optionally and as shown, the member  136  contacts one or more surfaces of the appliance  102  at a non-zero angle relative to the bottom surface  118  of the receiving area  107  to help prevent the appliance  102  from sliding laterally in the receiving area  107 . 
         [0055]    The member  136  decreases in volume and conform to facial surfaces of the appliance  102  in response to compressive forces that result from closing the lid  130  over the recess  106 . Depending on its stiffness, the member  136  could also assist in securing the appliance  102  by applying a continuous, positive force to urge the appliance  102  toward the bottom surface  118  of the receiving area  107 . Although not shown, the side of the member  136  that engages the appliance  102  can optionally have a generally concave shape when relaxed. Such a configuration could be complementary with at least a portion of the facial side of the appliance  102  and avoid excessive compression of the member  136  when the lid  130  is closed. 
         [0056]    Various compressible materials can be used to construct the member  136 , including soft porous, polymeric open-celled and closed-cell foams, woven and non-woven materials. Preferred foam materials include ethylene propylene diene monomer and crosslinked polyethylene. In an exemplary embodiment, the member  136  has a compression deflection at 25 percent at a pressure of at most 14 kilopascals (2 pounds per square inch). Further options and advantages associated with packaged assemblies including compressible members are described in provisional U.S. Patent Application Ser. No. 61/350,623 (Cinader, et al.). 
         [0057]      FIG. 8  shows the opening of the lid  130  by pulling on the tab  138  in an upward, peeling motion resulting in the bottom surface  134  becoming separated from the underlying surfaces of the substrate  108 . As shown, the member  136  pulls away from the appliance  102 , causing the member  136  to spring back toward its original, relaxed shape. In some embodiments, the lid  130  is completely removed from the substrate  108  as depicted in  FIG. 9 , providing open access to the recess  106  and the appliance  102  during a bonding procedure. As further illustrated in  FIG. 9 , a treating professional can then grip and remove the appliance  102  from the container  104  using, for example, a suitable hand instrument  140 . 
         [0058]      FIG. 10  show an alternative assembly  200 , in which an appliance  202  having a body  252  and a base  250  coated with an adhesive  256  is secured in a recess  206  of a container  204 . The container  204  has generally opposing side surfaces  210 ,  212  that are tapered relative to each other. The container  204  differs from those of previous embodiments in that the surfaces  210 ,  212  do not include rails or any other protrusions to limit the contact between the appliance  202  and the container  204 . Instead, the taper in the surfaces  210 ,  212  assists in limiting contact of these components with each other to a narrow corner region extending along opposing sides of the base  250 . As described in previous embodiments, the walls in the container  204  defining the surfaces  210 ,  212  apply compressive force to the base  250  to retain the appliance  202  in the recess  206 . 
         [0059]      FIG. 11  shows a packaged assembly  300  according to still another embodiment. The assembly  300  includes a container  304  with a recess  306 , and an appliance  302  received in the recess  306 . As before, the appliance  302  has a base  350 , a body  352  extending outwardly from the base  350 , and an adhesive  356  extending across a bonding surface of the base  350 . It is to be understood that only a partial view is shown and other aspects of the assembly  300  are similar to those previously described for assemblies  100 ,  200 . 
         [0060]    The assembly  300  differs from the assemblies  100 ,  200  in that the container  304  does not engage the appliance  302  along tapered side surfaces. Instead, the container  304  has a pair of ledges  324  upon which the appliance  302  rests. Optionally and as shown, the ledges  324  are generally parallel to, and spaced apart from, a bottom surface  318  of the recess  306 . The ledges  324  contact portions of the adhesive  356  extending along the outer edge of the base  350  to suspend the appliance  302  and its associated adhesive  356  above the bottom surface  318 . The recess  306  further includes a first pair of side surfaces  310   a,    312   a  extending along the ledges  324  and contacting opposing sides of the base  350  to prevent lateral movement of the appliance  302  within the recess  306 . A second pair of side surfaces  310   b,    312   b  extends below the ledge, but does not come into contact with the base  350 . 
         [0061]    While  FIG. 11  shows the appliance  302  supported by virtue of the adhesive  356  contacting the ledges  324 , it is also possible for the ledges  324  to support the appliance base  350  without any interposing structure. For example, where the adhesive coats only a center portion of the bonding surface of the base  350  or is absent entirely, the outer edges of the base  350  of the appliance  302  can rest directly against the ledges  324 . This type of configuration can be beneficial, for instance, where essentially zero contact between the adhesive  356  and the container  304  is desired. 
         [0062]    In a preferred embodiment, the ledges  324  are as narrow as possible to avoid substantial contact between the adhesive  350  and the container  304 , thereby reducing the surface area along which adhesive components could be lost during storage and/or transport. In some cases, however, it may be desirable for the ledges  324  to be made broader, particularly if a plurality of appliances having disparate base sizes are to be accommodated in the same container configuration. As another possibility, some or all of the ledges  324  or side surfaces  310   a,    310   b  may also be tapered as previously described to reduce the contact area between the appliance  302  and the container  304 . 
         [0063]      FIG. 12  shows an assembly  400  combining beneficial characteristics of both assemblies  200  and  300 . The appliance  402  has a body  452  extending from a bonding base  450 , and an adhesive  456  extends along at least a portion of the bonding surface of the base  450 . Once again, the appliance  402  is received in the recess  406  of a container  404  having opposing surfaces  410 ,  412 . In this embodiment, however, the surfaces  410 ,  412  have a “stair-step” configuration with alternating horizontal and vertical edges provided at a fine scale. As a result, the surfaces  410 ,  412  are functionally tapered on a macroscopic scale, while parallel on a microscopic scale. Like other tapered configurations, the use of a stair-step pattern can enable the container  404  to accommodate a range of base sizes, but provides the added benefit of creating a “positive stop” against the horizontal edges of the surfaces  410 ,  412  when seating the appliance  402  in the recess  406 . Having a positive stop, in turn, helps avoid over-compressing the appliance  402  in the container  404 , which could lead to difficulties in removal. The stair-steps may also be radiused to reduce the likelihood of the appliance  402  inadvertently slipping past one of the surfaces  410 ,  412  and disengaging from the container  404 . A further variant is provided in  FIG. 13 , which shows an assembly  500  with an appliance  502  and container  504 . The appliance  502  resides in a recess  506  of the container  504  and is essentially identical to appliances previously described. The container  504  includes upper and lower openings  570   a,    570   b  extending along the perimeter of the recess  506 . Each opening  570   a,    570   b  has an inner diameter “A” (or inner transverse dimension “A”) that is slightly smaller than the outer diameter “B” (or outer transverse dimension “B”) of a base  550  of the appliance  502 . Because the base  550  is oversized compared with the inner diameter of the openings  570   a,    570   b,  the openings  570   a,    570   b  abut the upper and lower edges of the base  550 , thereby retaining the appliance  502  in a fixed vertical position within the recess  506 . In preferred embodiments, the openings  570   a,    570   b  are sufficiently thin that a treating professional can easily engage or disengage the appliance  502  from the openings  570   a,    570   b  by gently urging the appliance downward or upward with a suitable hand instrument. 
         [0064]    Still another variant is shown in assembly  600  of  FIG. 14 , in which an appliance  602  contacts the top edge of at least one wire strand  680  that functions as a spacer between a base  650  of the appliance  602  and the bottom surface of a recess  606  located in a container  604 . In this embodiment, an adhesive  656  extends across the base  650  of the appliance  602  and rests upon the strand  680  to suspend the appliance  602  within the recess  606 . As shown here, opposing sides of the base  650  also contact the side surfaces of the recess  606 , although this need not be the case. 
         [0065]      FIG. 15  shows yet another assembly  700  that includes an appliance  702  having a bonding base  750  and retained in a recess  706  of a container  704 . In this embodiment, opposing walls of the recess  706  include a plurality of upper and lower bumps  760   a,    760   b  that collectively engage the outer edges of the base  750  to suspend the appliance  702  above the bottom surface of the recess  706 . To initially seat the appliance  702  in the container  704 , the appliance  702  can be urged into the recess  706 , causing opposing walls of the recess  706  to be deflected away from each other and allowing the base  750  to lodge between the upper and lower bumps  760   a,    760   b.  The reverse action can be used to remove the appliance  702  from the recess  706 . The force required to engage and disengage the appliance  702  can be adjusted based on the size or shape of the bumps  760   a,    760   b  and the stiffness of the recess walls. 
       Embodiments 
       [0000]    
       
         1. A packaged orthodontic assembly comprising: an orthodontic appliance having a base for attachment to a tooth; and a container having a recess with a bottom surface and a pair of opposing, non-parallel side surfaces providing an enlarged recess entrance, whereby the side surfaces contact opposing sides of the base to retain the appliance in the recess. 
         2. The assembly of embodiment 1, wherein each side surface forms an obtuse angle relative to the bottom wall ranging from 95 to 135 degrees. 
         3. The assembly of embodiment 2, wherein the obtuse angle ranges from 100 to 125 degrees. 
         4. The assembly of embodiment 3, wherein the obtuse angle ranges from 105 to 115 degrees. 
         5. The assembly of embodiment 1, wherein each side surface has at least one protrusion for engaging a respective side of the appliance, the at least one protrusion being at least partially collapsed. 
         6. The assembly of embodiment 5, wherein the at least one protrusion comprises at least one rail that, when relaxed, is generally coplanar with a reference plane intersecting the appliance. 
         7. The assembly of embodiment 1, wherein the side surfaces have a stair-step configuration. 
         8. A packaged orthodontic assembly comprising: an orthodontic appliance having a base for attachment to a tooth; and a container having a recess with a bottom surface and a pair of opposing side surfaces, each side surface having at least one collapsible protrusion contacting a respective side of the appliance to retain the appliance in the recess, each protrusion being generally coplanar with a respective reference plane intersecting the appliance. 
         9. A packaged orthodontic assembly comprising: an orthodontic appliance having a base for attachment to a tooth, the base having a pair of opposing outer edges; and a container having a recess with a bottom surface and a pair of opposing side surfaces, each side surface including a ledge supporting an outer edge of the base operating to suspend the appliance above the bottom wall of the recess. 
         10. The assembly of embodiment 1 or 8, further comprising an adhesive extending across at least a portion of the base. 
         11. The assembly of embodiment 10, wherein the adhesive comprises a compressible material. 
         12. The assembly of embodiment 11, wherein the adhesive further comprises an unhardened dental composition absorbed into the compressible material. 
         13. The assembly of embodiment 1, 8, or 9, wherein the container is made from a resilient polymer. 
         14. The assembly of embodiment 1, 8, or 9, wherein the appliance is retained in the recess by an interference fit. 
         15. The assembly of embodiment 1, 8, or 9, wherein the side surfaces contact the occlusal and gingival sides of the base. 
         16. The assembly of embodiment 15, wherein the side surfaces of the container contact the base at a location where the occlusal-gingival dimension of the base is largest. 
         17. The assembly of embodiment 1, 8, or 9, further comprising a lid extending across at least a portion of the recess. 
         18. The assembly of embodiment 17, wherein the lid comprises a compressible member contacting a side of the appliance opposite that of the base to restrain movement of the appliance in directions perpendicular to the bottom surface. 
         19. A method of making a packaged orthodontic assembly comprising: 
       
     
         [0085]    providing a container having a recess comprising a bottom surface and a pair of opposing side surfaces having a non-parallel orientation to provide an enlarged recess entrance; 
         [0086]    placing an orthodontic appliance at least partially within the recess entrance; and 
         [0087]    urging the appliance toward the bottom surface to compressively retain the appliance along a transverse direction based on contact between the appliance and respective opposing side surfaces.
   20. The method of embodiment 19, wherein each side surface comprises at least one collapsible protrusion that engages a side of the appliance.   21. A method of making a packaged orthodontic assembly comprising: providing a container having a recess comprising a bottom surface and a pair of opposing side surfaces, each side surface having at least one protrusion for engaging a respective side of an orthodontic appliance; and urging an orthodontic appliance toward the bottom surface to at least partially deform at least one protrusion, the partial deformation of at least one protrusion enabling the appliance to be compressively retained between the side surfaces.   22. The method of embodiment 19 or 21, wherein the appliance has a base for attachment to a tooth and the assembly further comprises an adhesive extending across at least a portion of the base, the at least one protrusion reducing contact between the adhesive and the container whereby substantially all of the adhesive is maintained on the base when the appliance is dispensed from the container.   23. A method of making a packaged orthodontic assembly comprising: providing a container having a recess comprising a bottom surface and a pair of opposing side surfaces, each side surface having a ledge generally parallel to the bottom surface and spaced apart from the bottom surface; and placing an orthodontic appliance in the recess wherein either a base of the appliance, or an adhesive disposed thereon, flatly engages the ledges to suspend the appliance above the bottom surface, wherein the side surfaces contact opposing sides of the base to prevent lateral movement of the appliance within the recess.   
 
       EXAMPLES 
       [0092]    Objects and advantages of this invention are further illustrated by the following examples. While particular materials and amounts thereof are provided herein, these should not be construed to unduly limit this invention. Unless otherwise noted, all parts and percentages are on a weight basis and all molecular weights are weight average molecular weight. Also unless otherwise noted, all solvents and reagents were obtained from Aldrich Chemical Company in Milwaukee, Wis. 
       Appliance Preparation 
       [0093]    Adhesive-coated appliances were based on CLARITY brand SL brackets (3M Unitek, Monrovia, Calif.). Four different bracket types were tested, including lower anterior, lower bicuspid, upper central, and upper cuspid brackets. After procurement, the bonding surface of each bracket was coated with an adhesive that incorporates a compressible material, as generally described by Example 1 of pending U.S. Patent Application Ser. No. 61/428,498 (Cinader et al.), filed on Dec. 30, 2010. 
       Container Preparation 
       [0094]    The containers in this test were manufactured by injection molding a polypropylene homopolymer resin (ExxonMobil Chemical, Houston, Tex.) compounded with a silver colorant. The lidding is a laminate foil, with a sealing layer of polypropylene. After the appliance was placed in the recess of the container, the lidding was placed over the recess and sealed against the container using a standard heat sealing machine. 
         [0095]    In some of the Examples, a separate foam piece was attached to the lidding such that the foam applied slight positive pressure urging the appliance toward the bottom surface of the container when the lidding was closed. The foam attached to the lid is made of soft crosslinked polyethylene (Sekisui Alveo AG, Lucerne, Switzerland). The shape is oval, to match the blister shape, it is undersized to the dimensions of the blister itself The foam is adhered to the lid via heat sealing machine (the polypropylene layer on the lid is melted to the polyethylene foam) with appropriate fixturing to align the foam. This is done in a process prior to heat sealing the lid to the blister. 
       Resin Loss Measurement 
       [0096]    The resin loss calculations were obtained using the following procedure.
       1) Three gravimetric measurements were taken to obtain the data:
           a) First, the bare bracket was weighed, and then coated with the adhesive.   b) Second, the bracket and adhesive were weighed together and stored in a container for an extended period of time.   c) Third, the bracket and adhesive removed from the container and weighed again.   
           2) The difference between measurement b) and measurement c) above was defined as the “adhesive loss.”   3) Steps 1 and 2 above were repeated as needed to provide measurements on at least 8 replicated packaged appliances (i.e., n≧8).       
 
       Examples 1-8 and Comparatives CE-1 and CE-2 
       [0103]    The average levels of adhesive loss obtained for four different bracket types were determined using the Resin Loss Measurement procedure above and presented in Table 1. As shown in the Table, Examples 1-8 include packaged lower anterior brackets, lower bicuspid brackets, upper central brackets, and upper cuspid brackets, where each bracket was stored in a container having either a foam lidding or plain lidding. Each package then underwent ship testing per ASTM D-4149. All of Examples 1-8 were stored in the container for at least 1 week and in some cases, up to 3 weeks. In some cases, as noted, adhesive resin was observed on the bottom surface of the container after removal of the bracket. 
         [0104]    Comparatives CE-1 and CE-2 represent upper central and lower anterior brackets, respectively, that were coated with adhesive and then placed flatly upon the horizontal bottom surface of a plain, unlined container (such as described in Example 1 of U.S. Patent Publication No. 2003/0196914 (Tzou, et al.)) for approximately 24 hours at ambient temperatures. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Measured resin loss upon removing orthodontic appliances from their container 
               
             
          
           
               
                   
                   
                 Bracket type/ 
                 Coating 
                 Adhesive 
                 Adhesive 
                   
               
               
                 Example 
                 n 
                 lidding 
                 weight (mg) 
                 loss (mg) 
                 loss (%) 
                 Notes 
               
               
                   
               
             
          
           
               
                 1 
                 18 
                 Lower anteriors/ 
                 3.08 
                 0.15 
                 5.3% 
                 Resin remaining  
               
               
                   
                   
                 foam lidding 
                   
                   
                   
                 on bottom 
               
               
                   
                   
                   
                   
                   
                   
                 (3 samples) 
               
               
                 2 
                 16 
                 Lower anteriors/ 
                 3.09 
                 0.16 
                 5.5% 
                 Resin remaining  
               
               
                   
                   
                 plain lidding 
                   
                   
                   
                 on bottom 
               
               
                   
                   
                   
                   
                   
                   
                 (4 samples) 
               
               
                 3 
                 18 
                 Lower bicuspids/ 
                 4.58 
                 0.11 
                 2.4% 
                 Resin remaining  
               
               
                   
                   
                 foam lidding 
                   
                   
                   
                 on bottom 
               
               
                   
                   
                   
                   
                   
                   
                 (7 samples) 
               
               
                 4 
                 8 
                 Lower bicuspids/ 
                 4.60 
                 0.07 
                 1.6% 
                 Resin remaining  
               
               
                   
                   
                 plain lidding 
                   
                   
                   
                 on bottom 
               
               
                   
                   
                   
                   
                   
                   
                 (1 sample) 
               
               
                 5 
                 14 
                 Upper central/ 
                 4.80 
                 0.12 
                 2.7% 
                 Resin remaining  
               
               
                   
                   
                 foam lidding 
                   
                   
                   
                 on bottom 
               
               
                   
                   
                   
                   
                   
                   
                 (1 sample) 
               
               
                 6 
                 13 
                 Upper central/ 
                 4.81 
                 0.06 
                 1.3% 
                 Resin remaining  
               
               
                   
                   
                 plain lidding 
                   
                   
                   
                 on bottom 
               
               
                   
                   
                   
                   
                   
                   
                 (1 sample) 
               
               
                 7 
                 20 
                 Upper cuspids 
                 4.61 
                 0.05 
                 1.2% 
                   
               
               
                 8 
                  8 
                 Upper cuspids 
                 4.63 
                 0.06 
                 1.2% 
                   
               
               
                 CE-1 
                 19 
                 Upper central 
                 5.34 
                 0.61 
                 11.3% 
                   
               
               
                 CE-2 
                 33 
                 Lower anteriors 
                 3.14 
                 0.28 
                 8.7% 
               
               
                   
               
             
          
         
       
     
         [0105]    All of the patents and patent applications mentioned above are hereby expressly incorporated into the present disclosure. The foregoing invention has been described in some detail by way of illustration and example for purposes of clarity and understanding. However, various alternatives, modifications, and equivalents may be used and the above description should not be taken as limiting in the scope of the invention which is defined by the following claims and their equivalents.