WO2006058162A2 - Orthodontic brackets having different adhesives and methods and appliances therewith - Google Patents

Abstract

Orthodontic brackets (30) and other orthodontic appliances have a pre-applied or factory-applied adhesives (40) thereon. The brackets (30), which may be plastic, metal or ceramic, have a bonding base surface to which an appropriate adhesive composition is applied or pre-applied. The adhesive (40), which is uncured, is curable, for example, by exposure to ultraviolet light. Preferably, a pre-applied adhesive (40) presents a non-tacky surface. An orthodontic appliance is assembled of a set of a plurality of brackets (30), one for each of a plurality of different teeth of a patient. The brackets (30) of the set may be of the same or different materials. The adhesives (40) on each of the different brackets (30) of the set are of more than one type, and maybe selected application or for pre-application on the individual brackets (30) based on the teeth to which they are to be bonded, the material of which they are made, some other criteria or a combination thereof. Adhesive Compositions for orthodontic brackets, comprising Bis-GMA, EBADMA, TIGDMA, CQ and a silica-based filler, are also disclosed.

Description

ORTHODONTIC BRACKETS HAVING DIFFERENT ADHESIVES AND METHODS AND APPLIANCES THEREWITH

[0001] This application is related to U.S. Patent No. 5,810,584 and U.S. Provisional Patent Application Serial No. 60/630,428, filed on November 23, 2004, both of which are hereby expressly incorporated by reference herein. Field of the Invention

[0002] This invention relates to orthodontic appliances, orthodontic adhesives and particularly to the bond strengths required to adequately secure orthodontic appliances, for example, orthodontic brackets, to teeth. Background of the Invention

[0003] The most widespread and useful form of orthodontic treatment employed today is fixed appliance therapy in which appliance components, such as orthodontic brackets, are bonded to a patient's teeth with the intention of having them remain there throughout the course of the treatment. For fixed appliance therapy, it is important to maintain the integrity of the bond throughout treatment.

[0004] A wide variety of dental composite materials available are for orthodontic bonding. For general bonding applications, a soft, flowable and user- friendly orthodontic adhesive is regarded as highly preferable by most treating orthodontic practitioners. With such adhesives, bond failures occasionally result, particularly with brackets that are bonded to teeth in the posterior section of the mouth where mastication forces are the highest.

[0005] While the generally preferred orthodontic adhesives suit the vast majority of appliance attachment procedures, the use of very highly filled, heavy- bodied materials can improve retention significantly. With such adhesives, overall bond failure rates can be reduced without significant changes in bonding procedures. This class of adhesives generally consists of dental restorative composite, e.g. POINT 4 brand, manufactured by Kerr Corporation, or P-50, manufactured by 3M Corporation.

[0006] Use of these highly filled, heavy-bodied adhesives has not been readily accepted by practitioners. One reason is that their packaging is not convenient for orthodontic use in that a relatively large orifice syringe with a screw plunger often delivers an excess quantity of composite, and is very clumsy, time consuming, and wasteful when attempting to apply the adhesive directly to the bracket bonding base. Further, the increased difficulty of application to the bracket bases due to the higher viscosity of the adhesive, plus relatively high precision pressure needed to seat the bracket on the tooth accurately, make the use of such adhesives impractical for full arch bonding.

[0007] One solution is for the treating orthodontic practitioner to use the highly filled, heavier-bodied adhesives, but to limit their use to suspect retention situations, in posterior and in-occlusion sites. One drawback of using multiple adhesive types is the expense and inconvenience of having to inventory extra bonding materials. The increased handling, chair time and overall inefficiency in using multiple adhesives on a given case is considered undesirable by most treating practitioners. It generally may not be practical for a clinician to inventory bracket- specific adhesive.

[0008] Also, where an appliance is constructed of brackets of different materials for use on different teeth, such as where structurally strong metal brackets are used on posterior teeth and more aesthetically appearing plastic or ceramic brackets are used on anterior teeth, one adhesive is not always most suitable for use with all of the brackets of different materials. In such cases, the drawbacks of using different adhesives as discussed above also apply.

[0009] Accordingly, the use of orthodontic adhesives that are most suitable for bonding brackets to teeth, and the use of such adhesives in treatment, has been subject to compromises. Improvement in this area is needed. Summary of the Invention

[0010] One objective of the present invention is to provide a system and method for efficiently bonding orthodontic brackets to teeth while minimizing bond failure. A further objective of the invention is to provide such a system and method that uses the adhesive most suitable for bonding the individual brackets to the patient's teeth. Yet another objective is to provide adhesives having improved bonding characteristics for brackets of different materials to enhance adhesion characteristics for particular bracket placements in the mouth. Such adhesives may or may not be "factory-applied;" i.e.,. the different adhesives may be applied chairside by the clinician, they may be pre-coated onto the brackets, or various combinations of each. Moreover, such adhesives may be single-component or dual-component type adhesives that are light-curable, self-curing, or dual cure (both light-curable and self- curing). All of these objectives are for the underlying purpose of maintaining bond integrity throughout the treatment.

[0011] According to principles of the present invention, a set of orthodontic brackets is provided for the treatment of a patient with the brackets coated or pre- coated with an appropriate adhesive. Each bracket of the set is configured for bonding to a different one of the patient's teeth. Different brackets of the set are coated or pre-coated with adhesives of at least two different types.

[0012] According to certain aspects of the invention, brackets of the set for one group of teeth are coated or pre-coated with an adhesive of one type, while brackets of the set for another group of teeth are coated or pre-coated with an adhesive of another and different type. For example, brackets of the set that are configured for posterior teeth may be coated or pre-coated with an adhesive of the highly filled, heavy-bodied or viscous type, while brackets of the set that are configured for all other teeth may be coated or pre-coated with a soft, flowable and user-friendly orthodontic adhesive.

[0013] More than two types of adhesives may be used to coat or pre-coat more than two groups of the brackets of any given set, based on the teeth to which the brackets are configured to be attached, to accommodate, for example, the particular forces to which the different teeth are likely to be subjected. Also, brackets of the set may be formed of different materials, some of metal or different metals (e.g., stainless steel and titanium), some of plastic (e.g., polycarbonate), some of ceramic. The respective brackets may be coated or pre-coated with adhesives that are most appropriate for the material of which the bracket is made. [0014] Different brackets may also be provided with bonding bases of different sizes or physical shape, which, because of their different surface areas and different force or moment-resisting dimensions, would be most reliably bonded with adhesives of different types.

[0015] The above and other differences among brackets and teeth may be used alone or in combination as the basis for selecting the adhesives with which the brackets are to be coated or pre-coated.

[0016] According to aspects of the present invention, formulations of adhesives are used that are appliance-specific or tooth-specific or both. One basis for the selection of the adhesive formulation is to boost the bond strength to maximums. However, there are occasions where the bond strength may be too high as a result of the bracket type and retention mechanism, and the basis of the selection may be to limit the bond strength, to enhance the ultimate removal of the bracket from the tooth at the end of the treatment, for example.

[0017] The use of bracket-specific or tooth-specific adhesives by way of factory-applied or other pre-coated brackets overcomes the negative aspects of using different adhesives on the brackets on different teeth of a patient. In situations where some or all of the adhesives are not pre-coated, advantages are obtained by way of having tailored bond strengths for the brackets on different teeth of a patient.

[0018] These and other objectives and advantages of the present invention will be more readily apparent from the following detailed description. Brief Description of the Drawings

[0019] Fig. 1 is a perspective view of a packaged set of adhesive-pre-coated orthodontic brackets according to one embodiment of the present invention. [0020] Fig. 2 is a cross-sectional view along line 2-2 of Fig. 1 illustrating an orthodontic bracket of the packaged set of adhesive-pre-coated orthodontic brackets.

[0021] Fig. 3A is a perspective view of one of the adhesive-pre-coated orthodontic brackets of the set of Fig. 1.

[0022] Fig. 3B is a perspective view, similar to Fig. 3 A, but of another and different one of the adhesive-pre-coated orthodontic brackets of the set of Fig. 1. Detailed Description

[0023] In accordance with principles of the present invention, a combination of tooth-specific or bracket-specific adhesives is utilized on different brackets of an appliance set for a given patient, in part in order to optimize bond integrities. The set of brackets is provided with pre-coated adhesives, factory applied by the appliance supplier or manufacturer, who applies the respectively prescribed adhesives that are deemed suitable for the different brackets of a set.

[0024] Fig. 1 illustrates a packaged set 10 of adhesive-pre-coated orthodontic brackets, according to one embodiment of the present invention, in a form in which the set of brackets is received by a treating orthodontic practitioner from an orthodontic appliance manufacturer for orthodontic treatment of a patient by the practitioner with an appliance formed of the bracket set. The package set 10 may take any of several forms, and is illustrated in a simplified form for purposes of more clearly illustrating certain features of the present invention. The packaged set 10 includes a set of orthodontic brackets 30 that are assembled for use in forming an orthodontic appliance for treatment of a given orthodontic patient. The set 10 may typically include one orthodontic bracket for bonding to each of a plurality of the teeth of the patient, and includes twenty-eight brackets in the example shown in Fig. 1.

[0025] In the set 10, each of a patient's teeth, from the left second molar through the centrals to the right second molar, for each of the upper and lower teeth of the patient, have a specifically configured orthodontic bracket. These twenty-eight brackets are each contained in an assigned cavity 12 in a plastic tray- like package 14. The cavities 12 may be arranged in the tray in the order in which the teeth to which they correspond are arranged in the patient's mouth. In the example shown in Fig. 1, the fourteen brackets 30 for the upper teeth of the patient are packaged in cavities 12 arranged along a row 21 in the package 14, while the fourteen brackets 30 for the lower teeth of the patient are packaged in cavities 12 arranged along a parallel row 22 in the package 14. The cavities of each row 21, 22 are divided on the centerline 16 of the package into two groups of seven cavities each in which are packaged each of seven brackets 30 for one of the respective quadrants of the patient's teeth. The brackets 30 for the patient's upper left quadrant of teeth are located in cavity positions 23a through 23g, for the upper left central, lateral, cuspid, first bicuspid, second bicuspid, first molar and second molar of the patient. Similarly, brackets 30 for the patient's upper right, lower left and lower right quadrants of teeth are located in cavity positions 24a through 24g, 25a through 25g, and 26a through 26g, respectively.

[0026] In each cavity 12, a bracket 30 is packaged in a way that preferably, but not necessarily, orients the bracket 30 in a specific orientation to facilitate easy pick-up by the practitioner. A pre-applied layer of adhesive 40 coats the base of the packaged bracket 30. The bracket 30 is shown in one such packaging arrangement in Fig. 2, in which an elastic foam insert 13 compresses against opposite sides of the bracket 30 to suspend it away from the walls and bottom of the cavity 12. A non¬ stick layer 15 may also protect against contact of the bracket base with the bottom of the cavity 12. A peal-off lid 17 covers each cavity 12 and seals the bracket 30 therein. Since the pre-applied adhesive on the bracket is typically of the type that is curable by exposure to ultraviolet light, the cavities 12, including the lids 17 and tray 14, are opaque to the frequency of UV light that cures the adhesive. For example, a metal foil layer of the tray 14 and lids 17 can serve this purpose.

[0027] Figs. 3A and 3B show two brackets 30, referred to as brackets 31 and 32, respectively, of the set 10, each of which is factory pre-coated with different respective adhesives 40, referred to as adhesives 41 and 42 respectively, coating their bases. The bracket 31 is for a different tooth than the bracket 32. By way of example, bracket 31 may be for the lower left first molar of the patient and contained in cavity position 25b of the package 14, where bracket 32 may be for the upper right central of the patient and contained in cavity position 24a of the package 14.

[0028] According to an embodiment of the invention, the bracket 31 is factory pre-coated with adhesive 41, which is of a first type, where the bracket 32 is factory pre-coated with adhesive 42, which is of a second type that is different than that of adhesive 41. In this exemplary embodiment, all brackets 30 of the set 10 for posterior teeth of the patient may be pre-coated with the adhesive 41 while all brackets of the set 10 for anterior teeth of the patient may be pre-coated with the adhesive 42. In Fig. 1, the brackets 30 for the posterior teeth may be regarded as those in groups 43 of the cavities 12, in positions d-g of quadrants 23-26, where brackets 30 for the anterior teeth may be regarded as those in groups 44 of the cavities 12, in positions a-c of quadrants 23-26. In this example, all brackets are assumed to be made of the same standard stainless steel or other metal. For this example, the adhesive 42 may be taken as a Standard orthodontic adhesive, that is, one commonly used by practitioners for bonding all orthodontic brackets of a set, while the adhesive 41 may be referred to, for purposes of this description, as a non-standard adhesive, that is, one not commonly used for all orthodontic brackets of a set.

[0029] A non-standard adhesive may be provided on certain brackets or on certain teeth to increase bond strength where needed. For example, heavier bodied adhesive materials are found to improve bracket retention, even though examination of the chemical formulation of such heavier adhesives suggests the chemical make-up is not necessarily responsible for the improvement of the molecular affinity for tooth enamel compared to conventional orthodontic bonding materials. Such restorative composites that are available to a practitioner, who seeks to apply such an adhesive to particular brackets when installing the brackets on a patient, usually contain additives that are unnecessary for orthodontic bonding and may impair the ability of the adhesive to completely cure. For example, restorative composites typically contain opacifying agents and colorants to match the shade of enamel, and these additives effectively block the light curing reaction to some degree. The factors that seem to contribute to improved retention are the handling characteristics and the cohesive strength of the composite. Regarding the handling characteristics, the very heavy body of the material may allow the placement and related clinical procedures prior to curing to be improved so that the bond interfaces are of very high integrity. Subsequently, if the clinician makes allowance to fully cure the material, the cohesive strength, as measured in the laboratory as compressive strength and diametral tensile strength, will typically be higher than conventional orthodontic adhesives. The complexity of such a procedure generally will deter the application of such adhesives by the treating practitioner.

[0030] On the other hand, a particular advantage of a factory applied adhesive is control over the formulation such that all the attributes of proper handling characteristics can be retained, plus all the unnecessary additives can be removed so that the material will cure faster and more thoroughly. Such an adhesive may be the factory pre-coated adhesive 41 used on brackets 31.

[0031] The bond attachment mechanism described above is primarily mechanical in nature. This and other properties of adhesives are responsible for the differences among adhesives and their particular properties and suitabilities for different brackets and different teeth. It is contemplated that retention could be improved further by the use of adhesion promoting constituents, particularly resin components known to have enhanced attraction to enamel and metallic substrates. In this way a combination of mechanical interlocking supplemented with chemical bonding will increase bond integrity favorably. Some examples of adhesion promoting monomers include n-phenyl glycin-glycidyl methacrylate, 4- methacryloyloxyethyl trimellitate anhydride, methacryloxyethyl hydrogen phenyl phosphate, Bis GMA-bis chlorophosphate, glycerol phosphate dimethacrylate, and pyromellitic glyceroldimethacrylate.

[0032] While each of such adhesives has its own specific attraction or reactivity toward certain substrates, all function similarly; they are typically bifunctional molecules having at least one methacrylate group that can participate in the polymerization (setting) reaction, and at least one other reactive group that can create a chemical bond to enamel and the metallic appliance. The filler may also contain reactive species that may chemically interact with the bond substrate. This is typically an organic or semi-organic constituent used as a minor component of the filler matrix having little or no significant contribution to the cohesive strength of the composite, but offering added chemical attraction bond enhancement to the substrate. In this case there would be essentially no participation with the polymerization curing reaction and low chemical reactivity toward the resin matrix, however physical entanglement would integrate the material homogenously. Examples of this class of material are polyacrylic acid and polymethacrylic acid. These polymers are known to promote adhesion to enamel and stainless steel when used in glass ionomer band cement.

[0033] In some cases it may be desirable to provide the brackets of the set 10 with brackets 31 made of one material and brackets 32 for a different tooth made of another material, hi such cases, the different adhesives 41 and 42 for the different brackets may be selected, rather than to provide increased bond strength in different parts of the mouth, to more suitably bond brackets of different materials to different teeth.

[0034] Similarly, the adhesion to other common dental materials may also be enhanced by selection of an appropriate adhesion promoter. Some other substrates of interest are polycarbonate and related plastic/composite bracket materials, alumina and related ceramic bracket materials, and porcelain, gold, composite veneer or other restorative materials.

[0035] Chemically active bifunctional monomers should be placed in intimate contact with the surface to which the enhanced bonding is desired. This is generally not an issue with lower viscosity materials in the range of water (e.g., sealants) to moderately highly filled pastes (e.g., orthodontic adhesives), as there is sufficient resin to effect wetting and place the reactive groups in sufficiently close proximity. However, very highly filled composites may have a "dry" or non-tacky characteristic that limits substrate wetting. Therefore, it is further contemplated that posterior bonding adhesives would benefit from wetting agents which could include reactive or spectator varieties. Examples of reactive types are glycerol dimethacrylate, hydroxyethyl methacrylate, methyl methacrylate, ethyl methacrylate, and tetrahydrofurfuryl methacrylate. Spectator or non-reactive agents can include solvents and surfactants, for example ethanol, acetone, sodium dodecyl sulfate, tetrapotassium polyphosphate, and nonylphenoxypoly(ethyleneoxy)ethanol.

[0036] Whereas in the above description, the ability of different formulations to boost the bond strength to maximums is discussed, there are occasions where the bond strength may be too high as a result of the bracket type and retention mechanism. An example combination is the use of a ceramic bracket with a high quality orthodontic bonding adhesive. Ceramic brackets may be composed of very high purity alumina oxide and can have a mechanical, quasi-chemical bonding base that features exceptionally large undercut surface area, and at the same time posses a highly charged (electrochemically active) surface that is ripe for elevated chemical attraction with a bonding adhesive. Due to the unique combination of design and material properties, the bond strength may occasionally exceed desirable de-bonding forces thus placing the enamel at risk of fracture. By engineering the adhesive to fail at a threshold level, the highest de-bonding forces may be suppressed or eliminated. While it is generally not practical for a clinician to inventory bracket-specific adhesive, it is an ideal opportunity for a manufacturer to provide an appliance with bonding material that will maximize safety. Some possibilities for engineering an adhesive of this type may include the use of low strength organic filler/polymer as at least part of the filler make-up, use of low strength inorganic filler (e.g., hollow glass microspheres) as at least a percentage of the filler make-up, modification of filler treatment to reduce the bonded interface between the filler particle and the resin matrix, non-reactive additives that interrupt or reduce the overall strength of the resin matrix, or use of reactive resins that have inherently low strength. Alternatively, the manufacturer may provide a laminate configuration whereby the separation strength at specified interfaces can be well controlled. EXAMPLE 1

[0037] One formulation of a light-cure posterior bonding adhesive of high strength is as follows:

EXAMPLE 2

[0038] One formulation of a light-cure, low strength bonding adhesive for other teeth is as follows:

EXAMPLE 3

[0039] The following formulations are believed to be well-suited for bonding plastic appliances:

Tensile bond strength test

[0040] To determine the adhesive strength, Ormco Damon 3 orthodontic brackets (polycarbonate plastic bonding base) part number 491-4520 were tested as follows: Bovine teeth were encapsulated in acrylic and the facial enamel surface was sanded flat with 600 grit sandpaper. This surface was etched 30 seconds with 37% phosphoric acid, washed with tap water, then dried with compressed air. A thin coating of Ormco Ortho Solo sealant was brushed on. A small dollop of the Example 3 paste adhesive formulation was applied to the base of the Damon 3 bracket, then the bracket was immediately positioned on the prepared tooth surface. Excess adhesive was removed and the assembly was light cured for 20 seconds using a Demetron 501 dental curing light having output 550 mw/cm2.

[0041] The bonded bracket was immediately prepared for tensile bond strength (TBS) testing. A 0.016 inch diameter round archwire was placed in the slot of the bracket and ligated using 0.009 inch diameter ligature wire. The bovine tooth/bracket sample was held with an appropriately designed fixture in the lower jaw of an Instron physical test machine, while the ends of the archwire were clamped in the upper jaw. This arrangement allowed the bracket to be lifted directly up 90 degrees from the tooth surface creating a tensile force. The cross-head connected to the upper jaw was programmed to move upward at 0.1 inch/minute and the load to displace the bracket from the tooth was recorded.

Note 1 : Enlight is a conventional, general-purpose light-cured bonding adhesive having resin composition Bis Gma and EBADMA. It has no special additives for enhanced adhesion. Note 2: Transbond XT is a conventional, general-purpose light-cured bonding adhesive marketed by 3M UnitekCorproation. EXAMPLE 4:

[0042] Another adhesive composition, which includes PMGDM, is also contemplated. Set forth below is an example formulation, although it does not perform quite as well as the formulation tested in Example 3, above.

[0043] The shear bond strength (SBS) was determined by a method similar to Example 3. Instead of the archwire ligated into the bracket slot, the sample was oriented 90 degrees from Example 3, and the archwire was lopped under the tie wings of the bracket thereby producing a shear force along the plane of the tooth surface as the Instron cross-head was moved upward.

EXAMPLE 5

[0044] The following dual-component formulation is designed for enhanced adhesion to stainless steel and titanium. The composition is currently marketed under the trade name MAXCEM by the Kerr Corporation.

[0045] The shear bond strength of the Example 5 formulation was determined & ,-. by a method similar to Example 4. Instead of bovine teeth, either stainless steel or titanium metal substrates, polished flat to 600 grit, were used. A button of the mixed Example 5 paste material was formed from a cylindrical mold of diameter 2.5mm _v. '.? placed on the substrate with the paste in direct contact with the substrate, as representative of placing adhesive directly on the mesh base of a stainless steel or titanium orthodontic bracket. The paste material was dual cured, i.e., allowed to self cure, and was also light cured as in Examples 3 and 4. In a like manner to the archwire being looped under the tie wings of the bracket, the wire was looped under the cured button, thereby producing a shear force as the Instron cross-head was moved upward.

[0046] The foregoing results suggest specificity of the chemistries toward certain substrates. In addition to the GPDM/GDM chemistry for metal bonding enhancement, other additives that are known to have enhanced attraction to metallic substrates include: 4-methacryloxyethyl trimellitic anhydride (4-META), methacryloxy hydrogen phenyl phosphate (phenyl-P), and methacryloyloxydecyl dihydrogen phosphate (MDP-10).

[0047] Variations on the formulation set forth in Example 5 are also contemplated. Such variations generally fall within the ranges set forth below for the noted components. It should be understood that the formulations set forth below omit : certain components contained in the Example 5 formulation because those components are not considered necessary to enhance the adhesive characteristics. Moreover, the fillers in Example 5 are grouped together in the formulations below.

[0048] It is also contemplated to improve the bond strength of the adhesives through modification of the polymer and/or filler materials. In the case of the polymer, the resin matrix may be tailored toward certain engineering properties, e.g., improved toughness. One approach may be to use a shock absorbing capable material like polyurethane that will dissipate the energy. Another approach may be the use of ^■ plasticizer(s) to reduce the modulus of the otherwise brittle and rigid adhesive interface. In regard to filler, the same ideas apply. The filler generally makes up the bulk of the adhesive composition, typically 60% to 80% by weight. Thus there is the opportunity to replace some or all of the normally glassy-like characteristic with more pliable or shock absorbent material. It is theorized that many bond failures are due to impact forces, so the ability of an adhesive to absorb and dissipate shock energy without fracture may improve bond reliability significantly.

[0049] It is also envisioned to provide specific adhesives for the third general class of appliance (bracket) material, ceramic. Generally, there are various known approaches to maximize bond strengths, both from a bracket design perspective and from a chemical reactivity standpoint. However, due to the extremely high modulus (rigidity) of ceramic materials, there is a great danger of damaging enamel upon removal of the appliance if the bond strength is too high. Novel formulations are contemplated that have inherently relatively low strength of the fully cured material by the mechanism of chain transfer that limits the growth of the polymer molecular weight during the curing (polymerization) process. It is also contemplated that use of low strength and/or specially treated fillers would produce a threshold stress at which there will be initiation of catostrophic crack propogation.

[0050] The invention has been described in the context of exemplary embodiments. Those skilled in the art will appreciate that additions, deletions and modifications to the features described herein may be made without departing from the principles of the present invention. Accordingly, the following is claimed:

Claims

the following is claimed: 22

1. An orthodontic appliance set comprising: a plurality of orthodontic brackets, each configured for mounting on a different one of each of a plurality of a patient's teeth; . each of a plurality of the brackets having a bracket base configured for bonding to a tooth of the patient, each base having adhesive pre-applied thereto; the adhesive pre-applied to at least two of the bases being of different types; and the plurality of brackets being commonly packaged for delivery to a practitioner for bonding to the teeth of the patient; wherein said adhesive pre-applied to at least one bracket base having the following composition:

and said adhesive pre-applied to at least one bracket base having the following composition:

2. The orthodontic appliance set of claim 1 wherein: at least two of the brackets are made of different materials and the adhesive pre- applied to each is of a different type at least in part based on the material of which the bracket to which the adhesive is pre-applied is made.

3. The orthodontic appliance set of claim 2 wherein: at least two of the brackets have bracket bases configured for bonding to different teeth of the patient and the adhesive pre-applied to each is of a different type at least in part based on the tooth to which the bracket is to be bonded.

4. The orthodontic appliance set of claim 1 wherein: at least two of the brackets have bracket bases configured for bonding to different teeth of the patient and the adhesive pre-applied to each is of a different type at least in part based on the tooth to which the bracket is to be bonded.

5. The orthodontic appliance set of claim 1 wherein: brackets of the plurality have an adhesive composition applied to the base thereof presenting a substantially non-tacky surface.

6. The orthodontic appliance set of claim 1 wherein: brackets of the plurality have an adhesive composition applied to the base thereof presenting a tacky surface and a layer of particles secured to the tacky surface of the adhesive composition so as to present a substantially non-tacky surface.

7. The orthodontic appliance set of claim 1 wherein: the brackets of the plurality are made of a material selected from the group consisting of metal, plastic and ceramic.

8. The orthodontic appliance set of claim 1 wherein: said adhesive composition has a substantially long-term shelf life in an uncured state.

9. An adhesive composition for orthodontic brackets, comprising:

10. An adhesive composition for orthodontic brackets, comprising:

11. An adhesive composition for orthodontic brackets, comprising:

12. An adhesive composition for orthodontic brackets, comprising:

13. An adhesive composition for orthodontic brackets, comprising:

14. An adhesive composition for orthodontic brackets, comprising: