Indirect bonding tray featuring stable bracket positioning and easy adhesive cleaning

Abstract

An indirect bonding tray includes a tray body configured to fit a patient's dental arch and a plurality of modules attached to the tray body with at least one flexible material. Each module defines a receiving well having sidewalls, at least one detent, a plurality of support surfaces, and a plurality of slits configured to permit elastic deformation. The detents and support surfaces are configured to retain an orthodontic bracket in a predetermined position while providing tactile feedback upon insertion. The receiving wells are configured to provide a clearance around bracket pads to facilitate the removal of excess adhesive.

Description

Attorney Docket No.: 47327.0006 PCTINDIRECT BONDING TRAY FEATURING STABLE BRACKET POSITIONING AND EASY ADHESIVE CLEANINGCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority under 35 U.S.C §119(e) to U.S. Provisional Application, U.S.S.N. 63 / 746,208, filed lanuary 16, 2025, which is incorporated herein by reference.FIELD

[0002] Embodiments of the present invention relate to the field of medical instruments. More specifically, the exemplary embodiments of the present invention relate to processing and fabricating orthodontic apparatus.BACKGROUND

[0003] Indirect bonding (IDB) trays are orthodontic devices designed to streamline the process of bracket placement by pre-positioning brackets in an accurate, predetermined position on a model of the patient's teeth. These trays allow multiple brackets to be bonded simultaneously, reducing chair time, improving precision, and enhancing treatment outcomes.

[0004] In the 1970s, indirect bonding was first introduced by Dr. Thomas F. Mulligan as an alternative to direct bonding, which often led to inconsistencies in bracket placement. Initial techniques involved labor-intensive processes such as wax or thermoplastic trays, which limited adoption due to high complexity and inconsistency in bonding reliability. During the 1990s and 2000s, improvements in adhesives and transfer trays helped standardize the process. Since the 2010s, with the advent of CAD / CAM technology and 3D printing, indirect bonding has become more efficient. Today, many orthodontists rely on digital scans and customized bonding trays to enhance the accuracy and efficiency of the bracket bonding procedure.Attorney Docket No.: 47327.0006 PCT

[0005] There are many advantages of indirect bonding trays in the orthodontic field. For example, when brackets are first positioned on a digital or physical model of the patient's teeth, indirect bonding trays can ensure exact placement for optimal force application to reduce human error compared to direct bonding. The indirect bonding trays can also reduce chair-side time during appointments and improve patient comfort to achieve time efficiency when multiple brackets are bonded simultaneously. By ensuring accurate bracket placement, indirect bonding improves alignment and can also reduce the need for mid-treatment adjustments and wire bending. Moreover, the indirect bonding trays can reduce ergonomic strain by minimizing the time spent working inside the patient's mouth, and shorter bonding sessions and fewer adjustments throughout treatment contribute to a more pleasant patient experience.

[0006] While indirect bonding products offer several advantages, they also present challenges that can impact clinical outcomes and workflow efficiency. Below are the key issues associated with current indirect bonding products.

[0007] 1. Accuracy issues and bonding failures

[0008] Despite careful planning, the indirect transfer process can still lead to minor bracket misalignments due to movement during tray placement or adhesive handling. If the adhesive is not applied evenly or bubbles form, it can cause brackets to debond prematurely. Incomplete curing can result in poor adhesion, especially in hard-to-reach areas.

[0009] 2. Tray fit issues of distortion of physical trays and inaccurate digital trays:

[0010] For distortion of physical trays, thermoplastic or silicone trays can warp during fabrication, leading to a poor fit on the patient’s dentition. This problem is especially common when using stone models that may chip or distort over time. For inaccurate digital trays, intraoral scans must be flawless. Any scanning errors (e.g., missing contact points) orAttorney Docket No.: 47327.0006 PCTinaccurate printing may cause misfitting trays. Variations in the thickness of printed trays can affect flexibility and retention.

[0011] 3. Adhesive contamination and handling challenges

[0012] Moisture contamination during the bonding process (from saliva or breath) can compromise adhesion, leading to bracket failure. Unlike direct bonding, with indirect bonding, the brackets are already loaded into the tray, increasing the risk of adhesive contamination while handling the tray. Some indirect bonding products involve pre-loading adhesive on brackets, which can dry out or shift within the tray if not handled properly. This adds complexity to the procedure.

[0013] 4. Limited flexibility in adjustments

[0014] Since bracket positions are pre-planned and pre-set, there is a limited opportunity for real-time adjustments during bonding. If a tray doesn’t fit perfectly, the orthodontist must decide whether to proceed with bonding or create a new tray, which adds delays and costs. Most indirect bonding products are designed for single-use only, meaning any error requires the fabrication of a new tray, adding to overhead and material waste.

[0015] 5. Complexity and training requirements

[0016] Mastering indirect bonding techniques requires additional training for orthodontists and staff. Poor handling or tray positioning can compromise accuracy and outcomes. Digital workflows involving scanning, CAD software, and 3D printing introduce several points of failure and require both equipment and staff training. Errors in digital tray design or printer calibration can lead to repeated adjustments and wasted materials.

[0017] While indirect bonding products offer several benefits, such as enhanced precision, efficiency, and patient experience, the challenges associated with accuracy,Attorney Docket No.: 47327.0006 PCThandling, and flexibility remain areas of concern. From their humble beginnings in the 1970s to modern, digitally integrated workflows, these trays offer a streamlined approach to orthodontic bonding. With 3D printing and CAD / CAM technology, indirect bonding continues to evolve. Innovations in digital workflows, training, and materials will help address these issues, making indirect bonding products even more effective and accessible for orthodontists.SUMMARY

[0018] To address some of these issues, the present invention discloses a system aimed at improving bonding success and accuracy.

[0019] Bonding failure is one of the issues that prevents the adoption of IDB by doctors. Immediate bonding failure will negatively affect the bonding time, as the debonded brackets have to be bonded with a direct or indirect bonding technique again at the same appointment. Premature bonding failure during the treatment will cause additional bonding appointments and increase operational costs for the doctor.

[0020] This disclosure relates to an indirect bonding tray of the present invention. In one example, the disclosure is directed to the indirect bonding tray comprising: a tray body and a plurality of modules. The modules further comprise a receiving well for receiving a bracket, at least one detent configured to provide a retentive force on the bracket, a plurality of support surfaces for defining a seated position of the bracket, and a plurality of slits for providing elastic deformation to the module.

[0021] In one aspect of this embodiment, the module is integrally formed with the tray body. The slits extend from the receiving well toward the sidewalls of the receiving well to facilitate bracket insertion. Notably, the receiving well of each module is dimensioned suchAttorney Docket No.: 47327.0006 PCTthat when the bracket is inserted, a clearance is created between the bracket pad and the module. This clearance is configured to provide an accessible space for cleaning excess adhesive and allow light penetration for curing.

[0022] In another aspect of this embodiment, the tray body further comprises a lingual part, and each module further comprises a buccal part, the lingual part and the buccal part configured to be detachably coupled to each other via a stud and a corresponding locating hole. The buccal part is configured to separate from or pivot relative to the lingual part to facilitate the loading of the bracket into the receiving well and may be composed of a material different from the lingual part to optimize the balance between bracket retention and tray flexibility.

[0023] In another aspect of this embodiment, each module further comprises a clip detachably coupled to the tray body via a positioning post and a corresponding positioning hole of the tray body. The clip defines the receiving well and may be composed of a material different from the tray body to optimize the balance between bracket retention and tray flexibility.

[0024] In another aspect of the present invention, a method for using the indirect bonding tray system is disclosed. The method involves assembling brackets into modules with tactile feedback, cleaning adhesive flash through a defined clearance, and generating controlled bonding pressure via a cantilever beam deflection of the module. The method further ensures easy tray removal by utilizing elastic deformation provided by slits in the module.

[0025] To improve bonding success rate and accuracy, the following features are built into the system: the clearance around the bracket pad that allows light curing and adhesive flash cleaning without interference; controllable pressure between the bracket pad and the tooth surface; holding of the bracket body along its perimeter; and the slits arranged in theAttorney Docket No.: 47327.0006 PCTreceiving well walls for easy tray removal. Each feature is explained in detail below. At the system level, they work together to achieve improved bonding success and accuracy.Specifically, the clearance around the bracket pad improves the curing result of the adhesive, which reduces the bonding failures. The pressure between the bracket pad and the tooth surface is also controlled to increase the bonding strength and success. The holding mechanism around all sides of the bracket body ensures the grip force is strong, and the bracket is stable inside its receiving well, which can achieve higher accuracy in its position relative to the tooth surface. The slits in the receiving well will make its sidewalls deflect in favor of the insertion and separation of the bracket under insertion force and peeling force.

[0026] Additional features and benefits of the exemplary embodiment(s) of the present invention will become apparent from the detailed description, figures, and claims set forth below.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The exemplary embodiment(s) of the present invention will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the invention, which, however, should not be taken to limit the invention to the specific embodiments, but are for explanation and understanding only.

[0028] FIG. 1A is a perspective view illustrating a two-part indirect bonding (IDB) tray for an upper arch in three segments in accordance with a second embodiment of the present invention.

[0029] FIG. IB is a perspective view illustrating a one-body IDB tray for an upper arch in two segments in accordance with a second embodiment of the present invention.

[0030] FIG. 2 is a partial enlarged view of FIG. IB, illustrating each module configured to hold a body of a bracket while providing a clearance for a bracket pad.Attorney Docket No.: 47327.0006 PCT

[0031] FIG. 3 is a sectional perspective view illustrating the module containing the bracket and contacting a buccal side of a tooth surface, wherein a gap is formed between the module and the tooth surface.

[0032] FIG. 4A is a partial enlarged view of FIG. 2, illustrating detents and supports disposed along four sidewalls of a receiving well.

[0033] FIG. 4B is a partial enlarged view illustrating the bracket and the IDB tray before assembly.

[0034] FIG. 5 is a sectional view taken along a distal direction illustrating the bracket held by detents and supported by the support surfaces within the receiving well.

[0035] FIG. 6 is a sectional view taken along a gingival direction illustrating the engagement between the bracket and the module.

[0036] FIG. 7A is a top-down perspective view illustrating the two parts of IDB, with a buccal part and a lingual part engaged in three segments in accordance with a second embodiment of the present invention.

[0037] FIG. 7B is a perspective view of the second embodiment in an engaged state.

[0038] FIG. 8 is a partial enlarged view of FIG. 7B illustrating the segment from UR2 to UL2 with the buccal and lingual parts engaged in accordance with the second embodiment of the present invention.

[0039] FIG. 9 is a perspective view illustrating the module of FIG. 8 in a disengaged or extended state, showing the buccal part separated from the lingual part.

[0040] FIG. 10 is an enlarged view illustrating a stud on the lingual part.

[0041] FIG. 11 is an enlarged view illustrating the configuration of a locating hole on the buccal part.Attorney Docket No.: 47327.0006 PCT

[0042] FIG. 12 is a perspective view illustrating a module and a clip in an assembled state on the upper front teeth with two materials in accordance with a third embodiment of the present invention.

[0043] FIG. 13 is a perspective view illustrating the lingual view of the IDB segment on the upper front teeth without brackets in dual materials.

[0044] FIG. 14 is a perspective view illustrating the IDB segment on the upper front teeth with two materials and brackets placed in clips.

[0045] FIG. 15 is a perspective view illustrating the IDB segment on the upper front teeth without the clips.

[0046] FIG. 16 is a perspective view illustrating that each clip has a positioning post and a receiving well disposed on different surfaces.

[0047] FIG. 17 is a side sectional view illustrating the bracket engaged in the receiving well and the positioning post secured within the positioning hole to couple the clip with the module, wherein the clip and the tray body are made of different materials.Attorney Docket No.: 47327.0006 PCTDETAILED DESCRIPTION

[0048] Embodiments of the present invention are described herein in the context of a method and / or apparatus for processing and fabricating orthodontic devices.

[0049] The purpose of the following detailed description is to provide an understanding of one or more embodiments of the present invention. Those of ordinary skills in the art will realize that the following detailed description is illustrative only and is not intended to be in any way limiting. Other embodiments will readily suggest themselves to such skilled persons having the benefit of this disclosure and / or description.

[0050] In the interest of clarity, not all the routine features of the implementations described herein are shown and described. It will, of course, be understood that in the development of any such actual implementation, numerous implementation- specific decisions may be made in order to achieve the developer’s specific goals, such as compliance with application- and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be understood that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skills in the art having the benefit of embodiment(s) of this disclosure.

[0051] Various embodiments of the present invention illustrated in the drawings may not be drawn to scale. Rather, the dimensions of the various features may be expanded or reduced for clarity. In addition, some of the drawings may be simplified for clarity. Thus, the drawings may not depict all the components of a given apparatus (e.g., device) or method. The same reference indicators will be used throughout the drawings, and the following detailed description will refer to the same or similar parts.

[0052] For the present invention, the term “tactile feedback” is used herein to refer to a physical sensation or mechanical response perceptible to a user through the sense of touchAttorney Docket No.: 47327.0006 PCTduring the insertion of a bracket into a receiving well. This feedback, such as a “click” or a distinct stop in resistance, is generated by the interaction between the bracket and the flexible material of the tray or module, signaling to the user that the bracket has successfully reached the fully seated position without requiring visual confirmation.

[0053] For the present invention, the term “fully seated position” is used herein to refer to the specific orientation and spatial location of an orthodontic bracket within a receiving well of the indirect bonding tray, where the bracket is in physical contact with designated support surfaces (e.g., the first and second support surfaces). In this position, the bracket is securely held at a predetermined three-dimensional coordinate relative to the tray body, ensuring that the bracket's position on the patient’s tooth precisely matches the digital or physical treatment plan.

[0054] For the present invention, the term “attached to” is used herein to interpret in its broadest sense and encompasses both monolithic integration and multi-part assembly. Specifically, the plurality of modules being “attached to” the tray body may refer to the modules being integrally formed with the tray body as a single, continuous structure, or the modules being separate components that are subsequently coupled, joined, fastened, engaged, or otherwise secured to the tray body through mechanical engagement, adhesive bonding, or other coupling means.

[0055] The creation of an indirect bonding tray involves several steps, starting with impressions or digital scans of the patient’s teeth and ending with the fabrication of the custom tray. Below are the key steps for the traditional workflow and digital workflow:

[0056] For traditional workflow, physical impressions are taken using polyvinyl siloxane (PVS) or alginate and then poured into stone to create a working model, and brackets are manually positioned on a stone model using adhesive or wax. A transfer tray is made using thermoplastic material or silicone molds over the stone model with the pre-positionedAttorney Docket No.: 47327.0006 PCTbrackets. Some orthodontists use dual-layer trays, where the inner layer is soft (to hold brackets), and the outer layer is rigid (for structural integrity). The adhesive is pre-applied to the brackets within the tray, or it can be added just before bonding in the patient’s mouth. The choice of adhesive depends on the orthodontist’s preference (light-cure or dual-cure systems). After the tooth surface is properly prepared, the tray, loaded with brackets, is positioned on the patient’s teeth. With light curing, all brackets are bonded simultaneously, following which the tray is carefully removed, leaving the brackets in place.

[0057] For digital workflow, intraoral scanners are used to generate 3D digital models of the patient’s dentition. Bracket positions are determined in software (CAD) based on a virtual treatment plan. The treatment planning software ensures precise control of the position and orientation of the bracket on the teeth. With the treatment planning software, the IDB tray can be designed digitally. Customized IDB trays are 3D printed with receptacles to fit the patient’s teeth and features to hold brackets. The adhesive is pre- applied to the brackets within the tray, or it can be added just before bonding in the patient’s mouth. The choice of adhesive depends on the orthodontist’s preference (light-cure or dual-cure systems). After the tooth surface is properly prepared, the tray, loaded with brackets, is positioned on the patient’s teeth. With the adhesive cured, all brackets are bonded simultaneously, following which the tray is carefully removed, leaving the brackets in place. The digitally designed and 3D printed IDB tray has become the trend and is replacing the traditional fabrication of IDB trays.

[0058] However, one of the most noticeable issues of the 3D printed IDB tray is bracket debond, which means the bracket is not bonded to the tooth after the bonding process. One of the factors that can cause the debond is the incomplete seating of the IDB tray and brackets on teeth. If the IDB tray does not fully adapt to the dentition, the bracket pad can be in the wrong position and orientation, which leaves uneven thickness in the adhesive between the pad and the tooth surface. This uneven thickness can lead to an incomplete adhesive layer or reduced shear and tensile strength of bonding. Another factor that can contribute to theAttorney Docket No.: 47327.0006 PCTdebond is the positive pressing force from the IDB tray to the bracket pad onto the tooth surface.

[0059] There are at least three factors that contribute to the good seating of the IDB tray and brackets on teeth: the geometric interference, errors in the fabrication of the IDB tray, and material properties of the IDB tray. In general, there are rigid resin and soft (flexible) resin available for 3D printing of IDB trays. If the first two factors are assumed to be given, the rigid resin provides better shape accuracy and minimal deformation and lacks adaptability, whereas the soft resin offers better adaptability and lacks dimensional precision and stability. At their initial positions, teeth are often in a crowded state. Due to the complexity of the tooth surface, the seating of the tray is over-constrained by all the tooth surfaces in contact. So it is hard for a receptacle in the IDB tray to adapt to the corresponding tooth. If the material is too rigid, the IDB tray is hard to fit on the dentition and remove after bonding. If the material is too soft, the IDB tray is easy to deform and lose accuracy in bracket position and orientation when fitted onto the dentition. The present invention provides an IDB system of features that are embodied in flexible material and integrable with other portions of the IDB tray in rigid material. By integrating rigid and soft materials, the 3D printed IDB tray can adapt to the dentition and position the brackets more precisely, therefore improving the bonding success and accuracy.

[0060] On the other hand, the positive pressing force from the IDB tray to the bracket pad onto the tooth can be controlled by the designed interference between the two.Apparently, the material properties of the IDB tray and the seating of the IDB tray on dentition also affect the positive pressure between the bracket pad and the tooth.

[0061] It is worth mentioning that an IDB tray can be segmented into multiple pieces digitally or physically after 3D printing, such that each segment can fit on the dentition with ease, as shown in FIG. 1A and FIG. IB. For example, as shown in FIGS. 1A and 7 A, the IDBAttorney Docket No.: 47327.0006 PCTtray of the present invention is segmented into three segments, and segmentation can be done between UL2 and UL3 and between UR2 and UR3; as shown in FIG. IB, the IDB tray of the present invention is segmented at the middle plane and separated into two segments for the left and right sides of the arch.

[0062] At the high level, the generic shape of the cross-section of the IDB tray consists of the buccal part and the lingual part. One way to integrate the dual materials, soft and rigid, in one IDB tray is to build the soft structural component to hold the bracket, and the rest of the IDB tray body in a hard material. This structural component in soft material can take various forms as explained hereafter. The soft and hard structural components can be assembled into the IDB tray or fabricated in one 3D printing process. This disclosure explains three embodiments of the IDB tray for an upper jaw to demonstrate this development.

[0063] As used herein, the term “module” refers to a localized structural component of the indirect bonding tray in one material configured to interface with, receive, and releasably hold a bracket. Each module may be integrally formed with the tray body in one fabrication process, or it may be a component of a multi-part assembly comprising separable components such as a buccal part, a lingual part, or a detachable clip.

[0064] FIGS. 1 A to 2 depict the common components of an indirect bonding (IDB) tray 10 as may be constructed in accordance with the method disclosed herein. The indirect bonding tray 10 comprises a tray body 11 and a plurality of modules 12, wherein the tray body 11 is designed to conform to a patient's tooth. Specifically, the tray body 11 is configured for a patient-specific, customized fit with a plurality of teeth in a patient's dental arch. As shown in FIG.3, taking an IDB tray according to the present invention that is configured for a patient’s maxillary dental arch as an example; the tray body 11 of the IDB tray 10 is shaped in accordance with the lingual and occlusal surfaces of the patient’s teeth;Attorney Docket No.: 47327.0006 PCTthe module 12 is correspondingly shaped and sized to adapt to the curvature and dimensions of the patient’s teeth, and a gap 23 is formed between the module and the tooth surface. In various embodiments, the tray body 11 and the modules 12 may be attached, connected or associated with each other in any suitable manner. For example, the modules 12 may be integrally formed with the tray body 11 as a single, unitary structure. In other embodiments, the modules 12 and the tray body 11 may be provided as separate components and subsequently assembled, such as in a two-part embodiment in which the modules 12 are coupled to the tray body 11 by one or more mechanical engagement features. The manner in which the modules 12 is connected to or associated with the tray body 11 may be implemented using conventional attachment techniques, including but not limited to mechanical interlocking, snap-fit engagement, adhesive bonding, over-molding, co-printing, or combinations thereof. Accordingly, the specific connection or attachment method between the tray body 11 and the modules 12 is not limited to the illustrated embodiments and does not constitute a limitation of the present invention.

[0065] In the first embodiment of the present invention, the modules 12 and the tray body 11 are integrated into a monolithic segment that is formed by 3D printing, and are formed of at least one flexible material. In this embodiment, the tray body 11 and the modules 12 share similar material properties and rigidity while collectively providing sufficient flexibility for indirect bonding. In the second and third embodiments of the present invention, the tray body 11 and the modules 12 are also formed of flexible material but differ in rigidity. Specifically, the tray body 11 is formed of a first flexible material having a first rigidity, and the modules 12 are formed of a second flexible material having a second rigidity lower than the first rigidity. The first flexible material and the second flexible material of the present invention are distinguished based on their mechanical properties, particularly rigidity, Young’s modulus, or Shore hardness. The first flexible material possesses a higher rigidity to maintain the dimensional stability of the tray body 11 and the precision of the patient-specificAttorney Docket No.: 47327.0006 PCTdental fit. The second flexible material possesses higher flexibility and elasticity compared to the first flexible material to provide the necessary elastic deflection for the modules.Preferably, the selection of the first flexible material and the second flexible material may include, but is not limited to, photopolymers, thermoplastics, elastomers, or composites of the aforementioned materials. For example, the first flexible material may be a biocompatible photopolymer resin with higher rigidity BioMed Clear, BioMed Durable, or Dental LT Clear from Formlabs Inc., the second flexible material may be a biocompatible photopolymer with higher flexibility and elasticity, such as IBT Flex, BioMed Elastic 50A, or BioMed Flex 80A from Formlabs Inc. After the modules and tray body are 3D printed, they can be assembled into the IDB tray.

[0066] According to various embodiments of the present invention, the first flexible material and the second flexible material are selected to create a functional mechanical differential. In one exemplary embodiment, the first flexible material is a resin having a Shore D hardness ranging from 40D to 90D, while the second flexible material is a resin having a Shore A hardness ranging from 30A to 90A. In this configuration, the first flexible material ensures that the tray body accurately snaps onto the patient's dentition, while the second flexible material allows the modules to securely hold the brackets and undergo elastic deformation for peeling and release. In another exemplary embodiment, the first flexible material is a high-modulus photopolymer providing overall structural support and generating a controlled cantilever beam deflection effect when under a load, and the second flexible material is a silicone-like resin configured to securely hold the brackets and undergo elastic deformation for peeling and release. In yet another exemplary embodiment suitable for fused deposition modeling (FDM) or inkjet-based 3D printing, the first flexible material may be the biocompatible MED610 from Stratasys Inc., while the second flexible material may be the biocompatible MED625FLX from Stratasys Inc. This hardness differential between the firstAttorney Docket No.: 47327.0006 PCTand second flexible materials achieves a functional partitioning where the tray body remains dimensionally stable while the modules remain locally flexible.

[0067] As used herein, Shore A hardness and Shore D hardness are standardized measures of material hardness defined under ASTM D2240, and are selected based on different material stiffness ranges. Shore A hardness is generally used to characterize softer, elastomeric materials capable of elastic deformation under relatively low applied forces, such as rubber-like or silicone-like materials. In contrast, Shore D hardness is generally used to characterize more rigid, higher-tensile-modulus materials that exhibit greater resistance to indentation and provide enhanced structural rigidity and dimensional stability. Accordingly, a material having a Shore D hardness value is substantially more rigid than a material having a Shore A hardness value, even when numerical values appear similar. The use of Shore A and Shore D hardness scales in the present invention allows differentiation between materials configured for elastic deformation and materials configured for structural support.

[0068] In the first embodiment, the modules and the tray body are in one flexible material. As shown in FIGS. IB, 2, and 4A to 4B, in this embodiment, each module 12 is configured to receive and hold a bracket 20, wherein each module 12 comprises a receiving well 13, at least one detent 14, a plurality of support surfaces 15, and a plurality of slits 16. The receiving well 13 has four sidewalls 131, wherein the sidewalls 131 are configured to leave a clearance 132 surrounding a bracket pad 22 of the bracket 20 when the bracket 20 is received in the receiving well 13. The at least one detent 14 is formed on the sidewalls 131 of the receiving well 13. Specifically, the at least one detent 14 in this embodiment is four and disposed on each of four sidewalls 131 of the receiving well 13. Each support surface 15 is disposed along an opening or the bottom end of the receiving well 13. Specifically, each support surface 15 in this embodiment comprises a first support surface 151 located at a bottom end of the receiving well 13 and a second support surface 152 located along a rim of the receiving well 13 opening. In a preferred example of the present invention, the plurality ofAttorney Docket No.: 47327.0006 PCTslits 16 are formed on the sidewalls of the receiving well 13 as non-penetrating slits that do not extend through the thickness of the modules 12, and each slit 16 may extend from a rim of the opening of the receiving well 13 toward a bottom portion thereof. The number and arrangement of the slits 16 are not limited to a particular configuration. In certain embodiments, the plurality of slits 16 may comprise two slits respectively formed on two opposite sidewalls of the receiving well 13 in a vertically or horizontally symmetrical manner. In other embodiments, the plurality of slits 16 may comprise four slits, with each of the four sidewalls of the receiving well 13 having one slit formed thereon in a vertically and horizontally symmetrical manner. While two slits 16 are sufficient to provide elastic deformation to facilitate the insertion and release of the bracket 20 while ensuring the overall structural integrity of the module 12 and its retention force on the bracket 20, four symmetrically arranged slits 16 may further improve force distribution and structural stability of the modules 12. Such a symmetrical configuration configured in the modules 12 generates uniform elastic deformation when subjected to an insertion force or a peeling force, thereby stably holding or releasing the bracket 20.

[0069] The bracket 20 as used herein is a conventional orthodontic component well known to those skilled in the art. Another category of brackets is custom-made appliances with customized structural components — including but not limited to their tie wings, slot, and the bracket pad — based on specific clinical requirements and patient-specific data. Regardless of any variations in shape or structure, the bracket 20 is characterized by its suitability for orthodontic applications and its ability to be bonded to a tooth surface. As the specific geometry and dimensions of the bracket 20 are primarily constructed to be compatible with and received by the receiving well 13 of the present invention, the shape and structure of the bracket 20 itself do not constitute a limitation of the present invention. For example, the bracket 20 typically comprises a slot, a plurality of tie wings 21, and a bracket pad 22, most commonly configured as four tie wings 21. As illustrated, the bracket 20 positioned at theAttorney Docket No.: 47327.0006 PCTterminal molar may be a single-wing molar bracket (as shown in FIGS. 1 A, IB, and 7A) specifically configured for the bonding requirements of larger molar surfaces. The slot is a transverse channel specifically dimensioned to receive an archwire, serving as the primary interface for transferring corrective forces from the arch wire to the tooth. The tie wings 21 are usually four, extend from the bracket 20, and are configured to facilitate ligation, allowing ligatures (such as elastic O-rings or stainless steel ties) to be secured around them to hold the archwire firmly within the slot. These tie wings 21 also provide the necessary anchors for the power chain to close the gaps between teeth. Furthermore, the bracket pad 22 serves as the bonding base, featuring a contoured surface that is anatomically adapted to fit the curvature of a specific tooth surface. The bracket pad 22 often incorporates a mesh or micro-etched pattern to enhance mechanical interlocking with a bonding adhesive, thereby ensuring a stable and durable attachment to the dentition. In an exemplary example, there may be one or more retentive features on the pad for improving the stability and durability of brackets, spacers, or other orthodontic appliances. The shapes of one or more retentive features include, but are not limited to, differently shaped protrusions or intrusions, grooves, dimples, sunken, or other tiny structures that provide an extra surface area, bonding strength, or increased interlock between the pad and tooth surface after bonding.

[0070] Besides, the conventional brackets 20, as known in the orthodontic field, may comprise a hook that extends from the body of each bracket for the attachment of elastics or other traction components. In practice, the brackets 20 equipped with hooks are typically disposed on the upper and lower canines, premolars, and molars, rather than on the incisors. As mentioned in the present invention, to ensure each bracket 20 is securely seated within the receiving well 13, the receiving well 13 may further comprise a hook accommodation groove for preventing mechanical interference between the hook and the well structure during the positioning process, thereby ensuring precise adaptation between the bracket base and the tooth surface.Attorney Docket No.: 47327.0006 PCT

[0071] With reference to FIGS. 4A to 6, when the bracket 20 is inserted into the receiving well 13 of each module 12, the bracket 20 is guided into the receiving well 13 from an open side thereof such that the tie wings 21 of the bracket 20 are oriented toward corresponding sidewalls 131 of the receiving well 13. As the bracket 20 is moved into the receiving well 13, the tie wings 21 initially come into contact with one or more detents 14 formed on the sidewalls 131 of the receiving well 13. The detents 14 are positioned along the insertion path of the bracket 20 and are configured to provide a temporary interference with the tie wings 21 during insertion. Upon application of an insertion force, the tie wings 21 are urged past the detents 14. During this process, at least a portion of the sidewalls 131 of the receiving well 13 may elastically deform, for example by flexing outwardly, thereby allowing each tie wing 21 to pass over each detent 14. Such elastic deformation may be facilitated by one or more slits 16 formed along the sidewalls 131 of the receiving well 13, which locally reduce the stiffness of the sidewalls 131 and permit controlled deflection without permanent deformation. After each tie wing 21 passes beyond each detent 14, the sidewalls 131 of the receiving well 13 return toward their original positions due to material resilience. In this seated position, each tie wing 21 is positioned between each detent 14 and the support surfaces 15 disposed along the opening of the receiving well 13. More specifically, once fully received, the tie wings 21 are urged into abutting engagement with the first support surface 151 and the shoulder of the pad 22 abutting against the second support surface 152 of the module 12. The first support surface 151 is disposed at the bottom of the receiving well 13 to support the bracket from its inner side, while the second support surface 152 is disposed along the rim of the opening of the receiving well 13. The first support surface 151 and the second support surface 152 cooperatively define a seating region that constrains the bracket 20 in at least the mesial-distal and occlusal-gingival directions. In this engaged configuration, the tie wings 21 are restrained by the detents 14 in a direction opposing removal of the bracket 20 from the receiving well 13, while simultaneously being supported by the first support surfaceAttorney Docket No.: 47327.0006 PCT151; and the shoulder of the pad 22 supported by the second support surface 152 to retain the bracket 20 relatively to the receiving well 13 in six degrees of freedom. As used herein, the term "six degrees of freedom" refers to the total set of possible movements of the bracket 20 in a three-dimensional space, including translation along three perpendicular axes (mesial-distal, occlusal-gingival, and buccal-lingual) and rotation about said three axes (tip, torque, and rotation). Accordingly, the bracket 20 is securely retained within the receiving well 13, with the tie wings 21 being captured between the detents 14 and the support surface 15, while allowing the clearance 132 around the bracket pad 22 as previously described. This configuration permits reliable positioning and retention of the bracket 20 during indirect bonding procedures, while enabling insertion and removal of the bracket 20 through elastic deformation of each module 12 without damage to the bracket 20 or the tray body 11.

[0072] As will be described in further detail herein, the bracket 20 is retained by the sidewalls 131 of the receiving well 13 on four sides of its body. The space of the receiving well 13 is constituted by the first support surface 151 at the end of the receiving well 13, the sidewalls 131, the detents 14 around the sidewalls 131, and the second support surface 152 at the rim of the receiving well 13 near the opening. When the brackets 20 are assembled into the indirect bonding tray 10 of the present invention, each bracket 20 is pushed into its corresponding receiving well 13. In FIG. 5, the tie wings 21 of the bracket 20 must overcome the detents 14 when inserted into the receiving well 13. The material of the receiving well 13 will be flexible. The detents 14, which are shaped to have a tight fit in the undercut of the tie wing 21, will deform under the insertion force and spring back and settle into the undercuts of the tie wings 21. While the tie wings 21 of the bracket 20 must overcome the detents 14 around the sidewalls 131 of the receiving well 13, the insertion motion will not stop until the bracket pad 22 reaches the second support 152 along the rim of the receiving well 13 and the bracket 20 contacts the first support surface 151 at the end of the receiving well 13. The section view from the distal direction of the bracket 20 held by the detent 14 and confined byAttorney Docket No.: 47327.0006 PCTthe support surface 15 is shown in FIG. 5, and the section view from a gingival direction in FIG. 6. From these two views, it can be seen that the first support surface 151 at the end and the second support surface 152 at the rim of the receiving well 13 are intended to serve as tactile feedback to the user that the insertion is complete, and the detents 14 as the retentive features preventing the bracket 20 from dislodging from the receiving well 13. The receiving well 13 will provide a snug fit on the bracket 20, except for the bracket pad 22, which has no contact with the IDB tray, as shown by the clearance of 132. The built-in snug fit in the receiving well 13 provides sufficient gripping force on the bracket 20 and prevents it from moving relative to the receiving well 13 when the indirect bonding tray 10 of the present invention is engaged onto the dentition and the bracket 20 is pressed toward the tooth surface.

[0073] In addition, as shown in FIG. 2, each module 12 has the receiving well 13 to receive the bracket 20, but the sidewalls 131 of the receiving well 13 do not contact the sidewalls of the bracket pad 22. As previously described, the clearance 132 refers to an intentionally provided space between a receiving well 13 of the module 12 and the bracket pad 22 when the bracket 20 is received, such that the components are not in direct contact. The clearance 132 may provide an accessible pathway for a dental tool to remove excess adhesive (flash) and allow for unimpeded light penetration during a curing process. In addition, the clearance 132 is also provided to accommodate manufacturing tolerances, adhesive material, light transmission, or relative movement during use, and may not necessarily be visible in all views or configurations.

[0074] If the receiving well 13 in each 3D printed module 12 is partially or completely covering the sidewalls of bracket pads 22 as is in the prior art, even though the material of the tray can transmit the UV light to some extent, it will still influence negatively the exposure of the adhesive to the curing light as long as the transmittance is less than 100%. In the present invention, the indirect bonding tray 10 has a lingual part 121 with the inner surfaces to interface with the occlusal and lingual surfaces of the teeth. While the module 12Attorney Docket No.: 47327.0006 PCTmay contact the occlusal surface of the teeth for seating support, it is configured to cover neither the bracket pad 22 nor the surrounding buccal surface of the teeth, thus ensuring that curing light is not blocked from reaching the adhesive. In other words, each module 12 that holds the bracket 20 doesn’t contact the buccal surface of the teeth, leaving the space / clearance 132 around the bracket pad 22. As the indirect bonding tray 10 of the present invention is engaged on teeth with adhesive applied to the bracket pads 22, some adhesive will be pressed out around the rim of the bracket pad 22, and if not removed before curing, will result in flash around the pad. The clearance 132 around the bracket pad 22 also allows the flash to be cleaned by using a dental scaler, Q-tip-like swab, or similar tools before light curing, which reduces the mass of adhesive to be cured, thus increasing the curing efficiency.

[0075] Moreover, bonding failure is also related to the pressure among the bracket pad 22, the adhesive, and the tooth surface. If the pressure is low or lacking, the bonding strength of the adhesive may be undermined. The bracket 20 might debond from the dentition. In the case of direct bonding, the doctor pushes the bracket 20 against the tooth surface while curing the adhesive. This push is controlled by the doctor and generates the proper pressure at the tooth surface where the bracket 20 should be bonded. When the bracket pad 22 is pressed toward the tooth surface by the indirect bonding tray 10 of the present invention, the direction of the reaction force is transmitted in the following sequence: from the bracket pad 22 to the bracket body, and then to the second support surface 152, the detents 14, and the first support surface 151 at the bottom end of the receiving well 13. The reaction force from the tooth surface will cause the module 12 to deflect as a cantilever beam toward the buccal direction.

[0076] As used herein, the term "cantilever beam deflection" refers to the mechanical behavior of the module 12 segments or the sidewalls 131 of the receiving well 13.

[0077] To control the pressure between the bracket pad 22 and the tooth surface, the module 12 that holds the bracket 20 in the indirect bonding tray 10 of the present inventionAttorney Docket No.: 47327.0006 PCTshould press on the bracket 20 towards the bonding location on the tooth surface. The amount of the pressing force and the pressure can be controlled by the interference between the bracket pad 20 and the tooth surface, which is controllable by a gap 23 between the module 12 and the tooth surface. And the module 12 that contains the bracket 20 acts as the cantilever beam under the load of the reaction force from the tooth, as shown in FIG. 3. Assuming the thickness of the bracket pad 22 and adhesive is given, when the gap 23 is normal, the bracket pad 22 with an adhesive layer is just touching the tooth surface and the pressure is minimal. When the gap 23 is reduced, the bracket pad 22 with the adhesive layer interferes with the tooth surface, which deflects the module 12 toward the buccal direction and generates pressure between the bracket pad 22 and the tooth surface. In general, the acceptable error of the bracket 20 bonding is less than or equal to 0.5 mm in distance and less than or equal to 2 degrees in orientation. Too much deflection on the module 12 can throw off the position of the bracket 20. It is reasonable to say that with the indirect bonding tray 10 of the present invention printed in the material with a certain rigidity and the gap 23 controlled for that material, the right amount of pressure can be obtained without too much deflection on the module 12 by finite element analysis and experiments. Other dimensional or geometric measures can be used to control the pressure, though they are highly correlated to the gap 23.

[0078] As shown in FIGS. 4A and 4B, by providing one or more slits 16 in the module 12 formed of the second material (flexible material), the segments of the sidewall 131 function as cantilever beams, where the base connected to the tray body 11 serves as a fixed end, and the portion near the opening serves as a free end. When an insertion force is applied on the bracket 20, — transferring a deflecting force onto the sidewalls 131 of the receiving well 13 — the second material allows the free end to undergo a controlled angular displacement (deflection). This deflection creates a restorative elastic force that provides stable retention of the bracket 20, which cannot be achieved by a rigid, non-slit structure. In other words, the slits 16 built in the receiving well 13 ensure that the sidewalls 131 of theAttorney Docket No.: 47327.0006 PCTreceiving well 13 are easier to deflect for the bracket 20 to be inserted before bonding. They also make each module 12 easier to separate from the bracket 20 after bonding, when the peeling force is applied on the modules 12. The slits 16 don’t have to be through the sidewalls of each module 12. The dimensions of the slits 16, such as. length, width, and depth can be designed for different material properties. By varying the slits 16 dimensions, the retention and insertion force of the receiving well 13 on the bracket 20 can be adjusted.

[0079] Referring to FIGS. 1A, 3, 7A to 11, the second embodiment is a variation of the first embodiment, while maintaining the same core technical concept of the present invention, wherein the tray body 11 of the IDB segment comprises a lingual part 111, and the modules 12 that contain features to hold and position the bracket on the buccal surface of the tooth and features to comprise a buccal part 121. The lingual part 111 of the tray body 11 contains features to engage the occlusal surface and lingual surface of the tooth, and the buccal part 121 may or may not contain features to detachably engage the occlusal surface of the tooth. The tray body 11 and the modules 12 in the second embodiment can be 3D printed with different rigidity. Specifically, the buccal part 121 of the module 12 is formed of a second flexible material having a second rigidity lower than the first rigidity of the lingual part 111 of the tray body 11 formed of a first flexible material. Preferably, the material of the buccal part 121 is softer than that of the lingual part 111 ; the two parts can be detachably assembled. Alternatively, using FDM or inkjet printing technology, the two parts can be 3D printed in one process in two materials with different durometers.

[0080] Referring to FIGS. 1A, 3, 7A to 11, the lingual part 111 is disposed at the bottom of the tray body 11 and includes at least one stud 112 extending toward the buccal side. Each stud 112 is configured as a cylindrical body having a head portion 113 with a radius larger than that of the stud’s shaft. The buccal part 121 of the module 12 comprises at least one locating hole 122 formed through the buccal part 121. Specifically, each buccal part 121 comprises a coupling provided with each locating hole 122, and a mounting comprisingAttorney Docket No.: 47327.0006 PCTthe receiving well 13, detents 14, supports 15, and slits 16 for holding and receiving the bracket 20 as abovementioned. The locating hole 122 is disposed adjacent to or integral with the receiving well 13. As shown in FIGS. 7A to 8, the buccal part 121 and the lingual part 111 are illustrated in an engaged state, in which the locating hole 122 receives the corresponding stud 112 to retain the two parts together. As shown in FIG. 9, the buccal part 121 and the lingual part 111 are illustrated in a disengaged state, in which the buccal part 121 is separated from the lingual part 111, and the stud 112 of the lingual part 111 is not engaged with the locating holes 122 of the buccal part 121. In a preferred example, the lingual part 111 and the buccal part 121 can be connected via at least one strip if fabricated by one 3D printing process, or marked by information for pairing them if fabricated by separate 3D printing processes. It should be noted that the at least one strip disposed between the lingual part 111 and the buccal part 121 is an optional component for matching and pairing the buccal part 121 and lingual part 122 correctly; the lingual part 111 can also be directly and detachably aligned and engaged with the locating hole 122 of the buccal part 121 through the stud 112 of the lingual part 111.

[0081] In another preferred example, as shown in FIGS. 7A to 9, the lingual part 111 further comprises at least one support 114 disposed between two adjacent studs 112; the buccal part 121 further comprises at least one support 123 disposed between two adjacent locating holes 122. More specifically, the segment from UR2 to UL2, as shown in FIG.9, the lingual part 111 includes four studs 112 and three supports 172, while the buccal part 121 includes four locating holes 122 and three supports 123.

[0082] In a more preferred example, as shown in FIG. 10, the head portion 113 of the stud 112 has a radius larger than that of the shaft of the stud 112. As shown in FIG. 11, the locating hole 122 is configured with two distinct internal radii, where radius rl is larger than radius r2. Specifically, radius rl is substantially equal to the radius of the head portion 113, and radius r2 is substantially equal to the radius of the shaft of the stud 112. As illustrated inAttorney Docket No.: 47327.0006 PCTFIGS. 7A to 9, when the lingual part 111 is detachably connected to the buccal part 121, the locating hole 122 is squeezed when the head portion 113 passes through. As shown in FIG.8, at the engaged state, the head portion 113 passes through the small radius r2 of the paired locating hole 122, the shaft of the stud 112 is engaged in the small radius r2 of the locating hole 122, and the head portion 113 locks the shaft and is seated within the large radius rl of the locating hole 122. Simultaneously, the support 114 of the lingual part 111 abuts against the support 123 of the buccal part 121 and are mated in pairs, thereby ensuring a stable snap-fit engagement between the lingual part 111 and the buccal part 121. Alternatively, the stud 112 (as the male part) can be in the buccal part 121, and the locating hole 122 (as the female part) can be in the lingual part 111 on the module 12 or vice versa. In this embodiment, the mated supports 114, 123, and engaged studs 112 through the locating hole 122 j oin the lingual part 111 and the buccal part 121 together stably. As far as the module 12 is concerned, it will still act as a cantilever beam under the reactive force from the tooth surface.

[0083] In this embodiment, the locating hole 122 is circular, and the stud 112 is a corresponding cylindrical body. However, the shape of the stud 112 may include, but is not limited to, a cylinder, an elliptical cylinder, a cube, a rectangular prism, or a triangular prism; the shape of the locating hole 122 may correspondingly include, but is not limited to, a circle, an ellipse, a square, a rectangle, or a triangle. In any case, the shape and structure of the stud 112 and the locating hole 122 are complementary to each other.

[0084] This embodiment can make the insertion of brackets 20 into the receiving well 13 easier due to the buccal part 121 can be pivoted or moved relative to the lingual part 111 to facilitate the insertion of the bracket 20 into the receiving well 13. It is said, the operator can lay the buccal part 121 flat on a working surface and insert the bracket 20 into the receiving well 13, without the lingual part 111 of the IDB tray in the line of insertion, as seen in many IDB designs of prior art with the buccal part 121 and lingual part 111 printed in one body. After all the brackets 20 in one segment of the tray are assembled, the operator flips over theAttorney Docket No.: 47327.0006 PCTbuccal part 121 to engage the locating hole 122 onto the corresponding stud 112 on the lingual part 111 by pushing the module 12 until the head portion 113 goes through the small radius r2 portion of the locating hole 122 and snap into the larger radius rl portion, as shown in FIGS. 10 and 11.

[0085] The third embodiment is also a variation of the first and the second embodiment, while maintaining the same core technical concept of the present invention. In this third embodiment, as shown in FIGS. 12 to 17, each module 12 in this embodiment further comprises a clip 124, and the tray body 11 further comprises a plurality of positioning holes 115, each configured as a through- hole extending through the tray body 11 near the buccal side. To facilitate assembly and functionality, each clip 124 is formed of a material characterized by higher flexibility or lower rigidity relative to the material of the tray body 11. For instance, the clip 124 may be formed of the aforementioned second flexible material, while the tray body 11 is formed of the first flexible material, such that the second rigidity of the clip 124 is lower than the first rigidity of the tray body 11. As aforementioned, the first rigidity may correspond to a Shore D hardness ranging from 40D to 90D, while the second rigidity corresponds to a Shore A hardness ranging from 30A to 90A. The clip 124 is configured to detachably engage the positioning hole 115. Specifically, one side of the clip 124 (toward the buccal direction) is provided with a positioning post 125. The positioning post 125 is a protrusion extending from a side opposite to the receiving well 13, and its shape, size, and dimensions are configured to correspond to the positioning hole 115 of the tray body 11. As illustrated in FIGS. 12, 15, and 16, the positioning post 125 is exemplarily shown as a triangular protrusion, and the positioning hole 115 is a corresponding triangular hole, allowing the positioning post 125 and the positioning hole 115 to be detachably and securely engaged. It should be understood that the shape of the positioning post 125 may include, but is not limited to, a cylindrical, elliptical, cubic, rectangular, or triangular prism shape.Similarly, the shape of the positioning hole 125 may include, but is not limited to, a circle, anAttorney Docket No.: 47327.0006 PCTellipse, a square, a rectangle, or a triangle. Regardless of the specific geometry, the shapes and structures of the positioning post 115 and the positioning hole 125 are complementary to each other to ensure proper alignment. Another side of the clip 124 (toward the lingual direction) comprises the aforementioned receiving well 13, detents 14, supports 15, and slits 16, which are configured for holding and receiving the bracket 20 in a manner consistent with the previously described embodiments (as shown in FIGS. 13 and 14). Specifically, the clip 124 is developed in such a form that it has the receiving well 13 with the same structure as the receiving well 13 as in other embodiments. The features described above of the bonding system, such as the clearance 132 around the bracket pad 22, controllable pressure on the tooth surface, slits 16 in the sidewalls 131 of the receiving well 13, and the holding mechanism surrounding the bracket body, remain the same. FIG. 17 shows the detent 14, and support surfaces 15 of the receiving well 13 mating with the bracket body, the same as those in FIG. 5.

[0086] When each clip 124 is assembled into the indirect bonding tray 10 through the detachably engaged relationship between the positioning post 115 and the positioning hole 125 in this embodiment, a good balance of rigidity and flexibility can be achieved. A biocompatible adhesive may or may not be used to secure the clip 14 to the tray body 11. Alternatively, using FDM or inkjet printing technology, the clip 124 and tray body 11 can be 3D printed in one process in two materials with different durometers. With the dual materials approach, the flexible clip 124 can make the insertion of the brackets 20 and the removal of the tray body 11 from teeth after bonding easy; the tray body 11 of relatively rigid material, with higher dimensional precision, can grip the dentition more firmly and generate sufficient pressure between the bracket 20 and the tooth surface.

[0087] Because the IDB tray, except for the clips 124, is 3D printed in the aforementioned first flexible material, the gap 23 between the module 12 and the tooth surface can be relatively small to obtain a positive pressing force enough for bonding, in a similarAttorney Docket No.: 47327.0006 PCTway described in the first embodiment as shown in FIG. 3. Together with good dimensional precision and stability of the first flexible material portion of the IDB tray, the cantilever effect causes a smaller positioning error; the clips 124 in the aforementioned second flexible material still provide the adaptation and ease in insertion and removal. Balanced benefits of more flexible and more rigid materials can be achieved.

[0088] Referring to the application of the present invention, a method for using the indirect bonding tray 10 of the present invention is described. During an assembly stage, a user inserts the at least one bracket 20 into the corresponding module 12. As an insertion force is applied, the tie wings 21 of the bracket 20 are urged past the detents 14, while at the same time deflecting the sidewalls 131 facilitated by the slits 16, until the bracket body abuts the first support surface 151 and the second support surface 152. This contact provides the distinct tactile feedback, indicating that the bracket 20 is in a fully seated position. Once assembled, adhesive is applied to the bracket pads 22. Notably, the clearance 132 surrounding the bracket pad 22 allows the user to butter the adhesive into the bonding features in the pad 22 without smearing on the module 12 or tray body 11. The clearance 132 surrounding the bracket pad 22 also allows the user to utilize a tool to clean any adhesive flash squeezed out from the rim of the pad before curing, ensuring a clean bonding interface.

[0089] When a segment of the indirect bonding tray 10 of the present invention is positioned onto a patient’s dentition, each module 12 is aligned with a corresponding tooth. By controlling the gap 23 between the modules 12 and the tooth surface, a controlled pressure is generated against the bracket pad 22. This pressure is further optimized by the cantilever beam deflection of the modules 12 under load, which enhances bonding strength. During the curing step, the light source can effectively reach the adhesive through the clearance 132. Finally, to remove the indirect bonding tray 10, a peeling force is applied. The slits 16 in each module 12 allow the sidewalls 131 to elastically deform, facilitating a smooth release of the bracket 20 from the tray while it remains securely bonded to the tooth.Attorney Docket No.: 47327.0006 PCT

[0090] The present invention further provides a method for bonding orthodontic brackets using the aforementioned indirect bonding tray. The method comprises providing an indirect bonding tray according to any of the preceding embodiments. An assembling step is then performed, wherein a bracket is installed into a corresponding receiving well within the tray. During the assembling process, the bracket contacts a first support surface and a second support surface within the receiving well to define a fully seated position of the bracket, thereby providing a user with clear tactile feedback indicating that the bracket is properly seated.

[0091] Subsequently, a positioning step is performed to place the indirect bonding tray, loaded with the bracket, onto a tooth surface. During this positioning step, a controlled interference between the module and the tooth surface causes a deflection of the tray body or the module, thereby generating a controlled cantilever beam effect. This effect produces a controlled pressure between the bracket pad and the tooth surface to enhance bonding strength. Prior to a curing step, a tool may be used to remove excess adhesive flash squeezed out from the rim of the bracket pad through the clearance provided between the tray and the bracket.

[0092] Furthermore, the assembling step may vary according to different embodiments. For instance, in the second embodiment, the assembling step comprises placing a buccal part separately from a lingual part, inserting the bracket into the receiving well of the buccal part, and subsequently engaging the buccal part with the lingual part via a positioning stud. In the third embodiment, the assembling step comprises inserting the bracket into the receiving well of a clip, and subsequently engaging the clip to the tray body detachably.

[0093] As explained previously, all three embodiments have the same features of the clearance around the bracket pad, controllable pressure between the bracket and the tooth surface, holding of the bracket body along its perimeter, and slits in the module.Attorney Docket No.: 47327.0006 PCT

[0094] While particular embodiments of the present invention have been shown and described, it will be obvious to those of ordinary skill in the art that, based upon the teachings herein, changes and modifications may be made without departing from this exemplary embodiment(s) of the present invention and its broader aspects. Therefore, the appended claims are intended to encompass within their scope all such changes and modifications as are within the true spirit and scope of this exemplary embodiment(s) of the present invention.

Claims

Attorney Docket No.: 47327.0006 PCTCLAIMSWhat is claimed is:

1. An indirect bonding tray, comprising:a tray body configured for a customized fit with a plurality of teeth in a patient's dental arch; and,a plurality of modules attached to the tray body, wherein the tray body and the plurality of modules are formed of at least one flexible material, and each module comprises:a receiving well having four sidewalls,at least one detent formed on the sidewalls of the receiving well, a plurality of support surfaces disposed at or along an opening of the receiving well; and,a plurality of slits extending along the sidewalls of the receiving well.

2. The indirect bonding tray of claim 1, wherein the indirect bonding tray is configured as two or three segments.

3. The indirect bonding tray of claim 2, wherein the at least one detent comprises four, and each detent is disposed on a respective one of the four sidewalls of the receiving well.

4. The indirect bonding tray of claim 3, wherein the four detents are formed on an inner surface of the sidewalls of the receiving well.

5. The indirect bonding tray of claim 4, wherein each support surface comprises a first support surface located at the bottom of the receiving well and a second support surface located along the rim of the receiving well opening.

6. The indirect bonding tray of claim 5, wherein the plurality of slits are formed on the sidewalls of the receiving well and configured as non-penetrating slits that do not extend through the thickness of the module.Attorney Docket No.: 47327.0006 PCT7. The indirect bonding tray of claim 6, wherein each slit extends from a rim of the receiving well opening toward a bottom portion of the receiving well.

8. The indirect bonding tray of claim 7, wherein the plurality of slits comprise two slits respectively formed on two opposite sidewalls of the receiving well in a vertically or horizontally symmetrical manner.

9. The indirect bonding tray of claim 7, wherein the plurality of slits comprise four slits, and each of the four sidewalls of the receiving well has one of the four slits formed thereon in a vertically and horizontally symmetrical manner.

10. The indirect bonding tray of claim 7, wherein the tray body and the plurality of modules are formed as a monolithic structure through a single 3D printing process using multiple materials, and the plurality of modules are integrally formed with the tray body.

11. The indirect bonding tray of claim 7, wherein the tray body is formed of a first flexible material having a first rigidity, while each module is formed of a second flexible material having a second rigidity.

12. The indirect bonding tray of claim 11 , wherein the tray body further comprises a lingual part having the first rigidity, and the plurality of modules further comprise a buccal part having the second rigidity, and the lingual part is detachably engaged with the buccal part.

13. The indirect bonding tray of claim 12, wherein the first flexible material and the second flexible material comprise photopolymers, thermoplastics, elastomers, or composites thereof.

14. The indirect bonding tray of claim 13, wherein the first rigidity is a Shore D hardness ranging from 40D to 90D, while the second rigidity is a Shore A hardness ranging from 30A to 90A.

15. The indirect bonding tray of claim 14, wherein one of the lingual part and the buccal part comprises at least one stud extending toward the other of the lingual part and theAttorney Docket No.: 47327.0006 PCTbuccal side; the other of the lingual part and the buccal part comprises at least one locating hole, wherein at least one stud and at least one locating hole are complementary to each other.

16. The indirect bonding tray of claim 15, wherein the shape of the stud comprises a cylinder, an elliptical cylinder, a cube, a rectangular prism, or a triangular prism.

17. The indirect bonding tray of claim 16, wherein the shape of the locating hole comprises a circle, an ellipse, a square, a rectangle, or a triangle.

18. The indirect bonding tray of claim 17, wherein the lingual part and the buccal part each further comprise at least one support, wherein the at least one support of the part comprising the at least one stud is disposed between two adjacent studs, and the at least one support of the part comprising the locating hole is disposed between two adjacent locating holes.

19. The indirect bonding tray of claim 18, wherein the at least one support of the lingual part abuts against the at least one support of the buccal part and is mated with a corresponding support in a paired manner when the lingual part and the buccal part are engaged.

20. The indirect bonding tray of claim 19, wherein at least one stud comprises a head portion with a radius larger than that of the shaft of the stud; at least one locating hole is configured with two distinct internal radii, wherein one radius is substantially equal to the radius of the head portion of the stud, and another radius is substantially equal to the radius of the shaft of the stud.

21. The indirect bonding tray of claim 20, wherein the lingual part and the buccal part are configured to be complementary to each other, such that the lingual part and the buccal part are alignable with each other and detachably engageable in a matching pair relationship.

22. The indirect bonding tray of claim 21 , further comprising at least one strip disposed between the lingual part and the buccal part.Attorney Docket No.: 47327.0006 PCT23. The indirect bonding tray of claim 11 , wherein each module further comprises a clip, and the clip is detachably coupled to the tray body.

24. The indirect bonding tray of claim 23, wherein each clip of the module is formed of the second flexible material having the second rigidity lower than the first rigidity of the first flexible material of the tray body.

25. The indirect bonding tray of claim 24, wherein the tray body further comprises a plurality of positioning holes, each positioning hole is a through-hole near the buccal side and extending through the tray body.

26. The indirect bonding tray of claim 25, wherein one side of the clip comprises the receiving well, at least one detent, a plurality of support surfaces, and a plurality of slits.

27. The indirect bonding tray of claim 26, wherein another side of the clip comprises a positioning post that is a protrusion extending from another side opposite to the receiving well.

28. The indirect bonding tray of claim 27, wherein the shape, size, or dimensions of the positioning post are detachably configured to correspond to the positioning hole.

29. The indirect bonding tray of claim 28, wherein the shape of the positioning post comprises a cylindrical, elliptical, cubic, rectangular, or triangular prism shape.

30. The indirect bonding tray of claim 29, wherein the shape of the positioning hole comprises a circle, an ellipse, a square, a rectangle, or a triangle.

31. An indirect bonding system comprising :an indirect bonding tray as claimed in claim 1 ; and,at least one bracket, each bracket being detachably received in a corresponding receiving well of the module, wherein the sidewalls of the receiving well are configured to leave a clearance surrounding a bracket pad of the bracket when the bracket is received in the receiving well.Attorney Docket No.: 47327.0006 PCT32. The indirect bonding system of claim 31, wherein the at least one bracket comprises a plurality of tie wings, and wherein the at least one detent is configured to elastically deform during insertion of the bracket and spring back to engage with the undercuts of the tie wings to provide the retentive force.

33. The indirect bonding system of claim 32, wherein the receiving well of the indirect bonding tray further comprises a first support surface and a second support surface, and wherein the tie wings of the bracket are configured to abut the first support surface and the second support surface to define a fully seated position of the bracket within the receiving well.

34. The indirect bonding system of claim 33, wherein the first support surface is disposed at a bottom end of the receiving well to limit an insertion depth of the bracket, and the second support surface is disposed along a rim of the receiving well.

35. The indirect bonding system of claim 34, wherein the contact between the bracket and the first and second support surfaces is configured to provide a tactile feedback indicating that the insertion of the bracket is complete.

36. The indirect bonding system of claim 35, wherein the receiving well of the indirect bonding tray is configured to provide a snug fit surrounding a body of the bracket while maintaining the clearance around a bracket pad of the bracket, thereby preventing relative movement between the bracket and the module when the bracket is pressed toward a tooth surface.

37. The indirect bonding system of claim 36, wherein the at least one detent and the first and second support surfaces of the indirect bonding tray collectively constrain the bracket in a predetermined orientation relative to the module.

38. A method for using an indirect bonding tray system as claimed in claim 31, comprising:Attorney Docket No.: 47327.0006 PCTfabricating a tray body and a plurality of modules via 3D printing using at least one flexible material, wherein the tray body and the plurality of modules are formed of the same flexible material or different flexible materials;assembling at least one bracket into a receiving well of each module, wherein the bracket is held by the at least one detent and positioned by a plurality of support surfaces; applying adhesive to at least one bracket pad of the at least one bracket; positioning the tray or the segments of the tray onto a patient’s teeth;curing an adhesive between the at least one bracket pad of the at least one bracket and a tooth surface; and,removing the indirect bonding tray by peeling the tray body away from the teeth, wherein the elasticity of the flexible material of the plurality of modules allow the modules to deform and release the brackets.

39. The method of claim 38, wherein the assembling step further comprises applying an insertion force to urge the tie wings of the bracket past the detents formed on the sidewalls of the receiving well until the bracket abuts the first support surface and the second support surface to define a fully seated position of the bracket within the receiving well.

40. The method of claim 39, wherein the contact between the bracket and the first and second support surfaces provides the tactile feedback to a user indicating that the insertion of the bracket is complete.

41. The method of claim 40, further comprising a step before the curing step, removing adhesive flash squeezed out from a rim of the bracket pad through the clearance using a tool.

42. The method of claim 41, wherein the positioning step further comprises generating a controlled pressure between the bracket pad and a tooth surface by controlling an interference between the plurality of modules and the tooth surface to enhance bonding strength.Attorney Docket No.: 47327.0006 PCT43. The method of claim 42, wherein the controlled pressure is achieved through a cantilever beam effect generated by the deflection of the plurality of modules and / or the tray body when the indirect bonding tray is engaged on teeth.

44. The method of claim 38, wherein the indirect bonding tray is as claimed in claim 12, and the assembling step comprises:placing the buccal part separately from the lingual part;inserting the bracket into the receiving well of the buccal part; and,engaging the buccal part with the lingual part via a positioning stud.

45. The method of claim 38, wherein the indirect bonding tray is as claimed in claim 23, and the assembling step comprises:inserting the bracket into the receiving well of the clip; and,engaging the clip to the tray body detachably.

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