Transfer apparatus for orthodontic appliances and related methods of manufacturing

Abstract

A method of making a transfer apparatus includes providing a physical mockup having a shape that corresponds to a positive shape of a patient's dental arch and one or more orthodontic appliances connected to the arch via one or more coupling arms. A transfer apparatus may be formed over the physical mockup, with the transfer tray representing a negative replica of at least a portion of the mockup. The transfer apparatus may be used to seat the appliance on a patient's dental arch, after which point the appliance can be separated from transfer apparatus and bonded to the associated tooth.

Description

[0001] TRANSFER APPARATUS FOR ORTHODONTIC APPLIANCES AND RELATED METHODS OF MANUFACTURING

[0002] Background

[0003] Orthodontic appliances are used in orthodontic treatments for moving one or more teeth from an initial position (sometimes referred to as malposition or malocclusion) to a desired position in a patient’s dentition. For example, the patient’s teeth may be moved such that their labial sides are aligned with each other to achieve or maximize an aesthetically pleasant appearance of the overall dentition. Further in some cases one or more teeth may be moved to correct a malocclusion. The movement of teeth is typically achieved in traditional orthodontic braces by a pre-biased archwire which is attached via brackets to the teeth, and which applies a force to the teeth toward the desired position over a longer period. The ends of orthodontic archwires are often connected to small appliances known as buccal tubes that are, in turn, secured to the patient’s molar teeth. In many instances, a set of brackets, buccal tubes and an archwire is provided for each of the upper and lower dental arches.

[0004] Orthodontic treatment may also involve the use of alignment trays, such as clear or transparent, polymer-based tooth positioning trays, often referred to as clear tray aligners (CTAs). For example, orthodontic treatment with CTAs may include forming a tray having shells that engage one or more teeth. Each shell may be deformed from an initial position of a tooth, e.g., a malocclusion position. The deformed position of a respective shell of the CTA may apply a force to a respective tooth toward a desired position of the tooth that is an intermediate position between the initial position and a final position resulting from the orthodontic treatment.

[0005] In some examples, small attachments may be bonded to the teeth to improve force application or achieve desired tooth movements. In many types of orthodontic techniques, the precise position of the appliances, be they attachments or brackets, on the teeth is an important factor for helping to ensure that the teeth move to their intended final positions. Proper placement of attachments may ensure proper engagement and interaction of the attachment with one or more CTAs. The design of the attachment may provide a desired physical leverage which creates a desired force on a tooth to produce a specific movement of the tooth during treatment. Attachments are typically constructed of varying materials, shapes and sizes, and can be bonded to the labial or lingual surfaces of teeth in order to interact with CTAs and removable appliances in a variety of different ways. Attachments can be applied to a patient's teeth prior to treatment with aligners. Attachments may also be fabricated prior to attachment to the tooth surface. Attachments may also be substantially assembled at the orthodontic practitioner's office prior to, or in conjunction with, positioning on the patient's tooth (e.g., molded composites, etc.). Generally, bondable orthodontic appliances may be attached to the teeth by a direct bonding procedure or an indirect bonding procedure. In the direct bonding procedure, the appliance is commonly grasped with a pair of tweezers or other hand instmment and placed by the practitioner on the surface of the tooth in its desired location, using a quantity of adhesive to fix the appliance to the tooth. In the indirect bonding procedure, a transfer tray is constructed with wall sections having a shape that matches the configuration of at least part of the patient’s dental arch, and appliances such as orthodontic attachments are releasably connected to the tray at certain, predetermined locations. After an adhesive is applied to the base of each appliance, the tray is placed over the patient’s teeth and remains in place until the adhesive has hardened. The tray is then detached from the teeth as well as from the appliances such that the appliances previously connected to the tray are bonded to the respective teeth at their intended, predetermined locations.

[0006] Indirect bonding techniques offer several advantages over direct bonding techniques. For example, it is possible with indirect bonding techniques to bond a plurality of appliances to a patient’s dental arch simultaneously, thereby avoiding the need to bond each appliance in individual fashion. Additionally, or alternatively, the transfer tray may improve accuracy of attachment placement. The increased placement accuracy of the appliances that is often afforded by indirect bonding procedures helps ensure that the patient’s teeth are moved to their proper, intended positions at the conclusion of treatment. Due to their small size and shape, attachments may be difficult to manipulate for placement in a transfer tray.

[0007] Summary of the Invention

[0008] Prior methods of bonding attachments to teeth commonly relied on either the placement of preformed attachments in an indirect bonding tray or the creation of an attachment directly on the tooth surface. Both methods introduced various errors in the bonding process, appliance fidelity, and treatment effectiveness. Attachments are typically difficult to handle when preformed given their relatively small dimensions, leading to difficulties placing in a tray or directly on teeth. Failures to properly place lead to misdirected forces and suboptimal engagement with the associated CTA. Attempts to create transfer apparatuses along with attachments result in difficult geometries for additive manufacturing and challenges of excess customization that can slow commercial operations. Forming an appliance on the surface of the tooth is fraught with its own challenges, typically centered on the difficulty of ensuring an adequate bond to the tooth surface and sufficient material strength in the formed attachment body. The present inventor sought to solve these and other problems by providing a preformed appliance that could be delivered in a distinct transfer apparatus. In a first aspect, the present disclosure provides a physical mockup for creating a transfer apparatus. The mockup includes a representation of at least a portion of a dental arch of a patient, the dental arch including a bonding tooth, and an appliance arranged on or near a surface of the bonding tooth. The bonding tooth includes a well extending a depth into the tooth volume, and a locator body received in the well. The appliance is frangibly connected to the locator body.

[0009] In another aspect the present disclosure provides a method for creating a transfer tray for one or more orthodontic appliances. The method includes the steps of providing a physical mockup for creating a transfer apparatus, with the mockup comprising a representation of at least a portion of a dental arch of a patient, the dental arch including a bonding tooth. The bonding tooth includes a well extending a depth into the bonding tooth volume. The method further includes the steps of providing a locator body frangibly connected to an orthodontic appliance via one or more coupling arms; and inserting the locator body into the well such that the orthodontic appliance is arranged on or near the bonding tooth surface. Once the prior steps are complete, the method proceeds to forming a tray over the mockup.

[0010] In another aspect, the present disclosure provides a method of making a physical mockup, the method comprising: acquiring a virtual, 3-dimensional model of a patient’s dentition, the model including a representation of a tooth having a 3 -dimensional volume; determining a bonding location for an orthodontic appliance on an outer surface of the tooth; selecting an area of the tooth adjacent to the bonding location; removing a portion of the tooth volume at the selected area to create a locator body geometry; connecting a surface of the locator body to the appliance via a sprue; and subtracting the locator body from the tooth volume to create a well in the tooth.

[0011] For the purpose of this specification, the term “virtual” refers to a three-dimensional computer representation of an object, preferably based on a mathematical representation of a three- dimensional shape in data form and processable by a computer. Such virtual objects in the form of data including their visualizations (for example wire frames or digital renderings) are widely known in the field of Computer Aided Design (CAD).

[0012] For the purpose of the present specification the term “set of’ refers to a “plurality of’.

[0013] As used herein, “orthodontic appliance” includes orthodontic brackets, orthodontic attachments, buccal tubes, orthodontic bands, buttons, and cleats, in particular orthodontic brackets, orthodontic attachments, and orthodontic anchors.

[0014] As used herein, "hardenable" is descriptive of a material or composition that can be cured (e.g., polymerized or crosslinked) or at least partially solidified, for example, by removing solvent (e.g., by evaporation and / or heating); heating to induce polymerization and / or crosslinking; irradiating to induce polymerization and / or crosslinking; and / or by mixing one or more components to induce polymerization and / or crosslinking. As used herein, "hardened" refers to a material or composition that has been cured (e.g., polymerized or crosslinked) or solidified.

[0015] As used herein as a modifier to a property or attribute, the term “generally”, unless otherwise specifically defined, means that the property or attribute would be readily recognizable by a person of ordinary skill but without requiring absolute precision or a perfect match (e.g., within + / - 20 % for quantifiable properties). The term “substantially”, unless otherwise specifically defined, means to a high degree of approximation (e.g., within + / - 10% for quantifiable properties) but again without requiring absolute precision or a perfect match. Terms such as same, equal, uniform, constant, strictly, and the like, are understood to be within the usual tolerances or measuring error applicable to the particular circumstance rather than requiring absolute precision or a perfect match.

[0016] As used herein, “anterior teeth” includes the central incisors, lateral incisors, canines, and first bicuspids.

[0017] As used herein, “posterior teeth” includes the second bicuspid, the first molar, the second molar, and the third molar (if patient still retains wisdom teeth).

[0018] “Mesial” means in a direction toward the center of the patient’s curved dental arch.

[0019] “Distal” means in a direction away from the center of the patient’s curved dental arch.

[0020] “Occlusal” means in a direction toward the outer tips of the patient’s teeth and is inclusive of “incisal”.

[0021] “Gingival” means in a direction toward the patient’s gums or gingiva.

[0022] “Facial” means in a direction toward the patient’s cheeks or lips.

[0023] “Lingual” means in a direction toward the patient’s tongue.

[0024] The above summary of the present disclosure is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The description that follows more particularly exemplifies illustrative embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples can be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list.

[0025] Brief Description of the Figures

[0026] Fig. 1 is a perspective view of a physical mockup for creating a transfer apparatus according to embodiments of the disclosure;

[0027] Fig. 2 is a perspective view of the physical mockup of Fig. 1, enlarged to depict a portion of the dental arch; Fig. 3A is a perspective view of an orthodontic appliance in the form of an attachment according to embodiments of the disclosure;

[0028] Fig. 3B is a perspective view of another orthodontic appliance in the form of an attachment according to embodiments of the disclosure;

[0029] Fig. 3C is a perspective view of another orthodontic appliance in the form of an attachment according to embodiments of the disclosure;

[0030] Fig. 4 is a perspective view of an appliance assembly suitable for at least the embodiments of Fig. 1;

[0031] Fig. 5 is an enlarged, perspective view of a tooth in a fixture model including a well configured for accepting the appliance assembly of Fig. 4;

[0032] Fig. 6 is a perspective view of another appliance assembly suitable for at least the embodiments of Fig. 1;

[0033] Fig. 7 is an enlarged, perspective view of a tooth in a fixture model including a well configured for accepting the appliance assembly of Fig. 6

[0034] Fig. 8 is a workflow for creating a virtual mockup to aid in the creation of the physical mockup;

[0035] Fig. 9 is a perspective view of a virtual orthodontic appliance in the form of an attachment according to embodiments of the disclosure;

[0036] Fig. 10 is a perspective view of a virtual mockup including appliances placed on the virtual teeth according to embodiments of the disclosure;

[0037] Fig. I la is a perspective view of a set of appliance assemblies according to embodiments of the disclosure;

[0038] Fig. 11b is a perspective view of a virtual mockup of Fig. 10 with appliance assemblies removed to reveal well locations;

[0039] Fig. 12 is a perspective view of transfer tray created from a physical mockup of the present disclosure; and

[0040] Fig. 13 is a cross-sectional view of the transfer tray of Fig. 12.

[0041] While the above-identified figures set forth several embodiments of the disclosure, other embodiments are also contemplated, as noted in the description. In all cases, this disclosure presents the invention by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of the principles of the invention. Detailed Description of the Illustrative Embodiments

[0042] Figs. 1 and 2 show aphysical mockup 10 representing the positive shape of a patient’s dental arch 12 including a plurality of teeth 13 and gingiva 14. The physical mockup 10 may be used for physically shaping a transfer apparatus (not shown in Fig. 1 or 2) for bonding orthodontic appliances at predetermined locations on a patient’s teeth. The transfer apparatus forms a negative replica of at least part of the physical mockup 10. Such a transfer apparatus (see e.g., Fig. 12) may for example be obtained from taking an impression from the physical mockup 10, from overmolding the physical mockup 10 or from any other technique in which the positive physical model 10 is used for, preferably directly, shaping a negative replica.

[0043] The transfer apparatus so created from the mockups of the present disclosure may be used to bond orthodontic appliances at prescribed positions and orientations on a patient’s dental arch. As used herein, "position" refers to the location of the appliance at a particular point on the surface of a tooth and "orientation" is the location of appliance relative to an axis or plane of the mockup or the dental arch. An appliance can have a change in orientation that does not change its position on the surface of the tooth. For example, an appliance can be positioned at a particular point on the surface of a tooth and then can be oriented by rotating it, for example, about an axis perpendicular to the surface of the tooth.

[0044] While the mockups of the present disclosure can be used to create transfer apparatuses for multiple orthodontic appliances (brackets, anchors, buttons, etc.), the appliances 30 depicted in Fig. 1 have the shape and function of orthodontic attachments for CT As. As depicted in greater detail in Figs. 3 A and 3B, the appliance 30 includes an appliance body 31 (“body 31”) that is configured to be bonded to the teeth to improve force application by a CTA to achieve desired tooth movements. Body 31 may have any suitable shape, such as a custom-formed shape that is unique to a particular application, patient, tooth, and / or region of a tooth. Body 31 may be sized such that body 31 is difficult to manipulate, e.g., using a tool such as tweezers. For example, body 31 may have a maximum dimension of 30 millimeters (mm) or less and a minimum dimension of 0.25 mm or greater. For typical orthodontic attachments, the body 31 may have a maximum dimension of 10 mm or less.

[0045] As depicted in Fig. 3 A, 3B, and 3C, the body 31 has a generally rectangular shape and includes opposing long edges 32, 33. The long edges 32, 33 are joined by short edges 34, 35. Any one of edges 32, 33, 34, 35 may be concave, convex, linear, or combinations thereof. The long edges 32, 33 each can optionally include a concave middle section with generally linear sections proximate the short edges 34, 35. The short edges 34, 35 themselves are generally linear, though this is not required. A bonding surface 38 of body 31 may be shaped to correspond to a contour of a portion of a tooth of a patient. In one or more embodiments, the bonding surface 38 of one or more appliances

[0046] 30 can include any suitably shaped surface that is not necessarily customized to fit a particular surface of a tooth, i.e., a “generic” base. The bonding surface 38 may include compound curvature corresponding to the expected or average convex curvature of a particular tooth of the dental arch. Corresponding to the contour of the tooth may improve strength of an adhesive bond between body

[0047] 31 and the tooth, reduce an amount of adhesive required for the bond, or both. For example, the bonding surface 38 can be shaped to bond at the facial axis of the clinical crown ("FACC") of a particular tooth of a particular dental arch. The FACC is defined as the curved line formed by the intersection of the mid-sagittal plane and the facial surface of a given tooth. In some examples, bonding surface 38 may include etched, sandblasted, embossed, or other microstructured patterns intended to facilitate more secure bonding.

[0048] The bonding surface 38 can have a tooth facing surface contour that is customized to fit any suitable surface of a tooth. For example, in one or more embodiments, the bonding surface 38 has a tooth-facing surface contour that is customized to fit a labial surface of a given tooth. Having a customized bonding surface 38 can allow the appliance 30 to be configmed with a lower profile for patient comfort. Any suitable technique or combination of techniques can be utilized to form customized bondable surfaces, e.g., the techniques described in U.S. Patent No. 10,136,965 (Wiechmann, et al.), and U.S. Patent Publication No. 2005 / 0277084 (Cinader, Jr., et al.) and including., for example, the Boolean subtraction of a virtual tooth from a virtual appliance bonding surface in CAD or other software.

[0049] The body 31 may include any suitable shape that is configured to transfer a force from a CTA to the tooth, retain the CTA on the tooth, or both. For example, one or more portions of body 31 may be hemispherical, rectilinear, curvilinear, or irregular in shape. In some examples, any surface of the body 31 may include one or more surface features, including, but not limited to, one or more tapers, undercuts, overhangs, recesses, negative drafts, or other features configured to engage or otherwise interact with a CTA or a transfer tray. As illustrated in Fig. 3B, body 31 may define a beveled buccal / lingual facing surface 39. In some examples, a beveled body 31 may improve release of body 31 from a transfer tray after bonding to a tooth and / or improve transfer of force from a CTA to the tooth by concentrating contact of the CTA with body 31 at the apex of the bevel or provide a lead-in for engagement when there is a mismatch in position between a CTA and tooth.

[0050] The buccal-lingual facing surface 39 may include at least one retention feature to aid in one or more of removing the appliance 30 from the mockup 10 and aiding the arrangement of the appliance in a transfer apparatus. As depicted in Fig. 3C, the retention features may include buccal- lingually extending features and occlusal-gingivally (or mesial-distally, depending on orientation) extending features. For instance, the retention feature 45 can include a stem (not shown in Fig. 3C) projecting out from the facing surface 39 and a cap 48 at the far end of the stem. The cap 48 projects in a substantially orthogonal direction from the end of the stem and includes at least one dimension greater than the stem to create one or more undercuts 49 adjacent the end of the stem. Transfer apparatus material (see Fig. 13) may at least partially fill the area between the undercut(s) 49 and the facing surface 39, which in certain embodiments can aid retention of the appliance in the apparatus and enhance removal of the appliance from mockup 10. The stem and / or cap may be frangible, similar to sprues / coupling arms 50 below, or may remain with appliance 30. The stem 1246 as a whole may be conical, frusto-conical, pyramidal, frusto-pyramidal, or any other appropriate shape. Likewise, the cap 48 may be triangular, rectangular, elliptical, circular, ovular, hemispherical, or any other appropriate shape.

[0051] The appliance 30 includes a long axis 40 (i.e., longitudinal axis), as well as a central axis 42 normal to the long axis 40 and extending through both the bonding surface 38 and the facing surface 39. The axes 40, 42 extend through the approximate center of the appliance, which may be both the mesial-distal and occlusal-gingival center, though the precise identity will depend on appliance 30 orientation on the bonding surface. The long axis 40 extends between the short edges 34, 35. Both of the long axis 40 and central axis 42 can, in certain embodiments, be useful for locating the appliance 30 at the desired position and orientation on the tooth, as well as dictating certain aspects of the physical mockup 10, as further explored below.

[0052] Returning to Figs. 1 and 2, the mockup 10 includes a support body (i.e., mold body) 15 extending below the gingiva 14 to provide stability for improved ease of mockup creation and subsequent transfer apparatus manufacturing. The bottom of the mold body is typically substantially planar, creating a base plane “B”. The mockup further includes a vertical axis “V” that is perpendicular to the occlusal plane of the dental arch, which can be determined using techniques known in the art and further described below. The vertical axis V can be normal to the base plane B in some locations along the arch 12, but this is not typical or necessary.

[0053] In the physical mockup 10 the patient’s teeth 13 are represented in the malocclusion at the beginning of either treatment or a new stage of treatment. The exemplary mockup 10 shown in the drawings is representative of the patient's upper dental arch, although it should be understood the methods and systems of the present disclosure are equally suitable for the patient's lower dental arch. The entire, upper dental arch 12 is depicted in Fig. 1 , while an enlarged portion of the arch is depicted in Fig. 2 for descriptive clarity. Alternatively, the physical mockup may include the entire dental arch (Fig. 1) or a lesser portion thereof (for example, an arch quadrant or a single tooth, not shown) depending on the number of appliances intended to be bonded to the teeth during a given bonding procedure.

[0054] The interior volume of the mockup 10 may be at least partially filled with material. In some embodiments, including those with apertures described below, it can be advantageous for the interior volume of mockup to be at least partially empty, allowing access to areas adjacent the tooth surfaces from the interior. In such embodiments, the interior may include support beams or other scaffolding to support the physical integrity of the mockup during creation of the mockup itself or the transfer apparatus. In other embodiments, the interior volume may be unfilled, leaving the mockup essentially hollow.

[0055] While the mockup 10 as depicted includes representations of all tooth surfaces and adjacent gingiva, other embodiments may feature less fidelity to the patient’s dental arch. For instance, a mockup 10 may include only a positive representation of occlusal and labial surfaces of the teeth, which may be viable for labial bonding of appliances. In such embodiments, the lingual surfaces may be omitted from the arch or may be generic and not representative of the patient’ s tooth surfaces. Typically, but not exclusively, at least the patient’s occlusal surfaces are represented in the mockup to ensure adequate registration of the eventual transfer apparatus with the patient’s actual dental arch. Any surface of the mockup may include indicia identifying the associated tooth, patient, or phase of treatment relevant to the appliance 30. The indicia may include text, symbols, coloring, or the like.

[0056] An orthodontic appliance 30 is fixed adjacent the bonding surface 17 (here labial tooth surface) of several teeth 13. Each appliance 30 includes at least one associated locator body 60 configmed to locate the associated appliance 30 proximate the mockup tooth surface (here labial tooth surface 17) at the prescribed or otherwise intended bonding position and orientation. Each locator body 60 is connected to the associated appliance 30 via one or more coupling arms (i.e., sprues) 50 that project from an outer surface of the locator body in a generally buccal direction. Appliances 30 may be attached to all of the teeth 13 in the dental arch 12 or may be attached to only certain selected teeth as may be desired by the practitioner or otherwise prescribed according to an orthodontic treatment plan. As depicted in Fig. 1, each tooth 13 of the dental arch 12 receives an appliance 30. Each appliance 30 on physical mockup 10 has been correctly positioned on the appliance bonding surface 17 of tooth 13 and oriented such that it can provide the desired force to the teeth of the patient when combined with another dental appliance (e.g., CTA) or appliance component (e.g., archwire or polymer band).

[0057] The mockup 10 of this embodiment and the appliances of other embodiments, unless otherwise indicated, are described herein using a reference frame attached to a labial surface of a tooth on the upper jaw. Consequently, terms such as labial, lingual, mesial, distal, occlusal, and gingival used to describe the mockup 10 and appliance 30 are relative to the chosen reference frame. The embodiments, however, are not limited to the chosen reference frame and descriptive terms, as the appliance 30 may be used on other tooth surfaces and in other orientations within the oral cavity. For example, the mockup 10 may locate appliances proximate to the lingual surface of one or more teeth or locate appliances on both the lingual and labial tooth surfaces. Those of ordinary skill in the art will recognize that the descriptive terms used herein may not directly apply when there is a change in reference frame. Nevertheless, the embodiments are intended to be independent of absolute location and orientation within the oral cavity and the relative terms used to describe embodiments are merely to provide a clear description of the embodiments in the drawings. For the remainder of the application, the appliance bonding surface is inclusive of the labial, lingual, and occlusal (for e.g., bite stops) surfaces, but is depicted as the labial surface.

[0058] As depicted with additional clarity in Fig. 2, each appliance is coupled to a bonding tooth via a single coupling arm 50 and locator body 60. In other suitable instances, the appliances may be connected to the locator body via two or more coupling arms, and / or via two or more locator bodies. The coupling arm 50 (i.e., sprue) is attached on one end to a locator body 60 received in a well 70 (shown in Figs. 5 and 7) that includes geometry and / or mating features to aid in retaining the body 60 within the well 70. The locator body 60, in the depicted embodiment, forms a region of the bonding tooth surface 17 and, save for connection of the sprue 50, has an outer surface contour substantially matching the patient’s actual tooth surface. The locator body 60, well 70, and sprue 50 cooperate to accurately position and orient that appliance 30 on the bonding tooth surface 17, as further described below.

[0059] As depicted in further detail and isolation in Figs. 4 and 6, the locator body 60 includes an outer surface 62, depending side surfaces 63, and abase 64. The locator body 60 as a whole may be conical, frusto-conical, pyramidal, frusto -pyramidal, or any other appropriate shape that limits rotation about a generally buccal-lingual axis and / or other movements within the well. The rotation limiting shape may include one or more facets that alone or in combination inhibit rotation (e.g., a half moon, a clover, etc.). In some embodiments, the body 60 includes a decreasing taper in a cross- sectional dimension between the outer surface 62 and base 64. For example, the body may include one or more side surfaces having a negative draft angle of at least 5 degrees and no greater than 15 degrees, providing one or more canted surfaces. The presence of canted surfaces on can aid in the placement of a locator body within the well 70, and removal of a transfer apparatus from the mockup 10 without removing the locator body 60 from the well 70. In other embodiments, the body 60 has substantially continuous cross-sectional dimensions.

[0060] The shape and cross-sectional dimensions of the locator body may be the same for each bonding tooth, allowing for improved standardization of manufacturing and assembly. In other embodiments, at least one of the shape and the cross-sectional dimensions may be modified, to allow correspondence between a given body and a particular bonding tooth. For instance, a conical body shape may indicate correspondence with a locator body for an anterior tooth, while a frusto- pyramidal assembly indicates correspondence with a posterior tooth. Alternatively or additionally, the surrounding tooth surfaces can include indicia identifying the associate carrier assembly. The indicia may include text, symbols, coloring, scribe lines, or the like. Similarly, any surface of the locator body 60 may include indicia identifying the associated tooth or phase of treatment relevant to the appliance 30. The indicia may include text, symbols, coloring, or the like.

[0061] Turning to Figs. 5 and 7, the well 70 associated with a bonding tooth includes an opening 72 on the bonding surface for receipt of the locator body 60. For the depicted tooth, the well 70 is disposed nearer the occlusal surfaces of the tooth 13 than the appliance 30. A well 70 may also be located at least partially in the gingiva 16 or the mold body 15 of the mockup 10. The well 70, as depicted, is closed on one end and terminates at bottom wall 74 through at least a portion of the tooth volume in the mold body. In other embodiments, a well may feature a recess extending the full width of the mold body from facial surface to lingual surface, with openings on both ends.

[0062] The well 70 is dimensioned to retain the locator body 60 and inhibit rotation (and / or other movements) of the appliance 30, while also aiding in aligning the appliance with tooth surface so that the appliance arrives at the prescribed bonding location. As depicted in, for example, Fig. 5 the well 70 may feature a generally cubic shape in a plane perpendicular to the occlusal plane. The cross-sectional shape (e.g., triangular, rectangular (including square), elliptical, etc.), of the well can be uniform from opening to bottom, or in other implementations the shape may vary. The opening 72 may be triangular, rectangular (including square), circular, ovular, or polygonal. The well 70 as a whole may be cubic, conical, frusto-conical, pyramidal, frusto-pyramidal, or any other appropriate shape. In some embodiments, the well 70 also includes a decreasing taper in a cross-sectional dimension, measured parallel to the opening, as the bottom 74 is approached. In other embodiments, the well 70 has substantially continuous cross-sectional dimensions.

[0063] The orientation, shape, and cross-sectional dimensions of the well 70 may be the same for each locator body 60, allowing for improved standardization of manufacturing and assembly. In other embodiments, at least one of the orientation, shape, and cross-sectional dimensions may be modified to allow correspondence between a given carrier assembly and a particular type of bonding tooth. For instance, a circular shape may indicate correspondence with a locator body for an anterior tooth, while a rectangular indicates correspondence with a locator body for a posterior tooth.

[0064] The inhibition or prohibition of rotation or movement is typically achieved when the opening of the well 70 and the cross-sectional shape of the locator body 60 are similar if not substantially identical. This correspondence is not strictly necessary as, for example, a reversible friction fit between a conical locator body 60 and conical well 70 may nonetheless adequately inhibit rotation / movement of the appliance. Alternatively, the locator body 60 may have a conical shape that nonetheless does not substantially rotate within a rectangular or other polygonal well, with each shape providing a facet to inhibit rotation.

[0065] Either or both of the locator body 60 and well 70 may further include retentive features to mate with corresponding features on the carrier assembly. For instance, the well may include one or more depressions intrusive to a sidewall. The depression can be dimensioned to mate with a bump projecting from a depending side surface of the locator body 60. As should be appreciated, the bump could alternatively be formed within the well, with a corresponding depression on the locator body. The addition of retentive features can aid in securely holding appliance on the tooth, particularly during assembly of multiple appliances on the physical mockup, or handling of the physical mockup in manufacturing after the desired number of appliances are assembled to the mockup.

[0066] The location (i.e., position and orientation) of the well 70 on the mockup is primarily dictated by the intended bonding location and geometry of the appliance 30, which in turn controls the regions of the bonding tooth avaiblable to accomodate a well 70.. Generally, but not exclusively, an appliance 30 oriented on a bonding tooth with a long axis 40 within no greater than 35 degrees rotation from the vertical axis V (or the axis perpendicular to the base plane B) of the mockup 100 results in a well 70 located in a mesial or distal direction from the long edges 32, 33 of the appliance 30. An appliance 30 having a long axis 40 oriented within greater than 35 degrees to 90 degrees rotation from the vertical axis V (or the axis perpendicular to the base plane B) generally result in a well 70 located in an occlusal or gingival direction from the long edges 32, 33 of the appliance. The chosen location of the well 70 relative to the appliance 30 generally has sufficient surface area to create an associated locatorbody, as further detailed below. A sufficient surface area, in this context, is generally larger than the connection point of the coupling arm and suitable for creating sufficient volume of the locator body to withstand creation of the fixture model and subsequent formation of the transfer apparatus.

[0067] In certain embodiments, the well 70 accounts for a relatively small volume within the overall volume of the bonding tooth, as depicted in Fig. 5. Such relatively small wells are typically useful for wells disposed on the facial or lingual surface, and typically account for no greater than 15%, no greater than 10%, or no greater than 5% of the total tooth volume. In other embodiments, as depicted in Fig. 7, the well 70 accounts for a greater portion of the tooth volume, including a majority (i.e., at least 50%) of the incisal or occlusal surfaces 18. Larger wells (and associated locator bodies) may improve the stability of the physical mockup and the fidelity of appliance placement, though may also increase manufacturing resources necessary to build an appliance assembly (e.g., locator body, coupling arm, and appliance).

[0068] It is further contemplated that additional wells may be arranged along one or more edges of the appliance. In some examples, it may be advantageous to use more than two locator bodies / wells for a larger attachment body and / or to increase the robustness of the article during fabrication and handling, thereby preventing premature breakage. Accordingly, two or more wells and associated locator bodies may be incorporated into any of the articles described herein if desired. Additionally or alternatively, a well may be placed such that an associated locatorbody is connected to appliances on adjacent teeth. Such placement is typically, though not exclusively, nearer the gingiva or interproximal surfaces of the teeth.

[0069] The coupling arm 50 can connect the locator body 60 to the appliance body 30, as depicted, or may connect on other regions of the appliance body. The coupling arm 50 is frangible when bending, twisting, compression, or tension forces are applied, such as, for example, to the coupling arm 50 via a tool or removal of the transfer apparatus from the mockup 10. In some examples, a size and / or a shape of coupling arm 50 may be selected to have a sufficient structural integrity to allow handling of mockup 10 while also breaking easily when desired. The coupling arms 50 may be broken by using a tool to bend twist or shear by pushing or pulling. In the same or other implementations, the coupling arm 50 may include stress concentration features such as perforations, notches, scores, or otherwise weakened regions to aid in the separation of the coupling arm 50 from the appliance 30. In the same or other implementations, the coupling arm 50 can be made from a relatively rigid material that can be broken at or near the appliance body 31.

[0070] The cross-sectional shape (e.g., triangular, rectangular, elliptical, circular, ovular, etc.), of the coupling arm can be uniform along a length of the arm, or in other implementations the shape may vary. The coupling arm 50 as a whole may be conical, frusto -conical, pyramidal, frusto- pyramidal, or any other appropriate shape. To aid in the separation, each coupling arm 50 typically has a cross-sectional area between about 0.05 mm2and 0.75mm2, though the size of the area may change based on one or more of appliance body and geometry.

[0071] In some embodiments, one or more of the coupling arms 50 include a decreasing taper in a cross-sectional dimension as the appliance 30 is approached. Force may then be applied to the coupling arm 50 and the thicker portion adjacent the bonding tooth surface can resist the potential for the support to break during the formation of the transfer apparatus. Furthermore, a tapered coupling arm may negate the need for a cutting tool and separation of the appliance 30 from the dental arch 12 may only require the user to apply a compressive or tensile force on the thinner support end to initiate the break. Additionally, when the dental arch 12 and appliance 30 are separated, there may be reduced volume of the coupling arm still attached to the appliance 30. In presently preferred implementations, the coupling arm 50 included a square, elliptical, or circular cross-sectional shape with a decreasing taper.

[0072] In certain presently preferred embodiments, each coupling arm features a plurality of segments. The first segment 51 extends from the connection point at an angle normal to the appliance body 31, with a generally increasing taper, to a pivot region 52. The second segment 53 extends from the pivot region 52 to the locator body 60 in a direction roughly returning towards the tooth surface. A multi-segment coupling arm can aid in the separation of the locator body from the appliance, and ensure that the coupling arm 50 does not contact or interfere with the tooth surface of the mockup or the patient’s mouth. The clearance between the coupling arm 50 and the tooth surfaces can also offer a space to insert a tool to aid in the separation of the appliance 30 from the locator body. The segmented coupling arm(s) can further provide more predictable and desirable separation forces when breaking the attachment from the carrier assembly. The segmented coupling arm(s), featuring a controlled connection deliberately normal to the appliance body, may be used with any embodiments of the present disclosure.

[0073] In some examples, after breaking coupling arms 50, a vestige or a nub may be left on or within the body 31. In some examples, the vestige or nub may be removed using any variety of automated cutting and / or polishing tools. In other examples, the vestige or nub may be removed using pressure and friction generated by operation of a hand tool (e.g., a dental probe). In yet other examples, the vestige or nub may remain if it does not interfere with appliance engagement or patient comfort. In certain embodiments, the vestige or nub, if sufficiently proximate the bonding surface 38, may enhance bonding to the tooth by providing more bonding surface area.

[0074] The above depictions and discussions focus primarily on the bonding of a single appliance to a single tooth surface. It is contemplated that more than one appliance may be bonded to a tooth surface according to the concepts of the present disclosure, and / or that more than one tooth surface serves as a bonding surface. In the latter case, one or more appliances may be bonded, for example, to the lingual and labial surfaces of the requisite tooth. Other combinations and modifications are possible and within the scope of the present disclosure.

[0075] The physical mockup 10 may be manufactured in discrete, integrally formed component parts. The two discrete components are typically a) the arch 12, including the mold body 15 (collectively a fixture model); and b) the locator body and appliance assemblies. In other implementations, for example, the arch may be constructed with apertures for receipt of preformed alignment pins. As another alternative, the arch 12, mold body 15, locator body 60, and coupling arm(s) 50 may be integrally formed as a single piece, with an appliance subsequently fixed relative to the coupling arms and appliance bonding surface. Any component of the physical mockup 10 may be manufactured by additive manufacturing. Accordingly, the position of the appliance 30 relative to the dental arch 12 can be determined by computer aid and manual assembly tolerances can be avoided. Examples of suitable additive manufacturing processes include solid freeform fabrication such as 3D printing processes, stereolithography methods, fused deposition modeling, laminated object manufacturing, laser engineered net shaping, selective laser sintering, shape deposition manufacturing, selective laser melting, and solid ground curing.

[0076] The physical mockup 10, and any or all components thereof, can be made from the full range of 3D printed materials, molded polymeric material or CAD / CAM shaped polymeric materials having certain desired strength, flexibility, translucency, or color. For example, the material can be polymeric material that may be transparent, translucent, or opaque. In some embodiments, clear or substantially transparent polymeric material that may include, for example, one or more of amorphous thermoplastic polymers, semi-crystalline thermoplastic polymers, transparent thermoplastic polymers, and thermoset polymers. Thermoplastics can be chosen from polycarbonate, thermoplastic polymethane, acrylic, polysulfone, polyprolylene, polypropylene / ethylene copolymer, cyclic olefin polymer / copolymer, poly-4-methyl-lpentene or polyester / polycarbonate copolymer, styrenic polymeric materials, polyamide, polymethylpentene, polyetheretherketone and combinations thereof. In another embodiment, the body material may be chosen from clear or substantially transparent semi-crystalline thermoplastic, crystalline thermoplastics and composites, such as polyamide, polyethylene terephthalate, polybutylene terephthalate, polyester / polycarbonate copolymer, polyolefin, cyclic olefin polymer, styrenic copolymer, polyetherimide, polyetheretherketone, polyethersulfone, polytrimethylene terephthalate, and mixtures and combinations thereof. In some embodiments, the body material is a polymeric material chosen from polyethylene terephthalate, polyethylene terephthalate glycol, poly cyclohexylenedimethylene terephthalate glycol, and mixtures and combinations thereof. In additional embodiments thermoset polymers include acrylics, urethanes, esters, silicones, thiolenes, epoxies, olefin metathesis and combinations thereof.

[0077] In certain presently preferred circumstances, the locator body and appliance are integrally formed as a unitary component as part of an additive manufacturing process or injection molding process. The mockup of the present disclosure may be made of metal (such as alloys of stainless steel or other metallic materials), ceramic materials (including monocrystalline and polycrystalline light- transmitting ceramics) and polymeric materials (such as fiber-reinforced polycarbonate). Suitable ceramic materials are described, for example, in US Patent No. 6,648,638 (Castro et al.). Suitable materials for use in additive manufacturing may include, but are not limited to, materials described in International Publication Nos. WO 2020 / 104873 (Chakraborty etal.), WO 2019 / 048963 (Parkar et al.), WO 2018 / 231583 (Herrmann et al.), WO 2016 / 191534 (Mayr et al.), WO 2016 / 191162 (Mayr et al.), and WO 2014 / 078537 (Sun et al.). Other material iterations and combinations are also possible.

[0078] Under presently advantageous circumstances, the locator body, coupling arm, and appliance may be formed from a curable composition primarily featured for creating certain dental crowns. The curable composition includes a resin matrix comprising: polymerizable (meth)acrylate(s) not comprising a urethane moiety, polymerizable urethane(meth)acrylate(s), filler including nanocluster(s), and an initiator system. Such compositions include a viscosity below 150 Pa*s at 23°C and a shear rate of Is'1and do not include a softener in an amount of more than 5 wt.%. The composition, in greater detail, may comprise the polymerizable (meth)acrylate(s) not comprising a urethane moiety in an amount of 40 to 85 wt.%, polymerizable urethane(meth)acrylate(s) in an amount from 1 to 35 wt.%, nanocluster in an amount of 5 to 40 wt.%, fumed silica in an amount of 0.5 to 5 wt.%, photoinitiator in an amount of 0.01 to 3 wt.%, and organic dye in an amount of 0.001 to 0.5 wt.%.

[0079] Such curable compositions can be characterized by a combination of specific properties such as high mechanical strength, high fracture resistance and high aesthetics including stain resistance. The cured article has typically the following properties alone or in combination: 1) flexural strength: 50 to 200 MPa or 80 to 150 MPa determined according to ISO 4049:2009 using a test bar having the dimensions 6*4*25 mm, while 6 mm is the width of the test bar; 2) E-modulus 1,000 to 4,000 MPa determined according DIN EN 843-2:2007 using the flexural strength method, while calculation of the modulus is done in the range of 20% and 50% of maximum force of the samples; and 3) impact strength: 5 to 15 kJ / m2 determined according to DIN 53453: 175-05. Further details regarding these compositions may found in European Patent No. 3638189 (Herrmann et al.). Other suitable compositions for additive manufacturing include, for example, a composition comprising a (meth)acrylate not comprising a urethane moiety, a urethane (meth)acrylate, photo -initiator, additives, discrete filler particles having an average particle size in the range of 10 to 40 nm and having been surface treated with a silane surface treating agent selected from a silane surface treating agent comprising a (meth)acrylate moiety, a silane surface treating agent not comprising a (meth)acrylate moiety, and a mixture of both, the discrete filler particles being present in an amount of 20 wt.% or more, the curable composition not comprising the following components alone or in combination: aggregates of nano-sized particles, agglomerates of nano-sized particles, fumed silica, each in an amount of 2 wt.% or more, wt.% with respect to the whole composition. The cured article has typically the following properties alone or in combination: 1) flexural strength: 50 to 200 MPa, determined according to ISO 4049(2019); 2) E-modulus: 1 to 4 GPa, determined according to DIN EN 843-2:2007. Further details on such compositions may be found, for example, in co-owned application Publication Number No. WO 2024 / 018305 Al entitled “Curable Composition for Producing Orthodontic Attachments”, published on January 24, 2024.

[0080] Commercially available resins suitable for appliances also include those listed below in Table 1:

[0081] Table 1 : Exemplary Suitable Resins for Additively Manufacturing Appliances

[0082] The appliance, locator body, and coupling arms can be formed of the same material or can be formed of different materials through one or more manufacturing processes. For example, a photopolymerizable material used to form a carrier assembly optionally includes a first composition and a second composition and making carrier assembly accordingly includes selectively curing the first composition to form the appliance 30 and selectively curing the second composition to form coupling arms and / or crane body. In some examples, the appliance may be formed of a material that has a higher ultimate strength than a material of which coupling arms are formed.

[0083] In some examples, the methods of the present disclosure may include a three-dimensional (3D) printing step in the creation of the model dental arch 12 (including mold body), the appliance 30, coupling arm(s), the locator body 60, or any combination thereof. Three-dimensional printing may include, for example, forming the article from a plurality of layers of a photopolymerizable material described herein by selectively curing the photopolymerizable material in a layer-by-layer manner. In some examples, additive manufactured article may include a plurality of materials bonded to each other. The layers of the photopolymerizable material can be deposited according to an image of the three-dimensional article in a computer readable format. For example, the photopolymerizable material may be deposited according to preselected computer aided design (CAD) parameters (e.g., a data file). In some examples, the photopolymerizable material is cured using actinic radiation, such as UV radiation, e-beam radiation, visible radiation, or combinations thereof.

[0084] The foregoing techniques can be repeated a selected number of times to provide the 3D article. For example, in some cases, this process can be repeated “n” number of times. Further, it is to be understood that one or more steps of a method described herein, such as a step of selectively applying energy to a layer of photopolymerizable composition, can be carried out according to an image of the 3D article in a computer-readable format. Suitable printers include the VIPER, from 3D Systems, the D30II or D90, available from Rapid Shape, Heimsheim, Germany; and the MOONRAY and MIDAS, available from SprintRay, Los Angeles, California.

[0085] Other techniques for three-dimensional manufacturing may be suitably adapted to the techniques described herein. More generally, three-dimensional fabrication techniques continue to become available and may be adapted to use with photopolymerizable compositions described herein, provided they offer compatible fabrication viscosities and resolutions for the specified article properties, for instance continuous additive manufacturing in which a build plate is (essentially) continuously moved through a vat of photopolymerizable material. In certain examples, an apparatus adapted to be used in a continuous mode may be employed, such as an apparatus commercially available from Carbon 3D, Inc. (Redwood City, CA), for instance as described inU.S. Patent Nos. 9,205,601 and 9,360,757 (both to DeSimone et al.). For example, in any method described above, selective curing of a photopolymerizable material includes continuous photopolymerization of at least one of the first portion of the article or the second portion of the article. Further details of methods for additive manufacturing may be found in International Publication No. 2021 / 130624 (Cinader et al.), entitled Preformed Orthodontic Attachments.

[0086] Designing and Creating the Physical Mockup

[0087] The manufacturing of the physical mockup is typically based on a virtual mockup prepared in a computer system. Such a virtual mockup preferably corresponds to a mathematical representation of a three-dimensional shape which can be processed by a computer, for example by a CAD system. Further the virtual mockup is preferably available in the form of computer data which can be used to control an additive manufacturing machine for manufacturing the physical mockup as defined by the virtual mockup. The virtual mockup may be designed or generated from superimposing or merging a virtual dental arch of a patient with a set of virtual appliances as further described below. The functions or algorithms described herein may be implemented in software in one embodiment. The software may consist of computer executable instructions stored on computer readable media or computer readable storage device such as one or more non-transitory memories or other type of hardware-based storage devices, either local or networked. Further, such functions correspond to modules, which may be software, hardware, firmware or any combination thereof. Multiple functions may be performed in one or more modules as desired, and the embodiments described are merely examples. The software may be executed on a digital signal processor, ASIC, microprocessor, or other type of processor operating on a computer system, such as a personal computer, server or other computer system, turning such computer system into a specifically programmed machine. The term “processor,” as used herein may refer to any of the foregoing structure or any other structure suitable for implementation of the techniques described herein. In addition, in some aspects, the functionality described herein may be provided within dedicated software modules or hardware modules configured for performing the techniques of this disclosure. Even if implemented in software, the techniques may use hardware such as a processor to execute the software, and a memory to store the software. In any such cases, the computers described herein may define a specific machine that is capable of executing the specific functions described herein. Also, the techniques could be fully implemented in one or more circuits or logic elements, which could also be considered a processor.

[0088] Often, computer readable media are provided as part of a computing device. The computing device may have one or more processors, volatile memory (RAM), a device for reading machine- readable media, and input / output devices, such as a display, a keyboard, and a pointing device. Further, a computing device may also include other software, firmware, or combinations thereof, such as an operating system and other application software. A computing device may be, for example, a workstation, a laptop, a tablet, a smart phone, a personal digital assistant (PDA), a server, a mainframe or any other general-purpose or application-specific computing device. A computing device may read executable software instructions from a computer-readable medium (such as a hard drive, a CD-ROM, or a computer memory), or may receive instructions from another source logically connected to computer, such as another networked computer. Data can be communicated directly to an application, e.g., on a mobile device and / or directly to a cloud platform system via cellular connection, a Wi-Fi router or a hub.

[0089] In general, and as depicted in Fig. 8, the process 200 for designing a mockup begins with the acquisition of a virtual model of a patient’s dental arch (step 210). The virtual dental arch model may be modified to create a solid virtual mold body (step 220). A plan for treatment may be accessed or generated based at least in part on the virtual model of the patient’s dental arch (step 230). Virtual appliances are obtained and arranged on the teeth at treatment relevant locations, according to the treatment plan (step 240). The location and dimensions of one or more wells on each bonding tooth are determined based on position and orientation of the respective appliances (step 250). One or more coupling arms (i.e., sprues) are then extruded between the body of each appliance and a portion of a tooth surface within the boundaries of the well. (Step 260). A locator body is created to match the determined dimensions of the well is created at the treatment relevant locations (Step 270) The locator body, coupling arm, and appliance are combined to form a number of appliance assemblies (step 280). The dental arch and locator bodies are separated to create a virtual fixture model, including wells, for subsequent fabrication (step 290). Individual aspects of the process are discussed in further detail below.

[0090] The process 200 can be used to generate mockups at any stage of the treatment. In one example, a mockup may be generated for each phase of the treatment (and attendant placement of appliances) at the commencement of treatment. In other examples, the creation of mockups may be phased to allow for confirmation of the patient’s treatment progress, such that a new or updated model of the patient’s dentition is acquired before beginning work on a subsequent mockup. At various stages, the process for generating the original treatment plan can include interaction with the treating practitioner responsible for the treatment of the patient. Practitioner interaction can be implemented using the network platform and any connected participant.

[0091] As an initial step in creating a virtual model of the patient’s dental arch, a mold or a scan of patient's teeth (and potentially mouth tissue) is acquired (Step 210). This generally involves creating a representation of the patient's teeth and gums, and may involve taking wax bites, using impression materials, casting, direct contact scanning, x-ray imaging, tomographic imaging, sonographic imaging, and other techniques for obtaining information about the position and structure of the teeth, jaws, gums and other orthodontically relevant tissue. A digital data set can be derived from this data that represents a current arrangement of the patient's teeth and other tissues. A virtual model of the dentition may then be re-constructed based on the digital data.

[0092] One increasingly common technique for acquiring at least a portion of the initial arrangement (or any subsequent arrangement) is digital scanning. A virtual dental model representing the patient’s dental structure can be captured using a digital intraoral scan orby digitally scanning an impression or other physical dental model. Scanning devices which allow for providing a virtual dental arch in digital data form are intra-oral scanners or intra-oral contact probes, such as the True Definition™ Scanner, available from Midmark or the TRIOS scanner available from 3 Shape A / S. As another option, the digital data fde may be obtained by scanning an impression of the patient’s teeth. As another option, the digital data may be obtained by scanning a physical model of the patient’s teeth. The model used for scanning may be made by pouring a casting material (such as plaster of Paris or epoxy resin) into an impression of the patient’s teeth and allowing the casting material to cure. Any suitable scanning technique may be used for scanning the model, such as X- ray, laser, computed tomography (CT), and magnetic resonance imaging.

[0093] The digital data may be “cleansed” by removing any data points that represent clear error. For example, files in STL format representing a tooth surface that include a data point significantly outside the normal expected geometrical relationship of adjacent data points could be fixed by STL- handling software to remove the erroneous data point. In addition, tooth data points that are missing could be added by STL-handling software to create realistic, smoothly curved tooth shapes. Alternatively, or in addition to, the data cleansing may be carried out on the data file before conversion of the data to an STL file. As an additional option, data may also be obtained of hidden features of the patient, such as the roots of the patient’s teeth, the interproximal regions, and the jaw structure. For example, CT scanning techniques may be used to obtain data representative of the patient’s entire tooth structure including the roots. The data obtained by CT scanning may then be “stitched together” with other data obtained by scanning the crowns of the patient’s teeth with another scanning technique to provide a more comprehensive virtual representation.

[0094] Dentition surfaces may be segmented to produce one or more discrete, movable 3D tooth object models representing individual teeth. The tooth models may also be separated from the gingiva into separate objects. Segmentation allows a user to characterize and manipulate the teeth arrangement as a set of individual objects. Advantageously, the computer may derive diagnostic information such as arch length, bite setting, interstitial spacing between adjacent teeth, and American Board of Orthodontics (ABO) objective grading from these models.

[0095] A tooth coordinate system, defined by coordinate axes, can be defined for each discrete tooth surface in the virtual dental arch. The coordinate system may include a mesial-distal axis, a buccolabial-lingual axis, and an occlusal gingival axis for each tooth, with each axis computed as perpendicular to the other two axes. The coordinate system may be defined using computed or selected landmarks. Alternatively, the coordinate system may be created by defining a point on a virtual tooth, receiving axis input data that defines first and second axes associated with the virtual tooth, computing a substantially normal vector for a portion of the tooth surface surrounding the point, and computing the tooth coordinate system based on the axis input and the computed vector, Such methods, and well as other exemplary methods for creating tooth coordinate systems, are exemplified in US Patent No. 9,622,835 (Raby et al.). The tooth coordinate system allows for various modifications to one or more virtual teeth associated with the coordinate system. Aspects that may be adjusted or modified for each tooth include torque, tip, 1storder rotation, mesial-distal movement (with or without interproximal reduction (IPR)), occlusal-gingival translation, and buccolabial-lingual translation. Each of these aspects relate to movement in one of the six degrees of freedom defined by the coordinate axes of the respective tooth surface. Such modification also includes the positioning and / or attachment of a virtual analog to a tooth.

[0096] One or both of the occlusal and midsagittal planes of the dentition may be specified for the virtual model. The occlusal plane is an imaginary surface that passes through the occlusion of the teeth and is generally approximated by a plane. The midsagittal plane is an imaginary plane passing longitudinally through the middle of the dental arch, dividing it into left and right halves. An initial approximation of the occlusal plane may be based on the shapes or coordinate systems of some or all of the tooth surfaces belonging to an individual arch of the dentition. For example, the occlusal plane may be defined by identifying three points that tangentially contact a plane superimposed on the dentition. For a given dental arch, the three points generally include at least one contact point from a left molar, one contact point from a right molar, and one contact point from a centra, lateral, or incisor tooth. In another embodiment, the occlusal plane is defined as a best-fit plane to the points representing the origins of the tooth coordinate systems, as previously defined. In effect, this plane represents the average of these origins, which are generally positioned at the incisal edges, single cusp tips, or buccal cusp tips of the teeth. The occlusal plane may also be used to calculate and define the vertical axis of the model. The vertical axis resides in a plane perpendicular to occlusal plane and can be used to gauge the orientation of appliances on the tooth and control the orientation of the crane bodies and alignment pins.

[0097] Similarly, the midsagittal plane may be derived based on the shape of the archform according to the coordinate systems of the tooth surfaces of the dentition. Manual adjustments of the occlusal and midsagittal planes to the locations and / or orientations relative to the dentition surface can be made as desired. Area below the teeth and / or gingiva may be extruded to a planar surface to create the virtual support body (step 220). Typically, the extrusion is performed along a path generally normal to the occlusal plane to a common plane spaced about 2 to about 30 mm from the either the occlusal plane or the gingival most point on the model before creation of the support body, as desired. The creation of the support body may be accomplished before or after the virtual appliances have been placed on the arch.

[0098] The method then proceeds to setting up a treatment plan for modifying the dental arch (step 230). The treatment plan will be used to specify the dimensions, shapes, identity, and location of the appliances. The steps of the process for generating a treatment plan can be implemented as computer program modules for execution on one or more computer systems. Modeling software can provide a user interface that allows for manipulating digital representations of the teeth in 3D space relative to the digital representation of the dental arch of the patient. The treating professional generates treatment information, such as by selecting indications of the final positions of individual teeth of the patient, duration of a respective stage of treatment, or number of treatment stages, the direction or magnitude of forces on the teeth of the patient during a stage of treatment, or the like. Systems and methods for generating an orthodontic treatment plan can be found, for example, in U.S. Patent Nos. US 7,435,083 (Chisti et al.), US 7,134,874 (Chisti et al.), U.S. Patent Publication Nos. 2009 / 0286196 (Wen et al.); 2010 / 0260405 (Cinader), U.S. Patent 9,259,295 (Christoff et al.) and International Publication No. WO2021 / 245480 and WO2021 / 245484 (Cunliffe et al.). Further details on software and processes that may be used to derive a target dental arrangement are disclosed, e.g., in U.S. Patent. No. 6,739,870 (Lai et al.), U.S. Patent Nos. 8,194,067; 7,291,011; 7,354,268; 7,869,983 and 7,726,968 (Raby et al.),

[0099] The treatment planning step (step 230) typically includes receiving information regarding the orthodontic condition of a patient and / or practitioner preferences for treatment and subsequently generating an original treatment plan for repositioning the patient's teeth. This original treatment plan may represent the beginning of orthodontic treatment or may represent a new phase of treatment commenced after the patient has undergone some orthodontic or dental treatment. The treatment plan typically includes one or more phases of treatment depending on the desired treatment modality; with CTAs, the treatment plan will include multiple phases of treatment, each corresponding to an arrangement of teeth. For traditional braces or other wire driven appliance systems, the treatment plan may include a single phase, with a single target arrangement. The treatment plan is typically presented to a practitioner for modification and / or approval, though this is not strictly necessary. Appliances can be generated or selected based on the approved treatment plan, which will be provided to the practitioner and ultimately administered to the patient.

[0100] The treatment plan may be stored with other patient information in a patient dental health record (DHR). The DHR may be filled in via information from the patient and / or from treating professionals involved in the patient’s care. For example, the DHR can include, but is not limited to including, patient medical information items including x-rays, 3D models of a dental patient's dentition, and / or pictures of the patient's smile. The DHR may also include other medical information, including current and past pharmaceutical prescriptions, health history, genomic information, etc. For patient identifying information, the DHR may include patient name, address, contact information (e.g., telephone number, fax number, electronic mail address), date of birth, gender, and / or dental insurance, among others. The DHR can also include personal treatment goals of the patient (e.g., gap closure, restoration, whitening). At each stage of treatment, the DHR may be updated to reflect treatment progress and include new 3D models of the patient’s then-current dentition to aid in diagnosis and further treatment planning.

[0101] Desired final positions of the teeth, or tooth positions that are desired and / or intended end result of orthodontic treatment, can be received, e.g., from a treating professional in the form of a descriptive prescription, can be calculated using basic orthodontic prescriptions, or can be extrapolated computationally from a clinical prescription. With a specification of the desired final positions of the teeth and a digital representation of the teeth themselves, the final position and surface geometry of each tooth can be specified to form a complete model of the teeth at the desired end of treatment or treatment stage. The result of this step is a set of digital data structures that represents a desired and / or orthodontically correct repositioning of the modeled teeth relative to presumed-stable tissue. The teeth and surrounding tissue can both be represented as digital data.

[0102] Having both a beginning position and a final target position for each tooth, the process can next define a treatment path or tooth path for the motion of each tooth. This can include defining a plurality of planned successive tooth arrangements for moving teeth along a treatment path from an initial arrangement to a selected final arrangement. In one embodiment, the tooth paths are optimized in the aggregate so that the teeth are moved in the most efficient and clinically acceptable fashion to bring the teeth from their initial positions to their desired final positions. A movement pathway for each tooth between a beginning position and a desired final position may be calculated based on a number of parameters, including the total distance of tooth movement, the difficulty in moving the teeth (e.g., based on the surrounding structures, the types and locations of teeth being moved, etc.) and other patient-specific or practitioner-specific data that may be provided. Based on this sort of information, a user or a computer program may generate an appropriate number of intermediary steps (corresponding to a number of treatment steps). In some variations, the user may specify a number of steps, and the software can map different appliance configurations accordingly.

[0103] If the movement path requires that the teeth move more than a predetermined amount (e.g., 0.3 mm or less in X, Y, or Z translation), then the movement path may be divided up into multiple steps, where each step corresponds to a separate target arrangement. The predetermined amount is generally the amount that an appliance or appliance configuration can move a tooth in a particular direction in the time required for each treatment step. Each appliance configuration corresponds to a planned successive arrangement of the teeth and represents a step along the treatment path for the patient. For example, the steps can be defined and calculated so that each discrete position can follow by straight-line tooth movement or simple rotation from the tooth positions achieved by the preceding discrete step and so that the amount of repositioning required at each step involves an orthodontically optimal amount of force on the patient's dentition. The treatment plan can include a plurality of phases (1 through n) where at time=0, the initial treatment plan begins.

[0104] The user / treating professional may be offered several candidate treatment plans for selection as the original treatment plan. The candidate treatment plans can include simulations of treatment using only photographs supplied by the patient, or based on more comprehensive dental imaging (e.g., x-rays, digital scan, etc.) Candidate treatment plans may be generated using a rule-based approach, an optimization-based approach, a machine learning-based approach, or specific preferences (either patient or practitioner) as outlined in WO2021 / 245484 (Cunliffe et al.).

[0105] If the user or other professional is not entirely satisfied with the final predicted positions of the teeth, new final positions of the virtual teeth may be computed and displayed based on revised positions of either the virtual appliances or the virtual teeth. These steps can be repeated as many times as desired until all parties are satisfied. Data representing the selected positions of the teeth, along with identification data for each appliance (such as appliance type and bonding location) tooth identification data (such as tooth type and location in the oral cavity) and patient data (such as name and birth date, or a patient identification number) can be recorded in the DHR for further processing.

[0106] The methods of creating a mockup next proceeds to the step of obtaining and locating the virtual appliances relative to the virtual dental arch according to the desired treatment plan(s) (step 240). Though discussion proceeds on the basis of the virtual appliance being a virtual attachment or virtual bracket, one skilled in the art will understand that other virtual appliances suitable for bonding to the surfaces of the teeth (e.g., tubes, buttons, cleats, sheaths, bite ramps, bite blocks, etc.) may be accessed and coupled to the virtual dental arch. In an exemplary implementation, the virtual appliance is obtained based on a physical appliance standardized by prescription and available “off- the-shelf’. The person skilled in the art will however recognize that the present methods and systems may likewise be used in combination with appliances that may be customized for each tooth of each patient, or a combination of custom and standard appliances. In one implementation, virtual appliances can be selected from a library of pre-existing appliance constructions. Such fully- constructed appliances can be stored and accessible as CAD or STL (Standard Tessellation Language) files, for example. Appliances may be stored as rendered in an accessible library or generated subsequent to retrieval based on an intended location of the appliance on the dental arch. The virtual appliance may be placed on the virtual arch unmodified (i.e., that has not undergone any other shape adjustments) or may be modified after such placement.

[0107] The desired dimensions, shapes, and locations for the appliance on the model can be determined in any of several ways. Different considerations may influence the dimensions, shapes, and locations for orthodontic attachments compared to orthodontic brackets or other bonded appliances. For example, the final positions of individual teeth of the patient, duration of a respective stage of treatment, or number of treatment stages may affect the direction or magnitude of forces on the teeth of the patient at each stage of treatment. In some examples, orthodontic attachments may be used during at least one, but fewer than all stages of treatment. In some examples, the movements to be achieved, the forces applied, and the engagement of each tooth by each CTA may be determined by selecting the dimensions, shapes, and positions of an orthodontic attachment based on the treatment plan. Such analysis can be accomplished one or more times for a treatment plan. For example, it would be possible to have different attachments for each stage or possibly more, if desired. However, in many instances the attachment type, position, and / or orientation may be changed a few times during the treatment plan.

[0108] As another example, the attachments may be shaped and positioned to reduce intrusion of the tongue and / or the inside of the cheeks, particularly when a CT A is not in the mouth covering the attachments. The attachments also may be shaped and positioned to facilitate removal of the CTA from the teeth by enabling specific directional disengagement of the CTA with the attachments, e.g., which do not compromise the effectiveness of the treatment or retention of the CTA on the teeth. The attachments also may be shaped and positioned to, along with corresponding shells or aperture in the CTA, reduce visibility of the attachments when the CTA is worn by the patient. Through use of virtual modeling, attachments can be virtually tested and the best attachment type, shape, position, and / or orientation can be selected. From such analysis, different physical dental attachment placement apparatuses can be created from the virtual dental attachment placement apparatus data that would be utilized to create the attachments needed for the different stages.

[0109] In embodiments where the appliance is an orthodontic bracket, the virtual brackets can be connected to a virtual archwire, and the final positions of the teeth may be computed based on the positions of the brackets and the selected archwire. Assuming the final positions meet with approval, the virtual appliances may be placed at locations corresponding to the virtual brackets. As an alternative to moving appliances, a user may instead define the desired positions of teeth as described above, and the computer may include programming instructions to determine the suitable locations to place the appliances in order to move the teeth to those desired positions. Examples of virtual orthodontic treatment in this manner are disclosed in issued U.S. Patent Nos. 6,739,869 (Kopelman et al) and 7,354,268 (Raby et al.).

[0110] As another option, orthodontic appliances may be placed on the virtual arch model based on standards or guidelines from an orthodontic treatment philosophy, such as for example that of Drs. MacLaughlin, Bennett, and Trevisi taught in textbook “Systemized Orthodontic Treatment Mechanics” 1st Edition by Richard P. McLaughlin BS DDS, John C. Bennett FDS RCS, and Hugo Trevisi DDS. These standards or guidelines for appliance placement may be specific to each tooth in the model, and can call out the position of certain features (an occlusal-gingival height of an archwire slot, for example) with respect to the clinical crown of each tooth. The orthodontic appliances can also be placed in accordance with particular instructions provided by the treating professional. Again, these proposed orthodontic appliance locations are optionally based upon an orthodontic treatment philosophy or other known standards or guidelines in the art. Examples of automatically placing virtual brackets on teeth are described in US Patent Nos. 7,210,929 (Raby et al.), 8,517,727 (Raby et al.) and 7,940,258 (Stark et al.), all of which are hereby incorporated by reference.

[0111] The virtual appliances, whether created by the user or accessed from a virtual library, may be modified according to the treatment plan. In one embodiment, a modification step comprises increasing a three-dimensional volume represented by the virtual appliance by selectively modifying only a portion of the appliance. For example, the modification step may comprise a flattening or reduction of an indentation present in the appliance shape. The modification step may further comprise at least adding a virtual structure to the appliance shape, such as a connection points as described below. Undercuts may be minimized or removed. Further the modification step may comprise optionally reducing the three-dimensional volume by selectively modifying another portion of the appliance. The person skilled in the art will recognize various possibilities for modifying a shape, for example by change of an existing shape, adding or removing a shape, virtually copying, cutting, extending, reducing or another suitable technique. The skilled person will further be able to create a set of virtual appliances according to the treatment plan in any suitable manner.

[0112] Connection points 526 on the body 532 of the virtual appliance 530 for an eventual coupling arm can be created on the appliance before or after placement, as shown in Fig. 9. The appliance of Fig. 9 shares characteristics with the appliance of Fig. 3B, including long edges 532, 533, short edges 534, 535, base 538, facial surface 539 and long axis 540. In some implementations, connection points 526 are stored with the virtual appliance in the library. In other implementations, the connection points may be added during modification of the appliance or after the appliance has been positioned and oriented according to the treatment plan. The number and location of connection points typically follows the same considerations for sprues and can be dictated by at least one of (a) the orientation of the long axis 540 of the appliance relative to an axis perpendicular to the base plane B; (b) the orientation of the long axis 540 relative to vertical axis V; and (c) the dimensions of the appliance, all according to the treatment plan. The connection points 526 have a cross-sectional shape (here, ovular) generally matching the preferred cross-sectional shape of the eventual coupling arm; this allows the coupling arm to be extruded directly from the appliance body as further explored below.

[0113] Turning to Fig. 10, a virtual mold body 500 is depicted with virtual appliances 530 (here having all features of attachments 30) dimensioned, shaped, and located according to the treatment plan on labial tooth surfaces 517 of associated teeth 513. At any point in the process after an appliance location has been satisfactorily confirmed, a virtual locator body 560 (See Fig. 1 la) may be created and / or placed on an appropriate location on the virtual fixture model. The placement location of the locator body 560 will then correspond to the location of the well 570 (See Fig. 1 lb). As detailed above, the appropriate location for the locator body depends on the appliance geometry, position, and orientation on the bonding tooth, as well as the expected stability of the coupling arm extending between the locator body and the appliance. The placement of the locator body may occur prior to or after the extrusion of one or more coupling arms from the appliance body.

[0114] The geometry of the locator body may be used to create a well 570 in the bonding surface 517, and vice versa. For instance, the virtual locator body can be Boolean subtracted from the virtual tooth, leaving a well having a shape matching the geometry of the locator body 560. Alternatively, a volume of a locator body can be Boolean subtracted from the tooth (or other area of the virtual mold body) and subsequently joined to the appliance via a coupling arm. As another alternative, the virtual well and virtual locator body may be created independently according to the prescribed, cooperating dimensions of their physical counterparts. Other methods for creating a well having the shape of the locator body will be apparent to the skilled artisan.

[0115] Each virtual spme 520 may be extruded between the appliance body 531 and the locator body 560, or may be extruded from the appliance body 531 and subsequently coupled to a locator body 560. The sprues generally retain the cross-sectional shape of connection points 526, if used, and may include a taper, each as noted above. Also as noted above, spmes may be linear, arcuate along a single radius of curvature, include compound curvature, or include combinations of the same. Once each appliance 530 is attached via the requisite number of sprues to the locator body 560, a complete virtual mockup is available for further manufacturing.

[0116] With a complete virtual mockup in place, the method proceeds to create at least two separate object models exportable for subsequent manufacturing: a) fixture model comprising the mold body and associated well(s); and b) each appliance assembly 600 including the grouped appliance, coupling arms, and locator body (see e.g., Fig. I la). These components of the virtual mockup are typically exported and fabricated separately, with the creation of the complete physical mockup 10 requiring the subsequent placement of each appliance assembly on the fixture model.

[0117] The fixture model can be provided by combining the virtual constituent elements, for example being merged or superimposed by computer aid. The virtual fixture model can be maintained in the form of a computer processable three-dimensional data file, may be transmitted to a fabrication machine which manufactures a physical representation thereof.

[0118] The fixture model and appliance assembly objects may each be provided by combining the virtual constituent elements, for example being merged or superimposed by computer aid. The virtual fixture model and appliance assembly can each be maintained in the form of a computer processable three-dimensional data file, may be transmitted to a fabrication machine which manufactures a physical representation thereof. In some examples, the fabrication of the fixture model from the virtual mockup may include a 3D printing process. In presently preferred implementations, the fixture model including appliances is created through 3D printing, with dental arch model and the appliances created through from same material. Suitable materials for each are described above.

[0119] Three-dimensional printing may include, for example, forming the fixture model from a plurality of layers of a photopolymerizable material described herein by selectively curing the photopolymerizable material in a layer-by-layer manner. In some examples, an additive manufactured article may include a plurality of materials bonded to each other. The layers of the photopolymerizable material can be deposited according to an image of the three-dimensional article in a computer readable format. For example, the photopolymerizable material may be deposited according to preselected computer aided design (CAD) parameters (e.g., a data file). In some examples, the photopolymerizable material is cured using actinic radiation, such as UV radiation, e- beam radiation, visible radiation, or combinations thereof.

[0120] Additionally, it is to be understood that methods of manufacturing a 3D article described herein can include stereolithography or vat polymerization. For example, the methods of the present disclosure may include retaining a photopolymerizable composition described herein in a fluid state in a container and selectively applying energy to the photopolymerizable composition in the container to solidify at least a portion of a fluid layer of the photopolymerizable composition, thereby forming a hardened layer that defines a cross-section of the 3D article. The methods also may include raising or lowering the hardened layer of photopolymerizable composition to provide a new or second fluid layer of unhardened photopolymerizable composition at the surface of the fluid in the container, followed by again selectively applying energy to the photopolymerizable composition in the container to solidify at least a portion of the new or second fluid layer of the photopolymerizable composition to form a second solidified layer that defines a second crosssection of the 3D article. Further, the first and second cross-sections of the 3D article can be bonded or adhered to one another in the z-direction (or build direction corresponding to the direction of raising or lowering recited above) by the application of the energy for solidifying the photopolymerizable composition. Moreover, selectively applying energy to the photopolymerizable composition in the container can include applying actinic radiation, such as UV radiation, visible radiation, or e-beam radiation, having a sufficient energy to cure the photopolymerizable composition. The methods of creating the physical mockup also may include planarizing a new layer of fluid photopolymerizable composition provided by raising or lowering an elevator platform. Planarization can be carried out, for example, by utilizing a wiper or roller or a recoater. Planarization may correct the thickness of one or more layers prior to curing the material by evening the dispensed material to remove excess material and create a uniformly smooth exposed or flat up- facing surface on the support platform of the printer. The foregoing techniques can be repeated a selected number of times to provide the 3D article. For example, in some cases, this process can be repeated “n” number of times. Further, it is to be understood that one or more steps of a method described herein, such as a step of selectively applying energy to a layer of photopolymerizable composition, can be carried out according to an image of the 3D article in a computer-readable format. Suitable printers include the Viper Pro SLA, available from 3D Systems, Rock Hill, South Carolina; the Asiga PICO PLUS 39, available from Asiga USA, Anaheim Hills, California; the D30 II, available from Rapid Shape, Heimsheim, Germany; and the Moomay, available from SprintRay, Los Angeles, California.

[0121] A related technology, vat polymerization with Digital Light Processing (“DLP”), also employs a container of curable polymer (e.g., photopolymerizable composition). However, in a DLP based system, a two-dimensional cross section is projected onto the curable material to cure the desired section of an entire plane transverse to the projected beam at one time. All such curable polymer systems as may be adapted to use with the photopolymerizable compositions described herein are intended to fall within the scope of the term “vat polymerization system” as used herein.

[0122] One, some, or all of the appliances, locator bodies, and dental arch model may be created on a build platform of any suitable shape. For example, the build platform may include a substantially planar plate, one or more elongate runners, or the like. Build platforms may also include frangible sprues which support mockup components fabricated on the build platform. Build platform sprues, like those connecting the appliance to the bonding tooth, are configmed to break in response to a bending, twisting, compression, or tension. The build platform may include indicia identifying the physical mockup components thereon. The indicia may include text, symbols, coloring, or the like. For example, the build platform may be formed by the additive manufacturing techniques described herein to include text embossed on a surface of the build platform to indicate the patient or phase of treatment.

[0123] Other techniques for three-dimensional manufacturing, including but not limited to fused deposition modeling, selective laser sintering, and inkjet printing, may be suitably adapted to the methods described herein. More generally, three-dimensional fabrication techniques continue to become available and may be adapted to use with photopolymerizable compositions described herein, provided they offer compatible fabrication viscosities and resolutions for the specified article properties, for instance continuous additive manufacturing in which a build plate is (essentially) continuously moved through a vat of photopolymerizable material. In certain examples, an apparatus adapted to be used in a continuous mode may be employed, such as an apparatus commercially available from Carbon 3D, Inc. (Redwood City, CA), for instance as described in U.S. Patent Nos. 9,205,601 and 9,360,757 (both to DeSimone et al.). For example, in any method described above, selective curing of a photopolymerizable material includes continuous photopolymerization of at least one of the first portion of the article or the second portion of the article.

[0124] After a three-dimensional article has been formed, it is typically removed from the additive manufacturing apparatus. At this stage, the three-dimensional article typically has sufficient green strength for handling in any remaining steps of the method. The article surface, as well as the bulk article itself, typically still retain uncured material, suggesting a need for further curing. Removing residual uncured photopolymerizable material is particularly useful when the article is going to subsequently be post-cured, to minimize uncured residual material from undesirably curing directly onto the article. A “cured” article can include a photopolymerizable material that has been at least partially polymerized and / or crosslinked. For instance, in some instances, an at least partially polymerized article is at least about 10% polymerized or crosslinked or at least about 30% polymerized or crosslinked. In some cases, an at least partially polymerized article is at least about 50%, at least about 70%, at least about 80%, or at least about 90% polymerized or crosslinked, for instance between about 10% and about 99% polymerized or crosslinked.

[0125] In some examples, removal of excess uncured photopolymerizable composition on the additive manufactured article is at least partially performed by washing with at least one solvent. Suitable solvents include, but are not limited to, propylene carbonate, isopropanol, methanol, di(ethylene glycol) ethyl ether, tripropylene glycol monomethyl ether, diethylene glycol monobutyl ether, a blend of dipropylene glycol monomethyl ether with [2-(2- methoxymethylethoxy)methylethoxy]propanol, and combinations thereof. In certain examples, the removal is performed at least partially by moving the additive manufactured article and thereby generating a mass inertial force in uncured photopolymerizable composition on the article, wherein the mass inertial force is generated using a centrifuge, a shaker, or a mixer that spins along one or more axes. Suitable ways of generating a mass inertial force are described, for instance, in International Publication No. 2020 / 157598 (Chakraborty et al.), incorporated herein by reference in its entirety. For instance, the source of the mass inertial force may be generated using a centrifuge, a shaker, or a mixer that spins along one or more axes. In some examples, the moving of the object is a rotation or spinning of the object. Accordingly, the mass inertial force may be generated by a centrifugal force. One suitable mixer that spins along more than one axis is a dual asymmetric centrifugal mixer, such as the DAC 400 FVZ available from Flacktek, Landrum, SC. A dual asymmetric centrifugal mixer provides simultaneous dual axis spinning that automatically reorients the article during spinning, which tends to pull uncured composition out of concave features of the article in a short period of time (e.g., 20, 15, or 10 seconds or less). Suitable cleaning solutions are also described in International Publication No. WO 2018 / 222395 (Jahns et al.) The methods of the present disclosure also may include subjecting the additive manufactured article to actinic radiation, heat, or both to photopolymerize uncured photopolymerizable composition. Optionally, that can be followed by soaking the article with another solvent (e.g., diethylene glycol ethyl ether or ethanol). Exposure to actinic radiation can be accomplished with any convenient radiation source, generally UV radiation, visible radiation, and / or e-beam radiation, for a time ranging from about 10 seconds to over 60 minutes. Heating is generally carried out at a temperature in the range from about 35°C to about 80°C, for a time ranging from about 10 to over 60 minutes in an inert atmosphere, optionally under vacuum. In some examples, post-cure ovens, which combine UV radiation and thermal energy, may be used for post-cure processes. In some examples, post curing may improve the mechanical properties and stability of the three-dimensional article relative to the same three-dimensional article that is not post cured.

[0126] In some examples, the photopolymerizable material includes a ceramic material (e.g., ceramic particles and / or ceramic fibers), and the method further includes burning out polymerized material and sintering the additive manufactured article to form a ceramic article.

[0127] Regarding any method described above, the steps further optionally include polishing the additive manufactured article, to render at least a portion of a surface of the additive manufactured article smoother than prior to the polishing. Moreover, the methods may further include a treatment of the bonding surface 38 of one or more appliances 30 to improve surface roughness and mechanical retention. Such treatments may include etching, an organo -silane treatment, sandblasting, or any other known mechanical or chemical modification to enhance adhesive bonding between the base 38 and the bonding tooth. For sandblasting, treatment includes blasting the bonding surface with an alumina or silica-coated alumina sandblasting medium. A solution of silane (e.g., a silane in ethanol) can then be applied to the treated surface and allowed to dry at room temperature for at least 5 minutes. In the same or other implementations, the base may be bonded to compressible material to assist in filling gaps between the base and the tooth structure. Suitable compressible materials are described in US Patent No. 9,480,540 (Cinader).

[0128] Creating a Transfer Apparatus from a Physical Mockup.

[0129] Once the components are fabricated and post-processed as desired, the methods move on to the joining of the fixture model and appliance assemblies to create the physical mockup 10. Each appliance assembly is placed on or adjacent a bonding tooth such that the locator body 60 engages and is received in the well the well 70. The appliance assemblies may be arranged one by one or joined and arranged in one or more groupings. Appliance assemblies may be placed manually by a technician using e.g., indicia on the carrier assembly and / or fixture, or according to guidelines specifying the location of a given appliance assembly based on e.g., appliance geometry or locator body geometry. For example, a clinician or technician may use a tool such as a tweezer, a retaining ring pliers, or other suitable tool to engage the locator body / appliance body to arrange the appliance assembly on the fixture model. As an alternative to manual placement of appliance assemblies, a computer controlled robotic arm (e.g., a pick and place robot) may be used to grasp each appliance in sequence and place it on the associated tooth. For example, information regarding the placement of the combined appliance assembly can be used in a set of instructions to control movement of the robotic arm such that the appliance is placed on the corresponding, selected location of the fixture model.

[0130] With each locator body placed in the associated well, each appliance is predictably located at its intended bonding position and orientation on the bonding tooth surface. If the physical mockup is generated to satisfaction, a transfer apparatus may be created over said mockup. This may include sending instructions to a pressure forming or thermoforming machine to cause one or more sheets of material to be pressure formed or thermoformed over the physical mockup to form a negative replica or shell. The sheet may be, for example, a sheet of deformable plastic (e.g., an elastic thermoplastic). The sheet of material may be heated to a temperature at which the sheet becomes pliable. Pressure may concurrently be applied to the sheet to form sheet around the mockup. Once the sheet cools, it will have a shape that conforms to the mockup. An interior shape of the plastic shell substantially conforms to the patient’s current dental arch. A release agent can be applied to the mockup before forming the plastic shell to facilitate later removal of the plastic shell from the mockup. The shell can be trimmed by laser or mechanical milling techniques to remove excess or unwanted material.

[0131] One exemplary method of making a transfer apparatus in the form of a tray includes the use of multiple sheet materials as described in US Patent No. 10,368,961 (Paehl et al.). The method includes placing elastic sheeting on top of the occlusal side of the teeth represented by the physical mockup, with a plastic sheeting arranged on top of the elastic sheeting. The elastic sheeting and the plastic sheeting are deformed in directions toward the physical mockup. This may be achieved by a vacuum generated beneath the elastic and plastic sheeting or a pressure above the elastic and plastic sheeting. At least the plastic sheeting maybe heated before and / or during the deformation. The plastic sheeting is typically allowed to solidify by cooling so as to provide it with a sufficient rigidity for handling.

[0132] The method can, in other embodiments, optionally include placing an elastomeric spacer over the physical mockup and thermoforming the hard layer of a transfer apparatus (such as, for example, PETG) over the mockup. The spacer material can be any one of a number of materials including dental putty, a thermoset material, thermoplastics (including nylons), a thermoplastic elastomer, and composites (e.g., glass-filled nylons). Further details regarding the spacer may be found in US Patent No. 7,762,815 (Cinader et al.)

[0133] Optionally, the transfer apparatus may be created having an occlusal stop member, also as described in US Patent No. 7,762,815. An occlusal stop member typically includes a flat top surface and a bottom surface with shapes such as recesses that match the shapes of the occlusal tips of the patient’s dental arch. In certain implementations, the occlusal stop member has a recess or recesses corresponding to only some of the teeth in the dental arch, although it is also possible to construct an occlusal stop member that has one or more recesses corresponding to each tooth of the dental arch. Other variations are also possible. For example, the occlusal stop member may extend only along a portion of the dental arch instead of along the entire dental arch. A plurality of stop members may be provided, potentially spaced apart from each other and optionally connected. The occlusal stop member may be chemically or mechanically bonded to the plastic sheeting and / or the hardenable material.

[0134] It should be appreciated that the transfer tray may be formed only of one or more layers of deformable plastic sheeting, without an accompanying elastic sheeting or soft positioning layer. In such implementations, the plastic sheeting may be disposed directly proximate the occlusal surface of the physical mockup, without the spacing provided by elastic sheeting. The plastic sheeting accordingly directly embraces the teeth and appliances of the physical mockup upon deformation, directly creating receptacles used to removably retain appliances for subsequent bonding. In such streamlined transfer apparatus embodiments, the physical mockup may be coated with a release agent to assist in removal of the transfer tray from the mockup. Pursuant to typical methods used to create the transfer apparatus, the resulting tray represents a negative replica of at least a portion of the physical mockup.

[0135] Suitable materials for creating a thermoformed transfer apparatus are well known in the art and the selection of material is accordingly not critical. In exemplary implementations, the transfer apparatus is formed from Copyplast™ low density polyethylene, available from Scheu Dental Group, Iserlohn, Germany. Use of transparent materials for the component layers may facilitate confirmation of proper placement of the transfer apparatus and associated appliances on the teeth.

[0136] Alternatively, the transfer apparatus may comprise a dental impression material or a bite registration material. A dental impression material can be based on different chemical substances and crosslinked by various chemical reactions (including addition curing and condensation curing materials). Dental impression materials can be classified according to their curing mechanism (e.g., addition curing or condensation curing). Dental impression materials can also be classified according to their consistency. Besides low viscous dental impression materials, there exists highly viscous, so-called putty like dental impression materials. Examples of dental impression material include materials based on alginate(s), hydrocolloids, polysulfides, polyether technology, addition curable silicone materials (e.g., VPS materials) and condensation curable silicone materials. Dental impression materials are typically provided as two component systems that consist of a base paste and a catalyst paste and which are mixed prior to their application. The mixed pastes are typically applied with the help of a syringe-type device.

[0137] Dental impression materials are typically characterized by at least one, more or all of the following features: Consistency (according to ISO 4823): comparable low viscosity behavior (consistency 3), a medium viscosity (consistency 1 or 2) or putty-like, highly viscous behavior (consistency 0); Setting time: within about 15 min after mixing at ambient conditions (e.g., 23° C.); Shore A hardness (according to ISO 4823; 24 h): at least about 20 or at least about 40; Tensile strength (according to DIN 53504): at least about 0.2 MPa or at least about 3.0 MPa; Elongation at break (according to DIN 53504): at least about 30% or at least about 150% or at least about 200%; Recovery from deformation (according to ISO 4823): at least about 90% or at least about 95% or at least about 98%. Suitable dental impression materials are also described in EP2072029 (Bissinger et al), U.S. Pat. No. 6,677,393 (Zech et al), EP1512724 (Zech et al), U.S. Pat. No. 6,127,449 (Lechner et al), US Pat. No. 8,007,579 (Klettke et al.) and U.S. Pat. No. 5,569,691 (Guggenberger et al). Suitable dental impression materials are commercially available, e.g., from 3M ESPE under the brands Impregum™ or Imprint™, as well as myriad other suppliers and brands.

[0138] In alternative methods, the transfer apparatus may be created through additive manufacturing techniques and the fixture model used to place appliances in the formed transfer apparatus. Suitable methods for designing and additively manufacturing a transfer apparatus canbe found, for example, in International Publication Nos. WO2009158231 (Raby et al.) and WO2021130624 (Cinader et al.).

[0139] After the transfer apparatus has cured or otherwise solidified, the apparatus is removed from the fixture model. The coupling arms connecting the appliance to the model may be broken before or during the apparatus removal. In some embodiments, the coupling arm is cleaved at the appliance body. In other embodiments, the coupling arm is cleaved at or adjacent the locator body. The appliances are retained in the apparatus by virtue of at least intimate contact between the transfer apparatus material and the appliance body. As noted above, this contact may be enhanced by retention features on the surfaces of the appliances. The shell can be trimmed by laser or mechanical milling techniques to remove excess or unwanted material before or after removal.

[0140] Figs. 12 and 13 depict a finished transfer apparatus 1100 and a cross-section of one receptacle 1120, respectively. The formed transfer apparatus 1100 (here, a U-shaped tray) substantially matches surfaces of the teeth of the physical mockup. The body of the transfer apparatus 1100 defines a plurality of shells 1150. Each respective shell of shells 1150 is configmed to receive an outer surface of a respective tooth. In this way, the transfer tray is configured to align with the dentition of a patient. The inner wall sections of the apparatus 1100 will typically have contours that match the contours of the individual teeth of the patient, as well as an overall configuration that matches the orientation of each tooth relative to other teeth in the same dental arch. The inner wall sections will contact at least two of the labial, occlusal and lingual surfaces of the teeth when seated on the dental arch, though other constructions may omit the one or two of those surfaces.

[0141] Each shell of shells 1150 that aligns with a bonding tooth is configmed to include a respective receptable 1120 within shells 1150 that is shaped to envelop at least a portion of the respective appliance 1230. In some examples, shell receptacles 1120 may include a feature, such as an undercut or a protrusion, that is configured to engage with a corresponding feature on an appliance 1230. For example, attachment body 1231 may define an undercut (e.g., undercut 1249 created by a retention feature stem 1246 and cap 1248) and a surface of shell recesses 1120 may define a protrusion configured to engage the undercut.

[0142] The receptacles 1120 may have any suitable cross-sectional shape or combination of shapes (e.g., trapezoidal, dome-shaped, etc.) but that shape generally corresponds to the shape of associated appliance body 1231, including optional retention stem 1246 and cap 1248. Each receptacle 1120 in the transfer apparatus may each have the same or different cross-sectional shape. In other embodiments, certain groups of receptacles 1120 may include the same cross-sectional shape amongst one another in the group, and have a different cross-sectional shape from the cross-sectional shape of a group situated in a different quadrant or location on the transfer apparatus 1100. In presently preferred circumstances, the apparatus lacks any interior surfaces in the receptacle 1120 disposed between the base of the appliance 1230 and the bonding tooth surface; this configmation may aid in the separation of the appliance 1230 from the transfer tray 1100.

[0143] In some embodiments, the receptacle may include a channel 1130 in communication with the receptacle 1120. The channels 1130 may have any suitable cross-sectional shape or combination of shapes (e.g., trapezoidal, dome-shaped, etc.) but that shape generally corresponds to the shape and dimensions of the coupling arms (or portion thereof) connecting the appliance and locator body. The sprue will generally remain in the channel 1130 after the appliance 1230 has been bonded to the requisite as described below.

[0144] A transfer apparatus need not extend over all exterior surfaces of the appliances. An apparatus may include a combination of such partially exposed appliances, and appliances wholly enveloped in received receptacles. Leaving the appliance 1230 at least partially exposed may, in certain implementations, ease the separation of the appliance 1230 from the transfer apparatus when the appliance 1230 is adequately bonded to the bonding tooth. Additionally, the transfer apparatus may be used for bonding only a single appliance to a patient’s tooth. For example, a portion of the transfer apparatus described above may be used to bond a single appliance to a single tooth subsequent to the time that other appliances are bonded, such as in instances where access to the tooth is initially hindered by other teeth. As another example, a portion of the transfer apparatus described above may be used to re-bond one or more appliances that have unintentionally debonded from the tooth, or to bond a new appliance to a tooth to replace the original appliance.

[0145] Adhesive may be applied to one or both of the bonding surface of the appliances 1230 and the patient’s tooth surface prior to seating the tray on the patient’s dental arch. In some examples, dental adhesive used may include a light-cure adhesive, a chemical cure adhesive, a dual cure adhesive, 3M RELYX Ultimate Adhesive Resin Cement, SCOTCHBOND Universal Adhesive, TRANSBOND XT Primer, TRANSBOND MIP Primer, or APC FLASH-FREE adhesive, all available from 3M Company (St. Paul, Minnesota), or the like. The adhesive may be selected for compatibility with the material used to fabricate the appliance to securely bond attachments onto teeth. After application of adhesive to bonding surfaces, transfer apparatus 1100 may be positioned on the teeth of a patient.

[0146] A clinician or any other treating professional may first position transfer apparatus 1100 on dentition. Then, in examples in which the dental adhesive includes a light cure adhesive, the clinician may direct a selected wavelength of radiation, e.g., actinic radiation, toward one or more of appliances 1230 to cause a light-activating resin to set, thereby bonding appliance 1230 to the bonding tooth surface. In other embodiments, the adhesive is a two-part adhesive, with components mixed prior to application of the adhesive to the appliance and / or the teeth. In other examples, the clinician may use an activator or other means to initiate curing of the adhesive immediately before positioning transfer apparatus 1100 on the arch or while transfer apparatus 1100 is positioned on the arch. The teeth may optionally be etched or primed before the transfer tray is seated on the arch.

[0147] Once the adhesive is suitably cured, each appliance 1230 may be separated from the associated receptacle 1120. The apparatus is removed from the arch and patient’s mouth. The treating professional may then remove any undesired vestiges of the coupling arms.

[0148] Kits and assemblies of the appliance described are also contemplated herein. For example, one or more of the attachments described herein may be pre-coated with a suitable orthodontic adhesive and packaged in a container or a series of containers, as described for example in U.S. Patent Nos. 4,978,007 (Jacobs et al.); 5,015,180 (Randklev); 5,429,229 (Chester et al.); and 6,183,249 (Brennan, et al.), and U.S. Patent Publication No. 2008 / 0286710 (Cinader et al.).

[0149] Various techniques of this disclosure may be implemented in a wide variety of computer devices, such as servers (including the Cloud), laptop computers, desktop computers, notebook computers, tablet computers, hand-held computers, smart phones, and the like. Any components, modules or units have been described to emphasize functional aspects and does not necessarily require realization by different hardware units. The techniques described herein may also be implemented in hardware, software, firmware, or any combination thereof. Any features described as modules, units or components may be implemented together in an integrated logic device or separately as discrete but interoperable logic devices. In some cases, various features may be implemented as an integrated circuit device, such as an integrated circuit chip or chipset.

[0150] If implemented in software, the techniques may be realized at least in part by a non- transitory computer-readable medium comprising instructions that, when executed in a processor, performs one or more of the methods described above. The computer-readable medium may comprise a tangible computer-readable storage medium and may form part of a computer program product, which may include packaging materials. The computer-readable storage medium may comprise random access memory (RAM) such as synchronous dynamic random access memory (SDRAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), FLASH memory, magnetic or optical data storage media, and the like. The computer-readable storage medium may also comprise a non-volatile storage device, such as a hard-disk, magnetic tape, a compact disk (CD), digital versatile disk (DVD), Blu-ray disk, holographic data storage media, or other non-volatile storage device. The term “processor,” as used herein may refer to any of the foregoing structure or any other structure suitable for implementation of the techniques described herein. In addition, in some aspects, the functionality described herein may be provided within dedicated software modules or hardware modules configured for performing the techniques of this disclosure. Even if implemented in software, the techniques may use hardware such as a processor to execute the software, and a memory to store the software. In any such cases, the computers described herein may define a specific machine that is capable of executing the specific functions described herein. Also, the techniques could be fully implemented in one or more circuits or logic elements, which could also be considered a processor.

[0151] The patents, patent documents, and patent applications cited herein are incorporated by reference in their entirety as if each were individually incorporated by reference. Although specific embodiments of the present disclosure have been shown and described herein, it is understood that these embodiments are merely illustrative of the many possible specific arrangements that can be devised in application of the principles of the present disclosure. Numerous and varied other arrangements can be devised in accordance with these principles by those of ordinary skill in the art without departing from the spirit and scope of the present disclosure. Thus, the scope of the present disclosure should not be limited to the structures described in this application, but only by the structures described by the language of the claims and the equivalents of those structures.

Claims

WHAT IS CLAIMED IS:

1. A physical mockup for creating a transfer apparatus, the mockup comprising: a representation of at least a portion of a dental arch of a patient, the dental arch including a bonding tooth, and an appliance arranged on or near a surface of the bonding tooth; wherein the bonding tooth includes a well extending a depth into the tooth volume, and a locator body received in the well, wherein the appliance is frangibly connected to the locator body.

2. The mockup of claim 1, wherein the appliance is connected to the locator body via one or more coupling arms.

3. The mockup of claim 2, wherein the appliance includes a base and a body, and wherein the coupling arms extend between a body of the appliance and an outer surface of the locator body.

4. The mockup of claim 2, wherein at least one sprue includes a first segment and a second segment pivoted relative to the first segment.

5. The mockup of any of the previous claims, wherein the appliance is connected to the locator body via a single coupling arm, and wherein a cross-sectional area of the sprue is less than one half an area of the outer surface of the locator body.

6. The mockup of any of the previous claims, wherein the well is dimensioned and shaped to releasably retain the locator body.

7. The mockup of any of the previous claims, wherein a portion of bonding tooth surface is provided by the outer surface of the locator body.

8. The mockup of any of the previous claims, wherein a three-dimensional shape of the well matches the three-dimensional shape of the locator body.

9. The mockup of claim 8, wherein the locator body has a generally frustoconical or pyramidal shape.

10. The mockup of any of the previous claims, wherein the depth of the well is about 1 mm.

11. The mockup of any of the previous claims, wherein the well is located in the tooth in an occlusal or gingival direction from the appliance.

12. The mockup of any of the previous claims 1-10, wherein the well is located in the tooth in a mesial or distal direction from the appliance.

13. The mockup of any of the previous claims, wherein the appliance and locator body are comprised of the same material.

14. The mockup of any of the previous claims, wherein the appliance, locator body, and the tooth are formed by three-dimensional printing.

15. The mockup of claim 1, wherein the well includes an opening in the tooth surface.

16. The mockup of claim 15, wherein the opening is on a facial surface of the tooth.

17. The mockup of claim 16, wherein the tooth has a height of contour, and wherein the opening is above the height of contour.

18. The mockup of claim 16, wherein mockup includes a representation of gingiva, and the opening is adjacent to or within the gingiva.

19. The mockup of any of the previous claims 1-16, wherein the opening is on an occlusal surface of the tooth.

20. The mockup of any of the previous claims, wherein the appliance is an orthodontic attachment.

21. The mockup any of the previous claims, wherein the dental arch includes a plurality of teeth, and wherein each tooth of the plurality of teeth includes an appliance, a well, and a locator body frangibly connected to the appliance and retained in the well.

22. A method for creating a transfer tray for one or more orthodontic appliances, the method comprising: providing a physical mockup for creating a transfer apparatus, the mockup comprising: a representation of at least a portion of a dental arch of a patient, the dental arch including a bonding tooth, wherein the bonding tooth includes a well extending a depth into the bonding tooth volume, providing a locator body frangibly connected to an orthodontic appliance via one or more coupling arms; inserting the locator body into the well such that the orthodontic appliance is arranged on or near the bonding tooth surface; and forming a tray over the mockup.

23. The method of claim 22, and further comprising removing the tray from the mockup.

24. The method of claim 23, wherein removing the tray from the mockup includes the step of separating the appliance from the locator body.

25. The method of claim 22, wherein separating the appliance from the mockup includes breaking one or more coupling arms connecting the locator body to the appliance.

26. The method of claim 25, wherein breaking one or more coupling arms includes cleaving one sprue of the one or more coupling arms at the surface of the locator body.

27. The method of claim 26, wherein breaking one or more coupling arms includes cleaving one coupling arm of the one or more coupling arms at the surface of the appliance.

28. The method of any of the previous claims, wherein providing the locator body comprises additively manufacturing the locator body, coupling arm, and appliance as a single article.

29. The method of claim 28, wherein the locator body, coupling arm, and appliance are composed of a first material.

30. The method of claim 29, wherein the mockup is composed of the first material or a second material.

31. The method of any of the previous claims, wherein inserting the locator body into the well comprising inserting the locator body in a generally lingual direction.

32. The method of any of the previous claims, wherein inserting the locator body into the well comprising inserting the locator body in a generally gingival direction.

33. The method of any of the previous claims, wherein, after inserting the locator body into the well, the locator body is located in the tooth in an occlusal or gingival direction from the appliance.

34. The method of any of the previous claims 23-33, wherein, after inserting the locator body into the well, the locator body is located in the tooth in a mesial or distal direction from the appliance.

35. The method of any of the previous claims, wherein, after inserting the locator body into the well, a portion of bonding tooth surface is provided by the outer surface of the locator body.

36. The method of any of the previous claims, wherein a three-dimensional shape of the well matches the three-dimensional shape of the locator body.

37. The method of claim 36, wherein the locator body has a generally frustoconical or pyramidal shape.

38. The method of any of previous claims, and further comprising placing a bonding agent on at least one of a surface of the well and a surface of the locator body.

39. A method of making a physical mockup, the method comprising: acquiring a virtual, 3 -dimensional model of a patient’s dentition, the model including a representation of a tooth having a 3 -dimensional volume; determining a bonding location for an orthodontic appliance on an outer surface of the tooth; selecting an area of the tooth adjacent to the bonding location; removing a portion of the tooth volume at the selected area to create a locator body geometry; connecting a surface of the locator body to the appliance via a coupling arm; and subtracting the locator body from the tooth volume to create a well in the tooth.

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