IPC分类号：
B29C64/393 | A61C7/00 | A61C7/28 | A61C9/00 | A61C13/34 | B28B1/00 | B28B17/00 | B33Y10/00 | B33Y50/00 | B33Y50/02 | B33Y80/00 | B29L31/00
当前申请(专利权)人：
LIGHTFORCE ORTHODONTICS, INC.
原始申请(专利权)人：
LIGHTFORCE ORTHODONTICS INC.
当前申请(专利权)人地址：
44 3RD AVE., 01803, BURLINGTON, MASSACHUSETTS
发明人：
VANNOY, SAMUEL | WINCHELL, DYLAN | FAFARA, KELSEY A. | DUGGAN, OISIN | GRIFFIN, III, ALFRED CHARLES
代理机构：
WOLF, GREENFIELD & SACKS, P.C.
摘要：
Embodiments relate to the methodology of direct manufacture of a customized labial/lingual orthodontic tube by using a ceramic slurry-based additive manufacturing (AM) technology. For example, a method of manufacturing customized ceramic labial/lingual orthodontic tubes by additive manufacturing may comprise measuring dentition data of a profile of teeth of a patient, based on the dentition data, creating a three-dimensional computer-assisted design (3D CAD) model of the patient's teeth, and saving the 3D CAD model, designing a virtual 3D CAD tube structure model for a single labial or lingual tube structure based upon said 3D CAD model, importing data related to the 3D CAD tube structure model into an additive manufacturing machine, and directly producing the tube with the additive manufacturing machine by layer manufacturing from an inorganic material including at least one of a ceramic, a polymer-derived ceramic, and a polymer-derived metal.
技术问题语段：
Because the tube pad is typically not custom made for an individual patient's tooth, the clinician is responsible for the tube placement, which may introduce a source of error, which commonly increases patient visits and overall treatment time.|A misplacement in bonding a tube to a tooth can be corrected by compensation bends in the wire or by debonding and repositioning of the tube, both of which increase time and cost.|Selective laser melting (SLM) is a 3DAM technique that has been used to create custom metal lingual brackets and tubes (for example, see U.S. Pat. No. 8,694,142), but this technique suffers from insufficient resolution and surface finish.|While true custom labial tubes have been used, custom positioning of a standard, non-custom tube can be created via indirect bonding which itself has inherent error within the tube itself.|These partially custom metal brackets and tubes (akin to tubes) suffer from inaccuracy in slot position and premature debonding due a stock base that doesn't match the tooth morphology, and are unappealing to older patients who prefer to have non-metal appliances for aesthetic concerns.|However, non-customized ceramic tubes have only been available since 2018 as the need for an aesthetic alternative to metal is not as concerning to patients due to their location in the bracket of the mouth.|Ceramic brackets and tubes are predominantly manufactured by injection molding, which has manufacturing limitations.|For example, it may be difficult or impossible to use injection molding to create undercuts that may enhance a tube's mechanical bond strength to a tooth adhesive.|Due to the mechanical properties of ceramic and this debond mechanism, there is a higher risk of enamel damage when debonding a tube if the tube does not easily separate from the tooth.|In this case a diamond burr is necessary to drill the tube off the tooth which can create sparks, take a long time, and result in a poor patient and provider experience.|Currently, there are no commercially available ceramic tubes which debond via a controlled fracture along a form of ‘stress concentrator’ designed to force the tube to break at a particular location when pressure is applied.|A static shape for the stress concentrator does not provide a consistent debonding experience depending on the thickness (in-out) of the tube and its exact position on the tooth, and thus a custom shape must also be used.
技术功效语段：
[0004]Some embodiments of the present invention provide improved techniques for creating custom lingual or labial ceramic orthodontic tubes, and which provides the capability for in-office fabrication of such tubes.
权利要求：
1. A method of manufacturing customized orthodontic tubes for patients, the method comprising:
obtaining a three-dimensional (3D) model of one or more teeth of a patient;
generating a 3D model of an orthodontic tube structure using the 3D model of the one or more teeth of the patient, the orthodontic tube structure comprising a curved gingival base edge, the base edge being curved to approximate a gingival margin of a tooth of the patient; and
using an additive manufacturing device to produce a customized orthodontic tube based on the 3D model of the orthodontic tube structure.
2. The method of claim 1, further comprising:
determining a radius of curvature of corners of the curved gingival base edge;
wherein generating the 3D model of the orthodontic tube structure comprises generating the curved gingival base edge with corners of the determined radius of curvature.
3. The method of claim 2, wherein determining the radius of curvature for the corners of the curved gingival base edge comprises determining the radius of curvature based on a 3D model of a tooth of the one or more teeth.
4. The method of claim 3, wherein determining the radius of curvature based on the 3D model of the tooth comprises determining the radius of curvature based on a gingival margin of the tooth.
5. The method of claim 2, wherein determining the radius of curvature of the corners of the curved gingival base edge comprises determining the radius of curvature based on an orthodontic prescription.
6. The method of claim 5, wherein the orthodontic prescription comprises an indication of torque, tip, rotation, or a combination thereof.
7. The method of claim 1, wherein a radius of curvature of a corner of the curved gingival base edge is approximately 0.05 mm to 2.0 mm.
8. The method of claim 1, wherein the orthodontic tube structure comprises a curved occlusal edge.
9. The method of claim 1, wherein the orthodontic tube structure comprises an angled hook.
10. The method of claim 9, further comprising:
determining an angle of the angled hook;
wherein generating the 3D model of the orthodontic tube structure comprises generating the angled hook with the determined angle.
11. The method of claim 9, wherein the angled hook is angled between 0 degrees and 90 degrees labially from a face of the orthodontic tube structure.
12. The method of claim 9, wherein the angled hook is angled between 0 degrees and 90 degrees facially from a face of the orthodontic tube structure.
13. The method of claim 9, wherein the angled hook is angled between 0 degrees and 45 degrees from a body of the orthodontic tube structure in a plane of the angled hook.
14. An additively manufactured customized orthodontic tube produced by an additive manufacturing device using a 3D model of an orthodontic tube structure generated using a 3D model of one or more teeth of a patient, the additively manufactured customized orthodontic tube comprising:
a curved gingival base edge, the base edge being curved to approximate a gingival margin of a tooth of the patient.
15. The additively manufactured customized orthodontic tube of claim 14, further comprising a curved occlusal edge.
16. The additively manufactured customized orthodontic tube of claim 14, wherein a curvature of the curved gingival edge is based on a gingival margin of a tooth of the one or more teeth.
17. The additively manufactured customized orthodontic tube of claim 14, wherein a curvature of the curved gingival edge is based on an orthodontic prescription.
18. The additively manufactured customized orthodontic tube of claim 14, wherein a radius of curvature of corners of the curved gingival base edge is approximately 0.05 mm to 2.0 mm.
19. The additively manufactured customized orthodontic tube of claim 14, further comprising an angled hook.
20. The additively manufactured customized orthodontic tube of claim 19, wherein the angled hook is angled relative to a body of the customized orthodontic tube to avoid contact of the angled hook with a portion of the patient's mouth.
21. The additively manufactured customized orthodontic tube of claim 14, wherein the curved gingival base edge comprises a curved edge along a middle third of the gingival base edge of the orthodontic tube.
技术领域：
[0002]An embodiment of present invention relates generally to the manufacturing of ceramic labial/lingual orthodontic tubes for straightening the teeth and correcting malocclusion. More specifically, an embodiment of the invention relates to the methodology of direct manufacture of customized labial/lingual orthodontic tube by using a ceramic slurry-based additive manufacturing (AM) technology.
背景技术：
[0003]Orthodontics has been widely adapted in clinics to correct malocclusion and straighten teeth. The traditional method is to adhere preformed brackets and tubes onto the teeth and run elastic metal wires of round, square, or rectangular cross-sectional shape through the tube slots to provide the driving force. The adaptation of the bracket and tube to the individual tooth is performed by filling the gap between the tooth surface and bracket and tube surface with adhesive. This thereby bonds the brackets and tubes to the tooth such that the bracket and tube slots, when the teeth are moved to their final position, lie in a near flat (depending on manufacturing accuracy) horizontal plane.
发明内容：
[0004]Some embodiments of the present invention provide improved techniques for creating custom lingual or labial ceramic orthodontic tubes, and which provides the capability for in-office fabrication of such tubes.
[0005]Pre-formed edgewise tubes may have no prescription, requiring adjustment of the archwire. Alternatively, the edgewise tubes may have an idealized prescription of angulation, inclination, or in/out variation for specific teeth in what is referred to as a “straight-wire appliance”. Because the tube pad is typically not custom made for an individual patient's tooth, the clinician is responsible for the tube placement, which may introduce a source of error, which commonly increases patient visits and overall treatment time. These tubes are typically off-the-shelf products. A misplacement in bonding a tube to a tooth can be corrected by compensation bends in the wire or by debonding and repositioning of the tube, both of which increase time and cost. Custom metal lingual tubes are currently available that are fabricated at a central location from 3D scans or impressions of the dentition and mailed back to the clinician and transferred to the patient via indirect bonding. Selective laser melting (SLM) is a 3DAM technique that has been used to create custom metal lingual brackets and tubes (for example, see U.S. Pat. No. 8,694,142), but this technique suffers from insufficient resolution and surface finish. While true custom labial tubes have been used, custom positioning of a standard, non-custom tube can be created via indirect bonding which itself has inherent error within the tube itself. Many current true custom labial systems (SURESMILE™ Inc.) rely heavily on putting custom bends in the wire based on a 3D scan rather than creating a true straight-wire appliance. For example, U.S. Pat. No. 8,690,568 provides for a method to weld a metal bracket slot to a stock metal bracket base into a custom position, but does not describe a method for creating a custom bracket base or to create an aesthetic, non-metal bracket. These partially custom metal brackets and tubes (akin to tubes) suffer from inaccuracy in slot position and premature debonding due a stock base that doesn't match the tooth morphology, and are unappealing to older patients who prefer to have non-metal appliances for aesthetic concerns. Ceramic brackets have been commercially available and studied since the 1980s and are a desirable material compared to metal brackets due to their excellent esthetics, resistance to creep, rigidity, biocompatibility, corrosion resistance, stability in the oral environment and non-toxic nature. However, non-customized ceramic tubes have only been available since 2018 as the need for an aesthetic alternative to metal is not as concerning to patients due to their location in the bracket of the mouth. Ceramic brackets and tubes are predominantly manufactured by injection molding, which has manufacturing limitations. For example, it may be difficult or impossible to use injection molding to create undercuts that may enhance a tube's mechanical bond strength to a tooth adhesive.
[0006]Ceramic tubes, unlike metal, do not bend in order to debond but instead the connection between the tube and the bonding material must be broken. Due to the mechanical properties of ceramic and this debond mechanism, there is a higher risk of enamel damage when debonding a tube if the tube does not easily separate from the tooth. In this case a diamond burr is necessary to drill the tube off the tooth which can create sparks, take a long time, and result in a poor patient and provider experience.
[0007]Currently, there are no commercially available ceramic tubes which debond via a controlled fracture along a form of ‘stress concentrator’ designed to force the tube to break at a particular location when pressure is applied. A static shape for the stress concentrator does not provide a consistent debonding experience depending on the thickness (in-out) of the tube and its exact position on the tooth, and thus a custom shape must also be used.
[0008]Currently, no system for creating an esthetic custom lingual or labial ceramic orthodontic tube exists, and no custom bracket and tube system exists that may be fabricated 100% in-office by trained members of a private orthodontic practice. A need arises for more efficient and accurate techniques for creating custom lingual and labial ceramic orthodontic tubes, and more aesthetic labial tubes.
[0009]Some embodiments of the present invention may be used to solve problems occurring in the current manufacturing techniques of straight wire appliance orthodontic tubes. For example, in one embodiment, it may provide a direct manufacturing method of customized lingual/labial tubes by utilizing any number of ceramic slurry-based AM technologies, examples of which may include digital light processing (DLP), laser photopolymerization stereolithography, jet printing (including particle jetting, nanoparticle jetting), layer slurry depositioning (LSD), or laser-induced slip casting. A slurry is defined as inorganic particles dispersed in a liquid, and may be photopolymerizable or may polymerize by other mechanisms. Likewise, similar methods may be used to create metal tubes wherein the inorganic materials in the slurry are metal. Examples of items that may be produced include customized labial/lingual tubes according to individual dental and craniofacial features, which may have a direct tooth-matching fault line/grooves (also referred to as fracture grooves, stress concentrators, or breakaway mechanisms) designed into the tube. Ceramic slurry-based AM may be performed in a device small enough to comfortably fit in a private orthodontic lab and can currently be obtained at a reasonable price, given the market price and in-office volume for non-custom and custom tubes.
[0010]For example, in some embodiments, a method of manufacturing customized ceramic labial/lingual orthodontic tubes by ceramic slurry-based AM may comprise measuring dentition data of a profile of teeth of a patient, based on the dentition data, creating a three dimensional computer-assisted design (3D CAD) model of the patient's teeth using reverse engineering, and saving the 3D CAD model on a computer, designing a 3D CAD tube structure model for a single labial or lingual tube structure, importing data related to the 3D CAD tube structure model into a ceramic slurry-based AM machine, directly producing the tube (green part) in the ceramic slurry-based AM machine by layer manufacturing. Processing the tubes may occur in a sintering and debinding furnace prior to direct use or other post-processing steps related to surface properties.
[0011]The 3D CAD tube structure model may include data representing at least a) the tube pad (base) that has recesses and/or undercuts into the bonding surface of the tube, to contact a particular tooth's surfaces, b) fault grooves (also referred to as fracture grooves, stress concentrators, or breakaway mechanisms) that are matched to the patient's teeth to facilitate debonding, c) slots for positioning according to the orthodontic needs of the patient, d) a tube material, e) the particular tooth's profile, and f) a tube guide to guide 3-dimensional placement of the tube onto the tooth.
[0012]The ceramic slurry-based AM machine may comprise a molding compartment comprising a platform and a plunger to directly produce the tube by layer manufacturing, a material compartment, and an LED light source for digital light processing, or a print-head with at least one dispensing nozzle as used in “jet” printing, wherein the tube is produced by layer manufacturing using slicing software to separate the 3D CAD tube structure model into layers and to get a horizontal section model for each layer so that a shape of each layer produced by the ceramic slurry-based AM machine is consistent with the 3D CAD structure data. The ceramic slurry-based AM machine may comprise a vat adapted to hold the tube during manufacturing, a horizontal build platform adapted to be held at a settable height above the vat bottom, an exposure unit, adapted to be controlled for position selective exposure of a surface on the horizontal build platform with an intensity pattern with predetermined geometry, a control unit, adapted to receive the 3D CAD tube structure model and, using the 3D CAD tube structure model to polymerize in successive exposure steps layers lying one above the other on the build platform, respectively with predetermined geometry, by controlling the exposure unit, and to adjust, after each exposure step for a layer, a relative position of the build platform to the vat bottom, to build up the object successively in the desired form, which results from the sequence of the layer geometries. The exposure unit may further comprise a laser as a light source, a light beam of which successively scans the exposure area by way of a movable mirror controlled by the control unit.
[0013]The ceramic slurry-based AM machine may include a light source that is a laser or LED light source. A light source of the DLP machine may radiate a wavelength between 400 and 500 nm. The DLP machine may include a digital light processing chip as a light modulator. The digital light processing chip may be a micromirror array or an LCD array. Alternatively, the ceramic slurry-based AM machine may use a jet technology whereby a liquid ceramic slurry is jetted onto a build-plate in layers, with or without another jet dispensing non-ceramic support material.
[0014]Measuring dentition data may be performed using a CT scanner, intra-oral scanner, a coordinate measuring machine, a laser scanner, or a structured light digitizer. Measuring dentition data may be performed by conducting 3D scanning on a casted or 3D printed teeth model.
[0015]The light-polymerizable material may be selected from the group consisting of high strength oxides, nitrides and carbides ceramics and metals including but not limited to: Aluminum Oxide (Al2O3), Zirconium Oxide (ZrO2), Alumina-toughened Zirconia (ATZ), Zirconia-toughened alumina (ZTA), Lithium disilicate, Leucite silicate and Silicon Nitride as well as metals such as Stainless Steel 17-4PH or 316L, Titanium (Ti/Ti—Al6-V4), Cobalt Chromium (CoCr), Tungsten and Tungsten Carbide/Cobalt (W or WC/Co), Silicon Carbide (SiC), Molybdenum (Mo) and precious metals (e.g. gold (Au)).
[0016]Directly producing the tube by layer manufacturing may further comprise an apparatus comprising a vat with an at least partially transparent or translucent formed horizontal bottom, into which light polymerizable material can be filled, a horizontal build platform adapted to be held at a settable height above the vat bottom, an exposure unit adapted to be controlled for position and selective exposure of a surface on the build platform with an intensity pattern with predetermined geometry, comprising a light source refined by micromirrors to more precisely control curing, a control unit adapted for polymerizing in successive exposure steps layers lying one above the other on the build platform, controlling the exposure unit so as to selectively expose a photo-reactive slurry in the vat, adjusting, after each exposure for a layer, a relative position of the build platform to the vat bottom, and building up the tube successively in the desired form, resulting from the sequence of the layer geometries. The exposure unit may further comprise a laser as a light source, a light beam of which successively scans the exposure area by way of a movable mirror controlled by the control unit.
[0017]A scanning accuracy may be less than 0.02 mm. A manufacturing accuracy may be from 1 to about 60 μm, and wherein the accuracy may be achieved by using a between layer additive error compensation method that predicts an amount of polymerization shrinkage. Manufactured layers of the tube comprise a material selected from the group consisting of high strength oxides, nitrides and carbides ceramics as well as metal including but not limited to: Aluminum Oxide (Al2O3), Zirconium Oxide (ZrO2), Alumina-toughened Zirconia (ATZ), Zirconia-toughened alumina (ZTA), Lithium disilicate, Leucite silicate and Silicon Nitride as well as metals such as Stainless Steel 17-4PH or 316L, Titanium (Ti/Ti—Al6-V4), Cobalt Chromium (CoCr), Tungsten and Tungsten Carbide/Cobalt (W or WC/Co), Silicon Carbide (SiC), Molybdenum (Mo) and precious metals (e.g. gold (Au)).
[0018]The 3D CAD model may be saved as an .stl file or another 3D vector file. The thickness of the manufactured layers may be from 5 to 100 micrometers (μm), and the machine may use a X-Y pixel resolution from 1-100 μm. Different curing strategies (CSs) and depths of cure (Cd) may be used. The selection of material for producing layers of the tube may be based on different force demands.
[0019]The printed tubes may have a metal insert that contacts the archwire in the slot. The printed tubes may be of a traditional twin design or are modified to be self-ligating or active ligating and are designed to accommodate 0.018 in to 0.022 in archwires in the slot, but slot height may vary from 0.017-0.023 in. A slot position relative to the tooth may be customized by manufacturing a custom base or by manufacturing a custom slot position where a base is unchanged. The smallest length from a tube pad to slot depth may be from 0.2 mm-3 mm depending on the tube offset required and desire to reduce the tube profile for patient comfort. The tube angulation, offsets, torque, and prescription may be determined based on a chosen treatment. The structural properties of the tube (any location) may be altered to facilitate easier debonding of the tube following treatment. A part of the tube may be a pre-formed green ceramic body that functions to decrease the time and complexity of the printed tube.
[0020]The printed tube guides may have a single tube attachment for a single tube. An adhesive material may be used to hold the tube on the ceramic archwire. The adhesive material may be sticky wax. Indirect bonding/custom tube placement may occur via a tray (for example, a silicone based, or vacuum formed tray) that carries the said custom ceramic tubes to the ideal tooth location. The method may further comprise producing a tube guide comprising a rigid ceramic rectangular archwire or other archform that dictates a position of each tube on a tooth in every plane with at least two occlusal/incisal supports adapted to help place tubes via an indirect bonding system. A part of the tube that holds or connects the tube to the tooth surface may be designed based on a surface profile of the tooth.
[0021]The tube may have a color that is matched to a color of a tooth to which the tube is to be attached. The tube may be clear. The tube may have a selected color unrelated to a color of a tooth to which the tube is to be attached.
[0022]In some embodiments, the 3D CAD tube structure model may include data defining at least one slot adapted to receive an archwire, including data defining a compensation angle for walls of the slot to compensate for shrinkage due to over-polymerization and achieve parallel slot walls.
[0023]In some embodiments, the 3D CAD tube structure model may include data defining a contour of a surface of a base of the tube. The contour may be adapted to a shape of a tooth to which the tube is to be bonded. The contour may be further adapted based on at least one of an in/out and offset of the tube, a tip of the slot, and a torque.
[0024]In some embodiments, the 3D CAD tube structure model includes data defining a ridge on a circumferential surface of the tube structure base. The ridge can be positioned at an interface of the tube structure base and the tube structure face. The ridge can be positioned on a gingival edge surface of the tube structure, an occlusal edge surface of the tube structure, or both. The height of the ridge can vary along the mesial/distal axis of the tube structure. A height of the ridge can be from about 0.04 mm to about 1 mm. The height of the gingival ridge can be different than a height of the occlusal ridge. The 3D CAD tube structure model can include data defining a gap in the ridge corresponding to a position of the stress concentrator.
[0025]In some embodiments, the 3D CAD tube structure model includes data defining a chamfer in a base of the tube structure. The chamfer can be positioned at an interface of the tube structure and the tooth. The chamfer can be positioned on a gingival tube/tooth interface, an occlusal tube/tooth interface, or both. The chamfer can be configured to mate with an orthodontic tool. In some embodiments, the 3D CAD tube structure model may include data defining a fracture groove in the base or face (auxiliary slot, or vertical slot) of the tube. The fracture groove may be adapted so as to fracture upon application of a normal force. The normal force may be applied in at least one of a mesial-distal direction, an occlusal-gingival direction, or to any opposite corners. The fracture groove may be adapted to provide predictable fracture of the tube upon application of the normal force, enabling debonding of the tube though a combination of tensile and peeling forces. The combination of tensile and peeling forces may be less than a shear bond strength of a bonded tube. The normal force may be 10-180 Newtons, inclusive.
[0026]The fracture groove may be in a middle vertical third of the tube as defined by the tube dimension or the base dimension if they are not the same. The fracture groove has smoothed edges to avoid trapping intra-oral debris. The fracture groove may include a weakened area including a tooth curved depression occlusal-gingival or mesial-distal direction which may come to a pointed tip. This pointed tip may aid in reliability of the fracture. The fracture groove may match a contour of the tooth for that portion of the tube positioning. The fracture groove may be constant in depth from the tooth surface. The fracture groove may have a depth of 0.10 mm to 1.2 mm, inclusive and may be calculated based on the in-out of the tube. The fracture groove may vary in depth from the tooth surface. The fracture groove may have a variance in depth of up to 50% of the distance from the tooth surface to the deepest part of fracture groove. The width of the fracture groove may be between 0.25 mm and 1.25 mm.
[0027]In some embodiments, the 3D CAD tube structure model may include data defining at least some corners of the tube as being rounded. Both gingival and occlusal corners of the tube may be rounded. The rounded corners of the tube may have a radius of curvature of 0.05 to 2.0 mm, inclusive. The rounding may be symmetric or asymmetric.
[0028]In some embodiments, the 3D CAD tube structure model may include data defining a plurality of retentive structures in a base of the tube. Each retentive structure may be a three-dimensional figure with a positive draft angle greater than 0°. Each retentive structure may be a three-dimensional figure selected from a group of three-dimensional figures including semi-lunar cones, full-circle cones, squares, rectangles, retentive lattices, and or meshes. Each retentive structure may have a cross-section that is generally trapezoidal, and having a neutral plane oriented toward a tooth structure or surface, which is wider than a base plane oriented toward a tube body. Each neutral plane may be flat. Each neutral plane may be parallel to the base plane. At least some neutral planes may not be parallel to the base plane. At least some neutral planes may not be parallel to the base plane such that an overall pattern of the retentive structures is generally contoured to a shape of a tooth surface to which it is to be bonded. At least some neutral planes may be contoured to a shape of a tooth surface to which it is to be bonded.
[0029]In some embodiments, the tube may be adapted to be bonded to the lingual or labial surfaces of a tooth. The labial or lingual tube may be made of Aluminum Oxide (Al2O3), Zirconium Oxide (ZrO2), Alumina-toughened Zirconia (ATZ), Zirconia-toughened alumina (ZTA), Lithium disilicate, Leucite silicate and Silicon Nitride as well as metals such as Stainless Steel 17-4PH or 316L, Titanium (Ti/Ti—Al6-V4), Cobalt Chromium (CoCr), Tungsten and Tungsten Carbide/Cobalt (W or WC/Co), Silicon Carbide (SiC), Molybdenum (Mo) and precious metals (e.g. gold (Au)). The 3D CAD tube structure model may include data defining a mesial-distal or horizontal slot adapted to receive an archwire, a vertical slot adapted to receive at least a portion of the archwire within a middle third of the tube, or both. The vertical slot may be further adapted to accept a digitally designed lingual multiloop wire.
[0030]Some embodiments provide a method of manufacturing customized orthodontic tubes for patients. The method comprises: obtaining a three-dimensional (3D) model of one or more teeth of a patient; generating a 3D model of an orthodontic tube structure using the 3D model of the one or more teeth of the patient, the orthodontic tube structure comprising: a debonding structure that facilitates debonding of an orthodontic tube from a tooth of the patient; and using an additive manufacturing device to produce a customized orthodontic tube based on the 3D model of the orthodontic tube structure.
[0031]In some embodiments, at least a portion of the debonding structure has a customized shape based on a 3D model of at least one of the one or more teeth. In some embodiments, the debonding structure comprises a stress concentrator in a portion of the orthodontic tube structure. In some embodiments, the stress concentrator is shaped such that the customized orthodontic tube fractures when a normal force applied to the stress concentrator. In some embodiments, the stress concentrator runs along an occlusal-gingival direction of the orthodontic tube structure. In some embodiments, the stress concentrator includes a portion with a profile that is substantially triangular cross-section.
[0032]In some embodiments, the debonding structure comprises a ridge in the 3D model of the orthodontic tube structure. In some embodiments, the ridge is proximate an interface of a base of the orthodontic tube structure and a face of the orthodontic tube structure. In some embodiments, a height of the ridge varies along a mesial-distal axis of the orthodontic tube structure.
[0033]Some embodiments provide a customized orthodontic tube produced by an additive manufacturing device using a 3D model of an orthodontic tube structure generated using a 3D model of one or more teeth of a patient, the customized orthodontic tube comprising: a debonding structure that facilitates debonding of the customized orthodontic tube from a tooth of the patient.
[0034]In some embodiments, at least a portion of the debonding structure has a customized shape based on a 3D model of at least one of the one or more teeth. In some embodiments, the debonding structure comprises a stress concentrator in a portion of the customized orthodontic tube. In some embodiments, the customized orthodontic tube fractures in response to application of a normal force to the stress concentrator. In some embodiments, the customized orthodontic tube further comprises: a base; and two portions; wherein: the stress concentrator comprises an approximately V-shaped space between the two portions; and a vertex of the approximately V-shaped space is proximate the base. In some embodiments, each of the two portions comprises a substantially flat wall on a respective side of the approximately V-shaped space.
[0035]In some embodiments, the debonding structure comprises at least one ridge. In some embodiments, the customized orthodontic tube further comprises: a base; and a face perpendicular to the base; wherein the at least one ridge is located, at least in part, proximate an intersection of the base and the face. In some embodiments, the face comprises a slot opening sized for an arch wire to be inserted through the slot. In some embodiments, the customized orthodontic tube comprises two portions separated, at least in part, by a space, and the at least one ridge comprises a first ridge and a second ridge, wherein: a first ridge is located on a first one of the two portions; and a second ridge is located on a second one of the two portions. In some embodiments, the space separating the two portions is a stress concentrator.
[0036]In some embodiments, the customized orthodontic tube further comprises multiple portions each comprising a respective slot extending through the portion. In some embodiments, the slots of the multiple portions are aligned such that arch wire passes through the slots of the multiple portions.
[0037]Some embodiments provide a method of manufacturing customized orthodontic tubes for Patients. The method comprises: obtaining a three-dimensional (3D) model of one or more teeth of a patient; generating a 3D model of an orthodontic tube structure using the 3D model of the one or more teeth of the patient, the orthodontic tube structure comprising: a slot surrounded by a plurality of walls for receiving wire, wherein ends of one or more of the plurality of walls are angled relative to a mesial surface of the orthodontic tube structure; using an additive manufacturing device to produce a customized orthodontic tube based on the 3D model of the orthodontic tube structure.
[0038]In some embodiments, the method further comprises: determining an angle of a main portion the slot based on an orthodontic prescription; wherein generating the 3D model of the orthodontic tube structure comprises generating the slot with the determined angle of the main portion of the slot. In some embodiments, the orthodontic prescription comprises an indication of a desired torque, tip, rotation, or a combination thereof, for an associated tooth of the patient's teeth.
[0039]In some embodiments, the slot comprises: four walls and four corners; and the slot comprises a mortise in each corner of the slot to prevent polymerization of material in the corners of the slot during additive manufacturing of the customized orthodontic tube.
[0040]In some embodiments, the method further comprises: determining a size and shape of the slot based on a size and shape of a wire to be received by the slot; wherein generating the 3D model of the orthodontic tube structure comprises generating the slot with the determined size and shape.
[0041]In some embodiments, generating the 3D model of the orthodontic tube structure comprises: determining a grayscale pattern for at least a portion of the slot, wherein the grayscale pattern indicates a pattern of polymerization to be applied by the additive manufacturing device; and applying the grayscale pattern to the at least the portion of the slot. In some embodiments, the grayscale pattern comprises a plurality of pixels each indicating an amount of material to be polymerized at a respective location in the 3D model of the orthodontic tube structure. In some embodiments, the grayscale pattern comprises a plurality of pixels each indicating whether polymerization is turned on or off at a respective location in the 3D model of the orthodontic tube structure.
[0042]In some embodiments, the orthodontic tube structure comprises a notch through which material flowing through the slot can exit the orthodontic tube structure. In some embodiments, the orthodontic tube structure comprises an interface adjacent to a build plate on which the customized orthodontic tube is produced; and the notch is located, at least in part, at the interface adjacent to the build plate.
[0043]Some embodiments provide a customized orthodontic tube produced by an additive manufacturing device using a 3D model of an orthodontic tube structure generated using a 3D model of one or more teeth of a patient, the customized orthodontic tube comprising: a slot surrounded by a plurality of walls for receiving a wire, wherein ends of one or more of the plurality of walls are angled relative to a mesial surface of the customized orthodontic tube.
[0044]In some embodiments, an angle of a main portion of the slot is based on an orthodontic prescription. In some embodiments, the slot is shaped based on a shape of the wire to be received by the slot. In some embodiments, the customized orthodontic tube further comprises a notch that allows material to flow out of the slot through the notch when the customized orthodontic tube is connected to a base plate. In some embodiments, the customized orthodontic tube further comprises two portions, each having a respective slot extended through the portion. In some embodiments, a slot of each of the two portions includes: a first side at which ends of one or more slot walls are angled; and a second side at which ends of one or more slot walls are not angled. In some embodiments, slots of the two portions are aligned such that an angle of a main portion of a first slot is the same as an angle of a main portion of a second slot.
[0045]According to some embodiments, the slot is shaped to receive an approximately rectangular wire. According to some embodiments, at least some of the plurality of walls are substantially parallel relative to one another. According to some embodiments, the ends of the one or more walls are each angled between approximately 20 to 80 degrees from a mesial face of the customized orthodontic tube.
[0046]Some embodiments provide a method of manufacturing customized orthodontic tubes for Patients. The method comprises: obtaining a three-dimensional (3D) model of one or more teeth of a patient; generating a 3D model of an orthodontic tube structure using the 3D model of the one or more teeth of the patient, the orthodontic tube structure comprising a curved gingival base edge; and using an additive manufacturing device to produce a customized orthodontic tube based on the 3D model of the orthodontic tube structure.
[0047]In some embodiments, the method further comprises: determining a radius of curvature of corners of the curved gingival base edge; wherein generating the 3D model of the orthodontic tube structure comprises generating the curved gingival base edge with corners of the determined radius of curvature. In some embodiments, determining the radius of curvature for the corners of the curved gingival base edge comprises determining the radius of curvature based on a 3D model of a tooth of the one or more teeth. In some embodiments, determining the radius of curvature based on the 3D model of the tooth comprises determining the radius of curvature based on a gingival margin of the tooth. In some embodiments, determining the radius of curvature of the corners of the curved gingival base edge comprises determining the radius of curvature based on an orthodontic prescription.
[0048]In some embodiments, the orthodontic prescription comprises an indication of torque, tip, rotation, or a combination thereof. In some embodiments, a radius of curvature of a corner of the curved gingival base edge is approximately 0.05 mm to 2.0 mm. In some embodiments, the orthodontic tube structure comprises a curved occlusal edge. In some embodiments, the orthodontic tube structure comprises an angled hook.
[0049]In some embodiments, the method further comprises: determining an angle of the angled hook; wherein generating the 3D model of the orthodontic tube structure comprises generating the angled hook with the determined angle. In some embodiments, the angled hook is angled between 0 degrees and 90 degrees labially from a face of the orthodontic tube structure. In some embodiments, the angled hook is angled between 0 degrees and 90 degrees facially from a face of the orthodontic tube structure. In some embodiments, the angled hook is angled between 0 degrees and 45 degrees from a body of the orthodontic tube structure in a plane of the angled hook.
[0050]Some embodiments provide a customized orthodontic tube produced by an additive manufacturing device using a 3D model of an orthodontic tube structure generated using a 3D model of one or more teeth of a patient. The customized orthodontic tube comprises: a curved gingival base edge.
[0051]In some embodiments, the customized orthodontic tube further comprises a curved occlusal edge. In some embodiments, a curvature of the curved gingival edge is based on a gingival margin of a tooth of the one or more teeth. In some embodiments, a curvature of the curved gingival edge is based on an orthodontic prescription. In some embodiments, a radius of
具体实施方式：
[0084]Some embodiments of the present invention provide improved techniques for creating custom lingual or labial orthodontic tubes, and which provides the capability for in-office fabrication of such tubes. A lingual or labial orthodontic tube may also be referred to herein as an “orthodontic tube” or a “tube”.
[0085]The inventors have recognized that conventional orthodontic tubes may not reliably debond from a patient's teeth, and thus are difficult to remove from patient's teeth. As such, conventional orthodontic tubes may require a clinician (e.g., an orthodontist) to apply a large amount of force or otherwise perform significant maneuvering to debond an orthodontic tube from a patient's tooth. This makes treatment more difficult for the clinician while also increasing discomfort for a patient during the treatment.
[0086]Accordingly, the inventors have developed a customized orthodontic tube with a debonding structure that allows the orthodontic tube to reliably debond from a tooth, and techniques of manufacturing the customized orthodontic tube. The debonding structure may allow a clinician to apply an amount of force at a location in an orthodontic tube to reliably debond the orthodontic tube from a patient's tooth. In some embodiments, the debonding structure may include a stress concentrator that causes an orthodontic tube to break as a result of a force applied to a particular location in the orthodontic tube. In some embodiments, the debonding structure may include a ridge that allows a clinician to debond an orthodontic tube by applying force on the ridge (e.g., using pliers).
[0087]The inventors have further developed a customized orthodontic tube with slots shaped to facilitate orthodontic treatment and techniques of manufacturing the customized orthodontic tube. The techniques may shape the slots to facilitate orthodontic treatment. In some embodiments, the slots may include angled or chamfered wall ends that make insertion of wire into the slots easier for a clinician. In some embodiments, the slots may have customized slot angles to provide a desired force for orthodontic treatment. For example, the slot angle of an orthodontic tube may be customized to apply a force based on an orthodontic prescription that indicating desired movement to be applied to a patient's teeth (e.g., torque, tip, rotation, or a combination thereof).
[0088]The inventors have further developed techniques of AM of an orthodontic tube that produce orthodontic tube that more accurately matches dimensions of a 3D model of an orthodontic tube structure. In some embodiments, the techniques determine a grayscale pattern for portions (e.g., pixels) of a slot in a 3D model of an orthodontic tube structure. The grayscale pattern indicates a pattern of polymerization to be applied by an AM device at locations in an orthodontic tube during manufacturing. For example, the grayscale pattern may indicate that polymerization is to be turned off at certain locations and turned on at other locations. In another example, the grayscale pattern may indicate varying intensities of polymerization across portions the slot. The grayscale pattern may result in a manufactured orthodontic tube that more closely matches a 3D model of an orthodontic tube structure used in AM. In some embodiments, the techniques place mortices in corners of a slot in a 3D model of an orthodontic tube structure. The mortices may represent locations where polymerization of an AM device is to be turned off. The mortices in the 3D model of the orthodontic tube structure may reduce roundness in corners of an orthodontic tube produced by AM.
[0089]The inventors have developed an orthodontic tube that facilitates post processing of the orthodontic tube after AM. After an orthodontic tube is manufactured by an AM device, it may be necessary to clean the orthodontic tube. For example, cleaning material may be applied to the orthodontic tube to remove any excess unpolymerized material. Accordingly, the inventors have developed an orthodontic tube that includes a notch to facilitate cleaning of an orthodontic tube. The notch may allow material in a slot of the orthodontic tube to flow out of the notch while the orthodontic tube is attached to a base plate on which it was manufactured by an AM device.
[0090]The inventors have further developed orthodontic tubes and techniques of manufacturing thereof that reduce discomfort of orthodontic tubes in a patient's mouth. In some embodiments, the techniques produce an orthodontic tube with curved gingival and/or occlusal base edges. The curved gingival and/or occlusal base edges may allow placement of an orthodontic tube closer to gums of a patient while reducing discomfort to the patient by aligning more closely with the patient's gum line. In some embodiments, the techniques produce an orthodontic tube with angled hooks so prevent the hooks from contacting portions of a patient's mouth (e.g., gums and/or cheeks) to reduce discomfort for the patient when the orthodontic tube is placed in the patient's mouth.
[0091]An exemplary flowchart of an embodiment of a direct manufacturing process 100 of lingual or labial orthodontic tubes by ceramic slurry-based AM is shown in FIG. 1. The process begins with 102, in which dentition data is measured and the parameters of the tooth profile are analyzed. For example, such measurement may use CT layer scanning a non-contact 3D scanner or an intra-oral scanner directly on the patient's teeth, or may use 3D readings on a teeth model previously cast or 3D printed using a coordinate measuring machine, a laser scanner, or structured light digitizers. The scanning accuracy of such techniques is typically less than 0.02 mm.
[0092]In 104, based on the given dentition data, a 3D CAD model of the measured teeth is constructed based on the dentition data and saved in the computer in a typical file format, such as the stl, Additive manufacturing File (AMF) format or any other 3D vector file. The exterior structure of teeth is complicated, usually including irregular curves. The software may then be used to rearrange the teeth in the model to the desired treatment outcomes that may be based on the long-axis of a tooth.
[0093]The tube pad, which holds or connects the tube to the tooth surface, may be designed specifically according to the tooth surface profile, instead of a generalized gridding pattern. The customized tube can meet individual case demand, such as increased anterior labial crown torque required in certain types of cases. FIG. 2 shows an example of orthodontic tubes connected to a tooth surface, according to some embodiments of the technology described herein. As shown in the example of FIG. 2, for the curve on the tooth surface 206, the designed tube's pad (the tooth side of the tube) is matched to the lingual or labial surface of the tooth, as shown for a lingual tube 202 and labial tube 204. In this example a tube 202 (or 204 herein) having a base surface 208 that is contoured to the shape of tooth 206, such as along a tube/tooth interface 210. The base surface contouring 208 may be configured to match the desired position of tube 202 on the tooth. Any changes in positioning of the tube may require changes in contouring 208. Base 208 may be contoured to the tooth while the tube face and slot 212 may be aligned to a pre-prescribed location that includes variables typically accounted for in an orthodontic tube prescription, including, for example 1) in/out and offset, 2) tip and 3) torque. For example, an in/out position and offset may involve tube thickness and offset relative to a tooth along tube/tooth interface 210. A tip parameter may involve an angulation of slot 212 along a mesio-distal direction. A torque parameter may involve an inclination of slot 212 and/or base 208 relative to a tooth surface so that torque may be applied by an archwire. The tube 300 can accommodate clinical torque values ranging from 0° to −45° and in cases of extreme torque, the tube may adjust internally while maintaining the same base geometry.
[0094]Continuing within 106, additional information, such as the desired torque, offset, angulation of select tubes and occlusal/incisal coverage for placement guide is entered.
[0095]In 108, the tube (or tubes) is designed by the software based on the input 3D CAD model of the measured teeth, the model of the desired treatment outcomes, and the input additional information. The output of the design process may be a 3D CAD model. Such a 3D CAD model may be designed for a single lingual/labial tube structure, including the tube guide and tube pad in contact with teeth surface, as well as the slots for the ideal position according to the orthodontia requirement, ceramic tube material, and tooth profile.
[0096]The pad (bonding pad) of the tube may be less than 0.4 mm thick from the tooth. The tube placement guide may be placed occlusally/incisally to guide the correct placement of the tube on the tooth. Examples of raw materials of the tubes may include powder of high strength oxide ceramics such as Aluminum Oxide (Al2O3) and Zirconium Oxide (ZrO2), or other high strength ceramic compositions or metals.
[0097]3D CAD tube structure models are processed to generate manufacturing control data for use by the production equipment. For example, where the ceramic slurry-based AM equipment is used to produce the tubes, the software slices the 3D CAD tube structure models to separate it into thin layers and get the horizontal section model for each layer. Based on this section model, the DLP equipment can directly produce ceramic tubes, ensuring the shape of each layer is consistent with the 3D CAD structure data. For example, the thickness of such layers may be about 20 μm to about 50 μm (micrometers or microns) with a manufacturing accuracy of about 1 μm to about 10 μm by using between-layer additive error compensation.
[0098]Returning to 108 of FIG. 1, the 3D CAD tube structure model is transmitted to or imported into a 3D production machine, such as a ceramic slurry-based AM machine and the ceramic tubes are produced.
[0099]DLP is another ceramic additive manufacturing (AM) process that works by stacking layers of a photocurable resin with a ceramic oxides such as Aluminum Oxide (Al2O3) or Zirconium Oxide (ZrO2), Nitrides or Silicates solid loading, and followed by a thermal debinding and sintering step. The higher resolution of this process is made possible by the LED light's digital mirror device (DMD) chip and optics used. (Stereo-)Lithography-based ceramic manufacturing (LCM) has improved this process making it more accurate with higher resolution (40 m) and rigidity. The LCM process involves the selective curing of a photosensitive resin containing homogeneously dispersed oxide or glass ceramic particles that can be fabricated at very high resolution due to imaging systems which enable the transfer of layer information by means of ever-improving LED technology, though a laser may also be used for photopolymerization.
[0100]The base of the tube may be adhered to the tooth surface and the tube slot may be matched to the archwire. According to requirements of mechanical properties, different composition of material may be required for the layers during the DLP manufacturing process. After being built up and processed, the tubes may have a gradient and better performance.
[0101]In 110, post-processing may then be applied. For example, a thermal treatment (for binder burnout) and a sintering process may be applied to achieve optimal or improved ceramic density. For example, the debinding and sintering phase may include removing the green tube from the device, exposing the blank to a furnace to decompose the polymerized binder (debinding), and sintering of the ceramic material.
[0102]In another example, a cleaning or washing treatment may need to be performed to remove all uncured or excess material. The cleaning or washing treatment can be performed when the tube is connected to the build plate, prior to debinding and sintering. In order to accommodate such a process, the tube 300 in FIG. 3A and 400 in FIG. 4A may have a small notch 408 on the mesial side to allow for flow of material (e.g., a cleaning fluid or air) out of the slot during manufacturing, while still allowing sufficient expression of wire torque, as depicted in FIG. 4.
[0103]The notch 408 may have a width between 0.1 and 1.5 mm and a height of 0.1 to 1 mm. The notch 408 may extend from any outer face of the tube through the slot. As shown in FIG. 3, the mesial side of the face of the tube includes three edges flat or substantially flat and configured to be releasably connected to the build plate and a fourth edge (i.e., notch 408) manufactured in the buccal surface of the tube. The notch 408 defined in the buccal surface of the tube can be trapezoidal, substantially trapezoidal, square, substantially square, rectangular, substantially rectangular, substantially, elliptical or substantially elliptical in shape. For a trapezoidal or substantially trapezoidal shape, the nonparallel sides of the notch 408 can have a stepped profile.
[0104]The ratio of the notch 408 to the slot width can be between 25% and 200%. In some embodiments, the ratio is about 25%, 50%, 75%, 100%, 125%, 150% or 200%. For example, the parallel side can be about 100% of the slot width, and the non-parallel sides can be about 25% or 50%.
[0105]FIG. 18 shows an example orthodontic tube 1800 on a base plate 1804, according to some embodiments of the technology described herein. For example, the orthodontic tube 1800 may be obtained by AM using a 3D model of an orthodontic tube structure. The orthodontic tube 1800 may have been produced by an AM device in a sequence of layers beginning from a layer closest to the base plate 1804 as indicated by the “Print direction” arrow in FIG. 18. As shown in FIG. 18, the orthodontic tube 1800 includes a notch 1802 in a location in the orthodontic tube 1800 adjacent the build play 1804. The notch 1802 may allow material in the slot 1806 to flow out of the orthodontic tube 1800. For example, after manufacturing, the orthodontic tube 1800 may be attached to the base plate 1804. Material (e.g., cleaning fluid, air, and/or other material) may be applied to the orthodontic tube 1800. The notch 1802 may provide an opening through which the material can exit the slot 1806.
[0106]Furthermore, the tube surface may also be processed based on clinical demand.
[0107]At 112, the tube is ready to be placed.
[0108]Typically, the thickness of the tube pad may be less than 1 mm for lingual tubes and less than 1.5 for labial tubes. Suitable manufacturing materials may include high strength oxides, nitrides and carbides ceramics and metals including but not limited to: Aluminum Oxide (Al2O3), Zirconium Oxide (ZrO2), Alumina-toughened Zirconia (ATZ), Zirconia-toughened alumina (ZTA), Lithium disilicate, Leucite silicate and Silicon Nitride as well as metals such as Stainless Steel 17-4PH or 316L, Titanium (Ti/Ti—Al6-V4), Cobalt Chromium (CoCr), Tungsten and Tungsten Carbide/Cobalt (W or WC/Co), Silicon Carbide (SiC), Molybdenum (Mo) and precious metals (e.g. gold (Au)). The tube pad may be adhered to the tooth surface with well-known dental adhesives. The tube slot may be matched to the archwire, which may be straight or custom bent. Depending upon the manufacturing process used, different ceramics or composition of powder may be required for the layers. For example, if a selective laser melting manufacturing process is used, an LED light source may be used for the selective curing of a photosensitive resin containing the oxide or glass ceramic particles. Different layers may use different ceramics or compositions of powder.
[0109]End views of an exemplary printed tube 300 are shown in FIG. 3A (mesial view) and 3b (distal view). In FIG. 3a, the base 306 of the tube is shown to the right (buccal side of the tube) and the face 304 of the tube is shown to the left (lingual side of the tube). Pad 308 is the portion that comes into contact with the tooth, and face 304 includes a first tube body 316 defining a first slot 301, which in some embodiments may be a mesial-distal slot adapted to receive an archwire for applying force to a tooth. The tube 300 may have an occlusal-gingival span between 1.4 mm and 5 mm with a mesial distal span between 2 mm and 8 mm. Tube 300 has filleted edges 312 with radii between 0.05 mm and 1 mm to prevent irritation of cheek or gingival tissue. The filleted edges 312 can be formed on the base 306 and/or the first tube body 316. First tube body 316 can include a hook 320.
[0110]The slot 301 may have desired slot wall position 302 and a compensation angle 303 for the walls of slot 301, which may be utilized to counteract shrinkage due to over-polymerization and achieve parallel slot walls 302 of a desired dimension. In some embodiments, slot 301 may be a mesial-distal slot adapted to receive an archwire for applying force to a tooth. Slot 301 may be initially manufactured with a “dovetail” cross-section including compensation angle 303, so that the finished tube may achieve parallel slot walls of a desired dimension, as shown by desired slot wall position 302.
[0111]In some embodiments, the dovetail includes mortises 324 defined at each corner of the slot 301. The slot 324 may comprise four walls and four corners. The slot may comprise a mortise in each corner of the slot. A mortise may indicate an area in the 3D model of the orthodontic tube structure where an AM device is to stop polymerization of material. A mortise may thus prevent polymerization of material in corners of a slot during AM of an orthodontic tube. In some embodiments, polymerization locations in a 3D model may be designated by pixels. In such embodiments, an AM device may stop polymerization of material at a pixel corresponding to a mortise in a 3D model. For example, mortises 324 can be formed by turning off pixels of a digital micromirror device in a DLP system so that material is not polymerized at the pixel location. The mortise may reduce over-polymerization of material and, as a result, cause an orthodontic tube produced by AM to have greater precision. The corners of a slot may be less rounded as a result of the mortises.
[0112]In some embodiments, the slot 301 may be sized and shaped based on a size and shape of a wire to be received by the slot 301. A 3D model of an orthodontic tube structure may be generated with a slot of the size and shape. For example, the slot 301 on the tube may have high accuracy in size, shape, and angle, and may have low thickness and is designed to accommodate a rectangular wire when completely filled. In some embodiments, slot 301 may be manufactured to any desired size and shape. In some embodiments, slot 301 is manufactured with a greater depth than height or width. In some embodiments, slot heights may vary between 0.016 and 0.024 inches while width may be between 0.020 and 0.035 inches.
[0113]In some embodiments, the mesial and distal ends of the slot may be chamfered 310 to allow for easier insertion of an orthodontic wire. In some embodiments, the angle of the chamfer 310 may be between 20° and 80° from the mesial face. A chamfered slot may comprise a slot surrounded by walls with ends of the walls angled relative to a mesial surface of the tube. In some embodiments, a chamfered slot may facilitate insertion of wire into the slot. A chamfered slot may reduce force opposing insertion of a wire through the slot. In some embodiments, an end of one wall of a slot may be chamfered at a different angle than an end of another wall of a slot. In some embodiments, ends of all the walls of the slot may be approximately the same.
[0114]In some embodiments, the base 306 of the tube may have different height because of the selected material or desired orthodontic result. Likewise, the pad 308 of the tube may highly match the tooth surface and maximize the tooth contact surface. This may allow for more accurate tube placement by the clinician and better bond approximation to the tooth. Also, because each slot has its own position and shape to cooperate with the archwire, twisting error may be minimized and improved orthodontic result may be actualized. In a number of embodiments, these features may be manufactured as one piece and that the customization of the slot relative to the tooth may be a function of the slot changing position or the tube base moving. In many embodiments, no machining of the features is required to produce a suitable tube.
[0115]In some embodiments, a mesial surface of a tube 300 includes a pad 308 and a first tube body 316 connected to pad 308. The first tube body 316 defines a slot 301, chamfers 310 defined in the gingival, lingual and occlusal edges of the mesial surface, and a notch 408 formed in the buccal edge of the mesial surface. Pad 308 is configured to be a negative of the tooth surface. Chamfers 310 extend at an inward angle from the edges to the slot wall. Mortises 324 are formed at the intersections of adjacent slot walls. Chamfers are formed by one or more edge surfaces of the notch 408 extending at an inward angle to the slot wall. In the embodiment shown in FIG. 3A, the notch edge opposing the mesial surface is chamfered and extends at inward angle to the slot wall and the nonparallel side edges of the notch 308 extend inward from the mesial surface to the notch edge opposing the mesial surface. Hook 320 is connected to the first tube body 316 at the intersection of the gingival and buccal surfaces of the first tube body 316. In some embodiments, hook 320 can be formed on the buccal surface.
[0116]As depicted on the tube 400 face in FIG. 4A, the tube 400 may have a notation 410 imprinted in the tube to denote which tooth it should be placed on. This notation 410 may be on any surface of the tube and may have a width between 0.5 and 4 mm, and a height range from 0.5 to 4 mm. The notation's depth may be up to 1 mm. This notation 410 may include any form of number, letter, character or polygon or combination therein. In a variation of the design the notation may be raised/embossed from the tube's surface.
[0117]Tubes 400 may further include an attachment such as a hook 404 that provides the capability to use additional delivery systems such as elastomers, springs or other attachments that create vectors of force. In a number of embodiments, these features may be manufactured as one piece, protruding from any pre-designed area to create the proper force vectors desired. Hook 404 can be a curved hook, a straight hook or a ball hook. The hook 404 may have a configurable, custom angle to meet the patient's demands, the doctor's prescription and help to avoid irritation of the gums or of the cheek. FIG. 4A depicts this configurability via a plane 405 of the hook 404 which divides the hook into symmetrical halves.
[0118]In some embodiments, the hook 404 may be angled. For example, the hook 404 may be angled to avoid contact of the hook 404 with a portion of a patient's mouth (e.g., cheek and/or gums) when the orthodontic tube is placed in the patient's mouth. A system generating a 3D model of an orthodontic tube structure may be configured to determine an angle of the hook 404, and generate the 3D model of the orthodontic tube structure to include a hook of the determined angle. In some embodiments, the plane 405 of the hook can be angled between 90° labially and 30° lingually from the face of the tube 400 and can be angled up to 45° in either direction from the direction of the slot. The end of the hook 404 can be angled up to 45° away from the body of the tube 400 in the plane 405 of the hook. Although tubes 300 and 400 are shown with hooks, tubes may be formed without hooks.
[0119]Tube 400 includes a base 414 and a face 418. Base 414 includes a pad surface 422, a gingival edge 426, an occlusal edge 430, a mesial edge 434, and a distal edge 438. The face 414 defines a slot extending therethrough. The face 418 includes a split tube body including a first tube body 442 defining a first slot extending therethrough and a second tube body 446 defining a second slot extending therethrough. Pad 422 is configured to be a negative of the tooth surface. Pad 422 includes retention features as further described with reference to FIGS. 9 and 10. Tubes 400 may also include a cutout 406 behind the slot on the distal end to accommodate attachment or retention of elastomerics, ligature ties, springs or other attachments that create vectors of force. The cutout 406 can be defined between the base and the tube body (e.g., tube body 316 or second tube body 446). The cutout 406 may have a mesial-distal span between 0.1 mm to 1 mm and a labial-lingual dimension between 0.2 mm and 1.5 mm. The cutout 406 can run the occlusal-gingival range of the tube, or be formed along only a portion of the range to, for example, form a rounded end.
[0120]In some embodiments, a nub or protrusion is formed on the distal end of the second tube body 446 to assist with attaching or retaining elastomerics, ligature ties, springs or other attachments.
[0121]As shown in FIG. 4, tube 400 includes two separate cuts made along the central line of the tube running occlusal/gingivally, which will allow the tube to reliably fracture and debond when mesial/distal pressure is applied. The first 401 is cut along the base, and includes a custom contoured polygon that matches the tooth shape which is consistently cut to a depth of up to 0.3 mm from the tooth surface. This polygon has a width greater than 0.1 mm and up 75% of the tube width. The second 402 is the stress concentrator cut from the front of the tube. This second cut shape has smoothed edges to avoid trapping intro-oral debris and may be angled between 0° and 45° towards the mesial face of the tube. This shape comes to a peak in order to provide for consistent fracturing at the desired location. Depending on the specifics of the tooth morphology, the tube prescription, and the desired strength, the cut 403 can be started anywhere from 0.1 mm to 1.2 mm from the tooth and extend the remainder of the tube structure. This cut can have a final width which can range from 5% to 50% of the tube width. The curve of the cut 403 of the shape in the gingival/occlusal direction perfectly matches the curvature of the tooth along the same line. This shape is created by a combination of thickening and Boolean operations based on the distance field of the tooth, and its relationship with the tube. The specifics of the location and thickness of the shape are determined by calculating the in-out of the tube, and using this value in algorithms determined through experimental testing in order to provide the optimal tube strength.
[0122]As described herein, in some embodiments, an orthodontic tube may include a debonding structure comprising a stress concentrator. In some embodiments, the debonding structure may be customized based on a 3D model of a patient's tooth. The stress concentrator may be shaped such that the orthodontic tube fractures in response to a force applied to the stress concentrator. For example, the stress concentrator may fracture in response to a normal force of 35 to 40 Newtons. In some embodiments, the stress concentrator may run along an occlusal-gingival direction of an orthodontic tube. In some embodiments, the stress concentrator may include a portion that has a substantially triangular cross-section.
[0123]FIG. 19 shows an example orthodontic tube 1900 with a stress concentrator 1902, according to some embodiments of the technology described herein. As shown in FIG. 19, the stress concentrator 1902 has a tip at a distance 1904 from a tooth surface. The stress concentrator 1902 then extends into an approximate V-shape from the tip. In the example of FIG. 19, a normal force applied on both sides of the stress concentrator 1902 may cause the orthodontic tube 1902 to break, and thus debond from a patient's tooth. In some embodiments, a distance over which the stress concentrator 1902 widens may be determined based on a desired a size of any flat overhangs. In some embodiments, a maximum width of the stress concentrator 1902 may be determined based on a desired steepness of walls of the stress concentrator 1902.
[0124]As shown in FIG. 4, in some embodiments, the gingival corners 407 of tube 400 are rounded to account for the keratinized/attached gingiva, which can interfere with the bonding surface. The roundness and radius of these corners may be changed from patient to patient, and within a case, from tooth to tooth. In some embodiments, a radius of curvature for gingival corners may be determined based on a 3D model of a patient's tooth. In some embodiments, the roundness and radius, and/or placement relative to the gingival margin and/or occlusal edge of the teeth is determined by the patient's prescription and/or based on a doctor's preference to affect a smile arc. Tubes with custom formed edges can be placed closer to the gingival margin or the occlusal edge than can be a stock tube with a stock base. In some embodiments, a radius of curvature of rounded gingival corners 407 may be in a range of 0.05 to 2.0 mm, inclusive. FIG. 4C shows tube 400′ having a gingival edge 450 curved to approximate the gingival margin 454 of a patient's tooth 458.
[0125]As illustrated in FIG. 4D, in some embodiments, an occlusal edge of an orthodontic tube can be curved or rounded. FIG. 4D shows tube 400″ having an occlusal edge 462 curved to approximate the occlusal surface 466 of a patient's tooth. The radius of curvature of the occlusal edge may be customized for a patient and/or for a tooth. In some embodiments, a radius of curvature for an occlusal edge may be determined based on a 3D model of a patient's tooth. IN some embodiments, the radius of curvature and/or placement relative to an occlusal edge of the tooth may be determined by a patient's orthodontic prescription and/or a doctor's preference to affect a smile arc. Tubes with a curved occlusal edge may be placed closer to an occlusal edge than stock tubes. In some embodiments, a radius of curvature of a curved gingival edge may be in a range of 0.05 to 2.0 mm, inclusive.
[0126]In some embodiments, an orthodontic tube may include a gingival edge curved to approximate the gingival margin of a patient's tooth and an occlusal edge curved to approximate the occlusal surface of the patient's tooth.
[0127]An example of an orthodontic tube 500 is shown in FIG. 5, as viewed from the face of tube 500. In this example, the middle third 502 as defined by the base or overall dimension and the middle third 504 as defined by the dimension of the area of the tube 500 with the slot, are indicated. A fracture groove 508 may be manufactured within the middle vertical third (502 or 504) of the ceramic tube 500.
[0128]An example of an orthodontic tube 600 is shown in FIG. 6, in a cross-sectional view. In the example shown in FIG. 6, a fracture groove 602, horizontal (mesial-distal) slot 604, and auxiliary slot 606 are shown. Fracture groove 602 may include a weakened area including a tooth curved depression (groove) in the tube base 608 running vertically (in the occlusal-gingival direction) within the middle third of tube 600. Fracture groove 602 may match the contour of the tooth for that portion of the tube positioning. Fracture groove 602 may align with the vertical midline of the tube or base and/or deepest portion of auxiliary slot 606. The tube area between these features may form the weakened area of tube 600.
[0129]In some embodiments, fracture groove 602 may be constant in depth from the tooth surface, as shown in FIG. 6. In some embodiments, constant depth fracture groove 602 may be a nominal or predetermined depth for some or all tubes for a patient. For example, groove depths 610, 612, and 614 may all be the same predetermined depth “X”. Such nominal or predetermined depth may be in a range of, for example, 0.10 mm to 1.2 mm, inclusive. In some embodiments, constant depth fracture groove 602 may be a depth that is different for some or for each tube and may be based on the in-out of the tube. For example, a distance from the tooth surface to the deepest part of fracture groove 602 may differ for different tubes.
[0130]An example of an orthodontic tube 700 is shown in FIG. 7, in a cross-sectional view. In some embodiments, fracture groove 702 may be variable in depth from the tooth surface, as shown in FIG. 7. In some embodiments in which fracture groove 702 is variable, the variance