Technique for fastening models using ball plungers

Abstract

This disclosure describes a technique for securing thermoformed models, including a locator plate for receiving and securing an individually unique dental model having a polygonal cutout, the locator plate having at least one ball plunger (108) positioned within a raised pentagon (102), the at least one ball plunger having a cylinder, a spring, and a ball extending partially outside the cylinder. This disclosure also includes a system and method for thermoforming orthodontic aligners.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 428,967, entitled "Techniques for Securing Models Using a Ball Plunger," filed November 30, 2022, the contents of which are incorporated herein in their entirety.

[0002] The present technology relates to manufacturing techniques for dental appliances. More specifically, the present technology relates to techniques for fixing models by using ball plunger plates. [Background technology]

[0003] Orthodontic aligners are appliances intended to make a series of individual tooth position corrections aimed at properly aligning teeth. Aligners are comparable to having brackets and wire appliances for orthodontic treatment, but they offer many advantages. For example, aligners are often transparent or translucent, comfortable to wear, removable for cleaning, and allow patients to eat what they want. Aligner manufacturing traditionally begins with generating a digital model of the patient's teeth, either by scanning them or by making a dental impression of the patient's teeth and then scanning that impression. Once a digital model of the patient's teeth is obtained, a physical dental model can be fabricated (e.g., using 3D printing) to provide a positive model of the teeth, also known as a dental arch.

[0004] When using an intraoral scanning device (an IOS device) to scan a patient's teeth, custom software allows for the import of a 3D computer-aided design (CAD) representation, which allows the operator to move each tooth with specific, individual movements to achieve the final arch of aligned teeth.

[0005] The 3D printed arch model is washed and then allowed to dry, after which a polymer is thermoformed over the top of the 3D printed arch model.

[0006] The thermoformed part is then laser marked with part identification information, and the laser-marked thermoformed part is then cut by one of several methods so that the aligner to be provided to the customer can be separated from the excess aligner material.

[0007] The aligners are then polished in a part-tumbling process to remove burrs and sharp edges. The aligners are inspected, then bagged, sealed, and shipped to the customer's orthodontist or directly to the patient.

[0008] Previous thermoforming designs have had issues with reliably positioning the 3D-printed arch model to press-form the heated plastic film with minimal added material. In addition to creating excess material, these designs did not always accurately hold the model. Current locating mechanism plates on thermoforming models have low robustness in fit, orientation, and position. Specifically, if the attached model is too loose, it will rotate and move, or if it is too tight, the model will not fit properly on the plate or substrate. This results in numerous process steps and repeated refinements. Summary of the Invention

[0009] The present technology solves the above problem by using a locator plate with a raised polygon feature and one or more springs / elastic / active elements with a defined force that pretension the mounting geometry.

[0010] The present technique uses one or more defined contact areas to ensure a defined position and orientation, and one or more defined gaps to allow positioning and orientation according to the contact areas, thereby ensuring a proper fit, correct position, and orientation of the dental model on the base plate.

[0011] Additional benefits of the technology include the robustness to produce thousands of clear aligners per day while reducing thermoforming issues and improving accuracy over competitors' thermoforming and cutting / separation processes.

[0012] This technique also saves costs and time in centralized production, reduces aligner rework, manual correction / refinements, and scrap rates in clear aligner manufacturing, and therefore improves the accuracy, reliability, and scalability of automated aligner manufacturing.

[0013] In one embodiment, the present technology is directed to a locator plate for receiving and securing an individually unique dental model including a raised polygon extending from a surface of the locator plate, having a rectangular base and a triangular top, and at least one ball plunger positioned within the raised pentagon.

[0014] The at least one ball plunger may have a cylindrical body, a spring, and a ball extending partially outside the cylindrical body.

[0015] A portion of the ball that extends partially outside the cylindrical body of the ball plunger may extend from the rectangular base of the raised pentagon and away from the apex of the triangular top of the raised pentagon.

[0016] In some embodiments, the raised polygon is a pentagon with a rectangular base and a triangular top.

[0017] In some embodiments, the raised pentagon is chamfered.

[0018] In some embodiments, the ball is partially within the cylindrical body and engages the spring to move along the longitudinal axis of the cylindrical body.

[0019] In some embodiments, the locator plate includes raised letters spaced apart from the raised pentagon.

[0020] In some embodiments, the locator plate has a dental model attached to the raised pentagon to form the dental aligner, and the ball plunger engages a portion of the dental model to secure the dental model to the locator plate.

[0021] In some embodiments, the polymer sheet is stretched over the dental model.

[0022] In some embodiments, the at least one ball plunger includes a pair of ball plungers positioned within a raised pentagon.

[0023] In an alternative embodiment, the present technology is directed to a method for thermoforming a dental aligner, the method steps including: printing a 3D dental model including a positive model of a dental arch and 3D-printed locator tabs positioned within the dental arch; providing a locator plate having a raised polygon extending from a surface of the locator plate, the raised polygon including at least one ball plunger having a ball extending partially away from the surface of the raised polygon; securing the 3D dental model to the locator plate by positioning the raised polygon within the polygon cutout such that the at least one ball plunger engages the polygon cutout; and thermoforming a polymer sheet over the 3D dental model secured to the locator plate.

[0024] In some embodiments, printing the 3D dental model includes printing edges of a polygonal cutout within the 3D printed locator tab.

[0025] In some embodiments, the raised polygon of the locator plate has an apex directed toward the incisal edge of the dental arch, which apex indicates the proper orientation of the 3D dental model relative to the raised polygon of the locator plate.

[0026] In some embodiments, the raised polygon of the locator plate and the polygonal cutout in the 3D printed locator tab are pentagonal.

[0027] In some embodiments, the pentagonal raised polygon includes a rectangular portion and a triangular portion, and when a vertex of the triangular portion is removed, a gap occurs between the vertex of the triangular portion and the 3D dental model.

[0028] In some embodiments, the 3D dental model is fixed to a locator plate, with a defined gap between three sides of the rectangular portion of the pentagonal raised polygon and the polygonal cutout in the 3D printed locator tab.

[0029] In some embodiments, the at least one ball plunger includes a pair of ball plungers positioned within a raised pentagon.

[0030] In one embodiment, the present technology is directed to a system for thermoforming an orthodontic aligner having a locator plate with a raised polygon extending from a surface of the locator plate using at least one ball plunger positioned within the raised pentagon. The at least one ball plunger has a cylindrical body, a spring, and a ball extending partially outside the cylindrical body. The system further includes a 3D dental model including a positive model of a dental arch and a 3D-printed locator tab positioned within the dental arch. The 3D dental model defines edges of a polygonal cutout in the 3D-printed locator tab. The 3D dental model mates with the locator plate by positioning the raised polygon within the polygonal cutout and engaging the ball of the ball plunger with a portion of the polygonal cutout. The system may also include a heat source for thermoforming a polymer sheet over the 3D dental model once secured to the locator plate.

[0031] In some embodiments, the 3D printed locator tab includes cutout or raised letters positioned along one or more edges of the polygonal cutout.

[0032] In some embodiments, the system further includes a camera for viewing and identifying cut-out or raised characters positioned along one or more edges of the polygonal cut-out.

[0033] In some embodiments, the locator plate further defines a plurality of channels in fluid communication with a vacuum pump for generating a vacuum within the locator plate.

[0034] In some embodiments, the locator plate has a modular design that allows the raised polygon to be secured to the locator plate and the raised polygon to be removed from the locator plate.

[0035] In some embodiments, the locator plate also includes a removable active insert including at least one ball plunger positioned within the raised polygon and a bottom ball plunger extending from a surface of the removable active insert opposite the raised polygon.

[0036] The present technology will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0037] [Figure 1] FIG. 1 shows a top view of a locator plate having a raised chamfered pentagon with one ball plunger. [Figure 2] A top view of the locator plate with two spring plungers and a raised chamfered pentagon is shown. [Figure 3] A 3D perspective view of a ball plunger is shown. [Figure 4]Shows a top-down, angled 3D view of the raised pentagon, locator pin, three locator cones, and single ball plunger, along with the lettering on the locator plate. [Figure 5] A 3D view of the locator plate seen from below at an angle is shown. [Figure 6] (A) shows a top perspective view of a dual spring plunger with threaded holes used to mount the mechanism to a large base plate. (B) shows a top perspective view of a mono spring plunger with threaded holes used to mount the mechanism to a large base plate. [Figure 7] (A) shows a top perspective view of a circular locator plate with a spring plunger design that seats flush with the circular plate. (B) shows a side view of the circular locator plate. [Figure 8] FIG. 10 shows a top view of the raised pentagonal and cylindrical locator pins of the locator plate. [Figure 9A] FIG. 10 shows a perspective view illustrating the attachment of the location mechanism to the base plate. [Figure 9B] FIG. 9B is an exploded view of the elements shown in FIG. 9A. [Figure 10A] 1 shows a flow chart of an exemplary method embodiment of a thermoforming technique. [Figure 10B] 10 shows another flow chart of an exemplary method embodiment of a thermoforming technique. [Figure 11] 10 shows a top view of an alternative embodiment of a raised pentagon and ball plunger system where the active element (ball plunger) is separated from the mold as a retractable insert. [Figure 12] 1A-C show different perspective views of a retractable active element insert, including a top perspective view (A), a side perspective view (B), and a bottom perspective view (C). [Figure 13] 1A and 1B show side perspective views of a retractable active element insert and mold. In A, the downward arrow indicates the direction of force applied to reach the insert's zero (final) position. In B, the retractable active element insert is in the zero (final) position. [Figure 14]FIG. 1 shows a side perspective view of polymer / thermoplastic aligner material thermoformed onto a dental model. DETAILED DESCRIPTION OF THE INVENTION

[0038] The present technology includes a locator plate for receiving and securing an individually unique dental model having a raised polygonal cutout with one or more ball plungers positioned within the raised polygon, at least one of the ball plungers having a cylindrical body, a spring, and a ball extending partially outside the cylindrical body to improve securement of the thermoformed model. The present technology also includes a system for thermoforming a dental aligner and a method for thermoforming a dental aligner. While many embodiments described herein relate to securing a model during the thermoforming process, the present technology may also be used to secure a model during other aligner manufacturing processes, such as trimming of aligner material.

[0039] The technology also allows for easy visualization of additional manufacturing information, if desired. The technology is highly flexible and advantageously presents manufacturing information in a manner that is optimal for character recognition, while using less material than competing designs.

[0040] The raised polygon can be a pentagon with a rectangular base and a triangular top. Surprisingly, the raised pentagon shape is compact enough to fit inside most human dental arches, robust enough not to be damaged or broken during processing, easy to manufacture, provides fast product orientation, is easy to fit, and has sufficient surface area to prevent part rotation. In particular, the pointed ends of the pentagon make it easy to align. The shape allows for an anterior-to-posterior loading motion that is ergonomic and self-aligning. The flat surfaces of the shape prevent 3D arch rotation. Furthermore, the ball plunger design applies force to the dental model, which advantageously eliminates any gap in the contact area between the dental model and the raised pentagon.

[0041] In one example, the present technology is directed to a locator plate for receiving and securing an individually unique dental model such as those shown in FIGS. 1, 4, 5, 7, and 9.

[0042] In some examples, as shown in Figures 1, 2, 4, 6, 7, and 9, the locator plate has a raised polygon, such as a pentagon, that extends from the surface of the locator plate and has a rectangular base and an isosceles triangular top, and a locator pin. In some examples, the raised pentagon is located at the center of the locator plate. In some examples, the locator pin is spaced from the raised pentagon, and the locator pin extends from the surface of the locator plate.

[0043] In some examples, as shown in Figures 1, 4, and 7, the locator plate further includes a first locator cone, a second locator cone, and a third locator cone spaced apart from the raised pentagon in a triangular arrangement.

[0044] In some examples, at least one edge of the raised pentagon is chamfered, as shown in Figures 1, 2, 4-7, and 9. The chamfered edge of the raised pentagon can help the dental model fit more easily into place.

[0045] In some examples, as shown in Figure 4, the locator plate has raised letters spaced apart from the raised pentagon. The raised letters may include a plate identifier. Also, as shown in Figure 4, the tab area of ​​the dental model that defines the cutout portion may also include raised or cutout letters. The letters on the model tab may include a product identifier, case identifier, batch identifier, or another type of code used in downstream processing and manufacturing steps during the aligner manufacturing process.

[0046] In some instances, the locator plate further includes a dental model attached to the raised pentagon to form a dental aligner as shown in Figure 8. In some instances, the locator plate further includes a polymer sheet stretched over the dental model (not shown).

[0047] Specifically, FIG. 1 shows a top view of an exemplary locator plate having a locating feature 102 attached to a base plate 101 that can be screwed to the plate via mounting holes 104. The locating feature 102 includes a raised chamfered pentagon 103 with a rectangular base and an isosceles triangular top shape, and locator pins 105. After trying various shapes, a pentagon with a rectangular base and an isosceles triangular top demonstrated the best fit and alignment accuracy when mating the dental model with the locator plate. The pin locating feature 105 feature also assists in identifying and positioning the dental model to ensure excellent alignment. The pin features are spaced from the raised pentagon and are not limited in number, size, or location on the locator plate.

[0048] The chamfer around the raised pentagon 103 makes it easier for the locator plate to fit onto the dental model, reducing the chance of flash or excess material from the 3D printing process affecting a proper fit. In one embodiment, the locator plate has chamfers on the back and sides of the pentagon, which also aid in alignment.

[0049] The locator cone 106 is another locator feature that is spaced from the raised pentagon and locator pins in a triangular arrangement and aids in locating the locator plate relative to the dental model. Preferably, the locator cone 106 can be a conical depression in the locator plate, arranged as three cones spaced apart in a triangular formation, as shown in Figures 1, 5, and 7. During the thermoforming process, a portion of the polymer material can be thermoformed into the locator cone 106, resulting in three thermoformed features within the polymer material. In some embodiments, these thermoformed cones can help orient the aligner material and dental model during downstream processes, such as laser marking.

[0050] Mounting holes 104 can be used to securely mount the locator mechanism to the base plate and to various other components during the assembly line manufacturing process.

[0051] The base plate also has small holes 107 that allow air to escape that may be trapped between the thermoforming material and the locator plate during the thermoforming process and allow for a more secure fit. In some embodiments, a vacuum system can be incorporated into the thermoforming system, and the vacuum system can provide suction through the small holes 107 to help hold the polymer material securely to the locator plate.

[0052] FIG. 1 also shows a ball plunger 108 positioned within the raised pentagon 103. The portion of the ball that extends partially outside the cylindrical body of the ball plunger 108 extends from the rectangular base of the raised pentagon and away from the apex of the triangular top of the raised pentagon. The ball plunger's spring is elastic and has one or more spring elements that apply pretension during attachment and positioning of the dental model. While a ball plunger is preferred, any other flexible element with other geometries may be used to apply tension and control any gaps during the thermoforming process. In some embodiments, the pin locating mechanism 105 can be omitted, and the dental model can be held in place using only the raised polygon and ball plunger 108.

[0053] FIG. 2 provides a top view of an alternative raised pentagon locating mechanism with two spring plungers 202a and 202b that maintain a defined pretension during attachment and thermoforming. The attachment process during thermoforming is optimized by using defined contact areas 201, which provide a defined gap 203. The defined gap, combined with the pretension from the ball plungers, balances production variability by ensuring the attachment geometry is neither too tight nor too loose. In a preferred example, the raised pentagon mechanism does not rotate. Alternatively, one or more locating mechanisms can be rotated or removed to improve modularity. These mechanisms can also secure the model during the aligner trimming process and other post-thermoforming processing steps, according to some embodiments.

[0054] The defined gaps 203 shown at the top, sides, and bottom of the pentagon are not limited to the size or range of sizes of the gap. The angled triangular sections of the pentagon have a contact area 201 with little gap so that the ball plungers 202a and 202b push back against the dental model, thus eliminating the gap at this angled contact area 201. The tips of the angled sections may have a defined gap to allow contact on both sides of the locating feature. Some gap at the tips of the triangular portions is preferred to ensure flush contact at the angled portions when the ball plungers engage during installation. Small gaps on either side of the pentagon are preferred to allow some movement.

[0055] In one example, the gap 203 on either side ranges from 0.01 to 1 mm and can vary based on several parameters, including the maximum travel of the ball plunger to ensure pretension, misalignment of the printed part or tab, and the geometric accuracy of the positioning mechanism. In a preferred example, the gap on each side is approximately 0.2 mm. In a preferred embodiment, the ball plunger travel can range from 0.7 to 1 mm.

[0056] 3 shows a 3D perspective view of the geometry of the ball plunger design, with a cylindrical body 301, an internal spring (not shown), and a ball 303 that extends partially outside the cylindrical body. The ball 303 and spring provide pre-tension when the dental model is attached to the locating mechanism for a perfect fit.

[0057] FIG. 4 shows a 3D perspective view of a locator plate system, seen from above and at an angle, including a dental model 401 mated to a locator plate 403. The dental model 401 includes a pentagonal cutout formed within a tab portion on the interior arch area 405 of the 3D-printed dental model 401. A locator tab 407 (e.g., locator tab) can be positioned within the dental arch and formed during the 3D printing process. In this embodiment, the locator feature 407 includes a pentagonal cutout formed to fit around the raised pentagon and a pin notch formed to fit around the locator pin. After trying various shapes, a pentagonal shape with a rectangular base and an isosceles triangular top demonstrated optimal fit and alignment accuracy when mating the dental model with the locator plate. A ball plunger provides tension to fill gaps and improve fit when the dental model is attached and mated to the locator feature.

[0058] FIG. 4 also shows a pin notch that assists in identifying and positioning the dental model to ensure excellent alignment. In FIG. 4, the pentagonal notch is chamfered. The chamfering makes it easier for the locator plate to fit onto the dental model and reduces the possibility of flash or excess material from the 3D printing process affecting proper fit. In one embodiment, at least one edge of the raised pentagonal feature is chamfered, which also aids in alignment.

[0059] After the dental model 401 is secured to the locator plate 403, a polymer material can be thermoformed onto the dental model. Once the thermoforming process is complete, the polymer aligner material is attached to the dental model 401 and remains attached to the dental model even after the dental model is removed from the locator plate. That is, the locator plate is removed, but the dental model is still connected to the thermoformed sheet. Furthermore, the thermoformed polymer material must be cut from the sheet and the dental model removed before finishing operations (e.g., trimming, deburring, polishing, etc.) can be performed and before the final appliance (i.e., aligner) is ready for use for a particular patient (i.e., the patient corresponding to the attached model).

[0060] The polymer material is a thin thermoforming material. The thickness of the polymer material is not particularly limited, but it must be thick enough to be thermoformed around the dental model. Preferably, the thickness of the polymer material is less than 5 mm. More preferably, the thickness of the polymer material can be about 0.05 to about 5 mm.

[0061] Examples of thermoforming materials include, but are not limited to, polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), thermoplastic polyurethane (TPU), polyvinyl chloride (PVC), and other biocompatible polymers with suitable elasticity and plasticity for thermoforming.

[0062] The polymeric material may include multilayer polymeric materials such as those described in, for example, U.S. Patent No. 10,549,511, U.S. Patent No. 10,870,263, U.S. Patent No. 10,987,907, U.S. Patent No. 11,325,358, U.S. Patent No. 10,946,630, U.S. Patent Publication No. 2022 / 0118747, PCT Application No. PCT / US2020 / 065928, PCT Application No. PCT / US2022 / 025306, and Provisional U.S. Patent Application No. 63 / 354,998, all of which are incorporated by reference in their entirety.

[0063] When the thermoforming material is exposed to heat, the material becomes more flexible, which allows the material to take on the shape of the imprint when molded and the appropriate pressure is applied.

[0064] FIG. 4 also illustrates alphanumeric characters that may be presented at various locations on the locator tab portion of the 3D printed dental model 401. The characters are preferably in the form of raised letters and are spaced from the pentagonal cutout. In FIG. 4, the alphanumeric characters are presented at three different locations on the locator tab around the pentagonal cutout. The alphanumeric characters are used to identify and match a particular 3D model. For example, a computer with a detector (e.g., using an optical character recognition camera) can scan the locator tab, read the characters, and match the dental model based on the character instructions, further streamlining the thermoforming process.

[0065] In one example, the alphanumeric characters represent a case number and / or step / architecture identifier, which may be in the form of an encryption code. In some embodiments, rather than raising the letters, the letters may be cut through the entire model, allowing for more accurate readings from an optical character recognition camera. In a preferred embodiment, the length of the raised text is at least 1 mm, which overcomes potential issues in 3D printing. In an alternative embodiment, the letters are cut completely through the thickness of the locator tab. Cutting out the letters can further reduce the amount of material required during the 3D printing process.

[0066] Figure 5 shows the locator plate of Figure 4 viewed diagonally from below. The gaps and small holes 107 allow air to escape that may be trapped between the thermoforming material and the locator plate during the thermoforming process and also allow for a more secure fit.

[0067] The distance between the arch and the locator tab can vary because each arch has a unique anatomical shape. Thermoforming digital software, combined with the lettering, is used to determine the distance for each arch. Based on the arch's known location, the software ensures that the lettering is as indicated when merging one or more locating features with the arch.

[0068] Figures 6A and 6B show models of positioning mechanisms with a chamfered, raised pentagon and both a single (Figure 6B) and dual (Figure 6A) ball spring positioned on the bottom rectangular portion of the pentagon. In one example, a single ball plunger design is used. In an alternative example, a dual ball plunger design is used. This technology is not limited to the number, size, or location of the ball plungers. An advantage of dual springs is that less spring tension may be required for each ball plunger. An advantage of a single ball plunger is that having one stronger spring plunger improves alignment of the model on the positioning mechanism and reduces the number of components that can fail. The two cavities shown in these designs are screw holes used to attach the mechanism to a larger base plate, as seen in Figures 9A-9B.

[0069] Figures 7A and 7B show an alternative circular base plate with a locating feature that sits flush with the surface of the plate. Figure 7A shows a top-down, angled 3D perspective view, and Figure 7B shows a schematic side perspective view including a dual ball plunger design.

[0070] 8 shows a diagram of a dental model 801 mating with a raised polygon 802 containing two ball plungers, according to an embodiment of the present disclosure. The dental model has locator pin cutouts, but there are no locator pins on the corresponding locator plate, and one is not required.

[0071] Although FIG. 8 shows only a few sides of the raised pentagon that are chamfered, many or few edges of the raised pentagon can be chamfered to aid in positioning the dental model on the locator plate. In some embodiments, the locator pins may also have chamfered top surfaces. The polygon 802 is preferably compact enough to fit inside all human dental arches and is chamfered to better fit and avoid fit-to-dental model issues arising from 3D printing imperfections. The polygon cutout in the dental model 801 is preferably robust enough to avoid damage or breakage during processing. Additional advantages of the polygon include its ease of manufacture, fast product orientation, easy fit-to-fit, and sufficient surface area to prevent part rotation.

[0072] 9A-9B show the locator mechanism attached to one or more base plates. FIG. 9A shows the attached structure, while FIG. 9B is an exploded view of the structure shown in FIG. 9A. A number of small holes in the base plates are connected to vacuum suction and are used during the thermoforming and milling / cutting process to further secure the thermoformed material. The vacuum / suction holes are unlimited in diameter and can vary based on the desired thermoforming system utilized. In some examples, the diameter can range from 0.1 mm to 1 mm. In a preferred example, the diameter can be approximately 0.7 mm.

[0073] In an alternative embodiment, the ball and plunger system can be modular such that the active element is removable or retractable, as shown by the retractable active element 1110 separated from the mold 1105 in FIG. 11. In addition to being modular, the insert provides additional benefits, such as improved friction in the thermoformed material due to the insert's elasticity for better ball / plunger alignment, which is beneficial to the vacuum seal of the thermoforming process. As a result, the thermoformed seal with the dental model 1401 (i.e., the polymer / thermoplastic aligner 1402) is improved, as shown in FIG.

[0074] As shown in Figures 12A-12C, a retractable active element insert can have a bottom ball plunger and a raised polygon and ball / plunger system on the opposite side of the insert. As shown in Figure 11, a raised depression or other raised shape extending from the plate can be used to apply an opposing force to the bottom ball portion of the insert.

[0075] The downward arrow in Figure 13A indicates the direction of force applied to reach the insert's zero (final) position, as seen in Figure 13B. The plate may include a clamp (as seen in Figure 13A) on the opposite side of the insert to stabilize and attach the plate but not affect the ability to remove the insert itself. Figure 13A also shows a sealing member located within a groove in the locator plate. This sealing member can help apply a vacuum to more securely hold the thermoformed aligner in place during the trimming process. An additional inner seal can be used to close the vacuum hole in the locator plate. During the trimming process, the slightly raised position shown in Figure 13A can be used to ensure that friction between the aligner material and the sealing does not interfere with model alignment. In addition to providing process stability during thermoforming, the retractable module design described herein can also provide process stability during trimming of the aligner material.

[0076] In a preferred example, the polygon is a pentagon, which is useful in that it best meets the above criteria. In a more preferred example, the pentagon has a substantially rectangular, slightly rounded base and an isosceles triangular top, with the raised pentagon located in the center of the locator plate. The points at one end are easy to align, allowing for ergonomic and self-aligning back and forth loading, and the flat surface of the rectangular portion helps the pentagon prevent the part from rotating. In some embodiments, the points of the raised polygon 802 can be trimmed or cut out to further aid in mating the dental model with the locator plate, as shown in FIG. 8.

[0077] The number of locator features is not limited. In an alternative example, the locator plate has multiple polygonal cutouts. In another example, additional locator cutouts, such as additional locator pins, may be used and optimized based on the particular design of the thermoforming system being used.

[0078] In one example, digital software is used to determine the distance to each arch. The software can help keep track of where the arches are and ensure all text is displayed when merging the locating feature with the arches.

[0079] The letters may include the case number and step / arch identifier on the edge of the polygon cutout. In one example, the letters are encrypted hexadecimal codes. The letters may be at the base of the polygon (e.g., pentagon) and cut throughout the model, allowing for more accurate readings from an optical character recognition camera.

[0080] Any suitable length of raised text from the locator tab may be used. In a preferred example, the raised text may be at least 1 mm. In a preferred example, the cut-out text is cut completely through the thickness of the locator plate.

[0081] The raised polygons, locator pins, locator plates, and any other positioning features may be chamfered. Chamfering advantageously allows for easier mating. Chamfering also advantageously helps reduce the possibility of any flashing or excess material from the 3D printing process preventing the parts from mating properly during the thermoforming process. In a preferred example, the locator plate has chamfers on the back and sides of the pentagon to aid in alignment.

[0082] The locator plate may include one or more grooves and / or holes that allow air to escape during the thermoforming process that may be trapped between the film and the plate, and these holes may be used in conjunction with a vacuum system to help hold the polymeric material securely to the locator plate.

[0083] In a preferred example, the locator pins are spaced from the raised polygon. Spacing the pins from the polygon advantageously improves the locating mechanism(s) for keeping the arch oriented in the correct position. Spacing the locator mechanism(s) from one another advantageously minimizes potential variations in the 3D arch dimensions that affect the thermoforming process. 3D printed parts often have some dimensional variation from part to part based on the accuracy of the printer. Additionally, the degree to which the 3D arch model is properly located impacts the accuracy of laser marking and robotic trimming.

[0084] The present technology further relates to methods for thermoforming aligners.

[0085] Generally, the methods of the present technology feature the use of locator plates and dental models to form specific, customized patient-specific aligners. The methods of the present technology may include the use of locator plates. As a result of incorporating the locator plates, the benefits of thermoforming are achieved, including superior fit and accuracy relative to the dental models.

[0086] In one embodiment, the method of the present technology includes several steps, as demonstrated in the flowchart of FIG. 10A.

[0087] The method begins with preparing a dental model for thermoforming (1003). The dental model may be created by printing a 3D model. This model may include a positive model of the dental arch and 3D printed locator tabs. The location of the locator tabs is not limited, but the locator tabs match each locator cutout with one or more ball plungers. In one embodiment, the locator tabs are preferably positioned inside the dental arch. Printing may include printing edges of polygonal cutouts with the 3D printed tabs and printing boundaries of pin cutouts within the 3D printed locator tabs. These features are printed to match and align with the locator plate with each cutout of the features.

[0088] Next, a locator plate having locator features described herein is provided for securing the dental model to the locator plate (1005). Preferred locator features of the locator plate include raised polygons and locator pins extending from the surface of the locator plate, which aid in positioning and securing the 3D model. The locator plate may also include a locator cone, which is a concave conical depression in the locator plate that further aids in precisely aligning the locator plate.

[0089] The 3D dental model is then secured to the locator plate by positioning locator features within each of the cutouts (1007). In a preferred example, the securing step includes positioning raised polygons within the polygon cutouts and positioning locator pins within the pin cutouts. The locator features of the locator plate ensure a consistent and secure fit with the dental model during the thermoforming process. Additionally, the 3D model can be moved to the proper position for thermoforming by repositioning the locator plate.

[0090] The raised polygon includes at least one ball plunger having a ball extending partially away from a surface of the raised polygon, which serves to secure the 3D dental model to the locator plate when the raised polygon is positioned within the polygon cutout so that the at least one ball plunger engages with the polygon cutout. When the one or more ball plungers engage, based on the desired pretension, they are neither too tight nor too loose, reducing or eliminating gaps to improve fit and finish during the thermoforming process.

[0091] Once the dental model is secured to the locator plate and in the proper position, a thermoforming material may be thermoformed onto the dental model 1011. The thermoforming material is preferably a polymer / thermoplastic sheet or film that is biocompatible and moldable onto the dental model when sufficient heat and / or pressure is applied.

[0092] In some embodiments, after thermoforming is complete, the locator plate provides additional stability during the trimming process, in which excess aligner material is trimmed or cut from the aligner.

[0093] The above method may have the following additional exemplary features.

[0094] In this example method, the raised polygon has a particular shape that helps ensure a secure fit. For example, the raised polygon of the locator plate may have an apex directed toward the incisal edge of the dental arch, which indicates the proper orientation of the 3D dental model relative to the raised polygon of the locator plate.

[0095] In this example method, the raised polygon of the locator plate and the polygonal cutout in the 3D printed locator tab are pentagonal, which is generally optimal for securing dental arches.

[0096] Additional features of the locator plate in this method include a raised polygon and three recessed locator cones formed in the surface of the locator plate from which the locator pins extend.

[0097] In some examples of the method, the recessed locator cones are positioned in a triangular arrangement relative to the raised polygon. The triangular arrangement of the locator cones ensures proper orientation of the locator plate.

[0098] The locator cone may include a thermoformed portion that aids in securing the dental model. Thus, in some examples of the present methods, thermoforming the polymer sheet further includes thermoforming a portion of the polymer sheet within the concave locator cone. Furthermore, the triangular arrangement of the concave locator cone, when transferred to the thermoformed polymer sheet, may indicate an orientation of the thermoformed polymer sheet. For example, the orientation of the triangular arrangement of the concave locator cone may have a specific location relative to the incision in the dental arch model. In such embodiments, knowing the position of the locator cone may indicate the position of the dental arch model.

[0099] FIG. 10B illustrates another exemplary embodiment of the method. FIG. 10B includes the same steps as those shown in the method of FIG. 10A, but also includes additional features. For example, in step 1009, the model secured to the locator plate is transported to a different station within the processing system. For example, a conveyor belt or a PUK system can be used to transport the model to a quality control station, such as an optical quality control station. Again, a locator plate with a locator mechanism is used in the transport and can be used to position the locator plate within the quality control system for optical analysis. Once quality is confirmed, the locator plate can be transported (e.g., using a conveyor belt, robotic control, a PUK system, etc.) to a downstream processing station, such as a thermoforming station. If the quality control system determines there is a problem with the model, the locator plate can be ejected from the system or returned to an upstream processing location.

[0100] After thermoforming the polymer sheet onto the dental model secured to the locator plate (step 1011), the system can retransport the locator plate to a different location (e.g., another quality control station, a trimming station, etc.). In the method shown in FIG. 10B, the locator plate containing the model with the thermoformed sheet is transported to a trimming station for trimming or milling of the thermoformed sheet. Again, a locator plate with a locator mechanism can be used to position the locator plate within the trimming station.

[0101] The present technology is further directed to a system for thermoforming an orthodontic aligner having a locator plate with a raised polygon and one or more ball plungers, and optionally locator pins extending from a surface of the locator plate. The thermoforming system includes the above-described three-dimensional dental model and locator plate to manufacture an aligner made from a thermoformable material.

[0102] In addition to the method, the present technology includes embodiments of a thermoforming system that utilizes a locator plate.

[0103] Specifically, the system includes a 3D dental model, the 3D dental model including a positive model of a dental arch and a 3D printed locator tab positioned within the dental arch. The dental model is based on a digital scan of the patient's teeth or a physical impression of the patient's teeth. Preferably, the dental model is based on a digital scan of the patient's teeth using a mobile operating system device.

[0104] The example system also includes a heat source for thermoforming a polymer sheet onto the 3D dental model once secured to the locator plate. The heat source must heat the thermoforming material sufficiently so that the material will form onto the dental model. The temperature to which the heat is applied depends on the desired thermoforming material.

[0105] In some examples of the system, the system includes printing a 3D dental model that defines edges of polygonal cutouts in the 3D printed locator tabs and boundaries of pin notches in the 3D printed locator tabs.

[0106] In an additional example of the system, the 3D dental model can be mated with a locator plate by placing a raised polygon into the polygon cutout and a locator pin into the pin cutout. A locator mechanism including, for example, a raised polygon, one or two ball spring plungers, a locator pin cutout, and a locator cone optimizes the thermoforming process by precisely orienting the locator plate relative to the dental model for a secure fit when the thermoforming material is heated and pressed onto the dental model.

[0107] In some example systems, the 3D printed locator tabs include cut-out or raised letters positioned along one or more edges of the polygonal cutout. In a preferred example, the letters are in the form of a hexadecimal code and may be cut through the entire locator plate. The letters aid in identification and command to the thermoforming system using any suitable detector, such as a camera with optical character recognition software.

[0108] For identification purposes, the system further includes a camera for viewing and identifying notched or raised characters positioned along one or more edges of the polygonal notch.

[0109] With respect to the locator plate of the system, in some examples, the locator plate further defines a raised polygon and three recessed locator cones as locator features formed within the surface of the locator plate from which the locator pins extend, the recessed locator cones being positioned in a triangular arrangement relative to the raised polygon. When transferred to the thermoformed polymer sheet, the triangular arrangement of the recessed locator cones is useful for indicating the orientation of the thermoformed polymer sheet.

[0110] Specific embodiments and methods for securing a thermoformed model are disclosed. However, it will be apparent to those skilled in the art that many more modifications beyond those already described are possible without departing from the inventive concepts herein. Accordingly, the subject matter of the invention should not be limited except within the spirit of the present disclosure. Moreover, in interpreting this disclosure, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms "comprises" and "comprising" should be interpreted to refer to elements, components, or steps in a non-exclusive manner, indicating that the referenced element, component, or step may be present, utilized, or combined with other elements, components, or steps not expressly referenced.

Claims

1. 1. A locator plate for receiving and fixing an individually unique dental model, said locator plate comprising: a raised pentagon extending from a surface of the locator plate and having a rectangular base and a triangular top; at least one ball plunger positioned within the raised pentagon, the at least one ball plunger having a cylindrical body, a spring, and a ball extending partially outside the cylindrical body; the locator plate, wherein a portion of the ball that extends partially outside the cylindrical body of the ball plunger extends from the rectangular base of the raised pentagon and is spaced from an apex of the triangular top of the raised pentagon.

2. The locator plate of claim 1 , wherein said raised pentagon is chamfered.

3. The locator plate of any one of claims 1 to 2, wherein the ball is located partially within the cylinder and engages the spring for movement along the longitudinal axis of the cylinder.

4. The locator plate of any one of claims 1 to 3, wherein the locator plate comprises raised letters spaced from the raised pentagons.

5. 5. The locator plate of claim 1, further comprising a dental model attached to the raised pentagon for forming a dental aligner, wherein the ball plunger engages with a portion of the dental model to secure the dental model to the locator plate.

6. The locator plate of claim 5 further comprising a polymer sheet stretched over the dental model.

7. The locator plate of any preceding claim, wherein the at least one ball plunger comprises a pair of ball plungers positioned within the raised pentagon.

8. 1. A method of securing dental aligners, comprising: printing a 3D dental model including a positive model of a dental arch and a 3D printed locator tab positioned within the dental arch, wherein printing the 3D dental model includes printing edges of a polygonal notch in the 3D printed locator tab; providing a locator plate having a raised polygon extending from a surface of the locator plate, the raised polygon including at least one ball plunger having a ball extending partially away from a surface of the raised polygon; fixing the 3D dental model to the locator plate by positioning the raised polygon within the polygonal cutout such that the at least one ball plunger engages with the polygonal cutout; thermoforming a polymer sheet onto the 3D dental model secured to the locator plate; The method comprising:

9. 9. The method of claim 8, wherein the raised polygon of the locator plate has an apex directed toward the incisal edge of the dental arch, the apex indicating the proper orientation of the 3D dental model relative to the raised polygon of the locator plate.

10. The method of any one of claims 8 to 9, wherein the raised polygon of the locator plate and the polygonal cutout in the 3D printed locator tab are pentagonal.

11. 11. The method of claim 10, wherein the pentagonal raised polygon includes a rectangular portion and a triangular portion, and a vertex of the triangular portion is removed such that a gap occurs between the vertex of the triangular portion and the 3D dental model.

12. 12. The method of claim 11, wherein when the 3D dental model is secured to the locator plate, a defined gap exists between three sides of the rectangular portion of the pentagonal raised polygon and the polygonal cutout in the 3D printed locator tab.

13. The method of claim 12 , wherein the at least one ball plunger comprises a pair of ball plungers positioned within the raised pentagon.

14. The method of any one of claims 8 to 13, further comprising trimming the thermoformed polymer sheet after thermoforming.

15. The method of any one of claims 8 to 14, further comprising transporting the 3D dental model fixed to the locator plate to a quality control station.

16. 16. The method of any one of claims 8 to 15, further comprising transporting the 3D dental model fixed to the locator plate to a different location using the 3D printed locator tab for further processing and positioning the locator plate in the different location.

17. 1. A system for thermoforming orthodontic aligners, comprising: a locator plate having a raised polygon extending from a surface of the locator plate; at least one ball plunger positioned within the raised pentagon, the at least one ball plunger having a cylindrical body, a spring, and a ball extending partially outside the cylindrical body; 1. A 3D dental model comprising a positive model of a dental arch and 3D printed locator tabs positioned within the dental arch, the 3D dental model defines edges of a polygonal cutout in the 3D printed locator tab; the 3D dental model mates with the locator plate by positioning the raised polygon within the polygonal cutout and engaging the ball of the ball plunger with a portion of the polygonal cutout; a heat source for thermoforming a polymer sheet onto the 3D dental model when secured to the locator plate; The system comprising:

18. 20. The system of claim 17, wherein the 3D printed locator tab includes cutout or raised letters positioned along one or more edges of the polygonal cutout.

19. 20. The system of claim 18, further comprising a camera for viewing and identifying the cutout or raised characters positioned along one or more edges of the polygonal cutout.

20. The system of any one of claims 17 to 19, wherein the locator plate further defines a plurality of channels in fluid communication with a vacuum pump for generating a vacuum within the locator plate.

21. 21. The system of any one of claims 17 to 20, wherein the locator plate has a modular design that allows the raised polygon to be secured to the locator plate and the raised polygon to be removed from the locator plate.

22. 22. The system of claim 17, wherein the locator plate further comprises a removable active insert including the at least one ball plunger positioned within the raised polygon, and a bottom ball plunger extending from a surface of the removable active insert opposite the raised polygon.

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