System and method for modifying surface of additive manufacturing object

Abstract

Systems and methods for processing objects of additive manufacturing are described herein. For example, in some embodiments, the system comprises: a controller configured to provide one or more control signals; a heater coupled to the controller wherein the heater comprises one or more heating elements arranged to heat a blasting medium in response to the one or more control signals; a chamber coupled to the controller, where the chamber includes an agitatable drum shaped to receive a plurality of additive manufacturing objects and agitate the plurality of additive manufacturing objects in response to the one or more control signals; and a filler coupled to the controller, where the filler includes a nozzle operable to direct a plurality of thermally conductive particles in a blasting medium toward a plurality of additive manufacturing objects within the agitatable drum in response to the one or more control signals.

Description

Cross - Reference to Related Applications

[0001] This application claims the benefit of priority of U.S. Provisional Patent Application No. 63 / 375,738, filed on September 15, 2022, which is hereby incorporated by reference in its entirety. Technical Field

[0002] This technology generally relates to manufacturing processes and, in particular, to methods for modifying the surface of an additive - manufactured object. Background Art

[0003] Additive manufacturing includes various techniques for building 3D objects from multiple layers of material. The surface characteristics of objects manufactured using conventional additive - manufacturing techniques may be unsatisfactory for certain applications. For example, additively - manufactured objects may exhibit excessive surface roughness and porosity, which can lead to staining, odor problems, liquid penetration, and microbial contamination when exposed to a physiological environment (e.g., inside a patient's mouth). Conventional chemically - based surface - finishing processes may be impractical for the large - scale production of additively - manufactured objects due to the use of expensive, single - use reagents. Chemical treatments may also compromise the mechanical properties of the object and / or may leave residual materials within the object that pose a safety risk to the patient's use. Brief Description of the Drawings

[0004] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale. Instead, emphasis is placed on clearly illustrating the principles of the present disclosure.

[0005] Figure 1 is a flowchart of a method for manufacturing and post - processing an additively - manufactured object according to an embodiment of the present technology.

[0006] Figure 2 is a partial schematic view of a system for additive manufacturing according to an embodiment of the present technology.

[0007] Figure 3 is a schematic view of a system for manufacturing and processing an additively - manufactured object according to an embodiment of the present technology.

[0008] Figure 4 is a flowchart showing a method for processing an additively - manufactured object according to an embodiment of the present technology.

[0009] Figure 5A is a partial schematic view of a system for processing one or more additively - manufactured objects according to an embodiment of the present technology.

[0010] Figure 5BPartial schematic view of a receptacle for processing one or more additive manufacturing objects according to an embodiment of the present technology.

[0011] Figure 6 Flowchart showing another method for processing additive manufacturing objects according to an embodiment of the present technology.

[0012] Figure 7A Partial schematic view of a system for processing additive manufacturing objects according to an embodiment of the present technology.

[0013] Figure 7B Partial schematic view of another system for processing additive manufacturing objects according to an embodiment of the present technology.

[0014] Figure 8A Perspective view of a palatal expander configured according to an embodiment of the present technology.

[0015] Figure 8B Shows surface modification of a palatal expander using a heating element according to an embodiment of the present technology.

[0016] Figure 8C Shows surface modification of a palatal expander using a movable heating element according to an embodiment of the present technology.

[0017] Figure 9A Shows a representative example of a tooth repositioning appliance configured according to an embodiment of the present technology.

[0018] Figure 9B Shows a tooth repositioning system including multiple appliances according to an embodiment of the present technology.

[0019] Figure 9C Shows a method of orthodontic treatment using multiple appliances according to an embodiment of the present technology.

[0020] Figure 10 Shows a method for designing an orthodontic appliance according to an embodiment of the present technology.

[0021] Figure 11 Shows a method for digitally planning orthodontic treatment and / or the design or manufacture of an appliance according to an embodiment of the present technology. Detailed Description

[0022] The present technology relates to a method for processing an object manufactured by additive manufacturing. For example, in some embodiments, the method involves receiving an object manufactured using an additive manufacturing process. The method may include modifying the surface of the object by applying a blasting medium (e.g., a plurality of thermally conductive particles) to the surface of the object. The blasting medium may be heated to an elevated temperature to facilitate mechanical deformation of the object surface. For example, the mechanical deformation may reduce the roughness and / or porosity of the object surface. Optionally, the method may include collecting the blasting medium for reuse.

[0023] As another example, a method may involve obtaining topography data (e.g., height data) of the surface of an object manufactured using an additive manufacturing process. The method may further include modifying the object surface based on the topography data by applying heat to the surface of the object. For example, the applied heat may at least partially melt the surface of the object to reduce roughness and / or porosity. In some embodiments, the heat is applied by at least one flame generator, and the positioning (e.g., vertical position) and / or flame characteristics (e.g., flame size and / or intensity) of the flame generator may be customized according to the specific surface topography of the object.

[0024] The present technology may provide many advantages over conventional surface finishing processes, such as low cost, scalability for mass production, utilization of reusable materials, avoidance of using toxic reagents, and / or maintaining the mechanical integrity of the final product. In some embodiments, the techniques described herein are used to improve the surface characteristics of additively manufactured dental appliances (e.g., palatal expanders), which may be beneficial for enhancing the appearance of the appliance, reducing staining and odor, and / or reducing the infiltration of fluids, microorganisms, and / or other contaminants.

[0025] Embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which like reference numerals refer to like elements throughout the several views, and in which example embodiments are shown. However, the embodiments of the claims may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The examples set forth herein are non-limiting examples and are merely examples among other possible examples.

[0026] As used herein, the terms “vertical,” “horizontal,” “lateral,” “upper,” and “lower” may refer to the relative directions or positions of the features of the embodiments disclosed herein in view of the orientation shown in the figures. For example, “upper” or “uppermost” may refer to a feature that is positioned closer to the top of the page than another feature. However, these terms should be construed broadly to include embodiments having other orientations, such as inverted or tilted orientations, where top / bottom, above / below, over / under, up / down, and left / right may be interchanged depending on the orientation.

[0027] The titles provided herein are for convenience only and do not interpret the scope or meaning of the claimed technology. Embodiments under any one title may be used in combination with embodiments under any other title. I. Overview of Additive Manufacturing Technology

[0028] Figure 1 is a flow chart providing an overall overview of a method 100 for manufacturing and post-processing an additively manufactured object according to an embodiment of the present technology. The method 100 can be used to produce many different types of additively manufactured objects, such as orthodontic appliances (e.g., aligners, palatal expanders, retainers, attachments, attachment placement devices), restorative objects (e.g., crowns, veneers, implants), and / or other dental devices (e.g., oral sleep apnea appliances, mouth guards).

[0029] The method 100 begins at block 102 by producing an object using an additive manufacturing process. The additive manufacturing process can implement any suitable technique known to those skilled in the art. Additive manufacturing (also referred to herein as "3D printing") includes various techniques for making 3D objects directly from digital models through an additive process. In some embodiments, additive manufacturing includes depositing a precursor material onto a build platform. The precursor material can be cured, polymerized, melted, sintered, fused, and / or otherwise solidified to form a part of the object and / or combine the part with a previously formed part of the object. In some embodiments, the additive manufacturing techniques provided herein build the object geometry in a layer-by-layer manner, where successive layers are formed in discrete build steps. Alternatively or in combination, the additive manufacturing techniques described herein can allow for continuous building of the object geometry.

[0030] Examples of additive manufacturing techniques suitable for use with the methods described herein include, but are not limited to, the following: (1) vat photopolymerization, in which an object is constructed from a vat of liquid photopolymer resin, including techniques such as stereolithography (SLA), digital light processing (DLP), continuous liquid interface production (CLIP), two-photon induced photopolymerization (TPIP), and volumetric additive manufacturing; (2) material jetting, in which materials are jetted onto a build platform using a continuous or drop-on-demand (DOD) method; (3) binder jetting, in which alternating layers of build material (e.g., powder-based material) and binder material (e.g., liquid binder) are deposited by a print head; (4) material extrusion, in which materials are extruded through a nozzle, heated, and deposited layer by layer, and direct ink writing (DIW), such as fused deposition modeling (FDM); (5) powder bed fusion, including techniques such as direct metal laser sintering (DMLS), electron beam melting (EBM), selective heat sintering (SHS), selective laser melting (SLM), and selective laser sintering (SLS); (6) sheet lamination, including techniques such as laminated object manufacturing (LOM) and ultrasonic additive manufacturing (UAM); and (7) directed energy deposition, including techniques such as laser engineered net shaping, directed light fabrication, direct metal deposition, and 3D laser cladding. Optionally, the additive manufacturing process may use a combination of two or more additive manufacturing techniques.

[0031] For example, a vat photopolymerization process may be used to fabricate an additive manufacturing object, in which light is used to selectively cure a curable material (e.g., polymer resin) in a vat or reservoir. Each layer of curable material may be selectively exposed to light in a single exposure (e.g., DLP) or by scanning a light beam over the layer (e.g., SLA). Depending on the relative positions of the vat, light source, and build platform, vat curing may be performed in a "top-down" or "bottom-up" method.

[0032] As another example, high-temperature lithography (also referred to as "thermal lithography") can be used to fabricate additive manufacturing objects. High-temperature lithography can include any photopolymerization process that involves heating a photopolymerizable material (e.g., a polymer resin). For example, high-temperature lithography can involve heating the material to a temperature of at least 30 °C, 40 °C, 50 °C, 60 °C, 70 °C, 80 °C, 90 °C, 100 °C, 110 °C, or 120 °C. In some embodiments, the material is heated to a temperature in the range of 50 °C to 120 °C, 90 °C to 120 °C, 100 °C to 120 °C, 105 °C to 115 °C, or 105 °C to 110 °C. Heating can reduce the viscosity of the photopolymerizable material and / or increase the reactivity of the photopolymerizable material before and / or during curing. Thus, high-temperature lithography can be used to fabricate objects from materials that are highly viscous and / or have poor flowability, which can exhibit improved mechanical properties (e.g., stiffness, strength, stability) upon curing compared to other types of materials. For example, high-temperature lithography can be used to fabricate objects from materials that have a viscosity of at least 5 Pa-s, 10 Pa-s, 15 Pa-s, 20 Pa-s, 30 Pa-s, 40 Pa-s, or 50 Pa-s at 20 °C. Representative examples of high-temperature lithography processes that can be incorporated into the methods herein are described in International Publication Nos. WO2015 / 075094, WO2016 / 078838, WO2018 / 032022, WO2020 / 070639, WO2021 / 130657, and WO2021 / 130661, the disclosures of each of which are incorporated herein by reference in their entirety.

[0033] In some embodiments, additive manufacturing objects are fabricated using continuous liquid interphase production (also referred to as "continuous liquid interphase printing"), wherein the object is continuously built from a reservoir of photopolymerizable resin by forming a gradient of a partially cured resin between the build surface of the object and a polymerization-inhibiting "dead zone". In some embodiments, a semipermeable membrane is used to control the delivery of a photopolymerization inhibitor (e.g., oxygen) into the dead zone in order to form a polymerization gradient. Representative examples of continuous liquid interphase production processes that can be incorporated into the methods herein are described in U.S. Patent Publication Nos. 2015 / 0097315, 2015 / 0097316, and 2015 / 0102532, the disclosures of each of which are incorporated herein by reference in their entirety.

[0034] As another example, the continuous additive manufacturing method can achieve the continuous construction of an object geometry by causing continuous movement of the build platform during the irradiation phase (e.g., along the vertical or Z direction) such that the depth of hardening of the irradiated photopolymer is controlled by the speed of movement, thereby enabling continuous polymerization of the material on the build surface. Such methods are described in U.S. Patent No. 7,892,474, the disclosure of which is incorporated herein by reference in its entirety. In another example, the continuous additive manufacturing method can involve extruding a composite material consisting of a curable liquid material surrounding a solid strand. The composite material can be extruded along a continuous three-dimensional path to form an object. Such methods are described in U.S. Patent No. 10,162,264 and U.S. Patent Publication No. 2014 / 0061974, the disclosures of which are incorporated herein by reference in their entireties. In yet another example, the continuous additive manufacturing method can utilize a "heliolithography" method, in which a focused radiation is used to cure a liquid photopolymer while continuously rotating and raising the build platform. Thus, the object geometry can be continuously constructed along a helical construction path. Such methods are described in U.S. Patent Publication No. 2014 / 0265034, the disclosure of which is incorporated herein by reference in its entirety.

[0035] In another example, a volumetric additive manufacturing (VAM) process can be used to fabricate an additive manufactured object, in which the entire object is produced from a 3D volume of resin in a single printing step, without the need for layer-by-layer construction. During the VAM process, the entire build volume is irradiated with energy, but the projected pattern is configured such that only certain voxels will accumulate a sufficient energy dose to be cured. Representative examples of VAM processes that can be incorporated into the present technology include tomographic volume printing, holographic volume printing, multiphoton volume printing, and xolography. For example, a tomographic VAM process can be performed by projecting a 2D optical pattern into a rotating volume of photosensitive material at a perpendicular and / or angled incidence to produce a cured 3D structure. A holographic VAM process can be performed by projecting a holographic light pattern into a stationary reservoir of photosensitive material. The xolography process can use a photo-switchable photoinitiator to induce local polymerization within a volume of photosensitive material when linearly excited by crossing beams of different wavelengths. Additional details of VAM processes suitable for use with the present technology are described in U.S. Patent No. 11,370,173, U.S. Patent Publication No. 2021 / 0146619, U.S. Patent Publication No. 2022 / 0227051, International Publication No. WO2017 / 115076, International Publication No. WO2020 / 245456, International Publication No. WO2022 / 011456, and U.S. Provisional Patent Application No. 63 / 181,645, the disclosures of each of which are incorporated herein by reference in their entirety.

[0036] In yet another example, an additive manufactured object can be fabricated using a powder bed fusion process (e.g., SLS), which involves selectively fusing layers of powder material using a laser beam according to a desired cross-sectional shape in order to build the object geometry. As another example, an additive manufactured object can be fabricated using a material extrusion process (e.g., fused deposition modeling), which involves selectively depositing a filament material (e.g., a thermoplastic polymer) in a layer-by-layer manner in order to form the object. In yet another example, an additive manufactured object can be fabricated using a material jetting process, which involves jetting or extruding one or more materials onto a build surface to form successive layers of the object geometry.

[0037] An object of additive manufacturing can be made of any suitable material or combination of materials. In some embodiments, the object of additive manufacturing is formed of a single type of material such that the entire object has the same chemical composition. Alternatively, the object of additive manufacturing can be made of multiple different material types (e.g., at least two, three, four, five, or more different material types) such that different parts of the object can have different chemical compositions. The material types can differ from each other in terms of composition, curing conditions (e.g., curing energy wavelength), material properties before curing (e.g., viscosity), material properties after curing (e.g., stiffness, strength, transparency), and the like. In some embodiments, the object of additive manufacturing is formed of multiple materials in a single manufacturing step. For example, a multi-tip extrusion device can be used to selectively dispense multiple types of materials from different material supply sources in order to manufacture an object of multiple different materials. Examples of such methods are described in U.S. Patent No. 6,749,414 and U.S. Patent No. 11,318,667, the disclosures of which are incorporated herein by reference in their entirety. Alternatively or in combination, the object of additive manufacturing can be formed of multiple materials in multiple sequential manufacturing steps. For example, a first part of the object can be formed of a first material according to any method herein, then a second part of the object can be formed of a second material according to the methods herein, and so on until the entire object has been formed.

[0038] After the object of additive manufacturing has been made, the object can undergo one or more additional process steps, also referred to herein as "post-processing". As described in detail below with respect to blocks 104-108, post-processing can include removing excess material from the object, modifying the object surface, and / or performing additional operations.

[0039] For example, at block 104, method 100 continues with removing excess material from the object of additive manufacturing. The excess material can include unbound precursor material (e.g., unsintered powder) and / or other unwanted material (e.g., debris) remaining on or within the object after the additive manufacturing process. The excess material can be removed in many different ways, such as exposing the object to a solvent (e.g., via spraying, immersion), heating or cooling the object, applying a vacuum to the object, blowing a pressurized gas onto the object, applying a mechanical force to the object (e.g., vibration, agitation, centrifugation, tumbling, brushing), and / or other suitable techniques. Optionally, the excess material can be collected and / or processed for reuse.

[0040] At block 106, method 100 may include modifying at least one surface of an object. The surface modification may be applied to a portion or all of the surfaces of the object (e.g., external surface and / or internal surface) to alter one or more surface properties such as surface finish (e.g., roughness, waviness, lay), porosity, visual appearance (e.g., gloss, transparency, visibility of printed lines), hydrophobicity, and / or chemical reactivity. In some embodiments, the surface treatment is configured to reduce or eliminate undesirable surface properties that may be present in the object after an additive manufacturing process. For example, objects manufactured using certain types of additive manufacturing processes (e.g., SLS) may exhibit a relatively high degree of surface roughness, which may cause problems such as staining, odor, unappealing visual appearance, and / or discomfort when worn by a patient. Surface roughness can be quantified in various ways (e.g., using the arithmetic mean roughness (Ra) (corresponding to the deviation of the surface from the arithmetic mean height of the surface)) and can be measured according to techniques known to those skilled in the art (including contact methods (e.g., stylus profilometer) and non-contact methods (e.g., interferometer, microscope, focus variation, confocal chromatic aberration)). In some embodiments, the initial Ra of the object is at least 5 μm, 10 μm, 15 μm, or 20 μm; and the surface treatment is configured to reduce the Ra to no more than 10 μm, 5 μm, 4 μm, 3 μm, 2 μm, or 1 μm.

[0041] As another example, some additive manufactured objects may have a relatively high degree of porosity, which may lead to the penetration of undesirable fluids, microorganisms, and / or other contaminants. Porosity can be quantified as the percentage of void volume in the total volume of the object. In some embodiments, the initial porosity of the object is at least 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%; and the surface treatment is configured to reduce the porosity to no more than 1%, 0.75%, 0.5%, 0.25%, 0.1%, or 0.05%.

[0042] In another example, the surface modification process of block 106 may include applying one or more materials (e.g., coatings (e.g., polymer coatings)) to the object surface. The coating may be applied to one or more surfaces of the object for various purposes, including but not limited to: providing a smooth surface finish, which may be beneficial for aesthetics and / or improving user comfort if the object is intended to be in contact with the user's body (e.g., a dental appliance worn on teeth); coloring the object and / or applying other aesthetic features; improving scratch resistance and / or other mechanical properties; providing antimicrobial properties; and incorporating therapeutic agents into the object for controlled release.

[0043] The surface modification process of the frame 106 can be performed in many different ways. For example, in some embodiments, the surface of the object is mechanically deformed (e.g., plastically deformed) and / or worn by applying a suitable medium (such as a solid medium (e.g., particles), a fluid medium (e.g., a pressurized fluid such as pressurized air), or a suitable combination thereof (e.g., a particle slurry in a pressurized fluid)) to the object. As another example, the surface of the object can be softened, melted, or otherwise deformed by applying heat. In another example, the surface modification can be accomplished by a chemical process (e.g., vapor polishing, solvents, vapor deposition). Additional details of techniques suitable for surface modification of additive manufacturing objects are described in Section II below.

[0044] At block 108, method 100 can optionally include additional post-processing of the object. Examples of such processing include, but are not limited to: cleaning the object (e.g., washing), post-curing the additive manufacturing object, trimming, or otherwise separating the object from any substrates, supports, and / or other structures that are not intended to be present in the final product, and packaging the object for shipping.

[0045] For example, in embodiments where the object is still in a partially cured "green" state after the additive manufacturing process of block 102, post-curing can be used. Thus, the post-curing step can increase the degree of curing of the object to its final usable state. Post-curing can provide various benefits, such as improving the material properties of the object (e.g., stiffness, strength, glass transition temperature) and / or temperature stability. Post-curing can be performed by applying energy (e.g., ultraviolet light, visible light, infrared light, microwaves, or a suitable combination thereof) to the object. However, in other embodiments, post-curing is optional and can be omitted.

[0046] As another example, the process of block 108 can include separating the object from the substrate. In some embodiments, the substrate is the build platform that mechanically supports the object during the manufacturing and post-processing steps described herein. The additive manufacturing object can be connected to the substrate via sacrificial regions of material (e.g., supports and / or rafts). Thus, the object can be separated from the substrate, for example, by applying pressure to break the sacrificial regions. However, in other embodiments, the object can be manufactured without any sacrificial regions.

[0047] Figure 1 The illustrated method 100 can be modified in many different ways. For example, although the above steps of method 100 are described with respect to a single object, method 100 can be used to sequentially or simultaneously manufacture and post-process any suitable number of objects, such as dozens, hundreds, or thousands of additive manufacturing objects. As another example, Figure 1The sequencing of the processes shown in. Some of the processes of method 100 may be omitted, such as the process of block 108. Method 100 may also include Figure 1 additional processes not shown in.

[0048] Figure 2 is a partial schematic view of a system 200 for additive manufacturing configured according to an embodiment of the present technology. System 200 may be used to fabricate any embodiment of the additive manufacturing objects described herein. For example, system 200 may be used to produce an object according to Figure 1 block 102 of method 100.

[0049] System 200 is configured to use a powder bed fusion technique (e.g., SLS) to fabricate an additive manufactured object 202 (“object 202”). As Figure 2 shown, system 200 includes a bed of powder 204 (e.g., polymer powder) on a build platform 206. System 200 also includes an energy source 208 (e.g., a laser source or an electron beam source) that outputs energy 210 (e.g., a laser or an electron beam) at an intensity configured to sinter, melt, or otherwise fuse the powder 204 into an adherent object layer 212 on the build platform 206 and / or a previously formed portion of object 202. A scanner 214 (e.g., mirrors and / or other optical elements) may be used to direct the energy 210 over the powder 204 in a suitable pattern to form the object layer 212. The geometry of the object layer 212 may correspond to the desired geometry of the corresponding cross-section of object 202.

[0050] Once the object layer 212 is formed, the build platform 206 may be lowered by a predetermined amount. Then, a material source 216 (schematically shown) may apply a new layer of powder 204 over the formed object layer 212 and the previously deposited powder 204. For example, the material source 216 may include a reservoir of powder 204 (e.g., a hopper, a feed cylinder with a movable piston) and a leveling device (e.g., a doctor blade, a recoater, a roller) that applies and levels the deposited powder 204 into a relatively thin and uniform layer. The manufacturing process may be repeated to iteratively build individual object layers 212 on the build platform 206 until the object 202 is complete. Then, the object 202 may be removed from the system 200 for post-processing.

[0051] In some embodiments, system 200 further includes a controller 218 that is operatively coupled to build platform 206, energy source 208, and material source 216 to control their operations. Controller 218 can be or include a computing device that includes one or more processors and a memory storing instructions for performing the additive manufacturing operations described herein. For example, controller 218 can receive a digital data set (e.g., a 3D model) representative of an object 202 to be manufactured, determine a plurality of object cross-sections for building object 202 from powder 204, and can transmit instructions to energy source 208 to output energy 210 to form a plurality of object layers 212 corresponding to the object cross-sections. Additionally, controller 218 can also determine and control other operating parameters, such as the positioning (e.g., height) of build platform 206 and / or the amount of powder 204 deposited by material source 216.

[0052] Although Figure 2 a representative example of a system 200 for additive manufacturing is shown, this is not meant to be limiting, and other types of additive manufacturing systems can be used to implement the methods described herein, e.g., vat photopolymerization systems, material jetting systems, binder jetting systems, FDM systems, sheet lamination systems, or directed energy deposition systems.

[0053] Figure 3 is a schematic diagram of a system 300 for manufacturing and processing additive manufacturing objects according to an embodiment of the present technology. System 300 can be used for any embodiment of manufacturing the additive manufacturing objects described herein. For example, system 300 can be used to produce and post-process objects according to Figure 1 method 100 therein.

[0054] System 300 includes an additive manufacturing subsystem 302 that is configured to manufacture one or more additive manufacturing objects using any of the additive manufacturing techniques described herein. For example, additive manufacturing subsystem 302 can be or include a powder bed fusion system, such as Figure 2 system 200. In such an embodiment, the manufactured object can be transported to a depowdering subsystem 304 to remove excess powder prior to subsequent post-processing. Depowdering subsystem 304 can include mechanisms using any suitable combination of mechanical motion (e.g., vibration, rotation, agitation), pressurized gas (e.g., compressed air), vacuum, brushes, etc. to remove powder from the object. Optionally, the removed powder can be processed by a powder recovery subsystem 306 for reuse. In some embodiments, powder recovery subsystem 306 is configured to filter contaminants from the removed powder, mix the removed powder with fresh powder, perform powder conditioning and / or other suitable operations to prepare the powder for subsequent use by additive manufacturing subsystem 302.

[0055] An object fabricated by the additive manufacturing subsystem 302 is transported to the surface modification subsystem 308. As described in more detail below, the surface modification subsystem 308 can be configured to alter one or more surface properties of the object, such as surface roughness, porosity, visual appearance, hydrophobicity, chemical reactivity, and the like.

[0056] Subsequently, the object can be transported to the cleaning subsystem 310 to remove debris, contaminants, and / or any other unwanted materials. For example, the cleaning subsystem 310 can include means for cleaning the object via ultrasonic cleaning techniques, solvents, heated fluids, and / or a suitable combination thereof. The object can then be transported to the packaging subsystem 312 for packaging for shipping and use.

[0057] Figure 3 The illustrated system 300 can be modified in various ways. For example, although the illustrated embodiment is configured to process objects fabricated using powder bed fusion techniques, this is not intended to be limiting, and the system 300 can be applicable to objects fabricated using other types of additive manufacturing techniques. Additionally, Figure 3 any of the illustrated subsystems 302 - 312 can be combined with each other to form larger subsystems or can be subdivided into smaller subsystems.

[0058] Additionally, the system 300 can include Figure 3 other components not shown. For example, the system 300 can include means for transporting objects and / or powder between any of the subsystems 302 - 312, such as conveyor belts, robotic assemblies, etc. The system 300 can also include one or more controllers configured to monitor and control any operations performed by the subsystems 302 - 312. In some embodiments, the system 300 includes additional subsystems for post - curing the object, separating the object from the substrate, and / or other applicable post - processing operations. II. Surface Modification of the Object of Additive Manufacturing

[0059] Figure 4 is a flowchart showing a method 400 for processing additively manufactured objects according to an embodiment of the present technology. The method 400 can be performed using any suitable system or apparatus (e.g., the embodiments described below in connection with Figure 5A and Figure 5B ). In some embodiments, portions or all of the process of the method 400 are implemented as computer - readable instructions (e.g., program code) configured to be executed by one or more processors of a computing device. The method 400 can be combined with any other method described herein (e.g., Figure 1 method 100).

[0060] Method 400 begins at block 402 by receiving an object made by additive manufacturing. In some embodiments, the object is a dental appliance, such as an aligner, a palatal expander, a retainer, etc. The object can be made using any additive manufacturing technique described herein and can be made of any suitable material or combination of materials. For example, in some embodiments, the object is made partially or entirely of a thermoplastic material, such as polyamide (e.g., nylon), thermoplastic polyester, polycarbonate, thermoplastic polyurethane, polypropylene, polyethylene, acrylic resin, polyetheretherketone, polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, polyetherimide, polyethersulfone, styrene block copolymer (SBC), thermoplastic elastomer (TPE), thermoplastic vulcanizate (TPV) elastomer, block copolymer elastomer, polyolefin blend elastomer, thermoplastic copolyester elastomer, thermoplastic polyamide elastomer, or a suitable copolymer or combination thereof. In embodiments where the object is intended to be used on or within a patient's body (e.g., intraorally), the material can be a biocompatible material.

[0061] At block 404, method 400 continues by applying a heating medium to the object to modify the object surface. The medium can be any material that can be used to modify the surface of the object via mechanical forces, such as mechanical deformation (e.g., plastic deformation) and / or abrasion. For example, the medium can be a solid medium (e.g., a plurality of particles), a fluid medium (e.g., a pressurized fluid), or a combination thereof (e.g., a slurry of particles in a fluid). The medium can be an abrasive medium that produces mechanical deformation and abrasion of the object surface or a non-abrasive medium that produces mechanical deformation of the object surface but no abrasion of the object surface.

[0062] For example, in some embodiments, the medium is or includes a sandblasting medium that includes a plurality of particles (e.g., beads, steel grit, sand, powder) that are configured to be pressurized and propelled towards the object surface to cause mechanical deformation and / or abrasion. In such embodiments, the particles can be pressurized to a pressure of at least 50 psi, 60 psi, 70 psi, 80 psi, 90 psi, 100 psi, 110 psi, 120 psi, 130 psi, 140 psi, or 150 psi by mixing the particles with a high-pressure gas (e.g., air). The appropriate pressure level can be selected based on the properties of the material used to form the object (e.g., hardness, elastic limit), the initial surface properties of the object (e.g., initial surface roughness and / or porosity), the target surface properties of the object (e.g., target roughness and / or porosity), the type of medium used, the target processing time (e.g., higher pressure can allow for faster processing), and / or any other relevant considerations.

[0063] Before applying the medium to the object, it can be heated to a first elevated temperature (e.g., above room temperature). This method can be beneficial for promoting the mechanical deformation of materials with temperature-dependent properties (e.g., thermoplastics). The first elevated temperature can be based on the properties of the material used to form the object (e.g., glass transition temperature (T g ), melting point), the initial surface properties of the object (e.g., initial surface roughness and / or porosity), the target surface properties of the object (e.g., target roughness and / or porosity), the type of medium used, the target processing time (e.g., higher temperatures can allow for faster processing), and / or any other relevant considerations.

[0064] For example, the first elevated temperature can be greater than or equal to the T g of the material used to form the object. In some embodiments, the object is partially or fully made of a material with a T g of at least 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 175°C or 200°C; and the medium is heated to a temperature at least 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C or 50°C higher than the T g of the material. For example, the medium can be heated to a temperature in the range of 30°C to 250°C, or in the range of 50°C to 200°C, e.g., at least 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C or 190°C.

[0065] The first elevated temperature can be lower than the melting point of the material used to form the object. For example, the object can be partially or fully made of a material with a melting point less than or equal to 300°C, 275°C, 250°C, 225°C, 200°C, 175°C, 150°C, 125°C, 100°C or 75°C; and the medium can be heated to a temperature at least 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C or 50°C lower than the melting point of the material. In some embodiments, the medium is heated to a temperature not exceeding 250°C, 225°C, 200°C, 190°C, 180°C, 170°C, 160°C, 150°C, 140°C, 130°C, 120°C, 110°C, 100°C, 90°C or 80°C.

[0066] The medium can be partially or entirely composed of a thermally conductive material configured to enhance heat energy transfer to the surface of the object. For example, the medium can be partially or entirely composed of metals (e.g., stainless steel, aluminum, copper), ceramics (e.g., sialon (aluminum silicate oxynitride), silicon carbide), composite materials (e.g., polyimide composite materials), or suitable combinations thereof. In some embodiments, the medium is partially or entirely made of a material having a thermal conductivity in the range of 1 W / mK to 400 W / mK, such as a thermal conductivity of at least 50 W / mK, 100 W / mK, 150 W / mK, 200 W / mK, 250 W / mK, 300 W / mK, or 350 W / mK.

[0067] Other properties of the medium (e.g., hardness, size, shape, friability) can vary as needed and can be selected based on factors such as the type of material used to form the object (e.g., the hardness of the object), the target surface properties of the object (e.g., target roughness and / or porosity), reusability, cost, and / or environmental conditions (e.g., temperature, pressure). For example, the hardness of the medium (e.g., Mohs hardness) can be at least 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9, or 9.5. The medium can have a particle size in the range of 50 μm to 2 mm (e.g., average particle size), such as a particle size less than or equal to 1.5 mm, 1 mm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, or 100 μm. The shape of the medium can be angular, sub-angular, sub-rounded, or rounded. The friability of the medium can refer to its tendency to break during use and can correspond to reusability, as a more friable medium may have limited reusability or be non-reusable, while a less friable medium may be reusable. Reusability can be quantified in various ways, such as the number of times the medium can be reused during a surface modification process. For example, in some embodiments, the medium is suitable for at least 10 uses, 20 uses, 30 uses, 40 uses, 50 uses, 60 uses, 70 uses, 80 uses, 90 uses, or 100 uses.

[0068] The medium can be applied to any suitable part of the object, such as part or all of the outer surface of the object and / or part or all of the inner surface of the object. For example, in an embodiment where the object is a dental appliance configured to be worn on a patient's teeth, the medium can be applied to any of the following parts of the appliance: the buccal surface, the lingual surface, the occlusal surface, the surface configured to be positioned adjacent to or near the patient's teeth, the surface configured to be positioned adjacent to or near the patient's gums, the surface configured to be positioned adjacent to or near the patient's palate, the surface configured to be positioned adjacent to or near the patient's tongue, or a suitable combination thereof.

[0069] In some embodiments, while applying the medium, the object is rotated, translated, tumbled, vibrated, or otherwise moved so as to expose multiple different surfaces of the object to the medium. The motion can be applied via a drum (e.g., an agitated tumbler), a moving platform, a robotic arm, and / or any other suitable actuation mechanism. Alternatively, the object can be held in a fixed position and / or orientation such that only some of the object surfaces are exposed to the medium. This method allows specific surfaces to be selectively modified by the medium while other surfaces remain unmodified; and / or allows different modifications to be applied to different surfaces of the object.

[0070] At block 406, method 400 can optionally include adjusting the ambient temperature while applying the heating medium to the object. For example, the environment around the object can be heated to a second elevated temperature (e.g., above room temperature) to further enhance the mechanical deformation of the object surface and / or reduce the loss of system thermal energy. The second elevated temperature can be the same as the first elevated temperature of block 404 or can be different from the first elevated temperature (e.g., lower or higher than the first elevated temperature). For example, the second elevated temperature can be at least 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, or 50°C lower or higher than the first elevated temperature. In some embodiments, the second elevated temperature is in the range of 30°C to 100°C, e.g., a temperature of at least 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, or 100°C.

[0071] Optionally, the second elevated temperature can be selected based on the properties of the material used to form the object, the initial surface properties of the object, the target surface properties of the object, the type of medium used, the first elevated temperature to which the medium is heated, the target processing time, and / or any other relevant considerations. For example, the second elevated temperature can be greater than, equal to, or less than the T of the material g ; and / or can be below the melting point of the material. However, in other embodiments, the process in block 406 can be omitted such that the ambient temperature is uncontrolled or allowed to remain at the ambient temperature during processing.

[0072] After the processes of block 404 and / or 406, the surface characteristics of the object can be varied as needed according to the intended use of the object. For example, in some embodiments, the initial Ra of at least one surface of the object is at least 5 μm, 10 μm, 15 μm, or 20 μm; and the processes of block 404 and / or 406 are configured to reduce the Ra to no more than 10 μm, 5 μm, 4 μm, 3 μm, 2 μm, or 1 μm. As another example, the initial porosity of at least one surface of the object can be at least 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%; and the processes of block 404 and / or 406 are configured to reduce the porosity to no more than 1%, 0.75%, 0.5%, 0.25%, 0.1%, or 0.05%.

[0073] At block 408, method 400 can include collecting the medium for reuse. As discussed above, the medium can be a reusable medium having relatively low friability, such as metal or high-strength ceramic. In such embodiments, after applying the medium to the object, the medium can be collected for reuse in the same surface modification process or a subsequent surface modification process. Optionally, before reuse, the medium can be cleaned, filtered, mixed with fresh medium, and / or otherwise processed. However, in other embodiments, the process of block 408 can be omitted.

[0074] Method 400 can be modified in many different ways. For example, although the above steps of method 400 are described for a single object, method 400 can be used to process any suitable number of objects, such as dozens, hundreds, or thousands of additive manufactured objects, sequentially or simultaneously. In some embodiments, the object is associated with a single individual (e.g., a series of dental appliances for treating a single patient), while in other embodiments, the object can be associated with multiple individuals (e.g., a batch of dental appliances for multiple patients). As another example, Figure 4 The order of the illustrated processes can be varied. Some processes of method 400 can be omitted, e.g., the processes of block 406 and / or 408. Method 400 can also include Figure 4 additional processes not shown.

[0075] Figure 5A is a partial schematic view of a system 500 for processing one or more additive manufactured objects 502 according to an embodiment of the present technology. System 500 can be used to implement any method described herein, such as Figure 4 method 400. In addition, system 500 can be used in combination with any other system and device described herein. For example, system 500 can be Figure 3 a part of the surface modification subsystem 308.

[0076] System 500 includes a chamber 504 containing a container 506 configured to hold one or more objects 502 (e.g., one, two, three, four, five, 10, 20, 30, 40, 50 or more objects 502). The container 506 can be operably coupled to an actuator 508 (e.g., a motor) configured to actuate (e.g., rotate, translate, vibrate, agitate) the container 506 and the objects 502. For example, in the illustrated embodiment, the container 506 is configured as a drum that includes a barrel (also referred to herein as a “drum”) for holding the objects 502, and the actuator 508 is configured to rotate and / or vibrate the barrel. For example, the barrel can rotate at a speed of at least 1 RPM, 5 RPM, 10 RPM, 20 RPM, 30 RPM, 40 RPM or 50 RPM. The objects 502 can be loose within the barrel such that rotation and / or vibration of the barrel causes the objects 502 to tumble. This configuration can cause multiple or all surfaces of the objects 502 to be modified, as further described below. However, in other embodiments, the container 506 can be configured differently. For example, the container 506 can alternatively be a movable or fixed platform (e.g., a plate, a tray), and the objects 502 can be supported on the surface of the platform (e.g., fixed in a fixed position and / or orientation). This configuration can be used for cases where only certain object surfaces are to be modified and / or where different processing parameters are to be used to modify different object surfaces.

[0077] System 500 includes at least one applicator 510 (e.g., a nozzle) configured to direct a blasting medium 512 (e.g., a plurality of metal and / or ceramic particles) toward the objects 502 contained within the container 506. The applicator 510 can be connected to a source 514 of the blasting medium 512 (e.g., a hopper, a bucket, a reservoir or other container - as schematically shown). In some embodiments, the source 514 is pressurized such that the blasting medium 512 is propelled from the applicator 510 onto the objects 502 at a high enough pressure to cause mechanical deformation and / or wear of the object surfaces. For example, the pressure can be at least 50 psi, 60 psi, 70 psi, 80 psi, 90 psi, 100 psi, 110 psi, 120 psi, 130 psi, 140 psi or 150 psi. In some embodiments, the applicator 510 is a fixed device such that the blasting medium 512 is applied to the objects 502 from a single fixed direction. Alternatively, the applicator 510 can be movable (e.g., rotated and / or translated) such that the blasting medium 512 can be applied to the objects 502 from different directions.

[0078] Although Figure 5AA single filler 510 is shown, but in other embodiments, system 500 may include multiple fillers 510 (e.g., at least two, three, four, five, or more fillers 510) in different positions and / or orientations relative to container 506. For example, any filler 510 may be positioned at or near the upper portion, the bottom, or the sidewall of chamber 504. In such embodiments, some or all of the fillers 510 may be configured to apply the same type of abrasive media 512, or some or all of the fillers 510 may be configured to apply different types of abrasive media 512. In embodiments using multiple types of abrasive media 512, system 500 may include multiple media sources 514.

[0079] Source 514 may include or be coupled to at least one first heating element 516 configured to heat abrasive media 512 to a first elevated temperature. As previously described, the first elevated temperature may be in the range of 30°C to 250°C, or in the range of 50°C to 200°C, such as a temperature of at least 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, or 190°C. The first heating element 516 may be or include any suitable device, such as a heated fluid source, an induction heater (e.g., in embodiments where abrasive media 512 includes a metallic material), a thermoelectric heater, or a heat pump. The first heating element 516 may be thermally coupled to the source 514 of abrasive media 512 in various ways. For example, the first heating element 516 may be positioned within the source 514, attached to the outer wall of the source 514, thermally coupled to a fluid circulating within or near the source 514, etc. Although Figure 5A a single first heating element 516 is shown, but in other embodiments, system 500 may include multiple first heating elements 516 (e.g., two, three, four, five, or more first heating elements 516) that may be positioned at different locations relative to the source 514.

[0080] Optionally, system 500 may include a second heating element 518 configured to heat the environment within chamber 504 to a second elevated temperature. As previously described, the second elevated temperature may be the same as or different from the first elevated temperature. For example, the second elevated temperature may be in the range of 30°C to 100°C, such as at least 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, or 100°C. The second heating element 518 may be or include any suitable device, such as a heated fluid source, a thermoelectric heater, or a heat pump. Although the second heating element 518 is shown positioned within chamber 504 near the sidewall, in other embodiments, the second heating element 518 may be arranged differently. For example, the second heating element 518 may be positioned at different locations within chamber 504 (e.g., near the upper portion of chamber 504, near the lower portion of chamber 504), may be positioned outside of chamber 504, may be thermally coupled to the fluid circulating into chamber 504, etc. Additionally, although Figure 5A a single second heating element 518 is shown, in other embodiments, system 500 may include multiple second heating elements 518 (e.g., two, three, four, five, or more second heating elements 518), which may be positioned at different locations relative to chamber 504.

[0081] System 500 may include a controller 520 configured to control the operation of other components of system 500, for example, via one or more control signals. For example, controller 520 may be operably coupled to actuator 508, filler 510, media source 514, first heating element 516, and / or second heating element 518. Controller 520 may be or include a computing device that includes one or more processors and a memory that stores instructions for performing any of the following operations: controlling the actuation of container 506 via actuator 508 (e.g., rotational speed, rotational direction, vibration frequency, vibration amplitude); controlling the application of abrasive media 512 delivered via filler 510 (e.g., in terms of rate, amount, time point, pressurization); controlling the position and / or orientation of filler 510 via a corresponding actuator (not shown); controlling the temperature of abrasive media 512 via first heating element 516; and / or controlling the temperature of chamber 504 via second heating element 518.

[0082] For example, in some embodiments, controller 520 is configured to receive input data (e.g., from a human operator, a computing device, a database) characterizing object 502 to be processed, such as the type of object 502 (e.g., the type of dental appliance), the material used to form object 502 (e.g., material type; such as hardness, T g, material properties such as melting point), the technology used to form the object 502 (e.g., the type of additive manufacturing process), the initial properties of the object 502 (e.g., initial surface roughness and / or porosity), the target properties of the object 502 (e.g., target surface roughness and / or porosity), the target processing time, and / or other relevant information. Based on the input data, the controller 520 can determine a set of parameters for processing the object 502, such as the type of abrasive media 512 used, the pressure level for applying the abrasive media 512, the position and / or orientation of the applicator 510 during sandblasting, the first elevated temperature of the abrasive media 512, the second elevated temperature of the chamber 504, the actuation parameters of the container 506 (e.g., rotational speed, rotational direction, vibration frequency, vibration amplitude), and / or the amount of time for which the abrasive media 512 is to be applied. The appropriate parameters can be determined in various ways, such as being manually input by an operator; obtained from a database, lookup table, or other suitable data structure; and / or generated by an automated algorithm (e.g., a rule-based algorithm, a trained machine learning algorithm). Then, the controller 520 can initiate the processing of the object 502 according to the determined parameters.

[0083] Optionally, the system 500 can include one or more sensors (not shown) that are configured to provide monitoring and feedback during processing. For example, the system 500 can include at least one temperature sensor (e.g., thermocouple, thermistor, infrared camera) that is configured to measure the temperature of parts of the system 500. In some embodiments, one or more temperature sensors are located on or inside the chamber 504 (e.g., on the upper, lower, and / or side walls), on or inside the container 506, and / or on or inside the media source 514. The temperature measurements generated by the temperature sensors can be transmitted to the controller 520, and the controller 520 can adjust the heat output of the first heating element 516 and / or the second heating element 518 to maintain the abrasive media 512 and / or the chamber 504 within a desired temperature range, respectively.

[0084] As another example, the system 500 can include one or more load sensors (e.g., force sensor, weight sensor, torque sensor) that are configured to detect whether the container 506 has an excessive mechanical load (e.g., excessive force, excessive torque, or a combination thereof). The excessive mechanical load may be due to an excessive number of additional objects 502 within the container 506 and / or an excessive amount of abrasive media 512 retained within the container 506. The load data generated by the load sensors can be transmitted to the controller 520, and the controller 520 can adjust the operation of the container 506 accordingly, such as slowing down the movement speed (e.g., rotational speed) of the container 506 or stopping the movement of the container 506 if the detected load exceeds a threshold indicating the presence of an excessive mechanical load.

[0085] Other types of sensors that can be used to provide feedback to the controller 520 include, but are not limited to, pressure sensors, imaging devices (e.g., cameras), and motion sensors (e.g., accelerometers, gyroscopes). Based on the feedback, the controller 520 can adjust the operation of the various components of the system 500 (e.g., the actuator 508, the filler 510, the media source 514, the first heating element 516, and / or the second heating element 518).

[0086] In some embodiments, the system 500 further includes a collection device 522 (schematically shown), which is configured to collect the used abrasive media 512. The collected abrasive media 512 can be reused (e.g., for processing the same object 502 or a different group of objects), or it can be discarded. The collection device 522 can include a container (e.g., a tray, a reservoir, a hopper, etc.) configured to hold the abrasive media 512, and hoses, pipes, drain pipes, funnels, and / or other structures configured to transfer the abrasive media 512 into the container and / or to other locations in the system 500 (e.g., back to the media source 514). Additionally, the collection device can also include filters, traps, or similar components to separate the abrasive media 512 from debris and / or other contaminants. The abrasive media 512 can be directed into the container by gravity, vacuum pressure, and / or any other suitable technique. For example, in the illustrated embodiment, the collection device 522 is located at or near the bottom of the chamber 504, and the container 506 can include one or more apertures (e.g., holes, perforations) that allow the abrasive media 512 to fall out of the container 506 by gravity and towards the collection device 522. In other embodiments, the collection device 522 can be arranged differently (e.g., it can be located in a different part of the chamber 504, it can be part of another component (e.g., the container 506)), and / or other mechanisms can be used to direct the used abrasive media 512 into the collection device 522.

[0087] Figure 5B is a partial schematic view of a container 550 configured according to an embodiment of the present technology. The container 550 can be used in conjunction with any of the systems described herein. For example, the container 550 can be used as Figure 5A the container 506 of the system 500. The container 550 can be configured to hold one or more additive manufactured objects 502 (e.g., 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, or more objects 502). In the illustrated embodiment, the container 550 is configured as a drum or a bucket that includes an inner portion 552 and an outer portion 554. Both the inner portion 552 and the outer portion 554 can be actuated (e.g., rotated, translated, vibrated, agitated), or the inner portion 552 can be actuated while the outer portion 554 remains stationary.

[0088] The internal portion 552 can be an internal drum or barrel that houses the additive manufacturing object 502. The upper section of the internal portion 552 can be opened to allow the blasting medium 512 to be applied to the object 502 (e.g., via Figure 5A the filler 510), as described in other parts of this document. In some embodiments, the internal portion 552 is configured to allow the removal of excess blasting medium 512. For example, the internal portion 552 can include a plurality of perforations 556 sized to hold the object 502 within the internal portion 552 while allowing the blasting medium 512 to pass through. The blasting medium 512 can leave through the perforations 556 due to the blasting force, gravity, movement of the internal portion 522, or a combination thereof. Although Figure 5B the perforations 556 are depicted as being located in the sidewall of the internal portion 552, the perforations 556 can alternatively or additionally be located in other sections of the internal portion 552, such as in the bottom wall of the internal portion 552.

[0089] The external portion 554 can be an external drum or barrel that houses and surrounds the internal portion 552. In some embodiments, the external portion 554 is configured to collect the blasting medium 512 that has left the internal portion 552 (e.g., the external portion 554 can be Figure 5A a part of the collection device 522 of the system 500, or can replace the collection device 522). Thus, the external portion 554 may not include any perforations, or any perforations present in the external portion 554 can be smaller than the size of the blasting medium 512 to prevent the blasting medium 512 from leaving the external portion 554. Optionally, the external portion 554 can be coupled to a hose, pipe, discharge pipe, funnel, etc., which is configured to transfer the blasting medium 512 to another location, such as to a separate collection container (e.g., Figure 5A the collection device 522) or back to the medium source (e.g., Figure 5A the medium source 514).

[0090] In some embodiments, the container 550 is operably coupled to one or more load sensors that monitor whether there is an excessive mechanical load in the container 550 (e.g., in the internal portion 552 of the container 550). For example, if some or all of the blasting medium 512 applied to the object 502 does not leave through the perforations 556 of the internal portion 552 but remains within the internal portion 552, there may be an excessive mechanical load. As described herein, if an excessive mechanical load is detected, the operation of the container 550 can be adjusted (e.g., by slowing down or stopping the movement of the container 550).

[0091] Figure 6is a flowchart showing another method 600 for processing an object of additive manufacturing according to an embodiment of the present technology. Method 600 can be performed using any suitable system or device (e.g., the embodiments described below in conjunction with Figure 7A and Figure 7B . In some embodiments, some or all of the processes of method 600 are implemented as computer-readable instructions (e.g., program code) configured to be executed by one or more processors of a computing device. Method 600 can be combined with any other method described herein (e.g., Figure 1 's method 100 and / or Figure 4 's method 400).

[0092] Method 600 begins at block 602 by receiving an object of additive manufacturing. In some embodiments, the object is a dental appliance, such as an orthodontic appliance, a palatal expander, a retainer, etc. The object can be manufactured using any of the additive manufacturing techniques described herein and can be made of any suitable material or combination of materials, e.g., it can be made of any of the materials described previously with respect to Figure 4 block 402 of method 400. For example, in some embodiments, the object is made partially or entirely of a thermoplastic material. As another example, the object can be made partially or entirely of a thermosetting material (e.g., a thermosetting resin). The material can be a biocompatible material suitable for use on or within a patient's body.

[0093] At block 604, method 600 includes obtaining topography data of the surface of the object. The topography data can characterize the geometry of the object's surface (e.g., shape, contour, feature size). For example, in an embodiment where the object is an orthodontic appliance, the topography data can characterize the geometry of the appliance on the lingual surface, buccal surface, occlusal surface, palatal surface, inner surface, outer surface, upper surface, lower surface, side surface, or a suitable combination thereof. The topography data can be obtained using at least one sensor, such as one or more of the following sensor types: imaging devices (e.g., cameras, scanners), distance sensors (e.g., ultrasonic sensors, infrared sensors, time-of-flight sensors, rangefinders), or a combination thereof.

[0094] In some embodiments, the topography data includes or is used to determine the height profile or distribution of the object. The height of the object can be measured at one or more points on the object, along one or more lines on the object, and / or between one or more regions of the object. The height can be measured relative to a reference height (e.g., the height of a specified location on the object and / or on the substrate supporting the object).

[0095] At block 606, method 600 may optionally include obtaining data for at least one additional object characteristic. The additional characteristics may include any of the following: the type of the object (e.g., the type of a dental appliance), the geometry of the object (e.g., the object thickness, the locations of different functional parts), the type of material used to form the object, the characteristics of the material (e.g., T g , melting point), the locations of different materials in the object (in embodiments where the object is formed of multiple types of materials), and / or the initial surface characteristics of the object (e.g., initial roughness and / or porosity).

[0096] Data for the additional characteristics may be obtained in various ways. For example, data for the additional characteristics may be received from a database, a computing device or system (e.g., a server), or other suitable data sources. In some embodiments, the object has one or more customized characteristics (e.g., for a specific appliance type, patient, treatment stage, etc.), and the process of block 606 further includes receiving a unique identifier of the object and then obtaining data for the customized characteristics based on the identifier. For example, the identifier may be received from a label, a marker (e.g., an RFID marker), a code (e.g., a barcode), etc., associated with the object (e.g., embedded in the object or attached to the object, embedded in a substrate or other structure supporting the object or attached to the substrate or other structure). The identifier may be determined using a suitable sensor (e.g., an RFID reader, a barcode scanner, etc.). Then, the identifier may be used to locate and obtain data for the customized characteristics of the object, locate and obtain data for the customized characteristics of the object from a database, a server, or other suitable data sources.

[0097] Alternatively or in combination, other techniques may be used to obtain the additional characteristics. For example, some or all of the additional characteristics may be determined based on sensor data from one or more sensors (e.g., an imaging device, an optical sensor, a chemical sensor, etc.). In such embodiments, the sensor may be the same as the sensor used to obtain the topography data in block 604 or may be a different sensor. Optionally, data for the additional characteristics may be provided via an input by a human operator.

[0098] At block 608, method 600 includes modifying the surface of an object by applying heat to the object. The heat can soften and / or melt the material at or near the surface of the object to change surface properties, such as by reducing surface roughness, sealing surface pores, etc. The degree of softening and / or melting can be deep enough to produce the desired surface modification, but not so deep as to adversely affect the macroscopic structure and / or mechanical properties of the object. For example, the object can be softened and / or melted to a depth of at least 5μm, 10μm, 20μm, 30μm, 40μm or 50μm; and / or not more than 100μm, 75μm, 50μm or 25μm. In some embodiments, the depth of softening and / or melting (also referred to herein as the "treatment depth") can be substantially uniform over the entire modified surface of the object (e.g., the variation in treatment depth does not exceed 10%, 5% or 1%). Alternatively, the treatment depth can vary over the surface of the object, e.g., the treatment depth of some portions of the surface can be greater than that of other portions. The treatment depth can be selected based on the target surface properties of each object portion, the material composition of each object portion, the intended function of each object portion, and / or any other suitable factors.

[0099] Any suitable heating element (e.g., a flame generator, a plasma generator, a corona generator, etc.) can be used to apply the heat. The heating element can be configured to heat the surface of the object and / or the portion of the object near the surface to a target temperature (e.g., a maximum temperature, a minimum temperature, and / or an average temperature). The target temperature can be selected based on the properties of the material used to form the object (e.g., T g , melting point), the initial surface properties of the object (e.g., initial surface roughness and / or porosity), the target surface properties of the object (e.g., target roughness and / or porosity), the type of medium used, the target treatment time (e.g., a higher temperature can allow for a faster treatment), and / or any other relevant considerations.

[0100] For example, the target temperature can be greater than or equal to the T g of the material used to form the object. In some embodiments, the object is partially or fully made of a material with a T g of at least 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 175°C or 200°C; and the target temperature is higher than the T gAt least 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C or 50°C higher. Alternatively or in combination, the object can be partially or wholly made of a material having a melting point greater than or equal to 75°C, 100°C, 125°C, 150°C, 175°C, 200°C, 225°C, 250°C, 275°C or 300°C. The target temperature can be at least 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C or 50°C higher or lower than the melting point of the material. In some embodiments, the target temperature is in the range of 30°C to 250°C, or in the range of 50°C to 300°C, such as a temperature of at least 75°C, 100°C, 125°C, 150°C, 175°C, 200°C, 225°C, 250°C or 275°C.

[0101] Heat can be applied to any suitable part of the object, such as part or all of the outer surface of the object and / or part or all of the inner surface of the object. For example, in an embodiment where the object is a dental appliance configured to be worn on a patient's tooth, heat can be applied to any of the following parts of the appliance: the buccal surface, the lingual surface, the occlusal surface, the surface configured to be positioned adjacent to or close to the patient's tooth, the surface configured to be positioned adjacent to or close to the patient's gum, the surface configured to be positioned adjacent to or close to the patient's palate, the surface configured to be positioned adjacent to or close to the patient's tongue, or a suitable combination thereof. In embodiments where multiple object surfaces are to be treated, heat can be applied to these surfaces sequentially or simultaneously. Optionally, certain surfaces of the object can be selectively heated while other surfaces are not heated and thus remain unmodified.

[0102] Heat can be applied to the object based on the topography data of block 604 and / or additional object characteristics of block 606. For example, heating parameters (e.g., the position and / or orientation of the heating element relative to the object surface, the output of the heating element, the activation of the heating element) can be adjusted based on the local surface topography and / or other object characteristics to control the degree of surface modification. In some embodiments, the heating element is configured to apply heat to only a specific part (e.g., a point, a line or a region) of the object surface at a time, and the vertical position of the heating element is adjusted according to the height of the corresponding object part to control the distance between the heating element and the object surface. Depending on the desired treatment depth, the material composition of the object, the intended function of the object, the target distribution of the surface characteristics, etc., this distance can be fixed or variable.

[0103] Alternatively or in combination, the output (e.g., intensity, flame size) of the heating element can vary according to the height and / or other characteristics of the object portion. For example, a higher heat intensity and / or a larger flame size can be used to process an object portion that is relatively low in height, relatively thick, and / or made of a material with a relatively high melting point. Conversely, a lower heat intensity and / or a smaller flame size can be used to process an object portion that is relatively high in height, relatively thin, and / or made of a material with a relatively low melting point. The adjustment of the heating element output can be selected based on the desired processing depth, the material composition of the object, the intended function of the object, the target distribution of surface characteristics, etc.

[0104] The surface characteristics of the object after the process of block 608 can vary as desired depending on the intended use of the object. For example, in some embodiments, the initial Ra of at least one surface of the object is at least 5 μm, 10 μm, 15 μm, or 20 μm; and the process of block 608 is configured to reduce the Ra to no more than 10 μm, 5 μm, 4 μm, 3 μm, 2 μm, or 1 μm. As another example, the initial porosity of at least one surface of the object can be at least 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%; and the process of block 608 is configured to reduce the porosity to no more than 1%, 0.75%, 0.5%, 0.25%, 0.1%, or 0.05%.

[0105] In some embodiments, the surface properties of the object are substantially uniform (e.g., vary by no more than 10%). However, in other embodiments, certain portions of the object may have different properties (e.g., different roughness, porosity, depth of treatment) than other portions of the object, depending on the heating parameters used. For example, the object may include two, three, four, five, six, seven, eight, nine, ten, or more object portions having different surface properties. The distribution of surface properties can be selected based on the function of each object portion (e.g., whether the portion will contact the patient's teeth, gums, palate, and / or tongue; whether the portion will be visible when worn), the material composition of each object portion, and / or any other suitable considerations.

[0106] Method 600 may be modified in many different ways. For example, although the above steps of method 600 are described with respect to a single object, method 600 may be used to process any suitable number of objects, such as dozens, hundreds, or thousands of additively manufactured objects, sequentially or simultaneously. As another example, Figure 6 The order of the processes shown may be changed. Some processes of method 600 (e.g., the process of block 606) may be omitted. Method 600 may also include Figure 6Additional processes not shown in the figure. For example, the heating applied in block 608 can be configured to achieve other functions, such as burning and / or removing sacrificial materials (e.g., supports) that are not intended to be present in the final product.

[0107] Figure 7A is a partial schematic view of a system 700a for processing an additive manufacturing object 702 according to an embodiment of the present technology. The system 700a can be used to implement any method described herein, such as Figure 6 method 600. In addition, the system 700a can be used in combination with any other systems and devices described herein. For example, the system 700a can be Figure 3 part of the surface modification subsystem 308.

[0108] can receive the object 702 from an additive manufacturing system (not shown) and position it on a conveyor belt 704 or other suitable mechanism, which is configured to transport the object 702 through various sections of the system 700a. The object 702 can be placed on the conveyor belt 704 in a random position and / or orientation, or in a predetermined position and / or orientation. Optionally, the object 702 can be positioned on a substrate (e.g., carrier, tray, build platform) placed on the conveyor belt 704.

[0109] The conveyor belt 704 can first transport the object 702 to a sensing area 706 adjacent to or near at least one sensor 708. The sensor 708 can be configured to generate topography data of the object 702, as described in block 604 of Figure 6 method 600 above. For example, the sensor 708 can be configured to measure the height of the surface of the object 702 at one or more positions (e.g., at multiple discrete points, along a line, within an area). The height can be measured relative to a reference position on the object 702, relative to the surface of the conveyor belt 704, and / or relative to the surface of the substrate supporting the object 702 on the conveyor belt 704. Optionally, the height can be determined by measuring the distance between the object 702 and the sensor 708.

[0110] The sensor 708 can include an imaging device, a distance sensor, or any other type of sensor suitable for measuring the 3D topography of the surface of the object 702. Although Figure 7A the embodiments of

[0111] Subsequently, conveyor belt 704 can transport object 702 to a processing area 710 adjacent to or near heating element 712. Heating element 712 can be configured to apply heat to object 702 to modify the surface properties of object 702 according to the techniques described in method 600 above with respect to Figure 6 . For example, as Figure 7A shown, heating element 712 is configured as a multi-stage flame generator that outputs multiple flames 714a - 714d (collectively referred to as "flames 714"). Although Figure 7A four flames 714 are shown, in other embodiments, heating element 712 can output a different number of flames 714, such as two, three, five, six, seven, eight, nine, ten, or more flames 714.

[0112] The flames 714 can be horizontally spaced apart from each other such that each flame applies heat to a different portion of the surface of object 702. For example, in the illustrated embodiment, the first flame 714a is configured to heat a first surface portion 716a of object 702, the second flame 714b and the third flame 714c are configured to heat a second surface portion 716b of object 702, and the fourth flame 714d is configured to heat a third surface portion 716c of object 702. The horizontal distance between the first flame 714a and the last flame 714d can be the same as or similar to (e.g., within 10%) the length of object 702, such that the entire length of object 702 can be heated without horizontally moving (e.g., along the direction of movement of conveyor belt 704) heating element 712 and / or object 702. Alternatively, the horizontal distance between the first flame 714a and the last flame 714d can be less than the length of object 702. In such an embodiment, the surface of object 702 can be sequentially heated by horizontally moving object 702 relative to heating element 712 via conveyor belt 704 and / or by horizontally moving heating element 712 relative to object 702.

[0113] The operating parameters (e.g., activation, intensity, direction, size) of each flame 714 can be independently controlled. For example, each flame 714 can be independently turned on and off. As another example, the intensity of each flame 714 can also be independently adjusted to provide a desired degree of heating, as discussed in more detail below. In the illustrated embodiment, each flame 714 is directed towards the surface of object 702 in the vertical direction. In other embodiments, some or all of the flames 714 can be directed differently. Additionally, the direction of each flame 714 can be fixed or variable.

[0114] The flame height, flame width (e.g., measured orthogonally to the direction of movement of the conveyor belt 704), and / or flame depth (e.g., measured along the direction of movement of the conveyor belt 704) can also be controlled independently for each flame 714. In some embodiments, the width of some or all of the flames 714 is the same as or similar to (e.g., within 10%) the width of the object 702 and / or the conveyor belt 704, such that the entire width of the object 702 can be heated without laterally (e.g., in a direction orthogonal to the direction of movement of the conveyor belt 704) moving the object 702 and / or the heating element 712. Alternatively, the width of some or all of the flames 714 can be less than the width of the object 702. In such embodiments, the flames 714 can be arranged in a 2D array, and / or the heating element 712 can be movable in the lateral direction to provide heating along the entire width of the object 702.

[0115] The heating applied by the heating element 712 can be adjusted based on the topography data generated by the sensor 708, as described previously with respect to Figure 6 method 600. For example, the operating parameters of each flame 714 can be controlled based on the topography data to provide substantially uniform heating of the object surface. In some embodiments, the flame height is adjusted according to the height of the corresponding portion of the object surface so that each portion receives the same or similar degree of heating. The height of each flame 714 can be selected such that the tip of each flame 714 contacts or approaches the corresponding surface portion of the object 702. For example, a longer flame height is used for a lower surface portion, and a shorter flame height is used for a higher surface portion. For example, in the illustrated embodiment, the object 702 includes a plurality of surface portions having different heights. For example, the first surface portion 716a has a first surface height, the second surface portion 716b has a second surface height greater than the first surface height, and the third surface portion 716c has the first surface height. Thus, the first flame 714a can have a first flame height, the second flame 714b and the third flame 714c can have a second flame height less than the first flame height, and the fourth flame 714d can have the first flame height. However, in other embodiments, the operating parameters of each flame 714 can be configured to apply non-uniform heating to the object surface, for example, in cases where the object 702 includes different material types, requires non-uniform surface modification, etc.

[0116] System 700a may include a controller 718 configured to monitor and control various operations described herein, for example, via one or more control signals. The controller 718 may be or include a computing device that includes one or more processors and a memory that stores instructions for controlling the operation of the system 700a. For example, the controller 718 may be operably coupled to the conveyor belt 704 to control the moving speed and / or moving direction of the conveyor belt 704. The controller 718 may also be operably coupled to the sensor 708 to transmit instructions (e.g., instructions for acquiring the topography data of the object 702) to the sensor 708 and receive the topography data generated by the sensor 708. The controller 718 may also be operably coupled to the heating element 712 to control the operating parameters of the flame 714, such as described elsewhere herein, based on, for example, the topography data from the sensor 708 and / or data of additional characteristics of the object 702.

[0117] In the illustrated embodiment, the object 702 is placed on the conveyor belt 704 such that a single surface (e.g., the upper surface) of the object 702 is oriented towards and exposed to the sensor 708 and the heating element 712. Thus, a single surface of the object 702 can be processed by the system 700a in a single cycle. To process other surfaces of the object 702 (e.g., the bottom surface and / or the side surfaces), the system 700a may include means configured to flip or otherwise change the orientation of the object 702, such as a flipper, a robotic arm, etc. The means may be located after the processing area 710 to receive and reorient each object 702 after heating. Then, the flipped object 702 can return to the start of the conveyor belt 704 to process the newly exposed surface. This sequence can be repeated until all desired surfaces have been processed.

[0118] In other embodiments, the system 700a may include means configured to reorient the object 702 in the sensing area 706 and / or the processing area 710 to expose multiple surfaces for sensing and / or heating, respectively. Alternatively or in combination, the sensor 708 and / or the heating element 712 may be moved relative to the object 702 to sense and / or heat multiple surfaces, respectively. Optionally, the sensor 708 and / or the heating element 712 may be configured to sense and / or heat multiple surfaces of the object 702 without moving the object 702, the sensor 708, and / or the heating element 712. These techniques can be used to process multiple surfaces of the object 702 by the system 700a in a single cycle.

[0119] Figure 7A The system 700a in may be modified in many ways. For example, although Figure 7ASystem 700a is illustrated and described with respect to a single object 702, but system 700a can be used to process any suitable number of objects 702, such as dozens, hundreds, or thousands of objects 702, sequentially or simultaneously. As another example, system 700a can include Figure 7A additional components not shown in Figure 7A , such as additional sensors for monitoring and / or providing feedback in other parts of system 700a (e.g., within or after processing zone 710).

[0120] Figure 7B is a partial schematic view of another system 700b for processing object 702 according to an embodiment of the present technology. System 700b can be generally similar to Figure 7A system 700a, except that processing zone 710 includes a movable heating element 720 configured to output a flame 722. The movable heating element 720 can be coupled to an actuating device (e.g., a robotic arm, gimbal, linear and / or rotary actuator) that allows the movable heating element 720 to be moved to multiple different postures (e.g., positions and / or orientations) relative to object 702. Adjustment of the movable heating element 720 can be based on the topography data obtained by sensor 708 and / or data of additional object characteristics as described above.

[0121] For example, in the illustrated embodiment, the movable heating element 720 is translatable in the vertical direction such that the distance between the flame 722 and the object 702 can be adjusted as the object 702 travels past the flame 722 via conveyor 704. The height of the movable heating element 720 can be adjusted according to the height of the currently heated portion of the object surface such that each portion receives the same or similar degree of heating. Specifically, the height of the movable heating element 720 can be controlled such that the tip of the flame 722 contacts or approaches the corresponding surface portion of the object 702. For example, for a lower surface portion, the movable heating element 720 moves lower, while for a higher surface portion, the movable heating element 720 moves higher. For example, in the illustrated embodiment, when processing the first surface portion 716a and the third surface portion 716c, the movable heating element 720 can be moved to a first height; when processing the second surface portion 716b, the movable heating element 720 can be moved to a higher second height. However, in other embodiments, the height of the movable heating element 720 can be adjusted to, for example, apply non-uniform heating to the object surface in cases where the object 702 includes different material types, desired non-uniform surface modification, etc. Additionally, when adjusting the movable heating element 720, the flame 722 can be maintained at a fixed size and / or intensity, or the size and / or intensity of the flame 722 can be changed along with the adjustment of the movable heating element 720.

[0122] Optionally, the movable heating element 720 can be moved in other directions (e.g., laterally, horizontally, rotationally, etc.) to heat other surfaces of the object 702. Additionally, although the system 700b is shown as including a single movable heating element 720 configured to output a single flame 722, in other embodiments, the system 700b can include any suitable number of movable heating elements 720 (e.g., two, three, four, five, or more movable heating elements 720), and each movable heating element can output any suitable number of flames 722 (e.g., one, two, three, four, five, or more flames 722).

[0123] Figure 8A is a perspective view of a palatal expander 800 configured according to an embodiment of the present technology. The palatal expander 800 (also referred to herein as a "palatal expander" or "arch expander") can be manufactured and processed using the techniques described herein. For example, the palatal expander 800 can be made of a biocompatible material (e.g., nylon) via additive manufacturing. The palatal expander 800 includes an expander portion 802 configured to be positioned near the patient's palate and a pair of tooth engaging portions 804a, 804b coupled to opposite sides of the expander portion 802. Each tooth engaging portion 804a, 804b can include a plurality of tooth receiving cavities. For example, the tooth engaging portions 804a, 804b can be configured to receive three posterior teeth on each side of the patient's mouth.

[0124] The expander portion 802 can have an arch shape similar to the shape of the patient's palate and can include an upper surface 805a and a lower surface 805b opposite the upper surface 805a. The height of the expander portion 802 can be configured such that when the palatal expander 800 is worn, there is a gap between the upper surface 805a of the expander portion 802 and the patient's palate. Alternatively, the upper surface 805a of the expander portion 802 can be configured to contact the palate when worn.

[0125] In some embodiments, the upper surface 805a of the expander portion 802 matches the topography of the patient's palate, e.g., including any grooves, ridges, depressions, etc. present in the patient's specific anatomy. Compared to the upper surface, the lower surface 805b of the expander portion 802 facing the patient's tongue can have a different surface topography. For example, the lower surface 805b can be smoother than the upper surface 805a to increase comfort and / or avoid interfering with speech. In some embodiments, the lower surface 805b does not have the grooves, ridges, depressions, etc. present on the upper surface 805a, and / or can be substantially free of perceptible protrusions, bumps, and / or depressions.

[0126] During use, the expander portion 802 can apply a force against the teeth on opposite sides of the patient's mouth to cause palatal expansion of the patient. Specifically, the engagement between the expander portion 802 and the tooth engagement portions 804a, 804b can apply a force against the received teeth, which increases the size of the palate when the patient wears it. In some embodiments, the expander portion 802 has different properties than the tooth engagement portions 804a, 804b in order to apply sufficient force to widen the palate. For example, the expander portion 802 can have a higher T g and / or greater thickness.

[0127] A series of palatal expanders 800 can be used, and the series of palatal expanders 800 are incrementally staged to expand the patient's palate, e.g., by gradually increasing the width of the expander portion 802 according to the desired palate width for the corresponding treatment stage. For example, a series of palatal expanders 800 can expand the patient's palate from an initial arrangement (e.g., an initial width) to a target arrangement (e.g., a target width), where each palatal expander 800 is used to incrementally expand the palate from a corresponding first arrangement (e.g., a first palate width) towards a corresponding second arrangement (e.g., a second palate width). During use, each palatal expander 800 can be worn for a period of time and then replaced with the next expander in the series. This process can be repeated until the desired palatal expansion is achieved. Optionally, a series of palatal expanders 800 can include passive braces (e.g., retainers) that are configured to hold the patient's palate at the desired width, e.g., after treatment is complete. Additional details of palatal expanders suitable for use with the present technology are described in U.S. Patent No. 10,959,810 and U.S. Patent No. 11,273,011, the disclosures of each of which are incorporated herein by reference in their entirety.

[0128] Figure 8B Shown is surface modification of the palatal expander 800 using the heating element 806 according to an embodiment of the present technology. The heating element 806 can be implemented as part of any of the systems and devices described herein (e.g., Figure 7A system 700a), and can be generally similar to Figure 7A heating element 712.

[0129] The heating element 806 is configured to output a plurality of flames 808a–808g (collectively referred to as "flames 808"). Although Figure 8BSeven flames 808 are shown, but in other embodiments, the heating element 806 may produce a different number of flames 808 (e.g., one, two, three, four, five, six, eight, nine, ten, or more flames 808). Each flame 808 is configured to heat a different portion of the upper surface 805a of the palatal expander 800. For example, flames 808a and 808b are configured to heat the tooth engagement portions 804a, and flames 808c–808e are configured to heat the expander portion 802, and flames 808f and 808g are configured to heat the tooth engagement portions 804b.

[0130] The parameters of each flame 808 can be adjusted to produce a desired degree of heating of the corresponding portion of the palatal expander 800. For example, as Figure 8B shown, the height of each flame 808 can vary according to the height of the corresponding portion of the palatal expander 800 (e.g., flames 808b and 808f heat the lowest portion of the palatal expander 800 and thus have the longest flame height; flame 808d heats the highest portion of the palatal expander 800 and thus has the shortest flame height; flames 808a, 808c, 808e, and 808g heat the intermediate portions of the palatal expander 800 and thus have a medium flame height). This method can be used to produce a substantially uniform treatment depth on the surface 805a of the palatal expander 800.

[0131] In addition, the intensity of each flame 808 can be adjusted based on the thickness of the corresponding portion of the palatal expander 800 (e.g., flames 808c–808e heat the thicker expander portion 802 and thus have a higher intensity; flames 808a, 808b, 808f, and 808g heat the thinner tooth engagement portions 804a, 804b and thus have a lower intensity). This method can reduce the adverse effects on the mechanical integrity of the palatal expander 800 due to over-softening and / or melting.

[0132] Figure 8C Shown is surface modification of the palatal expander 800 using a movable heating element 810 according to an embodiment of the present technology. The movable heating element 810 can be implemented as part of any system and device described herein (e.g., Figure 7B system 700b), and can be generally similar to Figure 7B the movable heating element 720.

[0133] The movable heating element 810 is configured to output at least one flame 812. The palatal expander 800 can travel horizontally past the movable heating element 810 such that the flame 812 sequentially heats different portions of the palatal expander 800. While Figure 8CA single flame 812 is shown, but in other embodiments, the movable heating element 810 can produce different numbers of flames 812 (e.g., two, three, four, five, six, eight, nine, ten, or more flames 812).

[0134] The vertical height of the movable heating element 810 can be adjusted based on the height of the currently heated portion of the palatal expander 800. For example, as Figure 8C shown, during the first stage 814, the flame 812 heats a portion of the palatal expander 800 having a moderate height (e.g., the buccal side of the tooth engagement portion 804b), and the movable heating element 810 is in a first vertical position. During the second stage 816, the flame 812 heats a lower portion of the palatal expander 800 (e.g., the lingual side of the tooth engagement portion 804b), and the movable heating element 810 is in a second vertical position lower than the first vertical position. During the third stage 818, the flame 812 heats a higher portion of the palatal expander 800 (e.g., the expander portion 802), and the movable heating element 810 is in a third vertical position higher than the first and second vertical positions.

[0135] Optionally, the parameters of the flame 812 can also vary. For example, during the first stage 814 and the second stage 816, the flame 812 can have a lower intensity to avoid overheating the relatively thin tooth engagement portion 804b. During the third stage 818, the flame 812 can have a higher intensity to ensure sufficient heating of the relatively thick expander portion 802. III. Dental Appliances and Associated Methods

[0136] Figure 9A A representative example of a tooth repositioning appliance 900 configured in accordance with an embodiment of the present technology is shown. Any of the systems, methods, and devices described herein can be used to fabricate and post-process the appliance 900. The appliance 900 (also referred to herein as an "orthodontic appliance") is capable of being worn by a patient to effect progressive repositioning of the individual teeth 902 in the jaw. The appliance 900 can include a housing having tooth receiving cavities (e.g., a continuous polymeric housing or a segmented housing) that receive and elastically reposition the teeth. The appliance 900 or portions thereof can be indirectly fabricated using a physical model of the teeth. For example, a physical model of the teeth and a suitable polymeric material laminate can be used to form the appliance (e.g., a polymeric appliance). In some embodiments, for example, additive manufacturing techniques are used to directly fabricate the physical appliance from a digital model of the appliance.

[0137] Appliance 900 can be adapted to all teeth present in the upper or lower jaw, or to fewer than all teeth. Appliance 900 can be specifically designed to accommodate the patient's teeth (e.g., the topography of the tooth-receiving cavities matches the topography of the patient's teeth), and can be manufactured based on a positive or negative mold of the patient's teeth generated by impression, scanning, etc. Alternatively, appliance 900 can be a general-purpose appliance configured to receive teeth, but not necessarily shaped to match the topography of the patient's teeth. In some cases, only certain teeth received by appliance 900 are repositioned by appliance 900, while other teeth can provide a base or anchoring region for holding the appliance in place when appliance 900 exerts a force on one or more teeth that are the target of repositioning. In some cases, some, most, or even all teeth can be repositioned at some point during treatment. The teeth that are moved can also serve as a base or anchor for holding the appliance when the patient wears the appliance. In a preferred embodiment, no wires or other devices are provided for holding appliance 900 in the proper position on the teeth. However, in some cases, it may be desirable or necessary to provide separate attachments 904 or other anchoring elements on teeth 902 that have corresponding receptacles 906 or holes in appliance 900 such that appliance 900 can exert a selected force on the teeth. Representative examples of appliances, including those used in the systems, are described in a number of patents and patent applications assigned to Align Technology, Inc., including, for example, U.S. Patent Nos. 6,450,807 and 5,975,893, and on the company's website accessible on the World Wide Web (e.g., see the url “invisalign.com”). Examples of tooth-mounted attachments suitable for use with orthodontic appliances are also described in patents and patent applications assigned to Align Technology, Inc., including, for example, U.S. Patent Nos. 6,309,215 and 6,830,450.

[0138] Figure 9BFIG. 910 shows a tooth repositioning system 910 including a plurality of appliances 912, 914, 916 in accordance with an embodiment of the present technology. Any appliance described herein may be designed and / or provided as part of a set of a plurality of appliances for use in a tooth repositioning system. Each appliance may be configured such that the tooth receiving cavity has a geometry corresponding to an intermediate or final tooth alignment intended for the appliance. By placing a series of progressive position adjustment appliances on a patient's teeth, the patient's teeth can be gradually repositioned from an initial tooth alignment to a target tooth alignment. For example, the tooth repositioning system 910 may include: a first appliance 912 corresponding to an initial tooth alignment; one or more intermediate appliances 914 corresponding to one or more intermediate alignments; and a final appliance 916 corresponding to a target alignment. The target tooth alignment may be a planned final tooth alignment selected for the patient's teeth at the end of all planned orthodontic treatment. Alternatively, the target alignment may be one of some intermediate alignments for the patient's teeth during orthodontic treatment, which may include a variety of different treatment scenarios, including but not limited to cases where surgery is recommended, cases where interproximal reduction (IPR) is appropriate, cases where progress checks are scheduled, cases where anchorage placement is optimal, cases where palatal expansion is desired, cases involving restorative dentistry (e.g., inlays, onlays, crowns, bridges, implants, veneers, etc.). Thus, it should be understood that the target tooth alignment may be any planned resultant alignment for the patient's teeth following one or more progressive repositioning phases. Similarly, the initial tooth alignment may be any initial alignment of the patient's teeth, followed by one or more progressive repositioning phases.

[0139] Figure 9CIllustrated is a method 920 of orthodontic treatment using multiple appliances according to an embodiment of the present technology. Method 920 can be practiced using any appliance or group of appliances described herein. In block 922, a first orthodontic appliance is applied to a patient's teeth to reposition the teeth from a first tooth alignment to a second tooth alignment. In block 924, a second orthodontic appliance is applied to the patient's teeth to reposition the teeth from the second tooth alignment to a third tooth alignment. Method 920 can be repeated with any suitable number of sequential appliances and combinations of sequential appliances as needed to progressively reposition the patient's teeth from an initial alignment to a target alignment. The appliances can all be generated at the same stage or in groups or batches (e.g., at the start of a treatment phase), or the appliances can be manufactured one at a time and the patient can wear each appliance until the pressure of each appliance on the teeth can no longer be felt or until the maximum amount of expressed tooth movement for that given stage has been achieved. Multiple different appliances (e.g., a set) can be designed and even manufactured before the patient wears any of the multiple appliances. After wearing an appliance for an appropriate period of time, the patient can replace the current appliance with the next appliance in the series until there are no more appliances. The appliances are generally not fixed to the teeth, and the patient can place and replace the appliances at any time during the procedure (e.g., patient-removable appliances). The final appliance or appliances in the series can have one or more geometries selected to overcorrect the tooth alignment. For example, one or more appliances can have geometries that would (if fully achieved) move individual teeth beyond the tooth alignment that has been selected as "final". Such overcorrection may be desirable to counteract potential regression after the repositioning method has terminated (e.g., allowing individual teeth to move back toward their pre-correction positions). Overcorrection can also be beneficial for accelerating the correction rate (e.g., an appliance with a geometry positioned beyond the desired intermediate or final position can move individual teeth toward that position at a greater rate). In such cases, the use of the appliance can be terminated before the teeth reach the position defined by the appliance. Additionally, overcorrection can be intentionally applied to compensate for any inaccuracies or limitations of the appliance.

[0140] Figure 10 Illustrated is a method 1000 for designing an orthodontic appliance according to an embodiment of the present technology. Method 1000 can be applied to any embodiment of the orthodontic appliance described herein. Some or all of the steps of method 1000 can be performed by any suitable data processing system or device (e.g., one or more processors configured with suitable instructions).

[0141] In block 1002, a movement path for moving one or more teeth from an initial alignment to a target alignment is determined. The initial alignment can be determined, for example, from a mold or scan of a patient's teeth or oral tissues using techniques such as wax bite registration, direct contact scanning, x-ray imaging, tomography, ultrasound imaging, and other techniques for obtaining information about the position and structure of teeth, jaws, gums, and other orthodontically relevant tissues. A digital data set representing the initial (e.g., pre-treatment) alignment of the patient's teeth and other tissues can be obtained from the acquired data. Optionally, the initial digital data set is processed to segment the tissue components from one another. For example, data structures can be generated that digitally represent individual crowns. Advantageously, a digital model of the entire tooth can be generated, including measured or inferred hidden surfaces and root structures as well as surrounding bone and soft tissue.

[0142] The target alignment of the teeth (e.g., the desired and expected final outcome of orthodontic treatment) can be received from a clinician in the form of a prescription, can be calculated based on fundamental orthodontic principles, and / or can be inferred computationally based on a clinical prescription. By specifying the desired final positions of the teeth and a digital representation of the teeth themselves, the final position and surface geometry of each tooth can be specified to form a complete model of the tooth alignment at the end of the desired treatment.

[0143] Having both the initial and target positions of each tooth, a movement path can be defined for the movement of each tooth. In some embodiments, the movement path is configured to move the teeth with the fewest number of back-and-forth movements in the fastest way possible to bring the teeth from their initial positions to their desired target positions. Optionally, the tooth paths can be segmented, and the segments can be calculated such that the movement of each tooth within a segment remains within threshold limits of linear translation and rotational translation. In this way, the endpoints of each path segment can constitute a clinically viable repositioning, and the set of segment endpoints can constitute a clinically viable sequence of tooth positions such that moving from one point in the sequence to the next does not cause the teeth to collide.

[0144] In block 1004, a force system for generating the movement of one or more teeth along the movement path is determined. The force system can include one or more forces and / or one or more torques. Different force systems can result in different types of tooth movement, such as tipping, translation, rotation, extrusion, intrusion, root movement, etc. Biomechanical principles, modeling techniques, force calculation / measurement techniques, etc. (including knowledge and methods commonly used in orthodontics) can be used to determine the appropriate force system to apply to the teeth to achieve tooth movement. When determining the force system to apply, sources can be considered, including the literature, force systems determined experimentally or through virtual modeling, computer-based modeling, clinical experience, minimization of unwanted forces, etc.

[0145] The determination of the force system can be carried out in a variety of ways. For example, in some embodiments, the force system is determined on a patient-by-patient basis, such as using patient-specific data for determination. Alternatively or in combination, the force system can be determined based on a generalized model of tooth movement (e.g., based on experiments, modeling, clinical data, etc.), such that patient-specific data is not necessarily used. In some embodiments, the determination of the force system involves calculating specific force values to be applied to one or more teeth to produce a specific movement. Or, the determination of the force system can be carried out at a high level without calculating the specific force values of the teeth. For example, block 1004 can involve determining a specific type of force to be applied (e.g., extrusion force, intrusion force, translational force, rotational force, tipping force, torsional force, etc.) without calculating the specific magnitude and / or direction of the force.

[0146] The determination of the force system can include constraints on the allowable forces, such as the allowable directions and magnitudes and the desired movements brought about by the applied forces. For example, when manufacturing a palatal expander, different patients may require different movement strategies. For example, the amount of force required to separate the palate can depend on the age of the patient, as very young patients may not have fully formed sutures. Thus, in adolescent patients with an incompletely closed palatal suture and others, palatal expansion can be accomplished with a lower force magnitude. Slower palatal movement can also help the growing bone to fill the expanded suture. For other patients, a more rapid expansion may be required, which can be achieved by applying a greater force. The structure and materials of the appliance can be selected according to these requirements as needed; for example, by selecting a palatal expander capable of applying a large force to split the palatal suture and / or cause a rapid expansion of the palate. Subsequent appliance stages can be designed to apply different amounts of force, such as first applying a large force to disrupt the suture and then applying a smaller force to keep the suture separated or gradually expand the palate and / or dental arch.

[0147] The determination of the force system can also include modeling the patient's facial structure, such as the skeletal structure of the jaw and palate. For example, scan data of the palate and dental arch (such as X-ray data or 3D optical scan data) can be used to determine the parameters of the patient's oral skeletal and muscular systems in order to determine the forces sufficient to provide the desired expansion of the palate and / or dental arch. In some embodiments, the thickness and / or density of the palatal suture can be input by a measurement or treatment professional. In other embodiments, the treatment professional can select an appropriate treatment based on the patient's physiological characteristics. For example, the characteristics of the palate can also be estimated based on factors such as the patient's age. For example, younger adolescent patients will require less force to expand the suture than older patients because the suture has not yet fully formed.

[0148] In block 1006, a design for an orthodontic appliance configured to generate a force system is determined. The design can include appliance geometry, material composition, and / or material properties and can be determined in various ways, such as using a treatment or force application simulation environment. The simulation environment can include, for example, a computer modeling system, a biomechanical system or device, etc. Optionally, a digital model of the appliance and / or teeth can be generated, such as a finite element model. Computer program application software available from various vendors can be used to create the finite element model. To create a solid geometry model, a computer-aided engineering (CAE) or computer-aided design (CAD) program can be used, such as the software product available from Autodesk, Inc. of San Rafael, California. To create and analyze the finite element model, program products from multiple vendors can be used, including the finite element analysis package from ANSYS, Inc. of Canonsburg, Pennsylvania, and the SIMULIA (Abaqus) software product from Dassault Systèmes of Waltham, Massachusetts.

[0149] Optionally, one or more designs can be selected for testing or force modeling. As described above, the desired tooth movement and the force system required or desired to effect the desired tooth movement can be identified. Using the simulation environment, candidate designs can be analyzed or modeled to determine the actual force system generated by using the candidate appliance. Optionally, one or more modifications can be made to the candidate appliance, and force modeling can be further analyzed as described, e.g., to iteratively determine the appliance design that generates the desired force system.

[0150] In block 1008, instructions for manufacturing an orthodontic appliance incorporating the design are generated. The instructions can be configured to control a manufacturing system or device to produce an orthodontic appliance having the specified design. In some embodiments, the instructions are configured to manufacture the orthodontic appliance using direct manufacturing (e.g., stereolithography, selective laser sintering, fused deposition modeling, 3D printing, continuous direct manufacturing, multi-material direct manufacturing, etc.) according to the various methods presented herein. In alternative embodiments, the instructions can be configured to manufacture the appliance indirectly, e.g., by thermoforming.

[0151] Although the above steps illustrate a method 1000 of designing an orthodontic appliance according to some embodiments, those of ordinary skill in the art will recognize some variations based on the teachings described herein. Some steps may include sub-steps. Some steps may be repeated as often as needed. One or more steps of method 1000 may be performed with any suitable manufacturing system or apparatus, such as the embodiments described herein. Some steps may be optional; for example, the process of block 1004 may be omitted such that the orthodontic appliance is designed based on desired tooth movement and / or a determined tooth movement path rather than based on a force system. Additionally, the order of the steps may be changed as needed.

[0152] Figure 11 A method 1100 for digitally planning orthodontic treatment and / or the design or manufacture of an appliance according to an embodiment is shown. Method 1100 may be applied to any treatment procedure described herein and may be executed by any suitable data processing system.

[0153] In block 1102, a digital representation of a patient's teeth is received. The digital representation may include surface topography data of the patient's oral cavity (including teeth, gingival tissue, etc.). The surface topography data may be generated by directly scanning the oral cavity, a physical model (positive or negative mold) of the oral cavity, or an impression of the oral cavity using a suitable scanning device (e.g., a hand-held scanner, a desktop scanner, etc.).

[0154] In block 1104, one or more treatment phases are generated based on the digital representation of the teeth. The treatment phases may be progressive repositioning phases of an orthodontic treatment process that are designed to move one or more of the patient's teeth from an initial tooth alignment to a target alignment. For example, treatment phases may be generated by determining the initial tooth alignment indicated by the digital representation, determining the target tooth alignment, and determining the movement paths of one or more of the teeth in the initial alignment required to achieve the target tooth alignment. The movement paths may be optimized based on minimizing the total distance of movement, preventing collisions between teeth, avoiding more difficult-to-achieve tooth movements, or any other suitable criteria.

[0155] In block 1106, at least one orthodontic appliance is manufactured based on the generated treatment phases. For example, a set of appliances may be manufactured, each appliance being shaped according to the tooth alignment specified by one of the treatment phases such that the appliances may be sequentially worn by the patient to progressively reposition the teeth from the initial alignment to the target alignment. The set of appliances may include one or more of the orthodontic appliances described herein. The manufacture of the appliances may involve creating a digital model of the appliances for use as an input to a computer-controlled manufacturing system. As needed, direct manufacturing methods, indirect manufacturing methods, or a combination thereof may be used to form the appliances.

[0156] In some cases, staging of the various alignments or treatment phases may not be necessary for the design and / or manufacture of the appliance. As Figure 11 shown by the dashed lines in Figure 11 , the design and / or manufacture of the orthodontic appliance and possibly a particular orthodontic treatment can include using a representation of the patient's teeth (e.g., including receiving a digital representation of the patient's teeth (block 1102)), and then designing and / or manufacturing the orthodontic appliance based on the representation of the patient's teeth in the alignment represented by the received representation.

[0157] As described herein, the techniques described herein can be used to directly manufacture dental appliances, such as aligners and / or a series of aligners having tooth receiving cavities, which are configured to move a person's teeth from an initial alignment towards a target alignment according to a treatment plan. The aligners can include mandibular repositioning elements, such as those described in: U.S. Patent No. 10,912,629, entitled "Dental Appliances with Repositioning Jaw Elements", filed November 30, 2015; U.S. Patent No. 10,537,406, entitled "Dental Appliances with Repositioning Jaw Elements", filed September 19, 2014; and U.S. Patent No. 9,844,424, entitled "Dental Appliances with Repositioning Jaw Elements", filed February 21, 2014; the entire disclosures of these U.S. patents are incorporated herein by reference in their entirety.

[0158] The techniques used herein can also be used to fabricate attachment placement devices, e.g., appliances for positioning prefabricated attachments on a person's teeth in accordance with one or more aspects of a treatment plan. Examples of attachment placement devices (also referred to as "attachment placement templates" or "attachment fabrication templates") can be found at least in the following: U.S. Application No. 17 / 249,218, filed Feb. 24, 2021, entitled "Flexible 3D Printed Orthodontic Device"; U.S. Application No. 16 / 366,686, filed Mar. 27, 2019, entitled "Dental Attachment Placement Structure"; U.S. Application No. 15 / 674,662, filed Aug. 11, 2017, entitled "Devices and Systems for Creation of Attachments"; U.S. Patent No. 11,103,330, filed Jun. 14, 2017, entitled "Dental Attachment Placement Structure"; U.S. Application No. 14 / 963,527, filed Dec. 9, 2015, entitled "Dental Attachment Placement Structure"; U.S. Application No. 14 / 939,246, filed Nov. 12, 2015, entitled "Dental Attachment Placement Structure"; U.S. Application No. 14 / 939,252, filed Nov. 12, 2015, entitled "Dental Attachment Formation Structures"; and U.S. Patent No. 9,700,385, filed Aug. 22, 2014, entitled "Attachment Structure"; the entire disclosures of which are incorporated herein by reference in their entireties.

[0159] The techniques described herein can be used to fabricate a progressive palatal expander and / or a series of progressive palatal expanders for expanding a person's palate from an initial position toward a target position in accordance with one or more aspects of a treatment plan. Examples of progressive palatal expanders can be found at least in: U.S. Application No. 16 / 380,801, filed Apr. 10, 2019, entitled "Releasable Palatal Expanders"; U.S. Application No. 16 / 022,552, filed Jun. 28, 2018, entitled "Devices, Systems, and Methods for Dental Arch Expansion"; U.S. Patent No. 11,045,283, filed Jun. 8, 2018, entitled "Palatal Expander with Skeletal Anchorage Devices"; U.S. Application No. 15 / 831,159, filed Dec. 4, 2017, entitled "Palatal Expanders and Methods of Expanding a Palate"; U.S. Patent No. 10,993,783, filed Dec. 4, 2017, entitled "Methods and Apparatuses for Customizing a Rapid Palatal Expander"; and U.S. Patent No. 7,192,273, filed Aug. 7, 2003, entitled "System and Method for Palatal Expansion"; the entire contents of which are incorporated herein by reference in their entirety. (U.S. Application No. 16 / 022,552, filed Jun. 28, 2018, entitled "Devices, Systems, and Methods for Dental Arch Expansion"; U.S. Patent No. 11,045,283, filed Jun. 8, 2018, entitled "Palatal Expander with Skeletal Anchorage Devices"; U.S. Application No. 15 / 831,159, filed Dec. 4, 2017, entitled "Palatal Expanders and Methods of Expanding a Palate"; U.S. Patent No. 10,993,783, filed Dec. 4, 2017, entitled "Methods and Apparatuses for Customizing a Rapid Palatal Expander"; and U.S. Patent No. 7,192,273, filed Aug. 7, 2003, entitled "System and Method for Palatal Expansion"; the entire contents of which are incorporated herein by reference in their entirety.) Examples

[0160] Examples are included to further describe some aspects of the present techniques, and these examples are not to be used to limit the scope of the present techniques.

[0161] Example 1. A system, comprising: A controller configured to provide one or more control signals; A heater coupled to the controller, wherein the heater includes one or more heating elements arranged to heat a blasting medium in response to the one or more control signals; A chamber, coupled to the controller, wherein the chamber includes an agitating drum configured to receive a plurality of additively manufactured objects and to agitate the plurality of additively manufactured objects in response to the one or more control signals; and A filler, coupled to the controller, wherein the filler includes a nozzle operable to direct a plurality of thermally conductive particles in the abrasive medium toward the plurality of additively manufactured objects within the agitating drum in response to the one or more control signals.

[0162] Example 2. The system according to Example 1, further comprising a medium source coupled to the heater, wherein the medium source is arranged to contain the abrasive medium.

[0163] Example 3. The system according to Example 1 or 2, wherein the agitating drum includes a rotating drum, a translating drum, or a combination thereof.

[0164] Example 4. The system according to any one of Examples 1 to 3, wherein the abrasive medium includes metal particles, ceramic particles, or a combination thereof.

[0165] Example 5. The system according to any one of Examples 1 to 4, wherein the agitating drum includes an interior portion configured to allow removal of excess thermally conductive particles from the plurality of thermally conductive particles.

[0166] Example 6. The system according to Example 5, wherein the interior portion includes perforations to allow removal of the excess thermally conductive particles.

[0167] Example 7. The system according to any one of Examples 1 to 6, wherein the agitating drum includes an exterior portion to catch excess thermally conductive particles from the plurality of thermally conductive particles.

[0168] Example 8. The system according to Example 7, wherein the exterior portion does not have perforations.

[0169] Example 9. The system according to any one of Examples 1 to 8, further comprising a sensor coupled to the controller, wherein the sensor is operable to sense whether the agitating drum has an excessive mechanical load.

[0170] Example 10. The system according to Example 9, wherein the excessive mechanical load includes excessive torque, excessive force, or a combination thereof.

[0171] Example 11. The system according to Example 9 or 10, wherein in response to determining that the agitating drum has an excessive mechanical load, the controller is operable to shut down the agitating drum, decelerate the agitating drum, or a combination thereof.

[0172] Example 12. The system according to any one of Examples 9 to 11, wherein the excessive mechanical load is caused by at least some of the heat-conducting particles not leaving the perforations in the inner part of the stirrable drum.

[0173] Example 13. The system according to any one of Examples 1 to 12, wherein the plurality of additively manufactured objects includes an additively manufactured palatal expander for expanding a human palate from a first arrangement towards a second arrangement.

[0174] Example 14. The system according to any one of Examples 1 to 13, wherein the plurality of additively manufactured objects includes a series of progressive palatal expanders for expanding a human palate from a first arrangement towards a second arrangement.

[0175] Example 15. The system according to any one of Examples 1 to 14, wherein the plurality of additively manufactured objects includes a series of progressive palatal expanders for expanding a human palate from an initial arrangement towards a target arrangement.

[0176] Example 16. The system according to any one of Examples 1 to 15, wherein the plurality of additively manufactured objects includes a batch of progressive palatal expanders for expanding the palate of one or more humans.

[0177] Example 17. The system according to any one of Examples 1 to 16, wherein the plurality of additively manufactured objects includes a batch of progressive palatal expanders for expanding the palates of multiple humans.

[0178] Example 18. The system according to any one of Examples 1 to 16, wherein: the plurality of additively manufactured objects includes a series of progressive palatal expanders for expanding a human palate from an initial arrangement towards a target arrangement according to a treatment plan; and the series of progressive palatal expanders is associated with a single individual.

[0179] Example 19. The system according to any one of Examples 1 to 18, wherein the plurality of additively manufactured objects is made of a thermoplastic material.

[0180] Example 20. A system comprising: a controller configured to provide one or more control signals; a heater coupled to the controller, wherein the heater includes one or more heating elements arranged to heat a blasting medium in response to the one or more control signals; A chamber, coupled to the controller, wherein the chamber includes an agitating drum configured to receive a plurality of additively manufactured objects and to agitate the plurality of additively manufactured objects in response to the one or more control signals; and A filler, coupled to the controller, wherein the filler includes means for directing a plurality of thermally conductive particles in the abrasive medium toward the plurality of additively manufactured objects within the agitating drum in response to the one or more control signals.

[0181] Example 21. A method, comprising: Receiving a dental appliance manufactured from a thermoplastic material using an additive manufacturing process; Surface-modifying the dental appliance via mechanical deformation by applying an abrasive medium to a surface of the object, wherein the abrasive medium includes a plurality of thermally conductive particles heated to an elevated temperature; and Collecting the abrasive medium for reuse.

[0182] Example 22. The method according to Example 21, wherein surface-modifying the dental appliance includes reducing the roughness of the surface of the dental appliance, reducing the porosity of the surface of the dental appliance, or a combination thereof.

[0183] Example 23. The method according to Example 21 or 22, wherein the mechanical deformation includes plastic deformation.

[0184] Example 24. The method according to any one of Examples 21 to 23, wherein the thermoplastic material has a glass transition temperature and the elevated temperature is greater than or equal to the glass transition temperature.

[0185] Example 25. The method according to any one of Examples 21 to 24, wherein the elevated temperature is in the range of 50°C to 200°C.

[0186] Example 26. The method according to any one of Examples 21 to 25, wherein the plurality of thermally conductive particles are made of metal, ceramic, or a combination thereof.

[0187] Example 27. The method according to any one of Examples 21 to 26, wherein the plurality of thermally conductive particles have an average diameter in the range of 50 μm to 2 mm.

[0188] Example 28. The method according to any one of Examples 21 to 27, wherein the elevated temperature is a first elevated temperature, and the method further includes adjusting an ambient temperature to a second elevated temperature while applying the abrasive medium to the surface of the dental appliance.

[0189] Example 29. The method according to Example 28, wherein the second elevated temperature is in the range of 30 °C to 100 °C.

[0190] Example 30. The method according to any one of Examples 21 to 29, wherein the additive manufacturing process comprises selective laser sintering.

[0191] Example 31. The method according to any one of Examples 21 to 30, wherein the dental appliance is a palatal expander.

[0192] Example 32. A system for treating an object produced by additive manufacturing, the system comprising: a chamber configured to receive a dental appliance made of a thermoplastic material using an additive manufacturing process; a blaster configured to direct a blasting medium towards the object within the chamber to cause mechanical deformation of the surface of the object, wherein the blasting medium comprises a plurality of thermally conductive particles; a first heating element configured to heat the blasting medium to a first elevated temperature; and a second heating element configured to heat the chamber to a second elevated temperature.

[0193] Example 33. The system according to Example 32, wherein the mechanical deformation causes a reduction in the surface roughness of the dental appliance, a reduction in the surface porosity of the dental appliance, or a combination thereof.

[0194] Example 34. The system according to Example 32 or 33, wherein the thermoplastic material has a glass transition temperature, and the first elevated temperature is greater than or equal to the glass transition temperature.

[0195] Example 35. The system according to any one of Examples 32 to 34, wherein the first elevated temperature is in the range of 50 °C to 200 °C.

[0196] Example 36. The system according to any one of Examples 32 to 35, wherein the plurality of thermally conductive particles are made of metal, ceramic, or a combination thereof.

[0197] Example 37. The system according to any one of Examples 32 to 36, wherein the plurality of thermally conductive particles have an average diameter in the range of 50 μm to 2 mm.

[0198] Example 38. The system according to any one of Examples 32 to 37, wherein the second elevated temperature is in the range of 30 °C to 100 °C.

[0199] Example 39. The system according to any one of Examples 32 to 38, further comprising: A drum, configured to receive an object, and An actuator, configured to rotate the drum while the filler directs the abrasive medium towards the object.

[0200] Example 40. The system according to any one of Examples 32 to 39, further comprising a container configured to collect the abrasive medium for reuse.

[0201] Example 41. A method, comprising: Receiving an object manufactured using an additive manufacturing process; Modifying the surface of the object via mechanical deformation by applying an abrasive medium to the surface of the object, wherein the abrasive medium is heated to an elevated temperature; and Collecting the abrasive medium for reuse.

[0202] Example 42. The method according to Example 41, wherein the additive manufacturing process comprises selective laser sintering.

[0203] Example 43. The method according to Example 41 or 42, wherein the object is made of a biocompatible material.

[0204] Example 44. The method according to any one of Examples 41 to 43, wherein modifying the surface of the object comprises reducing the roughness of the surface of the object.

[0205] Example 45. The method according to any one of Examples 41 to 44, wherein modifying the surface of the object comprises reducing the porosity of the surface of the object.

[0206] Example 46. The method according to any one of Examples 41 to 45, wherein the mechanical deformation comprises plastic deformation.

[0207] Example 47. The method according to any one of Examples 41 to 46, wherein the object is made of a thermoplastic material.

[0208] Example 48. The method according to Example 47, wherein the thermoplastic material comprises a glass transition temperature, and the elevated temperature is greater than or equal to the glass transition temperature.

[0209] Example 49. The method according to Example 47 or 48, further comprising selecting the elevated temperature based on the thermoplastic material.

[0210] Example 50. The method according to any one of Examples 41 to 49, wherein the elevated temperature is in the range of 50°C to 200°C.

[0211] Example 51. The method according to any one of Examples 41 to 50, wherein the abrasive medium comprises a thermally conductive material.

[0212] Example 52. The method according to Example 51, wherein the thermally conductive material comprises a metal, a ceramic, or a combination thereof.

[0213] Example 53. The method according to Example 51 or 52, wherein the thermally conductive material comprises a metal, and the method further comprises heating the abrasive medium to the elevated temperature by induction.

[0214] Example 54. The method according to any one of Examples 41 to 53, wherein the abrasive medium comprises a plurality of particles.

[0215] Example 55. The method according to Example 54, wherein the plurality of particles have an average diameter in the range of 50 μm to 2 mm.

[0216] Example 56. The method according to any one of Examples 41 to 55, wherein the elevated temperature is a first elevated temperature, and the method further comprises adjusting an ambient temperature to a second elevated temperature while applying the abrasive medium to a surface of the object.

[0217] Example 57. The method according to Example 56, wherein the second elevated temperature is lower than the first elevated temperature.

[0218] Example 58. The method according to Example 56 or 57, wherein the second elevated temperature is in the range of 30 °C to 100 °C.

[0219] Example 59. The method according to any one of Examples 41 to 58, further comprising rotating the object while applying the abrasive medium.

[0220] Example 60. The method according to any one of Examples 41 to 59, wherein the object is an orthodontic appliance.

[0221] Example 61. The method according to Example 60, wherein the orthodontic appliance is a palatal expander.

[0222] Example 62. A system for treating an object manufactured by additive manufacturing, the system comprising: a chamber configured to receive an object manufactured using an additive manufacturing process; a filler configured to direct an abrasive medium toward the object within the chamber to cause mechanical deformation of a surface of the object, wherein the abrasive medium is heated to a first elevated temperature; a first heating element configured to heat the abrasive medium to the first elevated temperature; and A second heating element configured to heat the chamber to a second elevated temperature.

[0223] Example 63. The system according to Example 62, wherein the mechanical deformation is configured to reduce the roughness of the surface of the object.

[0224] Example 64. The system according to Example 62 or 63, wherein the mechanical deformation is configured to reduce the porosity of the surface of the object.

[0225] Example 65. The system according to any one of Examples 62 to 64, wherein the mechanical deformation includes plastic deformation.

[0226] Example 66. The system according to any one of Examples 62 to 65, wherein the object is made of a thermoplastic material.

[0227] Example 67. The system according to Example 66, wherein the thermoplastic material includes a glass transition temperature, and the first elevated temperature is greater than or equal to the glass transition temperature.

[0228] Example 68. The system according to any one of Examples 62 to 67, wherein the first elevated temperature is in the range of 50 °C to 200 °C.

[0229] Example 69. The system according to any one of Examples 62 to 68, wherein the sandblasting medium includes a thermally conductive material.

[0230] Example 70. The system according to Example 69, wherein the thermally conductive material includes a metal, a ceramic, or a combination thereof.

[0231] Example 71. The system according to Example 69 or 70, wherein the thermally conductive material includes a metal, and the first heating element is an induction heater.

[0232] Example 72. The system according to any one of Examples 62 to 71, wherein the sandblasting medium includes a plurality of particles.

[0233] Example 73. The system according to Example 72, wherein the plurality of particles have an average diameter in the range of 50 μm to 2 mm.

[0234] Example 74. The system according to any one of Examples 62 to 73, wherein the first heating element includes one or more of the following: a heated fluid source, an induction heater, a thermoelectric heater, or a heat pump.

[0235] Example 75. The system according to any one of Examples 62 to 74, wherein the second heating element comprises one or more of the following: a heated fluid source, a thermoelectric heater, or a heat pump.

[0236] Example 76. The system according to any one of Examples 62 to 75, wherein the second elevated temperature is lower than the first elevated temperature.

[0237] Example 77. The system according to any one of Examples 62 to 76, wherein the second elevated temperature is in the range of 30 °C to 100 °C.

[0238] Example 78. The system according to any one of Examples 62 to 77, further comprising: a drum configured to receive the object, and an actuator configured to rotate the drum while the filler directs the abrasive medium towards the object.

[0239] Example 79. The system according to any one of Examples 62 to 78, further comprising a container configured to collect the abrasive medium for reuse.

[0240] Example 80. The system according to any one of Examples 62 to 79, further comprising an additive manufacturing device configured to manufacture the object using the additive manufacturing process.

[0241] Example 81. The system according to Example 80, wherein the additive manufacturing process comprises selective laser sintering.

[0242] Example 82. The system according to any one of Examples 62 to 81, wherein the object is an orthodontic appliance.

[0243] Example 83. A method, comprising: receiving a dental appliance manufactured from a thermoplastic material using an additive manufacturing process; obtaining height data of the surface of the dental appliance via at least one sensor; and modifying the surface of the dental appliance by applying heat to the surface of the dental appliance using at least one heating element, wherein the at least one heating element is adjusted based on the height data.

[0244] Example 84. The method according to Example 83, wherein modifying the surface of the dental appliance comprises reducing the roughness of the surface of the dental appliance, reducing the porosity of the surface of the dental appliance, or a combination thereof.

[0245] Example 85. The method according to Example 83 or 84, wherein modifying the surface of the dental appliance comprises melting the surface of the dental appliance.

[0246] Example 86. The method according to Example 85, wherein the surface of the dental appliance is melted to a depth of no more than 50 μm.

[0247] Example 87. The method according to any one of Examples 83 to 86, wherein adjusting the at least one heating element includes adjusting one or more of the following: the position of the at least one heating element, the orientation of the at least one heating element, or the intensity of the at least one heating element.

[0248] Example 88. The method according to any one of Examples 83 to 87, wherein adjusting the at least one heating element includes adjusting the vertical position of the at least one heating element relative to the dental appliance based on the height data.

[0249] Example 89. The method according to any one of Examples 83 to 88, wherein the at least one heating element includes a plurality of heating elements positioned at different locations relative to the dental appliance.

[0250] Example 90. The method according to any one of Examples 83 to 89, wherein the at least one heating element includes one or more of the following: a flame generator, a plasma generator, or a corona generator.

[0251] Example 91. The method according to any one of Examples 83 to 90, wherein the at least one sensor includes an imaging device or a distance sensor.

[0252] Example 92. The method according to any one of Examples 83 to 91, further comprising: identifying a first appliance portion having a first height, identifying a second appliance portion having a second height different from the first height, applying heat to the first appliance portion using a first set of heating parameters, and applying heat to the second appliance portion using a second set of heating parameters.

[0253] Example 93. The method according to any one of Examples 83 to 92, wherein the dental appliance is a palatal expander.

[0254] Example 94. A system for processing an object made by additive manufacturing, the system comprising: a sensor configured to generate height data; at least one heating element; at least one processor; and A memory, operably coupled to the at least one processor and storing instructions that, when executed by the processor, cause the system to perform operations, the operations including: Receiving height data of a surface of a dental appliance manufactured using an additive manufacturing process from the sensor, and Applying heat to the surface of the dental appliance via the at least one heating element and based on the height data.

[0255] Example 95. The system according to example 94, wherein the heat is configured to reduce the roughness of the surface of the dental appliance, reduce the porosity of the surface of the dental appliance, or a combination thereof.

[0256] Example 96. The system according to example 94 or 95, wherein the heat is configured to melt the surface of the dental appliance.

[0257] Example 97. The method according to example 96, wherein the surface of the dental appliance is melted to a depth of no more than 50 μm.

[0258] Example 98. The method according to any one of examples 94 to 97, wherein the at least one heating element includes one or more of the following: a flame generator, a plasma generator, or a corona generator.

[0259] Example 99. The system according to any one of examples 94 to 98, wherein the operation further includes adjusting the at least one heating element based on the height data.

[0260] Example 100. The system according to example 99, wherein adjusting the at least one heating element includes adjusting one or more of the following: the position of the at least one heating element, the orientation of the at least one heating element, or the intensity of the at least one heating element.

[0261] Example 101. The system according to any one of examples 94 to 100, wherein the at least one heating element is movable.

[0262] Example 102. The method according to any one of examples 94 to 101, wherein the at least one heating element includes a plurality of heating elements positioned at different locations relative to the dental appliance.

[0263] Example 103. The system according to any one of examples 94 to 102, wherein the sensor includes an imaging device or a distance sensor.

[0264] Example 104. A method, including: Receiving an object manufactured using an additive manufacturing process; Obtain the topography data of the surface of the object via at least one sensor; Modify the surface of the object by applying heat to the surface of the object based on the topography data.

[0265] Example 105. The method according to Example 104, wherein the additive manufacturing process includes selective laser sintering.

[0266] Example 106. The method according to Example 104 or 105, wherein the object is made of a thermoplastic material.

[0267] Example 107. The method according to any one of Examples 104 to 106, wherein the object is made of a biocompatible material.

[0268] Example 108. The method according to any one of Examples 104 to 107, wherein modifying the surface of the object includes melting the surface of the object.

[0269] Example 109. The method according to Example 108, wherein the surface of the object is melted to a depth of no more than 50 μm.

[0270] Example 110. The method according to any one of Examples 104 to 109, wherein modifying the surface of the object includes reducing the roughness of the surface of the object.

[0271] Example 111. The method according to any one of Examples 104 to 110, wherein modifying the surface of the object includes reducing the porosity of the surface of the object.

[0272] Example 112. The method according to any one of Examples 104 to 111, wherein the heat is applied to the surface of the object via at least one heating element.

[0273] Example 113. The method according to Example 112, further comprising adjusting the at least one heating element based on the topography data.

[0274] Example 114. The method according to Example 113, wherein adjusting the at least one heating element includes adjusting one or more of the following: the position of the at least one heating element, the orientation of the at least one heating element, or the intensity of the at least one heating element.

[0275] Example 115. The method according to Example 113 or 114, wherein the topography data includes height data, and adjusting the at least one heating element includes adjusting the vertical position of the at least one heating element relative to the object based on the height data.

[0276] Example 116. The method according to any one of Examples 112 to 115, wherein the at least one heating element comprises a plurality of heating elements positioned at different locations relative to the object.

[0277] Example 117. The method according to Example 116, further comprising adjusting the intensity of each of the plurality of heating elements based on the topography data.

[0278] Example 118. The method according to any one of Examples 104 to 117, wherein the at least one sensor comprises an imaging device or a distance sensor.

[0279] Example 119. The method according to any one of Examples 104 to 118, further comprising: identifying a first object portion having a first surface topography, identifying a second object portion having a second surface topography different from the first surface topography, applying heat to the first object portion using a first set of heating parameters, and applying heat to the second object portion using a second set of heating parameters.

[0280] Example 120. The method according to any one of Examples 104 to 119, further comprising receiving additional data indicative of at least one characteristic of the object, wherein the heat is applied based on the additional data.

[0281] Example 121. The method according to Example 100, wherein the additional data indicates one or more of the following characteristics: the type of the object, the geometry of the object, the type of material used to form the object, the characteristics of the material used to form the object, the location of the material used to form the object, or the initial surface characteristics of the object.

[0282] Example 122. The method according to Example 120 or 121, further comprising: receiving an identifier of the object, and using the identifier to obtain the additional data from a database.

[0283] Example 123. The method according to any one of Examples 104 to 122, wherein the object is an orthodontic appliance.

[0284] Example 124. The method according to Example 123, wherein the orthodontic appliance is a palatal expander.

[0285] Example 125. A system for processing an object produced by additive manufacturing, the system comprising: a sensor configured to generate topography data; at least one heating element; at least one processor; and a memory operably coupled to the at least one processor and storing instructions that, when executed by the processor, cause the system to perform operations, the operations including: receiving topography data from the sensor, wherein the topography data characterizes a surface of an object manufactured using an additive manufacturing process, and applying heat to the surface of the object via the at least one heating element and based on the topography data.

[0286] Example 126. The system according to Example 125, wherein the heat is configured to melt the surface of the object.

[0287] Example 127. The system according to Example 126, wherein the surface of the object is melted to a depth of no more than 50 μm.

[0288] Example 128. The system according to any one of Examples 125 to 127, wherein the heat is configured to reduce the roughness of the surface of the object.

[0289] Example 129. The system according to any one of Examples 125 to 128, wherein the heat is configured to reduce the porosity of the surface of the object.

[0290] Example 130. The system according to any one of Examples 125 to 129, wherein the at least one heating element includes one or more of the following: a flame generator, a plasma generator, or a corona generator.

[0291] Example 131. The system according to any one of Examples 125 to 130, wherein the operation further includes adjusting the at least one heating element based on the topography data.

[0292] Example 132. The system according to Example 131, wherein adjusting the at least one heating element includes adjusting one or more of the following: the position of the at least one heating element, the orientation of the at least one heating element, or the intensity of the at least one heating element.

[0293] Example 133. The system according to any one of Examples 125 to 132, wherein the at least one heating element is movable.

[0294] Example 134. The system according to any one of Examples 125 to 133, wherein the at least one heating element includes a plurality of heating elements positioned at different locations relative to the object.

[0295] Example 135. The system according to any one of Examples 125 to 134, wherein the at least one sensor includes an imaging device.

[0296] Example 136. The system according to any one of Examples 125 to 135, wherein the at least one sensor includes a distance sensor.

[0297] Example 137. The system according to any one of Examples 125 to 136, wherein the operation further comprises: identifying a first object portion having a first surface topography, identifying a second object portion having a second surface topography different from the first surface topography, applying heat to the first object portion using a first set of heating parameters, and applying heat to the second object portion using a second set of heating parameters.

[0298] Example 138. The system according to any one of Examples 125 to 137, wherein the operation further comprises receiving additional data indicative of at least one characteristic of the object, and applying the heat based on the additional data.

[0299] Example 139. The system according to Example 138, wherein the additional data indicates one or more of the following characteristics: the type of the object, the geometry of the object, the type of the material used to form the object, the characteristics of the material used to form the object, the location of the material used to form the object, or the initial surface characteristics of the object.

[0300] Example 140. The system according to Example 139, wherein the operation further comprises: receiving an identifier of the object, and using the identifier to obtain the additional data from a database.

[0301] Example 141. The system according to any one of Examples 125 to 140, further comprising an additive manufacturing device configured to manufacture the object using the additive manufacturing process.

[0302] Example 142. The system according to Example 141, wherein the additive manufacturing process includes selective laser sintering.

[0303] Example 143. The system according to any one of Examples 125 to 142, wherein the object is an orthodontic appliance. Conclusions

[0304] Although many embodiments have been described above with respect to systems, devices, and methods for manufacturing orthodontic appliances, the technology can be applied to other applications and / or other methods, such as other types of products where an improved surface finish is desired. Additionally, other embodiments beyond those described herein are also within the scope of the technology. Further, several other embodiments of the technology can have different configurations, components, or procedures than those described herein. Accordingly, one of ordinary skill in the art will understand that the technology can have other embodiments with additional elements, or that the technology can have other embodiments without several of the features referenced above Figures 1 to 11 shown and described.

[0305] The various processes described herein can be implemented, in part or in whole, using program code that includes instructions executable by one or more processors of a computing system for implementing specific logical functions or steps in the processes. The program code can be stored on any type of computer-readable medium, such as a storage device including a disk or hard drive. A computer-readable medium containing code or portions of code can include any suitable medium known in the art, such as a non-transitory computer-readable storage medium. A computer-readable medium can include volatile and non-volatile media, removable and non-removable media implemented in any method or technology for storing and / or transmitting information, including but not limited to random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies; compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage devices; magnetic cassettes, magnetic tape, magnetic disk storage devices or other magnetic storage devices; solid state drives (SSD) or other solid state storage devices; or any other medium that can be used to store the desired information and that can be accessed by a system device.

[0306] The description of embodiments of the technology is not intended to be exhaustive or to limit the technology to the precise forms disclosed above. Where context permits, singular or plural terms may also respectively include plural or singular terms. Although specific embodiments and examples of the technology have been described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology, as will be recognized by those of ordinary skill in the relevant art. For example, while steps are presented in a given order, alternative embodiments can execute the steps in a different order. Various embodiments described herein can also be combined to provide additional embodiments.

[0307] As used herein, terms such as "substantially," "essentially," "about," and the like are used as approximate terms and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values recognized by one of ordinary skill in the art.

[0308] In addition, unless the word "or" is explicitly limited to mean only a single item, excluding other items in a list of two or more items, the use of "or" in such a list shall be construed to include (a) any single item in the list, (b) all items in the list, or (c) any combination of items in the list. As used herein, the phrase "and / or" in "A and / or B" means A alone, B alone, and both A and B. Additionally, the term "comprising" is used throughout to mean including at least the stated (one or more) features, such that any greater number of the same features and / or additional types of other features are not excluded.

[0309] If any material incorporated by reference herein conflicts with the present disclosure, the present disclosure shall control.

[0310] It should also be understood that specific embodiments have been described herein for purposes of illustration, but various modifications may be made without departing from the technology. Additionally, while the advantages associated with certain embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments must exhibit such advantages to fall within the scope of the technology. Accordingly, the present disclosure and the associated technology may cover other embodiments not expressly shown or described herein.

Claims

1. A system, comprising: A controller configured to provide one or more control signals; A heater coupled to the controller, wherein the heater includes one or more heating elements configured to heat a blasting medium in response to the one or more control signals; A chamber coupled to the controller, wherein the chamber includes a stirrable drum configured to receive a plurality of additive manufactured objects and to stir the plurality of additive manufactured objects in response to the one or more control signals; and A filler coupled to the controller, wherein the filler includes a nozzle operable to direct a plurality of thermally conductive particles in the blasting medium towards the plurality of additive manufactured objects within the stirrable drum in response to the one or more control signals.

2. The system according to claim 1, further comprising a medium source coupled to the heater, wherein, The medium source is arranged to contain the blasting medium.

3. The system according to claim 1 or 2, wherein, The stirrable drum includes a rotating drum, a translating drum, or a combination thereof.

4. The system according to any one of claims 1 to 3, wherein, The blasting medium includes metal particles, ceramic particles, or a combination thereof.

5. The system according to any one of claims 1 to 4, wherein, The stirrable drum includes an interior portion configured to allow removal of excess thermally conductive particles from the plurality of thermally conductive particles.

6. The system according to claim 5, wherein, The interior portion includes perforations to allow removal of the excess thermally conductive particles.

7. The system according to any one of claims 1 to 6, wherein, The stirrable drum includes an exterior portion to catch the excess thermally conductive particles from the plurality of thermally conductive particles.

8. The system according to claim 7, wherein The exterior portion does not have perforations.

9. The system according to any one of claims 1 to 8 further includes a sensor coupled to the controller, wherein, The sensor is operable to sense whether the stirrable drum has an excessive mechanical load.

10. The system according to claim 9, wherein, The excessive mechanical load includes excessive torque, excessive force, or a combination thereof.

11. The system according to claim 9 or 10, wherein, In response to determining that the stirrable drum has an excessive mechanical load, the controller is operable to shut down the stirrable drum, slow down the stirrable drum, or perform a combination thereof.

12. The system according to any one of claims 9 to 11, wherein, The excessive mechanical load is due to at least some of the thermally conductive particles not leaving the perforations in the interior portion of the stirrable drum.

13. The system according to any one of claims 1 to 12, wherein, The plurality of additive manufactured objects includes an additive manufactured palatal expander for expanding a human palate from a first arrangement towards a second arrangement.

14. The system according to any one of claims 1 to 13, wherein, The plurality of additive manufactured objects includes a series of progressive palatal expanders for expanding a human palate from a first arrangement towards a second arrangement.

15. The system according to any one of claims 1 to 14, wherein, The plurality of additive manufactured objects includes a series of progressive palatal expanders for expanding a human palate from an initial arrangement towards a target arrangement.

16. The system according to any one of claims 1 to 15, wherein, The plurality of additive manufactured objects includes a batch of progressive palatal expanders for expanding the palate of one or more humans.

17. The system according to any one of claims 1 to 16, wherein the plurality of additive manufactured objects includes a batch of progressive palatal expanders for expanding the palates of multiple humans.

18. The system according to any one of claims 1 to 16, wherein: The plurality of additive manufactured objects includes a series of progressive palatal expanders for expanding a human palate from an initial arrangement towards a target arrangement according to a treatment plan; and The series of progressive palatal expanders is associated with a single individual.

19. The system according to any one of claims 1 to 18, wherein, The plurality of additive manufactured objects is made of a thermoplastic material.

20. A system, comprising: A controller configured to provide one or more control signals; A heater, coupled to the controller, wherein the heater includes one or more heating elements configured to heat the abrasive media in response to the one or more control signals; A chamber, coupled to the controller, wherein the chamber includes an agitating drum configured to receive a plurality of additive manufactured objects and to agitate the plurality of additive manufactured objects in response to the one or more control signals; and A filler, coupled to the controller, wherein the filler includes means for directing a plurality of thermally conductive particles in the abrasive media towards the plurality of additive manufactured objects within the agitating drum in response to the one or more control signals.

21. A method, comprising: Receiving a dental appliance manufactured from a thermoplastic material using an additive manufacturing process; Modifying a surface of the dental appliance via mechanical deformation by applying an abrasive media to the surface of the object, wherein the abrasive media includes a plurality of thermally conductive particles heated to an elevated temperature; And Collecting the abrasive media for reuse.

22. The method according to claim 21, wherein, Modifying the surface of the dental appliance includes reducing the roughness of the surface of the dental appliance, reducing the porosity of the surface of the dental appliance, or a combination thereof.

23. The method according to claim 21 or 22, wherein, The mechanical deformation includes plastic deformation.

24. The method according to any one of claims 21 to 23, wherein, The thermoplastic material has a glass transition temperature, and the elevated temperature is greater than or equal to the glass transition temperature.

25. The method according to any one of claims 21 to 24, wherein The elevated temperature is in the range of 50 °C to 200 °C.

26. The method according to any one of claims 21 to 25, wherein, The plurality of thermally conductive particles are made of metal, ceramic, or a combination thereof.

27. The method according to any one of claims 21 to 26, wherein The plurality of thermally conductive particles have an average diameter in the range of 50 μm to 2 mm.

28. The method according to any one of claims 21 to 27, wherein, The elevated temperature is a first elevated temperature, and the method further includes adjusting an ambient temperature to a second elevated temperature while applying the abrasive media to the surface of the dental appliance.

29. The method according to claim 28, wherein, The second elevated temperature is in the range of 30 °C to 100 °C.

30. The method according to any one of claims 21 to 29, wherein The additive manufacturing process includes selective laser sintering.

31. The method according to any one of claims 21 to 30, wherein, The dental appliance is a palatal expander.

32. A system for processing an additive manufactured object, the system comprising: A chamber configured to receive a dental appliance manufactured from a thermoplastic material using an additive manufacturing process; A filler configured to direct an abrasive media towards an object within the chamber to cause mechanical deformation of the surface of the object, wherein the abrasive media includes a plurality of thermally conductive particles; A first heating element configured to heat the abrasive media to a first elevated temperature; and A second heating element configured to heat the chamber to a second elevated temperature.

33. The system according to claim 32, wherein, The mechanical deformation causes a reduction in the roughness of the surface of the dental appliance, a reduction in the porosity of the surface of the dental appliance, or a combination thereof.

34. The system according to claim 32 or 33, wherein, The thermoplastic material has a glass transition temperature, and the first elevated temperature is greater than or equal to the glass transition temperature.

35. The system according to any one of claims 32 to 34, wherein, The first elevated temperature is in the range of 50 °C to 200 °C.

36. The system according to any one of claims 32 to 35, wherein, The plurality of thermally conductive particles are made of metal, ceramic, or a combination thereof.

37. The system according to any one of claims 32 to 36, wherein, The plurality of thermally conductive particles have an average diameter in the range of 50 μm to 2 mm.

38. The system according to any one of claims 32 to 37, wherein, The second elevated temperature is in the range of 30°C to 100°C.

39. The system according to any one of claims 32 to 38, further comprising: a drum configured to receive an object, and an actuator configured to rotate the drum while the filler directs the abrasive medium towards the object.

40. The system according to any one of claims 32 to 39, further comprising a container configured to collect the abrasive medium for reuse.

41. A method, comprising: receiving an object manufactured using an additive manufacturing process; modifying a surface of the object via mechanical deformation by applying an abrasive medium to the surface of the object, wherein the abrasive medium is heated to an elevated temperature; and collecting the abrasive medium for reuse.

42. The method according to claim 41, wherein, The additive manufacturing process includes selective laser sintering.

43. The method according to claim 41 or 42, wherein, The object is made of a biocompatible material.

44. The method according to any one of claims 41 to 43, wherein, Modifying the surface of the object includes reducing the roughness of the surface of the object.

45. The method according to any one of claims 41 to 44, wherein Modifying the surface of the object includes reducing the porosity of the surface of the object.

46. The method according to any one of claims 41 to 45, wherein The mechanical deformation includes plastic deformation.

47. The method according to any one of claims 41 to 46, wherein The object is made of a thermoplastic material.

48. The method according to claim 47, wherein, The thermoplastic material includes a glass transition temperature, and the elevated temperature is greater than or equal to the glass transition temperature.

49. The method according to claim 47 or 48, further comprising selecting the elevated temperature based on the thermoplastic material.

50. The method according to any one of claims 41 to 49, wherein, The elevated temperature is in the range of 50°C to 200°C.

51. The method according to any one of claims 41 to 50, wherein, The abrasive medium includes a heat-conductive material.

52. The method according to claim 51, wherein, The heat-conductive material includes a metal, a ceramic, or a combination thereof.

53. The method according to claim 51 or 52, wherein, The heat-conductive material includes a metal, and the method further comprises heating the abrasive medium to the elevated temperature via induction.

54. The method according to any one of claims 41 to 53, wherein, The abrasive medium includes a plurality of particles.

55. The method according to claim 54, wherein, The plurality of particles have an average diameter in the range of 50 μm to 2 mm.

56. The method according to any one of claims 41 to 55, wherein, The elevated temperature is a first elevated temperature, and the method further comprises adjusting an ambient temperature to a second elevated temperature while applying the abrasive medium to the surface of the object.

57. The method according to claim 56, wherein, The second elevated temperature is lower than the first elevated temperature.

58. The method according to claim 56 or 57, wherein, The second elevated temperature is in the range of 30°C to 100°C.

59. The method according to any one of claims 41 to 58, further comprising rotating the object while applying the abrasive medium.

60. The method according to any one of claims 41 to 59, wherein, The object is an orthodontic appliance.

61. The method according to claim 60, wherein, The orthodontic appliance is a palatal expander.

62. A system for processing an additively manufactured object, the system comprising: a chamber configured to receive an object manufactured using an additive manufacturing process; a filler configured to direct an abrasive medium towards the object within the chamber to cause mechanical deformation of the surface of the object, wherein the abrasive medium is heated to a first elevated temperature; a first heating element configured to heat the abrasive medium to the first elevated temperature; and a second heating element configured to heat the chamber to a second elevated temperature.

63. The system according to claim 62, wherein, The mechanical deformation is configured to reduce the roughness of the surface of the object.

64. The system according to claim 62 or 63, wherein, The mechanical deformation is configured to reduce the porosity of the surface of the object.

65. The system according to any one of claims 62 to 64, wherein, The mechanical deformation includes plastic deformation.

66. The system according to any one of claims 62 to 65, wherein, The object is made of a thermoplastic material.

67. The system according to claim 66, wherein, The thermoplastic material includes a glass transition temperature, and the first elevated temperature is greater than or equal to the glass transition temperature.

68. The system according to any one of claims 62 to 67, wherein The first elevated temperature is in the range of 50 °C to 200 °C.

69. The system according to any one of claims 62 to 68, wherein, The sandblasting medium includes a thermally conductive material.

70. The system according to claim 69, wherein, The thermally conductive material includes a metal, a ceramic, or a combination thereof.

71. The system according to claim 69 or 70, wherein, The thermally conductive material includes a metal, and the first heating element is an induction heater.

72. The system according to any one of claims 62 to 71, wherein, The sandblasting medium includes a plurality of particles.

73. The system according to claim 72, wherein, The plurality of particles have an average diameter in the range of 50 μm to 2 mm.

74. The system according to any one of claims 62 to 73, wherein The first heating element includes one or more of the following: a heated fluid source, an induction heater, a thermoelectric heater, or a heat pump.

75. The system according to any one of claims 62 to 74, wherein The second heating element includes one or more of the following: a heated fluid source, a thermoelectric heater, or a heat pump.

76. The system according to any one of claims 62 to 75, wherein, The second elevated temperature is lower than the first elevated temperature.

77. The system according to any one of claims 62 to 76, wherein The second elevated temperature is in the range of 30 °C to 100 °C.

78. The system according to any one of claims 62 to 77, further comprising: a drum configured to receive the object, and an actuator configured to rotate the drum while the filler directs the sandblasting medium towards the object.

79. The system according to any one of claims 62 to 78, further comprising a container configured to collect the sandblasting medium for reuse.

80. The system according to any one of claims 62 to 79, further comprising an additive manufacturing device configured to manufacture the object using the additive manufacturing process.

81. The system according to claim 80, wherein, The additive manufacturing process includes selective laser sintering.

82. The system according to any one of claims 62 to 81, wherein The object is an orthodontic appliance.

83. A method, comprising: receiving a dental appliance manufactured from a thermoplastic material using an additive manufacturing process; obtaining height data of the surface of the dental appliance via at least one sensor; and modifying the surface of the dental appliance by applying heat to the surface of the dental appliance using at least one heating element, wherein the at least one heating element is adjusted based on the height data.

84. The method according to claim 83, wherein, Modifying the surface of the dental appliance includes reducing the roughness of the surface of the dental appliance, reducing the porosity of the surface of the dental appliance, or a combination thereof.

85. The method according to claim 83 or 84, wherein, Modifying the surface of the dental appliance includes melting the surface of the dental appliance.

86. The method according to claim 85, wherein, The surface of the dental appliance is melted to a depth of no more than 50 μm.

87. The method according to any one of claims 83 to 86, wherein, Adjusting the at least one heating element includes adjusting one or more of the following: the position of the at least one heating element, the orientation of the at least one heating element, or the intensity of the at least one heating element.

88. The method according to any one of claims 83 to 87, wherein Adjusting the at least one heating element includes adjusting the vertical position of the at least one heating element relative to the dental appliance based on the height data. The method according to any one of claims 83 to 88, wherein, The at least one heating element includes a plurality of heating elements positioned at different positions relative to the dental appliance.

90. The method according to any one of claims 83 to 89, wherein, The at least one heating element includes one or more of the following: a flame generator, a plasma generator, or a corona generator.

91. The method according to any one of claims 83 to 90, wherein The at least one sensor includes an imaging device or a distance sensor.

92. The method according to any one of claims 83 to 91, further comprising: Identify a first appliance portion having a first height, Identify a second appliance portion having a second height different from the first height, Apply heat to the first appliance portion using a first set of heating parameters, and Apply heat to the second appliance portion using a second set of heating parameters.

93. The method according to any one of claims 83 to 92, wherein, The dental appliance is a palatal expander.

94. A system for processing an object manufactured by additive manufacturing, the system comprising: A sensor configured to generate height data; At least one heating element; At least one processor; And A memory operably coupled to the at least one processor and storing instructions which, when executed by the processor, cause the system to perform operations including: Receive height data of a surface of a dental appliance manufactured using an additive manufacturing process, and Apply heat to the surface of the dental appliance via the at least one heating element and based on the height data.

95. The system according to claim 94, wherein, The heat is configured to reduce the roughness of the surface of the dental appliance, reduce the porosity of the surface of the dental appliance, or a combination thereof.

96. The system according to claim 94 or 95, wherein, The heat is configured to melt the surface of the dental appliance.

97. The method according to claim 96, wherein, The surface of the dental appliance is melted to a depth of no more than 50 μm.

98. The method according to any one of claims 94 to 97, wherein, The at least one heating element includes one or more of the following: a flame generator, a plasma generator, or a corona generator.

99. The system according to any one of claims 94 to 98, wherein, The operations further include adjusting the at least one heating element based on the height data.

100. The system according to claim 99, wherein, Adjusting the at least one heating element includes adjusting one or more of the following: the position of the at least one heating element, the orientation of the at least one heating element, or the intensity of the at least one heating element.

101. The system according to any one of claims 94 to 100, wherein, The at least one heating element is movable.

102. The method according to any one of claims 94 to 101, wherein, The at least one heating element includes a plurality of heating elements positioned at different locations relative to the dental appliance.

103. The system according to any one of claims 94 to 102, wherein, The sensor includes an imaging device or a distance sensor.

104. A method, comprising: Receive an object manufactured using an additive manufacturing process; Obtain topography data of a surface of the object via at least one sensor; Modify the surface of the object by applying heat to the surface of the object based on the topography data.

105. The method according to claim 104, wherein, The additive manufacturing process includes selective laser sintering.

106. The method according to claim 104 or 105, wherein, The object is made of a thermoplastic material.

107. The method according to any one of claims 104 to 106, wherein, The object is made of a biocompatible material.

108. The method according to any one of claims 104 to 107, wherein, Modifying the surface of the object includes melting the surface of the object.

109. The method according to claim 108, wherein, The surface of the object is melted to a depth of no more than 50 μm.

110. The method according to any one of claims 104 to 109, wherein, Modifying the surface of the object includes reducing the roughness of the surface of the object.

111. The method according to any one of claims 104 to 110, wherein, Modifying the surface of the object includes reducing the porosity of the surface of the object.

112. The method according to any one of claims 104 to 111, wherein, Apply the heat to the surface of the object via at least one heating element.

113. The method according to claim 112, further comprising adjusting the at least one heating element based on the topography data.

114. The method according to claim 113, wherein, Adjusting the at least one heating element includes adjusting one or more of the following: the position of the at least one heating element, the orientation of the at least one heating element, or the intensity of the at least one heating element.

115. The method according to claim 113 or 114, wherein, The topography data includes height data, and adjusting the at least one heating element includes adjusting a vertical position of the at least one heating element relative to the object based on the height data.

116. The method according to any one of claims 112 to 115, wherein, The at least one heating element includes a plurality of heating elements positioned at different locations relative to the object.

117. The method according to claim 116, further comprising adjusting an intensity of each of the plurality of heating elements based on the topography data.

118. The method according to any one of claims 104 to 117, wherein, The at least one sensor includes an imaging device or a distance sensor.

119. The method according to any one of claims 104 to 118, further comprising: identifying a first object portion having a first surface topography, identifying a second object portion having a second surface topography different from the first surface topography, applying heat to the first object portion using a first set of heating parameters, and applying heat to the second object portion using a second set of heating parameters. The method according to any one of claims 104 to 119, further comprising receiving additional data indicative of at least one characteristic of the object, wherein, Applying the heat based on the additional data.

121. The method according to claim 100, wherein, The additional data indicates one or more of the following features: the type of the object, the geometry of the object, the type of material used to form the object, the properties of the material used to form the object, the location of the material used to form the object, or the initial surface features of the object.

122. The method according to claim 120 or 121, further comprising: receiving an identifier of the object, and using the identifier to obtain the additional data from a database. The method according to any one of claims 104 to 122, wherein, The object is an orthodontic appliance.

124. The method according to claim 123, wherein, The orthodontic appliance is a palatal expander.

125. A system for processing an object manufactured by additive manufacturing, the system comprising: a sensor configured to generate topography data; at least one heating element; at least one processor; and a memory operatively coupled to the at least one processor and storing instructions that, when executed by the processor, cause the system to perform operations including: receiving topography data from the sensor, wherein the topography data characterizes a surface of an object manufactured using an additive manufacturing process, and applying heat to the surface of the object via the at least one heating element and based on the topography data.

126. The system according to claim 125, wherein, The heat is configured to melt the surface of the object.

127. The system according to claim 126, wherein, The surface of the object is melted to a depth of no more than 50 μm.

128. The system according to any one of claims 125 to 127, wherein The heat is configured to reduce roughness of the surface of the object.

129. The system according to any one of claims 125 to 128, wherein, The heat is configured to reduce porosity of the surface of the object.

130. The system according to any one of claims 125 to 129, wherein, The at least one heating element includes one or more of the following: a flame generator, a plasma generator, or a corona generator.

131. The system according to any one of claims 125 to 130, wherein, The operations further include adjusting the at least one heating element based on the topography data.

132. The system according to claim 131, wherein, Adjusting the at least one heating element includes adjusting one or more of the following: a position of the at least one heating element, an orientation of the at least one heating element, or an intensity of the at least one heating element.

133. The system according to any one of claims 125 to 132, wherein, The at least one heating element is movable.

134. The system according to any one of claims 125 to 133, wherein, The at least one heating element includes a plurality of heating elements positioned at different locations relative to the object.

135. The system according to any one of claims 125 to 134, wherein, The at least one sensor includes an imaging device.

136. The system according to any one of claims 125 to 135, wherein, The at least one sensor includes a distance sensor.

137. The system according to any one of claims 125 to 136, wherein, The operation further includes: identifying a first object portion having a first surface topography, identifying a second object portion having a second surface topography different from the first surface topography, applying heat to the first object portion using a first set of heating parameters, and applying heat to the second object portion using a second set of heating parameters.

138. The system according to any one of claims 125 to 137, wherein, The operation further includes receiving additional data indicative of at least one characteristic of the object, wherein the heat is applied based on the additional data.

139. The system according to claim 138, wherein, The additional data indicates one or more of the following characteristics: the type of the object, the geometry of the object, the type of material used to form the object, the properties of the material used to form the object, the location of the material used to form the object, or the initial surface features of the object.

140. The system according to claim 139, wherein, The operation further includes: receiving an identifier of the object, and using the identifier to obtain the additional data from a database.

141. The system according to any one of claims 125 to 140, further comprising an additive manufacturing device configured to manufacture the object using the additive manufacturing process.

142. The system according to claim 141, wherein, The additive manufacturing process includes selective laser sintering.

143. The system according to any one of claims 125 to 142, wherein, The object is an orthodontic appliance.

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