Patent Description:
Although deposition processes such as 3D printing have been proposed for the direct manufacture of these appliances, at least some of the prior approaches to deposition manufacturing can be less than ideal. Work in relation to the present disclosure suggests that with at least some of the prior approaches to direct fabrication of dental appliances, there may be locations on the appliance that contain artifacts related to the direct fabrication process. These artifacts can result in rough or uneven surfaces on at least a portion of the appliance in some instances. Although these rough or uneven surfaces can be processed to smooth the dental appliance, this can increase the amount of time to manufacture an appliance and can result in non-uniformity of the appliance in at least some instances. Also, because teeth can have uneven surfaces, the prior methods and apparatus for deposition manufacturing may result in uneven or incomplete formation of the appliance in some instances. For example, teeth may have complex surfaces and at least some of the prior approaches to additive manufacturing may result in the formation of unsupported islands during deposition, which can result in defects in at least some instances.

With some approaches to additive manufacturing, an appliance may not be fully cured when removed from the additive manufacturing machine, and at least some of the prior approaches are less than ideally suited for removing the appliance from the additive manufacturing machine and for handling the appliance when removed. Also, because the appliance may not be fully cured when removed from the additive manufacturing machine, work in relation to the present disclosure suggests that some warpage may occur after the appliance has been removed from the additive manufacturing machine in at least some instances.

In light of the above, there is a need for improved methods of manufacturing dental appliances that overcome at least some of the above-mentioned limitations of the prior approaches.

<CIT> relates to a composite article useful in additive manufacturing that typically includes: (a) a base; (b) at least one three-dimensional lattice support connected to the base; (c) at least one three-dimensional object, the object having a bottom surface portion, a top surface portion, at least one upright segment, and optionally at least one overhanging segment (e.g., a bridging segment; a cantilevered segment, etc.); (d) interconnecting supports connecting (i) each the at least one overhanging segment to the three-dimensional lattice and/or (ii) each at least one upright segment to the three-dimensional lattice; and (e) optionally, but in some embodiments preferably, a plurality of elongate stand-off supports interconnecting the bottom surface portion of each the three-dimensional object to the base.

<CIT> relates to methods, systems, and devices for adjusting an arch of teeth. The document describes an appliance that includes a removable shell formed of a first material having a number of cavities formed therein, wherein the number of cavities are shaped to receive teeth of a patient, and an arch element extending from the removable shell in a lingual direction and across at least a portion of the arch width of the removable shell, wherein the arch element is designed to expand an arch of the teeth of the patient, wherein the arch element has a width specific to a stage of a treatment plan.

<CIT> relates toa tooth jaw orthotic device which comprises a first positioner, a second positioner and at least two elastic pieces. The first positioner is detachably mounted on a dental arch of an upper jaw of an oral cavity and is provided with at least two first connecting parts which are fixed on a left cheek side face and a right cheek side face of the first positioner respectively. The second positioner is a detachably mounted on a dental arch of a lower jaw of the oral cavity and is provided with at least two second connecting parts which are fixed on a left cheek side face and a right cheek side face of the second positioner respectively. The elastic pieces are respectively connected with the first positioner and the second positioner which are fixed at the dental arch of the upper jaw and the dental arch of the lower jaw respectively, to be used for driving the second positioner to move relative to the first positioner, so as to adjust a relative position between a lower jawbone of the second positioner and an upper jaw bone of the first positioner.

The methods, apparatuses and appliances of the present disclosure are directed to decreasing artifacts and warpage on appliances related to the manufacturing of dental appliances.

In some embodiments, a support is coupled to an appliance to decrease warpage. The support may comprise a plurality of extensions coupled to the appliance to decrease warpage. The extensions can be coupled to the appliance at one or more of many locations, such as on an occlusal surface, a wall, an edge or an interior of the appliance. In some embodiments, the extensions are coupled to walls of the appliance such as a buccal wall and a lingual wall, and the extensions can be coupled to the walls of the appliance near edges of the walls, such as a gingivally facing edges of the walls that are oriented toward the gingiva when the appliance is worn.

In some embodiments, a precursor to an appliance is formed, in which the precursor comprises the support coupled to the appliance. The support may comprise a holder and one or more extensions extending from the holder to the appliance. In some embodiments, the holder is formed on a retainer of the additive manufacturing machine such as a build plate. In some embodiments, the holder and support facilitate additional manufacturing steps while the holder and the appliance remain on the retainer. The holder can facilitate removal of the appliance from the retainer, handling of the appliance subsequent to removal, and provide structural support to the appliance subsequent to removal, as well as provide structural support that helps maintain appliance accuracy for usage.

In some embodiments, the plurality of extensions is coupled to an occlusal surface of the appliance with a gap between the occlusal surface of the appliance and the holder.

In some embodiments, an occlusal surface of the appliance is inclined at an angle relative to layers of material deposited during the additive manufacturing of the appliance. The layers of material indicate a direction of deposition of the layers during additive manufacturing of the appliance. The appliance can be inclined at any suitable angle relative to the direction of deposition.

In some embodiments, the support is formed, and a portion of the appliance is generated on the support prior to coupling the supported portion of the appliance to other supported portions of the appliance. This approach can be helpful where the dentition comprises inflections or other details that could otherwise result in the corresponding portion of the appliance not being appropriately coupled to the additive manufacturing machine, which could potentially result in a defect in the appliance.

In some embodiments, an edge along a wall of the appliance is coupled to a support structure at one or more locations to support the appliance during manufacturing. Coupling to the appliance along or near the edge can decrease interference from artifacts related to the deposition manufacturing of the appliance such as three-dimensional "3D" printing of the appliance. Coupling the appliance to the support near the edge allows the appliance to be readily decoupled from the support with fewer artifacts when the support has been decoupled from the appliance.

In some embodiments, the support comprises an extension coupled to a removal line. The removal line of the appliance corresponds to a location where the appliance has been separated from the support. The removal line can be located between the appliance the support between an occlusal surface of the teeth and a gingival line of the patient. In some embodiments, the removal line is located along at least a portion of gingival line, a cut line, or a terminal molar of the appliance. This approach can decrease the amount of post formation manufacturing of the appliance such as laser cutting or polishing. The support can be coupled to locations of the appliance corresponding to the removal line in order to decrease visibility of artifacts when the support has been decoupled from the appliance.

A better understanding of the features, advantages and principles of the present disclosure will be obtained by reference to the following detailed description that sets forth illustrative embodiments, and the accompanying drawings of which:.

The following detailed description provides a better understanding of the features and advantages of the inventions described in the present disclosure in accordance with the embodiments disclosed herein. Although the detailed description includes many specific embodiments, these are provided by way of example only and should not be construed as limiting the scope of the inventions disclosed herein.

The methods, apparatus and dental appliances disclosed herein are well suited for combination and incorporation with many known prior dental appliances and applications, such as an aligner for aligning a plurality of teeth, a retainer, a palatal expander, a bracket for placing attachments on a plurality of teeth, an attachment for coupling to teeth, a mandibular relocation appliance, a mandibular advancement appliance, a retainer with palatal support, a Theroux device such as a Theroux retainer, a nightguard, a functional appliance, and a 3D printed aligner thermoforming mold. The presently disclosed methods, apparatus and appliances are well suited for direct fabrication with deposition manufacturing, such as 3D printing, fused deposition modeling, stereo lithography (SLA), digital light projector (DLP) printing, continuous DLP, inkjet spray, and metal printing. Also, the presently disclosed methods and apparatus are well suited for the additive manufacturing of different materials onto a single appliance, such as inkjet printing with a plurality of different materials to print an appliance comprising a plurality of different materials. Although reference is made to the manufacture of dental appliances, the methods, apparatus and appliances disclosed herein are well suited for other fields, such as orthopedics, manufacturing jigs, and thermoforming molds.

<FIG> illustrates an exemplary dental appliance <NUM> and jaw <NUM> including a patient's teeth. <FIG> illustrates dental appliance cross-section <NUM> of appliance <NUM> as taken along line 1B-1B of <FIG>. The dental appliance <NUM> may be sized and shaped to fit over a plurality of teeth present in an upper or lower jaw. The dental appliance <NUM> may comprise any suitable material such as one or more of an organic material, polymer, inorganic material, metal, or ceramic, and combinations thereof. In some embodiments, dental appliance <NUM> comprises a plurality of teeth receiving cavities to hold the appliance on the teeth of the patient, for example with a retainer, palatal expander or aligner. In some embodiments, dental appliance <NUM> comprises a plurality of teeth receiving cavities and wall thickness and strength suitable for repositioning a plurality of teeth. In some embodiments the appliance <NUM> comprises a polymeric shell thickness of no more than about <NUM> millimeters, and, in some embodiments, the polymeric shell may thickness may be with a range from about <NUM> millimeter to about <NUM> millimeters. The appliance <NUM> such as a polymeric shell appliance may comprise a plurality of layers. As illustrated, the dental appliance <NUM> may have a generally U-shaped cross-section <NUM> to form one or more teeth receiving cavities <NUM> shaped to receive one or more teeth of a patient. The dental appliance <NUM> may comprise a thickness extending between an interior surface <NUM> shaped to receive a tooth and the exterior surface <NUM> facing away from the tooth. In some embodiments, the exterior surface <NUM> comprises an occlusal surface <NUM> to engage an opposing appliance or opposing teeth on an opposite side of the mouth. The occlusal surface <NUM> of appliance <NUM> generally extends along an occlusal plane <NUM>. The methods and apparatus disclosed herein may be used to print the dental appliance <NUM> with additive manufacturing.

Although the cross-section shown in <FIG> shows a portion of the appliance extending across the tooth, in some embodiments, the appliance extends between teeth. The dimensions of the cross-section of the appliance can vary in accordance with the shape of patient's teeth. For example, an exterior surface of the appliance may protrude outwardly near a midline of a tooth, and intrude slightly at mesial locations near a space between teeth. The methods, apparatus and appliances disclosed herein are well suited for addressing variations in geometry of a patient's dentition.

Although the embodiment of <FIG> illustrates a dental appliance in the form of an aligner, other types of dental appliances are suitable for use. For example, dental appliance <NUM> may comprise a retainer, a palatal expander, a bracket for placing attachments on a plurality of teeth, an attachment for coupling to teeth, a nightguard, a functional appliance, or a 3D printed aligner thermoforming mold.

The methods and apparatus disclosed herein are well suited for combination with many types of additive manufacturing such as three-dimensional ("3D") printing. At least some additive manufacturing machines and 3D printers comprise an internal retainer, such as a platform, upon which the part is formed. While the 3D printer can be configured in many ways, in some embodiments the retainer moves while the part is formed and light is directed to a curable material that solidifies for form the part in response to light. As the deposition process continues, the retainer moves relative to the print head to deposit additional layers. The retainer and print head of the 3D printer can be oriented in many ways, for exampling in a vertical orientation, a horizontal orientation or an oblique orientation. For example, the print head can be located beneath the retaining surface. In general, the 3D printing process prints a single substantially planar layer at a time that is generally parallel to the retainer surface, such as a platform. After printing a layer, the distance between the retaining surface and print head increases to print a new layer. The retaining surface may move away from the print head, or vice versa, and combinations thereof. In general, each successive layer is built on top of the previous layer. The layers are successively deposited along a direction of deposition, which is substantially perpendicular to each of the deposited layers.

<FIG> illustrates an appliance precursor <NUM>, in accordance with some embodiments. The dental appliance precursor <NUM> can be printed in layers along a direction of deposition <NUM>. The layers are generally perpendicular to the direction of deposition <NUM>. While the direction of deposition can be oriented in many ways, the layers can be perpendicular to an occlusal plane <NUM> of the dental appliance <NUM>. The dental appliance precursor <NUM> comprises a support <NUM> and the appliance <NUM>. The support <NUM> comprises a holder <NUM> and one or more extensions, e.g. a plurality of extensions <NUM>. The plurality of extensions <NUM> extend from the holder <NUM> to the dental appliance <NUM>, and support the appliance during the printing process. The holder <NUM> may be printed directly to a retaining surface of an additive manufacturing device such as a three-dimensional printer. In some embodiments, the dental appliance precursor <NUM> may be printed vertically along the direction of deposition <NUM> and extend downward as shown in <FIG>. In other embodiments, the dental appliance precursor <NUM> may be printed vertically from a retaining surface and extend upward. The direction of deposition can extend along any suitable direction, e.g. horizontally, vertically, or obliquely to the horizontal and vertical directions.

The holder <NUM> can be printed directly on the retainer of the 3D printer. In some embodiments, the plurality of extensions <NUM> is printed on the holder <NUM> and extend from the holder <NUM> to the dental appliance <NUM>. The embodiment of <FIG> includes a plurality of three extensions <NUM>. Outer extensions 113a couple the holder <NUM> to an exterior surface of the dental appliance at a location corresponding to a posterior surface <NUM> of a posterior tooth receiving cavity <NUM> shaped to receive a posterior tooth such as a molar. Inner extension 113b couples the holder <NUM> to an exterior surface of the dental appliance <NUM> at a location corresponding to a lingual edge <NUM> of an incisor of the dental appliance <NUM>. The extensions <NUM> may comprise a plurality of perforations <NUM> to reduce the amount of material forming the support <NUM>.

The one or more extensions <NUM> can be configured in many ways and may comprise one or more of a uniform thickness, a non-uniform thickness, voids within the extension, a hollow portion within the extension, a filled in portion within the extension, a solid filled in portion without voids, or a gradient thickness from the holder to the dental appliance.

In some embodiments, the holder <NUM> extends between the outer extensions 113A and 113B with the inner extension 113B coupled to the holder <NUM> there between. The plurality of extensions may define a plurality of gaps between the inner extension and the outer extension. The holder may comprise sufficient thickness to provide structural strength to allow handling and removal from the retainer of the 3D printer. Although the holder <NUM> is shown as a continuous single piece extending between the outer extensions 113A, in some embodiments, the holder comprises a plurality of separate pieces to couple the extensions to the appliance. The plurality of separate pieces can be configured in many ways, and may comprise one or more of variable thickness, perforations, or a separate material from the appliance in order to couple the extensions to the appliance.

With the additive manufacturing process as described herein, the holder <NUM> is printed on retaining surface of an additive manufacturing machine. The holder comprises a surface in contact with the retainer of the 3D printer while the layers of the appliance are deposited. One or more additive layers of the holder <NUM> contacts the retaining surface of the additive manufacturing machine. The number of layers of the holder <NUM> in contact with the retaining surface of the additive manufacturing machine can be related to whether the retainer surface of the 3D printer is inclined relative to the direction of deposition <NUM> of the plurality of layers. The holder may comprise a plurality of layers and sufficient thickness to provide strength to support the appliance during the additive manufacturing process and handling subsequent to removal from the 3D printer.

The holder can be sized and shaped in many ways. In some embodiments a portion of the holder comprises a removal structure shaped to facilitate removal of the holder from the retention structure, e.g. removal of the holder from a surface of a build platform. The removal structure of the holder may comprise one or more of an inclined surface, an overhang or other channel shaped to facilitate removal of the holder from the build platform. Providing a removal structure on the holder can facilitate removal of the holder and decrease potential stresses and possible damage to the appliance supported with the holder and the extensions of the support. For example, on the manufacturing floor, a straight edge can be advanced along a surface of the build platform between the surface of the build platform and the removal structure to separate the holder from the surface of the build platform. The straight edge can be advanced manually by an operator or with automation, for example robotically.

The plurality of extensions <NUM> is printed on the holder <NUM> so as to extend to the appliance <NUM>. The plurality of layers forms the appliance precursor <NUM> on the one or more extensions of support <NUM>, e.g. the plurality of extensions <NUM>. The precursor <NUM> may then undergo further processing to become the appliance <NUM>. In some embodiments, the dental appliance precursor comprises an intermediate part formed prior to completion of the finished dental appliance <NUM>, which finished dental appliance is suitable for placement on a patient's teeth.

The additive manufacturing process may result in a dental appliance precursor <NUM> that may be processed further to obtain a finished dental appliance <NUM>. For example, the extensions <NUM> may be removed from the dental appliance precursor <NUM> prior to use by a patient. Once the supports <NUM> have been removed, locations where the supports were previously attached to the dental applicant may be polished or otherwise treated to obtain a finished surface for the dental appliance. Other processes may be used such as securing additional material to the dental appliance, sterilization, and/or heat treatment.

Some embodiments of the present disclosure are directed to reducing the time and complexity of the processing of the appliance after being formed, the amount of material used to manufacture the appliance, the number of local minima within tooth receiving cavities and corresponding supporting extensions, and speeding up the overall 3D printing process. A reduction in the number of extensions <NUM> and associated coupling points to the appliance <NUM> may provide a faster post 3D printing process. The methods and apparatus disclosed herein can provide a more efficient removal of the support and extensions and reduce reliance on surface finishing while maintaining mechanical and aesthetic integrity of the resulting dental appliance <NUM>.

The methods and apparatus described herein may use existing technology to remove the extensions <NUM>, such as laser trimming. However, because the supports <NUM> are coupled to the dental appliance <NUM> at specific locations along the edge of the appliance, there may less finishing of the surfaces of the dental appliance <NUM>. For example, the amount of polishing time and surface area can be reduced. The dental appliance precursor <NUM> manufactured from the described printing process may result in easily removed extensions <NUM> that may be removed on a mass manufacturing scale without requiring extensive surface finishing. Thus, it may be possible to print a dental appliance precursor <NUM>, remove the extensions <NUM>, and have the dental appliance <NUM> proceed to packaging without significant additional manufacturing processes.

Supporting the appliance along the walls with extensions can reduce the reliance supports coupled to interior and exterior surfaces of the appliance. Once removed from <NUM>-D printer, this printed dental appliance precursor <NUM> can be laser trimmed to fit without surface finishing to remove surface support marks. Use of the removal line such as a gingival cut line on the dental appliance precursors is advantageous from a processing standpoint, as well as for the final product. In some embodiments, having supports only in contact with the removal line of the appliance <NUM> gives a clear, identifiable indication of where the separation is supposed to occur, provides improved tolerance as to how the supports are cleaned, and allows a mill or laser cutter to remove the supporting extensions.

<FIG> illustrates a detailed view of the inner extensions 113b coupled to an edge of the dental appliance <NUM> at a posterior surface <NUM>.

<FIG> illustrates a detailed view of the inner extension 113b attached to an edge of the dental appliance <NUM> along a lingual edge <NUM>.

As shown in <FIG> and <FIG>, the extensions <NUM> may be attached to the edges of the dental appliance <NUM> along a removal line <NUM>. The removal line <NUM> may mark a transition from the support <NUM> to the dental appliance <NUM>. In some embodiments, the removal line <NUM> may extend along a gingival line. Alternatively or in combination, the removal line may extend along a line between the occlusal surface and a gingival line corresponding to a gingival line of a specific patient. The removal line can be configured in many ways, and may comprise a visible marker for cutting the appliance with optical guidance, such as with laser or other cutting as described herein.

In some embodiments, the removal line <NUM> comprises a weakened portion <NUM> of the dental appliance precursor <NUM> extending over a region between the dental appliance <NUM> and the extensions <NUM>. The weakened portion <NUM> may include features such as a plurality of perforations, a channel, a plurality of channels, a groove, a plurality of grooves, a cavity, a plurality of cavities, a reduced cross-sectional area compared to the appliance, and a weaker material compared to the dental appliance <NUM> or the extensions <NUM>. In some embodiments, the removal line <NUM> comprises substantially the same thickness as the appliance, such as a similar wall thickness and cross-sectional area as the wall of the appliance near the removal line. For example, in the embodiments of <FIG> and <FIG>, a plurality of perforations arranged in a line forms the removal line <NUM>. The weakened portion of material may ease the separation between the support <NUM> and the dental appliance <NUM>.

The use of different materials can facilitate removal of the appliance along the removal line. In some embodiments a material different from the appliance material is deposited along or near the removal line to facilitate separation of the appliance from the extension near the removal line. For example, the appliance can be formed with a plurality of deposition materials from an inkjet printer, in which the printer comprises an appliance material and a weaker removal material for placement near the removal line.

After printing the dental appliance precursor <NUM>, the support <NUM> comprising extensions <NUM> may be removed from the dental appliance <NUM> at the removal line <NUM>, for example by tearing the dental appliance precursor <NUM> at the removal line <NUM>. Alternatively or in combination, the removal line <NUM> may provide an easily identifiable area for cutting using conventional techniques such as a laser cutter. Additional post separation processes can be performed, such as polishing along the separated edge.

<FIG> illustrates a detailed view of a wall portion of the dental appliance precursor <NUM> near the removal line <NUM> corresponding to an edge of appliance <NUM>. The detailed view of <FIG> illustrates a plurality of deposition layers <NUM>. The plurality of deposition layers comprises a first plurality of layers <NUM>, a second plurality of layers <NUM>, and a third plurality of layers <NUM>. The first plurality of layers <NUM> corresponds to an extension of the one or more extensions <NUM> of the support <NUM> extending from the holder. In some embodiments, the first plurality of layers <NUM> comprises the holder <NUM>. In some embodiments, over <NUM> layers can be used to form an appliance, and the first plurality of layers may comprise any suitable number of layers.

The second plurality of layers <NUM> corresponds to a portion of the extension <NUM> and one or more portions of dental appliance <NUM>. A layer <NUM> of the second plurality of layers extends through the extension <NUM>, a first portion 106a of the appliance <NUM>, and a second portion 106b of the appliance <NUM>. A gap in the appliance <NUM> extends along layer <NUM> between the first portion 106a and the second portion 106b of the appliance <NUM>. Although layer <NUM> is shown extending between first portion 106a and second portion 106b, in some embodiments, the extension <NUM> does not extend between the first portion and the second portion.

The removal line <NUM> extends to a first local minimum 128a and a second local minimum 128b. The extension <NUM> is coupled to the first portion 106a of appliance <NUM> at the fist local minimum 128a and second portion 106c of the appliance <NUM> is coupled to the second local minimum 128b.

The third plurality of layers <NUM> corresponds to a third portion 106c of the dental appliance <NUM>. A layer <NUM> of the third plurality of layers <NUM> extends along the third portion 106c of the appliance <NUM>. The third portion 106c of the appliance couples the first portion 106a of the appliance to the second portion 106b of the appliance. In some embodiments, the third portion 106c of the appliance comprises the third plurality of layers, and the third plurality of layers couples to the second plurality of layers so as to couple the first portion 106a to the second portion 106b with the third portion 106c of the appliance <NUM>. The coupling can allow the appliance to be removed from the one or more extensions <NUM>, such that the first portion 106a remains connected to the second portion 106b.

The removal line <NUM> is formed between the transition from one or more of the extensions <NUM> to the dental appliance <NUM>. The thickness of a location in any individual layer may be controlled by adjusting the width of the appliance and the amount of cured material added at that location, and the removal line may correspond to a change in thickness at the transition between the appliance and the extension.

The direction of deposition <NUM> is show extending approximately perpendicular to each of the plurality of layers. The first local minimum 128a and the second local minimum 128b of the appliance is shown in relation the direction of deposition <NUM>. Although two local minima are shown, in some embodiments one local minimum is coupled to the wall of the appliance with the extension <NUM>. The extension can support the appliance at the local minimum when the appliance <NUM> and precursor <NUM> have been partially formed, for example formed to a layer <NUM> of the second plurality of layers <NUM>. The first portion 106a of appliance <NUM> near the first local minimum 128a may not be directly connected to other portions of appliance <NUM> when layer <NUM> has formed the portion 106a of the appliance. The extension <NUM> supports the first portion 106a of the appliance <NUM> near the first local minimum 128a to maintain the position of the portion of the appliance near local minimum prior to directly connecting the portion of the appliance. The extension <NUM> may similarly support the second portion 106b near the second local minimum 128b. Although the extension is shown to extend between the fist local minimum and the second local minimum, in some embodiments voids or other gaps can be placed in extension <NUM> between the first local minimum and the second local minimum.

An additive manufacturing process will typically print material onto existing cured material. Depending on the type of material and the printing device, each successive layer can typically extend laterally to the direction of deposition as far as the immediately preceding layer plus a small amount of overhang. Thus, a printer can be limited in the rate of increase in surface area size of successive layers. The increasing size of successive layers can define a corresponding angle in relation to the direction of fabrication (e.g. a direction of deposition), and the extension can be sized to couple to the wall of the appliance along removal line <NUM> along any suitable distance. Additionally, a 3D printer may be unable to print features that correspond to local minimum without utilizing an extension to support the feature of the appliance at the local minimum, so as to inhibit the formation of islands. Work in relation to the present disclosure suggests that unsupported local minima can be related to the formation of islands, and that the presently disclosed methods and apparatus can substantially decrease and even inhibit island formation during direct fabrication of the appliance <NUM>.

Thus, one or more extensions as described herein may be added to support locations that would otherwise be unsupported, such as the first local minimum 128a and the second local minimum 128b. In another example, if the dental appliance <NUM> of <FIG> were being printed from a gingiva end <NUM> toward an occlusal surface <NUM>, local minimum <NUM> could rely on an extension to support it. The extension <NUM> would extend into a tooth receiving cavity and couple to the dental appliance at a local minimum <NUM>.

Although <FIG> makes reference to a removal line <NUM> in the context of a removal line, local minima and layers corresponding to an edge of the appliance, the plurality of layers and removal line can be used alternatively or in combination with other embodiments disclosed herein. In some embodiments, the first local minimum 128a, the second local minimum 128b, and removal line <NUM> correspond to surface profile of an occlusal surface of an appliance, in which the local minima of the occlusal surface are supported with the extensions and the extensions subsequently removed from the occlusal surface as described herein.

Although extensions into a tooth receiving cavity to support a local minimum can result in more finishing than would be ideal, the methods and apparatus disclosed herein can be configured to decrease reliance on extension that extend into teeth receiving cavities, for example by determining a suitable angle of inclination of the appliance in relation to the plurality of deposition layer and the direction of deposition. Work in relation to embodiments suggests that inclining the occlusal surface of appliance <NUM> relative to plurality of layers can reduce or even eliminate local minima within teeth receiving cavities, which can decrease the number of removal locations and corresponding finishing subsequent to separation of the appliance from the support.

In some embodiments, the appliance is printed in an orientation that decreases the number of local minima and corresponding extensions coupled thereto. For example, the dental appliance <NUM> of <FIG> could be printed with the plurality of deposition layers inclined relative to an occlusal plane of the appliance. The angle of inclination can be within a range from about <NUM> degrees to about <NUM> degrees, and optionally within a range from about <NUM> degrees to about <NUM> degrees. The plurality of layers can be inclined relative to the occlusal plane in many ways. For example, the dental appliance <NUM> could be printed from a posterior portion of the appliance toward an anterior portion of the appliance, or from an anterior portion of the appliance toward a posterior portion of the appliance. Alternatively or in combination, the appliance can be printed from a labial surface toward a lingual surface.

<FIG> illustrates an example of a completed dental appliance precursor <NUM> printed in a direction of deposition <NUM> such that the layers of deposition are inclined in relation to the occlusal plane. The embodiment of <FIG> has an angle between the occlusal plane <NUM> and the layers to reduce the number of local minimums requiring extensions <NUM>. In some embodiments, the angle between the occlusal plane <NUM> and the layers is from about <NUM> degrees to about <NUM> degrees. In some embodiments, the angle between the occlusal plane and the layers is from about <NUM> degrees to about <NUM> degrees. In still other embodiments, the angle between the occlusal plane and the layers is from about <NUM> degrees to about <NUM> degrees.

<FIG> illustrates the dental appliance precursor <NUM> of <FIG> separated from the support into to provide a separate dental appliance <NUM>.

<FIG> illustrates the support <NUM> of the dental appliance precursor <NUM> separated from the appliance. As shown in <FIG> and <FIG>, the support <NUM> of the dental appliance precursor <NUM> may comprise extensions <NUM> in order to print a local minimum of the appliance that lies below the adjacent portions of the appliance with reference to the direction of deposition.

<FIG> illustrates an example of a completed dental appliance precursor <NUM> showing a dental appliance <NUM> coupled to a support <NUM> comprising one or more extensions <NUM>. In this embodiment, the layers are printed in a gingival to occlusal direction of deposition <NUM>, in which the layers of deposition extend approximately parallel to the occlusal plane <NUM> of the dental appliance <NUM>. The layers of deposition can extend to within about +/- <NUM> degrees of parallel to the occlusal plane, for example. In this example, the precursor <NUM> can be printed downward from the holder <NUM> with each successive layer being printed beneath the immediately preceding layer. The dental appliance comprises a buccal wall <NUM> and a lingual wall <NUM>. An interior surface of the buccal wall <NUM> and the lingual wall <NUM> may form cavities for receiving a plurality of teeth. The support <NUM> comprises an extension <NUM> printed as a wall extending downward from the holder <NUM> to the buccal wall <NUM> and the lingual wall <NUM> of the dental appliance <NUM>, such that each successive layer is printed below the immediately preceding layer, for example. A removal line <NUM> couples the support <NUM> to the dental appliance <NUM>. The removal line <NUM> may comprise any of the removal lines as described herein. In some embodiments, a portion of the removal line <NUM> may remain after the support <NUM> is removed from the dental appliance precursor <NUM> to form a removal edge. The removal edge may extend at least partially between an interior side of the buccal wall and/or the lingual wall and an exterior side of the buccal wall and/or the lingual wall. The removal edge may traverse a plurality of layers of the dental appliance <NUM>. The removal edge may protrude exteriorly from the dental appliance <NUM> with different distances relative to a layer line.

<FIG> illustrates an example of a completed dental appliance precursor <NUM> similar to the example of <FIG>. In the example of <FIG>, the precursor <NUM> is printed upward from the holder <NUM> with each successive layer being printed on top of the immediately preceding layer. In this embodiment, the layers are printed in a gingival to occlusal direction of deposition <NUM>, in which the layers of deposition extend approximately parallel to the occlusal plane <NUM> of the dental appliance <NUM>. The layers of deposition can extend to within about +/- <NUM> degrees of parallel to the occlusal plane, for example. Although reference is made to an angle within about +/- <NUM> degrees of parallel to the occlusal plane, any suitable angle can be used to decrease local minima, e.g. minimize local minima, as described herein. Each layer may be printed in a plane that is generally parallel to an occlusal plane of the dental appliance <NUM>. The support <NUM> comprises a wall that extends from the holder <NUM> to the dental appliance <NUM>. The wall comprises one or more extensions <NUM> between the holder <NUM> and the appliance <NUM>. The support includes a plurality of perforations <NUM> to reduce the amount of material used to print the support <NUM>. The support <NUM> and the dental appliance <NUM> are coupled at a lingual edge <NUM>, a buccal edge <NUM>, and an anterior edge <NUM> of the dental appliance <NUM>. A removal line <NUM> is formed between the support <NUM> and the dental appliance <NUM> and may, in some embodiments, occur at a gingival line of the dental appliance <NUM>. Alternatively or in combination, removal line <NUM> can be located above the gingival line, for example located between the occlusal surface and the gingival line.

<FIG> illustrates a top view of the dental appliance <NUM> of <FIG> showing the occlusal surface <NUM> of the dental appliance <NUM>. In some embodiments, the dental appliance <NUM> may comprise voids <NUM> where no material is printed. For example, voids <NUM> may exist in locations where the dental appliance <NUM> would extend below the surrounding area, e.g. a local minimum along the direction of additive layers. In order to decrease printing additional extension supports within the dental appliance, voids <NUM> may be provided in these areas to decrease post printing processing. For example, with some dental appliances, portions of the occlusal surface <NUM> may not significantly impact the performance of the appliance and may therefore be left unprinted.

<FIG> illustrates an embodiment of a dental appliance precursor <NUM> in which the deposition layers are printed at an angle relative to the occlusal plane <NUM>. <FIG> illustrates an anterior view of the embodiment of the dental appliance precursor <NUM> of <FIG> showing the angle between the occlusal plane <NUM>. The deposition layers extend approximately perpendicularly to the direction of deposition <NUM>. In the embodiment of <FIG>, the occlusal surface <NUM> at the anterior end <NUM> of the dental appliance <NUM> is at a different height relative to the holder <NUM> compared to a height of the occlusal surface <NUM> at the posterior end <NUM> relative to the holder <NUM>. In some embodiments, the appliance can be inclined relative to the direction of deposition <NUM>, such that a first posterior end 131a of the appliance is separated from the holder <NUM> with a first distance, and a second posterior end 131b is separated from the holder <NUM> with a second distance different from the first distance. The anterior end of the appliance can be separated from the holder <NUM> with a third distance between the first distance and the second distance. Inclining the occlusal plane <NUM> of the dental appliance <NUM> in relation to the deposition layers as described herein may reduce the number of local minima which may in turn reduce the number of extensions that are used. Inclining the appliance may also reduce the cross-sectional surface area where extensions contact the appliance along the removal edge. In some embodiments, the angle between the occlusal plane and the layers is from about <NUM> degrees to about <NUM> degrees. In some embodiments, the angle between the occlusal plane and the layers is from about <NUM> degrees to about <NUM> degrees. In still other embodiments, the angle between the occlusal plane and the layers is from about <NUM> degrees to about <NUM> degrees.

<FIG> shows an example schematic of an additive manufacturing device, such as 3D printer <NUM>. The 3D printer <NUM> comprises a print head <NUM> and a retaining surface <NUM>. The 3D printer comprises a processor <NUM>, which comprises a central processing unit (CPU) <NUM> and memory <NUM>. The processor <NUM> can be configured with instructions to print the appliance as described herein. The instructions may comprise instructions to print each of the plurality of layers along a direction of deposition in order to form the precursor appliance as described herein. During the printing process the print head <NUM> prints each of the plurality of layers and the separation distance between the print head and the retainer <NUM> increases.

The 3D printer receives a digital data set corresponding to the shape and orientation of the appliance precursor in relation to the direction of deposition as described herein. While the digital data set can be configured in many ways, in some embodiments the digital data set defines one or more of voxels, contours, infills, hatching, or jump strategies, corresponding to the shape and orientation of the appliance in relation to the direction of deposition. The digital data set may correspond to a stage of treatment of the appliance. In some embodiments, the digital data set defines a plurality of appliances to be manufactured together on the retaining surface <NUM>, in which each of the plurality of appliances corresponds to a different stage of treatment of the patient.

Although <FIG> shows the 3D printer <NUM> in a vertical orientation a print head <NUM> located above a retaining surface <NUM>, other 3D printer types are suitable for use with the disclosed embodiments. For example, the print head <NUM> can be located beneath the retaining surface <NUM>. In general, the 3D printing process prints a single planar layer at a time that is approximately parallel to the retaining surface <NUM>. After printing a layer, the print head <NUM> may move away from the retaining surface <NUM> to print a new layer. Alternatively or in combination, the retaining surface <NUM> may move away from the print head <NUM>. Each successive layer is built on the previous layer, for example on top of or beneath the previous layer. Although the 3D printer <NUM> is show in a vertical orientation, other orientations can be used to generate the appliance precursor <NUM> as described herein, for example horizontal or oblique orientations.

The additive manufacturing device may comprise one or more components as described in <CIT>.

In some embodiments, a processor is configured with instructions for a user to design an appliance, identify and define features of the appliance and precursor. For example, a model of the precursor can be shown on a display, and the features of the appliance and support determined. Alternatively or in combination, some of these design steps can be automated. The additive manufacturing device may comprise one or more components as described in <CIT>, such as the user interface, treatment planning software, user interface, scanner, and appliance materials described therein.

<FIG> shows a schematic of a method <NUM> for printing a dental appliance precursor in accordance with some embodiments. At step <NUM>, a first plurality of layers of material is deposited on a retention surface. For example, in some embodiments 3D printer <NUM> may print a first layer of material or a plurality of layers on retaining surface <NUM>. Additional layers of material are deposited on the first layer of material. There can be several layers of material deposited on the support prior to forming the appliance. For example, several layers can be deposited prior to forming the first plurality of layers of material may correspond to first plurality of layers <NUM> of <FIG>.

At step <NUM>, a second plurality of layers of material is deposited on the first plurality of layers to form an extension of a support and a first portion of a dental appliance. For example, in some embodiments 3D printer <NUM> may print a second plurality of layers on the first plurality of layers. The second plurality of layers may correspond to the second plurality of layers <NUM> of <FIG>.

At step <NUM>, a third plurality of layers are deposited on the second plurality of layers to form a second portion of the dental appliance on the extension of the support with the second portion of the appliance coupled to the second layers of material along an edge of the second portion of the dental appliance. For example, in some embodiments, 3D printer <NUM> may print a third plurality of layers of material to the second plurality of layers of material. The third plurality of layers may correspond to third plurality of layers <NUM> of <FIG>.

<FIG> shows a schematic of a method <NUM> for printing a plurality of supports. At step <NUM>, a direction of deposition for a plurality of layers along a dental appliance is determined. For example, a computing device such as controller <NUM> or a separate computer, may determine a planar direction for printing a dental appliance such as dental appliance <NUM>. At step <NUM>, a plurality of local minima of the dental appliance along the direction of deposition is identified. For example, a computing device such as controller <NUM> or a separate computing device may identify a local minimum such as local minimum <NUM> of <FIG>. At step <NUM>, a plurality of support structures is arranged to couple the plurality of local minima. For example, a computing device such as controller <NUM> or a separate computing device may arrange to build a plurality of supports such as extensions <NUM> to couple the local minima to a base surface such as retaining surface <NUM>.

In some embodiments, the support comprises a wall coupled to the holder and the appliance. The wall can be configured in many ways, and may comprise a variable thickness or a substantially uniform thickness, for example. In some embodiments, the wall comprises apertures, e.g. perforations, which can facilitate the removal of fluids, such as uncured material and cleaning fluids. The wall may comprise stiffness to add strength, which can facilitate removal of the precursor appliance from the build plate and handling of the precursor appliance after removal. In some embodiments, stiffeners extend between walls of the support to strengthen the walls. While stiffeners can be configured in many ways, in some embodiments, the stiffeners comprise one or more of struts or trusses extending between the walls of the support to add strength. In some embodiments, the stiffeners are arranged in a generally triangular pattern to provide strength to the walls. In some embodiments, two internal stiffeners extend between the walls of the support to define two legs of a triangle, and the portion of the wall extending between the two stiffeners define a third leg of the triangle.

In some embodiments, the internal stiffeners can be viewed through one or more of the apertures. Although reference is made to internal stiffeners, in some embodiments stiffeners such as trusses can be fabricated exterior to the walls.

In some embodiments, the walls can facilitate the detection of warpage, which can be helpful during quality control procedures of the precursor and the appliance. Also, the support comprising walls connected with internal stiffeners may allow removal of the precursor appliance more quickly from the build plate, which can decrease the manufacturing time in some instances.

In some embodiments, the support comprises walls. Work in relation to the present disclosure suggests that walls coupled to each other with stiffeners can allow the walls to be thinner, which can decrease the amount of material used. One of ordinary skill in the art can conduct simulations such as finite element analysis to determine the appropriate thickness of the wall and configuration of the internal trusses.

In some embodiments, an overall angle of inclination of the appliance in relation to a build platform is determined as described herein, and the shape profile and structure of the support and walls determined in response to the angle of inclination. In some embodiments, the appliance is supported with the walls along an edge of the appliance as described herein. The appliance can be removed from the support and finished, for example by removing the support, surfacing finishing and maintaining mechanical and aesthetic integrity of the 3D printed appliance.

The appliance can be removed from the support in many ways as described herein, such as laser trimming along the edge of the appliance, which can decrease reliance on finishing the surface of the appliance. Although reference is made to laser trimming, in some embodiments, the appliance is coupled to the walled support along a removal edge comprising a weakened portion as described herein, so as to facilitation removal.

In some embodiments, the walled support comprises internal channels to facilitate removal uncured liquid resin or other fluid to drain or flow away from the walled support and appliance supported thereon. The channels may be configured to work with the overall structure and the direction of intended flow of the material being removed during post processing.

Work in relation to the present disclosure suggests that the walled support with internal stiffeners may improve print accuracy, which may be related to the strength of the walled support.

<FIG> shows an appliance precursor <NUM>, in which the support <NUM> comprises a wall <NUM> coupled to the holder <NUM> as described herein. The wall <NUM> comprises a plurality of apertures <NUM> to allow fluid to drain from an interior of the wall <NUM>. While the wall can be formed in many ways, in some embodiments the wall supports the appliance on a lingual side of the appliance and a buccal side of the appliance <NUM>. The appliance <NUM> can be supported along a removal edge as described herein, so as to decrease additional manufacturing steps as described herein. The precursor appliance <NUM> can be manufactured in a direction of deposition <NUM> extending from holder <NUM> to appliance <NUM>. In some embodiments, a plan <NUM> defines a cross-section through the appliance precursor <NUM>. A plurality of reference locations along the plane are shown, including first location <NUM>, a second location <NUM> and third location <NUM>.

<FIG> shows a cross-sectional view of the appliance precursor of <FIG> showing a cross-sectional view of the walled support along the plane <NUM>. The plane <NUM> extends through the precursor appliance <NUM> and defines a cross-sectional profile <NUM> of the precursor appliance <NUM> and extends through a portion of the wall <NUM>. The wall <NUM> of the support <NUM> comprises a buccal wall <NUM> and a lingual wall <NUM>, which define an interior <NUM> of the support located between the two walls. In some embodiments, the interior <NUM> comprises stiffeners extending between the two walls. In some embodiments, the plurality of apertures <NUM> extend through the buccal wall <NUM> and the lingual wall <NUM> so as to allow fluid removal from the interior <NUM>.

The cross-sectional profile <NUM> can be configured in many ways. In some embodiments, the cross-sectional profile <NUM> corresponds to a profile of appliance <NUM>, such as an edge profile corresponding to a removal line as described herein. In some embodiments, the walls extend with cross-sectional profile <NUM> between the holder <NUM> and appliance <NUM>. The buccal wall <NUM> and the lingual wall <NUM> extend along the direction of deposition <NUM>, and the walls can be manufactured with the deposition of layers as described herein. In some embodiments, the cross-sectional profile <NUM> of the walls near holder <NUM> corresponds to the removal profile of the appliance <NUM>, such that the buccal wall <NUM> and the lingual wall <NUM> extend in a substantially straight path along the direction of deposition <NUM>. Alternatively or in combination, the walls and profile <NUM> can vary, and may comprise other shapes other than substantially straight, such as with columns, external bracing or other structures to add support.

<FIG> shows a view of internal stiffeners <NUM> through one or more apertures <NUM> of a walled support of an appliance precursor as in <FIG>. In some embodiments, the internal stiffeners <NUM> are visible through the plurality of apertures, which can facilitate manufacturing and allow quality control procedures with respect to the stiffeners of support <NUM>. The internal stiffeners <NUM> can be configured with any suitable shapes and orientations relative to one or more of the appliance or the direction of deposition, and may comprise one or more of struts, trusses, rods, bars, bracing, or mesh. Alternatively or in combination, the internal stiffeners may comprise a completely filled-in interior of the wall along at least a portion of the interior, and in some embodiments the interior is completely filled-in to add stiffness.

<FIG> shows an internal view of stiffeners <NUM> as in <FIG> extending along the interior <NUM> of the walled support <NUM> between the buccal wall <NUM> and the lingual wall <NUM>.

<FIG> shows another view of internal stiffeners <NUM> as in <FIG>. The internal stiffeners <NUM> extending between buccal wall <NUM> and lingual wall <NUM> can be arranged in many ways. In some embodiments, each of the plurality of stiffeners extends from a first location on a first wall to a second location on a second wall. The relative positions of the first location and the second location can be arranged in many ways. For example, the first location and the second location may correspond to a shortest distance between the buccal wall <NUM> and the lingual wall <NUM>. Alternatively or in combination, the plurality of stiffeners can be inclined relative to each other. Work in relation to the present disclosure suggests that inclining the stiffeners relative to each other can add stiffness and strength to the walls of the support. In some embodiments, two stiffeners couple to a first wall at first locations separated by a first distance and couple to a second wall at second locations separated by a second distance greater than the first distance. The amount by which the second distance is greater than the first distance can be related to an angle of inclination between the two stiffeners.

In some embodiments, the plurality of stiffeners is arranged so as to define a generally triangular arrangement <NUM> of the plurality of stiffeners <NUM>. In some embodiments, a first stiffener <NUM> extends from a first location <NUM> on a first wall to a second location <NUM> on a second wall, and a second stiffener <NUM> extends from the second location <NUM> on the second wall to a third location <NUM> on the first wall. A portion <NUM> of the first wall extends between the first location and the third location, so as to define a generally triangular arrangement of the plurality of stiffeners. The distance between the first location and the third location is related to the angle of inclination between the first stiffener and the second stiffener. In some embodiments, the second location <NUM> corresponds to an apex of a triangle, the first stiffener <NUM> and the second stiffener <NUM> correspond to first and second legs of the triangle coupled to the apex at the second location <NUM>, and the portion <NUM> of the wall <NUM> extending between the first location <NUM> and the third location <NUM> corresponds to a third leg of a triangle. Although reference is made to the plurality of stiffeners extending in a triangular arrangement, the stiffeners can be arranged in many ways to add strength to the walls of the support as described herein.

<FIG> shows holes <NUM> in a holder <NUM> of a support <NUM> of a precursor appliance <NUM> to allow fluid to drain from a precursor appliance <NUM>. The precursor appliance <NUM> may comprise an aligner <NUM> and support <NUM> as described herein. In some embodiments, the support <NUM> comprises walls as described herein. The holes <NUM> can facilitate drainage from an interior of the support as described herein, and can be helpful during cleaning and other processing of the appliance precursor <NUM>.

Although reference is made to precursor appliances comprising an appliance supported along an edge of the appliance, in some embodiments the appliance is supported on an occlusal surface of the appliance. Supporting the appliance along the occlusal surface can leave the teeth receiving cavities substantially open, so as to facilitate access to the teeth receiving cavities for removal of fluids such as residual resin and for cleaning of the appliance. In some embodiments, supporting the appliance along the occlusal surface can also eliminate the potential defects on the edge of the appliance that may occur during the removal of the supports along the edge, so as to reduce the requirement of the successive polishing process. The appliance precursor comprising supports, e.g. extensions, coupled to the occlusal surface can decrease warpage as compared with prior approaches, for example during curing of the appliance precursor.

The support may comprise extensions as described coupled to the occlusal surface to support the appliance. The extensions can be arranged in many ways to decrease the formation of printing islands, for example by supporting the occlusal surface with the extensions at local minima as described herein.

Work in relation to the present disclosure suggest that supporting the appliance along the occlusal surface can decrease the time to deposit material. In some embodiments, the appliance is oriented with respect to the direction of fabrication so as to reduce deposition time by reducing the deposition height. For example, an occlusal plane of the appliance as described herein can be oriented to within about <NUM> degrees of perpendicular to the direction of fabrication, so as to decrease an overall height of the appliance precursor.

Work in relation suggests that supporting the appliance along the occlusal surface can decrease over curing along the internal tooth receiving cavities and improve the accuracy of the shape of the internal tooth receiving cavities, which can be related to improved fitting of the appliance on teeth.

In some embodiments, supports, are coupled to the appliance to decrease warpage, such as warpage related to curing after the appliance precursor has been fabricated. In some embodiments, the supports comprise sufficient strength to decrease warpage by coupling to an exterior surface of the appliance, and the support can be configured in many ways and may comprise extensions and braces coupled to the appliance. The supports coupled to the appliance can be configured to provide regions with openings and gaps and to facilitate the removal of fluids and cleaning. In some embodiments, the appliance is coupled to the support with sufficient strength to allow manufacturing steps, such as the removal of fluid and clearing. In some embodiments, the stiffness of the supports can be appropriately configured by increasing volume of the supports, being cured separately, or with intensity curing. This approach can provide supports that are less likely to warp than the appliance and maintain the aligner in shape as designed.

<FIG> shows an appliance precursor <NUM> comprising a support <NUM> coupled to an occlusal surface <NUM> located of the appliance <NUM>. <FIG> shows the appliance precursor <NUM> of <FIG> in a different orientation. The appliance precursor <NUM> can be manufactured with the direction of deposition <NUM>, which indicates the direction in which layers of material are added to form the appliance precursor. In some embodiments, the appliance <NUM> comprises an interior surface <NUM> and an exterior surface <NUM> defining the plurality of teeth receiving cavities <NUM>.

In some embodiments, the occlusal surface <NUM> comprises a surface contour corresponding to a contour of the plurality of teeth receiving cavities. In some embodiments, the interior surface <NUM> of the appliance <NUM> is shaped to correspond to an occlusal surfaces of the tooth, and the occlusal surface <NUM> of the appliance comprises a shape corresponding to the interior surface <NUM>. This can result in the occlusal surface <NUM> of the appliance comprising structure related to the occlusal surfaces of the teeth, such as local minima as described herein.

The support <NUM> can be configured to couple to the appliance <NUM> in many ways. In some embodiments, support <NUM> comprises a holder <NUM> and a plurality of extensions <NUM> extending from the holder <NUM> to the occlusal surface <NUM>. The holder <NUM> can facilitate handling and processing of the appliance precursor <NUM>, for example while the holder retains the precursor <NUM> on the build plate or subsequent to removal from the build plate. The holder can be formed by depositing layers on a build plate of an additive manufacturing apparatus such as a 3D printer. The plurality of extensions <NUM> and appliance <NUM> can be formed with deposition of layers along the direction of deposition <NUM>.

In some embodiments, the appliance <NUM> comprises a buccal wall <NUM> and lingual wall <NUM> extending from the occlusal surface <NUM>. The buccal <NUM> wall may extend to a gingivally facing buccal edge <NUM>. The lingual wall <NUM> may extend to a gingivally facing lingual edge <NUM>. In some embodiments, the appliance <NUM> comprises a plurality of teeth receiving cavities <NUM>. In some embodiments, the buccal wall <NUM> and lingual wall <NUM> are formed with deposition of layers along the direction of deposition <NUM> so as to define the tooth receiving cavities <NUM>.

The plurality of extensions <NUM> can extend between the holder <NUM> and the occlusal surface <NUM> of the appliance, so as to provide a gap <NUM> between the holder and the occlusal surface <NUM>. The plurality of extensions <NUM> can be separated to as to provide gaps between the plurality of extensions, the holder <NUM> and the occlusal surface <NUM>, so as to define openings <NUM> between the plurality of extensions, the holder <NUM> and the occlusal surface <NUM>. These openings <NUM> can facilitate removal of material, cleaning, polishing and additional manufacturing steps.

While the plurality of extensions <NUM> can be coupled to the occlusal surface <NUM> in many ways, in some embodiments a plurality of extensions is coupled to the occlusal surface at a plurality of locations corresponding to a tooth receiving cavity, such as a single tooth receiving cavity <NUM>. The plurality of extensions <NUM> can be coupled to the occlusal surface at a plurality of locations corresponding to local minima of the occlusal surface along the direction of fabrication. Any suitable number of extensions can be coupled to the occlusal surface corresponding to a single tooth, such as one, two, three, or four extensions, and these extensions can be coupled to the occlusal surface at any suitable number of locations.

In some embodiments, the plurality of extensions <NUM> comprise weakened portions <NUM> as described herein to facilitate removal of the extensions from the occlusal surface.

In some embodiments, the direction of fabrication extends from an occlusal surface of the appliance to an interior surface of the appliance so as to decrease over curing of material along the interior surface. In some embodiments, the interior surface <NUM> may be subjected to less extensive curing than the occlusal surface <NUM>. In some embodiments, a light beam is directed to the appliance from an orientation such that the light beam can impinge directly on the interior surface <NUM> without passing through the occlusal surface <NUM> prior to impingement on the interior surface <NUM>, which can improve the accuracy of the interior surface <NUM>. In some embodiments, because a portion of the light beam illuminating the interior surface <NUM> may reach and pass through the occlusal surface <NUM>, excess material on occlusal surface can be cured while the interior surface <NUM> is cured as expected. Although reference is made to the excess curing of material on the occlusal surface, in some embodiments, the illumination to the occlusal surface can be decreased when the occlusal surface is formed, so that the total amount of illumination and curing to the occlusal surface corresponds to the intended amount after the interior surface <NUM> has been illuminated and formed.

With additive manufacturing devices such as 3D printers, a light beam can be directed to cure material such as resin to shape the appliance. The light beam can be configured to generate a layer of the appliance along a plane as described herein. Once the layer has been cured, the build plate can then move the layer away from light beam for the light beam to cure another layer of material. As the build plate moves and the light beam defines successive layer, the direction of deposition <NUM> is defined.

In some embodiments, the appliance precursor comprises side supports such as side supports coupled to the appliance near a gingivally facing portion of the appliance. In some embodiments, an array of supports such as extensions, connect to the exterior of a gingivally facing portion of the appliance. In some embodiments, the support comprises one or more walls coupled to the sidewalls of the appliance with a plurality of extensions. In some embodiments, the sidewalls of the support comprise apertures such as slots. The apertures can decrease suction force when the holder is removed from the build plate, and can allow fluids to drain from an interior of the support walls and facilitate cleaning, for example.

Work in relation to the present disclosure suggests that directly fabricated appliances may be susceptible to warping near the side walls of the appliance, and the side supports, such as extensions, as disclosed herein can be configured to decrease warpage. In some embodiments, the plurality of extensions comprises sufficient stiffness to decrease warpage related to a distance between the buccal wall and the lingual wall. In some embodiments, a first plurality of extensions is coupled to the buccal wall at a first plurality of locations and a second plurality of extensions is coupled to the lingual wall at a second plurality of locations.

<FIG> shows an appliance precursor <NUM> with side supports coupled to a one or more walls of the appliance <NUM>. The walls of the appliance <NUM> may comprise one or more of a buccal wall <NUM> or a lingual wall <NUM>. The buccal wall <NUM> may extend to a gingivally facing buccal edge <NUM>. The lingual wall <NUM> may extend to a gingivally facing lingual edge <NUM>. In some embodiments, these edges face toward the gingiva when the appliance is placed on the teeth. The side supports may comprise a plurality of extensions <NUM> extending from the holder <NUM> to the walls of the appliance. In some embodiments, the plurality of extensions <NUM> is coupled to the walls of the appliance at a plurality of locations near the gingivally facing edges, for example within about <NUM> of the gingivally facing edges of the appliance. In some embodiments, the plurality of extensions <NUM> couples to the walls of the appliance at a plurality of locations along the gingivally facing edges of the appliance, such as at a plurality of locations along the buccal edge <NUM> and a plurality of locations along the lingual edge <NUM>. The plurality of extensions <NUM> may comprise a plurality of weakened portions <NUM> to facilitate removal of the plurality of extensions from the appliance as described herein. In some embodiments a first plurality of extensions coupled to the buccal wall comprises a first plurality of weakened regions and a second plurality extensions is coupled to the lingual wall comprises a second plurality of weakened regions.

<FIG> shows an appliance precursor <NUM> with side supports coupled to a wall <NUM> of the appliance and apertures <NUM>. In some embodiments, the wall <NUM> is thickened to prevent the appliance <NUM> from warping under cleaning conditions, such as extreme cleaning conditions. The wall can be topologically optimized to reduce material consumption while maintaining stiffness. The apertures <NUM> can be configured to reduce suction force when the precursor is separated from a build plate, or to drain fluid from the wall <NUM> and facilitate cleaning, for example. In some embodiments, the support <NUM> comprises holder <NUM>, wall <NUM>, and plurality of extensions <NUM> coupled to the appliance <NUM>. In some embodiments the plurality of extensions <NUM> extend from the wall <NUM> to the one or more of the buccal wall <NUM> or the lingual wall <NUM> of the appliance <NUM>.

In some embodiments, the wall <NUM> of the support <NUM> comprises a buccal wall <NUM> coupled to the buccal wall <NUM> of the appliance <NUM>. In some embodiments, the plurality of extensions <NUM> couples to the buccal wall <NUM> at a plurality of locations near the edge <NUM> of the buccal wall, for example within <NUM> of the edge or along the edge as described herein.

In some embodiments, the wall <NUM> of the support <NUM> comprises a lingual wall <NUM> coupled to the lingual wall <NUM> of the appliance <NUM>. In some embodiments, the plurality of extensions <NUM> couples to the lingual wall <NUM> at a plurality of locations near the edge <NUM> of the lingual wall, for example within <NUM> of the edge or along the edge as described herein. In some embodiments, a gap extends between the wall of the support and the one or more of the buccal wall or the lingual wall of the appliance and wherein the plurality of extensions extends across the gap. In some embodiments, the gap comprises a gap <NUM> extending between the buccal wall <NUM> of the support <NUM> and the buccal wall <NUM> of the appliance. In some embodiments, the gap comprises a gap <NUM> extending between the lingual wall <NUM> of the support <NUM> and the lingual wall <NUM> of the appliance.

The plurality of extensions <NUM> may comprise a plurality of weakened portions <NUM> as described herein to facilitate removal of the appliance from the extensions. In some embodiments a first plurality of extensions coupled to the buccal wall comprises a first plurality of weakened regions and a second plurality extensions is coupled to the lingual wall comprises a second plurality of weakened regions.

<FIG> shows an appliance precursor <NUM> with side supports coupled to a wall of an appliance, in which the appliance support comprises a side wall <NUM> and the side supports extend between the wall of appliance and the wall of the support. In some embodiments, the wall <NUM> is thickened to prevent the appliance <NUM> from warping under cleaning conditions, such as extreme cleaning conditions. The wall can be topologically optimized to reduce material consumption while maintaining the stiffness. The appliance precursor <NUM> shown in <FIG> comprises structures similar to the structures described with reference to <FIG>.

The wall <NUM> of the support <NUM> may comprise an interior extending between the buccal wall <NUM> and the lingual wall <NUM>. The interior of the wall <NUM> can be configured in many ways, and may comprises internal stiffeners as described herein.

Referring again to <FIG>, in some embodiments, a first plurality of extensions <NUM> is coupled to the sides of the appliance along with a second plurality of extensions <NUM> coupled to the occlusal surface of the appliance with openings and gaps as described herein, for example with reference to <FIG>.

Alternative or additional support structures can be coupled to the appliance to decrease warpage of the appliance. In some embodiments, a cage is coupled to the appliance to decrease warpage.

<FIG> shows an appliance precursor <NUM> with a cage <NUM> extending around a portion of the appliance to support walls of the appliance. <FIG> shows a cross-sectional view of an appliance precursor comprising a cage as in <FIG>. <FIG> shows a cross-sectional end view of the appliance precursor comprising a cages as in <FIG>.

In some embodiments, the cage comprises a band <NUM> and a plurality of extensions <NUM>. The band extends at least partially around a portion of the appliance <NUM>. The plurality of extensions <NUM> extends from the band <NUM> to the to the appliance <NUM> to couple to the appliance at a plurality of locations. The plurality of extensions <NUM> can be configured to couple to the appliance at any suitable location. In some embodiments, the extensions <NUM> couple to a portion <NUM> of the appliance around which the cage extends. In some embodiments, the band <NUM> extends completely around the portion of the appliance, e.g. <NUM> degrees, and the portion <NUM> of the appliance extends through the band. In some embodiments, the plurality of extensions extends to the portion <NUM> of the appliance extending through the band. The band <NUM> can be configured in many ways, and may generally comprises a support structure extending at least partially around the appliance <NUM>.

The band <NUM> may comprise any suitable cross-sectional thickness, cross sectional width, and strength. In some embodiments, the band comprises a perimeter corresponding to one or more of a C-shape, an oblong shape, an oval shape, triangle, a polygon, a rectangle, or a square.

In some embodiments, the plurality of extensions <NUM> couples to the walls of the appliance near one or more gingivally facing edges of the appliance as decreased herein. The extensions <NUM> may comprise one or more regions comprising weakened portions as described herein.

<FIG> shows an appliance precursor <NUM> comprising a cage <NUM> coupled to an appliance <NUM> around a plurality of sections of the appliance corresponding to opposite sides of a mouth of a patient. In some embodiments, the band <NUM> extends around both of the sections corresponding to opposite sides of the mouth. A first plurality of extensions <NUM> extends from band <NUM> to a first portion of the appliance corresponding to a first side of the mouth, and a second plurality of extensions <NUM> extends from the band <NUM> to a second portion of the appliance corresponding to a second side of the mouth.

<FIG> shows a cross-sectional view of an appliance precursor <NUM> comprising cage <NUM> extending around a portion of an appliance <NUM> and coupling to an interior of the appliance with a plurality of extensions <NUM>. In some embodiments, the plurality of extensions couples to the appliance along an interior of the appliance. The interior of the appliance <NUM> comprises a tooth facing surface of the appliance as described herein. The structure extending to the interior of the appliance can improve handling of the appliance for additional manufacturing steps.

In some embodiments, the plurality of extensions <NUM> is coupled to local minima on the interior of the appliance, for example when the appliance is support on one or more edges as described herein.

The cage <NUM> can be configured to facilitate removal from the appliance. The band <NUM> of the cage <NUM> can be located a sufficient distance from the appliance to serve as a handle or grasping structure to remove the band. The plurality of extensions <NUM> may comprise regions with weakened portions as described herein to facilitate removal.

The embodiments of <FIG> may comprise one or more of the features described with respect to 23A to 23B, and description of like elements with like reference numbers has not be repeated.

The cages <NUM> described with reference to <FIG> are well suited for use with different directions of deposition and orientations, for example with reference to edge supported embodiments as disclosed herein.

<FIG> shows an appliance precursor <NUM> comprising a brace <NUM> extending from a holder <NUM> to a wall of an appliance <NUM> near a gingivally facing edge of the appliance. The gingivally facing edge may comprise a buccal edge <NUM> or a lingual edge <NUM>, for example. The brace <NUM> can be coupled to near the edge, for example within <NUM> of the edge, or along the edge as described herein. The brace <NUM> may comprise first extension <NUM> coupled to the holder <NUM> and a second extension <NUM> coupled to the appliance wall near the edge. In some embodiments, the first extension <NUM> extends away from the appliance wall and the second extension <NUM> extends away from the holder to define a handle shaped portion to facilitate remove of the brace <NUM>. In some embodiments, the first extension <NUM> comprises weakened portion as described herein to facilitate removal from the holder <NUM> and the second portion <NUM> comprises a weakened portion as described herein to facilitate removal of the brace from the appliance.

<FIG> shows an appliance precursor <NUM> comprising a brace <NUM> extending between a buccal wall <NUM> of an appliance and a lingual wall <NUM> of the appliance. In some embodiments, the brace <NUM> is coupled to the buccal wall <NUM> near a gingivally facing buccal edge <NUM> and to a lingual wall <NUM> near a buccal edge <NUM>, for example within <NUM> of each of the edges or along each of the edges.

<FIG> shows an appliance precursor <NUM> comprising a brace <NUM> extending between a buccal wall <NUM> of an appliance <NUM> and a lingual wall <NUM> of the appliance with a portion of the brace extending away from the edges of the appliance to facilitate removal. In some embodiments a first extension <NUM> is coupled to the lingual wall and a second extension <NUM> is coupled to the lingual wall, and the first extension and the second extension are inclined relative to each other to a so define a handle portion to facilitate removal.

The first extension <NUM> may comprise a weakened portion near first edge of a first wall as described herein and the second portion <NUM> may comprise a weakened portion near a second edge of a second wall as described herein to facilitate removal.

The embodiments of <FIG> may comprise one or more of the features described with respect to 23A to 23B.

Although the brace <NUM> has been described with reference to an appliance <NUM> supported on an occlusal surface, the brace <NUM> can be used with other embodiments, for example with edge supported appliances with different fabrication directions as described herein.

<FIG> shows an appliance precursor <NUM> comprising an appliance <NUM> with an appliance stiffener <NUM>. The appliance stiffener <NUM> can be configured in many ways. In some embodiments, the appliance stiffener extends along a wall of the appliance adjacent a plurality of teeth receiving cavities so as to add stiffness for movement of the teeth received in the plurality of cavities. In some embodiments, the stiffener comprises a region of increased thickness on the appliance as compared with other regions of the appliances, so as to apply increased forces to one or more teeth. In some embodiments, the stiffener comprises an integrally formed component of the appliance. For example, the stiffener may comprise a plurality of deposition layers as described herein, in which the plurality of deposition layers extends from the stiffener to an interior surface of the appliance comprising the plurality of teeth receiving cavities.

The stiffener <NUM> can be added to the appliance <NUM> for stiffening the appliance. In addition to holding the shape under various manufacturing process, the stiffener <NUM> may help increase orthodontic forces to move teeth. The stiffener <NUM> may comprise a portion of the appliance placed on the patient's teeth.

<FIG> shows a method <NUM> of manufacturing an appliance.

At a step <NUM>, an orientation of an appliance in relation to a direction of deposition of an additive manufacturing machine is determined. The orientation of the appliance may comprise any orientation disclosed herein. The direction of deposition may comprise any orientation of the direction of deposition as disclosed herein.

At a step <NUM> a support comprising a plurality of extensions coupled to the appliance is defined. The plurality of extensions may comprise any of the extensions disclosed herein.

At a step <NUM>, the plurality of extensions is defined to couple to one or more walls of the appliance. The appliance may comprise any appliance as disclosed herein, and the plurality of locations may comprise any locations as disclosed herein.

At a step <NUM>, a plurality of coupling locations near one or more gingivally facing edges of the appliance is defined. The plurality of coupling locations may comprise any coupling locations as disclosed herein.

At a step <NUM>, a plurality of weakened regions of the plurality of extension is defined at a plurality of locations where the plurality of extensions couple to the appliance. The plurality of weakened regions may comprise any weakened region or weakened portion as disclosed herein.

At a step <NUM>, a separation distance between the appliance and a holder is defined so as to define a gap between the appliance and the holder. The separation distance and gap may comprise any distance and gap as disclosed herein.

At a step <NUM>, a plurality of separation distances between the plurality of extensions is defined so as to provide a plurality of gaps extending between the plurality of separation distances. The plurality of distances and the gaps may comprise any separation distances and gaps as disclosed herein.

At a step <NUM>, a profile of a wall is defined to couple the appliance to a holder. The wall may comprise any wall as disclosed herein.

At a step <NUM>, a plurality of internal stiffeners is defined so as to couple to the wall. The internal stiffeners may comprise any stiffeners as disclosed herein.

At a step <NUM>, the plurality of extensions is defined so as to extend between the wall and the appliance with a gap between the appliance and the wall, the plurality of extensions extending across the gap. The extensions, the appliance, the gap and the wall may comprise any combination of those disclosed herein.

At a step, <NUM>, a cage is defined to couple to the appliance with a plurality of extensions. The cage may comprise any cage as disclosed herein, such as cage <NUM>, and the extensions, locations and arrangements may comprise any of those disclosed herein.

At a step <NUM>, a brace is defined so as to couple to the appliance. The brace may comprise any brace as disclosed herein, such as brace <NUM>, and any structure of the brace can be defined.

At a step <NUM>, a stiffener of the appliance is defined to add strength to the appliance. The stiffener may comprise any stiffener as disclosed herein, such as stiffener <NUM>.

At a step <NUM>, a plurality of local minima of the appliance along the direction of fabrication are defined. The plurality of local minima may comprise any of the local minima as disclosed herein.

At a step <NUM>, a plurality of locations of the plurality of extensions is defined to support the plurality of local minima along the direction of fabrication. The plurality of locations and extensions may comprise any locations and extensions and related structures as disclosed herein.

As a step <NUM>, a plurality of deposition layers is deposited along the direction of deposition. The layers may comprise any layers disclosed herein.

The method <NUM> is a method of manufacturing an appliance in accordance with some embodiments. A person of ordinary skill in the art will recognize many adaptations and variations. The steps can be performed in any order. Some of the steps can be repeated and some of the steps can be omitted. Additional steps can be added or combined with steps of any method disclosed herein. Also, additional steps can be implemented, such as cleaning the appliance, decoupling the appliance from the support, and polishing the appliance as described herein.

While the steps of the method <NUM> can be performed in many ways, in some embodiments, one or more of the steps are performed with a processor comprising instructions configured to perform the one or more steps, for example as described herein with reference to <FIG>.

The inventors have conducted experiments in accordance with the present disclosure and have produced appliances coupled to supports and extensions as described herein. The inventors have taken optical images of the precursor showing the appliance and extensions and deposition layers as described herein.

<FIG> illustrates an example of a precursor to a dental appliance manufactured according to the described embodiments. Dental appliance precursor <NUM> comprises a dental appliance <NUM>, support <NUM>, and a holder <NUM>. Ellipse <NUM> identifies a portion of the dental appliance precursor <NUM> where the support <NUM> transitions to dental appliance <NUM>.

<FIG> is a close-up view of the portion of the dental appliance precursor <NUM> identified by ellipse <NUM> in <FIG>, which shows the structures describe with reference to <FIG>. The dental appliance precursor <NUM> comprises a plurality of layers that are visible as striations in the part. The first plurality of layers <NUM> corresponds to the extension <NUM> of the support <NUM>, the second plurality of layers <NUM> corresponds to a combination of the extension <NUM> and the first and second portions of the dental appliance <NUM>. The third plurality of layers <NUM> corresponds to the third portion of dental appliance <NUM>, which couples the first portion to the second portion of the appliance. The removal line <NUM> is formed between the transition from the support <NUM> to the dental appliance <NUM>. The dental appliance precursor <NUM> may be separated at the removal line to obtain the dental appliance <NUM> as described herein.

As detailed above, the computing devices and systems described and/or illustrated herein broadly represent any type or form of computing device or system capable of executing computer-readable instructions, such as those contained within the modules described herein. In their most basic configuration, these computing device(s) may each comprise at least one memory device and at least one physical processor.

The term "memory" or "memory device," as used herein, generally represents any type or form of volatile or non-volatile storage device or medium capable of storing data and/or computer-readable instructions. In one example, a memory device may store, load, and/or maintain one or more of the modules described herein. Examples of memory devices comprise, without limitation, Random Access Memory (RAM), Read Only Memory (ROM), flash memory, Hard Disk Drives (HDDs), Solid-State Drives (SSDs), optical disk drives, caches, variations, or combinations of one or more of the same, or any other suitable storage memory.

In addition, the term "processor" or "physical processor," as used herein, generally refers to any type or form of hardware-implemented processing unit capable of interpreting and/or executing computer-readable instructions. In one example, a physical processor may access and/or modify one or more modules stored in the above-described memory device. Examples of physical processors comprise, without limitation, microprocessors, microcontrollers, Central Processing Units (CPUs), Field-Programmable Gate Arrays (FPGAs) that implement softcore processors, Application-Specific Integrated Circuits (ASICs), portions of one or more of the same, variations or combinations of one or more of the same, or any other suitable physical processor.

Although illustrated as separate elements, the method steps described and/or illustrated herein may represent portions of a single application. In addition, in some embodiments one or more of these steps may represent or correspond to one or more software applications or programs that, when executed by a computing device, may cause the computing device to perform one or more tasks, such as the method step.

In addition, one or more of the devices described herein may transform data, physical devices, and/or representations of physical devices from one form to another. For example, one or more of the devices recited herein may receive image data of a sample to be transformed, transform the image data, output a result of the transformation to determine a 3D process, use the result of the transformation to perform the 3D process, and store the result of the transformation to produce an output image of the sample. Additionally or alternatively, one or more of the modules recited herein may transform a processor, volatile memory, non-volatile memory, and/or any other portion of a physical computing device from one form of computing device to another form of computing device by executing on the computing device, storing data on the computing device, and/or otherwise interacting with the computing device.

The term "computer-readable medium," as used herein, generally refers to any form of device, carrier, or medium capable of storing or carrying computer-readable instructions. Examples of computer-readable media comprise, without limitation, transmission-type media, such as carrier waves, and non-transitory-type media, such as magnetic-storage media (e.g., hard disk drives, tape drives, and floppy disks), optical-storage media (e.g., Compact Disks (CDs), Digital Video Disks (DVDs), and BLU-RAY disks), electronic-storage media (e.g., solid-state drives and flash media), and other distribution systems.

A person of ordinary skill in the art will recognize that any process or method disclosed herein can be modified in many ways. The process parameters and sequence of the steps described and/or illustrated herein are given by way of example only and can be varied as desired.

The various exemplary methods described and/or illustrated herein may also omit one or more of the steps described or illustrated herein or comprise additional steps in addition to those disclosed. Further, a step of any method as disclosed herein can be combined with any one or more steps of any other method as disclosed herein.

Unless otherwise noted, the terms "connected to" and "coupled to" (and their derivatives), as used in the specification and claims, are to be construed as permitting both direct and indirect (i.e., via other elements or components) connection. In addition, the terms "a" or "an," as used in the specification and claims, are to be construed as meaning "at least one of. " Finally, for ease of use, the terms "including" and "having" (and their derivatives), as used in the specification and claims, are interchangeable with and shall have the same meaning as the word "comprising".

The processor as disclosed herein can be configured with instructions to perform any one or more steps of any method as disclosed herein.

As used herein, the term "or" is used inclusively to refer items in the alternative and in combination.

As used herein, the term "and/or" is used inclusively to refer items in the alternative and in combination.

It will be understood that although the terms "first," "second," "third", etc. may be used herein to describe various layers, elements, components, regions or sections without referring to any particular order or sequence of events. These terms are merely used to distinguish one layer, element, component, region or section from another layer, element, component, region or section. A first layer, element, component, region or section as described herein could be referred to as a second layer, element, component, region or section without departing from the teachings of the present disclosure.

Claim 1:
A dental appliance precursor (<NUM>), comprising:
a dental appliance (<NUM>) comprising a plurality of teeth receiving cavities (<NUM>), the appliance comprising a buccal wall and a lingual wall to at least partially define the plurality of teeth receiving cavities; and
a support (<NUM>) comprising a plurality of extensions (<NUM>) coupled to the dental appliance, the support comprising a holder to couple to an additive manufacturing machine, the support extending between the holder and the appliance;
wherein the dental appliance comprises an occlusal plane (<NUM>) and is formed from a plurality of deposition layers of material oriented at an angle between <NUM> and <NUM> degrees with respect to the occlusal plane.