Patent for “Three-dimensional, printed dental appliances with support structures”

3D Printing – Huafeng Wen, Ulab Systems Inc

Search Patent for “Three-dimensional, printed dental appliances with support structures”

Abstract for “Three-dimensional, printed dental appliances with support structures”

“Systems and methods for fabricating an oral or dental appliance using support structures are disclosed. The patient’s dentition may be captured in three dimensions and reconfigured to correct one or more malformations. An inner structure may be used to support the oral appliance while it is being printed. After the oral appliance has been completed, the inner structure can be removed.

Background for “Three-dimensional, printed dental appliances with support structures”

Orthodontics is a speciality in dentistry that deals with malocclusion. This can occur as a result of tooth irregularity or a disproportionate facial relationship. Orthodontics deals with malocclusion by removing teeth through bony remodeling, and controlling and modifying facial growth.

This process was traditionally achieved by using static mechanical force to induce bone remodeling and thereby allow teeth to move. Braces are made up of an archwire interface and brackets attached to each tooth. The wires are tightened again to add pressure to the teeth as they respond to pressure via the archwire. This well-known method of treating malocclusion takes approximately twenty-four months to complete. It can be used to treat many different types of malocclusion. Braces can be painful and uncomfortable for patients. Orthodontic appliances can also be perceived as not being aesthetically pleasing, which creates resistance to treatment. The treatment time cannot be reduced by increasing the force. Too high a force can cause root resorption and make it more painful. This makes the average treatment time 24 months long and reduces the amount of usage. According to some estimates, less than half the patients who would benefit from orthodontics will choose to go for it.

The tooth positioning appliance was introduced by Kesling in 1945 to refine the final stage of orthodontic finishing following the removal of braces (debanding). The positioner was a single-piece, pliable rubber appliance made on the idealized wax set ups for patients who had completed their basic treatment. Kesling predicted that certain major movements of the teeth could be achieved with a series positioners, which were fabricated using sequential movements of the set-up. This idea was not practicalized until 3D scanning and computer. It was used by Align Technologies, ClearAligner, ClearCorrect, and other companies such as OrthoClear and ClearCorrect to improve aesthetics.

“In one aspect, methods and systems are disclosed that allow for the fabrication of one or more oral appliances. This is done by creating a three-dimensional representation of a subject’s body such as the dentition and then creating an inner support structure. One or more oral appliances can be built directly on one or more support structures. After the dental appliance is complete, the inner support structure can be removed. This will allow the appliance to fit over one or more of the teeth and correct malocclusions.

One method of fabricating an oral appliance is to capture a three-dimensional representation of a subject’s dentition. Then, you can fabricate a support structure that corresponds to the outer surface of the subject’s dentition. Next, you will form one or several oral appliances on the exterior surface of this support structure so that the interior conforms to the dentition. Finally, you will remove the support structure from the interior.

The one or more appliances can be arranged in a way that corrects malocclusions. The support structure can be made from one material, and the oral appliances from another material.

“The oral appliance assembly generally consists of a support structure with an exterior surface that corresponds to an outside surface of a subject’s dentition. The oral appliance is formed upon the exterior of the support structural via three-dimensional printing so that the interior of the formed appliance conforms to the subject’s dentition. In this case, the second material is used to fabricate the oral device.

The support structure can be removed from the inside of the made oral appliance so that it is easily positioned upon the dentition. A plurality of oral appliances can be made where each appliance is designed to move one or several teeth to correct malocclusions. Each oral appliance can be built upon a number of support structures.

The structures of the invention can have different stiffnesses in different parts and can be transparent even though they were made at least partially by additive manufacturing. The free-form structures of the invention can be constructed as one piece and may include internal or external sensors.

“The present invention will only be described in relation to certain embodiments, but it is not limited by the claims. The claims do not limit the scope of the invention.

“The singular forms?a,?an, and??the are used herein. If the context requires otherwise, both singular and plural referents are included.

“The terms ‘comprising? and?comprises are interchangeable. “Comprising?,?comprises?” and?comprised? are synonyms. As used herein, the terms?comprised of? and?including? are synonyms with?includes? as used herein are synonymous with?includes?,??includes?. The terms ‘comprising’,?comprises? are not interchangeable. ?comprised? and?comprising? are synonyms for?comprising?,?comprises? When referring to recited elements, members or method steps, embodiments that?consists of? are also included. “Recited members, elements, or method steps”

“Furthermore the terms first, second and third in the description and in claims are used to distinguish between similar elements. They are not necessary for describing a chronological or sequential order unless otherwise specified. The terms used herein can be interchanged in the appropriate circumstances. Furthermore, the embodiments described herein can operate in different sequences than those described or illustrated.

“The term ‘about’ is defined as: “The term?about? is used herein to refer to a measurable value like a parameter or an amount or a temporal duration. It can include variations of +/-10% or lower, more preferably?1% or lower, and even more preferably?0.1% or fewer of the specified value, as long as such variations are necessary to perform the disclosed invention. The value to which the modifier “about” refers is to be understood. It is to be understood that the value to which the modifier?about? refers is also explicitly, and preferably disclosed.”

“The recitation by endpoints of numerical ranges includes all numbers or fractions that are included within those ranges as well as the endpoints.”

“All documents cited within the present specification are herein incorporated by reference in full.”

“Unless otherwise specified, all terms used to disclose the invention, including scientific terms, have the same meaning as one with ordinary skill in art to which it belongs. To help you better understand the teachings of the invention, we have included definitions of terms used in this description. These definitions and terms are only intended to help you understand the invention.

“Refer throughout this specification only to?one embodiment?” or ?an embodiment? It means that at least one embodiment contains a particular feature, structure, or characteristic related to the embodiment. The phrases “in one embodiment” and “in another embodiment” are examples of this. Or?in one embodiment? The various references in this specification do not always refer to the same embodiment. The particular features, structures, and characteristics can be combined in any way that is most appropriate, as would be obvious to someone skilled in the art. This could be done in one or more embodiments. While some embodiments may include certain features that are not included in other embodiments of the invention, combinations of features from different embodiments are allowed within the scope and can create different embodiments. In the following claims, for example, any of these embodiments may be combined.

For example, when fabricating dental appliances like aligners or retainers using 3D printing processes, hollow shapes can be created with complex geometries by using tiny cells called lattice structures. Topology optimization is a technique that allows for the efficient mixing of solid-lattice structures and smooth transitional material volumes. The lattice’s performance can be analyzed under tension, compression and shear as well as flexion, torsion and fatigue life.

An intermediate structure may be required to support the 3D printed oral appliance. This is due to the complexity of the resulting shapes. These intermediate structures can be temporarily used and may then be removed, separated or disengaged from an oral appliance being made.

“FIG. “FIG. The dental appliance 10 is intended to be worn for no more than 18 hours per day and last approximately one month. The shell of the dental device 10 is durable and typically has a thickness of 0.5mm. The structure shown in FIG. allows you to 3D-print such a shell or dental part for covering teeth or teeth. The inner support structure 14 may be used to support the appliance 10, which is supported by the support structure 14. The complex anatomy of the oral device 10’s occlusal surfaces 12 may require a mirroring surface 16 from the support structure 14. This will allow the oral appliance to be supported adequately by the interfacing 16 created during manufacturing.

The support structure 14 can be easily removed from the opening 18 of the appliance 10, once the appliance 10 is formed. In one embodiment, the support structure 14 may have a width similar to that of the appliance 10, to permit the removal of the support 14. The appliance 10 can be made from any number of different polymers. For example, silicone, polyurethane and polyepoxide as well as polyamides or blends thereof. The support structure 14 may also be made from the same material, but different from the appliance 10. The support structure 14 may be made from a different material than that of the appliance 10. This will allow for the easy separation and removal from the appliance 10.

“Aside from the support structure 14 being placed directly below the appliance 10, other embodiments may include support structures formed in one or more layers as shown in FIGS. 2A and 2B. FIG. FIG. 2A illustrates one embodiment of an oral device 20 in fabrication. An inner core layer 22 can be formed (e.g. via 3D printing of a first material configured to follow the contours and shape of the dentition). After the inner layer 22 has been fabricated, an inner layer 24 can be printed on the interior surface of the inner layer 22 while an outer layer 26 may be printed on the exterior surface. To allow the fabrication of the inner-appliance layer 24, the inner core layer 22 can be slightly larger than the dentition. To form the desired oral appliance 20, the inner appliance layer 24 may be printed on the outer appliance layer 26 either in a sequential or simultaneous fashion. The inner core layer 22 can be removed, washed or otherwise dissolved. This will leave the finished oral appliance 20 with the inner appliance layer 24 intact and the outer appliance layer 26 intact.

FIG. FIG. 2B is a side-view of a cross sectional arrangement in which the oral appliance 28 can be manufactured by an appliance layer 30 that is sandwiched between an outer core layer 34 and an inner core layer 32. To allow the fabrication of the appliance layer 30, the inner core layer 32 can be slightly smaller than the dentition. After the appliance layer 30 is fabricated, supported by the outer core layer 32 & 34, the outer core layer 34 and inner core layer 32 may be removed. The appliance layer 30 can then be dissolved.

“In another embodiment, the appliance can be made with projections, protrusions or other features to provide additional flexibility when treating patients. FIG. FIG. 3 shows a cross sectional side view showing an example of a printed dental appliance 40 that has a cavity or pocket 42 along one side of the device. This cavity or pocket can be used to receive an attachment, such as an elastic, which can be placed on the cavity or pocket 42. As shown, the support structure may include a projection 44 that causes the 42-corresponding pockets or cavities to protrude from oral appliance 40. To provide more treatment options and enhance the effectiveness of the oral device, certain features can be 3D printed. Other embodiments may not require any extra features, but the feature 44 or projection 44 can be attached or secured to certain regions of the support framework for creating the cavity or pocket 42 on the oral appliance 40. Optionally, the projection or feature may be designed to allow non-isotropic friction in a single direction. This allows the device to grab teeth more effectively and move to its intended position.

“In another embodiment, features and projections can be integrated into the oral appliance to provide additional forces or facilitate tooth movement. FIG. 4 shows one example. 4. This shows a projection 50, which is a metallic or polymeric ball, that is positioned by an oral device (not shown for clarity) between two adjacent teeth 56, 54. The oral appliance may include a projection 50 that extends from it and touches a specific region of a tooth or teeth. This is to allow for separation between adjacent teeth 56, 54. Although only 50 projections are shown, multiple projections can be used in the oral appliance.

“Aside form projections, the oral device 60 may also include channels, grooves or features that allow for the addition of other devices. FIG. 1 shows an exemplary oral device 60. FIG. 5 is positioned on the teeth 62 and has slots 64,66 within the oral device 60 to receive the supporting wires. You can configure the oral appliance 60 to accept wires, hooks and rubber bands. This is to augment the corrective forces provided by the oral appliance 60. It may also be printed with slots 64,66. For illustration purposes, the wire 68 is shown anchored within slots 64 and 66 of oral appliance 60. However, other slot positions or incorporating additional features or elements can be made.

“Another embodiment allows the shell of an oral appliance to be extended or thickened without causing any harm to patients. This is possible due to precise gingival modeling. These extended areas can help strengthen the shell (e.g. plastic), especially when a shorter plastic shell is not able to provide the required strength.

“FIG. “FIG. 6” shows an example of how to adjust the thickness of the 3D-printed oral appliance. After scanning the subject’s teeth and electronically converting them, the upper and the lower arch models 70 can be loaded into the memory system of a computer with a programmable processor. The digital model can be mounted to a virtual articulator 72 after the bite registration has been set. A program may be used to create an initial shell model with a predetermined thickness of 74. The thicker portions of the oral appliances provide a stronger area. In FIG. 5, the practitioner can include projections 50. 4. The practitioner can also incorporate features such as the projections 50 in FIG. To calculate overlap between upper and lower arch shells 78, the system can be programmed to activate an articulator. The shell model of an oral appliance can also be affected by the resulting stresses.

The system can then trim any excess shell material 80 from the model. Any isolated islands or peninsulars may also be removed 82. The 3D model can then be exported to a 3D printing machine 84 for fabrication of the dental shell or appliance.

“FIG. “FIG. 7” shows an alternative method to determine the thickness of an oral appliance using physical simulations. The digital models of the lower and upper archs can be loaded into the memory of a computer, similar to the previous process. The system may then calculate the movements that will occur for each tooth 92. The system can then create an analytic model of the initial shell shape. 94 To optimize shell shapes, the system may run an analysis model that includes thicknesses and any ancillary parts or components that may be required or desired. The 3D model can be optimized to ensure patient comfort and reduce resin costs 98. The result can then be sent to a 3D printer 100 for fabrication of the shell or oral appliance.

“Conventional oral appliances are generally made from pressure-formed plastic shells. The plastic shell should be thinner (e.g. thinner than the rest of the appliance) in the areas that touch the occlusal regions of the patient?s dentition. This ensures that the patient’s bite remains unaffected during treatment. The embrasure, or the side surfaces, should be thicker so that the teeth or malocclusions can be pushed to their designated locations. These embrasure areas are often stretched thinner during the process of making the oral appliance. The system described herein can be used to determine which areas of the oral appliance affect the bite. It may also allow the appliance to be made thinner in certain areas, or even remove material entirely to create a hole.

“Free-form lattice systems that fit at least a portion of the surface (e.g. The oral appliance may be made by using an external contour of a body part. The described embodiments may use free-form lattices to form or fabricate appliances that are intended for placement on the exterior surfaces of the patient’s dentition. A basic structure of a lattice is used to create the free-form structure. The lattice may contribute to a free form structure with a defined rigidity. A coating material may also be applied to the lattice. The coating material is used to cover, impregnate, or surround the lattice structure. The structure’s transparency can also be enhanced by lattice structures.

“Free-form lattice structures” is a term that refers to any structure with an irregular or asymmetrical flowing contour or shape, which more specifically fits at least part of a body’s contour. In certain embodiments, the free form structure could also be called a free-form top. A free-form structure is a two-dimensional form contained within a three-dimensional space. As described herein, this surface is essentially two-dimensional because it has a limited thickness but can still have a variable thickness. It is a lattice structure that has been rigidly set to imitate a particular shape. This creates a three-dimensional structure.

“Free-form structures or surfaces are typically distinguished by the absence of corresponding radial dimension, which is unlike regular surfaces like planes, conic and cylinders. The skilled person is familiar with free-form surfaces and they are widely used in engineering design disciplines. The surface forms are typically described using non-uniform rational (NURBS), mathematics. However, other methods like Gorden surfaces and Coons surfaces can be used. The free-form surface form is not defined in terms of polynomial formulas but rather by the poles, degree and number of patches (segments containing spline curves). Triangulated surfaces are also possible. In this case, triangles are used as a way to approximate 3D surfaces. Triangulated surfaces can be found in Standard Triangulation Language files (STL), which are well-known to anyone skilled in CAD design. Because of the presence of rigid basic structures, the free-form structures can be adapted to the surface of any body part. This gives the structures their free-form characteristics.

“The term “rigid” is used to describe a structure that is rigid. “The term “rigid” refers to the lattice and/or free form structures that they comprise. Particular embodiments of the structure are not foldable on themselves without compromising its mechanical integrity, whether it is manually or mechanically. The structure and/or the material of the lattice structures can affect the stiffness of the structures, despite the rigidity of their overall shape. It is possible that free-form and lattice structures may allow for some flexibility in handling, even though they maintain their three-dimensional shape. The nature of the lattice pattern, the thickness and the nature the material can all lead to local variations. If the free-form structures described herein are made up of separate components (e.g. Non-continuous lattices are interconnected by hinges or areas of coating material, so the rigidity of the form may be restricted to the individual parts of a lattice.

U.S. Prov. may provide more detail on the fabrication of dental appliances. App. App.

“Generally speaking, the fabrication process involves designing an appliance that will be worn on the teeth, creating the mold and providing the (one- or more) lattice structure within. Then, providing the coating material in mold to form the freeform structure. Free-form structures can be customized for each patient. They are designed to fit the anatomy and dentition of specific patients, such as animals or humans. The 3D representation of surfaces (e.g., teeth, gums, etc.) is essential for the fabrication of an oral appliance. A 3D scanner can capture the external contours of a patient’s dental work to correct one or more malocclusions. A handheld laser scanner can capture the external contours of a patient’s dentition to correct one or more malocclusions. The data can be used to create a digital, 3-dimensional model of the subject. A technician or a medical practitioner can also scan the subject or part of the subject to provide the patient-specific images. These images can be converted to a three-dimensional representation or part thereof. You may also be able to manipulate the image and clean it up.

“FIG. 8A is a perspective view showing an exemplary oral appliance 120 with two parts 122 (for upper and lower dentitions). The final oral appliance can include a lattice structure (124), which is typically included in the oral appliance 120. The lattice 124 may be 3D printed to create an approximate shape of the final oral appliance. Next, place the dental appliance 126 and 126. The dental appliance 126, 126 may then be filled with the impregnating materials 128, e.g. polymer or any other material described herein. The dental appliance is divided into 126 and 126 after the impregnating material 128 has been set. are removed to reveal the coated oral appliance 120

“While the whole lattice 124 can be impregnated with the impregnating substance 128, certain portions may not be coated. Other surfaces may remain exposed. These embodiments may be modified to suit the oral appliance 120 as shown in FIG. 8A.”

As can be seen, a 3D-printed progressive aligner of increasing and/or decreasing thickness offers certain advantages. The rate of the incremental increase in thickness is not dependent on the standard thicknesses available as an industrial commodity. A 3D printing process could establish an optimal thickness. Instead of being restricted to the e.g. 0.040, 0.0.060, and 0.080 inches, 3D printing could be extended to include a thickness that is optimal. An orthodontist might choose a thickness sequence like 0.040 to 0.053 to 0.066 in. thickness is for an adult patient, whose teeth are more likely to move slowly than those of a rapidly growing teenager.

An aligner made from thinner material will produce lower corrective forces than one made from the same material. Therefore, an aligner could be printed 3D to be thicker where more forces are required and thinner where less is needed. To help practitioners with many of the most difficult daily challenges, it could be a good idea to have aligners that are both a default thickness and adjustable in thickness. Malocclusions will include teeth that are farther from their final positions than others. Some teeth are smaller than others, and the size of a tooth is related to the absolute force threshold that must be met to cause tooth movement. Some teeth can seem more stubborn than others due to factors such as the distance between the root and the boundaries between the cortical bony support and the alveolar bony support. Other teeth can be more difficult to rotate, angulate or straighten than others. Other teeth or groups of teeth might need to be moved bodily as quickly as possible over relatively large distances in order to close open spaces. You have the option to adjust aligner thicknesses and force levels for areas with larger or more difficult teeth. This allows you to give your selected teeth greater forces than small, almost ideal-positioned teeth.

“The free-form, lattice structure used in dental appliances can at least partially be manufactured by additive manufacturing (AM). In particular, the basic structure can be made by additive manufacturing using the lattice. A group of techniques that can be used to create a tangible model of an object using 3D computer-aided design (CAD), data typically associated with the object. There are many AM techniques that can be used, including stereolithography and selective laser sintering. Selective laser sintering is a technique that uses a laser beam or other focused heat source to melt or sinter small pieces of metal, plastic, or ceramic powders to form a mass. Fused deposition modeling, and other related techniques use a temporary transition between a solid material and a liquid state. This is usually caused by heating. The material is controlled through an extrusion tube and then deposited at the desired location as described in U.S. Pat. No. No. 5,141,680 is included herein as a reference in its entirety. Foil-based methods attach coats by using, e.g. photo polymerization, glue, or other techniques. The object is then cut from these coats, or polymerized. U.S. Pat. describes such a technique. No. No.

AM techniques typically start with a digital representation. The digital representation is usually sliced into cross-sectional layers that can be overlaid to create the entire object. This data is used by the AM apparatus to build the object layer-by-layer. A computer system or computer-aided design and manufacture (CAD/CAM software) can generate the cross-sectional data that represents the layer data for the 3D object.

The basic structure of the lattice can be made from any material compatible with additive manufacturing that is capable of providing sufficient stiffness to the rigid shapes of the lattice structures in either the free-form or whole structure. Suitable materials include, but are not limited to, e.g., polyurethane, acrylonitrile butadiene styrene (ABS), polycarbonate (PC), PC-ABS, polyamide, polyamide with additives such as glass or metal particles, methyl methacrylate-acrylonitrile-butadiene-styrene copolymer, etc.”

The lattice structure may consist of a rigid structure with an open framework, such as 3D printed lattices. A plurality of lattice cells may be contained in lattice structures, including dozens, thousands or hundreds of thousands. lattice cells. After the 3D model is created, STL files can be generated to print the lattice model. Before optimizing and placing the lattice, the system will identify where material is required in an appliance.

The system can optimize dental lattices by applying two phases. It first applies a topology optimization that allows porous materials with intermediate densities to be present. The porous zones are then transformed into explicit lattice structures of varying material volumes. The second phase optimizes the dimensions of the lattice cell. This results in a structure that has solid parts and lattice zones containing varying amounts of material. This system can balance the relationship between material density and part performance, such as with respect to stiffness to volume ratio. This can have an impact on design decisions made early in product development. For biomedical implants, porosity is a critical requirement. For products that require more than stiffness, lattice zones may be crucial. The system can optimize buckling behavior and dynamic characteristics. Based on the optimization results, the user can alter material density to compare stronger or weaker designs, as well as void versus lattice. First, the designer defines the goal and then performs optimization analysis to inform design.

While 3D printing is possible, lattices can also consist of strips, bars and girders. Although the strips, bars and girders of beams may be straight, they can also be curved. The lattice may not be made up of longitudinal beams. It could also include interconnected spheres or pyramids. Among others.

“The lattice is a structure that contains a repeating, regular pattern like the one shown in FIG. 8A shows how the pattern can be defined using a specific unit cell. A unit cell is the simplest repeating unit in the pattern. The lattice structure 124 can be described as a plurality unit cells. The shape of the unit cells depends on the stiffness required. They can be monoclinic, orthorhombic or tetragonal, rhombohedral and hexagonal, as well as cubic. The lattice structures’ unit cells typically have a volume of 1 to 8000mm3, but preferably 8 to 3375mm3, more preferably 64 to 33375mm3, and most preferably 64 to 1728mm3. Along with other factors like material choice and unit cell geometrie, the size of the unit cells can determine the rigidity (stiffness), and transparency of the freeform structure. Smaller unit cells tend to increase rigidity, decrease transparency and increase rigidity. Larger units cells have a tendency to decrease rigidity, increase transparency and increase rigidity. In order to give the regions a certain stiffness, there may be local variations in unit cell size and/or geometry. The lattice 124 could contain one or more repeat unit cells as well as one or two unique unit cells. The thickness or diameter of the strips, bars and girders, beams, or similar may be greater than 0.1 mm to help ensure stability of the lattice structure. Particular embodiments may require that the thickness or diameter of the strips, bars and girders, beams, or similar, be at least 0.2 mm. 0.4 mm. 0.6 mm. 0.8 mm. 1 mm. 1.5 mm. 2 mm. 3 mm. 5 mm. The lattice structure (124) is designed to provide stiffness for the free-form structure. Because it is an open framework, the lattice structure (124) may enhance or guarantee transparency. While the lattice structure (124) can be viewed as a reticulated structure with the appearance and/or form of a net or grid but other configurations are possible.

“The stiffness and strength of the lattice structure is dependent on factors like the structure density. This depends on the unit cells geometry, the dimensions of the units, as well as the dimensions of the strips bars, girders, beams, and other dimensions. Framework 132. Another factor is S, which refers to the distance between strips and similar, or, in other words, how large are the openings in lattice structures. As shown in FIG. 8B. 8B. The lattice structure is an unstructured framework that includes openings 134. The opening size of the lattice structure in particular embodiments is between 1 and 20mm, 2 to 15mm, and 4 to 15mm. Preferable embodiments have an opening size between 4 and 12 millimeters. In some embodiments, the opening size may be equal or smaller than the size unit cell 134. However, in other embodiments the openings can be uniform or arbitrary in size. Another alternative is that different regions of the lattice could have openings that are identical in size, but are different from others.

“In particular embodiments, free-form structures can include a lattice structure with one or more interconnected layers of reticulated, as shown in FIG. 8C. 8C. 8C. Within the lattice structure. The number of layers within the lattice structure can affect the degree of stiffness. Further, free-form structures can include more than one lattice. These examples are only representative of different embodiments.

“For some applications, the lattice structure might also include one or more holes that are larger than the openings and unit cells described above. Alternately, the lattice may not cover the entire structure of the free-form structure so that there are no openings in it or areas for handling, such as tabs orridges and/or unsupported coating material. A facial mask is an example of such an application. It has holes at the nose, eyes, and mouth. These holes are not usually filled with the coating material.

“Likewise, in certain embodiments, the sizes of the openings that are impregnated with and/or enclosed in the adjoining material can range from, e.g. 1 to 20 mm. The size of the holes in the lattice structure, which corresponds to the holes in the free form structure, will typically be larger than the size of the unit cell. In particular embodiments, the size of a unit cell can vary between 1 and 20 millimeters.

“Accordingly to certain embodiments, as illustrated in the FIG. 8D. The free-form structure could contain regions 133 made up only of the coating material. This could be useful in areas that require extreme flexibility.

“In certain embodiments, the free-form structure envisaged may contain a basic structure that contains, in addition, a lattice structural, one or more restricted regions that do not contain a lattice structure but are uniform surfaces. As shown in FIG. 8E. These form extensions 135 of the lattice structure in a symmetrical configuration (e.g. rectangular, semi-circle, etc.). These regions typically cover less than 50% or less than 30% or less than 20% of the entire basic structure. They are typically used to handle (manual tabs), and/or place attachment structures (clips or elastic string, for example). In some embodiments, the base structure may consist essentially of a lattice structure.

“It is possible to make the dental appliance structure more rigid in certain areas, such as the molar teeth. This can provide additional force. You can achieve this by creating a lattice with locally variable unit cell geometries, different unit cell dimensions, and/or varied densities (by increasing the number reticulated layers), such as the detail perspective view in FIG. 8F. 8F. Accordingly, particular embodiments provide a lattice structure with different unit cell geometries, various unit cell dimensions, and varying thicknesses of the lattice structures, as well as varying densities (137, 139). As shown in FIG. 8, the thickness of the coating material can also be varied as described. 8G. 8G. Further, in certain embodiments, the freeform structures can have different stiffness regions, but they maintain the same volume and dimensions.

“In particular embodiments, the lattice structures can be covered with a different coating material than the material used to manufacture the lattice. Particular embodiments of the lattice structure are at least partially embedded in or enclosed by the coating material (and optionally immured with it), as shown in FIG. 8H. 8H. Particularly, only certain areas of the basic structure or the lattice structure in a free-form structure are coated with a coating material. Other parts may remain exposed. 145 Particular embodiments may cover at least one surface of the lattice structure or basic structure with a coating material 131, for at least 50% and more specifically at least 80%. Further embodiments cover all areas of the basic structure with a lattice framework completely with the coating material. Further particular embodiments include the complete embedding of the coating material in the basic structure, with the exception of the tabs that are provided for handling.

“In further embodiments, the free form structure includes, in addition to a covered lattice structural, regions of coating material that are not supported by a base structure or a lattice.

In certain embodiments, the free form structure may include at least two materials of different composition or texture. Other embodiments may include a composite structure. This is a structure that is composed of at least two different compositions and/or materials.

“The coating material(s), may be a polymeric, ceramic or metal material. Particular embodiments use a polymeric coating material. Suitable polymers include, but are not limited to, silicones, a natural or synthetic rubber or latex, polyvinylchloride, polyethylene, polypropylene, polyurethanes, polystyrene, polyamides, polyesters, polyepoxides, aramides, polyethyleneterephthalate, polymethylmethacrylate, ethylene vinyl acetate or blends thereof. Particular embodiments of the polymeric material include silicone, polyurethane or polyepoxide as well as polyamides and blends thereof.

“In particular, the free-form structures may include more than one coating material or combinations thereof.”

“In certain embodiments, the coating material may be a silicone. Silicones are usually inert which makes it easier to clean the free-form structure.

“In particular embodiments, the coating materials are an optically transparent polymeric substance. Optically transparent is a term that refers to a material that is transparent. Optically transparent is a material layer with a thickness of at least 5mm that can be seen by unaided visual inspection. This layer should transmit at least 70% of incident visible light (electromagnetic waves with wavelengths between 400 and 760 nanometers) without diffusing it. A UV-Vis Spectrophotometer can measure the transmission of visible light and thus the transparency. This is if the person who is skilled in the art has the ability to do so. Transparent materials can be used to treat wounds, especially when they are free-form. Polymers can be made from one type of monomer or oligomer or prepolymer with optionally additional additives or from a combination of monomers, monomers, prepolymers or prepolymers with optionally additional additives. Optional additives could include a blowing agents and/or one or several compounds that can generate a blowing agency. For the production of foam, blowing agents are used.

“Accordingly in particular embodiments, the coating materials are present in the free form structure in the shape of a foam, preferably an foamed solid. In particular embodiments, the foamed solid is used to coat the lattice structure. Foamed materials offer certain advantages over solid material: they have lower density, use less material and have better insulation properties than solid materials. Foamed solids can also absorb impact energy and are useful in the production of protective elements, such as free-form structures. A polymeric material, ceramic material or metal can make up the foamed solid. The foamed solid should contain one or more polymeric material.

Open cell structured foams, also known as reticulated or closed cell foams, are two options. The pores in open cell structured foams are interconnected and create a network that is relatively soft. Closed cell foams are stronger and denser than open cell structures foams. They do not have interconnected pores. The foam can be used in particular embodiments as an “integral skin foam”, also known as “self-skin foam” (e.g., a foam that has a high-density outer layer and a dense inner layer).

“In particular embodiments, free form structures can include a base structure that includes a lattice structure that is at least partially covered with a polymeric material or another material. In some cases, it is not necessary to determine the thickness of the coating and the uniformity in the coating’s layer thickness. For certain applications, however, it may be beneficial to apply a layer of coating material with a modified layer thickness at one or more points of the free form structure to increase flexibility and fit the free-form structures on the body.

The freeform structures described herein can be constructed as one rigid, free-form piece that does not require any liner or other elements. The free-form structures may also be equipped with sensors, straps or other features to maintain the structure in its intended position. 8I. 8I.

“In some embodiments, the free form structure is a single rigid lattice structure. Other layers may be interconnected with reticulated material. These structures are often rigid and limited in flexibility. This can cause discomfort for the person or animal who wears them. A free-form structure that has two or more rigid lattice structures can allow for greater flexibility. The material used to create the free-form structure is then used to cover it. Each of the lattice structure provides rigidity to the free-form structure. However, flexibility is provided by the (limited) movement between the lattices. These embodiments will usually ensure that the lattice frameworks remain attached to one another, regardless of whether the coating material or a less restrictive lattice structure is used.

“In certain embodiments, the lattice structure is partially or fully overlapping. In some embodiments, however, the lattices are not overlapping. Further, in particular embodiments, the lattice structure can be connected to one another, for example, via a hinge, or other movable mechanism (149, 149?). As shown in FIG. 83. Particular embodiments ensure that the connection is made by lattice material. Further, the lattice structure may be connected by one or more beams that extend the lattice structure. The coating material is used to hold the lattice structure together in a free-form structure. A facial mask that has a jaw structure that can be moved relative to the rest of its mask is an example of such a free form structure. In particular embodiments, the lattice framework comprises at least two separate lattice arrangements that are movably connected to one another. The lattice structures are then integrated into the free form structure as shown.

The free-form structure can be used to treat wounds as described in this article. The free-form structure allows for uniform pressure and/or contact at the wound site. It is easy to integrate pressure sensors into the free form structure of the invention using the lattice structure. Sensors can be external, but they may also be internal. The lattice structure can be designed so that multiple sensors can be mounted at specific locations.

“Additionally, or alternatively, the free form structure can include one or more sensors, as shown in FIG. 8I may include a temperature sensor or moisture sensor as well as an optical sensor. For example, accelerometers, GPS sensors, step counters and gyroscopes can be used to monitor activity. To monitor wound healing, temperature sensors, moisture sensors and strain gauges can be used. The optical sensor(s), as described in US Pat., may be used to determine the structure of collagen fibers. App. App.

“Accordingly, the free-form structure may also include one or more internal and/or external sensors. The free-form structure may include one or more sensors within it. In some embodiments, the free form structure includes one or more temperature and/or pressure sensors.

“The skilled person will know that, in addition to the sensor(s), associated power sources, and/or means of transmitting signals from the sensor(s), to a receiver device may also be included in the free-form structure such as wiring, radio transmitters and infrared transmitters.

“In certain embodiments, at most one sensor may include micro-electronic mechanic systems (MEMS technology), i.e. technology that integrates mechanical systems with micro-electronics. MEMS-sensors are sensors based on MEMS technology. These sensors are small, light and require very little power. The STTS751 temperature sensor, and the LIS302DL accelerometer STMicroelectronics are two examples of MEMS-sensors that work well.

“As shown at FIG. 8K, the lattice design also allows for the free-form structure to be provided with one or more internal channels 151. These channels can be used to deliver treatment agents to the skin, tissue, and teeth. These channels can also be used to circulate fluids such as cooling or heating fluids.

“Differential Force” is one philosophy in orthodontic treatment. The Differential Force approach to orthodontic treatment calls for corrective forces to be tailored to each tooth’s unique force requirements. Hardware based on calibrated springs was used to support the Differential Force approach. The Differential Force concept can be extended to aligner fabrication. CNC-machined aligners with carefully controlled variable thickness can achieve the Differential Force goals on a tooth by tooth basis. A technician can determine the wall thickness of the compartments around teeth at the CAD/CAM level based on each tooth’s needs. An unlimited number of regions can be printed 3D, with each having a unique offset thickness.

“A practitioner will assess the progress of the case before installing such devices. For example, they may note areas that are slowing down or where certain teeth refuse to move in response to treatment forces. A group of small devices can be 3D printed using an aligner’s framework. These devices are called “aligner auxiliaries.” FIG. FIG. 9 shows a detailed view of an alignment 140 that includes a 3D-printed area 142. This allows thicker material to be used for elastic 144. Another 3D-printed geometries that are of interest include pressure points or divots, openings on the aligner to allow for a combination treatment. For example, hooks for elastic bands can be formed on the aligner. To enhance correction, aligner auxiliaries can be placed in these locations. An auxiliary, also known as a “tack”, can be installed by drilling a hole of a certain diameter through the wall of a compartment of aligner that contains teeth. The hole’s diameter may be slightly smaller than the shank portion of the tack, which can be printed directly onto the aligner. These progressively-sized tacks, as well as other auxiliary devices, are available commercially to orthodontists to enhance and extend the tooth positioning correcting forces of aligners.

“Bumps can be used to concentrate energy in the area of the aligner structure that is adjacent to a bump. An aligner material will be flexed in an area away from the tooth’s surface by the inward-projecting bump. This configuration allows bumps to gather energy from a larger area and direct corrective forces at the most efficient point. As shown in FIGS. 2 and 3, an elastic hook feature 150 can easily be 3D printed in an otherwise unadorned area of an aligner?s structure. 10A and 10B. As needed, elastic hooks can be used as anchor points to orthodontic elastics. They provide tractive forces between the sectioned sections of an aligner or other fixed structures attached to the teeth.

“Aside form hook features 150, other features like suction features 152 may also be fabricated to adhere to particular teeth T. As shown in FIG.’s partial cross-sectional view, FIG. 10C. 10C.

“In another embodiment, as shown at FIG. 10D, the aligner’s occlusal surfaces may be designed to allow the patient to eat or talk. These features could include thinned, flattened, or enlarged occlusal areas 156 to aid eating.

“Additionally different parts of the aligners can be manufactured to have different areas 160 f varying friction. As shown in FIG. 10E. These varying areas can be created, e.g. along the edges, to prevent the alignment material from tearing.”

Additional attachments, such as particulate coatings, can be made on 3D-printed dental appliances. The particulate coating 162 can be applied to the tooth-engaging surface of the 3D printed lattice appliance in any suitable manner, such as fusion, sintering or other methods, as shown in FIG. 10F. The coating can be made of any shape of particles, including spherical or irregular shapes. It may also be made of metal (including alloys), ceramic, polymer or a combination of both. Particulate coatings adhere to tooth-engaging surfaces in a variety of ways. They can be either discrete particles that are separated from one another on the surface or layers or multiple layers of particles that have been bonded together to form a network of interconnected pores. A porous interface allows fluid bonding resin to flow and penetrate through the particulate coating. After the resin has cured to solid state, mechanical interlock between the resin and the particulate layer is achieved. In certain cases, chemical bonding can be achieved in addition to mechanical bonding, such as by using polycarboxylate and glass ionomer cements together with stainless steel and other metal substrates, and with ceramic substrates.

“A coating of integrally-joined particle which makes up a porous structure with a plurality interconnected pores extending therethrough, is usually around?100 mesh. Preferably, a mixture particles of different sizes, restricted to one of the following size ranges:?100+325 mesh,?325+500, (about 20 to 50 microns), or?500 mesh (less that 20 microns). The pore sizes between particles will depend on their size. Fluid resin bonding agents prefer smaller pores, while cementitious bonding materials require larger pores. To control porosity, the particle size can be adjusted to within a range of 10 to 50% volume.

“The composite of substrate, coating and resin must have sufficient structural strength so that fractures of the bracket and tooth joint occur in the resin and the coating. This condition can be achieved by ensuring that the structural strength of the coating (the interface between the substrate and the coating) is at least 8 MPa.

The devices and methods described above can be used for a variety of other treatment purposes. These devices and methods can also be used to treat other areas of the body. Modifications to the described assemblies and methods of carrying out the invention, as well as combinations between various variations, and variations of aspects that are obvious to those skilled in the art, are all within the scope and scope of the claims.

Summary for “Three-dimensional, printed dental appliances with support structures”