Direct fabrication of orthodontic appliances with elastics
Improved orthodontic appliances, along with related systems and methods, are provided. In one aspect, an appliance includes a shell having a plurality of cavities shaped to receive teeth, a discontinuity formed in the shell, and an elastic member positioned to interact with the discontinuity. In another aspect, an appliance includes a plurality of discrete shell segments joined by an elastic material to form a single appliance shell. In another aspect, an appliance includes a shell having an exterior layer and an interior layer having a stiffness less than a stiffness of the exterior layer, and a discontinuity formed in the exterior layer. In another aspect, an appliance includes a shell comprising an interior surface and an exterior surface, and an elastic coating covering at least a portion of one or more of the interior surface or exterior surface of the shell.
1. A method comprising:
generating a digital model related to a treatment plan to treat a patient's teeth, wherein the digital model comprises:
a digital representation of the patient's teeth at one or more treatment stages of the treatment plan,
a digital representation of a discontinuity to be formed in a shell including a plurality of cavities configured to receive and resiliently reposition the patient's teeth, and
a digital representation of an elastic member configured to interact with the discontinuity; and
generating, based on the digital model, instructions to fabricate, using an additive manufacturing technique, the elastic member and the shell, including to fabricate at least a part of the shell and the elastic member joined together.
2. The method of claim 1 , wherein the additive manufacturing fabrication technique comprises one or more of: vat photopolymerization, material jetting, binder jetting, fused deposition modeling, powder bed fusion, sheet lamination, or directed energy deposition.
3. The method of claim 1 , wherein the instructions are configured to cause a fabrication machine to concurrently fabricate the shell and the discontinuity using the additive manufacturing fabrication technique.
4. The method of claim 3 , wherein the instructions are configured to cause the fabrication machine to couple the elastic member to the shell after fabricating the shell and the discontinuity.
5. The method of claim 4 , wherein the digital model further comprises a digital representation of an interface shaped to facilitate coupling of the elastic member to the at least the part of the shell.
6. The method of claim 1 , wherein the instructions are configured to cause a fabrication machine to concurrently fabricate the shell and elastic member using the additive manufacturing fabrication technique.
7. The method of claim 1 , wherein the instructions are configured to cause a fabrication machine to fabricate the shell from a first material and the elastic member from a second material, wherein the first material has a greater stiffness than the second material.
8. The method of claim 1 , wherein the discontinuity comprises an aperture or cut in the shell.
9. The method of claim 8 , wherein a portion of the elastic member spans the aperture or cut.
10. The method of claim 1 , wherein the digital model further comprises a digital representation of one or more auxiliary components formed in or coupled to the shell, the one or more auxiliary components comprising one or more of: a channel, a guide feature, a fastening feature, a flap, a receptacle, a retention feature, a telescoping feature, an interproximal feature, or a biasing feature.
11. The method of claim 1 , wherein the digital representation of the patient's teeth represents the shell.
12. The method of claim 1 , wherein the elastic member is configured to control application of repositioning forces exerted by the shell.
13. The method of claim 1 , wherein the elastic member comprises an elastic coating.
14. A method comprising:
gathering a digital model related to a treatment plan to treat a patient's teeth wherein the digital model comprises:
a digital representation of the patient's teeth at a plurality of treatment stages of the treatment plan;
a digital representation of a plurality of discontinuities to be formed in a plurality of shells for each of the plurality of treatment stages, each of the plurality of shells including a plurality of cavities configured to receive and resiliently reposition the patient's teeth; and
a digital representation of a plurality of elastic members configured to interact with the plurality of discontinuities at each of the plurality of treatment stages; and
generating, based on the digital model, instructions to fabricate, using an additive manufacturing technique, a first elastic member of the plurality of elastic members and a first shell of the plurality of shells for a first treatment stage of the plurality of treatment stages, with at least a part of the first shell being joined to the first elastic member when fabricated.
15. The method of claim 14 , further comprising: generating, based on the digital model, instructions to fabricate, using the additive manufacturing technique, a second elastic member of the plurality of elastic members and a second shell of the plurality of shells for a second treatment stage of the plurality of treatment stages, with at least a part of the second shell being joined to the second elastic member.
16. The method of claim 15 , wherein the first and second treatment stages are successive treatment stages of the treatment plan.
17. The method of claim 15 , wherein a first discontinuity of the plurality of discontinuities corresponding to the first shell resides at a first location on the first shell, and a second discontinuity of the plurality of discontinuities corresponding to the second shell resides at a second location on the second shell, and the second location is different than the first location.
18. The method of claim 14 , wherein the digital representation of the patient's teeth represents one or more of the plurality of shells.
19. The method of claim 14 , wherein the plurality of elastic members are configured to control application of repositioning forces exerted by the plurality of shells.
20. The method of claim 14 , wherein the additive manufacturing technique comprises forming the first elastic member and the first shell without using a physical template to define a geometry of the first shell.
21. The method of claim 14 , wherein the first elastic member comprises multiple materials and the additive manufacturing technique comprises multi-material direct fabrication.