Methods and systems for fabricating dental appliances having variable stiffnesses

Abstract

Methods for fabricating dental appliances and associated systems are provided. In some embodiments, a method includes defining a plurality of object cross-sections of a dental appliance, and sequentially polymerizing the plurality of object cross-sections to create the dental appliance. The dental appliance can include an outer shell having a plurality of teeth-receiving cavities, and an inner structure coupled to an inner surface of the outer shell. The outer shell can have a first stiffness, and the inner structure can have a second stiffness less than the first stiffness. The sequential polymerization can include integrally forming the outer shell concurrently with the inner structure.

1 . (canceled) 
     
     
         2 . A method comprising:
 defining a plurality of object cross-sections of a dental appliance, wherein the dental appliance comprises:
 an outer shell comprising a plurality of teeth-receiving cavities, wherein the outer shell comprises a first stiffness, and 
 an inner structure coupled to an inner surface of the outer shell, wherein the inner structure comprises a second stiffness less than the first stiffness; and 
   sequentially polymerizing the plurality of object cross-sections to create the dental appliance, wherein the sequentially polymerizing comprises integrally forming the outer shell concurrently with the inner structure.   
     
     
         3 . The method of  claim 2 , wherein:
 the outer shell comprises a first material comprising the first stiffness, and   the inner structure comprises a second material comprising the second stiffness.   
     
     
         4 . The method of  claim 3 , wherein the first material and the second material are the same material, and the first and second stiffnesses are produced by varying a degree of crosslinking of the same material. 
     
     
         5 . The method of  claim 4 , further comprising:
 determining one or more curing parameters to vary the degree of crosslinking of the same material, and   applying the one or more curing parameters while sequentially polymerizing the plurality of object cross-sections to produce the first stiffness of the outer shell and the second stiffness of the inner structure.   
     
     
         6 . The method of  claim 5 , wherein the one or more curing parameters comprise one or more grayscale values. 
     
     
         7 . The method of  claim 3 , wherein the first material and the second material are different materials. 
     
     
         8 . The method of  claim 2 , wherein the sequentially polymerizing comprises depositing and curing a resin in a layer-by-layer manner. 
     
     
         9 . The method of  claim 8 , wherein curing the resin comprises photopolymerizing the resin. 
     
     
         10 . The method of  claim 2 , wherein the dental appliance is an aligner. 
     
     
         11 . The method of  claim 2 , wherein the dental appliance is configured to implement a treatment plan to reposition a patient's teeth from a first arrangement toward a second arrangement. 
     
     
         12 . A system comprising:
 a controller configured to define a plurality of object cross-sections of a dental appliance, wherein the dental appliance comprises:
 an outer shell comprising a plurality of teeth-receiving cavities, wherein the outer shell comprises a first stiffness, and 
 an inner structure coupled to an inner surface of the outer shell, wherein the inner structure comprises a second stiffness less than the first stiffness; and 
   an energy source operably coupled to the controller, wherein the energy source is configured to output energy to sequentially polymerize the plurality of object cross-sections to create the dental appliance, and wherein the sequential polymerization comprises integrally forming the outer shell concurrently with the inner structure.   
     
     
         13 . The system of  claim 12 , wherein:
 the outer shell comprises a first material comprising the first stiffness, and   the inner structure comprises a second material comprising the second stiffness.   
     
     
         14 . The system of  claim 13 , wherein the first material and the second material are the same material, and the first and second stiffnesses are produced by varying a degree of crosslinking of the same material. 
     
     
         15 . The system of  claim 14 , wherein:
 the controller is configured to determine one or more curing parameters to vary the degree of crosslinking of the same material, and   the energy source is configured to output the energy with the one or more curing parameters during the sequential polymerization of the plurality of object cross-sections to produce the first stiffness of the outer shell and the second stiffness of the inner structure.   
     
     
         16 . The system of  claim 15 , wherein the one or more curing parameters comprise one or more grayscale values. 
     
     
         17 . The system of  claim 13 , wherein the first material and the second material are different materials. 
     
     
         18 . The system of  claim 12 , wherein the energy source is configured to cure a deposited resin in a layer-by-layer manner during the sequential polymerization of the plurality of object cross-sections. 
     
     
         19 . The system of  claim 12 , wherein the energy source is a digital light processing source or a laser source. 
     
     
         20 . The system of  claim 12 , wherein the energy comprises light. 
     
     
         21 . The system of  claim 12 , wherein the dental appliance is an aligner.