Multilayer dental appliances and related methods and systems

Abstract

A dental appliance for positioning a patient's teeth includes a removable orthodontic tooth positioning appliance having teeth receiving cavities shaped to directly receive at least some of the patient's teeth and apply a resilient positioning force to the patient's teeth. The appliance includes a hard polymer layer having a hard polymer layer elastic modulus disposed between a first soft polymer layer having a first soft polymer layer elastic modulus and a second soft polymer layer having a second soft polymer layer elastic modulus. The hard polymer layer elastic modulus is greater than each of the first soft polymer layer elastic modulus and the second soft polymer layer elastic modulus. At least one of the first soft polymer layer and the second soft polymer layer has a flexural modulus of greater than about 35,000 psi.

What is claimed is: 
     
         1 . An orthodontic appliance comprising teeth receiving cavities shaped to directly receive at least some of a patient's teeth and apply a resilient positioning force to the patient's teeth, the orthodontic appliance comprising:
 a first outer polymer layer comprising a first polymeric material and a second outer polymer layer comprising a second polymeric material, each of the first and second outer polymer layers having an ultimate tensile strength of greater than about 5000 psi, an elongation at break of greater than about 200%, and a hardness of about 60 A to about 85 D; and   an inner polymer layer comprising a third polymeric material comprising a tensile modulus greater than 150,000 psi and a flexural modulus greater than about 150,000 psi.   
     
     
         2 . The orthodontic appliance of  claim 1 , wherein the first outer polymer layer comprises a first polymer layer elastic modulus, the second outer polymer layer comprises a second polymer layer elastic modulus, and the inner polymer layer comprises a third polymer layer elastic modulus, and wherein each of the first polymer layer elastic modulus and the second polymer layer elastic modulus are less than the third polymer layer elastic modulus. 
     
     
         3 . The orthodontic appliance of  claim 1 , wherein at least one of the first outer polymer layer and the second outer polymer layer comprises a thermoplastic polyurethane elastomer. 
     
     
         4 . The orthodontic appliance of  claim 1 , wherein the inner polymer layer comprises a co-polyester. 
     
     
         5 . The orthodontic appliance of  claim 1 , wherein at least one of the first outer polymer layer and the second outer polymer layer comprises one or more of: a flexural modulus of greater than about 35,000 psi, a compression set greater than 40% after 24 hours at 70° C., or a light transmission between 400 nm and 800 nm of greater than about 75%. 
     
     
         6 . The orthodontic appliance of  claim 1 , wherein at least one of the first outer polymer layer and the second outer polymer layer comprises a material selected from the group consisting of: a thermoplastic polyurethane elastomer, a silicone rubber, an elastomeric alloy, a thermoplastic elastomer (TPE), a thermoplastic vulcanizate (TPV) elastomer, a block copolymer elastomer, a polyolefin blend elastomer, a thermoplastic co-polyester elastomer, and a thermoplastic polyamide elastomer, or a combination thereof. 
     
     
         7 . The orthodontic appliance of  claim 1 , wherein at least one of the first outer polymer layer and the second outer polymer layer comprises a blend of polymeric materials, including two or more materials selected from the group consisting of: a thermoplastic polyurethane elastomer, a silicone rubber, an elastomeric alloy, a thermoplastic elastomer (TPE), a thermoplastic vulcanizate (TPV) elastomer, a block copolymer elastomer, a polyolefin blend elastomer, a thermoplastic co-polyester elastomer, and a thermoplastic polyamide elastomer. 
     
     
         8 . The orthodontic  1  appliance of  claim 1 , wherein the third polymeric material comprises a polymer selected from the group consisting of: a co-polyester, a polyester, a thermoplastic polyurethane, a polypropylene, a polyethylene, a polypropylene and polyethylene copolymer, an acrylic, a polyetheretherketone, a polyamide, a polyethylene terephthalate, a polybutylene terephthalate, a polyetherimide, a cyclic block copolymer, a polyethersulfone, and a polytrimethylene terephthalate, or a combination thereof. 
     
     
         9 . The orthodontic appliance of  claim 1 , wherein the inner polymer layer comprises a blend of polymeric materials, including two or more materials selected from the group consisting of: a polyester, a co-polyester, a thermoplastic polyurethane, a polypropylene, a polyethylene, a polypropylene and polyethylene copolymer, an acrylic, a polyetheretherketone, a polyamide, a polyethylene terephthalate, a polybutylene terephthalate, a polyetherimide, a cyclic block copolymer, a polyethersulfone, and a polytrimethylene terephthalate. 
     
     
         10 . The orthodontic appliance of  claim 1 , wherein the inner polymer layer comprises at least two layers, and wherein each of the at least two layers of the inner polymer layer independently comprises a polymeric material selected from the group consisting of: a polyester, a co-polyester, a thermoplastic polyurethane, a polypropylene, a polyethylene, a polypropylene and polyethylene copolymer, an acrylic, a polyetheretherketone, a polyamide, a polyethylene terephthalate, a polybutylene terephthalate, a polyetherimide, a cyclic block copolymer, a polyethersulfone, and a polytrimethylene terephthalate, or a combination thereof. 
     
     
         11 . The orthodontic appliance of  claim 1  comprising a thickness of between 500 μm and 1200 μm. 
     
     
         12 . The orthodontic appliance of  claim 1 , wherein the inner polymer layer comprises at least one of: an elongation at yield of greater than about 4%, an elongation at break of greater than about 70%, a stress relaxation of greater than about 10% at 24 hours testing at a relative humidity of between 90% and 100%, a light transmission between 400 nm and 800 nm of greater than about 75%, or a tensile strength at yield between 4000 psi and 6500 psi. 
     
     
         13 . A plurality of incremental position adjustment appliances having teeth receiving cavities shaped to directly receive at least some of a patient's teeth and apply a resilient positioning force to the patient's teeth, wherein the incremental position adjustment appliances are shaped to move teeth from one arrangement to a successive arrangement when successively worn by the patient, and wherein at least one of the incremental position adjustment appliances comprises:
 a first outer polymer layer comprising a first polymeric material and a second outer polymer layer comprising a second polymeric material, each of the first and second outer polymer layers having an ultimate tensile strength of greater than about 5000 psi, an elongation at break of greater than about 200%, and a hardness of about 60 A to about 85 D; and   an inner polymer layer comprising a third polymeric material comprising a tensile modulus greater than 150,000 psi and a flexural modulus greater than about 150,000 psi.   
     
     
         14 . The plurality of incremental position adjustment appliances of  claim 13 , wherein the first outer polymer layer comprises a first polymer layer elastic modulus, the second outer polymer layer comprises a second polymer layer elastic modulus, and the inner polymer layer comprises a third polymer layer elastic modulus, and wherein each of the first polymer layer elastic modulus and the second polymer layer elastic modulus are less than the third polymer layer elastic modulus. 
     
     
         15 . The plurality of incremental position adjustment appliances of  claim 13 , wherein at least one of the first outer polymer layer and the second outer polymer layer comprises a thermoplastic polyurethane elastomer. 
     
     
         16 . The plurality of incremental position adjustment appliances of  claim 13 , wherein the inner polymer layer comprises a co-polyester. 
     
     
         17 . The plurality of incremental position adjustment appliances of  claim 13 , wherein at least one of the first outer polymer layer and the second outer polymer layer comprises one or more of: a flexural modulus of greater than about 35,000 psi, a compression set greater than 40% after 24 hours at 70° C., or a light transmission between 400 nm and 800 nm of greater than about 75%. 
     
     
         18 . The plurality of incremental position adjustment appliances of  claim 13 , wherein at least one of the first outer polymer layer and the second outer polymer layer comprises a material selected from the group consisting of: a thermoplastic polyurethane elastomer, a silicone rubber, an elastomeric alloy, a thermoplastic elastomer (TPE), a thermoplastic vulcanizate (TPV) elastomer, a block copolymer elastomer, a polyolefin blend elastomer, a thermoplastic co-polyester elastomer, and a thermoplastic polyamide elastomer, or a combination thereof. 
     
     
         19 . The plurality of incremental position adjustment appliances of  claim 13 , wherein the inner polymer layer comprises at least one of: an elongation at yield of greater than about 4%, an elongation at break of greater than about 70%, a stress relaxation of greater than about 10% at 24 hours testing at a relative humidity of between 90% and 100%, a light transmission between 400 nm and 800 nm of greater than about 75%, or a tensile strength at yield between 4000 psi and 6500 psi. 
     
     
         20 . A method of moving a patient's teeth from an initial configuration towards a target configuration, the method comprising:
 providing a removable orthodontic tooth positioning appliance having teeth receiving cavities shaped to directly receive at least some of a patient's teeth; and   placing the removable orthodontic tooth positioning appliance on the teeth of the patient to apply a resilient positioning force to the patient's teeth and thereby move the teeth towards the target configuration, wherein the removable orthodontic tooth positioning appliance comprises:
 a first outer polymer layer comprising a first polymeric material and a second outer polymer layer comprising a second polymeric material, each of the first and second outer polymer layers having an ultimate tensile strength of greater than about 5000 psi, an elongation at break of greater than about 200%, and a hardness of about 60 A to about 85 D; and 
 an inner polymer layer comprising a third polymeric material comprising a tensile modulus greater than 150,000 psi and a flexural modulus greater than about 150,000 psi. 
   
     
     
         21 . The method of  claim 20 , wherein providing the removable orthodontic tooth positioning appliance comprises providing a series of incremental position adjustment appliances, said series of incremental position adjustment appliances including the removable orthodontic tooth positioning appliance. 
     
     
         22 . The method of  claim 21 , wherein providing the series of incremental position adjustment appliances comprises placing said series of incremental position adjustment appliances over the patient's teeth. 
     
     
         23 . The method of  claim 20 , wherein at least one of the first outer polymer layer and the second outer polymer layer comprises one or more of: a flexural modulus of greater than about 35,000 psi, a compression set greater than 40% after 24 hours at 70° C., or a light transmission between 400 nm and 800 nm of greater than about 75%. 
     
     
         24 . The method of  claim 20 , wherein the inner polymer layer comprises at least one of: an elongation at yield of greater than about 4%, an elongation at break of greater than about 70%, a stress relaxation of greater than about 10% at 24 hours testing at a relative humidity of between 90% and 100%, a light transmission between 400 nm and 800 nm of greater than about 75%, or a tensile strength at yield between 4000 psi and 6500 psi. 
     
     
         25 . The method of  claim 20 , further comprising fabricating the removable orthodontic tooth positioning appliance. 
     
     
         26 . The method of  claim 20 , wherein the first outer polymer layer comprises a first polymer layer elastic modulus, the second outer polymer layer comprises a second polymer layer elastic modulus, and the inner polymer layer comprises a third polymer layer elastic modulus, and wherein each of the first polymer layer elastic modulus and the second polymer layer elastic modulus are less than the third polymer layer elastic modulus. 
     
     
         27 . The method of  claim 20 , wherein at least one of the first outer polymer layer and the second outer polymer layer comprises a thermoplastic polyurethane elastomer. 
     
     
         28 . The method of  claim 20 , wherein the inner polymer layer comprises a co-polyester. 
     
     
         29 . The method of  claim 20 , wherein at least one of the first outer polymer layer and the second outer polymer layer comprises a material selected from the group consisting of: a thermoplastic polyurethane elastomer, a silicone rubber, an elastomeric alloy, a thermoplastic elastomer (TPE), a thermoplastic vulcanizate (TPV) elastomer, a block copolymer elastomer, a polyolefin blend elastomer, a thermoplastic co-polyester elastomer, and a thermoplastic polyamide elastomer, or a combination thereof. 
     
     
         30 . The method of  claim 20 , wherein the inner polymeric material comprises a polymer selected from the group consisting of: a co-polyester, a polyester, a thermoplastic polyurethane, a polypropylene, a polyethylene, a polypropylene and polyethylene copolymer, an acrylic, a polyetheretherketone, a polyamide, a polyethylene terephthalate, a polybutylene terephthalate, a polyetherimide, a cyclic block copolymer, a polyethersulfone, and a polytrimethylene terephthalate, or a combination thereof.