Orthodontic appliances and materials
An orthodontic appliance shaped to receive teeth. The orthodontic appliance can be constructed from a laminate structure with a outer transparent layer and an inner translucent layer. The translucent layer can scatter light to decrease a relative degree or perceived gloss to the human eye, and hence provide a more natural appearance to the orthodontic appliance.
1 . A method for forming an orthodontic appliance to have a color and gloss resembling natural teeth, the method comprising:
placing a laminate material into an orthodontic appliance thermoforming device, wherein, before thermoforming, the laminate material comprises:
a first layer comprising a first thermoplastic material having a transparent appearance;
a second layer comprising a second thermoplastic material, the second thermoplastic material having a non-transparent appearance; and
a third layer comprising the first thermoplastic material, wherein the second layer is between the first and third layer;
determining a target degree of translucence of the orthodontic appliance to resemble a color and gloss of natural teeth;
selecting thicknesses of the first, second, and third layers;
thermoforming the laminate material into the orthodontic appliance according to pressure, heating, and time settings of the orthodontic appliance thermoforming device,
wherein the thicknesses of the first, second, and third layers, as well as at least the heating and time settings, are selected to tune translucence of the orthodontic appliance to the target degree of translucence to resemble a color and gloss of natural teeth,
wherein the thicknesses of the first, second, and third layers are selected to mitigate gloss to resemble the gloss of natural teeth,
wherein the first thermoplastic material of the first and third layers is a transparent copolyester and the second thermoplastic material of the second layer is a thermoplastic copolyester that is opaque prior to thermoforming,
wherein the thermoforming causes the second thermoplastic material to increase in relative decrystallization with increased heating time and thereby increase relative translucency and relative transparency of the second layer; and
wherein the heating and time settings are selected to tune a translucence appearance of the second layer by increasing the relative decrystallization of the second layer such that the second thermoplastic material of the orthodontic appliance transitions during thermoforming from the non-transparent appearance to a translucent appearance that provides the target degree of translucence to resemble a color and gloss of natural teeth.
2 . The method of claim 1 , wherein the second thermoplastic material is crystallized, and wherein at least the heating and time settings are selected to at least partially decrystallize the second thermoplastic material of the second layer to provide the translucent appearance.
3 . The method of claim 1 , wherein increasing an amount of heat energy applied to the laminate material and/or increasing the amount of time the laminate material is heated causes the second thermoplastic material to have greater relative translucency.
4 . The method of claim 1 , wherein the heating settings comprises 220° C. (427° F.).
5 . The method of claim 1 , wherein the time setting comprises a heating time of 30-60 seconds.
6 . The method of claim 1 , wherein the second thermoplastic material comprises a thermoplastic copolyester.
7 . The method of claim 1 , wherein a relative degree of translucency of the second thermoplastic material of the orthodontic appliance is based on a degree of a structure of the second thermoplastic material being crystallized.
8 . The method of claim 1 , wherein the second thermoplastic material is configured to decrystallize when being thermoformed by the commercially available thermoforming device at a heat setting of 220° C.
9 . The method of claim 1 , wherein the orthodontic appliance has a hazed white appearance resulting from the at least the heating and time settings that are selected to tune translucence of the orthodontic appliance to the target degree of translucence by making the second thermoplastic material of the orthodontic appliance transition from the non-transparent appearance to a translucent appearance of the target degree of translucence, wherein the orthodontic appliance is absent colorants for providing the target degree of translucence.
10 . The method of claim 1 , wherein the orthodontic appliance has a milky appearance resulting from the at least the heating and time settings that are selected to tune translucence of the orthodontic appliance to the target degree of translucence by making the second thermoplastic material of the orthodontic appliance transition from the non-transparent appearance to a translucent appearance of the target degree of translucence, wherein the orthodontic appliance is absent colorants for providing the target degree of translucence.
11 . The method of claim 1 , wherein the second thermoplastic material of the second layer of the orthodontic appliance comprises a structure arranged to scatter light to reduce perceived visual gloss effects from a perspective of a viewer of the orthodontic appliance, wherein the structure results from the at least the heating and time settings that are selected to tune translucence of the orthodontic appliance to the target degree of translucence by making the second thermoplastic material of the orthodontic appliance transition from the non-transparent appearance to a translucent appearance of the target degree of translucence, wherein the orthodontic appliance is absent colorants for providing the target degree of translucence.
12 . The method of claim 1 , wherein the laminate has a thickness of 0.030 inches prior to thermoforming, wherein the first layer and the third layer are formed from a transparent copolyester having a thickness of 0.010 inches prior to thermoforming, and wherein the second layer is formed from a thermoplastic copolyester having a thickness of 0.010 inches prior to thermoforming.
13 . The method of claim 1 , wherein the selected heating and time settings comprises a heating time within 30-60 seconds.
14 . The method of claim 13 , wherein the selected thicknesses of the first and third layers are 0.010-0.015 inches, and the selected thickness of the second layer is 0.010 inches.
15 . The method of claim 13 , wherein the selected heating and time settings comprises a heating temperature of approximately 427 degrees Fahrenheit.
16 . The method of claim 15 , wherein the selected heating and time settings comprises a cooling time of 100-140 seconds.
17 . The method of claim 1 , wherein the second thermoplastic material of the second layer consists of a thermoplastic copolyester (TPC/TPE-E) and the first thermoplastic material of the first and third layers consist of a transparent polyethylene terephthalate glycol-modified (PETG).
18 . The method of claim 17 , wherein the selected heating and time settings comprises a heating temperature of approximately 427 degrees Fahrenheit, and wherein the selected heating and time settings comprises a heating time within 45-50 seconds and a cooling time of 100-140 seconds.
19 . The method of claim 18 , wherein the laminate has a thickness of 0.040 inches prior to thermoforming, wherein the selected thicknesses of the first and third layers are 0.015 inches, and the selected thickness of the second layer is 0.010 inches.