Methods for curing dental appliances

A method of curing a polymeric dental appliance, the polymeric dental appliance having one or more partially cured photopolymerizable components, comprising:

• (a) applying at least one liquid photopolymerizable composition to at least one portion of the polymeric dental appliance;
• (b) placing the polymeric dental appliance in a curing chamber of a curing apparatus having one or more controllable heating sources and one or more controllable LED light sources, wherein the one or more controllable LED light sources is capable of emitting light in the ultraviolet and/or visible wavelength range;
• (c) performing a tack curing step in the curing chamber, wherein the one or more controllable LED light sources emits light in the ultraviolet and/or visible wavelength range on the at least one liquid photopolymerizable composition of the polymeric dental appliance for a time period of t4, wherein 5 seconds≤t4≤2 minutes, while the heating source is substantially or completely inactive, to at least partially cure the at least one liquid photopolymerizable composition;
• (d) performing a preheating step in the curing chamber, wherein the one or more controllable heating sources heats the polymeric dental appliance in a time period of t1, wherein 1 minute≤t1≤40 minutes, to a temperature T1≥Tg(Lowest), where Tg(Lowest) is a glass transition temperature for one of the one or more partially cured photopolymerizable components having the lowest glass transition temperature value of the one or more partially cured photopolymerizable components, and wherein the one or more controllable LED light sources is substantially or completely inactive from emitting the ultraviolet and/or visible wavelength range during the preheating step until at least the temperature Tg(Lowest) is achieved in the curing chamber;
• and
• (e) performing a curing step in the curing chamber, wherein the one or more controllable heating sources maintains the polymeric dental appliance at a temperature T2≥Tg(Lowest) for a time period of t2, wherein 2 minutes≤t2≤120 minutes, while the one or more controllable LED light sources emits light in the ultraviolet and/or visible wavelength range onto the polymeric dental appliance for a time period of t3, wherein 2 minutes≤t3≤120 minutes, and t3≤t2, wherein the one or more partially cured photopolymerizable components is converted from a partially cured state to a final cured state to form a finally cured polymeric dental appliance.