Abstract: A method for producing orthodontic devices and appliances having a highly accurate fit by building up a plurality of resin layers on a plaster cast comprising applying a first thin layer of a composition comprising a diurethanedimethacrylate prepared from 2,2,4-trimethylhexamethylenediisocyanate and 2-hydroxyethylmethacrylate, and a photopolymerization catalyst to the plaster cast and briefly exposing said thin layer to light whereby said thin layer is partially polymerized, successively applying at least one additional thin layer on said first thin layer and partially polymerizing each successive thin layer by brief exposure until the layer thickness and shape desired for the device or appliance are attained, and the shaped partially polymerized material is subsequently polymerized completely by exposure to light.

Abstract: A method for producing orthodontic devices and appliances by building up a plurality of resin layers on a plaster cast comprising applying a first thin layer of a composition comprising a diurethanedimethacrylate prepared from 2,2,4-trimethylhexamethylenediisocyanate and 2-hydroxyethylmethacrylate, and a photopolymerization catalyst to the plaster cast and briefly exposing said thin layer to light having a wavelength of 400-450 nm whereby said thin layer is partially polymerized, successively applying at least one additional thin layer on said first thin layer and partially polymerizing each successive thin layer by brief exposure to light having a wavelength of 400-450 nm until the layer thickness and shape desired for the device or appliance are attained, and the partially polymerized material is subsequently polymerized completely by exposure to light having a wavelength of 350 nm.