A Method of Layerwise Building Up An Object And A 3D Printing Device For Performing Such A Method

A method of layerwise building up an object, preferably a dental restoration or dental restoration part, from at least a first and a second light hardenable resin on a 3D printing device, the 3D printing device comprising a build platform on which the object can be built up, a light-transmissive carrier comprising a plurality of recesses and a light projector that is arranged for projecting a light-pattern through the carrier toward the build platform, the method comprising the steps of:

• (a) partially building up the object and thereby providing an object-in-process;
• (b) coating a first surface area of the carrier with a first blank layer of the first light hardenable resin;
• (c) positioning the first blank layer between the build platform and the light projector;
• (d) advancing the build platform toward the carrier and thereby bringing the object-in-process into contact with the first blank layer;
• (e) irradiating the first blank layer with a light pattern to cause portions that are irradiated by the pattern to harden and thereby supplementing the object-in-process by a hardened layer;
• (f) retracting the build platform from the carrier and thereby separating the supplemented object-in-process from the carrier;
• (g) coating a second surface area of the carrier with e second blank layer of the second light hardenable resin;
• (h) positioning the second blank layer between the build platform and the light projector;
• (i) advancing the build platform towards the carrier and thereby bringing the object-in-process into contact with the second blank layer;
• (j) irradiating the second blank layer with a light pattern to cause portions that are irradiated by the platform to harden and thereby supplementing the object-in-process buy a further hardened layer;
• and
• (k) retracting the build platform from the carrier and thereby separating the supplemented object-in-process from the carrier.