Methods of three-dimensional printing for fabricating a dental appliance

A method of fabricating at least one prosthetic denture base using a light-based three-dimensional printing apparatus, comprising the steps of:

• (a) preparing, in computer-aided design software, a virtual reference model of a prosthetic denture base, wherein the process of preparing a virtual reference model of a prosthetic denture base comprises the steps of:
• i. selecting a three-dimensional digital model of a prosthetic denture base, the three-dimensional digital model of a prosthetic denture base comprising a teeth-pockets facing side, a tissue facing side on the opposing side of the teeth-pockets facing side, and a denture border extending around the peripheral edge of the prosthetic denture base, forming a boundary between the teeth-pockets facing side and tissue facing side;
• ii. manipulating spatial orientation of the three-dimensional digital model of a prosthetic denture base to place the prosthetic denture base in a substantially horizontal position, wherein the teeth-pockets facing side is disposed either in an upward facing orientation or a downward facing orientation;
• iii. applying a minimum bounding box encompassing the three-dimensional digital model of a prosthetic denture base;
• iv. assigning a reference three-dimensional Cartesian coordinate (x-y-z) system to the three-dimensional digital model of a prosthetic denture base within the minimum bounding box, wherein the reference three-dimensional Cartesian coordinate system is aligned with the perimeter of the minimum bounding box, and further wherein an orienting reference plane is aligned with the base edge of the minimum bounding box;
• and
• v. removing the minimum bounding box;
• (b) preparing, in software of a computer system in operative control of a light-based three-dimensional printing apparatus, the virtual reference model and a three-dimensional digital model of at least one removable support structure for printing, wherein the process of preparing the virtual reference model and three-dimensional digital model of at least one removable support structure for printing comprises the steps of:
• i. positioning the virtual reference model adjacent to a virtual build platform surface provided by the software, wherein the tissue facing side of the virtual reference model is placed proximal to the virtual build platform surface;
• ii. manipulating spatial orientation of the virtual reference model, wherein the orienting reference plane of the virtual reference model is arranged at an inclination angle between about 65 degrees to about 80 degrees relative to the virtual build platform surface, with anterior teeth-pockets proximal to the virtual build platform surface and posterior teeth-pockets distal to the virtual build platform surface;
• and
• iii. generating a three-dimensional digital model of at least one removable support structure, connecting the virtual reference model to the virtual build platform surface;
• (c) providing a reservoir of liquid photopolymerizable composition in contact with a build platform surface of the light-based three-dimensional printing apparatus;
• (d) selecting, in software of the computer system in operative control of the light-based three-dimensional printing apparatus, printing process parameters to effectively photocure the liquid photopolymerizable composition in accordance with the virtual reference model and three-dimensional digital model of at least one removable support structure;
• and
• (e) instructing the light-based three-dimensional printing apparatus to print at least one prosthetic denture base and removable support structure from the liquid photopolymerizable composition.