Additive manufacturing method and apparatus for the production of dental crowns and other objects

An additive manufacturing apparatus, comprising:

• a chamber having a planar circumferential top edge portion defining a chamber orifice;
• a stage movably positioned in said chamber, said stage having a planar top surface portion alignable with said chamber planar circumferential edge portion, the two together configured to receive a viscous resin;
• a dispenser facing said stage and operatively associated therewith, said dispenser configured to apply a planar coating of viscous resin to said stage planar top surface portion;
• a primary drive operatively associated with said dispenser and said chamber, said primary drive configured to move said dispenser across said chamber orifice;
• a light engine facing said stage and operatively associated therewith, said light engine configured to expose a coating of resin on said stage planar top surface to patterned light;
• and
• a stage drive operatively associated with said stage and configured to retract said stage into said chamber, following exposure of a coating of resin on said stage to patterned light;
• a resin reservoir;
• an applicator roller operatively associated with said reservoir;
• and
• a roller drive operatively associated with said applicator roller, wherein said applicator roller and roller drive are configured to be reversible between:
• (i) a first direction in which resin is pumped from said reservoir onto said stage;
• and
• (ii) a second direction in which excess resin is pumped from said stage into said reservoir while said dispenser moves across said chamber orifice to provide a smooth planar coating of said resin on said stage for subsequent exposure to patterned light, wherein said light engine is positioned above said stage, and wherein said chamber is fixed and stationary.