Method of making a dental restoration by matching tooth color structure from an image of a tooth with block color structure of a restorative material

A method of making a dental restoration, comprising the steps of:

• capturing an image of a tooth at a color depth that is based on a multiplicity of color values;
• posterizing the image by:
• detecting in the tooth image a contiguous first tooth color area having color values within a predetermined first range of different color values and assigning the first tooth color area one common first false color value;
• and
• detecting in the tooth image a contiguous second tooth color area having color values within a predetermined second range of different color values and assigning the second tooth color area one common second false color value;
• determining a tooth color structure based on the first and second false color value of the first and second color area, respectively, within the tooth image;
• providing information about a multicolored block that has a predetermined color shading formed by at least a first block color zone and a second block color zone, wherein the information comprises data about a block color structure with respect to dimensions and/or positions of the first and second block color zone;
• matching the tooth color structure and the block color structure;
• and based on the matching;
• determining a position within the multicolored block in which the tooth color structure and the block color structure match within predetermined limits;
• and
• machining the dental restoration from the multicolored block at the determined position.