Zirconia sintered body

A columnar zirconia sintered body suitable for making a dental restoration, the sintered body comprising:

• a base extending in an xy-plane having an x-axis for length and a y-axis for width;
• and
• a plurality of side faces extending orthogonally from the base along a z-axis as a height formed around a perimeter of the base, the plurality of side faces each having identical height:
• wherein the base comprises a main body portion and a stem portion,
• wherein the base has a surface shape, seen from a bottom and/or top plan view along the z-axis, that is neither square nor rectangular, but comprises a straight portion,
• wherein the surface shape comprises (i) a combination of a rectangle and a curved portion of the base extending along the x-axis in the xy-plane, or (ii) a first receding portion and a second receding portion defining a narrow portion, the main body portion being in contact with the narrow portion, the stem portion comprising the narrow portion, the stem portion having a smaller area than the main body portion at a region contacting the main body portion,
• wherein the main body portion and the stem portion, and the narrow portion in (ii) between the main body portion and stem portion, are comprised by the base,
• wherein the stem portion is as high as the main body portion in height across an entire length along the z-axis from the main body portion to an end of the stem portion,
• wherein the first and second receding portions in (ii) have a shape defined by recessed portions extending along the side faces along the z-axis, and
• wherein the stem portion has a minimum width, in the y-axis, of more than 4 mm.