Ivory-colored zirconia sintered body, process for its production and its use

Abstract

An ivory-colored zirconia sintered body having high toughness, high mechanical strength and aesthetical excellence, a process for its production and its use as a bracket for orthodontic application; the sintered body containing stabilizer-containing ZrO.sub.2 as a main component, and also containing, based on the stabilizer-containing ZrO.sub.2, 0.05 to 1.0 mol % of Er.sub.2 O.sub.3, 0.0001 to 0.05 mol % of Pr.sub.6 O.sub.11, 0.0001 to 0.3 mol % of Fe.sub.2 O.sub.3 and 0.05 to 0.3 mol % of ZnO; the process comprising either (A) calcining a powder obtained from a solution containing a zirconium compound, a compound which becomes a stabilizer after calcination and sintering, an erbium compound and a praseodymium compound, adding and mixing an iron compound and a zinc compound to/with the calcined powder, forming a shaped body from the resultant mixture and sintering the shaped body, or (B) adding and mixing an erbium compound, a praseodymium compound, an iron compound and a zinc compound to/with a stabilizer-containing zirconia powder while the first two compounds are in a solution state, forming a shaped body from the resultant mixture, and sintering the shaped body; and the zirconia sintered body being used as a bracket for orthodontic application.

Dependencies are inferred from the claim text.