Zirconia: More and More Translucent

Abstract

Purpose of ReviewYttria-stabilized zirconium dioxide, 3 mol% Y-TZP (zirconia, 3Y-TZP) was introduced as a prosthetic material to provide metal-free, tooth-colored, and durable material option for the patients. However, its optical properties are not ideal. This review describes the different strategies to increase translucency of zirconia material and summarizes the current knowledge of translucent zirconia for fixed prosthodontic applications.Recent FindingsOne of the most common ways of increasing the translucency of zirconia is to add the cubic phase by increasing Y2O3 content. Y2O3 4Y mol% and Y2O3 5Y mol% partially stabilized zirconia materials seem to have better optical properties compared to 3Y-TZP materials but with less favorable mechanical properties.SummaryDespite the attempts to develop a translucent zirconia material, its optical properties are still far from those of natural tooth structures. Possible solution for achieving more translucent and durable zirconia material could be utilizing nanocrystalline zirconia. The production of nanocrystalline zirconia is yet very technique-sensitive, and the sintering process needs to be well controlled. Additional research in this field is needed before recommendation for clinical use. In the future, the challenge will be in achieving balance between improved translucency without sacrificing from mechanical properties. This would apply not only for subtractive but also additively manufactured zirconia ceramics.