[Research progress on low-temperature degradation of zirconia and its effect on the optical properties of high-transparency zirconia].

High-translucency zirconia (4Y/5Y-TZP) is widely used in dental prosthetics due to its excellent aesthetic property. However, it is susceptible to low-temperature degradation (LTD) in the oral environment, leading to deterioration of mechanical and optical properties. This article systematically reviews the mechanisms, influencing factors, and in vitro simulation protocols of LTD, with a focus on its impact on the optical properties of high-translucency zirconia. Existing studies indicate that enhanced light scattering, which is the result of phase transformation, surface roughening, and microcracks induced by LTD, is the primary cause of optical degradation. Nevertheless, conflicting findings exist regarding in the influences of LTD on translucency and color difference. To optimize the esthetic properties of high-translucency zirconia, future efforts can be devoted to establish a standardized multi-factor coupled aging evaluation system and explore the relationship between the spatial distribution of phase transformation and optical degradation.