Zirconia dental ceramics have become the first choice for dental clinical restoration due to their excellent mechanical properties, aesthetic properties and biocompatibility, and have been used as fixed partial dentures and dental implants. However, the performance of zirconia ceramics will deteriorate at low temperature in a humid environment, and the stability will be significantly reduced, which limits its wide clinical application. This paper introduces the deformation mechanism of t–m transformation of zirconia ceramics when low temperature deterioration occurs, and puts forward the methods to suppress the low temperature deterioration by focusing on improving the transformation free energy potential, preventing the dissipation of oxygen vacancies and adjusting the residual stress. The preparation process and its clinical application stability and evaluation results. Finally, the development prospects of zirconia dental ceramics are prospected.

Driven by the global aging population trend, the demand for dentures is increasing day by day. As a dental restoration material, it must first have good biocompatibility and not cause toxic side effects in the body. Secondly, as a supporting material, it should also have sufficient mechanical strength. In addition, with the improvement of people's aesthetic needs, the aesthetic effect of dental restoration has gradually attracted attention.

Porcelain teeth have been used as early as 1960. It is a ceramic veneer fired on a metal base to obtain a restoration with good aesthetic properties. However, as long as 3 years of clinical follow-up results show that the release of metal ions in porcelain teeth into the human body will cause allergic, local or systemic toxic reactions. The all-ceramic teeth developed in the past 30 years are metal-free restorations, and the crystallinity of ceramics is higher. The crystal phases usually include leucite, lithium disilicate, alumina, spinel, zirconia, and sanidine. Compared with the ceramic system, the all-ceramic system has better biocompatibility. However, due to the brittleness of alumina, it cannot be used for the repair of high load-bearing parts, which limits the scope of application. Subsequently, zirconia began to replace alumina and played an important role in the repair of damaged hard tissues due to its high toughness and excellent aesthetic repair properties (visible light transparency, X-ray opacity, etc.).

Zirconia ceramics, known as "ceramic steel", are regarded as an ideal substitute for traditional ceramic materials, and have been widely used as dental restoration materials, such as crowns, porcelain posts, piers, implants, etc. Due to the t-m phase transformation and toughening of zirconia, its mechanical properties are excellent in all-ceramic systems, with a strength of up to 840 MPa and a fracture toughness of 7.2 MPa m 1/2. However, in a humid environment, zirconia undergoes a spontaneous t–m transition, degrading the mechanical properties of the material. Such variable physical and chemical properties make it controversial and limit the scope of application. In recent years, a lot of research has been done on solving the problem of low temperature deterioration and improving the mechanical properties of zirconia dental ceramics in clinical applications.

This paper reviews the low-temperature deterioration of zirconia dental ceramics, emphatically explains the deformation mechanism and suppression methods, and summarizes the preparation technology and clinical application status of zirconia dental ceramics.