Progress of Toughness in Dental Zirconia Ceramics

Zirconia, attributable to high strength, toughness, hardness, and excellent wear resistance, as well as favorable biocompatibility, has been increasingly and widely applied to dental restoration. However, the phase transformation toughness of zirconia ceramics improves at the cost of service life deterioration. And zirconia ceramics may suffer failure and fracture after long-term mastication in the oral surroundings due to frequent changes in temperature and masticatory force, especially in the extremely complex biochemistry surroundings, such as fairly moist oral cavity and saliva. The research progress of zirconia ceramics in the field of dental restoration, toughening theories and their research state of dental ceramics were reviewed. This paper also summarized the issue of toughening degradation which is occurred in clinical application, and elucidated the mechanism and approaches. With the enhancement of comprehensive mechanical properties and the future demand for healthy functionalization, zirconia ceramics will be more widely applied in the biomedical field.