Role of 3Y-TZP grain boundaries in glazing and layering

• Published in: Dental materials 2024-12, Vol.40 (12), p.2148-2156
• Main Authors: Shahmiri, R., Standard, O.C., Hart, J.N., Gharagozlu, N., Bahmanrokh, G., Yin, Y., Mofarah, S.S., Adabifiroozjaei, E., Webster, R., Sorrell, C.C.
• Format: Article
• Language: English
• Subjects: 3Y-TZP; Dental Materials - chemistry; Ferroelastic domain switching toughening; Glazing; Grain boundaries; Hot Temperature; Layering; Materials Testing; Sintering; Surface Properties; Vacuum; Yttrium - chemistry; Zirconium - chemistry
• ISSN: 0109-5641; 1879-0097; 1879-0097
• DOI: 10.1016/j.dental.2024.10.005

Monolithic 3 mol% Yttria-stabilized tetragonal zirconia polycrystal or 3Y-TZP exhibits transformation toughening phenomena which is suitable for dental restorations with minimizing the risk of fracture and to decrease reduction of natural tooth. However, the staining/glazing or layering is required to achieve of a match with the optical properties of natural dentition. The hypothesis under examination is that the physical, chemical, and structural aspects of the 3Y-TZP grain boundaries after the staining/glazing or layering. The three sintering temperatures of 1400 °C, 1500 °C, and 1600 °C were considered followed by vacuum annealed at 750 °C for 1 min; and air post-annealed at 750 °C for 1 min The initial sintering step in the fabrication of zirconia restorations plays a critical role in the outcomes of the subsequent stages of glazing and layering. The current study revealed for first time the advantage of vacuum annealing by the presence of ferroelastic domain switching toughening mechanism.