Zirconia changes after grinding and regeneration firing

Abstract

Adjustments by grinding in 3Y-TZP frameworks should be performed with water cooling, and regeneration firing should be undertaken to obtain a more reliable material.

Fatigue behavior and surface characterization of a Y-TZP after laboratory grinding and regeneration firing

“…The null hypothesis was rejected, once water-cooling grinding increased the flexural fatigue limit of the Lava™ ceramic. Previous studies evaluating the monotonic flexural strength (Hatanaka et al, 2017) and flexural fatigue limit (Zucuni et al, 2017;Polli et al, 2016), after grinding with diamond burs specific for zirconia, also verified changes in the static and dynamic mechanical properties of Lava™ Y-TZP. These results were probably related to the compression stresses induced by t→ m phase transformation (Zucuni et al, 2017;Curtis et al, 2006;Karakoca and Yilmaz, 2009;Amaral et al, 2016;Pittayachawan et al, 2009) accompanied by volumetric expansion of approximately 5.0% (Kim et al, 2010;Denry and Holloway, 2006) that resulted in compressive stresses in the micrometric layers of the surface, which not only contained the surface failures (Khayat et al, 2018), but at first increased the fracture strength of the material (Pereira et al, 2016;Khayat et al, 2018;Hjerppe et al, 2016).…”

Preparation of a Novel Transplant Material, Zirconium Oxide (ZrO₂) Nanotubes, and Characterizations Research

“…Generally, there are three phases for Zr: tetragonal, monoclinic, and cubic [ 29 ]. The tetragonal and monoclinic phases are achieved at temperatures lower than 1000°C, and cubic phase is achieved at temperatures higher than 1000°C [ 30 ].…”

Effect of airborne particle abrasion and sintering order on the surface roughness and shear bond strength between Y-TZP ceramic and resin cement

“…Particularly, the high demand for esthetics in recent years has led to the development of all-ceramic restorations 2) . Dental ceramics with a high crystalline content, such as zirconia ceramics, are a popular core material for fixed restorations, due to their high fracture toughness 3,4) and chemical inertia 5,6) compared to other silica-based ceramics.…”

“…Zirconia has superior physical properties and high biocompatibility, which has attracted clinical research investigations and led to its applications as a framework for crowns and fixed partial dentures [7][8][9][10] . Zirconia has three different crystallographic phases: at room temperature, pure zirconia exists as a monoclinic crystal structure while it transforms to a tetragonal structure at 1,170°C and cubic structure at 2,370°C 6,11,12) . When zirconia is cooled down, a tetragonal-monoclinic transformation occurs 6) , and the zirconia expands 3 to 5% in volume [11][12][13] , creating stresses in the material that may cause cracks 14,15) .…”

“…Zirconia has three different crystallographic phases: at room temperature, pure zirconia exists as a monoclinic crystal structure while it transforms to a tetragonal structure at 1,170°C and cubic structure at 2,370°C 6,11,12) . When zirconia is cooled down, a tetragonal-monoclinic transformation occurs 6) , and the zirconia expands 3 to 5% in volume [11][12][13] , creating stresses in the material that may cause cracks 14,15) . In dental applications, zirconia is usually stabilized by the addition of 3 mol% yttrium oxide, which ensures its tetragonal crystalline phase at room temperature 15,16) .…”