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A: Hardness is a measure of a material’s ability to withstand impacting and abrasive forces, yet it also occupies a unique mechanical intersection between toughness and strength. Zirconia are extremely tough with outstanding impact resistance qualities. This denotes a balance between hardness, toughness, and strength which enables zirconia ceramics to withstand extremely high amounts of friction.

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A: Aconia® blanks are made by CIP( Cold Isostatic Pressing) processing technology. Cold isostatic pressing is the most accepted procedural technique for shaping Y-TZP and produces stable, chalk-like non-sintered green-stage objects with a very high primary density. Aconia® blanks have the proper density. High-density blanks are easily damaging the burs during the milling. Insufficient density blanks will cause margin chipping in a higher percentage.

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A: Fracture toughness is used to describe an ability of a material with a crack in it to resist further fracture. The higher fracture toughness of zirconia, the lower probability of the crack spreading in restorations. So the high value of fracture toughness ensures superior clinical long-term performance, which means the restorations can be long-term lasting. That is why fracture toughness is a clinically significant value. Aconia® HT plus has fracture toughness more than 9 MPa · m1/2. This highlight has helped more and more technicians to achieve more success in their work.

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For the dental zirconia, high flexural strength means wider indications, so it can be used to make restorations with more units. On the other hand, high flexural strength also affects the thickness of the restoration walls. A high-strength material allows a low wall thickness. Aconia® provides a wide range of zirconia blanks with different flexural strength, which means you can select the best solution for balancing aesthetics and strength.

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Flexural strength is a term that is frequently used in dental zirconia products, and it has been considered as a key feature of the stability of the material. In general, flexural strength indicates the resistance of a material against deformation. The commonly used flexural strength testing method is a 3-point testing method & 4-point testing method. The values measured from different testing method are not comparable. All Aconia® zirconia applies with the 3-point testing method.

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Crystal phases are used to describe the crystalline structure of substance under different temperatures. ZrO2 has three crystal phases: monoclinic, tetragonal and cubic. The monoclinic phase is stable at room temperatures up to 1170 ℃, the tetragonal at temperatures of 1170-2370 ℃ and the cubic at over 2370 ℃. About Aconia® zirconia, after sintered, the zirconia is mainly combined with tetragonal and cubic phases. The different percentage of crystal structures determines the different properties of sintered zirconia. 

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Yttria-stabilized zirconia (YSZ) is a zirconium oxide based ceramic, in which the particular crystal structure of zirconium oxide is made stable at room temperature by addition of yttrium oxide. The addition of yttria (Y2O3) as a stabilizing agent in zirconia allows the zirconia can be stable at room temperature with the tetragonal phase or the cubic phase. The different yttria (Y2O3) percentage in zirconia will lead to different ratio of tetragonal form and cubic forms in the final restoration, which come with the different strength and translucency of zirconia restorations. (eg. 3YSZ-with 3 mol-% Y2O3 partially Stabilized ZrO2, Yttria Stabilized Zirconia). Aconia® blanks are Yttria-stabilized zirconia.