TOSOH is a manufacturer of patented all-natural zirconia nano-powder – the highest quality zirconia in the world.
The company does not allow their logo to be used in association with any product that is not made 100% of TOSOH and that does not comply to their strict quality policy. ZICERAM is one of the few CAD/CAM disc manufacturers that have been granted the right to use the official logo.
ZICERAM® Zirconia products are always made 100% from Japanese TOSOH yttria-stabilized nano zirconia powder – and the products have TOSOH’s official seal of quality.
When examined with a metallographic microscope, TOSOH zirconia powder shows perfect granular homogeneity when compared to competitors.
This uniformity ensures that ZICERAM® products’ fracture probability is the lowest on the market and the strength and aging factors are unmatched compared to competitors.
Metallographic microscope images reveal that TOSOH micro structure is homogenous unlike that of poor quality zirconia. The pictures also reveal inconsistencies and impurities in the low-quality and cheap Chinese zirconia (C-1 & C-2).
When examined with a metallographic microscope, each particle of TOSOH nano-zirconia is perfectly smooth compared to low-quality Chinese counterparts. Smoothness has an effect on how tightly the particles hold on to each other when pressed together, and therefore affects strength and fracture probability.
Strength can be measured by 3-point and a 4-point test. The difference is that 4-point test uses a larger surface area, which increases the likelihood of there being a small pore in the tested area. The majority of manufacturers use 3-point tests because they show more favorable results. They usually also display average values to hide inconsistencies. ZICERAM® Zirconia strength values are always based on 4-point testing and minimal strength values of the products are presented.
When 3-point tested, C-1 (Chinese zirconia) looks good. However, minimum flexural strength data should be considered, not just the maximum.
TOSOH 3-point test mean strength value is higher than the maximum strength values of competitors.
3-point test values for the second best Japanese nano-zirconia (J-1) look good but the low values of 4-point testing look very different. This shows clearly the effect of test method.
TOSOH test values on 4-point tests keep the high strength values unlike the competitors.
Fracture probability is a key element as it shows what are the chances of a failure of a construction made from the material. TOSOH has the lowest chance of failure on the market.
Some competitors appear to have a good crush performance, especially in top of the graph. However, the lower part of the graph makes all the difference.
For example, at 0.5 kgf, Competitor F (2nd leading Japanese Zirconia) has about 20% probability to break – but TOSOH has 0% probability to break at 0.5 kgf.
Crush probability ball test is performed by applying pressure on a single point
Powder characteristics that are essential for making high quality dental discs:
Lot-to-Lot consistency makes sure that all products made of the material exhibit same features and same technical properties. This ensures consistent quality in every unit.
Purity makes sure that the material is strong due to no foreign bodies being present and also that it is healthy, with no negative elements that could affect a patient’s health.
|TOSOH||ZrO₂+HfO₂+Y₂O₃+Al₂O₃ > 99.9%|
|C-4 Company||Mg, Si, S, Cr, Cu, Zn, Sn, Pb, CaCO₃, Talc, Mica|
Chemical analysis shows the purity and consistency of TOSOH nano-zirconia. Poor quality brands can have strange contaminations elements and/or additives in their zirconia. Even led has been found in poor-quality products.
Transformation of aging shows how constructions lose their strength when used.
When tested in hot water, TOSOH material does not show any signs of aging.
|Disc-1 (COO USA)||11||2|
|Disc-2 (COO China)||22||10|
|Zpex Smile (TOSOH)||0||0|
Discs made of TOSOH zirconia have minimal to no aging.
Patients using the final product don’t have to be afraid to consume hot and cold drinks as these will not damage their dental construction.