There are many advantages to using LD or Zirconia over PFM, but there are also many factors that might influence your choosing one material over another for your patients’ dental restorations. Each material has its own advantages and suggested uses. For example:
Strength: Zirconia has high flexural strength, up to 1400 mPa, and is kinder to opposing dentition than Type III Gold Alloy. Studies show that wear to the opposing dentition is not caused by material hardness but by surface abrasion or the “sandpaper effect”. When we process Zirconia, the surface is highly polished and glazed, making it very smooth. Zirconia is also more wear-resistant than gold, therefore retaining its original anatomical shape, and will not adversely effect the opposing dentition due to wear deformation from mastication of food or prolonged brushing. E.max Lithium Disilicate material, with a lower flexural strength of up to 500 mPa, is designed for maximum anterior esthetics and beauty.
Esthetics/Accuracy in Shade Matching: High-translucency e.max Lithium Disilicate is recommended where esthetics is paramount—for example, in cases where you need to exactly match the shade of a single anterior tooth. For overall smile designs, or other situations where individual teeth do not need critical shade-matching, most Dental Labs recommends Zotion Zirconia materials.
The advancement in the Zirconia allows for much better shade matching and no white spots like older zirconia products.
Thinness: Because Zirconia materials are so strong, they can be made thin—meaning that you can be more conservative in your preparation, saving more of patients’ original tooth structure. Zirconia may be as thin as ½ mm; the minimum thinness of e.max Lithium Disilicate materials is 1.5 mm to 2 mm.
Cementing Process: e.max Lithium Disilicate materials need to be etched and bonded to place, while Zirconia can be conventionally cemented, making the process easier.