Ideal for crowns up to the second pre-molar, IPS Eris is comprised of an all-ceramic material fabricated from lithium disilicate crystals with a glass-ceramic overlay. The lithium disilicate glass-ceramic is extremely dense, adding strength and stability to spans for predictable results. The layering material contains a fluorapatite crystalline microstructure that enhances biocompatibility and supports the light dispersing properties similar to those found in natural tooth structure. Furthermore, the enhanced strength of the IPS Eris materials enables conventional cementation techniques (with glass ionomer cements) to be utilized when clinical conditions prohibit adhesive techniques.