A comparison of the microstructure and properties of the IPS Empress (R) 2and the IFS Empress (R) glass-ceramics

The aim of this report is to analyze the microstructures of glass-ceramics of the IPS Empress(R)2, and IPS Empress(R) systems by scanning electron mic roscopy. The main properties of the glass-ceramics were determined and comp ared to each other. The flexural strength of the pressed glass-ceramic (cor e material) was improved by a factor of more than three for IPS Empress(R)2 (lithium disilicate glass-ceramic) in comparison with IPS Empress(R) (leuc ite glass-ceramic). For the fracture toughness, the K-IC value was measured as 3.3 +/- 0.3 MPa . m(0.5) for IPS Empress(R)2 and 1.3 +/- 0.1 MPa . m(0. 5) for IPS Empress(R). Abrasion behavior, chemical durability, and optical properties such as translucency of all glass-ceramics fulfill the dental st andards. The authors concluded that IPS Empress(R)2 can be used to fabricat e 3-unit bridges up to the second premolar. (C) 2000 John Wiley & Sons, Inc .