[Microstructure and mechanical property of a new IPS-Empress 2 dental glass-ceramic].
OBJECTIVE
To investigate the microstructure and mechanical properties of a new IPS-Empress 2 dental glass-ceramic.


METHODS
AFM, SEM and XRD were used to analyze the microstructure and crystal phase of IPS-Empress 2 glass-ceramic. The flexural strength and fracture toughness were tested using 3-point bending method and indentation method respectively.


RESULTS
IPS-Empress 2 glass-ceramic mainly consisted of lithium disilicate crystal, lithium phosphate and glass matrix, which formed a continuous interlocking structure. The crystal phases were not changed before and after hot-pressed treatment. AFM showed nucleating agent particles of different sizes distributed on the highly polished ceramic surface. The strength and fracture toughness were 300 MPa and 3.1 MPam(1/2).


CONCLUSIONS
The high strength and fracture toughness of IPS-Empress 2 glass ceramic are attributed to the fine lithium disilicate crystalline, interlocking microstructure and crack deflection.
Luo
Xiao-ping
XP
Department of Prosthodontics, Nanjing Stomatological Hospital, Nanjing 210008, China. L-xiaoping@yahoo.com
Watts
D C
DC
Wilson
N H F
NH
Silsons
N
N
Cheng
Ya-qin
YQ
D000538:Aluminum Silicates / Q000737:chemistry*; D019245:Compressive Strength; D003776:Dental Porcelain / Q000737:chemistry*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D013718:Tensile Strength; D014961:X-Ray Diffraction
D000538:Aluminum Silicates; C075815:IPS-Empress ceramic; D003776:Dental Porcelain