Biaxial flexural strength and translucent characteristics of dental lithium disilicate glass ceramics with different translucencies

PURPOSE: The aim of this study was to evaluate the biaxial flexural strength and translucent characteristics of dental lithium disilicate glass ceramics with different translucencies. METHODS: Two heat pressed lithium disilicate glass ceramics (IPS e.max Press and an experimental ceramic) and one computer aided design/ computer aided manufacture (CAD/CAM) lithium disilicate glass ceramic (IPS e.max CAD) with different translucencies were evaluated. Disk-shaped specimens of each group were subjected to a biaxial flexural strength (BFS) test. Translucent parameters (TP) were also tested at 0.5 mm and 1.0 mm thickness, respectively. X-ray diffraction (XRD) and SEM were used for crystalline and microstructural analysis. RESULTS: BFS values of two heat pressed lithium disilicate glass ceramics were significantly higher than the CAD/CAM counterpart. No difference in BFS between two heat pressed glass ceramic was found. There were significant differences in BFS and TP values among the tested subgroups with different translucencies for IPS e.max Press and IPS e.max CAD. No difference in crystalline composition was found among the tested glass ceramics, but microstructure with shorter and wider crystal was revealed for IPS e.max CAD ceramics. CONCLUSIONS: Lithium disilicate glass ceramics with different translucencies demonstrated different BFS and TP values.