Strength and translucency of zirconia after high‐speed sintering

Objectives To compare the strength and translucency of CAD/CAM zirconia blocks, with traditional and high‐speed sintering, to lithium disilicate. Materials and Methods Three zirconia materials (Katana STML Block, Prettau Anterior, and Zpex Smile) were tested with either traditional (7 hours) or high‐speed (18 or 30 minutes in a SpeedFire furnace) sintering. A lithium disilicate material (IPS e.max CAD) was tested as a reference. Three‐point bend flexural strength specimens (16 mm × 4 mm × 1.2 mm, n = 10) were tested on 14‐mm‐separated supports and loaded to failure at 1 mm/min. Specimens (1 mm thick, n = 10) were measured in a Color‐i7 spectrophotometer against a black and white background to calculate translucency parameter. Zirconia specimens were thermally etched and a grain structure was observed with scanning electron microscopy. Data were analyzed with 1‐way ANOVA and Tukey's post hoc analysis (α = 0.05). Results There were significant differences between materials for flexural strength, translucency parameter, and grain size (P