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 < .001). Grains became significantly larger and pores were present when two of the zirconia materials (Prettau Anterior and Zpex Smile) were sintered with a high-speed sintering program.


CONCLUSIONS
Two of the zirconia materials (Prettau Anterior and Zpex Smile) became less translucent and less strong using a high-speed sintering program, whereas another (Katana STML Block) was unaffected.
['Lawson|Nathaniel C|NC|https://orcid.org/0000-0001-9684-2015', 'Maharishi|Anvita|A|']
D002516:Ceramics D003764:Dental Materials D003776:Dental Porcelain D008422:Materials Testing D013499:Surface Properties D015040:Zirconium
zirconia CAD/CAM lithium disilicate ceramic digital dentistry