IADR Abstract Archives
Effect of Changes in Sintering Parameters on Zirconia's Grain Size
Objectives: To evaluate the effect of sintering time and temperature on the grain size of various translucent zirconia.
Methods: One gram of commercial TOSOH Y-TZP powders, Zpex and Zpex Smile were uniaxial dry-pressed in a hardened steel die set of 5/8-inch (15.88 mm) internal diameter mold with a load of 3,000 Newtons, yielding 1.3 mm thickness discs (N=120). They were presintered using either a short or a long duration to 1000°C and then sintered at different final temperatures(1300 °C, 1450 °C, 1600 °C) using high temperature furnace (Zircar Hotspot 110L). Scanning electron microscopic (SEM) micrographs were taken on each specimen under 20k magnification. Grain size was measured on SEM micrographs using ImageJ software according to the ASTM standard E112. At least 200 grains were analyzed for each specimen.
Data was analyzed by JMP Pro 13 using multifactorial linear regression and ANOVA post hoc Tukey HSD test. The effects of different factors and differences between groups were compared. The P-values less than 0.05 were considered statistically significant.
Results: The grain size of tested zirconia sintered under different conditions is compared in Figure 1.
Conclusions: The grain size of Zpex Smile discs was significantly greater than Zpex discs. The final sintering temperature, zirconia powder type, and their interaction have significant effects on the grain size, while there is no significant effect on the grain size by different presintering cycles. Higher final sintering temperature produces larger grain size.
Methods: One gram of commercial TOSOH Y-TZP powders, Zpex and Zpex Smile were uniaxial dry-pressed in a hardened steel die set of 5/8-inch (15.88 mm) internal diameter mold with a load of 3,000 Newtons, yielding 1.3 mm thickness discs (N=120). They were presintered using either a short or a long duration to 1000°C and then sintered at different final temperatures(1300 °C, 1450 °C, 1600 °C) using high temperature furnace (Zircar Hotspot 110L). Scanning electron microscopic (SEM) micrographs were taken on each specimen under 20k magnification. Grain size was measured on SEM micrographs using ImageJ software according to the ASTM standard E112. At least 200 grains were analyzed for each specimen.
Data was analyzed by JMP Pro 13 using multifactorial linear regression and ANOVA post hoc Tukey HSD test. The effects of different factors and differences between groups were compared. The P-values less than 0.05 were considered statistically significant.
Results: The grain size of tested zirconia sintered under different conditions is compared in Figure 1.
Conclusions: The grain size of Zpex Smile discs was significantly greater than Zpex discs. The final sintering temperature, zirconia powder type, and their interaction have significant effects on the grain size, while there is no significant effect on the grain size by different presintering cycles. Higher final sintering temperature produces larger grain size.
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