IADR Abstract Archives
Color Stability of Multi-layer Fast Fired Zirconia
Objectives: This project seeks to examine the effects of rapid firing on shade as well as additional firing cycles needed for staining and glazing.
Methods: Rectangular tiles 2.0±0.2 mm thick were sectioned from blocks of multicolor zirconia manufactured by Kuraray (Katana zirconia, A2 and NW shade) and Denstply–Sirona (inCoris Zirconia, F1 and F0.5 shade). The titles (n=10 for each shade type) were fired using a fast fire cycle (1540°C for 30 minutes, total 1 hour) in inFire HTC furnace and a regular cycle in Zyrcomat furnace serving as a control, (1530°C for 2 hours, total 6 hours). Two additional glazing cycles (850°C for 1 min, total 26 mins) were performed in a Programat CS furnace. Color and shade were measured after each firing cycle. Color was measured using a Ci7600 Spectrophotometer (X-Rite) and a VTIA Easyshade V clinical digital shade-taking device. Comparison of color differences by ANOVA and Tukey-Kramer HSD test (a = 0.05) was done using JMP Pro 13.2.
Results: The color changes after one glaze (ΔE*1) and two glaze (ΔE*2) cycles for each group are shown in Figure 1. Pooled data showed a color change after first glaze firing ΔE* was 0.661 ± 0.584 for inCoris Zirconia, and 0.931± 0.573 for Katana Multilayered Zirconia, while 0.875 ± 0.682 for regular firing, and 0.717 ± 0.418 for fast firing. Linear regression showed firing method, glaze time, and zirconia type shade had no significant effect on the color change.
Conclusions: Color change after glazing firing of zirconia sintered using fast firing showed no significant difference compared to that using regular firing. Glazing firing of multilayer zirconia had no significant color change compared to monochromatic zirconia.
Methods: Rectangular tiles 2.0±0.2 mm thick were sectioned from blocks of multicolor zirconia manufactured by Kuraray (Katana zirconia, A2 and NW shade) and Denstply–Sirona (inCoris Zirconia, F1 and F0.5 shade). The titles (n=10 for each shade type) were fired using a fast fire cycle (1540°C for 30 minutes, total 1 hour) in inFire HTC furnace and a regular cycle in Zyrcomat furnace serving as a control, (1530°C for 2 hours, total 6 hours). Two additional glazing cycles (850°C for 1 min, total 26 mins) were performed in a Programat CS furnace. Color and shade were measured after each firing cycle. Color was measured using a Ci7600 Spectrophotometer (X-Rite) and a VTIA Easyshade V clinical digital shade-taking device. Comparison of color differences by ANOVA and Tukey-Kramer HSD test (a = 0.05) was done using JMP Pro 13.2.
Results: The color changes after one glaze (ΔE*1) and two glaze (ΔE*2) cycles for each group are shown in Figure 1. Pooled data showed a color change after first glaze firing ΔE* was 0.661 ± 0.584 for inCoris Zirconia, and 0.931± 0.573 for Katana Multilayered Zirconia, while 0.875 ± 0.682 for regular firing, and 0.717 ± 0.418 for fast firing. Linear regression showed firing method, glaze time, and zirconia type shade had no significant effect on the color change.
Conclusions: Color change after glazing firing of zirconia sintered using fast firing showed no significant difference compared to that using regular firing. Glazing firing of multilayer zirconia had no significant color change compared to monochromatic zirconia.