Table 1.
Firing chart for the porcelain used to veneering zirconia (VM9) and alloy (VM13) frameworks. Sintering and oxidation firing for zirconia and NiCr alloy frameworks, respectively.
| Material | Start temp. (°C) |
Predrying time (min) |
Heating time (min) |
Heating rate (°C/min) |
Final temp. (°C) |
Holding time for final temp. (min) |
Long- term cooling |
Vacuum holding time |
|
|---|---|---|---|---|---|---|---|---|---|
| VM9 | Base dentine Wash | 500 | 2 | 8.11 | 55 | 950 | 1 | - | 8.11 |
| 1° dentine firing | 500 | 6 | 7.27 | 55 | 910 | 1 | 600 | 7.27 | |
| 2° dentine firing | 500 | 6 | 7.16 | 55 | 900 | 1 | 600 | 7.16 | |
| Glaze firing | 500 | 0 | 5.00 | 80 | 900 | 1 | 600 | - | |
| Zirconia | -- | -- | -- | -- | 1450 | 120 | |||
| VM13 | Base dentine Wash | 500 | 2 | 5.52 | 75 | 940 | 2 | 5.52 | |
| 1° dentine firing | 500 | 6 | 6.55 | 55 | 880 | 1 | 6.55 | ||
| 2° dentine firing | 500 | 6 | 6.44 | 55 | 870 | 1 | 6.44 | ||
| Glaze firing | 500 | 0 | 4.45 | 80 | 880 | 2 | - | ||
| NiCr Alloy | Oxidation firing | 600 | 1 | 7.45 | 55 | 1010 | 10 | 17.45 | |