Table 1.
Mechanical properties of IPS e.max press and GC Initial™ LiSi press materials.
| Properties (as provided by manufacturers) | Units | IPS e.max Press | Initial LiSi Press |
|---|---|---|---|
| Manufacturer | – | Ivoclar Vivadent | GC |
| Components | – |
lithium disilicate crystals (approx. 70%), Li2Si2O5, embedded in a glassy matrix |
lithium disilicate micro-crystals equally dispersed in a glass matrix |
| Crystal system | – | lithium disilicate - crystals measure 3 to 6 μm in length. | lithium disilicate - crystals measure 1.5 μm × 0.5 μm |
| Flexural Strength | MPa | 433* | 454* |
| Biaxial Flexural Strength | MPa | > 500 | > 500 |
| Vickers hardness | (HV10) 5900 ± 100 Mpa | 600 HV | |
| Chemical solubility | mg/cm2 | 40 ± 10 | 5.4 μg/cm2 |
| Liner thermal expansion CTE | × 10–6/K |
Coefficient of thermal expansion (100–400 °C) 10.15 ± 0.4 10− 6 K− 1 Coefficient of thermal expansion (100–500 °C) 10.55 ± 0.35 10− 6 K− 1 |
Liner thermal expansion CTE (25–500 °C) 9,8 × 10− 6 K− 1 |
| Glass transition temperature | °C | 560 | 520 |
| Density | g/cm3 | 2.5 ± 0.1 | 2,4 |
*Internal data, University of Siena.