ST-ML Multi-Layer Zirconia Block , 1100MPa Strength , 16 Shades for Posterior Dental Crowns

ST-ML Multi-Layer Zirconia Block , 1100MPa Strength , 16 Shades for Posterior Dental Crowns

The ST-ML Multi-Layer Zirconia Block is China's most widely used pre-shaded zirconia solution, engineered specifically for high-strength posterior restorations. With 16 gradient shades (A1-D4) and 1100MPa flexural strength, it exceeds ISO 6872 Class 5 requirements for multi-unit bridges involving molar restoration. The material’s unique layered structure mimics natural dentin-enamel transitions, eliminating manual staining while maintaining 42% translucency for lifelike aesthetics in high-chewing-stress zones.

Key Characteristics

• Multi-Shade Efficiency: 16 pre-shaded options (A1, A2, A3, A3.5, A4, B1-B4, C1-C4, D2-D4) bypass coloring/drying steps (Page 14).

• Mechanical Superiority: 6.5 MPa·m¹ᐟ² fracture toughness prevents chipping under occlusal forces.

• Aging Resistance: <15% monoclinic phase after accelerated aging ensures long-term stability.

• Biocompatibility: 0-level cytotoxicity and <0.1 Bq/g radioactivity meet medical safety standards.

Technical Specifications

Clinical Applications
Optimized for posterior full-contour crowns and bridges (up to 4+ units), the ST-ML’s 1350 HV10 hardness withstands molar chewing forces. Its low thermal expansion (CTE: 10.5±0.5×10⁻⁶/K) minimizes sintering deformation, while the gradient shade layers provide:

• Natural Depth Effect: Seamless transition from cervical to incisal zones.

• Time Savings: Direct sintering after CAD/CAM milling (no staining).

• Cost Efficiency: Replaces metal-ceramic systems with 30% less tooth reduction.

Production Excellence
Fabricated via cold isostatic pressing (CIP) and nano-powder synthesis, each block ensures:

1. Uniform Density: 3.15±0.05 g/cm³ pre-sintered density.

2. Layer Precision: Gradient shading through controlled Y₂O₃ distribution (4.5-6.0%).

3. Impurity Control: <0.15% Al₂O₃ and <0.5% other oxides.

Advantages vs. Traditional Materials