ZIRCONIA DISCS & BLOCKS

Dental zirconia discs are pre-sintered discs made of zirconium dioxide (ZrO2) that are used in the fabrication of dental restorations such as crowns, bridges, and implant abutments. These discs are milled into the desired restoration shape using Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) systems and then sintered in a furnace to achieve their final hardness and translucency.

Dental zirconia discs and their applications:

1. Types of Zirconia: There are various types of zirconia used in dentistry based on their aesthetic and strength characteristics. The most common types include:

   • High-translucency zirconia (HT): Used for anterior restorations due to their superior aesthetics.
   • High-strength zirconia: Typically used for posterior restorations because of their durability.
   • Multilayer zirconia: These discs have varying layers of translucency and color, mimicking the natural gradation of teeth.

2. Milling Process: The zirconia disc is placed into a CAD/CAM milling machine. The design of the dental restoration is digitally sent to the machine, which then precisely mills the restoration out of the disc.

3. Sintering: After milling, the zirconia restoration is "green" or in a softer state. It's then placed into a sintering furnace where it's heated to very high temperatures. This process densifies the zirconia and gives it its final strength and translucency.

4. Characteristics:

   • Strength: Zirconia is one of the strongest ceramic materials used in dentistry, making it ideal for restorations that require durability.
   • Biocompatibility: Zirconia is biocompatible, meaning it's well-tolerated by the human body and doesn't cause allergic reactions.
   • Aesthetics: Modern zirconia materials offer a balance of strength and aesthetics, making them suitable for both anterior and posterior restorations.

5. Applications: Dental zirconia is used for various applications like:

   • Single crowns
   • Bridges
   • Implant abutments
   • Inlays and onlays

6. Advantages:

   • Durability: Zirconia restorations have a long lifespan and are resistant to wear and fractures.
   • Aesthetics: With advancements in dental ceramics, zirconia can be made to closely match the appearance of natural teeth.
   • Metal-free: For patients who want metal-free restorations or have allergies to certain metals, zirconia is an excellent alternative.