Metal-free crowns

Non-metallic crowns (sometimes also called all-ceramic or full-ceramic) are a type of crown that does not use any type of metal in their fabrication. These crowns can be single units or connected into a bridge-like prosthesis. Essentially, plastic crowns (temporary) are also non-metallic.

What are crowns made of?

To manufacture permanent non-metallic crowns, the following materials are used:

• Feldspathic ceramic
• Hybrid ceramic
• Glass ceramic
• Lithium disilicate ceramic E.max
• Zirconium dioxide
• A combination of these materials

Single crowns can be made from any of the materials listed above. When making bridge constructions, zirconia is used as a high-strength framework material, onto which any type of ceramic can be applied, or the construction can be left fully zirconia but tinted with special dyes to give individual effects.

At the iStomatolog Center, all types of non-metal crowns are manufactured, but the E.max system from the German manufacturer Ivoclar Vivadent remains the undisputed leader. This system combines the properties of lithium disilicate and glass ceramics. Thanks to this, the crowns can withstand a load of 360-400 MPa (for comparison, metal ceramics - 70-80 MPa) without compromising aesthetic indicators. E.max material is predominantly used for single crowns, veneers, inlays, and overlays.

For bridge constructions, zirconia and its combination with ceramics are used. The strength of zirconia dioxide is 750-1050 MPa. The framework is milled from special blanks, and it is possible to cut out a full anatomical shape of the tooth or reduce the version onto which the ceramic mass is applied. Zirconia blanks come in different colors (matching the color of natural teeth), different degrees of transparency, and can also be multilayered with a gradation of color and transparency.

Advantages of metal-free ceramics

• Strength ranges from 350 MPa to 1050 MPa;
• Aesthetics due to translucency, similar to natural tooth tissue;
• Minimum thickness of 0.3 mm (compared to 1.5 mm for metal-ceramic crowns);
• Lightweight construction for bridges;
• The margin of the crown is placed above the gum line, reducing the risk of gum trauma and minimizing the likelihood of gingivitis or periodontitis;
• Veneers/lumineers can be made without tooth preparation (no drilling required);
• Ceramics and zirconia dioxide are biologically inert and compatible materials that do not cause allergic reactions (metal allergies are possible with metal-ceramic materials);
• Metal-free crowns are fixed with special composite materials, which further ensure the strength of the construction and preservation of the tooth under the crown.