Full porcelain restorations, also known as Empress crowns, are used today as the most aesthetic crowns; because the whole structure of the crowns are made of porcelain, including the frameworks.

The outer layer of the teeth is called as enamel and dentin layer is located beneath enamel layer. In the application of full porcelain crowns, reinforced porcelain cores used as frameworks mimic dentin and the porcelain layer over the core imitates enamel. Hence, high light transmittance and natural colors are achieved.

Due to absence of metal alloy frameworks, full porcelain crowns are highly biocompatible with gingival tissues and suitable for patients with metal allergies.

Full porcelain crowns are preferred where aesthetics is important for frontal teeth, premolars and bridges with single tooth gaps in this area.

Like laminate veneers, the application of full porcelain crowns is more appropriate after eliminating clenching / grinding and bad habits (i.e. nail biting). 

These crowns are called zirconia crows as they are applied by using zirconia framework in tooth colour rather than conventional gray metal alloy framework and porcelain is used over the zirconia framework. For this reason, zirconia frameworks do not reflect grayish colours of conventional gray metal alloy frameworks.

Zirconia material is highly biocompatible with gingival tissues and does not cause allergic reactions. Also, these frameworks do not lead grayish reflections in the crown-gingival margins, which contributes to aesthetics.

Zirconia material has high durability and with this property, the crowns can be fabricated not only for frontal teeth, also for back teeth areas where  chewing forces increase. However, the bridges more than three crowns may increase the risk of breakage. 

Zirconia crowns can be prepared compatible with natural tooth color. Thus, high aesthetic appearance is obtained.