Detail the names of the different layers of porcelain used in the process of building a standard anterior PFM crown after the first layer, and give descriptions of their functions.

Detail the names of the different layers of porcelain used in the process of building a standard anterior PFM crown after the first layer, and give descriptions of their functions.

1. • CORE PORCELAIN: the base or core of a PJC (no metal substructure). It has good mechanical properties as it this section of the crown that supplies the strength of the final item.

2. • OPAQUE PORCELAIN: in metal-bonding porcelains, this porcelain powder is used for two reasons: To bond the porcelain veneer to the metal substructure and to mask out the dark colour of the metal substructure

3. • DENTINE PORCELAIN: more translucent than the core and opaque powders and largely governs the shape and shade of the restoration. The dentine layer of a restoration will contain the largest bulk of porcelain. It may be supplied in more than 1 powder to aid the technician in matching the patient’s dentition.

4. • ENAMEL PORCELAIN: this is a quite translucent powder and it forms the incisal/occlusal portion of the crown.

5. • STAIN and GLAZE PORCELAIN: these porcelains are air-fired (without vacuum) to aid the production of a highly glazed surface. Glaze porcelains are clear in colour, while stains are darkly pigmented and used to characterize the final restoration.

6. • Most modern porcelain systems have a wide range of specific coloured powders that do not fall under these headings, and may be incorporated within these layers to produce more lifelike and custom restorations.

7. Opaque Porcelain

8. Dentine Porcelain

9. Enamel Porcelain

10. Stain and Glaze porcelain

11. Core Porcelain