Before the advent of pressing technology ceramic restorations were most commonly produced using a process of combining liquid and powder into a slurry and then stacking this porcelain on the die. The ceramic is applied this way in layers and then fired. This process is still commonly used today and understanding the properties can allow us to use it to our advantage to achieve the clinical results we are after. Ceramics fabricated in this way are typically feldspathic or leucite reinforced glass, and used primarily for anterior restorations. The fabrication process is challenging and time consuming and requires a skilled ceramist to create both the esthetic results and a precisely fitting restoration. An advantage of this type of ceramic restoration is the ability the technician has to layer material of varying color and opacity.
Restorations can be made as thin as .3mm and therefore tooth preparation can be very conservative when utilizing this material. The material can be utilized for both full and partial coverage restorations. Due to the inherent physical properties of the ceramic and the creation process, restorations made this way have a relatively low flexural strength of 60-110mpa. With this is mind these restorations whether full or partial coverage must be bonded to the tooth for strength and durability using a etching/adhesive process. The intaglio surface of the ceramic is etched with hydrofluoric acid and then porcelain conditioner is applied prior to the resin cement.