Lithium disilicate as a dental restorative material

Glass ceramics are superior in aesthetics and biocompatibility. Traditional glass ceramics, such as feldspar and leucite glass ceramics, have been used for several decades as veneers, inlays, onlays and single crowns. Due to their strength limitations, they had high failure rates for load-bearing restorations. lithium disilicate glass ceramics (LDGC) have been developed for both pressing and CAD/CAM processes. COMPOSITION: They are derived from the SiO2–Li2O–Al2O3–K2O–ZrO2–P2O5 system through formation and solid state reaction LDGC consist of approximately 70% needle-like lithium disilicate(Li2Si2O5) crystals embedded in a glassy matrix containing disilicate and other oxides. There enforced lithium disilicate crystals have sizes of 3–6 μm in length and 0.5–0.8 μm in width, with interlocked and layered microstructures to strengthen LDGC