Effect of multiple firings on mechanical and optical properties of CAD/CAM lithium disilicate-based glass ceramics

There was no apparent impact on biaxial flexural strength and microhardness of CAD/CAM lithium disilicate-based glass ceramics after multiple firings. However, multiple firings affected the color stability and shear bond strength of lithium disilicate-based glass ceramics. The color change was noticeable after the third firing cycle, specifically CEREC Tessera. The shear bond strength of LiSi CAD increased as a function of multiple firings. Cautiously corrective adjustments and recontouring are required to minimize the unessential firings.