silica (SiO2) /sil′i·kə/ [L, silex, flint] , silicon dioxide, an inorganic compound occurring in nature as agate, sand, amethyst, flint, quartz, and other stones. It is one of the major constituents of dental porcelain and a common filler in resin composites. In granular form, it serves as a dental abrasive and polishing agent. See also silicosis.
