คำอธิบาย
The first material developed for use as a direct esthetic restorative material was silicate cement. Introduced in the late 1800s, the cement was prepared from an alumina/silica glass and a phosphoric acid liquid. Highly soluble in oral fluids, silicate deteriorated rapidly, yet remained the favored material until the early 1950s. Dissolution, discoloration, loss of translucency and lack of adequate mechanical properties contributed to its eventual replacement.