Aluminosilicate glasses calcium-containing

In a study of dental silicate cements, Kent, Fletcher Wilson (1970) used electron probe analysis to study the fully set material. Their method of sample preparation varied slightly from the general one described above, in that they embedded their set cement in epoxy resin, polished the surface to flatness, and then coated it with a 2-nm carbon layer to provide electrical conductivity. They analysed the various areas of the cement for calcium, silicon, aluminium and phosphorus, and found that the cement comprised a matrix containing phosphorus, aluminium and calcium, but not silicon. The aluminosilicate glass was assumed to develop into a gel which was relatively depleted in calcium. 

Cestari A, Bandeira LC, Calefi PS, Nassar EJ, Ciuffi KJ. Preparation of calcium fluoro-aluminosilicate glasses containing sodium and phosphorus by the nonhydrolytic sol-gel method. J Alloys Compd 2009 472(l) 299-306. 

---