STUDIES ON THERMAL-STABILITY OF MODIFIED POLYCARBOXYLATE CEMENTS

Dental cement compositions made by mixing poly(acrylic acid-co-acrylam ide) and mixtures of zinc oxide and cryolite (Na3AlF6) in various prop ortions of 10-50 wt.-% (w/w) were cured at room temperature. From ther mogravimetric analyses of the samples, the integral procedural decompo sition temperatures (IPDT), maximum decomposition temperatures, activa tion energies and frequency factors were evaluated. The cured cement s ample containing 20 wt.-% cryolite in the filler mixture is thermally very stable.