Thermal properties of glass ionomer cement

Five currently available glass ionomer cements (BASE CEMENT, DENTIN CEMENT, HY-BOND GLAS IONOMER-F, KETAC CEM, TOKUSO IONOMER) were studied with regard to the relationship between thermal properties and powder-liquid ratio (P/L ratio). The experiments were performed using five different P/L ratio of 0.8, 0.9, 1.0, 1.1 and 1.2 (P/L = 1.0: manufacturer's instruction) and measured with a xenon flash thermal-constant measuring device. Thermal diffusivity of the glass ionomer cements ranged from 0.212 to 0.303 x 10(-2) cm2 s-1; it increased according to the increase in the P/L ratio. The specific thermal capacity of the glass ionomer cements ranged from 1.011 to 1.369 Jg-1 K-1; it decreased with the increase in the P/L ratio. Thermal conductivity of the glass ionomer cements ranged from 0.505 to 0.712 Wm-1 K-1; it increased according to the increase in the P/L ratio.