S. Uctasli et al., THE ATTENUATION OF RADIATION BY PORCELAIN AND ITS EFFECT ON POLYMERIZATION OF RESIN CEMENTS, Journal of oral rehabilitation, 21(5), 1994, pp. 565-575
The influence of porcelain thickness and opacity on the polymerization
of two dual activated (microfine and hybrid) and one light irradiated
(hybrid) resin cements was assessed by hardness measurements. The sur
face microhardness values of the upper and lower surface of 1 mm thick
resin cement specimens were determined. Specimens were polymerized us
ing 40 s irradiation beneath different thicknesses and opacities of po
rcelain discs. The results showed that increasing the thicknesses and
opacity of the porcelain produced a statistically significant decrease
in microhardness of the resin-based cements. The effect of attenuatio
n is less for the microfine cement than for the hybrids. In the case o
f hybrid cements, the light activated material performed better than t
he dual activated cement.