Effects of Different Porcelains and Shades on Light Transmission and Resin Polymerization.

This study evaluated the effect of light-curing through two ceramics on the degree of conversion-(DC) and Knoop microhardness-(KHN) of resin cements. Three shades were used and light-cured directly on a Golden Gate attenuated total reflectance FT-IR plate at 30°C. KHN was tested immediately and after 24-h. Resin shade, type of ceramic, and storage time all had significant effects on the DC and KHN values. Within each shade, the choice of ceramic always had a significant effect, but the shade of the resin had a greater effect. There was an increase in KHN of all cements after 24-h of storage.