In vitro study of mean loads and modes of failure of all-ceramic crowns cemented with light-cured or dual-cured luting cement, after 1 and 30 d of storage

This study compared the mean loads and modes of failure of teeth restored with all-ceramic crowns (ACCs) cemented with dual-cured (RelyX ARC; 3M ESPE) or light-cured (RelyX Veneer; 3M ESPE) luting cements. Clinically, there are advantages of light-cured cements over the recommended dual-cured cements, namely increased working time, improved handling, colour stability, and a homogenous mix. Forty, sound, extracted, human, premolar teeth underwent a standardized preparation for ACCs. IPS Empress (Ivoclar-Vivadent) crowns of standard dimensions were fabricated and 20 were cemented with each cement. The crowns were stored for 1 or 30 d in water and subjected to a compressive load to failure at 0.017 mm s(-1). There were no significant differences in loads at failure, between each cement group, at each storage period, and there were no significant differences in loads at failure, for each cement, at 1 and 30 d of storage. There were also no significant differences in modes of failure between each cement group. Before recommending light-cured cement as an alternative to dual-cured cement for the cementation of all-ceramic crowns, further research is required to establish the depth of ceramic at which light-cured lutes fail to polymerize completely.