Hs. Cardash et al., THE EFFECT OF PORCELAIN COLOR ON THE HARDNESS OF LUTING COMPOSITE RESIN CEMENT, The Journal of prosthetic dentistry, 69(6), 1993, pp. 620-623
Visible light- and dual-curing composite resin luting cements were cur
ed under porcelain disks of different colors to examine the effect of
porcelain color on surface hardness. Knoop microhardness measurements
were made at exposure times of 48, 72, and 120 seconds. Higher levels
of hardness were obtained with dual-cured resin. Visible light-cured r
esin irradiated through colored porcelain required more prolonged expo
sure times to reach a degree of hardness approaching that of dual-cure
resin. From the standpoint of microhardness, dual-cured composite res
in is preferred for luting porcelain restorations of greater-than-or-e
qual-to 2 mm thickness.