The relationship between cure depth and transmission coefficient of visible-light-activated resin composites.

The relationships between the transmission coefficient and the cure depth were evaluated on eight commercially available light-activated resin composites. The determination of transmission coefficient was carried out by the use of a radiometer for various shades of the resin composites. The transmission coefficient, ranging from 0.042 to 0.263, was dependent upon the shade of the resin. There was a good correlation between the transmission coefficient and the cure depth for different shades for each resin composite, except for one hybrid resin composite (P-50). The microfilled resin composite showed transmission coefficient and cure depth lower than those of the hybrid and small-particle-filled resin composites.