In modern dentistry, the worldwide use of resin-based composites continues to increase, and in some countries has entirely replaced mercury amalgams. The use of direct polymer-based restorative materials has changed the way dentistry is performed and perceived. Initially, resin based composites were chemically activated, then, light- activated systems were introduced. The present project is aimed at describing different polymerization lamps and curing modes so that the clinician can efficiently use them for curing and curing should not be these five words for them "and then you light cure". A better understanding of this complex subject is essential to maximize the light output without suffering from any health hazard.