Discoloration of composite resins can be induced internally or externally. In visible light-cured composite resin system, camphorquinone is generally used as the photoinitiator. However, if curing is inadequate, unconverted camphorquinone will cause a yellowish discoloration. Further, other components of the photoinitiator system - namely tertiary aromatic or aliphatic amines which act as so-called synergists or accelerators, they also tend to cause yellow or brown discoloration under the influence of light or heat4). These are internally induced discolorations which are permanent and which are related to polymer quality, filler type and amount, as well as the synergist added to the photoinitiator system 5-7). As dental practitioners cannot interfere in nor meddle with the content of composite resins, internal discoloration depends on the manufacturer’s formulations, except due to improper light curing.