A laboratory study was conducted to determine the effectiveness of plastic wedges used in conjunction with visible light for polymerization of restorative resin. Two commercially available wedge systems were evaluated in this study: 1) a clear plastic wedge with a light reflecting core, and 2) a clear plastic wedge without a reflecting core. Polymerization was evaluated by testing the hardness of the composite resin specimen that was placed adjacent to the wedge surface. Significant differences in hardness were found between composite samples cured directly, those cured with a clear wedge (no reflecting core), and those cured with a wedge having a reflecting core.