OBJECTIVETo evaluate the effect of the shade and thickenss of luting agent on the final color of different thickness Solidex resin in vitro.

METHODSFive specimens of Solidex resin were fabricated at thickness of 0.5, 1.0 and 1.5 mm. The pieces of Ni-Cr alloy, two shade composite resin and opaque porcelain veneered Ni-Cr alloy were used as backgrounds. The CIE L*a*b* values of specimens were measured by a colorimeter (ShadeEye NCC) to determine the colorimetric difference, when different thickness of specimens were overlaid the different shade and thickness of luting agent at the same backgrounds.

RESULTSThe final color difference of specimens was significantly influenced by the factors of luting agent and the interaction of specimens thickness, backgrounds and luting agent(P< 0.001). Regarding the thickness of luting agent, A3 shade luting agents produced clinically unacceptable difference (deltaE*>2) in the final color of Solidex specimens at the thickness of 0.5 mm. Regarding the shade of luting agent, the color difference was more than 2 when the Solidex specimens at the thickness of 0.5 mm or 1.0 mm were against the 0.2 mm thick luting agent.

CONCLUSIONThe final color of thinner Solidex specimens was significant affected by the change of the shade and thick of luting agent.