Effect of Bleaching Agents on Composite Resins with and without Bis-GMA: An In Vitro Study.

The objective was to evaluate the change in color, hardness, and roughness produced by carbamide peroxide (CP) at two different concentrations on two resins. The 16% or 45% CP was applied to 66 resin discs with and without Bis-GMA. The color was measured with a spectrophotometer, and ΔE and ΔE were calculated.