Fig. 4From: Efficiency of tooth bleaching agent on staining and discoloration characteristics of nicotine stained dental enamel modelRepresentative whiteness enhancements from tooth bleaching formulae set #2 (L1.0 + CD20) on the stained dental enamel model. L, CD, and CP represented limonene, coconut diethanolamide, and carbamide peroxide, respectively (p < 0.05)Back to article page