The effect of coffee solution on tooth color during home bleaching applications

Purpose: To quantify the change in color of human and bovine teeth exposed to a coffee solution during a 16% carbamide peroxide (16%CP) home application bleaching treatment using photoreflectance analysis. Methods: 40 enamel slabs (4x4x2 mm) were obtained from seven unerupted third human molars and seven bovine incisors, which were allocated into four groups: G1: human control group whitened and not exposed to a coffee solution; G2: bovine control group whitened and not exposed to a coffee solution; G3: human teeth whitened and exposed to a coffee solution; G4: bovine teeth whitened and exposed to a coffee solution. The home bleaching procedure was performed using 16%CP gel applied in a I mm-thick layer on the tooth surface over a period of 6 hours per day, for 28 days. Tooth color was evaluated using photoreflectance analysis throughout the bleaching procedure at intervals of 7, 14, 21 and 28 days, and post-treatment at 7, 15 and 30 days. Results were statistically analyzed using ANOVA and Tukey-Kramer tests. Results: After 28 days of bleaching treatment, no significant difference was detected between photoreflectance analysis of specimens exposed to coffee solution and specimens not exposed to coffee solution (P< 0.05). However, when the teeth were exposed to a coffee solution during home bleaching treatment, the whitening effect was observed to be less stable (P< 0.05). Bovine and human enamel substrates behaved similarly in terms of staining and bleaching effects, although they presented inherent differences in color (P< 0.05). (Am J Dent 2009;22:175-179).22317517