Influence of tea and cola on tooth color after two in-office bleaching applications

Aim: To evaluate color changes of teeth after immersion in tea and cola following the application of two in-office bleaching products. Materials and Methods: A total of 60 specimens were obtained from 60 extracted sound human maxillary central teeth. The specimens were randomly divided into three groups (n = 20). Group A was the control group (no bleaching). In Group B, the specimens were bleached with Opalescence Xtra Boost (Ultradent), and in Group C, they were bleached with Smartbleach (High Tech Laser). These groups were then divided into two subgroups (n = 10 in each) according to the colorant solution used: tea and cola. Each bleaching agent was applied to the specimens according to the manufacturer′s recommendations. After bleaching, the first color of the specimens was determined with a spectrophotometer according to the CIELAB color system (∆E). Following immersion in the staining solutions, the color was determined after 15 min, 6 h (second day), and 36 h (sixth day), and the color change values were calculated. The results were analyzed statistically by two-way analysis of variance (ANOVA) and Tukey′s honest significant difference (HSD) test (P < 0.05). Results: The bleached specimens showed more staining than the unbleached specimens (control group). In all the groups, the staining was more severe in the cola solutions than in the tea solutions. There were no statistically differences in staining of the teeth in the control group (P > 0.05). In the specimens bleached with Smartbleach, staining in cola solution was greater than tea solution and this difference was statistically significant (P < 0.05). Conclusions: The staining of the bleached specimens was similar in the tea and cola solutions. The bleached specimens showed more staining than the unbleached specimens. The staining of the specimens in the tea and cola increased at all the time intervals evaluated.