Tooth Stain Removal with Cocoa Powder : Its Effectiveness and Possibility of Application as a Dentifrice

In this in vitro and clinical study, cocoa powder, which is used as a drink and a food ingredient, was tested to evaluate its usefulness as a dentifrice. In the in vitro study, cocoa solution (0.2g/ml) was prepared by mixing pure cocoa powder and distilled water. The control group consisted of CaHPO₄ solution (0.2g/ml) and distilled water. The surface of extracted bovine teeth was stained after immersing in a tea solution. These stained teeth were divided into three equal groups and polishing was carried out for each group using cocoa solution, CaHPO₄ solution and distilled water. Polishing was per-formed on the labial surface of the teeth using a polishing brush while conforming to the same experimental conditions for all three groups. The color of the labial surface of each group was measured with a spectrocolorimeter using the CIEL*a*b*, before being subjected to staining, after staining, 3min after polishing and 6min after polishing. The color difference (ΔE*ab) between after staining and 3min after polishing, and between after staining and 6min after polishing were measured, and the significance of difference for each polishing agent was calculated using Tukey's multiple comparison (α=0.05). To investigate whether cocoa solution itself causes staining, bovine teeth were immersed in a separately prepared cocoa solution (4g/100ml). The color change after this procedure was compared with that caused by immersing the teeth in a tea solution. In the clinical investigation, anterior teeth were divided into two groups and polished with either of two solutions: polishing solution containing cocoa or a placebo solution which did not include cocoa. The patients were instructed to brush their anterior teeth using one of these two solutions for 1 month, after which the color difference was measured. The results were analyzed with the Mann-Whitney U test (α=0.05). In the case of the in vitro experiment, there was a statistically significant difference between the color difference after polishing with cocoa solution and that of the distilled water. Moreover, as for the color difference, there was no significant difference between cocoa solution and CaHPO₄ solution. There was no difference between 3 and 6min after application for each polishing agent. Unlike tea solution, no color change was observed when the teeth were immersed and kept in cocoa solution. As for the clinical test, there was no significant difference between cocoa solution and placebo solution. From the above results, the solution containing cocoa was shown to remove stains from the surface of teeth in vitro, however, such capability was not confirmed under the limited conditions employed in the clinical investigation.