Effects of activated charcoal powder combined with toothpastes on enamel color change and surface properties

To evaluate the effects of activated charcoal powder (COAL) combined with regular (RT) or whitening (WT) toothpastes on enamel color and surface in comparison to carbamide peroxide (CP).

Dental blocks (n = 10/group) were randomly divided into COAL, COAL/RT, COAL/WT, CP, CP/RT, CP/WT, RT, WT, and CONT (without treatment). Simulated toothbrushing and whitening treatments were followed by colorimetric (ΔE₀₀ , L*, a*, b*), surface roughness (Ra), and enamel topography assays. ΔE₀₀ was submitted to two-way ANOVA and Tukey test. Color coordinates and Ra were tested with three-way repeated measures ANOVA (α = 5%).

COAL exhibited greater ΔE₀₀ than CONT (P = .048), but it did not enhance ΔE₀₀ promoted by RT or WT (P > .05). COAL alone increased Ra (P < .001) and altered enamel topography. COAL did not increase Ra caused by RT and WT (P > .05). CP exhibited the highest ΔE₀₀ (P < .05), but it raised Ra and changed enamel topography to a less extent than COAL.

Even though charcoal powder did not increase enamel Ra when combined with toothpastes, the topography was negatively impacted by COAL. Also, COAL was unable to enhance the color change of RT and WT, or reach the effectiveness of CP.

The use of activated charcoal-based product, claimed as a natural whitener, before brushing with toothpastes is not only ineffective to change the color of teeth, but also it might result in alterations on the enamel surface. Whitening with CP, instead, was effective during the same period of treatment, which still represents a more appropriate technique to whiten teeth.