Activated Charcoal vs. Chemical Whitening Agents: Effects on Human Enamel

Objectives: The promotion of activated charcoal to whiten teeth has appeared in social media but little scientific evidence of its efficacy or deleterious effects exists in the literature. The aim of this study was to compare the effect of activated charcoal versus chemical whitening agents on human enamel’s color and surface roughness.
Methods: Extracted adult human molars were collected, disinfected with 1% thymol solution for 48 hours, sectioned and mounted exposing enamel, and ground/polished with SiC/alumina. Prepared samples were stained with coffee via submersion for 96 hours. The samples were then randomly divided into 3 groups (n=5/group). All groups were stored in distilled water except when being treated. The control group samples were wet brushed with a soft toothbrush for 2 minutes every day for 6 days. The two experimental groups were treated with activated charcoal (Carbon Coco) or a conventional chemical whitening agent (Opalescence, carbamide peroxide) according to manufacturer’s instructions for 6 days. They were also brushed in the same manner as the control group. All samples were tested for color and surface roughness via a spectrophotometer and a 3D measuring laser microscope, respectively. Color and surface roughness changes were compared with ANOVA/Tukey and t-tests.
Results: Color changes (ΔE) from day 0 to day 6 were 4.1±1.3, 11.9±4.0, and 6.6±1.7 for the control, chemical whitening, and activated charcoal groups, respectively. The color change in the chemical whitening group was significantly (p<0.05) greater than the control and activated charcoal treated teeth. Brushing and treatment with the whitening agents did not significantly (p>0.05) alter the surface roughness of the teeth between day 0 and day 6.
Conclusions: Conventional chemical whitening of teeth was more effective in producing color change than activated charcoal and brushing alone. Neither method significantly increased the surface roughness of enamel.