Effectiveness of Activated Charcoal Toothpaste vs. 6% Hydrogen Peroxide Whitening Pen—An In Vitro Study

<b>Background:</b> Tooth whitening is a widely sought-after cosmetic procedure, with various at-home and professional treatments available. This study compares the whitening efficacy of an activated charcoal toothpaste and a 6% hydrogen peroxide whitening pen under controlled in vitro conditions. <b>Methods:</b> Twenty freshly extracted human teeth were stained with a coffee solution and divided into two groups. Group A underwent daily applications of activated charcoal toothpaste for 30 days, while Group B received a single 5 min application of a 6% hydrogen peroxide whitening pen. Tooth color was assessed using the VITA Classical A1-D4 Shade Guide at baseline, mid-treatment, and post-treatment for Group A and at baseline and immediately after treatment for Group B. <b>Results:</b> The activated charcoal toothpaste exhibited a gradual whitening effect, with the most significant improvements occurring within the first two weeks (<i>p</i> < 0.01), after which the whitening effect plateaued. In contrast, the hydrogen peroxide whitening pen produced immediate and substantial whitening (<i>p</i> < 0.001). Statistical analysis using the Wilcoxon signed-rank test and Mann-Whitney U test confirmed the superior efficacy of the hydrogen peroxide treatment. <b>Conclusions:</b> The hydrogen peroxide whitening pen was significantly more effective in achieving rapid and substantial whitening compared to the activated charcoal toothpaste, which provided gradual but limited improvements. Further clinical studies are needed to evaluate the long-term color stability.