Evaluation of the efficacy of a charcoal-based tooth whitening dentifrice on coffee stains: an in vitro study.
Level 5 - mechanism / opinion, no new human data
In vitro laboratory study on extracted teeth
What was done
Thirty-three extracted human tooth specimens were stained in coffee extract for 4 weeks and randomly assigned to 3 groups (n = 11 per group): charcoal-based whitening dentifrice (CBWD), non-charcoal-based whitening dentifrice (NCBWD), or distilled water (DW). Specimens were brushed with an electric toothbrush for 8 seconds daily for 4 weeks. Spectrophotometric measurements using the CIELAB system (L*, a*, b*) were taken before staining, after staining, and after brushing to calculate color change (ΔE) and whiteness change (ΔL).
What was found
Brushing significantly improved tooth whiteness values (ΔL) across all 3 groups (p = 0.003), with the greatest improvement reported in the CBWD group. However, overall color change (ΔE) was not significantly different between the CBWD, NCBWD, and DW groups. The abstract reports no specific numerical values for ΔE or ΔL.
Why it matters
These findings suggest that adding charcoal to whitening dentifrice offers no measurable advantage over standard whitening dentifrice or brushing with water alone for coffee stain removal.
Limits
This was an in vitro study on extracted teeth, which does not simulate intraoral dynamics such as saliva, pellicle formation, or dietary wear. The sample size was small (33 total specimens). Adverse effects such as enamel surface roughness or abrasiveness were not reported in the abstract, and exact numerical effect sizes were omitted.
Cited by
- supports Charcoal in toothpaste has no intrinsic whitening effect and functions only through adsorption of tannins from the tooth pellicle.