Evaluation of Coffee Stain Removing Efficacy of Commercially Available Dentifrices Containing Natural Ingredients: An In Vitro Study

Aims and background:This study aims to assess the effectiveness of natural ingredients like papain, bromelain, and charcoal-containing whitening dentifrices in eliminating coffee stains from tooth surfaces in vitro. Materials and methods: A total of 76 extracted human central incisors were randomly allocated to each of the four groups: group A (n = 19)— papain and bromelain dentifrice, group B (n = 19)—charcoal-based dentifrice, group C (n = 19)—chemical-based dentifrice, and group D (n = 19)—only powered toothbrush. After being submerged in coffee extract for 4 weeks, the stained tooth surface of the specimens was brushed for 10 seconds daily for 4, 8, and 12 weeks using a powered toothbrush and the designated dentifrice. Simultaneously, the L*, a*, and b* values were assessed by spectrophotometric analysis using the CIELAB system before and after staining, and after brushing at each time point, to determine the ΔL, Δa, Δb, and ΔE. Data were recorded and statistically analyzed. Results: After 4 weeks of brushing, tooth whiteness (ΔL) increased significantly in all four groups (group B = 4.07 ± 3.32 > group A = 2.30 ± 1.14 > group C = 1.92 ± 1.24 > group D = 1.37 ± 1.83) (p < 0.05). However, beyond 4 weeks, decreased whitening effect was observed in all the brushing regimens (group B = 1.49 ± 0.74 > group A = 1.31 ± 0.67 > group C = 1.03 ± 0.79 > group D = 0.85 ± 0.64), which was significant in group B (p < 0.001) but insignificant in all other groups (p > 0.05). At 12 weeks, the greatest color change (ΔE) was observed in group B (1.51 ± 0.84), followed by group A = 1.25 ± 0.67 > group C = 1.15 ± 0.66 > group D = 0.95 ± 0.55 (p < 0.001). Conclusion: Both papain–bromelain and charcoal-based whitening dentifrices significantly improved tooth whiteness over 4 weeks compared to chemical-based whitening dentifrices. After 4 weeks, the whitening effect of all three dentifrices diminished, although the charcoal dentifrice was better than the other two. Clinical significance: Although charcoal-based dentifrice produced better results, papain–bromelain-based dentifrices administered for 4 weeks might be safer for coffee stain removal and tooth whitening, as charcoal is abrasive and damages tooth enamel.