Effect of whitening dentifrices on dental enamel: an analysis of color, microhardness, and surface roughness in vitro

Objectives: This study aimed to evaluate the influence of differ ent whitening toothpastes on color change and alteration in enamel surface roughness and microhardness compared to a conventional toothpaste. Method and materials: Fifty bovine incisors were selected, cleaned, and stored before being divided Into five groups: a conventional toothpaste group and three whitening toothpaste groups containing different abrasive agents: silica, hydrogen peroxide, and activated charcoal. Spec- imens underwent simulated brushing, staining with black tea solution, and subsequent analyses of color, surface roughness, and microhardness. Statistical analysis was performed using three-way ANOVA and Tukey post-hoc tests (P<.05). Results: The results showed that the color analysis revealed similar 1 whitening potential among all toothpastes. They showed signif- icant differences in surface roughness (P<.001) and microhard- ness (P<.001) after simulated brushing. While all toothpastes caused a decrease in microhardness, the charcoal-based tooth- paste showed a significant increase in surface roughness com- pared to the initial condition. Conclusion: All toothpastes demonstrated whitening capability. Surface roughness changed after brushing with activated charcoal-based whitening tooth- paste, but final roughness was similar across all groups. Whiten- ing toothpastes led to a decrease in enamel microhardness, with similar final performance across all toothpastes analyzed.