Effect of whitening toothpastes on enamel color and surface roughness: A laboratory study.

Abstract

Purpose: This laboratory study evaluated the effect of toothpastes with different whitening mechanisms on the color change and surface roughness of human enamel.

Methods: 40 human maxillary incisors were sectioned at the cemento-enamel junction using a water-cooled saw. Crowns were embedded in cold acrylic with vestibular surfaces facing down. After polishing with silicon carbide papers, samples were stored in distilled water for 24 hours, then immersed in coffee solution for 6 days. Specimens were rinsed and divided into five groups (n=8): Group 1 (control), Group 2 (RSW: ROCS Sensation Whitening), Group 3 (SWN: Signal White Now Gold), Group 4 (COW: Colgate Optic White Charcoal), Group 5 (OW: Opalescence Whitening). Color was measured with a VITA Easyshade spectrophotometer, and surface roughness with a profilometer. Data were analyzed using ANOVA and Tukey HSD (P= 0.05).

Results: All groups exhibited color changes above the perceptual threshold (ΔE₀₀ > 1.8). The control group had the lowest ΔE₀₀ value, and RSW had the highest, followed by COW, with no significant difference between them (P> 0.05). Surface roughness was not significantly different between groups (P> 0.05).

Clinical significance: Bromelain-containing whitening toothpastes may provide an effective clinical option for stain removal by improving tooth color without significantly increasing enamel surface roughness.