Effects of different whitening toothpastes on resin composite: A laboratory study

To evaluate the laboratory effects of different whitening toothpastes on resin composite with respect to color change and surface roughness.

A total of 50 disc-shaped specimens were prepared from a microhybrid composite (Zenchrom). The samples were randomly divided into five groups for the application of four different whitening toothpastes (Opalescence Whitening Toothpaste, Rocs Sensation Whitening, Luis Bien Active Carbon Toothpaste and Sparkly White Herbal Toothpaste) and one non-whitening toothpaste (Signal Anti-Caries Toothpaste) (n=10). For staining, the samples were kept in coffee solution. Then, all samples were brushed 5,000 strokes with a toothbrush device to simulate a 6-month brushing period. Color measurements of the specimens after staining and brushing were performed using a spectrophotometer. Surface roughness measurements were performed using a mechanical profilometer. The Shapiro-Wilk test, one-way ANOVA and Kruskal-Wallis H test were used for the statistical analysis of the data (P<  0.05).

Following the brushing procedures, a significant increase in surface roughness was observed in all the samples (P<  0.05). When the roughness values were compared between the groups after 6 months of brushing, a statistically significant increase in surface roughness was observed with Signal Anti-Caries Toothpaste compared to Luis Bien and Opalescence (P< 0.05). In the evaluations of the color changes, all the toothpastes had whitening effects, but no statistically significant difference was detected between the toothpastes with respect to whitening performance (P> 0.05).

Whitening toothpastes may lighten the color of the resin composite tested, but they can also increase surface roughness. Therefore, dentists should guide patients in selecting appropriate toothpaste products.