Colour stability of stained composite resins after brushing with whitening toothpaste.

OBJECTIVE

The aim of this study was to evaluate the effect of brushing with whitening toothpaste on the colour change of composite resins discoloured with coffee.

METHODS

Disc-shaped samples were prepared using one nano-hybrid (Clearfil Majesty Esthetic), one micro-hybrid (GC G-aenial Anterior) and one nano-ceramic composite (Zenit) (n = 6). After initial colour measurements, the samples were coloured in the coffee solution for 5 days. Colour measurements were made again after the colouring process, and brushing simulation was applied for 7, 15 and 30 days with two different whitening toothpastes containing calcium carbonate+perlite (Signal whitening system, SWN) and hydrated silica+hydrogen peroxide (Colgate optic White, COW) and a conventional non-whitening toothpaste containing hydrated silica (Sensodyne pronamel, SPN). Colour change (∆E ) after brushing was calculated using the CIEDE2000 system. Repeated measures variance analysis was used for the analysis of data.

RESULTS

G-aenial anterior and Zenit showed significant coloration compared to Majesty esthetic after coloration with coffee (p < 0.05). The colour change in all composite resins was above the clinically acceptable limit (ΔE  > 1.8). Colour change over time after brushing with both whitening toothpastes differed significantly (p < 0.05). SWN and COW exhibited a significantly higher whitening effect than SPN (p < 0.05). While there was no significant difference in composite groups brushed with the SWS (p > 0.05), there was a significant difference between Majesty esthetic, G-aenial anterior and Zenit in groups brushed with COW (p < 0.05).

CONCLUSIONS

Colour change was high in micro-hybrid and nano-ceramic composites which were discoloured in coffee. The whitening toothpastes were effective in reducing the coloration caused by coffee.