The Effect of Mouthrinses Containing Metal Nanoparticles on Color Stability of Composite Resin

It has been demonstrated that nanoparticle-containing mouthrinses could be effective for plaque control. This study aimed to evaluate the color stability of a dental composite after exposure to several colloidal solutions containing nanoparticles. The composite specimens were prepared and immersed in distilled water for 24 hours. Then, the colors of all specimens were assessed according to the CIELAB system (First stage; baseline). Afterwards, the specimens were immersed for 24 hours in mouthrinses containing nanoTiO2, nanoZnO, nanoAg, nanoCuO, chlorhexidine (positive control) or distilled water (negative control) and color assessment was performed again (second stage; after immersion in mouthrinse). Finally, the teeth were brushed with an electrical toothbrush for 1minute, and color measurement was performed again. The level of color change between different treatments stages was compared among the study groups using ANOVA and Tukey test (α=0.05) ANOVA showed significant between-group differences in the color change among different treatment stages (P<0.05). The color change between the first and second stages was significantly lower in chlorhexidine and silver mouthwash compared to CuO and TiO2 mouthwashes. Discoloration in all groups was significantly greater than distilled water (P<0.05). The color change between the first and third stages was statistically comparable in all mouthrinse groups, and was significantly greater than distilled water (P<0.05). Nanoparticle-containing mouthwashes exhibited the same or even greater staining effect compared to chlorhexidine. Tooth brushing had little effect on stain removal from the composite specimens.