Evaluation of the Effect of Two Bleaching Techniques on Color Improvement Resin Composite Restorations Discolored by %0.2 Chlorhexidine

Discoloration of resin composite restorations cause patient dissatisfaction. Chlorhexidine mouthwash is an agent that causes significant discoloration of resin composite. The aim of this study was to investigate and compare the effectiveness of two methods of home bleaching and strip bleaching on resin composite samples that are discolored by 0.2% chlorhexidine.

In this in-vitro experimental study number of 24 disc-shaped samples were fabricated from Charisma Diamond resin composite. The initial color of samples was measured by CIE Lab system in spectrophotometer. The samples were immersed in the 0.2% chlorhexidine mouthwash for 2 weeks twice a day for 1 minute each time. The color of the samples was measured again. Samples were divided into 3groups (n = 8). One group was placed in distilled water as the control group. The next two groups were exposed to the effects of home bleaching with 20% carbamide peroxide gel and Crest 3D white luxe white strip. The color of the samples was measured for the last time. Data were analyzed with One-way ANOVA (α = 0.05).

The amount of l, a and b increased by 0.2% chlorhexidine mouthwash in all groups. However, no statistically significant difference was observed between the groups (p value > 0.05). After using bleaching techniques on samples were discolored by 0.2% chlorhexidine mouthwash, l, a and b decreased and the difference between the groups was statistically significant (p value < 0.05).

All of the samples were discolored by 0.2% chlorhexidine mouthwash. After using the bleaching techniques, the rate of color return in home bleaching and strip bleaching was higher than the control group.