Effect of Two Whitening Toothpastes on Composite Resin Restorations Discolored by 0.2% Chlorhexidine Mouthwash

This study compared the effect of two whitening toothpastes on composite specimens discolored with 0.2% chlorhexidine (CHX).

Twenty-four composite specimens were fabricated from Charisma Diamond composite resin. The initial color of specimens was measured according to theCIE L*a*b* color system using a spectrophotometer. The specimens were immersed in 0.2% CHX twice a day for 1 minute each time, for 2 weeks. The color of specimens was measured again, and the specimens were assigned to three groups (n=8). The control group specimens were immersed in distilled water. The two test group specimens were brushed twice daily for 21 days with Oral B toothbrush and Signal White Now and Crest 3D White whitening toothpastes each time for 30 seconds. The color of specimens was measured again. Data were analyzed by one-way ANOVA and t-test.

CHX increased the a, b, and L color parameters in all groups. There were no significant differences in ΔL (P=0.10), Δa (P=0.24), and Δb (P=0.07) among the study groups. The a, b, and L parameters decreased after brushing the specimens discolored with 0.2% CHX with the whitening toothpastes. There were significant differences in ΔL (P=0.03), Δa (P=0.02), and Δb (P=0.01) among the three study groups after using the whitening toothpastes. The highest ΔL, Δa, Δb, and ΔE values were recorded in Crest 3D White group, followed by Signal White Now group.

Crest 3D White whitening toothpaste had higher efficacy to resume the original color of composite specimens discolored with 0.2% CHX.