Color stability of bleached tooth enamel brushed with different stain-removing toothpastes

ObjectiveThe effects of four toothpastes on the color stability of in-office bleached tooth specimens were determined.Materials and MethodsWe evaluated an experimental toothpaste (EXP) and three commercially available toothpastes: Colgate Optic White (OPW), Aquafresh White & Protect (AWP), and Crest 3D White (CDW). OPW, AWP, and CDW contained inorganic abrasives, whereas EXP and AWP contained sodium polyphosphate. Forty-eight randomly selected human-extracted maxillary central incisors were bleached and brushed twice daily over 30 days. We analyzed the final color difference (Delta E*ab, Delta E00, Delta WID), arithmetic average surface roughness (Ra) of the enamel measured on days 0 and 30, and scanning electron microscopy images of enamel surfaces and toothpastes. Delta E*ab, Delta E00, Delta WID, and Ra were analyzed using one-way analysis of variance and Tukey's test (alpha = 0.05).Results Delta E*ab and Delta E00 values were significantly lower after toothbrushing with EXP, OPW, and CDW than with AWP. OPW induced the greatest positive Delta WID. Ra was significantly increased by OPW and CDW, but slightly increased by AWP, with cube-like particles, and EXP, with no particle-like structures.ConclusionsOnly EXP stabilized the color of bleached teeth without increasing the enamel surface roughness. Sodium polyphosphate with approximately 10 phosphate groups was effective at removing stains.Clinical SignificanceThe effect of toothpaste on the color stability of bleached teeth depends on the constituting abrasives and chemical components. Polyphosphoric acid has different stain-removal effects depending on its degree of polymerization. Additionally, although certain types of abrasives may be effective for color stability, they also increase the surface roughness of the enamel.