Influence of whitening and regular dentifrices on orthodontic clear ligature color stability.

OBJECTIVES: This study evaluated the effect of brushing orthodontic clear ligatures with a whitening dentifrice containing a blue pigment (Close Up White Now, Unilever, London, UK) on their color stability, when exposed to a staining agent. MATERIALS AND METHODS: Ligatures from 3M Unitek (Monrovia, CA, USA) and Morelli (Sorocaba, SP, Brazil) were tested. Baseline color measurements were performed and nonstained groups (control) were stored in distilled water whereas test groups were exposed for 1 hour daily to red wine. Specimens were brushed daily using regular or whitening dentifrice. Color measurements were repeated after 7, 14, 21, and 28 days using a spectrophotometer based on the CIE L*a*b* system. RESULTS: Decreased luminosity (CIE L*), increased red discoloration (CIE a* axis), and increased yellow discoloration (CIE b* axis) were generally observed for ligatures exposed to the staining agent. Color variation was generally lower in specimens brushed with regular dentifrice, but ligatures brushed with whitening dentifrice were generally less red and less yellow than regular dentifrice. The whitening dentifrice led to blue discoloration trend, with visually detectable differences particularly apparent according to storage condition and ligature brand. CONCLUSIONS: The whitening dentifrice containing blue pigment did not improve the ligature color stability, but it decreased yellow discoloration and increased a blue coloration. CLINICAL SIGNIFICANCE: The use of a whitening dentifrice containing blue pigment during orthodontic treatment might decrease the yellow discoloration of elastic ligatures.

Color stability of five orthodontic clear elastic ligatures.

AIM: In this study the color stability of five commercially available orthodontic clear elastic ligatures daily exposed to a staining agent (red wine) was investigated. METHODS: The commercial brands tested were 3M Unitek, Abzil, American Orthodontics, Dentsply GAC, and Morelli. Baseline color readings (Commission Internationale de l'Eclairage [CIE] L*a*b* parameters) of 20 ligatures for each brand were carried out using a spectrophotometer. The ligatures were divided in two groups (n = 10): one group remained immersed in distilled water (control) throughout the period, while the other group was daily exposed to red wine (1 hour of immersion). Immersion media were daily renewed. Successive color readings were carried out after 7, 14, 21, and 28 days, and the chromatic variations calculated. Color variation data were analyzed by two-way repeated measures analysis of variance and Student-Newman-Keuls test (P < .05). RESULTS: Storage in water increased staining until 14 days, and color receded after this period, irrespective of the brand. After 28 days of immersion in water, no significant difference among the commercial brands was observed. For the groups exposed to red wine, a significant increase in staining over the course of time was detected, irrespective of the brand. Ligatures from GAC and Morelli showed higher staining than the other materials, irrespective of the evaluation time. Ligatures from 3M Unitek and American generally showed lower pigmentation than the other brands. CONCLUSION: Exposure to a staining agent, cumulative exposure time, and commercial brand are factors that influence the color stability of clear elastic ligatures.