Color stability of five orthodontic clear elastic ligatures

In this study the color stability of five commercially available orthodontic clear elastic ligatures daily exposed to a staining agent (red wine) was investigated.

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).

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.

Exposure to a staining agent, cumulative exposure time, and commercial brand are factors that influence the color stability of clear elastic ligatures.