Color Stability of Orthodontic Elastomeric Ligatures in the Oral Environment: A Clinical Trial

Objectives: Despite the recent advances in orthodontic appliances, color change of elastomeric ligatures over time remains a problem causing patient dissatisfaction. This study aimed to assess the color stability of different types of orthodontic elastomeric ligatures in the oral environment. Materials and Methods: This clinical trial was conducted on 67 patients. After applying the exclusion criteria, 11 participants were excluded, and 56 remained. Four different brands of elastomeric ligatures namely Ortho Technology, Ortho Organizers, American Orthodontics, and SIA were randomly used in the four quadrants of each patient (n=14 from each brand). Discoloration of ligatures was scored in the oral cavity by orthodontists and patients on the day of placement (T0) and 28 days later (T1). Photography and CIE L*a*b* color space were used to assess the color change (∆E). Data were analyzed by the Kruskal-Wallis and Bonferroni tests. Results: All brands showed discoloration. The highest ∆E was identified in SIA and Ortho Technology, while the lowest was recorded in Ortho Organizers. The lowest ∆b (yellowness) and the greatest reduction in L* (lightness) and ∆a (redness) were observed in Ortho Organizers. According to the opinion of patients and orthodontists at T0 and T1, SIA was the least visible followed by Ortho Technology. No significant difference was found between orthodontists and patients at T0 and T1 regarding the visibility of ligatures (P>0.05). Conclusion: After 28 days, all brands of elastomeric ligatures showed considerable discoloration. Ortho Organizers showed the highest color stability.