Evaluation of Colour Stability of Orthodontic Ceramic Brackets and Esthetic Wires Following Immersion in Different Mouthwashes: An In Vitro Study

Abstract

Introduction: Esthetic orthodontic appliances are increasingly preferred by patients who are concerned about appearance during treatment. Ceramic brackets and coated arch wires provide a less noticeable alternative to conventional metallic appliances; however, their appearance may change following regular exposure to oral hygiene products such as mouthwashes. The colour stability of these materials is therefore important for maintaining esthetics throughout orthodontic treatment. Aim and Objectives: The study aimed to evaluate the colour stability of monocrystalline and polycrystalline ceramic brackets and Teflon-, ceramic-, and epoxy-coated esthetic arch wires after exposure to Listerine, fluoride-containing, and probiotic mouthwashes. Materials and Methodology: A total of 100 specimens were evaluated, including 40 ceramic brackets (20 monocrystalline and 20 polycrystalline) and 60 esthetic arch-wire segments (20 each of Teflon-, ceramic-, and epoxy-coated wires). Each material was divided into four subgroups and exposed to Listerine, fluoride-containing mouthwash, probiotic mouthwash, or distilled water as the control. Colour changes (ΔE) were recorded at different time intervals, and the data were analysed using repeated-measures ANOVA. Results: A gradual increase in colour change was observed in all materials over time, with statistically significant differences (p = 0.001). Polycrystalline brackets generally showed slightly more discolouration than monocrystalline brackets. Among the arch wires, epoxy-coated wires showed greater colour change in Listerine and fluoride mouthwashes, while ceramic-coated wires showed slightly higher values in probiotic mouthwash. Only minor changes were observed in the control groups. Discussion: Although colour changes increased with exposure time, the values remained well below the clinically perceptible level. The response varied slightly depending on the type of bracket, wire coating, and mouthwash used. Probiotic mouthwash produced comparatively less colour change in ceramic brackets. Overall, the observed changes were small and unlikely to affect the clinical appearance of the tested materials. Conclusion: Within the limitations of this in-vitro study, ceramic brackets and esthetic-coated arch wires showed good colour stability in all three mouthwashes. Although small changes in colour occurred over time, these changes were unlikely to be clinically noticeable. The findings suggest that the tested mouthwashes have minimal effect on the colour stability of these esthetic orthodontic materials.

Keywords: Colour stability, ceramic brackets, esthetic arch wires, Listerine, fluoride mouthwash, probiotic mouthwash, orthodontics.