In Vitro Color Stability Assessment of Two Clear Aligner Types
DOI:
https://doi.org/10.15218/edj.2026.5Keywords:
Color, Dental Materials, Elastomers, Removable Orthodontic Appliances, Polyethylene TerephthalatesAbstract
Background and Objective: Clear aligners, widely used in orthodontic treatment, are subject to various environmental stresses that can affect their performance and esthetics. In addition, due to patient non-compliance, aligners frequently contact hot beverages such as coffee and cold beverages like cola. This study evaluates the effect of these beverages, along with artificial saliva, on the color stability of clear aligner materials.
Methods: Two types of clear aligners; Polyethylene Terephthalate Glycol (DURAN) and copolyester/ thermoplastic elastomer (CAPro), were stained using artificial saliva, cola and coffee for up to 14 days. Color stability was assessed by Vita Easyshade ADVANCE 4.0 utilizing the Commission International lightening L*a*b* color scheme.
Results: Both DURAN and CAPro aligners showed significant color changes versus baseline (p < 0.01). For DURAN, all ΔE1–ΔE1 comparisons were significant (p < 0.01) except for saliva; CAPro showed significance only in coffee (p < 0.01). Solution-based differences at both time points were highly significant for both materials (p < 0.001). Solution type had the strongest impact on color stability, followed by material and duration.
Conclusions: Color stability was significantly influenced by solution type, material, and exposure time, with the solution having the strongest effect, followed by material and time. DURAN exhibits greater resistance to staining compared to CAPro, with coffee producing the most significant discoloration, followed by cola. The degree of color change intensifies with prolonged exposure.
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