Color Stability of PET-G in Clear Aligners: Impact of Prolonged Exposure to Everyday Substances and Its Psychological and Social Implications †

Abstract

The aesthetics of clear aligners is a critical factor that can influence patient satisfaction and psychological and social well-being. However, their transparency can be compromised by exposure to staining agents. This study aimed to evaluate the color stability of PET-G aligners following prolonged exposure to common daily substances, including food, tobacco products, and cleaning agents. Flat samples of PET-G (n = 220) were immersed in various solutions, including coffee, tea, Coca-Cola, red wine, a colloidal silver-based disinfectant, nicotine, artificial saliva, cigarette smoke, and mixtures of saliva with smooth, coffee, and nicotine. Immersion times of 10 (n = 110) and 15 days (n = 110) were randomly assigned. Colorimetric assessments were conducted by measuring L*a*b* parameters before and after immersion, and total color change (ΔE) was calculated. Non-parametric statistical tests revealed significant color changes in PET-G samples after both immersion durations, with pairwise comparisons indicating notable differences in ΔE values among groups exposed to different substances, particularly coffee, tea, and Coca-Cola. The findings highlight the psychological and social impact of aligner staining on patient confidence and compliance. Understanding these effects highlights the need for enhanced patient education to improve aligner aesthetics and satisfaction.