A Comparative Analysis of Staining Effects on Translucency in Two Transparent Retainers Exposed to Various Cleansers

Objectives: Due to their aesthetic appeal and translucent properties, clear thermoplastic retainers have become increasingly popular. However, ensuring their proper maintenance and cleaning is a significant challenge. It is essential to prevent any negative impact of cleaning solutions on the translucency and color consistency of retainers. Therefore, this study aimed to assess the effect of different cleaning solutions on the light transmission (translucency) rate of two distinct types of clear thermoplastic sheets. Materials and Methods: Two different clear thermoplastic sheets (Erkodent, Shodental), and five disinfectant solutions including chlorhexidine, Listerine, hydrogen peroxide, GUM whitening, and acid acetic served as the study materials and distilled water was used as control. The samples in each group (N=12) were immersed in the respective solutions for 15 minutes, twice a week and their light transmittance was measured using spectrophotometry after one and three months. Statistical analysis was conducted using two-way analysis of variance, with the significance level set at P<0.05 Results: Light transmittance decreased from baseline to 3 months for all study groups. After three months, the lowest translucency was related to retainers manufactured with Erkodent sheets, cleaned with GUM whitening (74.11±10.72%). The highest translucency after this period was found in retainers prepared with Shodental sheets immersed in Listerine mouthwash (88±1.55%). Only retainers treated with hydrogen peroxide showed significant difference between the thermoplastic sheets, which was higher in Erkodent (P<0.05). Conclusion: Our findings indicated that among the studied solutions, cleaning translucent retainers with Listerine mouthwash twice a week has the least effect on light transmission.