The Effects of Staining and Cleaning on the Color and Light Transmittance Changes of a Copolyester Retainer Material with Different Surface Textures

Abstract

This study evaluated the efficacy of different cleaning methods with respect to changes in the color and light transmittance of both rough and smooth thermoformed, copolyester retainer specimens, after staining in different solutions. Four hundred copolyester sheets (Essix ACE) specimens were fabricated over molds with different surface textures, smooth and rough. The specimens were stained in four different solutions (n = 100 per solution) over 28 days; then, each of the four groups of 100 stained specimens was sub-divided into five groups of 20 specimens and subjected to a different destaining solution. The specimens were sub-divided with half subjected to an additional ultrasonic cleaning procedure. Light transmittance and color changes were analyzed using a spectrometer/integrating sphere assembly and a spectrophotometer. Mean difference comparisons were performed using appropriate statistical tests at p = 0.05. All five destaining solutions proved to be effective at removing coffee and tea stains. The surface roughness of the retainer material plays a significant role in the ability of cleaning solutions to remove stains, demonstrating a greater effect on cleaning rough specimens with respect to improvements in light transmittance and greater changes in color. Additionally, an ultrasonic cleaning unit generally enhanced the ability of all five solutions to clean the tea-stained specimens. However, the enhancements were only significant for light transmittance.

Coffee Staining and Simulated Brushing Induced Color Changes and Surface Roughness of 3D-Printed Orthodontic Retainer Material

“…Due to the aesthetic aspects and reasonable treatment times, clear retainers have become popular as orthodontic procedures have advanced. These clear retainers must be maintained to prevent loss of material integrity because interactions between clear retainer material and the oral environment can result in plaque and calculus formation and bacteria buildup and retention on the retainer surface [50]. In the current study, copolyester thermoplastic sheets were used to fabricate the conventional VFRs and compare them with 3D-printed retainers.…”

“…Color stability is an important property for a dental appliance, especially for clear or esthetic appliances. The color is affected by intra-oral aging, ultraviolet radiation, mouthwash, and various dietary beverages [50]. In this study, the retainers were immersed in coffee beverages, partly due to its chromogenic nature of inducing discoloration and because it is a commonly consumed beverage worldwide [17].…”

Comparison of light transmittance and color changes between polyurethane and copolyester retainer materials after staining and destaining

“…To maintain good compliance with clear retainer wear, transparency and color stability of clear retainers need to be maintained, and they are critical considerations for patients and clinicians [ 5 ]. Few studies investigated the long-term effectiveness of cleaning solutions for maintaining color stability and light transmittance of clear thermoplastic retainers [ 6 – 9 ]. However, characterizing the ability to remove a “stain” once it has occurred requires further investigation [ 10 ].…”

“…Studies showed that different cleaning solutions affected the mechanical and physical properties of different thermoplastic retainer materials, including light transmittance, surface roughness, and flexural modulus [ 6 – 8 ]. A report showed that the surface roughness of copolyester material plays an important role in its ability to be stained or destained [ 9 ]; however, the comparison of stained-retainer thermoplastic materials with different surface roughness has never been studied in the aspect of staining and destaining. Therefore, this study aimed to compare the changes in light transmittance and color between two retainer materials, polyurethane and copolyester polymers, with different surface textures, rough and smooth surfaces after they have been stained and destained in various solutions.…”

Comparison of Light Transmittance and Color Changes between Polyurethane and Copolyester Retainer Materials after Staining and Destaining.

“…To maintain good compliance with clear retainer wear, transparency and color stability of clear retainers need to be maintained, and they are critical considerations for patients and clinicians [5]. Few studies investigated the long-term effectiveness of cleaning solutions for maintaining color stability and light transmittance of clear thermoplastic retainers [6][7][8][9].…”