The Effectiveness of Different Cleaning Methods for Clear Orthodontic Aligners: Impacts on Physical, Mechanical, and Chemical Properties-An In Vivo Study

Abstract

Maintaining the cleanliness of orthodontic aligners is crucial for oral hygiene and preserving the optical properties of aligners. In this randomized clinical trial, we compared the effectiveness of different cleaning methods for the maintenance of Invisalign clear aligners. Twelve adult patients received five aligners, each worn for 10 days. The aligners were divided based on the cleaning method: tooth brushing with whitening toothpaste, vinegar, Fittydent Super Cleansing Tablets, Invisalign cleaning crystals, and only water. Scanning electron microscopy (SEM) was used to detect surface morphology changes; color changes (ΔE) were evaluated using a spectrophotometer. Fourier transform infrared spectroscopy (FTIR) with a diamond hemisphere was used to study the aligners' chemical compositions. Nanoindentation testing was used to assess changes in the elastic modulus. SEM confirmed the effectiveness of Invisalign cleaning crystals in maintaining cleanliness, revealing a surface similar to that of the control group with no adverse effects. Color stability analysis revealed significant ΔE value differences; whitening toothpaste had significantly lower ΔE values than water and Invisalign cleaning crystals. The elastic modulus and FTIR analyses indicated no significant differences between the cleaning methods. Therefore, Invisalign cleaning crystals and whitening toothpaste are safe for aligner maintenance, showing successful and aesthetically pleasing results.

Keywords: aligners; cleaning method; color stability; orthodontics; thermoplastic material.

Figure 1

(A) Samples were gold-coated with a quorum sputter coater for scanning electron microscopy imaging. (B) Samples were loaded for surface morphology examination using a Zeiss device (EVO-LS10, Cambridge, UK).

Figure 2

Scanning electron microscopy images of the control group.

Figure 3

Scanning electron microscopy images of Group A.

Figure 4

Scanning electron microscopy images of Group B.

Figure 5

Scanning electron microscopy images of Group C.

Figure 6

Scanning electron microscopy images of Group D.

Figure 7

Scanning electron microscopy images of Group E.

Figure 8

Fourier transform infrared spectroscopy-attenuated total reflectance data of the five study groups showing all the peaks that are similar to the standard peak.