Related Experiment Video
Updated: Sep 20, 2025
Author Spotlight: 3D Movement Assessment of Maxillary Posterior Teeth in Clear Aligner Treatment
Published on: February 23, 2024
Cytotoxicity assessment of different clear aligner systems: An in vitro study
Objectives:
To evaluate and compare the cytotoxicity of multiple clear aligner systems (Invisalign, Eon, SureSmile, and Clarity).
Materials And Methods:
A cytotoxicity assessment was carried out by immersing three sets of aligners from the included four systems in normal saline for 1 month at 37°C. The solutions were then diluted to three different concentrations (5%, 10%, and 20% volume/volume). Gingival fibroblasts were exposed to the solution after being seeded to 96-well microplates for 48 hours, and the medium was substituted with an MTT solution (MTT: 3-[4,5-dime- thylthiazol-2-yl]-2,5-diphenyltetrazolium bromide). Optical density was then measured to determine cell viability and evaluate cytotoxicity subsequently.
Results:
Cytotoxicity comparison showed no statistically significant difference among the four included systems. However, when cell viability of each system was compared with the control, a significant difference was reported at the 10% and 20% solution concentrations. The Clarity system had the lowest toxicity across all solution concentrations.
Conclusions:
The thermoplastic materials used by all tested systems (Invisalign, Eon, SureSmile, and Clarity) presented some degree of toxicity (slight to moderate), with statistically significant mean differences compared with the control.
