Cytotoxicity of three commercial orthodontic elastomeric ligature brands

¹ Research Office, Faculty of Dentistry, Mahidol University, 6 Yothee Road, Rajthevee, Bangkok Thailand
² Postgraduate student of specialty training program in Orthodontics, Faculty of Dentistry, Mahidol University, 6 Yothee Road, Rajthevee, Bangkok Thailand
³ Department of Orthodontics, Faculty of Dentistry, 6 Yothee Road, Rajthevee, Bangkok Thailand
⁵ National Metal and Materials Technology Center, National Science and Technology Development Agency, Ministry of Science and Technology

Abstract

This study aimed to evaluate cytotoxicity of three commercial brands of orthodontic elastomeric ligatures. Materials and Methods: The three commercial orthodontic elastomeric ligature brands were C-brand, T-brand and U-brand from different manufacturing countries. The cytotoxic assay was performed using cell cultures (L929) which were subjected to the cell viability test with methyl-tetrazolium (MTT). The L929 cell line was grown in 96-well tissue culture plates (1×10⁵ cells/cm³). Elastomeric ligatures (0.2 g) from each brand was placed in 1 ml of Minimum Essential Medium (MEM) at 37°C with 5% CO₂ at 100% humidity in an incubator for 24 hours. After incubation, the cell mitochondrial activity was evaluated by the MTT test for detecting viable cells from optical density according to ISO 10993-5: 2009 (E) test procedure. Cytotoxic effects were determined by the percentage of cell viability. Results: Microscopic investigation showed that all commercial elastomeric ligatures caused alterations in the fibroblast cell morphology from an elongated to a spherical form. The cell viability of C-brand, T-brand and U-brand were 51.10, 73.04 and 93.04%, respectively. Conclusion: T-brand and U-brand orthodontic elastomeric ligatures were non cytotoxic potential. U-brand had the greatest cell viability and C-brand had the lowest cell viability at 24 hours.