L929 cell cytotoxicity associated with experimental and commercial dental flosses

Abstract

© 2017 Published under licence by IOP Publishing Ltd. This aim of the study was to investigate the cytotoxicity of two commercial and two experimental dental flosses. Two commercial, Oral B® Essential Floss (nylon-waxed) and Thai Silk Floss (silk-waxed), and two experimental, Floss X (nylon-waxed) and Floss Xu (nylon-unwaxed) dental flosses were used. The cytotoxic assay was performed by using cell cultures (L929) which were subjected to cell viability test with methyl-tetrazolium. Each floss specimen (0.4 g) was placed in 1 ml of Minimum Essential Medium at 37°C with 5% CO2at 100% humidity in an incubator for 24 hours. After incubation, the cell mitochondrial activity was evaluated for detecting viable cells using optical density as per the guidelines of ISO 10993-5:2009(E). Cytotoxic effects were evaluated by measuring percentage of cell viability at 3 points of time- 5 mins, 30 mins, and 1 hr. The results showed that two commercial dental flosses and Floss X had cell viability about 90% at the three time points; however, the experimental Floss Xu presented 80% cell viability at 5 min and <70% cell viability at 30 min and 1 hr. The results concluded that the commercial dental flosses and the experimental dental floss with wax tested in this study were acceptable for clinical use.