In Vitro evaluation of immediate cytotoxicity of resterilised orthodontic bands on HGF-1 cell line

Objectives > The aim of this study was to evaluate the immediate cytotoxic effects of orthodontic molar bands, on HGF-1 cell line, after multiple times of sterilization following size selection procedure. Material and methods > 48 stainless steel orthodontic molar bands were divided into 4 groups according to times of sterilization (1, 2, 4 and 8 times). A liquid extract containing the ions released from each band was prepared and the HGF-1 cell line was exposed to the extracts. 2 control groups (positive and negative) were designated. An MTT assay was performed, and the absorbance was read at 492 nm in a microplate reader (Antos 2020, Austria). Results > There was no significant difference in pure optical density (OD) among the 4 groups (P = 0.749) however a statistically significant difference was seen between the positive control group and other 4 groups (P < 0.001). Conclusion > The stainless-steel orthodontic bands used in this study were inert as manufactured and even multiple times of sterilization did not decrease the biocompatibility of these bands for clinical use. The present study shows that clinicians can sterilize the tried-in molar bands for at least 8 times without any risk of cytotoxicity for patients.