In vitro evaluation of cytotoxicity of retainer wires used in retaining treatment in orthodontics

Fixed lingual retainer wires used in reinforcing treatment are generally of stainless steel structure and can also be found in gold, titanium, fiber or aluminum silica structure. Stainless steel retainer wires are made of metal alloys with different metallurgical properties and contain elements such as magnesium, chromium and nickel. Retainer wires, which have been shown in many studies to require lifelong retention after treatment, are used in the mouth for a long time. It shows that the retainer wires will stay in the patient's mouth for a long time and that they will interact with teeth, gingival and intraoral fluids for a long time, making the evaluation of their cytotoxic effects important. In our study, seven different fixed lingual retainer wires [(Stainless Steel 6-Strand, G&H Orthodontics, Franklin/ USA), (Strand Flat Lingual Wire, RMO, Denver/ CO), (Retainium, Reliance Orthodontics Products, Itasca/USA), (Bond) A Braid, Reliance Orthodontics Products, Itasca/USA), (Stranded Retantion Wire, Orthoclassic OC, Tokyo/JAPAN), (Flat Lingual Retainer Wire, Orthoessentials, Connecticut/USA), (Dead Soft Retantion Wire, Orthoclassic OC, Reading/USA) )] cytotoxicity was determined using the human gingival fibroblast cell line using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method and the X CElligence real-time cell analysis system. When the cell proliferation values obtained by MTT and X-Celligence methods were examined, the proliferation percentages of the Stranded Retantion Wire (Orthoclassic OC, Tokyo/JAPAN) group were found to be significantly lower than the other groups.