Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 14 5 2017 12 02 254 258 EN Allahyar Geramy Professor, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Orthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Tabassom Hooshmand Associate Professor, Department of Dental Materials, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Tahura Etezadi Assistant Professor, Department of Orthodontics, School of Dentistry, Mazandaran University of Medical Sciences, Sari, Iran 2017 07 19 2017 09 21 Objectives: The friction between the brackets and orthodontic wire during sliding mechanics inflicts difficulties such as decreasing the applied force and tooth movement and also the loss of anchorage. Therefore, many studies have focused on the factors that affect the friction. The purpose of this study was to assess the effect of 0.05% sodium fluoride mouthwash on the friction between orthodontic brackets and wire. Materials and Methods: Four types of orthodontic wires including rectangular standard stainless steel (SS), titanium molybdenum alloy (TMA), nickel-titanium (NiTi) and copper-nickel-titanium (Cu-NiTi) were selected. In each group, half of the samples were immersed in 0.05% sodium fluoride mouthwash and the others were immersed in artificial saliva for 10 hours. An elastomeric ligature was used for ligating the wires to brackets. The frictional test was performed in a universal testing machine at the speed of 10 mm/minute. Two-way ANOVA was used for statistical analysis of the friction rate. Results: The friction rate was significantly higher after immersion in 0.05% sodium fluoride mouthwash in comparison with artificial saliva (P=0.00). Cu-NiTi wire showed the highest friction value followed by TMA, NiTi and SS wires.   Conclusions: According to the results of the current study, 0.05% sodium fluoride mouthwash increased the frictional characteristics of all the evaluated orthodontic wires. https://fid.tums.ac.ir/index.php/fid/article/view/2063 https://fid.tums.ac.ir/index.php/fid/article/download/2063/969