The Effects of 0.2% Sodium Fluoride and Persica Mouthwashes on Flexural Strength of Nickel-Titanium Orthodontic Wires

Introduction: This study aimed to evaluate the effects of 0.2% sodium fluoride and Persica mouthwashes on the flexural strength and surface characteristics of nickel-titanium (NiTi) orthodontic wires through an in vitro investigation. Materials and Methods: Twenty-seven 0.016-inch NiTi wire samples (3cm long) were divided into three groups (n=9/group): distilled water (control), Persica, and 0.2% NaF mouthwash. Wires were immersed for 90 minutes (simulating 3 months of daily use) and subjected to a three-point bending test (0.5mm/min deflection). Surface changes were analyzed via scanning electron microscopy (SEM). Data were compared using ANOVA and Bonferroni tests. Results: Unloading-phase forces, yield strength, and elastic modulus significantly decreased in NaF and Persica groups versus control (p<0.05), with no differences in loading-phase (p>0.05). SEM revealed the highest corrosion in NaF and the lowest in control. No significant differences were observed between NaF and Persica (p>0.05). Conclusion: Exposure to 0.2% sodium fluoride and Persica mouthwashes adversely affects the mechanical properties and surface integrity of NiTi orthodontic wires. Clinicians should consider the potential implications of prolonged mouthwash use during orthodontic treatment.