RESUMO
AIMS AND OBJECTIVES: To determine the impact on the mechanical properties and surface characteristics of prefabricated 0.016" copper-nickel-titanium (Cu-Ni-Ti) type 35oC (Ormco Company, USA) archwires when subjected to 0.05% sodium fluoride (NaF) mouthwash (ACT Anti-Cavity Fluoride Mouthwash, Sanofi Company, USA) and ozone-infused oil-pulling solution with coconut oil (O3) (O3 Essentials, Health Ranger Store, USA). MATERIALS AND METHODS: Sixty samples of preformed maxillary 0.016" Cu-Ni-Ti archwires were cut at the straight posterior ends for a length of 25 mm and then equally distributed into three groups (n=20). Each group of wires was immersed in distilled water (dH2O), NaF, and O3 solutions for 90 minutes at 37oC. All samples were taken out of their solutions and washed with distilled water prior to testing. On a universal testing device, a three-point bending test was performed on 15 samples. Yield strength (YS), flexural modulus of elasticity (E), and springback ratio (YS/E) were calculated. The remaining five samples from respective solutions were observed under a scanning electron microscope (SEM) for surface topography evaluation. RESULTS: The mean differences in loading YS, E, and YS/E between NaF and O3 are 41.14 MPa, 4.58 GPa, and -0.0006 whereas unloading values are 23.45 MPa, 4.38 GPa, and -0.0004, respectively with a statistical significance of <0.001. Surface topography alteration was appreciated in the NaF mouthwash group compared to the O3 solution. CONCLUSIONS: The mechanical properties of 0.016" Cu-Ni-Ti archwires during loading and unloading were changed after exposure to NaF mouthwash and O3 solution. The mechanical properties of Cu-Ni-Ti archwires were more negatively affected by NaF mouthwash than by O3 solution. Sodium fluoride mouthwash offers more corrosive changes when compared with the O3 solution.
