Evaluation of the Effects of Povidone Iodine and Hydrogen Peroxide Mouthwashes on Orthodontic Archwires: An In Vitro Study.

AIM: To evaluate the effects of two preprocedural mouthrinses, hydrogen peroxide (H2 O2 ) and povidone iodine (PI) on the surface characteristics and mechanical properties of nickel-titanium (NiTi) and stainless steel (SS) orthodontic archwires.

MATERIALS AND METHODS: Five wire specimens were used, each (0.016" NiTi, 0.016" SS wires, 0.016 × 0.022" NiTi and 0.016 × 0.022" SS wires) specimen was cut into 30 mm lengths and immersed in 9% of artificial saliva and 91% of two preprocedural mouthrinse solutions: 1.5% hydrogen peroxide mouthwash, 0.2% povidone-iodine mouthwash, and distilled water (control group) for 90 minutes and incubated at 37°C. The wire specimens were then subjected to a three-point bending test for mechanical testing and viewed under a scanning electron microscope (SEM) to evaluate their surface characteristics. The collected data were analyzed using one-way analysis of variance (ANOVA) and Bonferroni post hoc test.

RESULTS: The results showed a significant increase in the flexural modulus (E) of Nitinol wires in povidone-iodine gargle ( p < 0.05) and a significant increase in the E of stainless steel wires in hydrogen peroxide mouthwash ( p < 0.05). Analysis using SEM showed varying qualitative surface changes in the form of corrosion, voids, and ridges on the wires after exposure to both the mouthwashes.

CONCLUSION: Though there were significant changes in the flexural modulus of archwires for both the mouthwashes, hydrogen peroxide did not show a significant difference in the E of wires at most of the deflection intervals when compared with the other two solutions, hence, could be used in orthodontic patients as an effective preprocedural mouthrinse.

CLINICAL SIGNIFICANCE: Preprocedural mouthrinses can cause surface irregularities on the wires which in turn lead to an increase in friction at the bracket-wire interface, thereby disrupting effective tooth movement and extending the orthodontic treatment time.