Evaluation of the effect of two conventional and one herbal mouthwash on the modulus of elasticity of three orthodontic wires: an in vitro study.

Background During fixed appliance therapy, maintaining good oral hygiene is crucial; however, certain mouthwashes can negatively impact orthodontic treatment by altering the mechanical properties of archwires. The study investigated the impact of conventional mouthwashes on orthodontic archwires’ Modulus of Elasticity (MoE). Methods It was an in vitro study that tested MoE of stainless steel (SS), nickel-titanium (NiTi), and β-titanium (β-Ti) archwires after immersing them in chlorhexidine (CHX), sodium fluoride (NaF), and HiORA mouthwashes along with distilled water (control) for one minute daily over three months. The wires were then subjected to a three-point bending test to measure their flexural modulus of elasticity (MoE) while applying loading and unloading forces at 0.5, 1, 1.5, 2, and 2.5 mm deflections. Statistical analysis included two-way ANOVA and Tukey’s Post Hoc test at significant α≤0.05. Results NaF reduced MoE for SS (loading 172.99 ± 7.71 GPa, unloading 148.88 ± 14.65 GPa), NiTi (Loading: 48.42 ± 6.13 GPa, unloading 30.60 ± 4.29 GPa), β-Ti wires (unloading 79.51 ± 1.62 GPa) than Control (loading 185.35 ± 8.06 GPa, unloading 199.78 ± 9.49 GPa) with p<0.05. CHX mouthwash reduced SS (loading -158.58 ± 4.47 GPa, unloading-138.54 ± 6.12 GPa), NiTi (unloading 37.05 ± 2.58 GPa), β-Ti (unloading 81.58 ± 7.94 GPa) with p<0.05. HiORA showed no significant differences in MoE for SS (loading 190.28 ± 7.54 GPa, unloading 185.58 ± 5.35 GPa), NiTi (loading 58.85 ± 2.39, unloading 37.05 ± 2.58), or β-Ti archwire (loading 89.92 ± 2.20, unloading 104.22 ± 5.00) compared to the controls with p<0.05. Conclusion HiORA herbal mouthwash is safe for NiTi, SS, and β-Ti archwires at all stages. Chlorhexidine (CHX) mouthwash should be prescribed briefly to prevent MoE degradation in NiTi and β-Ti archwires. NaF-based rinses should be cautiously used and monitored in SS, NiTi, and β-Ti archwires patients.